Contents of Volume 1 (2014).

Transcription

Online, open access and peer reviewed, Ambientis is an international
interdisciplinary journal of environmental science and ecology
(ISSN 2164-6759).
Editorial Board: María F Barberena, María Cotto, Francisco Márquez, Fred C Schaffner
For more information contact: [email protected]
Contents of Volume 1 (2014).
Message from the Editorial Board
The Nature and Scope of Ambientis.

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page: 1.
Authors: María F Barberena, María Cotto, Francisco Márquez, Fred C Schaffner
Research Articles
Nuevos Fotocatalizadores para la Producción de Hidrógeno.
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pages: 2-13.
Authors: Abraham García, María C Cotto, José Ducongé, Francisco Márquez.
Producción de Biodiesel a partir de Aceites Vegetales.

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pages: 14-19.
Authors: Dayna M Ortiz-Rodríguez, Francisco M Márquez-Linares
Catalytic Photodegradation of p-aminobenzoic Acid on TiO2 Nanowires with High
Surface Area.
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pages: 20-27.
Authors: Loraine M Soto-Vázquez; Tracey Rodríguez; Francisco Márquez.
BBFuels of Puerto Rico, LLC: A sustainable Industrial Model for Bioethanol
Production in Puerto Rico.
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pages: 28-33.
Authors: J Lugo-Vega, JL Nina-Espinosa.
© Copyright 2014, The Authors and Ambientis
Appendix One
Abstracts from the Ambientis Symposium held 7 September 2012
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pages: A-1 through A-23.
Appendix Two
Abstracts from the Ambientis Symposium held 22 November 2013

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pages: A-24 through A-41.
____________________________________________________________________
1
Ambientis 2014: 1-1.
Message from the Editorial Board
The Nature and Scope of Ambientis
María F Barberena, María Cotto, Francisco Márquez, Fred C Schaffner
Editorial Board, Ambientis
Ambientis: an interdisciplinary journal of the environment, is an online,
open access, peer reviewed international interdisciplinary journal of
environmental science and ecology.
Established in 2012, Ambientis will address all aspects of environmental
science and ecology and publishes original papers, short communications and
review papers on ecology, environment and related disciplines, including
chemistry, physics and biology. The journal covers (but is not limited to) research
in environmental pollution, ecotoxicology, chemical and biological remediation,
biomass, biogeochemical cycles with special emphasis in the effects of pollutants
on animals, aquaculture, ethology, environmental pollution, reproduction,
taxonomy, etc. Research on related topics such as microbiology, biochemistry,
genetics of animals and plants, growth, immunology, physiology, and in general
on different chemistry and physics aspects related to the ecology are within the
context of the multi-disciplinary scope of this journal and are welcome.
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Nuevos Fotocatalizadores para la Producción de Hidrógeno
Abraham García, María C Cotto, José Ducongé, Francisco Márquez
Nanomaterials Research Group, Escuela de Ciencias y Tecnología, Universidad del
Turabo, Gurabo, 00778PR, USA
[email protected]
Resumen. El uso de hidrógeno, como reemplazo para combustibles fósiles de los
cuales dependemos hoy día, es de gran relevancia en la actualidad. La importancia de
la generación de hidrógeno tiene no sólo importancia ambiental, sino también
económica. En este estudio, se busca profundizar en nuevos métodos para la síntesis
de nuevos catalizadores para la disociación de agua con producción de hidrógeno, para
ser utilizado como vector de energía. En estudios previos se han utilizado diversas
técnicas para lograr la producción de hidrógeno como por ejemplo la electrólisis, pero
estos mecanismos requieren un alto consumo de energía. En este proyecto se
estudiaron varios materiales fotocatalíticos como posibles alternativas para la
disociación de agua, de modo que puedan tener un mayor potencial de adaptación a
escala industrial. Esta es una característica muy deseable en cualquier proceso de
producción de hidrógeno, dadas las cantidades de combustible fósil que se necesita
reemplazar. Uno de los objetivos de este es la implantación de nuevos métodos de
síntesis para la obtención de nuevos fotocatalizadores. Para la caracterización de los
materiales sintetizados se utilizaron diferentes técnicas de caracterización como la
microscopía electrónica de barrido o SEM (por sus siglas en inglés), microscopía
electrónica de transmisión o TEM (por sus siglas en inglés), área específica por método
BET y la difracción de rayos X o XRD (por sus siglas en inglés). La eficiencia de los
fotocatalizadores obtenidos se determinó evaluando la producción de hidrógeno de la
reacción de ruptura fotocatalítica de agua.
Palabras clave: hidrógeno, fotocatálisis, disolución sólida, ruptura de agua.
New Photocatalysts for Hydrogen Production
Abstract. The use of hydrogen as replacement for fossil fuels, on which we depend
today, is a matter of great relevance. The sustainable generation of hydrogen as fuel is
relevant from an environmental and economic point of view. In this study we have
explored new synthetic routes for developing new photocatalysts to be used in water
splitting, for hydrogen production. Different techniques have been used to produce
hydrogen, such as electrolysis, even though these processes have been found to be
energetically non suitable. In this research various photocatalytic materials were
presented as possible alternatives for using in water splitting processes.
Characterization of the new synthesized materials has been done by using different
experimental techniques including Scanning Electron Microscopy (SEM), Transmission
Electron Microscopy (TEM), surface area BET, and X-ray Diffraction (XRD). The
efficiency of the synthesized photocatalysts was determined by evaluating the hydrogen
evolution by the photocatalytic water splitting reaction.
Keywords: hydrogen, photocatalysis, solid solution, water splitting.
Introducción
La generación de hidrógeno a través de procesos fotocatalíticos es una solución
prometedora al problema energético global. Este proceso tiene la ventaja de no producir
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los problemas ambientales asociados normalmente a la producción de energía
convencional.
El agua es la fuente ideal de hidrógeno. Una de las desventajas actuales es que
la mayoría de los catalizadores conocidos trabajan de forma limitada, funcionando mejor
con luz ultravioleta, no absorbiendo en otras regiones del espectro. La meta principal de
esta investigación es utilizar luz solar para la producción de hidrógeno, por disociación
de agua, mediante nuevos catalizadores. Para alcanzar estos objetivos es necesario,
desarrollar nuevos materiales fotosensibles a luz visible y cuyo proceso catalítico de
ruptura de agua sea eficiente y económico.
La ruptura fotocatalítica de agua para la generación de hidrógeno es un proceso
inocuo para el ambiente, que envuelve el uso de un material semiconductor bajo
radiación solar, a presión y temperatura ambiente. El proceso ha sido reconocido como
una solución prometedora a los problemas globales de producción de energía y
protección ambiental (Ashokkumar 1998). No obstante, la mayoría de los
fotocatalizadores, son más sensibles en la región ultravioleta del espectro o longitudes
de onda cercanas a esta región.
Termodinámicamente, la reacción de ruptura de agua es un proceso complejo.
Este se caracteriza por ser un proceso altamente energético cuya energía libre de Gibbs
es de +237.2KJ mol-1 (Bamberger y Richardson 1974). Durante la reacción se utiliza un
fotocatalizador, que es el material que absorbe la energía responsable del proceso. La
reacción del proceso de ruptura de un mol de agua se muestra a continuación:
H2O  H2 (g) + ½ O2 (g)
(ΔG° = +237.2KJ mol-1)
En 1972, Honda y Fugishima desarrollaron una investigación pionera en este
campo, usando electrodos de TiO2 (Fedorou et al. 1993). Este trabajo fue un claro
ejemplo de prototipo de la técnica. Posteriormente se han desarrollado gran cantidad de
trabajos describiendo el proceso (Forero y Díaz 2007). Más de 140 nuevos
catalizadores han sido desarrollados para producir esta reacción. Algunos de ellos
incluyen óxidos multicompuestos, sulfitos, y nitritos. En todos los casos se ha
demostrado que la eficiencia de conversión es función de un gran número de factores
entre los que se incluyen la cantidad de luz que es absorbida por el catalizador, la
energía de los fotones absorbidos, la eficiencia de la transformación de los fotones
absorbidos en pares electrón-hueco, y cómo estos son transportados a través del
material y hasta la superficie del catalizador, teniendo como resultado la ruptura de la
molécula de agua generando iones hidronio (H+) (Fujishima y Honda 1972). Otros
factores relevantes son la estabilidad y resistencia del catalizador bajo irradiación,
toxicidad y, por razones prácticas, la razón costo-efectividad de los catalizadores.
La eficiencia de la absorción de luz solar es sumamente relevante por lo que
mejorar la composición química, la estructura, y el área específica son factores
importantes a considerar. Estos factores influyen drásticamente sobre las propiedades
ópticas y de transmisión de carga de los catalizadores. La ruptura fotocatalítica de agua
puede lograrse por medio de la utilización de semiconductores de óxidos metálicos.
Esta reacción se produce al promover el movimiento de electrones de la banda de
valencia a la banda de conducción mediante la absorción de fotones con energía una
apropiada (Figura 1).
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Figura 1. Mecanismo del proceso de catálisis para la ruptura de
agua.
Son muchos y muy variados los fotocatalizadores que se han sintetizado y
utilizado para estos fines. Uno de ellos es el sulfuro de cadmio (CdS). El CdS es un
catalizador de mucho interés, ya que se caracteriza por un “gap” de energía muy
pequeño (2.4 eV) y además tiene una banda de conducción cuyo potencial es eficiente
para llevar a cabo el proceso de reducción de agua a hidrógeno (Kalyanasundaram et
al. 1978, Masa et al. 2011). No obstante, este catalizador presenta graves
inconvenientes para su uso por la alta toxicidad e inestabilidad del mismo. Además,
debido a la presencia de H+, puede producirse la fotocorrosión del CdS, con formación
de iones Cd2+ y S-2 (Kalyanasundaram et al. 1978, García-Cerda et al. 2003).
CdS +2H+  Cd+2 + S
(2)
El sulfito es necesario como agente coadyuvante del proceso fotocatalítico, para
que reaccione con los pares electrón-hueco de las bandas de valencia y conducción,
evitando la degradación del catalizador (Kalyanasundaram et al. 1978, García-Cerda et
al. 2003). En este sentido, la incorporación de otros metales en la estructura del CdS,
con obtención de soluciones sólidas, puede ser una estrategia interesante para mejorar
las propiedades catalíticas de este material (Nayeem et al. 2001). La energía potencial
de las bandas de valencia y conducción puede ser controlada específicamente, cuando
los electrones absorben la energía necesaria, para saltar a la banda de conducción,
dejando un hueco en la banda de valencia. En los fotocatalizadores la corriente eléctrica
se genera por el paso de electrones libres de la banda de conducción y por el
desplazamiento de los electrones en la banda de valencia. Resultados muy interesantes
basados en catalizadores de CdZnS ya han sido obtenidos. Se espera que funcionen
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mejor cuando se incorporen a su estructura elementos metálicos adicionales como Pt ó
Ru (García-Cerda et al, 2011).
Se ha observado que el sulfuro de molibdeno (MoS2) actúa como agente cocatalizador para CdS, mejorando en gran medida la ruptura fotocatalítica de la molécula
de agua. Otro metal de transición estudiado por sus interesantes propiedades es el
wolframio (W). Este elemento es un buen componente activo, para la fotoruptura del
agua. WS2 tiene propiedades similares a MoS2 como agente co-catalizador, mejorando
significativamente la actividad fotocatalítica de CdS en la producción de hidrógeno. El
WS2 y MoS2 tienen propiedades similares como sulfuros de metales de transición. Esto
se debe a que poseen una estructura cristalina parecida, al igual que sus propiedades
químicas. El W 2+ o Mo2+ se han utilizado para inducir cambios en la morfología
superficial y actividad fotocatalítica del CdS, promoviendo la separación de electrones y
generación del par electrón-hueco, limitándose la recombinación mediante este dopaje
(Zong et al. 2011).
El objetivo principal de esta investigación es analizar el diseño de nuevas rutas y
procesos químicos para la síntesis de catalizadores activos en procesos de ruptura de
agua. Además caracterizar estos nuevos materiales en la aplicación de procesos para la
ruptura de agua y la evaluación de su eficiencia en la producción de hidrógeno.
Método Experimental
Solución Sólida de ZnCdS
El fotocatalizador de ZnCdS se sintetizó por coprecipitación de CdS y ZnS,
usando Na2S·9H2O como agente precipitante. Los precursores a emplear serán
Cd(CH3COO)2 y Zn(CH3COO)2, que fueron disueltos en agua desionizada (Nayeem et
al. 2001) (Milli-Q) para obtener una solución 0.3 M. Estas dos soluciones se lograron
homogenizar mediante agitación magnética durante 20 min, en un baño suave de
ultrasonido. Al finalizar los 20 min, se añadió Na2S.9H2O (5% en H2O) y se mantuvo
esta nueva mezcla por 40 min en agitación. El precipitado de la mezcla fue separado
por medio de centrifugación y lavado nuevamente con agua desionizada. Este proceso
de lavado final se repitió 5 veces. La muestra se secó a una temperatura de 80 °C y
finalmente se trató térmicamente en flujo de nitrógeno a diversas temperaturas y por
diferentes periodos de tiempo. Los catalizadores obtenidos tuvieron diferentes
relaciones atómicas dependiendo de la síntesis: Cd1-xZnxS (0.4 > x y x > 0.1).
Una vez que los diferentes catalizadores fueron sintetizados, estos se
caracterizaron por diferentes técnicas como microscopía electrónica de barrido (SEM),
microscopía electrónica de transmisión (TEM) y difracción de rayos X (XRD).
Finalmente, estos catalizadores se probaron en la reacción de ruptura fotocatalítica de
agua, usando diferentes longitudes de onda de irradiación y determinándose la cantidad
de hidrógeno producido. La reciclabilidad del catalizador es un factor relevante para su
potencial uso, por lo que la actividad fue evaluada después de diferentes ciclos de
reacción.
Solución Sólida de ZnCdFeCuS
En esta síntesis fue empleado CuNO3, como precursor de Cu. La mezcla de
reacción se sometió a agitación durante 20 min en un baño de ultrasonido (Nayeem et
al. 2001). A continuación se adicionó Na2S.9H2O (5% en agua), y la mezcla se dejó en
baño de ultrasonido durante 50 min. En adición se le incorporó a la solución FeCl3 con
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las mismas condiciones con un tiempo de 60 min. El sólido obtenido fue centrifugado
para separarlo de la solución y seguidamente se lavó varias veces con agua destilada
(al menos cinco veces) y con etanol (dos veces). El catalizador obtenido fue secado en
un horno a 80 °C durante 24 horas y posteriormente se expuso a un flujo de nitrógeno a
diferentes tiempos y temperaturas (Figura 2).
Los fotocatalizadores sintetizados fueron sometidos a diversas pruebas de
laboratorio para evaluar la actividad en la producción de hidrógeno.
Una determinada cantidad de fotocatalizador, se introdujo en un matraz de
cuarzo y se suspendió en agua. A la suspensión se le añadió un electrolito de sacrificio
que facilitará el proceso. El matraz se irradio con una fuente de luz visible, previamente
filtrada para seleccionar una determinada longitud de onda de irradiación. El uso de
estos filtros permite irradiar la solución mediante longitudes de onda específicas de 220,
280, 320, 400, 500, 600 y 700 nm. Durante el proceso de fotólisis, el gas generado es
bombeado mediante un sistema mecánico a un cromatógrafo de gases (GC) dotado de
un sistema de detección por conductividad térmica.
Figura 2. Diseño experimental para las pruebas catalíticas de
ruptura de agua.
Resultados y Discusión
Caracterización de los Catalizadores
Se sintetizaron nuevos catalizadores para su uso en la ruptura de agua a través
de un proceso de co-precipitación bajo diferentes condiciones experimentales. Estos
catalizadores han sido caracterizados mediante microscopia electrónica de barrido
(SEM), análisis de área superficial BET (Brunauer–Emmett–Teller) y difracción de rayos
X (XRD).
Muestra M-2
Diversos metales de transición (Cd, Zn, Fe, Cu), se han utilizado como
precursores para la síntesis de esta muestra. El tiempo de síntesis ha sido de 130 min a
una temperatura de 40 ºC. En la Figura 3 se puede observar el tamaño de las partículas
y la superficie de las mismas. Además se observa una aglomeración de las partículas,
caracterizadas por presentar diámetros no uniformes que oscilan entre 0.15 μm y 0.30
μm. El área de superficie medida para esta muestra fue de 567 m2/g (Tabla 1).
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Figura 3. Imágenes SEM de la Muestra M-2 a (a) 16,000x, (b)
20 000x y (c) 1700x .
Tabla 1. Área de superficie de los fotocatalizadores sintetizados.
Muestra
ÁreaBET (m2 g-1)
M-2
567
M-3
532
M-4
521
En el difractograma de la Muestra M-2 (Figura 4) se observa la presencia de
reflexiones a valores intermedios a los correspondientes a CdS y ZnS, lo que puede ser
justificado debido a la presencia de estos elementos en forma de óxidos mixtos en
disolución sólida.
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Figura 4. Difractograma de la muestra M-2.
Muestra M-3
Este catalizador, a diferencia de la muestra M-2, el tiempo de reacción se
aumentó a 160 min, a una temperatura de 40 ºC. En la Figura 5 podemos observar las
imágenes SEM de la Muestra M-3. El tamaño de partícula de esta muestra es
Figura 5. Imágenes SEM de la muestra M-3 a una
magnificación de (a) 5000x, (b) 7500x y a (c) 22 000x.
claramente mayor que en la muestra M-2, mostrando diámetros próximos a 2.5 μm. Al
utilizar una magnificación mayor (Figuras 4-b y 3-c) se observa que las partículas
poseen una forma irregular y una aparente dispersión de tamaños. El área de superficie
medida para esta muestra fue de 532 m2 g-1 (Tabla 1).
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En la Figura 6 se presenta el difractograma correspondiente a la Muestra M-3.
Como sucedía para la muestra M-2, se observan reflexiones a valores intermedios a los
correspondientes a los precursores CdS y ZnS, lo que se justifica debido a la presencia
de estos elementos como disoluciones sólidas de óxidos mixtos.
Figura 6. Difractograma de la Muestra 3 donde pueden
observarse los picos representativos del fotocatalizador.
Muestra M-4
Para la síntesis de este catalizador se mantuvo el tiempo de reacción a 130 min,
a una temperatura de 40 ºC. A diferencia de las dos síntesis previas, la reacción se
desarrolló empleando un sistema de ultrasonido de sonda a una potencia media de 375
W.
En la Figura 7 se presentan las imágenes SEM del catalizador M-4.
Aparentemente el diámetro de partícula de este catalizador es intermedio respecto a las
muestras anteriores, con valores próximos a 0.5 μm. El aspecto compactado de esta
muestra (ver Figura 5-c), a diferencia de la M-2 y M-3, podría deberse al empleo de
ultrasonido durante la síntesis. El área de superficie determinada para esta muestra fue
de 521 m2 g-1 (Tabla 1).
10
Figura 7. Imágenes SEM de la muestra M-4 a diferentes
magnificaciones: 4500x (a), 7500x (b) y 1200x (c).
En la Figura 8 se presenta el difractograma obtenido para la Muestra M-3. De la
misma forma que sucede en las muestras anteriores, las reflexiones se presentan a
ángulos intermedios a los esperados para los precursores de CdS y ZnS, lo que justifica
la presencia de estos elementos como disoluciones sólidas de composición
homogénea.
Figura 8. Difractograma de la Muestra M-4.
Actividad Catalítica
Uno de los objetivos principales de esta investigación es determinar la eficiencia
para la producción de hidrógeno de los catalizadores sintetizados. Previo al experimento
11
los catalizadores deben ser activados. Para este propósito las muestras fueron tratadas
térmicamente en un flujo de nitrógeno a varias temperaturas (400, 700 y 900 ºC). Para
determinar la eficiencia del fotocatalizador en la producción de hidrógeno estos fueron
irradiados empleando filtros para la selección de las longitudes de onda deseadas.
La producción máxima de hidrógeno utilizando el catalizador M-2 fue de 1300
µm h-1g-1. Esta producción se midió bajo irradiación a 400 nm (Figura 9).
Figura 9. Producción de hidrógeno obtenida bajo irradiación
con diferentes longitudes de onda empleando el catalizador
M-2.
La Figura 10 muestra la curva de producción de hidrógeno al utilizar como
fotocatalizador la Muestra 3. En las muestras irradiadas con un largo de onda
aproximado de 500 nm se obtuvo una concentración de hidrogeno equivalente a1400
µm h-1g-1.
12
Figura 10. Producción de hidrógeno obtenida bajo irradiación
con diferentes longitudes de onda empleando el catalizador M3.
La Muestra 4 también fue sometida al mismo proceso de evaluación. En este
caso, la concentración de hidrógeno producido por la muestra fue de 1650 µm h-1g-1. La
longitud de onda a la cual se obtuvo esta cantidad de hidrógeno fue de
aproximadamente unos 600 nm (Figura 11). Por los resultados obtenidos podemos
determinar que la mejor temperatura de activación para los fotocatalizadores
sintetizados es de 700 ºC (Figura 9, 10 y 11).
Figura 11. Producción de hidrógeno obtenida bajo irradiación con
diferentes longitudes de onda empleando el catalizador M-4.
Conclusiones
En este trabajo se lograron alcanzar los objetivos propuestos, que incluyen: el
desarrollo y síntesis de nuevos fotocatalizadores para producción de hidrógeno a través
de la ruptura de agua, y las pruebas fotocatalíticas con las que verificamos el potencial
de estos nanomateriales. Encontramos que las concentraciones de precursor y el
tiempo de reacción del proceso de síntesis del catalizador son parámetros
experimentales de importancia crucial, afectando la morfología y actividad catalítica de
las nanoestructuras. Por otra parte, se ha comprobado que la temperatura de
tratamiento para el proceso de activación es crítica para mejorar la eficiencia de la
ruptura catalítica del agua. Este trabajo abre nuevas e interesantes expectativas para el
futuro empleo de otros óxidos metálicos en procesos de síntesis de nuevos
catalizadores con altas prestaciones.
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Producción de Biodiesel a partir de Aceites Vegetales
Dayna M Ortiz-Rodríguez, Francisco M Márquez-Linares
Nanomaterials Research Group, School of Science and Technology, Universidad del
[email protected], [email protected]
Resumen. Uno de los grandes impactos que ha tenido el ser humano en el mundo es la
consecuencia del uso de los recursos naturales del planeta, cuya finalidad ha sido el
abastecimiento energético para el desarrollo económico y tecnológico. Este desarrollo
económico ha causado un aumento en la demanda de bienes y servicios en países
industrializados, y a su vez ha provocado un aumento en el consumo per cápita de energía a
nivel mundial. Por tal razón, es muy importante el desarrollo de nuevas alternativas energéticas,
para reducir la dependencia actual con el petróleo y al mismo tiempo disminuir el impacto de las
emisiones de gases de efecto invernadero al medio ambiente. Como alternativa al uso de
combustibles fósiles se encuentra el biodiesel, que es biodegradable, eco amigable, y
económico. El biodiesel puede ser producido, por medio de la reacción de transesterificación de
un aceite vegetal nuevo o usado (por ejemplo de girasol, maíz u oliva) con un alcohol de cadena
corta (metanol) en presencia de un catalizador (NaOH). En el presente trabajo hemos obtenido
biodiesel procedente de estos tres tipos de aceites vegetales que han sido posteriormente
caracterizados. Se han realizado diversas pruebas de calidad y eficiencia para garantizar la
calidad del biodiesel obtenido. Los resultados obtenidos indican que el aceite de girasol es el que
proporciona una mejor eficiencia al biodiesel de síntesis, seguido por el de maíz y el de oliva. Las
emisiones de CO2 que podrían afectar el medio ambiente fueron, en todos los casos, inferiores al
4.1%.
Palabras clave: Biodiesel, transesterificación, aceites vegetales, prueba de calidad, eficiencia.
Production of Biodiesel from Vegetable Oils
Abstract. One of the major impacts that humans have had on the world is the consequence of the
use of natural resources of the planet, whose purpose has been the energy supply for economic
and technological development. This economic development has caused an increase in the
demand for goods and services in industrialized countries, and in turn has led to an increase in
per capita consumption of energy worldwide. For this reason, it is very important to develop new
energy alternatives to reduce the actual dependence on petroleum and, at the same time, reduce
the impact of emissions of greenhouse gases to the environment. An alternative to using fossil
fuels is biodiesel, which is biodegradable, eco-friendly, and represents an economical source of
energy. Biodiesel may be produced by the transesterification reaction of new or used vegetable
oils (for example sunflower, corn, or olive oil) with a short chain alcohol (methanol) in the
presence of a catalyst (NaOH). In the present work we have synthesized biodiesel from these
three types of vegetable oils that have been subsequently characterized. Different chemical tests
have been used to ensure the quality of the biodiesel obtained. The results indicate that
sunflower oil provided better efficiency biodiesel, followed by corn and olive oils. CO 2 emissions
that could affect the environment were, in all cases, less than 4.1%.
Keywords: Biodiesel, transesterification, vegetable oils, quality test, efficiency.
Introducción
El impacto ocasionado en el medio ambiente por el uso de combustibles fósiles
ha motivado la necesidad de buscar otros tipos de energías sostenibles. El biodiesel
representa una de las alternativas más interesantes. El biodiesel (fundamentalmente
basado en ésteres metílicos de ácidos grasos) es un combustible que se puede
sintetizar por transesterificación de los triglicéridos de aceites vegetales, grasas
animales, o incluso a partir de aceites o grasas procedentes de residuos vegetales o
15
animales (Shi y Wang 2012). En las grasas animales y aceites vegetales hay una
mezcla variable de ácidos grasos y triglicéridos, es decir tres cadenas moleculares
largas de ácidos grasos unidas a un alcohol, y glicerol (García 2007). En la reacción de
transesterificación (Figura 1), una molécula de triglicérido reacciona con tres moléculas
de alcohol (normalmente metanol o etanol) para dar tres moléculas de monoésteres y
una de glicerol; obteniéndose así un aproximado del 10% de glicerina y un 90% de
biodiesel del producto total (García 2007).
Figura 1. Reacción de Transesterificación.
El glicerol producido en la reacción de transesterificación, una vez recuperado y
refinado puede emplearse en distintos sectores entre los que destacan la industria
química (plásticos, pinturas, conservantes), cosmética, y farmacéutica (Larosa 2001). El
uso de biodiesel presenta importantes ventajas frente a otros combustibles derivados
del petróleo. Su índice de cetano es más alto que el del diesel de petróleo, no contiene
azufre, reduce las emanaciones de CO2, CO, partículas e hidrocarburos aromáticos, en
caso de accidente los vertidos son menos contaminantes que los de combustibles
fósiles, es biodegradable y su transporte y almacenamiento resulta más seguro que el
de los petroderivados, ya que posee un punto de ignición más elevado (Rodríguez et al.
2011).
Experimental
Materiales
Se utilizaron tres aceites vegetales nuevos: aceite de oliva 100% extra virgen,
aceite de girasol y aceite natural de maíz 100% puro. NaOH (hidróxido de sodio) se
utilizó en pellets y fue proporcionado por Fisher Scientific, 99.3%. Metanol anhidro fue
proporcionado por Fisher Scientific (99.9%). Las mediciones de pH se realizaron
mediante un pH-metro de electrodo (Mettler Toledo). Las medidas de viscosidad se
realizaron empleando un viscosímetro tipo Cannon Fenske. Las mediciones de
eficiencia y emisión de gases se realizaron empleando un motor diesel de pruebas
“Gunt Hamburgo CT110”.
Procedimiento
Una cantidad apropiada de catalizador (NaOH) se mezcló con 100 mL de
metanol, para obtener metóxido de sodio (CH3ONa). A continuación se midieron 500 mL
de cada aceite vegetal (girasol, oliva y maíz), los cuales se calentaron hasta alcanzar
una temperatura de 70 °C. Cuando la temperatura del aceite se estabilizó a 70 °C
16
alcanzó dicha temperatura, y después de transcurrir un tiempo adecuado, se dejó
reposar hasta que la temperatura quedó estabilizada a 40 °C. A continuación, a cada
aceite previamente tratado a temperatura, se adicionó la disolución de metóxido sódico.
La mezcla se mantuvo en agitación magnética durante 2 horas a 40 °C, dando como
resultado disoluciones homogéneas. Estas disoluciones fueron introducidas en sendos
embudos de decantación. Con objeto de facilitar la separación de fases, las
disoluciones se mantuvieron en estos embudos durante un mínimo de 48 horas. Como
resultado, se formaron dos fases diferentes que pudieron ser separadas (ver Figura 2).
Figura 2. Formación de dos fases tras la reacción de
transesterificación: glicerina en la parte inferior y el biodiesel
de síntesis en la parte superior.
Pruebas de Calidad
Para comprobar la calidad del biodiesel obtenido se realizaron diversas pruebas.
La prueba de metanol consistió en mezclar 5 mL de biodiesel con 45 mL de metanol.
Dicha mezcla se agita moderadamente durante unos segundos. Si hay residuos de
aceite en el fondo del recipiente, significa que no todo el aceite ha reaccionado con el
CH3ONa. La prueba de agua, consistió en mezclar 10 mL de agua con 10 mL de
biodiesel. Esta mezcla se agita moderadamente durante unos segundos dando lugar a
la formación de dos capas claramente separadas. La no aparición de estas dos fases
puede deberse a que las reacciones no se han completado, y/o al uso de exceso de
catalizador. Como era de esperar, ninguno de los tres biodiesel obtenidos pasó las
pruebas de calidad de metanol y agua, por lo que fue necesario reprocesarlos (Knothe
2005).
El reprocesado se realiza mediante la adición de metanol, en una proporción
adecuada, al biodiesel producido. La mezcla se homogeneiza mediante agitación
magnética y se calienta moderadamente a 40 °C. A continuación, la mezcla de reacción
se transfiere a un embudo de decantación y se deja en reposo durante un día. La
glicerina es, de nuevo, separada del biodiesel, y se vuelven a realizar las primeras dos
pruebas de calidad. Después de este nuevo procesado, el biodiesel obtenido a partir de
las tres muestras de aceite cumplió con las mismas. El reprocesado se debe llevar a
cabo cuando no todo el aceite vegetal reacciona por completo con el alcohol. Si hay
17
aceite sin reaccionar en el biodiesel podría aumentar la viscosidad y bajar en el punto
de ignición, dando lugar a posibles efectos adversos para el motor (Addison 2002). Una
vez que el biodiesel pasó las primeras dos pruebas de calidad (ver Figura 3), se
procedió al lavado del mismo. Se realiza una prueba de lavado, para cada biodiesel,
con 1/3 de agua por cada 50 mL de biodiesel. Después de agitar esta solución durante
5 minutos, en un agitador magnético, la mezcla se introduce en un embudo de
separación durante 1 hora. En el embudo de separación se aprecia el agua en la parte
inferior y el biodiesel en la parte superior. La separación de las dos fases se produjo de
manera correcta por lo que se continúa con el lavado del lote completo (ver Figura 4).
Después del lavado del lote completo del biodiesel se determinó su viscosidad a las
temperaturas de 20 °C y 40 °C. El pH debe ser aproximadamente 7.00 (neutro), puesto
que de lo contario se podrían dañar las válvulas del motor (Addison 2002). En todos los
casos, el pH del biodiesel estuvo en un intervalo próximo al ideal (6.80 a 7.20).
El siguiente paso es secar el biodiesel. El secado es importante para asegurar la
completa eliminación de agua y cualquier otro residuo presente que pueda afectar al
posterior uso del biodiesel. El procedimiento consistió en calentar el biodiesel a 48 °C
para evaporar el agua residual presente en el biodiesel. Si el biodiesel obtenido no tiene
turbidez y presenta una apariencia cristalina, es una buena señal de que los residuos de
agua se han evaporado y el mismo está limpio y listo para ser utilizado. El biodiesel
sintetizado en este trabajo mostró esas características. Por último, se realizaron las
pruebas de eficiencia y emisión de gases en un motor diesel de pruebas “Gunt
Hamburgo CT110”.
Figura 3. Pruebas de calidad de metanol (a) y agua (b), después
del reprocesamiento del biodiesel.
18
Figura 4. Lavado del lote completo.
Resultados y Discusión
Es importante mencionar que las reacciones se desarrollaron empleando
diferentes cantidades de catalizador. Las reacciones de síntesis se desarrollaron en
medio básico y, para ello, se emplearon diversas cantidades de NaOH (0.25 g, 0.50 g,
1.00 g y 1.75 g). Los mejores resultados se obtuvieron utilizando 1.75 g de NaOH. En
estas condiciones, se produjo menos jabón en la prueba de agua y en el lavado, y se
formó menos cantidad de aceite sin reaccionar, en la prueba de metanol. La prueba de
viscosidad dinámica se realizó en los aceites a dos temperaturas: 20 °C y 40 °C. La
viscosidad de un fluido es la medida de su resistencia, a desplazarse de un lugar a otro
(Ferreira et al. 2009). A mayor temperatura menor es la viscosidad del biodiesel. El
biodiesel de aceite de oliva obtuvo una mayor viscosidad en ambas temperaturas. Él
biodiesel de girasol tiene la menor viscosidad a 20 °C, y el biodiesel de maíz tiene la
menor viscosidad a 40 °C. Con relación, a las pruebas de eficiencia y de emisión de
gases, el biodiesel de girasol obtuvo la mejor eficiencia, seguido por el de maíz, y por
último el de oliva, que además de ser el de menor eficiencia, también fue el que produjo
mayor cantidad de emisiones de CO y CO2.
Conclusión
El biodiesel producido a partir de aceites de maíz, girasol y oliva pasó las
pruebas de calidad. Las pruebas de viscosidad revelaron que a 20 °C el biodiesel de
girasol muestra una viscosidad más baja. A 40 °C, el biodiesel de maíz tuvo una
viscosidad baja, por lo que, previsiblemente, tanto el de girasol como el de maíz podrían
ser los más apropiados para su posterior uso. El estudio de la eficiencia de las muestras
de biodiesel obtenidas a partir de los tres aceites vegetales ha permitido establecer que
el biodiesel más apropiado es el obtenido a partir de girasol, seguido por el maíz y por
último el de oliva. El biodiesel de oliva, debido a su elevada viscosidad, podría tener
efectos negativos que afecten a la eficiencia del motor.
En general, las pruebas de emisión de gases resultaron ser positivas,
demostrando que el biodiesel sintetizado emite un volumen mínimo de gases, en
comparación con los combustibles fósiles.
19
Agradecimientos
Los autores agradecen el apoyo financiero proporcionado por el Departamento
de Energía a través del proyecto Massie Chair en la Universidad del Turabo. DO
agradece a la Escuela de Ciencias y Tecnología de la Universidad del Turabo, por la
ayuda como Asistente de Cátedra.
Referencias Citadas
Addison K. 2002.Biodiesel and your vehicle. Journey to forever. [Internet]. [cited 2013
Oct 21].Available from:
http://journeytoforever.org/biodiesel_ vehicle.html#reprocess.
Ferreira AP, da Costa CR, do Espírito DM, Real JR, Guimares PR, Paraguassu LH.
2009. Metrological approach in the characterization of viscosity of corn biodiesel
relative to temperature, using capillary viscometers. Fund App Metrology.
(34):102-106.
García JZ.2007. Evaluación de materiales vegetales y residuales oleaginosos para la
producción de biodiesel en el Salvador. Universidad de El Salvador, El Salvador.
20-22.
Knothe G, Gerpen VJ, Krahl J.2005. The Biodiesel Handbook.1 Edition, AOCS Press,
Illinois, USA.
Larosa R J.. Proceso para la Producción de Biodiesel. ZOE Tecno Campo. [Internet]
2001. [cited 2013 Oct 25]. Available from:
http://www.zoetecnocampo.com/Documentos/biodie_lar/ biodie_lar.htm.
Rodríguez MC, Osario M, Obón JM, Alacid MC. 2011. Enseñando tecnologías: Biodiesel
a partir de aceites usados. II Jornadas sobre la enseñanza de las ciencias y las
ingenierías 1-10.
Shi H, Yuan M, Wang T.2012. Design of biodiesel production processes bybase
catalyzed transesterification. Adv Mat Res. (512-515): 510-514.
20
Catalytic Photodegradation of p-aminobenzoic Acid on TiO2 Nanowires with
High Surface Area
Loraine M Soto-Vázquez; Tracey Rodríguez; Francisco Márquez
Nanomaterials Research Group, School of Science and Technology, Turabo University,
Gurabo PR 00778, USA
[email protected]; [email protected]; [email protected]
Abstract. Pharmaceutical personal care products (PPCP’s) production and consumption have
increased exponentially in recent years due to medicine and technology advances related to the
development of dangerous skin diseases such as cancer. These PPCP’s usually are found in
wastewaters and their removal represents a very important environmental issue. With the aim of
studying the possible degradation of these compounds, we have synthesized TiO 2 nanowires
(rutile phase) that have been fully characterized by BET measurements, XRD and SEM and used
in the photodegradation reaction of p-aminobenzoic acid (PABA). The photocatalytic degradation
of PABA has been studied under different experimental conditions (i.e. catalyst loading). The
photocatalytic reaction was monitored as a function of time by UV-Vis spectroscopy. The highest
-1
degradation rate occurred with 1.0 g L of catalyst while the reaction does not proceed without
radiation or in absence of the catalyst. The present work demonstrates that p-aminobenzoic acid
could be successfully degraded in a relatively short time period with high degradation
percentages.
Keywords: p-aminobenzoic acid; UV-Vis spectroscopy; photocatalysis; TiO2
Fotodegradación Catalítica de Ácido P-Aminobenzóico Mediante Nanohilos de
TiO2 de Alta Área Superficial
Resumen. La producción y consumo de productos farmacéuticos y de cuidado personal han
aumentado exponencialmente en los últimos años principalmente por los avances médicos y
tecnológicos relacionados con el desarrollo de enfermedades peligrosas de la piel como cáncer.
Estos productos se han encontrado cada vez más frecuente en aguas residuales y su remoción
representa un verdadero problema ambiental. Con la idea de estudiar la posible degradación de
estos compuestos se sintetizaron nanohilos de TiO 2 en fase rutilo que fueron posteriormente
caracterizados mediante medidas de área BET, DRX y SEM y usados en la reacción de
fotodegradación del ácido p-aminobenzoico.
La degradación fotocatalítica del ácido paminobenzoico se estudió bajo diferentes condiciones experimentales (por ejemplo, la
concentración de catalizador). La reacción fue monitoreada mediante espectroscopía UV-1
Visible. La tasa de degradación más alta ocurrió con 1.0 g L de catalizador, mientras que la
reacción no tuvo lugar en ausencia de radiación o sin el catalizador. En el presente trabajo se
demuestra que ácido p-aminobenzoico puede ser degradado eficientemente en períodos
relativamente cortos.
Palabras clave: ácido p-aminobenzoico; espectroscopia UV-Visible; fotocatálisis; TiO2
Introduction
In recent years pharmaceutical personal care products (PPCP’s) production have
grown exponentially. PPCP’s include among others, lotions, pharmaceutical drugs,
veterinary products and sunscreen products (An and Zhou 2012). These PPCP’s should
have an active ingredient that can be organic or inorganic in nature. Because of the
overconsumption PPCP’s usually are found in wastewaters (Hu et al. 2011). Organic
active ingredients have a cromophore responsible for the absorption of sun radiation;
these include benzophenone-3, octocrylene and p-aminobenzoic acid (PABA). PABA
was widely used in the 70’s as a sunscreen agent but in the 80’s a group of researchers
found that PABA was a disruption agent against DNA cells.
21
With technology advances new remediation techniques have been explored and
developed. Traditional remediation processes have demonstrated to be good with some
organic pollutants but not enough with persistent organic pollutants such as those
present in PPCP’s (Lu et al. 2011). Some of the new developed technologies are the
Advanced Oxidation Processes (AOP’s). AOP’s are carried out using a catalyst
(semiconductor) with a wide band gap. OH radicals are generated in the presence of
radiation and an oxidation agent, mediated by electron-hole pairs (Vinu and Madras
2010). These hydroxyl radicals are very reactive species responsible for the degradation
of organic substances. One of the AOP’s widely studied is the photocatalytic
degradation which has been demonstrated to be a successful technique in the
degradation of phenol, organic dyes, phenanthrene and other emerging contaminants
(Lin et al. 2011; Zhang et al. 2011; Rivas et al. 2012; Sharma et al. 2012).
Within photocatalytic processes there are countless alternatives to be used as
semiconductor materials. Photocatalytic degradation has been studied using ZnO, ZnS,
FeCu/Cu2O and TiO2 (Hu et al. 2011, Maji et al. 2011, An and Zhou 2012, Tang 2013).
TiO2 has been extensively used due to its appropriate band gap, cost-effectiveness, low
toxicity and easy synthesizing process. Chen and Mao (2007) stated the vast uses that
TiO2 could have including photovoltaic applications, water splitting process and
hydrogen storage, among others.
In this research we have synthesized and characterized TiO2 nanowires (TiO2
NWs) that were employed in the photocatalytic degradation of PABA. The present work
demonstrates that p-aminobenzoic acid can be successfully degraded in short time
periods with high degradation percentages.
Methods and Materials
Chemicals
All reagents used in the present study were of analytical grade. HCl 37% was
provided by ACROS. Hydrogen Peroxide 50% was provided from Fisher Scientific. 4aminobenzoic acid (PABA), TiCl4, HCl 1.0 M, Acetone and Isopropyl Alcohol were
provided by Sigma-Aldrich and used without further purification. Ultra pure water [(MilliQ water, 18.2 MΩ.cm-1 at 25 °C (298 K)] was used in all experiments. The substrate
selected for the hydrothermal growth of TiO2 NWs was silicon (100) wafer of p-type
(boron-doped).
Experimental Procedure
In a typical synthesis of TiO2 NWs, Si(100) substrates were rinsed with isopropyl
alcohol, acetone and finally water. HCl 37% was diluted in water to 35%, then a 1:1
solution of HCl 35%:H2O was prepared and homogenized during 10 minutes. 3.5 mL of
TiCl4 were added dropwise and kept under vigorous agitation during 15 minutes. The
solution was added to a Teflon liner contained on an autoclave with the substrates
placed in the bottom. The autoclave was exposed to 180 °C (453 K) during two hours.
After cooling to room temperature the autoclave was open and the substrates with the
TiO2 NWs grown on the surface were rinsed several times with distilled water and dried
at 60 °C (333 K) overnight. The TiO2 NWs were characterized by Scanning Electron
Microscopy (SEM), Brunauer–Emmett–Teller (BET) specific area measurements and XRay Diffraction (XRD).
22
The effect of the catalyst loading on the photodegradation reaction was studied
by adding different amounts of TiO2 NWs to a 5.0 x 10-5 M solution of PABA followed by
30 minutes of continuous stirring to allow the system to reach the adsorption-desorption
equilibrium. The pH was adjusted to 3 with 0.5 M HCl. Finally H2O2 was added followed
by bubbling air into the solution. The photocatalytic reactor consists of six light bulbs
surrounding the system with continuous agitation and two mirrors to reflect the light. The
photocatalytic degradation was monitored during 3 hours by taking aliquots at different
reaction times that were subsequently analyzed by UV-VIS spectroscopy.
Results and Discussion
TiO2 NWs characterization
SEM images of the synthesized TiO2 NWs with magnifications ranging from
1,000X to 20,000X show that the synthesized catalyst is organized as single nanowires
grouped in arbitrary directions (Figure 1). Each nanowire has approximately one to five
microns of length and widths of ca. 300 nm. The apparent disordered growth of the
nanowires leads to a material with high surface area. The Brunauer-Emmett-Teller
Figure 1. SEM images of the as-synthesized TiO2 NWs obtained at
different magnifications: (A)1000X, (B) 5000X, (C)100 00X, and
(D) 20 000X.
(BET) surface area of the as-synthesized TiO2 NWs was determined by N2 adsorptiondesorption isotherm measurement at 77 K. Surprisingly, the specific area of the TiO2
NWs was found to be higher (ca. 584 m2 g-1) than that expected. To our best knowledge
the synthesized nanowires are one of the materials based on TiO2 with higher surface
area.
23
The structure and crystal phase of the synthesized TiO2 NWs have been
characterized by XRD. A typical XRD pattern is shown in Figure 2. As can be seen
there, the major peaks are located in the 2θ range of 20º - 70º, matching well the
diffraction data of pure rutile phase since no extraneous peaks were detected.
Figure 2. X-Ray diffraction pattern of the as-synthesized TiO2NWs.
Photocatalytic Experiments
The peak at 282 nm in the UV-vis spectrum was used as the indicator of the
photodegradation. The effect of catalyst loading was studied by adding different amounts
of TiO2 NWs (from 0.4 g L-1 to 1.2 g L-1) to the reaction mixture. The photodegradation of
PABA was also tested without the presence of catalyst and without radiation source.
Results obtained for the degradation of PABA under different experimental conditions
(Figure 3) show that the absence of catalyst or of the irradiation source produces
minimal change in the levels of PABA because the electron-hole pairs are not generated
or at least not in sufficient quantity. Also in absence of the radiation source that
activates the catalyst the radical species cannot be generated and the reaction does not
proceed (Figure 3). Moreover, different amounts of catalyst in the reaction mixture lead,
as a result, at different levels of photodegradation of PABA. The largest degradation
occurs using 1.0 g L-1 of catalyst (Figure 3). This result can also be seen in the final
degradation percentage as a function of catalyst concentration in the reaction mixture
(Figure 4).
24
Figure 3. Study of degradation rate of PABA under different
experimental conditions.
Figure 4. Degradation percentage of PABA with different catalyst
loading.
25
Under increasing the catalyst loading the degradation rate increases until a
threshold is reached (Figure 4). This occurred because the degradation rate increased
with increasing catalyst loading due to more catalyst surface is available to react with the
pollutant. Once the threshold is reached, the degradation rate decreased due possibly
to the fact that particles of the catalyst are interacting with themselves and more
molecules of PABA are still present without reacting. Also, increasing the concentration
of catalyst could lead to an increment in turbidity that can produce dispersion in the
incident radiation.
Figure 5. UV-Vis spectroscopy results corresponding to the
photocatalytic degradation of PABA using 1.0 g L-1 of TiO2 NWS as a
function of time.
Higher catalytic activity occurred during the first 30 minutes of reaction and after
that the catalysis occurred at a slower but constant pace. At 180 minutes the
absorbance of PABA was much smaller which means that an effective degradation
occurred in a relatively short time in comparison with other similar researches (Figure 5).
It is expected that by increasing the initial pH of the reaction mixture the photocatalytic
degradation increase as reported in previous researches (Mao et al. 2011, Zhou et al.
2013) since the pKa values of PABA are high.
Conclusions
TiO2 nanowires were successfully synthesized and characterized showing high
surface areas. We demonstrated that photocatalytic degradation of PABA proceed in a
26
relatively short period of time. However, further studies are required to better
understand this catalytic process and to identify the reaction by-products.
Acknowledgements
The authors appreciate and want to thank the Puerto Rico Energy Center
(PREC) for the use of its facilities and the Autonomous University of Madrid (Spain) for
XRD and BET analyses. Financial support from US Department of Energy through the
Massie Chair project at University of Turabo is gratefully acknowledged.
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28
BBFuels of Puerto Rico, LLC: A Sustainable Industrial Model for Bioethanol
Production in Puerto Rico
Lugo-Vega J., Nina-Espinosa JL.
BBFuels of Puerto Rico,LLC, Carolina, Puerto Rico
[email protected]
Abstract: BBFuels de Puerto Rico, LLC is a green company that proposes a novel approach to
biomass conversion to energy that reduces the overall process complexity required to produce
ethanol by means of wet water hyacinth of Puerto Rico (Eichhornia crassipes). The problems
that this project solves are the lack of E85 supply for owners of Flex Fuel Vehicles (FFV) and the
overpopulation of hyacinths. Due to hyacinths high lignocelluloses content they can be
considered a promising substrate for the production of bioethanol. For that reason, the
development of ethanol from water hyacinth of Puerto Rico is the innovation offered by this
proposal. Water Hyacinth has an extremely rapid growth rate that clogs rivers and prevents
navigation due to a perfect environment: the tropics. It could be useful as a source of biomass
because of its abundance and feasible cultivation. The impact that this innovation could have
over society consists of improving the quality of life and the environment while providing an
alternative fuel that is less pollutant at a lower cost than fossil fuels. This innovation would
provide E85 ethanol for Flex Fuel Vehicles ’s being acquired despite the lack of E85 in the Puerto
Rican market. In addition, production of ethanol 100 will satisfy other unattended markets such
as Universities, Hospitals or local and federal emergency agencies. The bioethanol from water
hyacinth and anaerobic bacteria has a significant reduction in the cost per gallon of ethanol,
(estimated 64%) due to use of wet biomass instead of typical dry biomass from water hyacinths.
The production of ethanol in Puerto Rico will provide a real option to flex fuel vehicles owners and
has a potential commercial value since the amount of such vehicles being produced and acquired
is increasing as a result of federal and local incentives.
Keywords: water hyacinth, ethanol, E85, FFV.
BB Fuels of Puerto Rico, LLC; Un Model Industrial para la producción de bioetanol
en Puerto Rico
Resumen: BBFuels de Puerto Rico, LLC es una compañía eco-amigable que propone un nuevo
enfoque para la conversión de biomasa a energía reduciendo la complejidad total del proceso
necesario para producir etanol usando el jacinto de agua de Puerto Rico (Eichornia crassipes).
Los problemas que este proyecto resuelve son la carencia de suministro de E85 para los
propietarios de vehículos de combustión flexible, y la sobrepoblación de jacinto de agua. Debido
a que los jacintos tienen un alto contenido de lignocelulosas se pueden considerar como un
sustrato promisorio para la producción de bioetanol. Por esta razón, la síntesis de etanol a partir
del jacinto de agua es lo innovación ofrecida en esta propuesta. El jacinto de agua tiene una
tasa de crecimiento muy rápida resultando en taponamiento de ríos y evitando la navegación
debido al clima perfecto: los trópicos. Puede ser útil como fuente de biomasa debido a su
abundancia y fácil cultivo. El impacto que esta innovación tiene sobre la sociedad consiste en
mejorar la calidad de vida y del medio ambiente a la vez que provee un combustible alternativo
que contamina menos y cuesta menos que los combustibles fósiles. Esta innovación proveería
el etanol E85 para vehículos de combustión flexible que se están comprando a pesar de la
carencia de E85 en Puerto Rico. Además, la producción de etanol 100 satisfacería otros
mercados desatendidos como universidades, hospitales o agencias federales de emergencia. El
bioetanol obtenido del jacinto de agua y las bacterias tiene una reducción significativa del costo
por galón de etanol (estimada en 64%) debido al uso de biomasa húmeda, en vez de la típica
biomasa seca. La producción de etanol en Puerto Rico proveería una opción real para los
dueños de vehículos de combustión flexible y tiene potencial para valor comercial debido a que
29
la cantidad de estos vehículos está aumentando como resultado de incentivos locales y
federales.
Palabras claves: Jacinto de agua, etanol. E85, FFV
Introduction
BBFuels of PR, LLC was born from the former Boriken Bio Fuels Corp. (BBF
Corp.), when one of the partners won a business plan writing competition called: “La
llave para tu negocio” held in 2005, by Metropolitan University of Puerto Rico (UMET).
By means of a proposal submitted to NSF, UMET’s Ecoenterprise competition enables a
research of new entrepreneurs for green business in an incubator system, with a
collaboration of the four Technology Innovation Regions in Puerto Rico. In 2010, Mr.
Johnny Lugo Vega and Mr. Jorge L. Nina Espinosa, representing BBF Corp. were one of
the winners of Ecoenterprise competititon, receiving $20,000.00 to start a green idea for
research and development. At the beginning of 2011, BBFuels of Puerto Rico, LLC
emerged to continue the lead path for waste biomass bioethanol research in Puerto
Rico. BBFuels of PR, with Biotechnology Development and Training Complex (BDTC),
in Mayaguez, Puerto Rico, has carried out experimental trials in a new fermentation
process in order to submit this proposal. These are three of the critical problems of the
Island of Puerto Rico: 1. waste problem, 2. water quality problem because of aggressive
plant (water hyacinth), 3. fossil fuel dependency and greenhouse effect.
The research innovation proposed consists of the study of a tropical endemic
bacteria population from three different, non-food waste biomass raw materials, then
apply a generation fermentation process for the future conversion into ethanol.
This innovation is being proposed in order to: 1. Reduce the solid waste problem
by capturing biomass (over 30% of landfill waste that consists of biomass), 2. Improve
the quality of water by removing an aggressive plant which is one of the sources of water
quality problems in Puerto Rico (water hyacinth), 3. Offer an alternative product that is
less pollutant than fossil fuels at a lower cost.
The waste problem is of large proportions. According to the Solid Waste
Management Authority of Puerto Rico, water hyacinths, grass biomass, paper/waste
fruits and sugar food waste mixed raw materials, represent 35% of Puerto Rico’s total
landfill waste (4M Tons/Y). Water hyacinths negatively affect the water quality, and
fossil fuel is costly. Solid waste landfills are closing by regulations of USEPA, creating a
solid waste disposal crisis starting in 2011. (ADS 2011). According to ADS data, the
average solid waste generation in Puerto Rico is 4MT/Year. Market integration with
biomass ethanol production will create an open market in order to deal with solid waste
reduction.
The impact that this innovation could have over society consists of improving the
quality of life and environment while providing an alternative product that is less pollutant
and at a lower cost than fossil fuels. This innovation would provide E85 ethanol for flex
fuel vehicles which are being acquired despite there not being availability of E85 in the
Puerto Rican market. It would promote the acquisition of such vehicles in order to have
a lower cost alternative. Employments throughout its different phases would be created
in order to research, distribute, market, etc.
At the present time the direct solution to the problem presented by the Federal
and Local government consists of legislation requiring and providing tax incentives for
the creation and acquisition of hybrid and flex fuel vehicles. No ethanol is being
30
provided at the present time for such, nor being developed in Puerto Rico.
Objectives
The objectives of BBF are focused in modeling a sustainable industry in Puerto
Rico by means of bioethanol conversion of Water Hyacinths (Eichhornia crassipes). The
main objective is to discover how an anaerobic fermentation process will lead towards
the best conversion of water hyacinth into bioethanol, biogas and bio-products. The
development of ethanol from water hyacinth of Puerto Rico will allow us to work in the
future with other types of biomass (grass, paper, etc.) and the correspondent bacteria
population.
Materials, Method and Procedure
Pretreatment of water hyacinth
The starting protocol consists of a pretreated two cycles path of steam explosion
and hot water hydrolysis for cellulose/hemicellulose breakdown of Puerto Rico Water
Hyacinth (Eichhornia crassipes). Then, an anaerobic fermentation with a special
bacteria X will be performed in order to obtain the best glucose/ethanol content by g/L
value, measured by YSI 2700 Select. Instead of using the regular hydrolysis protocol
with sulfuric acid, a modified auto-hydrolysis pretreatment followed with two round steam
explosion/hot water pre-treatment will be used. This method will avoid the use of strong
acids and will reduce the amount of chemical waste. Water under high pressure can
penetrate into the biomass, hydrate cellulose, and remove hemicelluloses and part
lignin.
Bacteria Growth Procedure
Bacteria X was seeded in culture in a 500mL flask (Sartorius) containing 200 mL
of maintenance media at 55˚C for 48hrs. Following preparation, 200 ml of the media
was added into 500 ml SCHOTT - Duran GL45 Premium Glass Bottle, and autoclaved
for 30 minutes at 20 psi (121 °C). After cooling to 55˚C, the bottles were flushed with
instrument grade N2 until media is fully reduced (color will change from red to amber)
and then with CO2 for 10 minutes to obtain a concentration of approximately 10% vol /
vol.
The bottles were inoculated with 10% vol/vol of a 3 day culture. Maintenance
cultures were grown unshaken at 55 °C by placing the bottles in an incubator (Certomat
BS-1, Sartorius).
Cultures were passed every 3 days. A series of 2L batch
fermentations will be done using the same media as a nutrient source.
Fermentation
Biostat A plus bioreactor was used for the fermentation of the bacteria. All media
reagents will be prepared in a 5L vessel and autoclaved for 30 minutes at 20 psi. After
calibration of a pH probe will be sterilized inside the vessel while dissolving oxygen
probe will be sterilized separately to obtain the 100% Oxygen calibration prior of its
insertion onto the bioreactor vessel. Finally, an inoculation with a 10% v/v solution was
performed, maintained unshaken at 55 °C for 3 days. Optimal conditions for bacteria x
31
were determined as well as the, optimal growth process will be adjusted for the use of
water hyacinths as carbon source to obtain, as primary fermentation byproduct ethanol.
For this purpose the procedure will remain the same except for the use of the hyacinths
in substitution of the glucose.
Preliminary results
Three (3) consecutive trials showed that a low cost procedure for the digestion of
water hyacinth mother liquor (WHML) can be achieved in a short period with low
temperature. The preliminary results obtained during summer of 2011, showed a lab’s
scale growth rate of bacteria x in a very simple ambient and low temperature conditions.
(Figure 1 and 2). After 10 days of trials, water hyacinth’s mother liquor was reacted with
bacteria x medium for glucose/mass behavior. Preliminary results showed that it can be
possible to obtain glucose/acetic acid rate in anaerobic climate, latter on convert it to
ethanol by a wet chemical procedure. Future outlooks over bacteria x and water
hyacinths raw biomass are under diverse anaerobic testing in order to obtain an
optimum glucose content.
Figure 1. WH pretreatment at BDTC facilities.
0.9
0.5
[Glucose] (g/L)
0.4
0.7
0.3
0.2
Cells (OD
600nm)
0.1
Glucose
0.5
0.3
04, 0
0
1
2
3
4
Time (days)
32
Figure 2. Glucose comsumtiona and bateria X
growth rate.
BBFuels of Puerto Rico, LLC Comercialization plan
BBFuels of Puerto Rico, LLC (BBF) consist in three main components (Figure 3).
The immediately market: E100. Ethanol in Puerto Rico has a great potential market due
to his geographical features. Even when we think in available space for the production of
first generation biomass ethanol or different sources, (raw sugar cane, corn and Palm
oil) Water hyacinths biomass has never been tested, neither in the Caribbean Basin. Our
proposed project has a direct market with the production of pure 100 % ethanol (E100)
and byproduct to satisfy the demand from institutions such as universities, hospitals and
cleaning/sanitization industries. Secondly, E100 could be blended with gasoline in
different percent rates: E10%:90% gasoline, E20%; 80% gasoline, E40%: 60% gasoline
and finally E85%: 15% gasoline to achieve the target market: 85% ethanol production
and flex fuel vehicles. This last blend, E85 represents another direct market due to the
flex vehicles market. There is no availability of E85 or other blends in Puerto Rico for
FFV.
Figure 3. BBFuels of PR, LLC conceptual
components and process architecture
Market diversification will be focused on Biogas, Organic Fertilizers and Furniture
business. The BBF’s process for bioethanol production of biomass’s water hyacinths
includes several materials, from raw material to final residues that will be recovered for
his commercialization. Biogas from anaerobic fermentation process such as CO 2 and
Methane have a special market which is non-attended at this moment in Puerto Rico
while open a stimulus to the industrial sector to use biogas a low cost generated by a
sustainable way. Calcium Phosphate in the form of gypsum (clay) could be reused to
improve quality in fertilizers for damp places. On the other hand, water hyacinth’s leaves
and stem residues could be used as a great nitrogen source for organic fertilizers, while
lignin and raw steam residues will be transformed into furniture.
References Cited
33
[ADS] Puerto Rico Solid Waste Authority. 2011. “Annual Report on Solid Waste
Generation in Puerto Rico”..http://www.ads.gobierno.pr, 3/01/2007. Accessed on
12/08/2011.
Aswathy US, Sukumaran RK, Devi GL. 2010. “Bio-ethanol from water hyacinth biomass:
An evaluation of enzymatic saccharification strategy”. Bioresource Technology
10(1):925–930.
Isarankura-Na-Ayudhya C, Tantimongoclwat T, Kongpanpee T, Prabkate P,
Prachayasittikul V. 2007. “Appropriate Technology for the Bioconversion of Water
Hyacinth (Eichhornia crassipes) to Liquid Ethanol: Future Prospects for
Community Strengthening and Sustainable Development”. EXCLI Journal 6: 167176.
Ogawa Masami GO, Usui IY, Urano N. 2008. “Ethanol production from the water
hyacinth Eichhornia crassipes by yeast isolated from various hydrospheres”.
African Journal of Microbiology Research 2 (5): 110-113.
A-1
Ambientis 2014. Appendices One and Two.
Appendix One
Abstracts from the Ambientis Symposium held 7
September 2012
____________________________________________________
SYNTHESIS AND CHARACTERIZATION OF VERTICALLY ALIGNED SINGLEWALLED CARBON NANOTUBES TO BE USED IN THE DEVELOPMENT OF NEW
RADIATION SENSORS
G C Andino, A Cartagena, J Ducongé, A García, M Cotto and F Márquez
Nanomaterials Research Group-NRG, School of Science and Technology, Universidad
del Turabo, 00778PR, USA
[email protected] ; [email protected]
Since the landmark paper of S Iijima on carbon nanotubes (CNTs), there have been
relevant research efforts on this new material. This great interest has been due to their
unique mechanical, electronic and chemical properties and their potential applications as
field emitters, development of new composites and conductive coatings, in energy
storage, thermal materials, catalyst supports and many other applications. The growth of
aligned CNTs is paramount for many of these applications are fully exploited. That is the
reason why during the last few years many research groups have been focused on the
design of new methods for controlling the CNT morphology. At present, two different
fabrication methods for obtaining vertically aligned CNTs are normally used: (i) the direct
growth by thermal catalytic chemical vapor deposition (CCVD) and (ii) the screenprinting technology from a paste mixture of CNTs. Nevertheless, these approaches have
clear limitations and, in the case of the screen-printing process, the use of organic
additives is a serious problem for their application in opto-electronic technology. In this
research we report a method for the synthesis of vertically aligned SWCNTs, based on
the use of a mixture of CoII and MoII salts as catalyst precursor. In this case, the growth
is achieved by CVD using alcohol as carbon source. The characterization of the
synthesized material has been carried out by scanning electron microscopy (SEM),
revealing that vertically aligned SWNTs (VA-SWNTs) are agglomerated in different cross
sections of the silicon wafers. This material will be the basis for the design and
development of new sensors for ionizing radiation.
GENETIC BIODIVERSITY OF MYCOPLASMA SPECIES IN NEOTROPICAL
ENVIRONMENTS
LV Arroyo-Cruz; JR Pérez-Jiménez
School of Science and Technology, Universidad del Turabo
[email protected]
The genus Mycoplasma has high impact on public health, veterinary, biotechnology, and
environment due to versatile life style that induces serious damage and disease. This
peculiar group is seen as emerging infectious agents in humans, animals and cultured
eukaryotic tissues. Interestingly, new habitats are being reported recently in biofilms and
corals. Current molecular markers developed for clinical applications are anticipated to
be limited on detecting diversity of the genus Mycoplasma in the natural environment,
specially the neotropics. In the past, the biomarkers design was based on strains of
A-2
specific interest: public health, veterinary medicine, and biotechnology. Strategies to
detect mycoplasmas should be improved in sensitivity and specificity supported on
genomics progress experienced in recent years. But now we can exploit the emerging
knowledge on the genetics of mycoplasmas to propose new and or more extensive
application tools. This way, we can evaluate and extend these biomarkers to new
environmental (nature, veterinary) and artificial (clinical, industrial) scenarios. The goal of
this dissertation is to assess genetic biodiversity of Mycoplasma species in a neotropical
environment applying a novel biomarker for PCR-based detection. The specific
objectives include (1) to evaluate the efficiency of prior PCR primers designed for
Mycoplasma detection; (2) to design and validate a new PCR primer for detect
Mycoplasma species; and 3) to apply the new PCR primer for Mycoplasma detection in
diverse neotropical environment settings. Recently, GenBank hosts 38 complete
genomes sequenced among 464 mycoplasmas species recognized (8.2%), 2) 121 16S
rRNA genes (1.2%) among 10,458 nucleotides deposited, and only 2.5% (3/121) of the
sequenced genomes are represented among the pool of 16S rDNA sequences.
Therefore, the level of high quality genomic information more recently available,
represented on completely sequenced genomes, provides an opportunity to increase the
resolution of current molecular tools for the detection of Mycoplasmas.
NEW TOOLS FOR OLD PROBLEMS: MICROBIAL DEGRADATION OF ALIPHATIC
ALKANES FOR THE RESTORATION OF CONTAMINATED SOIL
Y Bernier1, 5; SA Cantrell2, 3; JR Pérez-Jiménez2, 4, 5
1
Environmental Science Graduate Program; 2Department of Biology; 3Doctoral Study
Center; 4Interdisciplinary Research Institute; 5Puerto Rico Institute for Microbial Ecology
Research, Universidad del Turabo, Gurabo, Puerto Rico, USA
[email protected]
Enormous quantities of organic compounds are released into the environment each year
as a result of human activities. The fate of these pollutants as potential groundwater
contaminants and their subsequent toxicological impact on humans and other living
receptors is an important issue. Our objective is to isolate alkane-degrading bacteria
under various pollution levels in Puerto Rico. Samples were collected from soil subjected
to punctual spill (Bayamón river), minor (mechanic garage), major chronically discharge
(Caño Martín Peña and Thermoelectric plant) and with minor anthropogenic activities (El
Yunque Rain Forest and Microbial Mats). Native microbiota was cultivated, as
consortium, on rich media for further studies. Alkane-degrading bacteria were isolated
from the original sample by aerobic cultivation on mineral media supplemented with
specific alkane (hexane, isooctane or hexadecane) as sole carbon source. Bacterial
prospects for aliphatic alkane degradation were subjected to 16S rDNA sequencing and
alkane degradation preference test. Sixty aliphatic alkane-degradation prospects had
been isolated so far from the six study sites. Most preferred hexadecane over hexane or
isooctane. Closest homology found to Pseudomonas, Aeromonas, Klebsiella,
Acinetobacter, Bacillus and Microbacterium. Eight coliform strains (E. coli and Klebsiella)
degraded the three alkanes: hexane, isooctane and hexadecane. Soil sample from a
mechanical garage provide the most diverse group of alkane-degrading isolates (5
genera). Bioremediation need to operate within a pH range suitable for wildlife to
survive. Tolerance to pH (5.0 to 8.5) was assayed for an alkane-degrading strain
representing each studied ecosystem in Puerto Rico. Microbial growth was estimated by
optical density (600 nm) for liquid cultures enriched with hexadecane (µl/ml); incubated
for 56 hours at 27 °C and 180 rpm. Six strains examined, representing each sampling
site, grew degrading hexadecane at pH 5.0, 7.0 and 8.5. Some strains prefer some pH
values while others tended to have a constant pattern. A collection of alkane-degrading
A-3
bacteria with defined preferences for specific alkanes and environmental conditions has
been established. Further studies will elaborate on degradation rates and catabolic
genes.
GROWTH AND CHARACTERIZATION OF CRYSTALLINE FE2O3 NANOWIRES BY
OXIDATION OF IRON SUBSTRATES
C Bonilla1, A García1, J Ducongé1, T Campo2, E Elizalde2, C Morant2, F Márquez1
1
School of Science and Technology, University of Turabo, 00778PR, USA
2
Departamento de Física Aplicada C-XII, Universidad Autónoma de Madrid, 28049
Madrid, Spain
[email protected]
During the last decade, nanosized iron oxide has attracted significant attention because
of their potential applications and interesting properties. Besides of technologically
based applications, (i.e. gas sensors), these materials have interesting properties that
differ from those with larger dimensions. Some nanomaterials of iron oxide phases have
found their prospective utilization in various fields in medicine like materials for drugs
delivery. In this research, highly crystalline iron oxide nanowires have been successfully
synthesized by a simple catalyst-free growth procedure. In a typical synthesis, iron oxide
nanowires were grown by heating pure iron substrates inside a quartz tube furnace at
different temperatures, ranging from 400 ºC to 600 ºC, in vacuum or oxidative/reductive
conditions. The morphology and structural characterization of the iron oxide nanowires
have been studied by Field Emission Scanning Electron Microscopy (FESEM), X-ray
diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). XRD measurements of
nanowires synthesized in oxidative environments indicated the presence of a highly
crystalline mixture of magnetite (Fe3O4) and hematite (α-Fe2O3). Preliminary results have
also indicated that the magnetite phase (Fe3O4) can be importantly increased under
vacuum or in presence of reductive environments with respect to the hematite phase.
THE ROLE OF ARTIBEUS JAMAICENSIS AND BRACHYPHYLLA CAVERNARUM
INTHE DISPERSAL OF THEENDANGERED STHALIA MONOSPERMA IN
PUERTO RICO
Erik Calderon1, Wilkins Otero1 Armando Rodríguez-Durán1, Elson Viruet2, and Eugenio
Santiago Valentín2
1
Universidad Interamericana, Recinto de Bayamón, Bayamón, PR. 2Jardin Botánico,
Universidad de Puerto Rico, Rio Piedras, PR.
[email protected]
We present data on food choice experiments of the Phyllostomid bats Artibeus
jamaicensis and Brachyphylla cavernarum, as related to the endangered tree Stahlia
monosperma. The distribution of S monosperma, an endangered tree for which no
dispersal vector is known, is restricted to a few locations around the island of Puerto
Rico and eastern Hispaniola, Greater Antilles. It has been speculated that bats or land
crabs might be the dispersal vector, that the extinct echimid rodents could have been the
dispersal vector, or that the tree is thalassochorous rather than zoochorous. We
released bats in a flight cage, where they were presented with two food choices, with the
purpose of assessing their role in the dispersal of S monosperma. We also made nightly
observations of the trees to determine whether bats in the wild were attracted to the
fruits. Artibeus jamaicensis and B cavernarum commonly carry fruits about the size or
larger than those of S monosperma. Our results reveal that when presented only with S
monosperma, bats will feed on the fruits. When presented with a choice, B cavernarum
A-4
will select and carry fruits of S monosperma occasionally, while A jamaicensis explored
the plates briefly before moving to the other choice offered, or consumed the fruits in the
plate rarely carrying them. There was considerable bat activity around the S
monosperma trees and, on one occasion, seeds were found under a tree at least 15 m
from where the fruits could have been obtained. The fact that some bats will carry and
feed on the fruits of S monosperma has important implications for the conservation of
this endangered species, although it should be noted that these fruits appear to be at the
bottom of the dietary preferences of bats.
MODELO SISTEMODINÁMICO PARA EL ANÁLISIS DEL PROCESO DE
FITORREMEDIACIÓN
RR Canales-Pastrana1,2
1
Escuela de Ciencias y Tecnología, Universidad del Turabo
2
Departamento de Ciencias Naturales y Matemáticas, Universidad Interamericana de
Puerto Rico Recinto de Bayamón
[email protected]
El manejo ambiental como ciencia interdisciplinaria tiene el mandato de evaluar las
diferentes interacciones que puedan afectar el sistema bajo estudio. La contaminación
por metales pesados es una de las mayores preocupaciones de la comunidad científica,
debido a su toxicidad y la capacidad de bioacumularse. Las técnicas tradicionales cómo:
excavación, tratamiento químico y encapsulamiento, son consideradas ambientalmente
invasivas y costosas. Una técnica alternativa es la fitorremediación, la cual se basa en
el uso de plantas para la extracción del contaminante. La fitorremediación es una
técnica costo-eficiente y prometedora pero, a su vez tiene varias interrogantes: ¿Cuál es
la mejor planta para atender cada contaminante? ¿Cuál sería la rapidez del
contaminante a través de la planta? Mediante un acercamiento sistemodinámico se ha
desarrollado un modelo dinámico para poder evaluar la técnica de fitorremediación. El
Modelo Dinámico de Fitorremediación (MDF), se fundamenta en la estructura fisiología
de la planta y la interacción entre el suelo y el aire, en función del tiempo. El mismo
provee un acercamiento comprensivo que puede ser explicado de forma esquemática o
teórica mediante las ecuaciones diferenciales que lo describen. Luego de la
construcción de MDF, se procedió a la calibración utilizando datos publicados. MDF
predijo más del 95% de los datos experimentales y proveyó las razones de flujo del
contaminante en la planta.
AMMONIA-OXIDIZING ARCHAEA COMMUNITIES AT EL YUNQUE RAIN FOREST IN
PUERTO RICO
A Carazo-Carrión1, 3; JR Pérez-Jiménez1, 2, 3
1
School of Science and Technology of Biology, 2Interdisciplinary Research Institute;
3
Puerto Rico Institute for Microbial Ecology Research, Universidad del Turabo, Gurabo,
Puerto Rico, USA
[email protected]
Archaea has a key role in ammonia oxidation reactions in the first step of Nitrification.
The tropical rain forest El Yunque has a gradient of climate that changes and extends
through four life zones (subtropical moist forest to lower montane forest): Tabonuco,
Colorado, Elfin, and Palm. We hypothesize that a diverse community of ammoniaoxidizing archaea (AOA) prevails across the life zones of El Yunque. Our objective is to
A-5
ascertain the richness and distribution of AOA communities along microclimates
throughout the elevation gradient. Genomic DNA was extracted from soil samples
collected in June 2005. AOA communities were characterized with terminal restriction
fragment length polymorphisms of the archaeal ammonia-onooxygenase gene (archamoA) amplified from soil samples. A total of 249 phylotypes (TRF) were detected
(representing 224 different TRF’s). TRF abundance ranged among forest from 191
(palm), 31 (Colorado), 20 (Tabonuco), and 5 (Elfin). A total of 209 phylotypes appeared
once in the samples, representing 93% of the communities. Similarity analysis, based on
the Sorensen’s index showed great diversity (ranging from 0-96%) without geographical
clustering. The TRFLP analysis presented a broad diversity of archaeal communities
through the microclimate of El Yunque. According to the Sorensen's similarity index,
diversity appears to be driven by the microclimate of each forest. That suggests that the
AOA communities found in the tropical forest take part of a specific microclimate that
provides the nutrients they need in a more convenient form. By comparing microbial
diversity along this gradient, we contribute to understand general properties that underlie
the dynamics of ecosystems.
CALIDAD DEL AGUA: IMPLICACIONES SOCIALES Y POSIBLES EFECTOS A LA
SALUD
J Cartagena-Díaz; NE Lebrón-López; J Arce-Nazario
Universidad de Puerto Rico en Cayey
[email protected]
La calidad de agua varía por región, comunidades y dentro del hogar. Este estudio
analiza como distintas variables sociales y ambientales pueden estar afectando la
calidad del agua en los hogares de Puerto Rico y la salud de sus consumidores. Se
llevaron a cabo más de 250 entrevistas en los municipios de Cayey, Caguas y Comerío,
en las cuales se hicieron preguntas demográficas, de salud y la percepción de la calidad
del agua. Durante esta investigación, se estudiaron dos fuentes de servicio de agua:
PRASA y Non-PRASA. PRASA se refiere al servicio que se recibe de la Autoridad de
Acueductos y Alcantarillados (AAA), mientras que el conjunto de Non-PRASA se refiere
a todos los sistemas que no sean de la AAA. Luego de cada entrevista se tomó una
muestra de agua de la pluma. Se tomó una muestra de agua adicional si el entrevistado
tenía un sistema de tratamiento de agua como, por ejemplo, filtro de fregadero o un
sistema de osmosis reversa. En el hogar se medía el nivel del cloro libre y total usando
un colorímetro manual. Las muestras de 100mL de agua se analizaban dentro de 24
horas para presencia de coliformes totales (CT) y coliformes fecales (CF) utilizando el
método de Colilert. Se logró analizar el agua en un total de 278 casas (125 del sistema
Non-PRASA y 152 del sistema PRASA). Un 74% de las casas entrevistadas en
comunidades Non-PRASA tuvieron presencia de CT, en contraste con un 17% en
comunidades PRASA. La presencia de CT estaba relacionada con el nivel de cloro libre
en el agua. Con la excepción de aquellas casas que tenían algún sistema de filtrado en
la toma principal, todas las casas en sistemas PRASA tenían cloro libre en el agua,
encontrándose dentro de los estándares de la EPA. El 49% de las muestras obtenidas
de sistemas de tratamiento de agua en el hogar (n=45) tenía presencia de CT. La
presencia de CT y CF en el agua no estaba correlacionada con problemas
gastrointestinales de las personas entrevistadas. Sin embargo, se pudo observar una
tendencia de problemas gastrointestinales en las comunidades que recibían agua del
sistema PRASA en comparación con las comunidades Non-PRASA. Estos resultados
demuestran que muchas casas no están dando el debido mantenimiento a sus equipos
de tratamiento de agua y que la presencia de coliformes no es un buen indicador de
problemas gastrointestinales en las comunidades entrevistadas.
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Lestes PREDATION
Stella Castro
Ciencias Ambientales de la Universidad Metropolitana Recinto Cupey
[email protected]
Zones and may have a large impact on zooplankton communities. I studied sizeselective predation by Lestes (Odonata: Lestidae) I measured strike and capture
efficiency of Lestes feeding on several species of zooplankton which ranged in size from
0.1-11.4 mm. Capture efficiency (83%-99%) was always higher than strike efficiency
(40%-99%). Lestes were more successful feeding on small and slow prey (e.i. small
Scapholeberis) and medium and fast prey (e.i. medium Daphnia). They were least
successful feeding on Chaoborus pupae because of their well-developed escape
response.
SYNTHESIS AND PHOTOCATALYTIC ACTIVITY OF TITANIUM OXIDE NANOWIRES
ON MODEL ORGANIC COMPOUNDS
M Cotto1, T Campo2, E Elizalde2, C Morant2 and F Márquez1
1
School of Science and Technology, Universidad del Turabo, 00778PR, USA
2
Departamento de Física Aplicada, M-12, Universidad Autónoma de Madrid,
Cantoblanco, 28049 Madrid, Spain
[email protected]
Water is an essential resource for humankind to sustain the basic human functions as
health and agriculture and for the integrity of the biomes. According to some authors,
less than a 0.7% of the total of water in the Planet is fresh water and only 0.01% is
accessible to be used. The access to safe water for drinking water and other uses is a
basic right especially in children. Biological and chemical contaminants compromise the
water quality in the world. The degradation of water sources and natural resources is
actually one of the most discussed issues. Organic, inorganic, bionutrients and
microorganism are some of the most common contaminants in water. The textile
industry is one of the most contaminant industries because dyes are nonbiodegradable
compounds. Industrial wastewaters that contain biorefractory compounds are normally
limited to the use of chemical treatments because the chemicals are toxic to the
microorganisms used in the conventional biological treatments. Potential human
exposure to wastewater which contains dyes is a concern because are carcinogenic
compounds, showing high resistance against biological, physical and chemical
reactions. The advanced oxidation processes or AOPs have received great attention
from researchers during the last decades, because these processes can lead to
complete mineralization of organic pollutants. The use of photocatalytic materials is a
common AOPs technique but the use of the photocatalytic nanowires could be a new
option for the degradation of contaminants. One of the possible options is the use of
titanium oxide nanowires as a catalyst for the degradation of organic compounds. In this
research, titanium oxide nanowires (rutile phase) have been synthesized by
hydrothermal method. The nanowires have been characterized using scanning electron
microscopy (SEM), X-ray diffraction (XRD), infrared spectroscopy (FTIR) and UV-vis
spectroscopy. Methyl orange and rhodamine B were used as test molecules and their
photodegradation has been studied by UV-vis and fluorescence spectroscopies and total
organic carbon (TOC) analysis. By using titanium oxide nanowires as catalyst, the
organic pollutants experience a high degradation rate, reaching values between 93.55 %
and 96.44% for methyl orange and rhodamine B, respectively. The mean velocity
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evaluated for this reaction is approximately 10-2 min. The results obtained during this
research demonstrated the efficiency of the process, pointing out to the possible use of
rutile nanowires in advanced oxidation processes.
ESTRATEGIAS DE COMUNICACIÓN AMBIENTAL PARA LAS COMUNIDADES DE
LAS CROABAS
L Crespo- Nazario
Sistema Ana G Méndez, Escuela de Asuntos Ambientales, Universidad Metropolitana
[email protected]
La comunicación ambiental es fundamental para solucionar cualquier situación que
ponga en riesgo la vida del hombre y los recursos naturales. El ser humano construye
su conocimiento a partir de experiencias vividas, donde se le da la oportunidad de
expresar su opinión y llegar a sus propias conclusiones. Esta investigación pretende
establecer estrategias de comunicación utilizando la investigación ambiental luego de
haber realizado de tres procedimientos de orden cualitativo y cuantitativo en el área de
las Croabas. Estos fueron: la observación de la población en el parque pasivo,
evaluación de las querellas ambientales a agencias gubernamentales y un cuestionario
sobre los recursos naturales del área y situaciones ambientales que enfrentan. Los
resultados de las observaciones demostraron que los recursos naturales del área son
sumamente impactados, en la mayoría de los casos por no residentes. Las querellas
ambientales expusieron la falta de conocimiento que existe referente al Departamento
de Recursos Naturales y Ambientales, la Junta de Calidad Ambiental, demostró estar al
día en todo lo relacionado a las disposiciones de contaminantes al agua de los
concesionarios de comida, mientras que el cuestionario definió que los residentes de las
Croabas sí conocen sus recursos naturales y su importancia a pesar de que enfrentan
situaciones que afectan su salud a causa de la contaminación. En conclusión las
estrategias que se establecieron al final del estudio cubren las áreas de la educación,
seguridad, comunicación y legislación ambiental.
FUNGI ENDOPHYTES FROM THE SPATHODEA CAMPUNALATA INVASIVE PLANT
IN PUERTO RICO
J I Cruz Rodríguez1, 3, JR Pérez-Jiménez1, 2, 3
1
School of Science and Technology; 2Interdisciplinary Research Institute; 3Puerto Rico
Institute for Microbial Ecology Research, Universidad del Turabo, Gurabo, Puerto Rico,
USA
[email protected]
The Introduction of the Spathodea campanulata in Puerto Rico took place in the late 20th
century. The tree S campanulata is part of the Bignoniaceae family and ever since it was
introduced it has been occupying unused agriculture areas. Because of its flower the
Tulipán was introduced, and it has been the only specie to regenerate in the fields where
sugarcane grew. After several years, this initial domination decreases, and once the
forest was restored, thanks to bats, birds and other organism, native species return to
undergrowth. Our objective is to determine the diversity of fungal endophytes in
Spathodea campanulata. Bark, flower, and leaves samples were collected from S
campanulata in Puerto Rico. Pieces were cultivated in Malt Extract Broth 0.5X for 7-10
days at room temperature. Bark and flower samples were cultivated in Malt Extract Agar
1.0x for 1 week at room temperature. The fungi that grew the week after was isolated in
Potato Dextrose Agar 1.0x for 1 week. The Leaf was cultivated in Malt Extract Agar 1.0x
for 1 week at room temperature. In the bark six different types of fungi were found,
Penicillium, Cladosporium, Trichoderma, Acremonium, Fusarium and Paecylomyces. In
the flower 3 different types of fungi were found Aureobasidium, Aspergillus and
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Cladosporium. The isolation for leaf samples, DNA extraction and TRFLP from samples
is in progress. A diverse endophytic fungi community was found in the invasive
Spathodea campanulata. The elucidation of endophytic fungi in invasive plants provides
a source for biotechnological applications and ecological understanding.
FAUNA DIVERSITY IN THE HABITATS SURROUNDING THE ARECIBO
OBSERVATORY IN THE NORTHERN KARST OF PUERTO RICO
Nohelysmarie Delgado-Olivo1 , Maria F Barberena-Arias1
1
School of Sciences and Technology, Universidad del Turabo
[email protected]
The karst region in Puerto Rico covers 27.5% of the terrestrial surface and is divided in
North and South areas. This region harbors native and endemic animal species, some of
them being threatened or in critical status. Nevertheless, few studies have addressed
the biodiversity status of the karst fauna. As a consequence, we studied the forest
habitats surrounding the Arecibo Observatory in the northern karst with the objective to
build an inventory of the fauna diversity associated to these habitats. For this, several
field trips were made to the Arecibo Observatory lands to visit four areas: vegetation
under the reflector, forest, vegetation surrounding the photometer and the staging area.
In each area we registered observed organisms, and we used a butterfly net, we took a
soil sample and we scout the area in active research to collect animals. Collected
organisms were placed in labeled vials with alcohol. We found a total of 168 individuals,
41 were present under the reflector, 50 in the forest, 74 in the photometer and 3 in the
staging area. These individuals represented a total of 13 orders, 8 were present under
the reflector, 11 in the forest, 10 in the photometer and 2 in the staging area. Isopoda
only occurred in the forest, Diplopoda was unique to the vegetation under the reflector,
Phasmatodea to the vegetation surrounding the photometer. These data suggest that
animals associated to these areas include unique and common organisms. This is an
ongoing project, and additional data is being collected.
LEAF LITTER FUNGAL BIOPROSPECTING FOR BIOFUEL APPLICATION
Caroline Delgado, Coral Rivera and Sharon A Cantrell,
School of Science and Technology, Universidad del Turabo, Gurabo, PR
[email protected]
Leaf litter is the main component of the plant biomass that reaches the forest floor and
due to the process of decomposition nutrients are release to the soil, which then are
recycle. Leaf litter decomposition is a successional enzymatic process, with cellulose
important in the early stages followed by later activation of peroxidase and phenol
oxidase, which are required for lignin degradation. The specific objectives are to isolate
fungi from leaf litter using general and specific culture media, and conduct cellulose,
lignin and xylan degradation assays. The methodology consisted of taking leaf litter from
four forest types at El Yunque National Forest (Tabonuco, Palm, Palo Colorado and
Elfin). The particle filtration technique was used to isolate fungi using different general
growth media (50% PDA, 50% MEA, 50% MEA + 5% NaCl). Fungal isolates were
purified and screen for potential cellulase, xylanase, peroxidase and phenol activity
using cellulose agar, remezol blue agar (for lignin) and xylan agar. Isolates were
identified using morphological and molecular characters. We have isolated 127 potential
fungal bioprospects. So far, we have tested 57 isolates for cellulose, lignin and xylan
degradation. All these isolates have been able to grow in all tested media. Of this 57
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isolates, none have shown lignin degradation, 25% can degrade cellulose and 49% can
degrade xylan. These results were expected because xylan is easier to degrade than
cellulose and lignin. We expected to obtain multiple isolates of fungi that can be used to
further explore their potential used in biofuel production.
BACTERIAL ENDOPHYTIC DIVERSITY IN EXOTIC FLOWERS OF THE INVASIVE
PLANT SPATHODEA CAMPANULATA IN PUERTO RICO
XE Espada-Fuentes1, 3, JR Pérez-Jiménez1, 2, 3
1
School of Science and Technology; 2Interdisciplinary Research Institute; 3Puerto Rico
Institute for Microbial Ecology Research, Universidad del Turabo, Gurabo, Puerto Rico,
USA
[email protected]
Spathodea campanulata exotic species was introduced more than 5 decades ago as an
ornamental plant primarily for its colorful flower in Puerto Rico. The African tulip (S
campanulata) recognized as secondary forest species, as it tends to predominate in the
mountains and valleys that in past decades were farmland. Restore native species
previously unable to germinate creating suitable and stable conditions for their livelihood.
This phenomenon is due to the dynamic microbial ecosystem. Our goal is to determine
the native diversity of endophytes in S campanulata. Taking samples of the species
important as the flower, leaf and bark. The pieces were cultured in Tryptic Soy Broth for
48 hours 0.5X at room temperature. Mixing the cultures is subjected to a restriction
polymorphism terminal fragment length 16S rDNA-TRFLP and 16S rDNA sequencing of
the isolated strains. With the results obtained from the native microbial, it has been
determined the copious bacterial community in the first analysis were found in the cortex
with 157 phylotypes, followed by the flower and leaf with 51 to 21. At its second and
most recent analysis found curiously more phylotypes in the prime of 46, leaf 53 and
cortex 27. Detailed characterization is in progress for additional insulation. Interestingly a
different endophytic bacterial community was found in the exotic flower of S
campanulata. The elucidation of endophytic bacteria in invasive plants is a source for
biotechnological and ecological understanding.
PHYCOLOGICAL CULTURE OPTIMIZATION FOR THE PRODUCTION OF FUEL
OILS
1, 3
XE Espada-Fuentes ; JG García-Díaz1, 3; JR Pérez-Jiménez1, 2, 3
1
3
Puerto Rico, USA
[email protected]
Global warming has become one of the greatest threats to environmental stability in our
world today. The emissions of greenhouse gases (GHG) produced with the burning of
fossil fuels is thought to be the major cause of atmospheric pollution and climate change,
therefore scientist are searching for new cleaner alternatives to the use of fossil fuels as
an energy source. Algae are being proposed as an ideal F2 generation biofuel source
due to characteristics that could potentially make them more efficient than any other type
of renewable biofuel source. They are carbon neutral, they require less land mass to
grow, they have high growth rates; e.g., doubling in 24h, and produce 15-300 times
more oil for biodiesel production than traditional crops on an area basis. Our objective is
to optimize conditions for lipid production within microalgae in order to achieve high
density and high productivity. Certain growth parameters are used as parameters that
can potentially directly affect lipid production. The effects of light intensity variations,
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different organic carbon sources (including nitrogen and glucose) and pH balance were
investigated. Algae were cultivated in 125 mL elermeyer flask and four different species
were used, Nannocloropsis oculata, Chlorella vulgaris, Isocrysis galbana, and
Botryococcus braunii. Each species was chosen based on their high lipid content under
normal growth conditions. Optical density measurements were taken with the Eppendorf
BioPhotometer plusTM three times per day to record density variations. Growth rate was
increased in the algae Botryococcus braunii when supplemented by an initial glucose
concentration of 2.5 g L-1, adversely the effect of this glucose concentration on
Nannocloropsis oculata was a longer lag phase, thus the adequate amount of the
specific carbon source that is required in order to achieve optimization varies with
species. In the species Chlorella vulgaris and Isocrysis galabana changes in light
exposure, intensity, and temperature induced faster growth rates in both species.
SYNTHESIS AND CHARACTERIZATION OF HOLLOW MAGNETITE
MICROSPHERES
Miriam R Espino, María C Cotto, José Ducongé and Francisco Márquez
Nanomaterials Research Group-NRG, School of Science and Technology, University of
Turabo, 00778PR, USA.
[email protected]
During the last few years, magnetic particles have attracted a great attention due to their
interesting applications in different fields, including catalysis, information storage,
optoelectronics, biomedical applications, bioseparation, magnetic resonance imaging
and targeted drug. These materials are characterized by having a large surface area, a
very low density and also a strong magnetic response that make them interesting
candidates to be used as drug carriers. The internal hollow spaces may be used as
hosts for the encapsulation of guest molecules (i.e. hydrogen and gases with
applications in the development of fuel cells) or specific drugs and even for the design of
batteries and nanostructured electrodes. In this research we have used two different
experimental procedures to synthesize monodisperse hollow magnetites. In a first
procedure, a reflux method under inert atmosphere was used. The second procedure
consists of a hydrothermal process that includes several steps and is developed at
different experimental conditions (temperature and pressure). Both synthetic procedures
have been compared for determining the most efficient. The morphologies and
properties of the synthesized magnetites have been characterized by Scanning Electron
Microscopy (SEM). The results demonstrate that the experimental conditions, especially
temperature, decisively affect the morphology, size and magnetic properties.
MANAGEMENT RECOMMENDATIONS FOR THE REINTRODUCTION OF THE
PUERTO RICAN CRESTED TOAD (Peltophryne lemur) TO THE EL TALLONAL
NATURAL RESERVE, ARECIBO, PUERTO RICO
Ingrid M Flores-Vallejo1; Fred C Schaffner-Gibbs2
1
Doctoral Student, School of Science and Technology, Universidad del Turabo;
2
Profesor, School of Science and Technology, Universidad del Turabo
1
The Puerto Rican crested toad, Peltophryne lemur is the only native toad to Puerto Rico.
Peltophryne lemur is listed as Threatened by the United States Fish and Wildlife Service
(USFWS) and Critically Endangered by the International Union for Conservation of
Nature and Natural Resources (IUCN) and the Department of Environmental and Natural
Resources (DNER) of Puerto Rico. Due to the absence of sightings of the crested toad
in northern Puerto Rico; the Puerto Rican Crested Toad Recovery Group determined
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that the release of tadpoles for reintroduction the specie into wild in the north should be
done. In 2005, the conservation group “Iniciativa Herpetologica, Inc.” built three breeding
ponds at El Tallonal Private Natural Reserve in Arecibo, PR manage by Ciudadanos del
Karso (CDK) following the recommendations of the Puerto Rican Crested Toad
Recovery Group and Jorge Ortiz, hydrologist. The three ponds are different in the
percentage of canopy cover, diameter and the distance from the forest. In 2006, through
a memorandum of Understanding (MOU) between USFWS, DNER and CDK
approximately 4,000 tadpoles were released into the three constructed ponds at private
natural reserve. As a graduate student and volunteer of USFWS and member of the
Puerto Rican Crested Toad Recovery Group, I was assigned to monitoring the tadpoles
during their metamorphosis until as juveniles emigrated from the ponds. I evaluated the
physical and chemical parameters of the three ponds where Peltophryne lemur tadpoles
were released, such as temperature (°C), dissolved oxygen (mg/L), specific conductivity
(mS cm-1) and total dissolved solids (g L-1) to identify limiting factors that may influence
their metamorphosis. Also, Flores-Vallejo determined the initial orientation of juvenile
Peltophryne lemur during their emigration of each pond. This research also produces the
first photos of a juvenile Rhinella marina preying on a recently metamorphosed
Peltophryne lemur. This research also identified that canopy cover, water temperature
and dissolved oxygen are factors that limit the survival of tadpoles. Management
recommendations include the restoration of pond habitat without canopy cover,
reforesting around the pond and towards the karst formations. Other recommendations
include modifying the canopy cover of the other two ponds to minimize organic matter
falling into the water causing a decrease in dissolved oxygen concentration and to
increase sun exposure to raise the dissolved oxygen concentration by the growth of
photosynthetic algae. This study provides useful knowledge for the management of
future reintroductions to the recovery and conservation of this species.
SYNTHESIS AND CATALYTIC PROPERTIES OF IRON OXIDE NANOWIRES
Abraham García1, Carmen Bonilla1, Jose Ducongé1, Teresa Campo2, Eduardo
Elizalde2,Carmen Morant2, María C. Cotto1 and Francisco Márquez1
1
School of Science and Technology, University of Turabo, 00778PR, USA
2
Departamento de Física Aplicada C-XII, Universidad Autónoma de Madrid, 28049
Madrid, Spain
[email protected]
Organic dyes are some of the most common additives in industrial use, in manufacturing
processes and in consumer goods. This widespread use leads to high levels of dyes in
waste water and large bodies of water. These waste products contain compounds that
can be released into the waste water, poisoning the microbial and marine life, and
depleting the oxygen level in the water. These organic compounds can be made
harmless by decomposition by various means, including chemical, physical, and
biological processes. In the present research we have studied the degradation of three
common industrial organic dyes as test molecules, by using iron oxide nanowires as
catalyst. The catalytic activity of Fe2O3 nanowires (Fe2O3NWs) in Fenton processes
(Sono- and Photo-Fenton) is the focus of this study.Fe2O3NWs have been synthesized in
a quartz tube furnace, at temperatures ranging from 400 °C to 600 °C, in vacuum and
under oxidative/reductive conditions. The catalytic degradation processes of three
industrial dyes (Rhodamine B, Methylene Blue and Methyl Orange) were studied at
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pH=7. The dye concentrations in water were measured by UV-vis spectroscopy, TOC
(total organic carbon) analysis, and fluoresence spectroscopy. The results of this
research show that Fe2O3NWs can be considered as a highly active catalyst for the
degradation of organic pollutants. Besides, this chemical process is especially relevant
due to the simplicity of implementation, and its cost-effectiveness.
CONSUMO DE AGUA EMBOTELLADA Y SUS IMPLICACIONES GENERALES EN
EL AMBIENTE DE PUERTO RICO
WJ Guzmán – Pibernus, EK Pabón – Vázquez, J Arce – Nazario
Departamento de Biología, Universidad de Puerto Rico en Cayey
[email protected]
La percepción general de la población hacia su salud y calidad de agua en su hogar ha
generado un consumo exorbitante de agua embotellada en Puerto Rico teniendo un
impacto directo en el medio ambiente. El consumo de agua embotellada no solo afecta
el medio ambiente sino que también afecta el bolsillo de los consumidores. Esta
investigación estudia la cantidad de agua embotellada que consumen las personas en
los municipios de Cayey, Caguas y Comerío. Nuestros estudios se llevaron a cabo
durante los meses de marzo a agosto del 2012 mediante 288 entrevistas a individuos en
sus hogares. Los temas principales abarcaron demografía, salud y calidad de agua. El
48% de los entrevistados indicó que compra agua embotellada. Solo el 28% indicó que
el agua embotellada es su forma de consumo principal de agua. El 55% de los
entrevistados consume principalmente agua directamente de la pluma y el restante 17%
consume agua tratada en la casa mediante algún equipo de tratamiento. Modelos
logísticos utilizando el programa R muestran que la decisión de comprar agua
embotellada está correlacionado a la percepción de las personas sobre la calidad del
agua que sale de su pluma (p<.01) y su percepción de salud (p<0.01). Aquellas
personas que perciben que la calidad del agua de su casa es baja tienden a comprar
más agua embotellada. Las personas que indicaron que su salud es excelente o muy
buena tienden a comprar más agua embotellada. Entre las razones que tienen los
entrevistados para comprar agua embotellada se encuentran condiciones de salud,
sabor, entre otras. El consumo del agua embotellada de algunas personas entrevistadas
llegó hasta más de $600 dólares anuales pudiendo significar un gasto de 17% del
ingreso de la familia. Esta información es de suma importancia para nuestro ambiente
debido a que la generación de basura en Puerto Rico es tanta que ha contribuido al
cierre de varios vertederos alrededor de la isla. Entendemos que consumir el agua de
pluma representa una alternativa saludable, mucho más económica para las familias
puertorriqueñas y de menor impacto al ambiente.
LOS EFECTOS DE LA POBLACIÓN DE SPATHODEA CAMPANULATA SOBRE LOS
ÁRBOLES DEL SOTOBOSQUE DE LA RESERVA FORESTAL SANTA ANA
W Hernández-Nieves
[email protected] , [email protected]
La reserva forestal Santa Ana fue un área sumamente impactada por actividades
antropogénicas a través de los años. La agricultura y posteriormente la construcción de
búnkeres con fines militares produjo un impacto significativo. Esto creo condiciones
detrimentales para las posibles especies nativas y/o endémicas que pudieran estar
habitando el lugar a ese momento y permitió que especies oportunistas pudieran
establecerse. Una de estas especies lo fue la Spathodea campanulata o tulipán
africano, la cual es una especie heliófila que gusta de suelos nutricionalmente
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empobrecidos o altamente degradados. Para llevar a cabo la investigación se
plantearon las siguientes preguntas: ¿Qué características o adaptaciones posee la S
campanulata que le permite entrar en estos tipos de suelos? ¿Qué condiciones
microclimáticas se crean el bosque dominado por la S campanulata? ¿Cómo se afecto
la biodiversidad de árboles en el bosque a raíz de las actividades antropogénicas? Para
llevar a cabo la investigación se escogieron los valles norte y sur para medir el impacto
de la actividad humana. El valle norte fue el más impactado no así el valle ubicado en el
sur del bosque. Se ubicaron dos parcelas de 1000 m2, una en cada área de estudio.
Luego de establecer ambas parcelas se procedió a contabilizar todos los árboles que
midieran más de 30 cm de altura y el diámetro de estos. Se clasificaron los mismos por
su altura como briznal (≤2.5 cm), juvenil (>2.5 ≤10 cm) y adulto (>10 cm). Estos se
contaron e identificaron para establecer la dominancia por la estructura del bosque. Se
encontró que la Faramea occidentalis domina el área del sotobosque, que la Casearea
guianensis domina el intermedio y que el Hura crepitans domina el dosel del bosque.
Cuando comenzamos a realizar la investigación se presuponía que la S campanulata
dominaría el dosel, esto fue así debido a que durante el recorrido inicial se observó una
dominancia de esta especie. Los resultados preliminares muestran un cambio en la
estructura y composición del bosque donde se observa una dominancia de especies
nativas en el área. Se utilizó el índice de Shannon-Weiner para medir biodiversidad y se
encontró que el bosque presenta una buena de diversidad de especies arbóreas en el
lado norte. Se presume que hace unos 70 años el área estudiada era un monocultivo de
S campanulata. El bosque ha sufrido un cambio en su estructura en los últimos 100
años debido a las presiones de las actividades humanas que se han desarrollado en su
entorno. No se puede dar una conclusión sobre el resultado de la investigación ya que
esta todavía está en progreso pero preliminarmente se puede establecer que la
población de Spathodea campanulata ha tenido un impacto positivo sobre las especies
que se han ido desarrollando en el sotobosque del Bosque Santa Ana. La recuperación
del área a partir del impacto de las actividades antropogénicas es un indicador de este
efecto, debido a que la especie ha permitido el desarrollo de especies que no
representan una competencia directa por la luz solar, creando condiciones de un dosel
abierto, lo que permite la entrada de luz, cambios en temperatura y la humedad relativa,
lo que crea condiciones idóneas para el desarrollo de especies nativas y endémicas.
DISTRIBUTION AND DIVERSITY OF FUNGI ACROSS TROPICAL COASTAL
ECOSYSTEM
DL Laureano-Córdova2; Y Bernier-Casillas1,2; and JR Perez-Jiménez1,2
1
Puerto Rico, USA
[email protected]
Mangroves, as a biome, sustain highly productive ecosystems while been subjected to
coastal dynamics. On the coast, estuarine sediments constitute an unusal habitat for
fungi. Puerto Rico is bordered by mangroves and has the second largest estuary (Jobos
Bay) managed as a national reserve. As fungi are considered primary decomposers of
complex organic matter, we aimed to describe the heterogeneity and biogeography of
fungi in those tropical coastal ecosystems. The composition of fungal communities was
characterized by amplification of partial ITS from soil and sediment samples for Terminal
Restriction Fragment Length Polymorphism (TRFLP). DNA extraction was performed on
91 samples, but the ITS was amplified in only 24 positive samples. A total of 1329 m
phylotypes (TRFs) were detected, representing 345 different TRFs (richness). Fungal
community in mangroves oscillated between 23 n (Vieques) and 152 (Maunabo) TRFs
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whereas in Jobos Bay oscillated between 18 (CNT18) and 79 (OTR37). Currently, no
TRF was found in common among all samples. Only one sample detected 29% of the
picks, suggesting potential endemism. Similarity analyses, based on the Sorensen
index, illustrate the association with geographic proximity. The similarity index fluctuated
between 19% and 72%, and was highest among neighboring sites. The application of
TRFLP provides information on fungi diversity, and shows that the fungal Community is
distinctive for mangrove and sediments ecosystems. Evaluations of clonal libraries are in
progress to identify specific taxa.
SYNTHESIS AND CHARACTERIZATION OF HOLLOW MAGNETITE
MICROPARTICLES AND THEIR APPLICATIONS AS DRUG CARRIERS
M Cotto1, T Campo2, JM Sanz2, E Elizalde2, C Morant2, J Ducongé1, F Márquez1
1
Turabo, 00778PR, USA
2
Departamento de Física Aplicada, M-XII, Universidad Autónoma de Madrid,
[email protected]
During the last few years, magnetic oxides particles have attracted a great deal of
attention due to their interesting advantages in different fields such as catalysis,
information storage, optoelectronics and biomedical applications. Among these magnetic
materials, magnetite nanoparticles with an interior void, represent an interesting family of
nanostructures with relevance in biological applications. These materials are
characterized by having a large surface area, a very low density and also a strong
magnetic response that make them candidates for a number of potential applications.
Thus, the internal hollow spaces may potentially be used as hosts for the encapsulation
of guest molecules or specific drugs. In the present work we have synthesized
monodisperse hollow magnetite microspheres by using an one-step solvothermal
procedure. To increase the solubility in polar solvents in avoiding aggregation, these
microspheres were surface modified by growing SiO2 nanolayers via sol-gel process.
Primary (hollow magnetite microspheres) and modified microspheres (SiO 2@hollow
magnetite microspheres) have been used to encapsulate and to study the release of
methotrexate (MX) and vincristine (VN), chemotherapy drugs used in treating certain
types of cancer. The release of these compounds has been shown to depend on the
temperature and pH value of the environment, indicating that these magnetite
microparticles could have interesting applications as drugs carriers in living organisms.
PHOTOCATALYTIC HYDROGEN PRODUCTION BY WATER SPLITTING USING
ZNCDCUFES NANOPARTICLES UNDER UV-VIS LIGHT IRRADIATION
A Masa1, A García1, M Cotto1, J Ducongé1, C Bonilla1, T Campo2, E Elizalde2, C Morant2
and F Márquez1
1
2
Cantoblanco, 28049 Madrid, Spain.
[email protected]
Photocatalytic hydrogen generation by water splitting (H2O(l)→H2(g)+1/2O2(g)) has been
studied on photocatalysts based on Zn, Cd, Cu and Fe, obtained by coprecipitation of
ZnS, CuO and CdS. Nanosized Fe has been incorporated into the structure as cocatalyst to enhance the photocatalytic activity of the ZnCdCuS solid solution. The effects
of the different experimental conditions (synthesis temperature, elemental atomic ratios,
amount of nanosized iron incorporated in the catalysts and treatment temperatures)
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have been tested in order to determine the best experimental synthesis conditions. The
catalysts have been characterized by X-ray diffraction (XRD), field emission scanning
electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS) and Raman
spectroscopy. The experiments of photocatalytic water splitting were performed in
aqueous solution of the photocatalyst previously dispersed in a soft ultrasonic bath. The
photocatalysts were irradiated under different lights ranging from 220 to 700 nm. The
rate of hydrogen production has been correlated with the increase of Fe concentration,
showing the best results under UV irradiation. With the aim to increase the catalytic
activity, nanometric particles of ZnCdFeCuS were dispersed on the surface of TiO 2
nanowires. The resulting adducts showed very high catalytic activity with rate of
hydrogen production ranging from 1150 to 1470 μm.h-1.g-1 under visible irradiation.
These results open a new route for the synthesis of high-active catalysts.
Silica Nanospheres and Their Application as Supporting Material for the Growth of
Si Nanowires
A Gómez-Martínez1, T Campo1, S Pinilla1, F Márquez2, E. Elizalde1 and C Morant1
1
2
Turabo, 00778PR, USA;
[email protected]
Li-ion batteries are widely used due to their many advantages over other devices, such
as the lightness of its components, its high energy density and shock resistance,
absence of memory effects or its ability to operate a large number of cycles. The storage
of energy in lithium-ion batteries is a challenge in the development of new materials as
electrodes, demanding an intense investigation in relation to the synthesis and control of
their morphological, electrical and structural properties. Nevertheless, the main
disadvantage of the lithium-ion batteries is its rapid degradation. A possible strategy to
solve this problem is the use of nanostructured materials in the electrodes. In this
research, we present an appropriate method to synthesize Si nanowires (Si NWs) on
silica nanospheres for future applications in the development of anodes of Li-ion
batteries. Silicon nanowires have been synthesized by a Chemical Vapor Deposition
(CVD) process at 900 °C in flowing a mixture of H2 and Ar, over monocrystalline Si
<100> wafers, which were used as substrates. In order to enhance the active surface
area and increase the Si NWs growth, silica nanospheres were also deposited by spin
coating on the Si <100> substrates before the catalyst deposition and CVD synthesis.
The synthesized Si NWs have been fully characterized by AFM, FESEM and HRTEM
microscopies, X-ray diffraction and EDX analysis. As a result, high density and good
quality Si NWs have been synthesized using silica nanospheres as supporting material.
The mechanism of synthesis has been considered to follow a vapor-liquid-solid (VLS)
model. The small dimension of catalytic particles is a critical factor, and the appropriate
size (60-80 nm) has been only achieved on silica nanospheres.
A-16
A COMPARATIVE STUDY IN DECOMPOSITION, NUTRIENTS AND ARTHROPODS
AMONG NATIVE AND EXOTIC TREES IN AN URBAN FOREST
Olga M Jiménez Osorio and María Fernanda Barberena-Arias PhD,
[email protected]
Plant species influence the decomposition processes through the quality of residues
they produce. These differences in quality in turn influence the organic matter and the
associated fauna that develops beneath them. A dominant component of litter fauna are
arthropods, which play a critical role in litter decomposition through trophic interactions
and thus influence nutrient cycling. On the other hand, human disturbances have
created urban forests where exotic species are a dominant component altering the plant
species composition of forests. Little is known on how the introduction of exotic plant
species influences ecosystem processes such as decomposition, and the associated
litter fauna community in tropical urban forests. As a consequence it is important to
determine how litter decomposition and the arthropod fauna compare among exotic plant
species and native species in a tropical forest totally enclosed in an urban matrix. Puerto
Rico has been largely disturbed by human activities resulting in the co-occurrence of
exotic and native plant species in puertorrican forests. This study will compare litter
decomposition and litter arthropods among two exotic pioneer plant species Spathodea
campanulata Beauv. and Albizia procera (Roxb) Benth, and one native pioneer plant
species, Schefflera morototoni (aubl) Maguire. The following questions will be
addressed: (1) How do litter arthropods abundance, richness and composition change
between exotic and native species? (2) How do nutrients (C, N, P) change between
exotic and native species? and, (3) How do litter decomposition rates differ between
native and exotic species? To answer these questions, nine plots were selected: three
plots dominated by S campanulata, three plots dominated by A procera and three plots
dominated by S morototoni. Within each plot, litterbags will be placed at the same time,
and retrieved after 25d, 100d, 175d, 250d, 375d, and 450d. This experimental design will
give 54 litter bags date-1, representing each of the seven treatments from each of the
study plots. This will produce a total of 324 litter bags. The bags will be filled with litter
from the three plants species in several combinations and alone to represent seven
treatments. Nutrient and arthropod data will be collected. Variations in the abundance,
richness and composition of arthropods associated to individual plots will be determined
using the analysis of variance (ANOVA) and differences in decomposition and nutrient
content will be also assessed using ANOVA.
MICROBIAL COMMUNITY ASSOCIATED WITH THE YEAST AGRICULTURE-ANT
CYPHOMYRMEX MINUTUS
Mariely Medina-Rivera1 and Matías J Cafaro1
1
University of Puerto Rico at Mayagüez Campus,, Biology Department, Symbiosis
Laboratory
1
[email protected]
The attine ants cultivate a fungus (Basidiomycota: Lepiotaceae) as food and protect it
from specific pathogens (Ascomycota: Hypocreales) using the antibiotic production
capacity of Actinobacteria (Pseudonocardia). In addition, the ant show hygienic
behaviors that included farming and grooming of the cultivar creating, rearranging, and
transporting piles of organic refused material in and out of the nest. In Puerto Rico,
Cyphomyrmex minutus is the only attine species that practices yeast agriculture. Neither
the parasite nor Pseudonocardia have been described in this system. Although the
interaction in the attine ant symbiosis has been extensively studied, the yeast-cultivating
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ants and their microbial associates in the Caribbean have not been described. We
investigated the microbial community associated with C minutus including the specific
cultivar, the possible pathogens and the Actinobacteria. We sampled a total of 25 nests
of C minutus during the Dry and Rainy seasons at Cambalache Tropical Forest in Puerto
Rico. A combination of culture-dependent and independent techniques was used to
describe the fungi and Actinobacteria isolated from different components of the nest. We
identify the yeast cultivar with 28S rDNA. We isolated and identify all the microfungi
associated with the cultivar using morphology and ITS sequencing. Also, we created a
clone library of the ITS region from the organic refuse material. Actinobacteria genera
from the ant exoskeleton and the cultivar were analyzed using 16S rDNA. The microbial
community associated with C minutus differs significantly from other attine ants. The
specific pathogen, Escovopsis (Ascomycota: Hypocreales), was not found in the cultivar
or the refuse material. Pseudonocardia was not the prevalent genus in the association,
but instead Streptomyces strains were commonly recovered. Our studies suggest the
ant maintains the cultivar as yeast as an adaptation to escape pathogen infection.
Further testing is needed to investigate this hypothesis.
ASSESSMENT OF VEGETATION BIODIVERSITY IN THE KARST FOREST
SURROUNDING THE ARECIBO OBSERVATORY, LOCATED IN THE NORTHERN
KARST OF PUERTO RICO
Ivia Moreno1 ; Maria F Barberena-Arias2
1
Universidad Metropolitana; 2School of Sciences and Technology, Universidad del
Turabo
[email protected]
The term karst describes a type of rock formed by calcium carbonate that dissolves in
the presence of acidic water. In Puerto Rico the karst region covers approximately
27.5% of the surface of the island (about 244.285 hectares) where forests contain more
tree species per unit area when compared to other areas in Puerto Rico. Currently 27
species of plants living in the karst region of Puerto Rico are officially endangered while
other 120 species of vascular plants are considered to have critical populations. Even
though this region contains a high diversity of organisms, few studies have assessed the
diversity of forests surrounding the Arecibo Observatory. As a consequence, the
objective of this project was to begin a description of the flora associations inhabiting this
area. For purposes of this project, the study was conducted in the area of the northern
limestone, known as "marginal karst" specifically in the forest surrounding the Arecibo
Observatory. The specific objective was to initiate an inventory of the forest flora and
endemic or endangered species. Two field trips were made and active exploratory
search was used. In each area the search was conducted for one hour. We found the
flora of this forest to contain species characteristic of humid climate, and to be rich in
ferns and shrubs. Some species endemic and endangered were identified. The endemic
species include (Cassia mirabilis) Chamaecrista glandulosa, (Roble Cimarron)Tabebuia
haemantha and (Cupey) Clusia krugiana. This is an area less disturbed, this factor could
be of great importance for the conservation of these species. This information will be
used as part of a study that will be developed in the biodiversity of karst forest
ecosystem in Puerto Rico.
IDENTIFYING CONCERNS TO PREVENT ENVIRONMENTAL IMPACT DUE TO THE
PURCHASE OF BOTTLED WATER AT THE COLLEGE OF NATURAL SCIENCES OF
UPR AT RIO PIEDRAS
A-18
Amira Odeh (Environmental Science), Zoelie Rivera Ocasio (Biology), Ninoshka Morales
(Program of Nutrition), Yatnee Encarnación (Interdisciplinary Science), Jennifer Carde
(Modern Languages), all from University of Puerto Rico, Rio Piedras Campus
[email protected]
The use of bottled water is directly related to the making of a larger carbon footprint,
great quantities of waste, waste of water resources and human health hazards. In the
island of Puerto Rico there is an excellent tap water quality, tested constantly and
approved by the EPA and Health Department, but even though this is the case, people
continuously buy bottled water. In the College of Natural Sciences (CNS) at the
University of Puerto Rico, Rio Piedras Campus, there is a constant waste problem
related to the selling of water bottles due to the fact that about 30% of those sold are
discarded in public places on a weekly basis and only a minimum quantity is deposited
at recycling bins. Several approaches were made to study the reasons why people
choose bottled water over tap. This study consisted of two surveys and a campaign,
where the first survey investigated general knowledge about water and environmental
conservancy and a second one helped analyze the effectivity of the campaign on
students of the CNS. Some actions taken for the campaign were the presentation of a
documental, showing an exhibition, water taste examinations, handing out information,
offering interviews to radio and online news websites, among others. The two surveys,
where ~200 people were interviewed for each, were analyzed and compared to reveal
that 86% of students believe that water scarcity will affect them severely and 88%
believe that water should be conserved, while the other 12% are either unsure of believe
it is not necessary. Also, it revealed that even though most people learned about the
negative effects of bottled water on the environment and health, more than half still buy
the product and about 45% never realized that there are new, free and clean water
fountains available at the CNS. In due course we will continue to expand the campaign
and study possibilities to promote sustainable projects at the CNS and the UPRRP
campus.
ENTOMOFAUNA ASOCIADA A Auricularia spp EN BOSQUES DE LA OLIMPIA Y
RÍO ABAJO, EN PUERTO RICO.
C Osorio-Quintero y SL Maldonado Ramírez
Departamento de Biología, Universidad de Puerto Rico, Recinto Universitario de
Mayagüez
[email protected]
Los insectos asociados a los macrohongos son un componente importante de la
diversidad en los bosques. La principal relación que se establece entre estos dos
organismos es la micofagía. Puerto Rico cuenta con un clima propicio para el cultivo de
macrohongos comestibles, por tanto es necesario conocer la entomofauna asociada a
ellos y su interacción en estado natural. En este estudio se determinó la entomofauna
asociada al hongo comestible Auricularia en dos bosques de Puerto Rico: La Olimpia y
Río Abajo. Se recolectaron 364 insectos asociados a Auricularia, de los cuales 159 se
distribuyen en 7 órdenes, colectados durante el día y 205 distribuidos en 7 ordenes
colectados durante la noche. Los muestreos se realizaron en el campo, con ayuda de
un aspirador entomológico en 30 unidades de esfuerzo de muestreo. El grupo de los
colémbolos presentó la mayor abundancia 0.443 y 0.439, durante las colectas diurnas
en ambos bosques. Este grupo también fue el más abundante 0.495 para la colecta
nocturna en el bosque La Olimpia, mientras que el orden Hemíptera presentó mayor
abundancia 0.375 en el bosque Río Abajo. El bosque La Olimpia presentó una mayor
riqueza de especies diurnas, con respecto al bosque Río Abajo y para las especies
nocturnas la riqueza fue similar para ambos bosques. Sin embargo hay evidencia de
A-19
que la diversidad proveniente de las muestras de entomofauna asociada a Auricularia
en los bosques de La Olimpia y Río Abajo es diferente. También se encontró diferencia
en la diversidad de la entomofauna diurna y nocturna para Auricularia, observando una
mayor abundancia de insectos durante las colectas nocturnas. Los resultados obtenidos
en este estudio podrían contribuir al desarrollo de estrategias de control de plagas en
cultivos de hongos comestibles y al uso de cepas nativas en Puerto Rico.
POPULATION ESTIMATE AND DISTRIBUTION PATTERNS OF NEW WORLD AND
OLD WORLD MONKEYS IN PUERTO RICO
Glorienell Pérez-Vélez ¹*, Adaris Mas-Rivera ² and Armando Rodríguez-Durán ¹
¹Universidad Interamericana de Puerto Rico - Bayamón, ²Universidad del Turabo*
[email protected]
Populations of free-ranging common squirrel monkey (Saimiri sciureus) and rhesus
monkey (Macaca mulatta) have been identified in a secondary growth forest along the
karst area of Toa Baja, Puerto Rico. A year study using direct observations and baiting
stations was performed to collect information on population sizes and dispersion of both
species. We propose that two populations of squirrel monkeys and two populations of
rhesus monkeys inhabit this 9.11 km2 forested karstic area in Toa Baja. The squirrel
monkeys estimated population is of 70-90 individuals and its population density is 21.4
individuals km-2. The estimated population for the rhesus monkeys is 85-105 individuals
and the population’s density is 25.5 individuals km-2. Out of the total 9.11 km-2 that
comprise the study area, both species populations’ are concentrated in 3.73 km2. The
distribution and availability of food resources could be contributing to the distribution of
both species. Food resources consumed by both primates are endemic and exotic
species that include: Roystonea borinquena, Terminalia catappa, Artocarpus altitis,
Persea americana, Syzygium jambos, Hymenaea coubaril, Genipa Americana,
Passiflora edulis var. flavicarpa, Passiflora coerulea, Spondias mombin, Delonix regia,
Spathodea campanulata and Thespesia grandiflora.
EFFECTS OF LIGHT ON FRESHWATER ECOSYSTEMS
Alma C Ramírez Vélez
Estudiante de Ciencias Ambientales, Universidad Metropolitana Recinto Cupey
[email protected]
Trapa natans, commonly known as water chestnut, is an invasive aquatic plant native
from Eurasia introduced to the Hudson River in the late nineteenth century. Since then, it
has changed the ecosystem by forming floating mats of leaves that block entering light
and cause oxygen depletion. Organisms that depend on oxygen, light, or both have
been threatened by T. natans. Therefore, the important question is: how much light is
needed to support a submerged ecosystem beneath a water chestnut canopy? I
hypothesized that a submerged ecosystem will have a higher concentration on dissolved
oxygen and higher organism survival with a higher percentage of light entering. To test
this, I controlled the percentage of light entering in each of 11 different mesocosms and
measured temperature and dissolved oxygen, as well as the growth and survival of
several organisms. So far, the results suggest that at least temperature and dissolved
oxygen depend on the percentage of light entering the ecosystem.
CAVE WEATHER AND CLIMATE IN PUERTO RICO
RT Richards
Doctoral Student in Environmental Science, Universidad del Turabo
[email protected]
A-20
Diurnal and annual cycles of air temperature and humidity are much smaller in a cave
than on the surface. For this reason any single measurement in a cave is much closer to
the long-term average than on the surface. The author has collected air temperature and
relative humidity data in 32 caves in Puerto Rico during 74 trips. In April 1983 Cueva
Cucaracha in Aguadilla had a temperature of 35 °C and a bat population of 700 000.
Nobody has ever counted the bats a second time so we do not know if the population
has changed. Nobody has ever counted how many cockroaches live in Cueva
Cucaracha. The cave is heated by the bats to about 10 °C above ambient conditions. In
June 2012 the maximum temperature in the cave was 35.3 °C and the relative humidity
was 97.6 percent. The conditions were bad for the cavers. The trip was cut short
because many people had labored breathing probably due to elevated levels of carbon
dioxide. This is good news for conservation biology because if the bat population had
crashed to 7000 then the temperature would also have crashed. The temperature data is
consistent with a stable bat population over a 29 year period. In many geologic
environments rain is colder than ambient conditions. The coldest cave in Puerto Rico is
Cueva Tunel #1 in Utuado. In December 2010 this cave was 19.5 °C with 100 percent
relative humidity. The Río Tanamá flows through this cave. The data was collected while
floating in the river. The least humid cave in Puerto Rico is Cueva Ventana in Arecibo
with an average air temperature of 24.4 °C and 81.4 percent relative humidity. This cave
is the least humid because it is the best ventilated. The cave has two entrances and an
east-west orientation. At the constricted western entrance the wind can be felt as it
blows through the cave. The average air temperature in the caves is 24.4 °C with a
standard deviation of 2.3 °C. The distribution is normal. The average cave relative
humidity in Puerto Rico is 93.3 percent with a 4.5 percent standard deviation. The
distribution of relative humidity is not normal as normality would require a tail with values
above 100 percent which is not possible. White Nose Syndrome is caused by a fungus
(Geomyces destructans) and has killed 6 million hibernating bats in the United States. In
laboratory studies the fungus cannot grow above 20 °C. White Nose Syndrome is not
expected to reach Puerto Rico because the caves are too warm and the bats do not
hibernate. The Puerto Rico boa (Epicrates inornatus) has been found in the four
warmest caves in Puerto Rico. Some bat species prefer to live in hot and humid caves
because it reduces their consumption of energy and water. The hottest caves have a
single constricted entrance at lower elevation than the bat roost. The constricted
entrance gives an opportunity to predators such as the boa.
BIOINFORMATIC ANALYSES OF THE ARSENATE RESPIRATORY REDUCTASES
AMONG NON-FIRMICUTES BACTERIA
M Rivera-Sánchez1, 3; JR Pérez-Jiménez1, 2, 3
1
3
Puerto Rico, USA
[email protected]
Arsenic is a toxic element found in nature, it affects human health by causing different
types of cancer, neurological and skin disorders. Arsenic is an odorless, colorless and
tasteless toxin capable of being dissolved in water. For these reasons arsenic species
are almost impossible to detect when present in food, water and gasses. Recent
discoveries have shown that some bacteria can transform arsenic species into more
toxic compounds through reductive mechanisms. Dissimilatory arsenate-reducing
prokaryotes (DARPs) respire arsenate, mobilizing arsenic into water. The non-Firmicutes
DARPs represent several phylums in Chrysiogenes arsenatis, Geobacter lovleyi, G.
uraniireducens, Halanaerobiaceae sp. strain SLAS-1, Sulfurospirillum arsenophilum, S
A-21
barnesii, S carboxydovorans, Shewanella spp ANA-3, Shewanella putrefaciens, and
Wolinella succinogenes. Our goal is to strengthen screening tools with a new method in
order to examine the prevalence and diversity of DARPs in nature through the
employment of bioinformatics analyses. The prevalence of DARPs in nature is being
assessed by the presence of the arrA gene among microbial genomes. The arrA gene
from Sulfurospirillum barnesii was subjected to blast analyses among non-Firmicutes
genomes (1470). Higest homology was found for three genomes: Wolinella
succinogenes (71%), Shewanella putrefaciens (74%), and Shewanella sp. ANA-3 (74%).
Shewanella species demonstrated large centers of divergence in the middle (~80%
coverage). Less homology was detected at nucleotide level than the amino acid
sequence. The arrA genes are highly divergent to find sites that flank central islands of
difference to support a new detection method. Conserved sequences are useful
biomarkers to ascertain prokaryotes capable of arsenate respiration; this will allow us to
monitor the risk of arsenate mobilization in nature.
MANGROVE ARTHROPOD COMMUNITIES INCLUDE 50% OF UNIQUE SPECIES IN
JOBOS BAY NATIONAL ESTUARINE RESEARCH RESERVE
Anivonne Robert Santiago1; MF Barberena-Arias2
1
BS Biologia, School of Sciences and Technology, Universidad del Turabo
2
Associated Professor School of Science and Technology, Universidad del Turabo
[email protected]
Mangroves develop in coastal areas providing habitat for organisms, such as
arthropods, that play a significant role in several ecosystem processes such as nutrient
cycling through herbivory, seed dispersal, detritivory, predation and pollination. In Puerto
Rico, mangroves are threatened by urban development, natural disturbances and sea
level rise. Despite their importance, arthropod biodiversity in mangroves is scarcely
known; as a result we aim to establish arthropod biodiversity in mangroves and
surrounding habitats, and determine if they are a unique community. For this we studied
terrestrial arthropods in mangroves and surrounding forests in two seasons, wet
(September-October 2011) and dry (March 2012). The surrounding habitats included
areas in several stages, such as inactive agricultural fields, early abandonment (~5 y),
planted and naturally recovered habitats (~15 y), and >40 y forests. We used two
sampling methods: branch clipping and butterfly nets. Collected arthropods were placed
in a labeled vial with alcohol. Arthropods were sorted, counted and identified to order.
Arthropod abundance and richness was highest in the >40 y old forest when compared
to the other habitats, but species composition was different among habitats. Arthropod
species composition in the mangrove forest was ~50% similar to the dry forest, as well
as trophic composition. Arthropod abundance and richness in mangroves was not as
high as expected possibly because mangrove extreme conditions (such as high salinity)
limit arthropod abundance. These data suggest that mangroves are extreme habitats
that exhibit an arthropod community composed of common and unique species.
NANOMATERIALS FOR CATHODE OF FUEL CELLS
Edaris Rodriguez and S Nieto
School of Science and Technology, Universidad del Turabo
P.O. Box 3030, Gurabo, P.R. 00778
[email protected]
On the most critical challenges facing the world is the development of clean, reliable,
and efficient energy conversion processes. The demand for energy will inevitably
increase and this increasing demand must not compromise the environment. Fuel cells
are energy conversion systems that efficiently generate electricity for stationary or
A-22
transportation application from fuels like hydrogen or hydrocarbons. There are various
types of fuel cells. Among them, solid oxide fuel cells (SOFCs) are very promising
because they offer flexibility in terms of the type of fuel. The challenges hindering SOFC
commercialization arise from their high operating temperature. Developing an SOFC
able to operate in the so-called intermediate temperature range (IT, 450-650 °C) are
needed. Reducing the SOFC operating temperature leads to two main problems: a
decrease in electrolyte conductivity and an increase in electrode polarization losses,
because both the ion transport in ceramic electrolyte and the electrochemical reaction at
the triple phase boundary (TPB) are thermally activated processes. Nanomaterials play
a key role in the SOFCs, large surface area (nanopores) are needed for oxygen
transport within the air electrode, as well as hydrogen and water transport within the fuel
electrode. In this research (Ba0.5Sr0.5)1-xNdxCo0.8Fe0.2O3- (BSNCFO) (0.00  x  0.20)
compound were synthesized by the solid state reaction method, and characterized by
powder X-ray diffraction (XRD), the samples were submitted at a cavitation process and
after that structurally studied by scanning electron microscope (SEM). The results
indicated that we have developed a top-down method for fabrication of nanoparticles for
IT-SOFC.
INFERENCE OF HABITAT CONNECTIVITY VIA HABITAT USE BY SONG BIRDS
BETWEEN HABITATS IN JBNERR, PUERTO RICO
Ivelisse Rodríguez-Colón1,2 and Fred C Schaffner1
1
Graduate Program in Environmental Science, Universidad del Turabo, Gurabo, Puerto
Rico,2Jobos Bay National Estuarine Research Reserve, Aguirre Puerto Rico.
[email protected]
This research addressed whether several species of migrant warblers moved between
mangrove night-roosts and daytime foraging habitat in dry secondary forest. Early
morning fixed-radius point counts performed between (Sep 2010-August 2011), revealed
eleven (11) migratory and resident warbler species in black mangrove, red mangrove
and secondary dry forest. Observations from blinds established in gaps between
mangrove and dry forest within two hours of sunrise and sunset revealed nearly
unidirectional movement by several species tree-hopping through the corridor from
mangroves after sunrise and to mangroves before sunset. Mist netting during February –
April 2011, during the first and last two hours of the day revealed diurnal mostly
unidirectional movements in several migrant species. Migrants represented 62% of all
captures. Arthropod samples were collected in mangrove forest and secondary dry
forest using active searching on the ground with the quadrat technique and in the
canopy foliage by the branch clipping technique. Results from this analysis showed that
the number of prey items and biomass available in canopy samples is higher in
secondary dry forest than in mangrove forest, but no significant difference was found.
Results from quadrat technique revealed that secondary dry forest provides a good
source of arthropod biomass as well. These results underscore the importance of
secondary dry forest to this avian guild, despite the preference by most species for
mangroves as nighttime roosts.
DINÁMICA INTERNA DE FÓSFORO EN LAGUNA CARTAGENA
YM Sánchez-Colón1; FC Schaffner2
1
Estudiante Doctoral, Escuela de Ciencias y Tecnología, Universidad del Turabo;
2
Profesor, Escuela de Ciencias y Tecnología, Universidad del Turabo
[email protected]
La Laguna Cartagena, ubicada en el suroeste de Puerto Rico fue originalmente un
ecosistema oligotrófico, de agua abierta y abundante vida silvestre. Sin embargo, en la
A-23
segunda mitad Siglo XX, este ecosistema fue impactado por las altas cantidades de
fósforo provenientes de las áreas agrícolas adyacentes vía el sistema de riego y
desagüe, causando una severa eutrofización o enriquecimiento de nutrientes en la
laguna. El reciclaje interno de fósforo entre el sustrato y la columna de agua ha causado
que las concentraciones de este nutriente permanezcan dramáticamente altas, aun
cuando las entradas externas de fósforo a la laguna han disminuido y a pesar de que
los niveles de éste han decrecido de 1 500 µg L-1 a 50-300 µg L-1. Estas condiciones
han modificado la estructura y función de la laguna, incluyendo la reducción geográfica
del área de agua abierta del ecosistema y la degradación del hábitat de las aves
acuáticas debido al aumento en materia orgánica acumulada. El objetivo de este trabajo
era caracterizar la dinámica de fósforo y la eutrofización interna, los cuales controlan la
producción primaria y la liberación de fósforo bajo niveles de agua y régimen de
precipitación variables en la laguna. Laguna Cartagena tiene un sumidero (almacén) de
fósforo en el sustrato y en la biota del ecosistema; pero experimenta dramáticos eventos
de fuente (liberación) de fósforo, como es descrito en modelos estadísticos basados en
el régimen hidrológico (fluctuaciones en los niveles de agua, una semana antes de la
recolección de las muestras) y la precipitación (una y dos semanas antes de la
recolección de las muestras). En los periodos de sequía las plantas intolerantes a las
inundaciones (varias plantas terrestres y las eneas, Typha domingensis) y los
macrófitos flotantes (Pistia stratiotes y Eichhornia crassipies) almacenan fósforo, pero al
descomponerse liberan fósforo total de vuelta a la columna de agua, aumentando la
materia orgánica en la laguna y promoviendo un almacenamiento de nutrientes a largo
plazo. Esta dinámica del fósforo, de igual forma, depende de la actividad de las
comunidades microbianas y de las condiciones anaeróbicas que existen en la laguna.
Estos resultados indican que es necesario modificar la hidrología (ciclos de sequía y
abruptos flujos de agua) en Laguna Cartagena, para poder reducir la eutrofización
interna y así conservar la biodiversidad que éste humedal de agua dulce tropical posee.
A-24
Appendix Two
Abstracts from the Ambientis Symposium held 22
November 2013
____________________________________________________
EFFECTS OF OUTWELLING ON THE METABOLISM OF THE YORK RIVER
ESTUARY, VA
Alma C Ramírez Vélez, Universidad Metropolitana, San Juan, Puerto Rico.
Research Mentor: Dr. Mark J. Brush, Virginia Institute of Marine Sciences, Gloucester
Point, Virginia.
[email protected]
Since the early 1970s, the concept of outwelling has been a consistent and sometimes
debated focus of research in estuarine ecology. In at least some cases, marshes appear
to export organic matter, dissolved inorganic carbon (DIC), and dissolved nutrients to
adjacent open water systems. It was hypothesized that outwelling of DIC and water low
in dissolved oxygen from salt marshes and tidal creeks can help explain the discrepancy
in estimates of net ecosystem metabolism (NEM) in the York River Estuary, VA. The
YRE has been classified as net heterotrophic based on in situ measurements of excess
DIC and supersaturated CO2, and net autotrophic based on metabolic incubations of
water and sediments. A multi-creek survey was conducted to measure the potential for
import or export of nutrients, particulates, and DIC in several marsh-dominated tidal
creeks in the YRE. Additionally, NEM was determined in a representative salt marsh
system, Taskinas Creek, and the YRE, and 24-hour exchanges of DIC were measured
between Taskinas Creek and the YRE. For metabolic incubations, creek and marsh
sediments, and creek and York River water samples were collected to measure changes
in dissolved oxygen concentrations in the light and in darkness. Results indicated the
potential for export of DIC and a variety of other parameters in creeks throughout the
YRE. The York River estuary was net autotrophic while Taskinas Creek was net
heterotrophic. DIC fluxes between Taskinas Creek and the YRE were tidal stage
dependent, but the overall flux was a net export from the creek to the river. Overall,
results indicate that saltwater marshes and tidal creeks around the YRE show potential
for outwelling of DIC and nutrients which could bias estimates of open water NEM and
explain the discrepancy in past estimates of NEM.
ASSESSMENT OF GENETIC HOMOLOGY FOR EFFECTIVE DETECTION OF
MYCOPLASMA
LV Arroyo-Cruz1, JR Pérez-Jiménez1
1
Doctoral Program in Environmental Sciences, School of Science and Technology,
Universidad del Turabo, Gurabo, Puerto Rico
[email protected]
The Mycoplasma genus (Mollicutes class) has a high impact on public health, veterinary
science, biotechnology, and the environment due to the versatile life style that induces
serious damage and disease. New habitats are being reported recently in biofilms and
corals. Current molecular markers developed for clinical applications are anticipated to
be limited on detecting diversity of the genus Mycoplasma in the natural environment.
The emerging knowledge on the genetics of mycoplasmas can be exploited to propose
new and/or more extensive application tools. This way, these biomarkers can be
evaluated and extended to new environmental and artificial scenarios. The objective of
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this research was to assess the genetic homology for 16S rDNA on Mycoplasma
complete sequenced genomes to revisit effective detection of mycoplasmas. Sequences
of available oligonucleotide primer and Mollicutes 16S rRNA gene database were
obtained from NCBI and journals. Genetic homology for 16S rRNA gene of Mollicutes
was determined from complete genome using Genomic BLAST. Efficiency of four
previous published primers was assessed in terms of primability and stability using the
software Amplify 3. Resulting amplicons were aligned using ClustalX 2.1; and
phylogenetic trees were obtained using NJplot. Species targeted are considered
pathogens in humans and animals. More than 50 pair of primers have been published
for amplification of mycoplasma's 16S rDNA. 60% are specific to strains, and 40% have
a broad target. Primer pairs demonstrated broader detection potential by means of 350,
1000, 1100, and 1500-bp amplicons. Thus, they were selected for further examination.
There was a similarity range from 100 to 68% overall, with greater average for the primer
set P3’Fw-P6’Rv ~1000-bp (84%).,Topology was similar for the four amplicons. Based
on this analysis, Deng and Hiruki’s primers are suitable to discriminate among diversity
enclosed sequenced genomes (the most robust information) of mycoplasmas.
Amplification efficiency of those primers will be examined among deposited sequences
in GenBank.
GENETIC POLYMORPHISM FOR ALKANE DEGRADATION PREVAILS ACROSS
ECOSYSTEMS IN PUERTO RICO
Yomarie Bernier-Casillas1,3; José R Pérez-Jiménez1,2,3
1
School of Science and Technology; 2Interdisciplinary Research Institute;
3
Puerto Rico Institute for Microbial Ecology Research, Universidad del Turabo
[email protected]
Alkanes are organic compounds that reach the environment by anthropogenic activities
and natural processes. Microbial degradation of alkanes contributes to bioremediation.
However, most studies have been conducted on polluted and temperate sites. Different
genes, encoding for alkane monooxygenases, participate in the degradation process,
such as alkB, alkB1, and alkM corresponding to Pseudomonas putida, Rhodococcus sp.
and Acinetobacter sp., respectively. Currently, we have isolated 77 putative alkane
degraders but the structure of the native community remains unclear. The objective is to
describe the community structure of aliphatic alkane degrading bacteria in response to
hexane, 2,2,4-trimethylpentane, and hexadecane. Soil samples were collected at ten
sites under contrasting pollution levels, including natural ecosystems, in Puerto Rico.
Native microbiota for each site was cultivated, as consortia, on rich media. The
community was described using 16S rDNA and alk based-TRFLP profiles generated
after digestion with HaeIII and HhaI. A total of 252 phylotypes were detected,
representing 114 different phylotypes, or richness, for 16S rDNA. Bacterial community in
contaminated sites ranged from 15 to 41, Bayamón River to Caño Tiburones,
phylotypes. Whereas in natural ecosystems oscillated between 19 and 27, Cabo Rojo
sands to salterns. Alkane monooxygenases genes, alk, were detected in 90% of the
study sites. Evaluation of clonal libraries is in progress to identify specific taxa. TRFLP
analyses have described distinctive bacterial diversity for every ecosystem despite its
contamination level, and disclosed a heterogeneous population putatively involved in
alkane degradation.
A-26
CONTROLLED SYNTHESIS OF Si NANOWIRES
Teresa Campo , Arancha Gómez1, Francisco Márquez2, Eduardo Elizalde1, Carmen
Morant1
1
Departamento de Física Aplicada M-XII, Universidad Autónoma de Madrid, 28049,
Madrid, Spain
2
[email protected]
Si nanowires (SiNWs) exhibit interesting properties with a wide range of mechanical,
electrical, electronic, optical, and chemical applications. They are considered one of the
most promising materials due to their enormous potential as building blocks for
nanodevices with relevant applications in energy. In this research, we present a
chemical procedure for the synthesis of SiNWs, with diameters of ca. 30 nm and lengths
of several micrometers. Monocrystalline Si (100) substrates, covered by a gold thin film
were used as support and as Si source. The nanowires were synthesized by thermal
treatment, without any additional Si source, at ambient conditions in flowing a mixture of
hydrogen and argon. A systematic investigation of the processing parameters has been
made, revealing that temperature, hydrogen flow rate, catalyst and substrate
morphology are critical for the growth of SiNWs. Additionally, we have shown that the
use of different coatings on the Si substrate improves the SiNWs growth. In this way,
TiN-coating induces the growth of vertically aligned SiNWs and the presence of silica
nanospheres-coating drastically increases the density of SiNWs. The synthesized
SiNWs have been characterized by FESEM and HRTEM microscopies, X-ray diffraction,
and X-ray photoelectron spectroscopy. As a result, it has been demonstrated that the
nanowires have a heterogeneous structure consisting of a Si core and an external
oxidized shell, indicating possibly that an VLS growth mechanism could be responsible
for the formation of this material. The surface morphology of the Si substrate clearly
affects to this synthetic process. Thus, we have demonstrated that selective SiNWs
growth is induced by local defects on the Si substrate. These defects are generated by
an indentation process which enhances the catalyst aggregation in the indented areas
and generates metastable Si, producing the SiNWs growth within indents. Additionally, a
selective growth of SiNWs has been successfully achieved by using external masks
during the physical deposition of the catalyst.
1
SYNTHESIS AND CATALYTIC ACTIVITY OF TIO2 NANOWIRES ON MODEL
ORGANIC COMPOUNDS
María Cotto1, Carmen Bonilla1, Abraham García1, José Ducongé1, Carmen Morant2,
Eduardo Elizalde2 and Francisco Márquez1
1
2
Department of Applied Physics M-XII, Autonomous University of Madrid, 28049 Madrid
(Spain)
[email protected]
The degradation of water sources and natural resources is actually one of the most
discussed issues. Organic, inorganic, bionutrients and microorganism are some of the
most common contaminants in water. The textile industry is one of the most
contaminant industries because dyes are nonbiodegradable compounds. Industrial
wastewaters that contain biorefractory compounds are normally limited to the use of
chemical treatments because the chemicals are toxic to the microorganisms used in the
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conventional biological treatments. Potential human exposure to wastewater which
contains dyes is a concern because are carcinogenic compounds, showing high
resistance against biological, physical and chemical reactions. The advanced oxidation
processes or AOPs have received great attention from researchers during the last
decades, because these processes can lead to complete mineralization of organic
pollutants. The use of photocatalytic materials is a common AOPs technique but the use
of the photocatalytic nanowires could be a new option for the degradation of
contaminants. One of the possible options is the use of titanium oxide nanowires as a
catalyst for the degradation of organic compounds. In this research, titanium oxide
nanowires (rutile phase) have been synthesized by hydrothermal method. The
nanowires have been characterized using scanning electron microscopy (SEM), X-ray
diffraction (XRD), infrared spectroscopy (FTIR) and UV-vis spectroscopy. Methyl orange
and rhodamine B were used as test molecules and their photodegradation has been
studied by UV-vis and fluorescence spectroscopies and total organic carbon (TOC)
analysis. By using titanium oxide nanowires as catalyst, the organic pollutants
experience a high degradation rate, reaching values between 93.55 % and 96.44 % for
methyl orange and rhodamine B, respectively. The results obtained during this research
demonstrated the efficiency of the process, pointing out to the possible use of rutile
nanowires in advanced oxidation processes.
SYNTHESIS AND CHARACTERIZATION OF GRAPHENE FLAKES TO BE USED IN
THE DEVELOPMENT OF ELECTRODES FOR LI-ION BATTERIES
M Cotto-Maldonado1, T Campo2, C Morant2, E Elizalde2, F Márquez1
1
Department of Chemistry and Physics, Universidad del Turabo, Gurabo, Puerto Rico,
USA
2
Departamento de Física Aplicada, Universidad Autónoma de Madrid, Cantoblanco,
Madrid, Spain
One of the main problems in our society is the energy production and storage. Ion-Li
batteries are commonly used as an alternative for energy production but have the
disadvantages of a poor recharged cycles and the possibility of fire. Researches are
done to develop efficient anodes and cathodes for batteries and one of the possible
alternatives is the use of graphene. Graphene is a single layer of sp2 carbon atoms. This
nanostructure has a two dimensional arrangement and the lattice looks like a
honeycomb having some relevant electronic, mechanical and thermal properties. Many
investigations are done in different areas as the use of graphene for heat conductor,
catalysis and sensors, high-power electronics and nanocomposites materials. During
this research, the preliminary synthesis of graphene over Cu substrate using a CVD
system was establish as part of one important investigation in the development of high
performance Li-ion batteries. The synthetized graphene was characterized by different
techniques including RAMAN, XRD, FE-SEM, SEM, TEM and EDX. As a preliminary
result a single and fine layer of graphene was synthetized. More research work is
necessary to develop a more efficient synthesis procedure.
HYDROGEN PRODUCTION BY WATER SPLITTING USING AU NANOPARTICLES
SUPPORTED ON TIO2 NANOWIRES
María Cotto1, Abraham García1, José Ducongé1, Carmen Morant2, Eduardo Elizalde2
and Francisco Márquez1
1
2
Department of Applied Physics M-XII, Autonomous University of Madrid, 28049 Madrid,
Spain
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[email protected]
The surface of the Earth’s crust receives more than 95 % sunlight in the range of visible
light (mostly 400-600 nm) and for this reason visible light driven photocatalysts have
been heralded as a crucial breakthrough in photocatalytic processes for water splitting.
In fact, from a practical point of view, the most important factor for applying the sunlight
absorption to water splitting for hydrogen production is the discovery of efficient and
stable photocatalysts. These photocatalysts are semiconductor materials consisting of
essentially an electron occupied valence band and an unoccupied conduction band.
This process has been regarded as a promising solution to resolve the global energy
and environmental problems. In this research, photocatalysts based on Au@TiO2
nanowires have been synthesized by hydrothermal approach. These catalysts were
obtained as layers of ca. 100 μm-thick, that were grown on the surface of
monocrystalline Si (100) wafers. The catalytic activity was measured by putting water
(with Na2S and Na2SO3 as sacrificial reagents) into contact with the Au@TiO2NWs
catalyst supported on Si wafers, at room temperature and atmospheric pressure. The
water splitting reaction was conducted in a quartz reactor equipped with a water-cooling
jacket. The reaction mixtures were irradiated at different light wavelengths (from 220 to
700 nm) using a solar simulator and appropriate cutoff filters in a static air atmosphere.
The evolved gases were analyzed by gas chromatography with a thermal conductivity
detector using N2 as carrying gas. The effect of the different synthesis parameters
(synthesis temperature, Au-Ti atomic ratio, and calcination temperature) on the
photocatalytic production of hydrogen has been studied in order to determine the best
experimental conditions. The catalysts have been characterized by X-ray diffraction
(XRD), scanning electron microscopy (SEM), and BET.
ARTHROPOD DIVERSITY AND DYNAMICS IN SECONDARY FORESTS IN THE
JOBOS BAY AREA, SALINAS, PUERTO RICO
SM Encarnación-Rodríguez1; MF Barberena-Arias1
1
The forests of Puerto Rico are disturbed by human activities, resulting in the formation of
secondary forests. These are rich in fauna and each one of them has a different
composition depending on the diversity of organisms among which arthropods can be
found. The importance of terrestrial arthropod biodiversity is due to their participation in
processes such as pollination, where bees move gametes from one flower to another,
and decomposition, where arthropods influence soil nutrient dynamics. As forests are
disturbed, arthropod diversity is threatened. As a consequence, the aim of this research
was to study arthropods in areas that represent sequential stages of vegetation cover
recovery. In this study, samples were collected at Jobos Bay, Salinas, using two
methods: active search combined with branch clipping and butterfly net. Data were
collected during dry and wet seasons from 2011 to 2013. The specific study areas were
abandoned areas that represent sequential stages of forest recovery: agricultural field, 5
y, 10 y, 15 y and 40 y forests, and a reference forest representative of the area:
mangrove. In the laboratory, collected arthropods were counted and identified to order.
Branch clipping and net were complementary methods because they collected
significantly different types of arthropods. A total of 4544 individuals were collected, that
represent 22 orders. Of these, 17 were common to all areas, and 5 were unique to
specific habitats. We found that abundance and richness of arthropods varied among
habitats and seasons. Coleoptera and Diptera were more abundant in the wet season
while Acari was more abundant in the dry season. The species composition of the
arthropod fauna varied among habitats, specifically the species composition of
mangrove arthropods was significantly different from all other habitats. Furthermore, the
A-29
abandoned agriculture area was different from the majority of other areas, and
sequential stages of recovery had sequential similarity in species composition. These
results suggest that the arthropod community is made up of common and unique
species that are present yearlong or only in specific seasons. Furthermore, mangroves
are unique habitats that harbor a specific arthropod community, while nearby forests in
sequential stages of recovery harbor sub groups of associated arthropods. As a
consequence, mangroves are sensitive areas that should be preserved because
associated arthropods are absent from recovering areas and any loss in mangrove cover
will negatively affect their survival.
ARSENATE RESPIRATORY REDUCTASE: BIOMARKER FOR DETECTION OF
ENVIRONMENTAL THREAT
Lirianys Figueroa Vélez and Jose R Perez-Jimenez
Arsenic is a toxic element found in nature, it affects human health by causing different
types of cancer, neurological and skin disorders. Arsenic is an odorless, colorless and
tasteless toxin capable of being dissolved in water. For these reasons arsenic species
are almost impossible to detect when present in food, water and gasses. Recent
discoveries have shown that some bacteria can transform arsenic species into more
toxic compounds through reductive mechanisms. Dissimilatory arsenate-reducing
prokaryotes, DARPs, respire arsenate, mobilizing arsenic into water. The nonFirmicutes DARPs represent several phylum in Chrysiogenes arsenatis, Geobacter
uraniireducens, Alkalilimnicola, Bacillus, Halanaerobiaceae sp. strain SLAS-1,
Sulfurospirillum arsenophilum, Shewanella sp. ANA-3, and Wolinella succinogenes. Our
goal is to strengthen screening tools with a new method in order to examine the
prevalence and diversity of DARPs in nature through the employment of bioinformatics
analyses. The prevalence of DARPs in nature is being assessed by the presence of the
arrA gene among microbial genomes. The arrA gene from Sulfurospirillum barnesii was
subjected to blast analyses among 1470 non-Firmicutes genomes. So far, highest
homology was found for three genomes: 71 % for Wolinella succinogenes, 74 % for
Shewanella putrefaciens, and 74 % for Shewanella sp. ANA-3. Shewanella species
demonstrated large centers of divergence in the middle, ~80% coverage. Less
homology was detected at nucleotide level than the amino acid sequence. The
arrAgenes are highly divergent to find sites that flank central islands of difference to
support a new detection method. Conserved sequences are useful biomarkers to
ascertain prokaryotes capable of arsenate respiration; this will allow us to monitor the
risk of arsenate mobilization in nature.
NEW PHOTOCATALYSTS FOR HYDROGEN PRODUCTION
Abraham García, María C Cotto, José Ducongé, Francisco Márquez
Nanomaterials Research Group, Escuela de Ciencias y Tecnología, Universidad del
[email protected]
Photocatalytic water splitting with generation of hydrogen is a green process that
concerns activity of a semiconductor material under sunlight irradiation and ambient
pressure and temperature. This process has been regarded as a promising solution to
resolve the global energy and environmental problems. Hydrogen generation by water
splitting (H2O(l)→H2(g)+1/2O2(g)) has been studied on photocatalysts based on Zn, Cd, Fe
and Cu, synthesized by coprecipitation. Fe nanoparticles were incorporated as
cocatalyst to enhance the photocatalytic activity of the ZnCd solid solution. The effect of
the different synthesis parameters (temperature, dispersion, and calcination
A-30
temperature, among others) on the photocatalytic production of hydrogen has been
studied in order to determine the best experimental synthesis conditions. The catalysts
have been characterized by X-ray diffraction (XRD), scanning electron microscopy
(SEM), X-ray photoelectron spectroscopy (XPS) and BET. The experiments of
photocatalytic water splitting were performed in aqueous solution of the photocatalyst
previously dispersed in a soft ultrasound bath. The photocatalysts were irradiated under
different lights ranging from 220 to 700 nm. The rate of hydrogen production has been
correlated with the BET area and dispersion degree.
YEAST INVOLVED IN THE DEGRADATION OF PLANT RESIDUES AS A
POTENTIAL BIOFUELS SOURCE
Jean García-Díaz1,3, José R Pérez-Jiménez1,2,3
1
School of Science and Technology; 2:Interdisciplinary Research Institute; 3:Puerto Rico
Institute for Microbial Ecology Research, Universidad del Turabo, Gurabo, Puerto Rico
The efficient degradation of organic matter into useful biofuels is currently seen as the
best alternative to fossil fuels. Anaerobically, strains of Saccaromyces cerevisiae and
Pichia stipitis degrade plant residues, lignocelulosic materials, into ethanol. Our goal is
to isolate lignocellulosic degrading yeasts from decaying organic matter. Samples were
collected from several endemic tree barks collected at El Yunque National Forest and
general decomposing plant residues in stagnant water on Universidad del Turabo.
Samples were cultured in malt extract broth medium, and complex selective YPD
medium with kanamicin. Isolates were inoculated on Yeast Carbohydrate Fermentation
Broth to assay for the fermentation of xylose. After 48 hours of incubation, samples were
purified on plates with the same media and incubated until growth could be seen.
Preliminary results have shown growth of microorganisms in both selective media and
xylose fermentation in at least two samples. Approximately 30 microorganisms have
been isolated. Closest homologs are found among Candida rugopelliculosa,
Cryptococcus flavescens, Cryptococcus laurentii, Pichia occidentalis, Rhizomucor
variabilis, Rhodotorula mucilaginosa, Tremellales sp., Wickerhamomyces subpelliculosa,
and Williopsis saturnus. Test for lignocellulosic degradation are in the process. Further
molecular characterization using the xylose reductase gene XYL-1 will help in the
identification of xylose fermentative pathways. This research will provide views on the
yeast diversity for developing biofuels.
MICROSPHERES FOR THE GROWTH OF SILICON NANOWIRES
A Gómez-Martínez*1, F Márquez2, María Cotto2, E Elizalde1, C Morant1
1
Depto. de Física Aplicada, Universidad Autónoma de Madrid, Cantoblanco 28049
Madrid, Spain
2
*[email protected]
Silicon nanowires (SiNWs) have recently gained great interest as an alternative to
carbon materials as carbon nanotubes or graphite. One-dimensional silicon structures
are particularly attractive because of their mechanical, optical and electrical properties.
Nowadays, a number of applications are being investigated for such SiNWs, including
intensive blue light emitters in integrated optics, field effect transistors and sensor
applications. There is also growing interest in the use of SiNWs on energy storage
devices, in particular as active material for the anode of lithium ion batteries because
silicon has the highest known theoretical specific capacity (higher than 4200 mAh/g).
In this work, we present a simply procedure for the growth of nanowires via a thermal
process at 900 oC in H2 and Ar atmosphere. The details of this method have been
A-31
previously reported [1]. Two different micro-sized spheres (silica and carbon) were used
as innovative supporting material for the growth of the SiNWs. These spheres were
synthesized in our laboratory, through a hydrolysis process for silica spheres [2] and via
a route of dehydration and subsequent condensation of sucrose, in the case of carbon
spheres [3]. These microspheres were deposited on silicon surfaces, then they were
coated with Au (10nm thickness) and subsequently, the growth of SiNWs was carried
out. The same silicon wafer was used as both substrate and solid silicon source. The
synthesized SiNWs have been fully characterized by FESEM and HRTEM microscopies,
X-ray photoelectron spectroscopy and EDX analysis.
HISTORICAL SEASHELL AND BONE USE BY THE NATIVE INDIGENOUS THAT
INHABITED THE PRESENT CABEZAS DE SAN JUAN AREA, FAJARDO, PUERTO
RICO
Viviana Gonzalez Colón1, Karen M. Ocasio Pérez1, Carlos Pérez Ph.D2, María Fernanda
Barberena-Arias1 Ph. D.
1
:Universidad del Turabo, School of Science and Technology, Gurabo, Puerto Rico
2
: Instituto de Cultura Puertorriqueña
The shores of the “Cabezas de San Juan” reserve in Puerto Rico are rich in historical
artifacts and food waste left behind by the native indigenous tribes that once inhabited
them. As part of an archeological excavation, a parcel was established where samples
were taken at consecutive varying depths. Our goal is to study how seashell and bone
quantities vary at different depths of the vertical profile previously established, and to
understand what these quantities reveal to us about the pre-existing indigenous
population. We worked with samples taken in the summer of 2012 by the archeological
team. We cleaned and separated them into respective groups: seashells and bones.
Once the samples were separated, we counted the items present in each group and
logged the numbers. We were able to observe that the quantities of bones and seashells
varied at different depths. It is important to understand the way indigenous people lived
and survived because it is through this understanding that we can appreciate the extent
of the changing lifestyle in Puerto Rico over the centuries. Meanwhile, we will learn
whether already extinct species were native or introduced. With future classifying of
bones and seashells, we can learn about hunting styles, capturing techniques, dietary
habits and preferences, and the physical capabilities of the indigenous population.
BACTERIA: BIOINDICATORS OF HEAVY METALS AND THEIR IMPACT ON THE
HUMAN COMMUNITIES AND THE ECOSYSTEM
Hector Orozco-Mercado2; Melanie De La Rosa1; Johannys Jiménez2; Karlo MalaveLlamas1; Juan C. Musa3
1
School of Science and Technology, URGREAT-MBRS-RISE, Universidad Del Este,
Carolina, Puerto Rico
2
School of Science and Technology, Universidad Del Este, Carolina, Puerto Rico
3
School of Environmental Affairs, Universidad Metropolitana, San Juan, Puerto Rico
[email protected]
In high concentrations, Heavy Metals exposure has been associated with neurological
disorders, motor skills, bone density, sturdiness, and learning problems. Puerto Rico is a
tropical island with many natural resources; one of those resources is “Las Cucharillas”
Marsh. This site is composed of interconnected wetlands, and water bodies that pass
through eight of the most populated and polluted municipalities of PR, with heavy metals
like; Al, As, Cd, Cr, Cu, Fe, Hg, Mg, Pb, and Zn. People in the vicinity are in high risk of
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exposure. Various microbial species, especially bacteria, had been proposed as
bioindicators and as mitigation strategies of heavy metal contamination. Our study
pretends to exploit the sensitive nature, of some bacteria, to heavy metals; with the
objective to assess the bacterial community on the mangrove marsh and correlate
bacterial species with the type and concentration of the metals found. First, sediment
samples were taken to a local laboratory to determine a bacteriological baseline of the
number of bacteria present on the marsh. Data reveled a total of 1790 CFU of Total
Coliform Bacteria and 996 CFU of Fecal Coliform Bacteria, with a p-value of 0.003
demonstrating a significant difference between the bacterial compositions on the site.
Following this initial assessment, bacterial species were identified using the BIOLOG.
Among the species were Ralstonia picketti, Cupriavidus gilardii, Microbacterium
flavescens, Enterococcus maloduratus and Carnobacterium inhibens. The data collected
in this project will help us to have a baseline for future research.
Supported by: US-Forest Service 11-DG-11330101-110 and URGREAT-MBRS-RISE
5R25GM066250 and UNE.
TEACH ENVOIS: UN ESTUDIO DE CASO EN EDUCACIÓN AMBIENTAL EN
PUERTO RICO
Eddie N Laboy-Nieves1, Abniel Machín De Jesús2
1
Eddie N. Laboy-Nieves – Catedrático de la Escuela de Ciencias y Tecnología de la
Universidad del Turabo y Director del Departamento de Ciencias Ambientales
2
Abniel Machín De Jesús – Estudiante de Maestría del Programa de Ciencias
Ambientales de la Escuela de Ciencias y Tecnología de la Universidad del Turabo
[email protected]
Veinticinco maestros participaron en un programa de talleres y adiestramientos para
poner a prueba sus conocimientos sobre la fauna, conceptos ambientales, y técnicas de
publicación en Internet. Las respectivas pruebas diagnósticas revelaron que más del
80% de los participantes obtuvieron puntuaciones promedios deficientes de 17.3, 56.3 y
63.9 %. Después del adiestramiento a través del Proyecto TEACH-ENVOIS, más del 80
% de los maestros calificaron en niveles superiores de aprovechamiento, tras obtener
puntuaciones superiores a 85% en las post pruebas. Estos resultados fueron
interpretados como indicadores de asimilación y adquisición de nuevos conocimientos y
destrezas por parte de los participantes. Los maestros desarrollaron videoclips de corta
duración para complementar el contenido de las clases. Estos cortometrajes enfocaron
problemáticas ambientales de la comunidad, por lo que requirió aunar esfuerzo de
colaboración y concienciación con los estudiantes, y miembros de la comunidad. Nueve
producciones fueron publicadas en Internet. Evaluadores externos revisaron y
calificaron los proyectos, otorgándole un 89.7 % en general. Se concluyó que la
estrategia utilizada promovió alianzas simbióticas que a la postre permitirán reforzar,
mejorar e implementar programas de educación y manejo ambiental en Puerto Rico
desde una base de participación comunitaria.
DEVELOPMENT OF HYPERBRANCHED SILICON NANOWIRES FOR
PHOTOVOLTAIC APPLICATIONS.
Francisco Márquez1, Annette Malavé1, Abraham García1, María Cotto1, José Ducongé1,
Teresa Campo2, Arancha Gómez2, Sergio Pinilla2, Eduardo Elizalde2 and Carmen
Morant2
1
Nanomaterials Research Group-NRG, School of Science and Technology, Universidad
del Turabo, 00778PR, USA
A-33
2
[email protected]
The need of alternative energy sources has recently become a priority. The increasing
demand of energy, the alarming increase of greenhouse gases emission and the
variability of oil prices, have driven the need for clean and renewable energy. In this
situation we find in the sun a great ally, solar PV is on the verge of achieving the priceper-watt needed to become a competitive energy source. That is why profitability is as
important as efficiency, so Silicon is our greatest asset. Joining the great development of
silicon technology and new and great possibilities that nanotechnology holds, we can
take the final leap necessary to become photovoltaic energy a competitive and profitable
source of energy. The main goal of this research has been the synthesis of a
nanostructured silicon surface capable of a high reduction of the reflectance, using an
inexpensive and scalable method. For this purpose, hyperbranched silicon nanowires
(HbSiNWs) have been prepared on monocrystalline Si (100) wafers by using an acid
etching method. This method involves etching of silicon wafers in a silver nitrate and
hydrofluoric acid based solution. We have studied different parameters of this growth
and its effects over the specific area and reflectivity. The HbSiNWs have been
characterized by SEM, BET, and XRD. As a result, we have obtained HbSiNWs with
very low levels of oxygen and specific areas ranging from 350 to 500 m 2 g-1. This
material could have important applications in energy, including its use for reducing the
reflectivity in photovoltaic solar panels.
CASE STUDY: ANALYSIS OF WEATHER CONDITIONS AND SMOKE FOR 2002
BISCUIT FIRE IN SOUTHWEST OREGON
ME Martinez1; B Potter2; SM O’Neill2
1
Graduate School of Science and Technology, Universidad del Turabo, Gurabo PR; 2US
Forest Service AirFire Team, Seattle WA
[email protected]
A series of lightning storms ignited five fires in the Siskiyou Mountains in Southwest
Oregon starting on July 13, 2002. Within days the fires joined together. The fire burned
for two months across almost half a million acres of wildland and communities.
Estimated cost to control and suppress the fire amounted to $150 million and a work
force of more than 7,000 people constructed over 400 miles of fireline in order to control
and suppress the fire. An analysis of the weather conditions and the smoke emissions
from the Biscuit Fire was performed in a two-phase case study research. First, a
meteorological reconstruction of the weather observed during the fire event was
accomplished. This analysis took into consideration available synoptic analyses,
mesoscale meteorological data, and on-site meteorological observations during the fire.
Second, a re-creation analysis of the smoke behavior, emissions and effects was
performed through the use of the BlueSky Smoke Modeling Framework and the Hybrid
Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) dispersion model. The first
phase analysis included collecting detailed information regarding the fire location, fire
progression, and growth, enabling the creation of three different ignition pattern
scenarios. The detailed fire progression analysis was used as input to BlueSky, to
investigate how greater detailed fire ignition and progression information impacts smoke
concentrations near surface and aloft. This analysis is intended to clarify the variability
and uncertainty in emissions impacts resulting from uncertainty in input variables and
model assumptions. Results will aid managers on the planning of strategies to protect
health, life and properties.
A-34
PHYCOLOGICAL CULTURE OPTIMIZATION FOR THE PRODUCTION OF FUEL
OILS
Abisrael Morales Feliciano1,3; Jean García-Díaz1,3; José R Pérez-Jiménez2,3,4
1
Science and Technology School, 2Department of Biology, 3Puerto Rico Institute for
Microbial Ecology Research,4Interdisciplinary Research Institute, Universidad del
Turabo, Gurabo, Puerto Rico, USA
[email protected]
In the last decade scientist have been looking for another energy source that is less
harmful to the environment than fossil fuels, while reducing emissions of greenhouse
(GHG’s). These are responsible for the warming in the earth's atmosphere known as
global warming. With the emerging need to reduce these GHG’s microalgae has been
proposed as an alternative to the production of biofuels. Our objective is to optimize the
lipid production in four strains of algae; Isochrysisgalbana, Nannocloropsisocculata,
Botryococcusbraunii, and Chlorellavulgaris. These algal strains have been observed to
contain between 20 % - 50 % lipid content in a native environment which makes them
ideal candidates for optimization. It has been observed that certain critical parameters
can obstruct or augment algal growth rates. These parameters include pH levels, light
wavelength, medium nutrient composition, and physical growth conditions. We observed
direct effects on growth rates and lipid production when variations to these parameters
were altered. Growth curves were plotted to analyze change in optical density. Glucose
addition to the media in a concentration of 2.5 g L-1 increased the growth level 15 times
on
Botryococcusbrauniiand
induced
a
prolonged
adaptation
phase
in
Nannocloropsisoculatawith minimal growth. Medium was also supplemented with waste
fluids from a cheese production factory which sustained algal growth.
Isochrysisgalbanaand Chlorella vulgaris displayed variable growth levels which may
result when aggregates form exopolymers in more mature culture to be elucidated by
microscopically examination. Assays on solid medium displayed prolonged growth rates
on all algae strains. Which demonstrates the microalgae’s capacity to adapt to varying
environments.
PRODUCCIÓN DE BIODIESEL A PARTIR DE ACEITES VEGETALES
DM Ortiz-Rodríguez; F Márquez-Linares
Turabo
[email protected]
Uno de los principales objetivos de la comunidad científica actual es encontrar fuentes
alternativas de energía para reducir el consumo excesivo de los combustibles fósiles. La
producción de biodiesel es una alternativa viable, económica y respetuosa con el medio
ambiente para reducir las emisiones nocivas a la atmósfera. El biodiesel puede ser
producido por medio de la reacción de transesterificación de un aceite vegetal nuevo o
usado (por ejemplo de girasol, maíz u oliva) con un alcohol de cadena corta (metanol)
en presencia de un catalizador (NaOH). Para garantizar la calidad del biodiesel
sintetizado, se realizaron varias pruebas de calidad: metanol, agua, pH, viscosidad y
pruebas de eficiencia realizadas en un motor diesel. Los resultados obtenidos indican
que el biodiesel de aceite de girasol fue el de mejor eficiencia, seguido por el de maíz y
el de oliva. Las emisiones de CO2 que podrían afectar el medio ambiente fueron
menores de 4.1 % para los tres aceites considerados.
GENE ANNOTATION AND CHARACTERIZATION OF REARRANGEMENTS IN THE
EVOLUTION OF THE PUERTO RICAN PARROT (AMAZONA VITTATA)
A-35
Edwin G Ramírez-Aponte1, Jennifer Hernández-Muñiz1, Michelle A Vega-Medina1,
Adriana Gordon-De Jesús1, Gustavo Rivera-Álvarez1, Ghildres Tejedor -Maldonado1,
Ingrid Rivera-Pagán1, Taras K Oleksyk1 and Juan C Martínez-Cruzado1
1
Department of Biology, University of Puerto Rico at Mayagüez
[email protected]
The Puerto Rican parrot (Amazona vittata) is the only native parrot species in Puerto
Rico and the last one remaining in any of the U.S. territories. It was listed as an
endangered species in 1967 and in the early 1970s its population diminished to 13
individuals. Its critical condition promotes the development of many conservation
projects; one of them is the Puerto Rican Parrot Genome Project. This species became
the first bird of the genus Amazona to be sequenced. Its genome data has recently
become publicly available thanks to the community effort of the people of Puerto Rico,
and the annotation of the parrot chromosomes has begun. To advance the description of
the protein-coding genes and other important protein and gene features, we are focusing
on
chromosomes
8
and
9
from
the
latest
genome
assembly
(http://genomes.uprm.edu/parrot). To do this, we used as reference the chicken (Gallus
gallus), zebra finch (T. guttata), turkey (Meleagris gallopavo), collared flycatcher
(Fidecula albicolis), budgerigar (Melopsittacus undulatus), and scarlet macaw (Ara
macao) genomes. Some annotation resources and tools used for this work are: Standalone Blast, Blast from NCBI, UCSC Genome Browser, Gene Model Checker, Ensembl,
MEGA 5, and Repeat Masker. We already found and fully annotated 115 genes in 8 of
the sequences provided by the genome assembly. The length of the completed analyzed
sequences adds to 9.8Mb. Another 10.5Mb coming from 7 different sequences are in the
process of annotation. These results allow us to see the conservation of genes
throughout evolution and to create a model of the Puerto Rican parrot chromosomes.
Also the knowledge retrieved from these genes should provide conservationists and
geneticists with a more thorough understanding and ways they can improve the
conservation efforts.
ENVIRONMENTAL MANAGEMENT OF POLYCYCLIC AROMATIC
HYDROCARBONS (PAHs): A CASE STUDY FOR SYSTEM APPROACH
Yolanda Ramos-Jusino and Anastacio Emiliano-Sosa
[email protected]
It was proposed that T. recurvata sp was a cost-effective alternative to develop a
monitoring grid for PAHs from transportation in PR for regulatory purpose. That this was
an effective alternative to overcome the limitations of high costs of traditional sampling.
After an experiment was performed including sample collection, preservation,
preparation, and extraction, and Gas Chromatography Mass Spectrometry analysis; the
conclusion was that the original hypothesis was wrong. Compliance driven
measurements, although adequate for gross descriptions of the extent and types of
contaminants found at a site, are largely insufficient to address the questions
fundamental to an environmental compliance investigation. PAHs are one complex
mixture of toxic pollutants that interact to produce adverse effects, as reduced IQ,
behavioral disorders, diabetes, cardiovascular disease, cancer, infertility, oxidative
stress and increase susceptibility to other stresses. Dealing in isolation with PAHs from a
non-point source can be very costly and of limited benefits. Nonetheless knowledge on
their abundance may support robust environmental management plans throughout a
system approach that in overall protect from risks associated to diverse groups of
complex mixtures in which PAHs coexist. Environmental management is concerned with
systems that have a particular high complexity but historically environmental quality
A-36
control, focused on acute effects, dilution and removal of pollutants with end of pipe
technologies. System thinking in contrast, seeks to understand the complex interactions
between social, natural, and built environmental systems, conditions and policies that
impact human health and well-being. It deals with long-term effects of low level
exposures. This dissertation shows through a literature review, focused in the exposures
and effects of PAHs, the need of a system thinking approach in environmental
management. Common and potential serious sources of PAHs are explored. The review
could be used by different groups of professionals and the general community to
manage the exposure to PAH and enhance the overall resilience to their effects. A team
that is coping with a major environmental health problem may include scientists,
physicians, epidemiologists, engineers, economists, lawyers, mathematicians, and
managers. Input from experts in these and related areas is essential for the
development, application and success of the control strategies necessary to encompass
the full range of people’s lifestyles and their environment. Environmental specialists and
all other disciplines specialists come from universities that prepare them to deal with
problems of their field in isolation. There is a need for the social role of an environmental
administrator to integrate activities from several natural sciences with several of the
social sciences. The continuous challenge to keep environmental pollution under control
shall provide options to minimize exposure and strengthen the body’s ability to defend
itself against the negative factors in the environment.
USING REAL-TIME WATER QUALITY DATA TO STUDY THE HYDROLOGY NEAR
FORT BUCHANAN, PUERTO RICO
Ronald T Richards and Anastacio Emiliano
Univerisdad del Turabo
[email protected]
The United States Geological Survey is operating two real-time water quality stations
near Fort Buchanan, Puerto Rico. Both stations are small surface streams that drain
forests, houses, offices, a golf course, commercial buildings, and parking lots. Quebrada
Santa Catalina near Guaynabo (50048565) and Unnamed Creek at Fort Buchanan,
Guaynabo (50048580) have data of temperature, specific conductance, pH, and
dissolved oxygen every 15 minutes. Quebrada Santa Catalina also has gage height. The
data are sent to the Internet via satellite every hour. The Pearson correlation coefficient
between temperature and gage height is -0.23. The correlation between specific
conductance and gage height is -0.74. Both sample sizes are over 5000 and are
statistically significant. The rains in the afternoon show a significant interaction with the
land surface heated by the Sun. The relationship between specific conductance and
gage height shows the curve typical of the two-water mixing model. The diurnal
temperature cycle of Quebrada Santa Catalina is 0.46 °C versus 2.11 °C for Unnamed
Creek. This is evidence that the water in Quebrada Santa Catalina has recently been
discharged from a spring. At some times, Unnamed Creek has evidence of
photosynthesis occurring in the water. The water quality signature of photosynthesis is a
diurnal cycle in both pH and dissolved oxygen where both peak in the afternoon. The
water quality signature of photosynthesis is not present in Quebrada Santa Catalina.
SULFIDOGENIC ASSEMBLAGES ALONG LIFE ZONE AT EL YUNQUE RAIN
FOREST IN PUERTO RICO
Edaris Rodríguez Izquierdo1,3, José R Pérez-Jiménez1,2,3
1
:School of Science and Technology; 2:Interdisciplinary Research Institute; 3:Puerto Rico
Institute for Microbial Ecology Research, Universidad del Turabo, Gurabo, Puerto Rico
A-37
Sulfate-reducing bacteria (SRB), prevailing in anoxic sites, have been detected on
terrestrial habitats with limited perspectives on diversity and distribution. Five life zones
in El Yunque tropical rain forest (tabonuco, palm, elfin, dry, and colorado forest) are
developed in an elevation gradient subjected to natural disturbances physicochemical
conditions. Our goal is to describe the structure and distribution of SRB throughout life
zones in the rain forest. Soil samples were collected during June and December 2005
from plots at two depths (0-5 cm, 5-10 cm). Total genomic DNA was extracted for
amplification of the dissimilatory sulfite reductase gene (dsrAB) and terminal restriction
fragment length polymorphisms (TRFLP) analysis. A diverse sulfidogenic community is
comprised by 451 TRF (representing 371 phylotypes) among the set of samples
analyzed. Heterogeneity of sulfidogenic communities, represented by unique TRF, is
evident among forest: Tabonuco (2.3 %), palm (35 %) and elfin (18 %). The dsrAB
cloned from the elfin forest were phylogenetically diverse, with closest similarity to
Desulfobacca acetoxidans and Desulfomonile tiedjei. Sorensen’s similarity Index,
demonstrated approximately 29 % of similarity between palm and elfin forest
sulfidogenic communities and 16 % when we compare both with Tabonuco. The
sulfidogenic communities across the elevation gradient are rich, with diverse
distributional patterns that could contribute to the natural history of the ecosystem. SRB
seems to thrive within the saturated soils of the forests with a potential role on
decomposing complex substances from decaying trees. The dsr-TRFLP has provided
insights about the phylogeography of SRB in Yunque that may be useful to understand
their natural activities.
PHARMACEUTICALS AND PERSONAL CARE PRODUCTS IN NATURAL
ENVIRONMENTS
L San Miguel-Rivera1
Doctoral Candidate, School of Science and Technology, Universidad del Turabo
[email protected]
The occurrence and fate of pharmaceutical and personal care products (PPCPs) in the
environment is a matter of recent concern. As health products, medicines are designed
to be biologically active to interact with target organs to improve public health and quality
of life. After usage many drugs are excreted as metabolites or conjugates with different
properties than the parent compound. The impact of these products and their effects in
the environment has been studied in different scenarios. Pharmaceutical products are
widespread pollutants and their continuous use adds detrimental residues that can enter
in the environment via water and soil pathways. Scientific evidence of traces in
wastewater, surface water and groundwater as well represents a potential threat to
essential organisms through the food chain. The massive use of them by the world
population and the incorrect disposal of unused expired or discarded medicines simply
provide another perspective on handling this issue. The unceasing population growth
demands drinking water without contaminants. PPCPs have two main concerns: the
human health implications of antibiotic resistance bacteria that raise the treatment cost
and the no regulation for the pharmaceuticals in the environment. To minimize the
PPCPs in the ecosystems is need environmentally friendly chemicals, reduce the
overuse, decrease the inappropriate use and adopt appropriate disposal practice to
prevent the human exposure to these contaminants through the drinking water and
protect the environment.
CATALYTIC PHOTODEGRADATION OF P-AMINOBENZOIC ACID ON TIO2
NANOWIRES WITH HIGH SURFACE AREA
A-38
Pharmaceutical personal care products (PPCP’s) production and consumption have
increased exponentially in recent years due to medicine and technological advances
associated with dangerous skin illness such as cancer. These PPCP’s usually are found
in wastewaters and their removal represents a complex environmental issue.
Conventional water treatments have proved to be insufficient to remediate contaminated
waters with PPCP’s. With the aim of studying the possible degradation of these
compounds, we have synthesized TiO2 nanowires (rutile phase) using TiCl4 as
precursor. The synthesis was carried out by a hydrothermal process in an acidic
medium.
The synthesized catalysts were fully characterized them by BET
measurements, XRD and SEM-EDS analysis and used in the photodegradation reaction
of p-aminobenzoic acid (PABA). The photocatalytic degradation of PABA has been
studied under different experimental conditions (i.e. catalyst loading). The photocatalytic
reaction was monitored as a function of time by UV-Vis and fluorescence
spectroscopies. The highest degradation rate occurred with 1.0 g L-1 of catalyst while
the reaction does not proceed without radiation or in absence of the catalyst. The
present work demonstrates that p-aminobenzoic acid could be successfully degraded in
a relatively short time period with high degradation percentages.
FOTODEGRADACIÓN CATALÍTICA DE ÁCIDO P-AMINOBENZOICO MEDIANTE
NANOPARTÍCULAS DE ZNO
La presencia de contaminantes en sistemas de purificación de aguas (por ejemplo,
productos farmacéuticos de cuidado personal) resulta especialmente alarmante. Entre
estos productos farmacéuticos se encuentran los filtros solares, que se bioacumulan en
la aguas debido a su resistencia a la degradación, incluso en ambientes muy expuestos
a la radiación solar. En esta investigación se ha estudiado la fotodegradación catalítica
del ácido p-aminobenzoico (PABA), que fue extensamente utilizado durante la década
de los 70’s. Para ello, se sintetizaron nanopartículas de ZnO (ZnO NPs) que fueron
caracterizadas mediante SEM, EDS, DRX y medidas de área superficial. Las ZnO NPs
fueron utilizadas como catalizador en la fotodegradación de PABA. Para el proceso de
fotocatálisis se emplearon concentraciones de ZnO NPs desde 0.4 g L-1 hasta 1.2 g L-1,
con una concentración de PABA de 5.0 x 10-5 M y a pH=3. Mediante espectroscopias
UV-Visible y fluorescencia se comprobó que PABA puede ser degradado mediante
procesos fotocatalíticos, empleando una fuente de radiación convencional. Estos
resultados sugieren que ZnO NPs podrían ser eficientemente utilizadas para procesos
de descontaminación ambiental.
METAL POLLUTION OF LAKE SEDIMENTS IN SOUTHWEST OHIO
Stella Castro1, Mark Krekeler2
1
Universidad Metropolitana, Recinto Cupey
2
Miami University, Ohio USA
[email protected]
Metal pollution impacts global ecosystems and potentially human health through fish and
water fowl consumption as well as atmospheric exposure. Ohio has high concentrations
of pollution coming from industrial and agricultural activities. This investigation is the first
A-39
detailed survey of metal pollution in lakes of southwest Ohio utilizing inductively coupled
plasma- mass spectroscopy (ICP-MS), electron microscopy and X-ray diffraction. A total
of 46 samples from the upper 2 cm of sediments from 12 lakes were investigated.
Samples are dominated by mineralogy of illite, chlorite, quartz and calcite. The chemical
index of alteration values indicates moderate weathering. Combined the bulk major
element chemistry and mineralogy suggest a typical geologic source for the sediment.
For the majority of samples concentrations of Cu, Zn, V, Sn, Co, Sb, and As were higher
than that of the geological background. Some correlations between metals such as Cu
and Zn, Co and Sn, Cr and Sn were observed suggesting multiple sources of pollution.
The electron microscopy indicates coal combustion particulate pollution such as
micrometer-scale spherules and barite occurs in some samples. Nickel rich-particles
were also observed. Limited scanning transmission electron microscopy – energy
dispersive spectroscopy mapping at the nanoscale indicates that nickel is dispersed on
illite particles. The absence of abundant particulate suggests that the pollutants are
adsorbed by the mineral fraction and very dispersed throughout the clay surface. No
correlation is observed between pollutant metal concentrations and land use designated
as agricultural, forested and urban or carbon, nitrogen and phosphorous and
sedimentation rate parameters. This suggests that the rate of the atmospheric deposition
of pollution is much greater than the pollution coming from urban particulate in overland
flow for these lakes. The major source of pollution is interpreted to be from atmospheric
sources such as traffic emissions and coal combustion. Coupling electron microscopy
and bulk chemical analysis enables source interpretation. This investigation illustrates
unrecognized complexity in metal pollution in southwest Ohio and demonstrates the fate
and transport of atmospheric metal pollution into lake systems.
SUMMER BIRDS: SPECIES RICHNESS AND DIVERSITY OF RESIDENT BIRDS IN
SOUTHEASTERN PUERTO RICO
Waleska Vázquez-Carrero and Fred Schaffner PhD
[email protected]
Habitat selection on the wintering grounds and stop-over areas is crucial for migratory
bird survival and for a successful migration. Vegetation features can influence resource
availability for birds, an important factor affecting habitat selection. Comparing two sites
with distinct degrees of disturbance and successional stages, abundance, species
richness, and diversity of avian communities were evaluated in relation to general
characteristics of each site. For this, fixed-radius point counts and mist netting were
used in order to quantify bird presence and fitness (body condition index, BCI). To
assess body condition and possible interactions within habitat, special focus was placed
on resident Bananaquit (Coereba flaveola), a sedentary species (known to roost in their
foraging habitat). Preliminary results from the Non-migratory Season (NM, May-August)
show higher diversity and number of species present for one of the sites, S2: a mixed
secondary forest. Additionally, BCI for Bananaquits varied between sites, also when
including the “Dry Migratory” season (M2, January-April). With this information, habitat
use and quality can be evaluated so as to establish better conservation plans for
migratory and resident birds, bringing additional information for the restoration and
conservation of favorable spaces.
DEVELOPMENTAL EXPOSURE OF DROSOPHILA MELANOGASTER TO LEAD
(PB2+) RESULTS IN ALTERED GENE EXPRESSION OF GENES INVOLVED IN
SYNAPSE FORMATION AND FUNCTION IN THE LARVAL BRAIN.
A-40
Amneris Hernández-Figueroa1, Beatriz Cardona4, Guillermo Delgado4, Francheska
Merced4, Zoé Márquez4, Norma Rodríguez1, Agosto-Alicea José L.1, Sandra Peña de
Ortiz1, Adrinel Vázquez Montes4, Humberto Ortiz-Zuazaga2,3
1
Department of Biology, 2Department of Computer Science and 3High Performance
Computing Facility, University of Puerto Rico, Rio Piedras Campus. 4School of Science
and Technology, University of Turabo.
Lead (Pb2+) is an environmental toxicant that has been potentially linked to several
neuropathologies including Attention and Hyperactivity Deficit Disorder (ADHD),
aggressive and antisocial behaviors, and Autism Spectrum Disorders (ASD). Recent
studies have argued that Pb2+ developmental exposure could interfere with normal
genetic expression patterns in the immature brain by alterations in calcium metabolism
and synaptic function. However, the precise molecular mechanisms underlying the
neurotoxicity of developmental Pb2+ exposure are still to be elucidated. Our overarching
hypothesis is that Pb2+ impairs normal developmental gene expression and central
nervous system development leading to behaviors modeling pervasive developmental
disorders, such as autism. We have established in previous studies that developmental
lead exposure to D. melanogaster produces social interaction deficits and delays in the
developmental cycle of this model organism. In order to gain insight into the cellular
mechanisms affected by exposure to this toxicant, we collected RNA samples from larval
brain extractions of control and Pb2+-exposed flies and performed cRNA hybridization on
a 4x44K Agilent microarray. Our preliminary results reveal a significant upregulation of
genes belonging to the membrane associated guanylate kinases (MAGUKs) family,
which are scaffold proteins with essential roles in synapse development and function.
Interestingly, mutations of MAGUKs are linked to a number of human diseases, including
ASD. With this preliminary molecular “fingerprint”, we propose that molecules related to
synapse formation and function may be potential targets of Pb2-mediated developmental
neurotoxicity. Supported by P20-RR016470.
CAFFEINE AS A TROPICAL WATER QUALITY INDICATOR TO ASSESS THE
IMPACT OF WASTEWATER AND SURFACE WATER
EC Villafañe-Deyack1, E Resto2, C Lozano1
1
Escuela de Ciencias y Tecnología, Universidad del Turabo; 2Universidad de Puerto
Rico, Recinto de Río Piedras
[email protected]
The research primary goal was to identify and evaluate anthropogenic pollution sources
affecting bathing zones of Puerto Rico using caffeine as a water quality indicator. Three
sources were identified: 1) wastewater-septic wells, 2) adjacent surface water bodies,
and 3) storm water discharge. A pilot study was performed on 23 Beaches analyzing
eight (8) years of microbiological data to evaluate compliance. The pilot project results
indicate higher violation to enterococci parameter than to fecal coliform. Enterococci
survive more than fecal coliforms under environmental conditions and are better
microbiological water quality indicator. This implicates the possibility of human
health risk since pathogens may be present. Fecal coliform, enterococci, Biochemical
Oxygen Demand, (BOD5), dissolved oxygen, salinity, temperature, pH and caffeine
analysis, were performed monthly to correlate with pollution sources during one year. A
2 x 6 Factorial Sampling Design was used as a guide for data collection. Descriptive
statistic was used to present the data and MiniTab statistical software to analyze it.
Correlation was used to evaluate caffeine concentration relationship with microbiological
water quality compliance (r=1 and p<0.05). Relationships between the parameters and
enterococci suggested a strongly correlation at the representative beaches (r=0.975;
p=0.000). Results also indicate that enterococci are better water quality indicator for
A-41
tropical water (r=0.898; p=0.000).Caffeine presence established wastewater-septic tanks
and storm water discharge representatives as the more affected by anthropogenic
influence. The presence of caffeine on samples in compliance to standards suggests the
location of treated water discharges. Correlation analysis at all the representative
beaches indicate that a change in normal pH is strongly correlated with the presence of
caffeine in water samples (r=998; p=0.000). This dissertation research corroborates the
use of caffeine as an indicator of anthropogenic pollution source of beach tropical waters
samples in Puerto Rico. It uses, as water quality parameter, will be an innovative and
cost effective analysis to evaluate anthropogenic pollution sources and preserve aquatic
environments. These results are consistent with caffeine detected in tropical beaches
with urban influence on a study performed in Hawaii. This is the first study performed in
Puerto Rico, In the Tropical Atlantic Zone and the second in tropical waters.

Contents of Volume 1 (2014).

Transcription

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