Environmental impact of triclosan and galaxolide following li ti f t t bi

‫השפעה סביבתית של טריקלוזן וגלקסוליד בקרקעות חקלאיות מטופלות בבוצת‬
.‫פירוק ופוטנציאל להגברת עמידות לאנטיביוטיקה‬, ‫הערכת ספיחה‬:‫שפכים‬
Environmental impact of triclosan and galaxolide following
application
li ti off wastewater
t
t biosolids
bi
lid to
t agricultural
i lt
l soils:
il assessmentt
of sorption, degradation and potential antibiotic resistance propagation
Alla Usyskin, Nadezhda Bukhanovsky, Eddie Cytryn, Mikhail Borisover Institute of Soil, Water and Environmental Sciences, The Volcani Center, ARO
1
Introduction
Experimental part
Results
Conclusions
Pharmaceuticals and Personal
Pharmaceuticals and Personal Care Products (PPCPs)
Therapeutic Th
ti
drugs
Vitamins
Cosmetics
Interest in PPCPs
presence of PPCPs/residues in
and soil environments
water and soil
PPCPs are bioactive
2
EEndocrine d i
disrupting
Promote antibiotic
Promote
antibiotic‐
resistant microorganisms
Introduction
Experimental part
Results
Conclusions
I. Water treatment in wastewater treatment plants → Produces sewage sludge byproduct → Land application of biosolids
sewage sludge sewage sludge byproduct → Land application of biosolids
Valuable source of organic matter The PPCPs accumulated in bi lid and reach agriculture d
h
i lt
biosolids
fields
II. Environmental fate of PPCPs = function of PPCP–soil interactions III. A need to examine sorption of PPCPs on biosolid
III. A need to examine sorption of PPCPs on
biosolid‐amended
amended soils
soils
3
Selected PPCPs
Galaxolide
Triclosan ‫טריקלוזן‬
‫חומר המדכא פעילות‬
‫בקטריאלית ופטרייתית‬
5-chloro-2-(2,4dichlorophenoxy)phenol
79
7.9
4.76
9200
10
4
Galaxolide ‫גלקסוליד‬
‫( סינטטיים‬Musk) ‫חומר ריח‬
*‫תכונות‬
PPCP ‫סוג‬
1,3,4,6,7,8-Hexahydro46678 8
4,6,6,7,8,8hexamethylcyclopenta [g]-2benzopyran
5.9
38600
-
‫סיווג כימי ומבנה‬
pKa
log Kow
(L/kg)Koc **
(mg/L) ‫מסיסות מימית‬
Introduction
Experimental part
Results
Conclusions
Why were triclosan and galaxolide
selected?
l t d?
‰Stable against wastewater treatment
‰Stable against wastewater treatment, ‰Discovered in multiple water samples in WWTPs in Israel ‰Triclosan was found in potatoes and grapes irrigated with TWW
‰ l
f
d
d
d
h
‰ Due to their hydrophobicity, known to accumulate in sewage sludge
Multiple observations of biological effects such as genotoxicity, citotoxicity
M
lti l b
ti
f bi l i l ff t
h
t i it it t i it and d
phytotoxicity
5
Triclosan: a special story
‰Triclosan: a development of antibiotic‐resistant bacteria
‰The products of photodegradation of triclosan may include dioxins and dichlorophenols
Environmental Science and Technology, 2014. Human Fetal Exposure to Triclosan and Triclocarban
H
F t lE
t Ti l
dT i l
b in an Urban Population from Brooklyn, New York,
i
Ub P
l ti f
B kl N Y k
Transformation Products and Human Metabolites of Triclocarban and Triclosan in Sewage Sludge Across the United States
The Impacts of Triclosan on Anaerobic Community Structures, Function, and Antimicrobial Resistance
On the Need and Speed of Regulating Triclosan and Triclocarban in the United States
‰The Swan Song for Triclosan?
‰The Swan Song for Triclosan?
‰FDA and EPA Working in Tandem on Triclosan
6
“General Objective of the research was to characterize the interactions and degradation in soils after sludge application of two representative PPCPs, namely triclosan l d
li ti
ft
t ti PPCP
l ti l
and galaxolide widely disseminated in Israeli wastewater
and galaxolide, widely disseminated in Israeli wastewater treatment facilities”
Better understanding of sorption mechanisms of organic compounds by soils and sediments
d di
t
7
Soils studied: selected properties
Soil type/the sampling location
8
Property
Revadim
Nahal Oz
Duna sand
upper
pp layer
y
mixed
-
Sampling
p g depth
p ((cm))
42
29
5
clay, % w/w
21
20
1
silt, % w/w
37
51
94
sand, % w/w
0.60±0.01
0.39±0.02
0.03±0.01
Organic Carbon (OC)
content,
t t %
Sewage sludge-originating organic amendments
9
Type
[TOC%]
w/w
[TN%]
w/w
Source
Anaerobically digested sludge (Class B)
sludge (Class B)
32±2
5.0±0.3
WWTP Herzliya
y
Secondary aerated sludge (Class A)
37.0±0.2
6.20±0.01
WWTP Shafdan
Sludge compost from mixed organic sources
19.0±0.1
1.9±0.1
Sewage sludge compost
(Dlila, Nahshon)
Introduction
Experimental part
Results
Soils and Biosolids
Soils and Biosolids
Anaerobically Secondary digested sludge aerated sludge (Class B)
(Class B)
(Class A)
(Class A)
10
Sludge compost from mixed organic sources
Conclusions
Incubation for 6 months Incubation
for 6 months
at 30 0C,
ratio equivalent to 80% moisture of f.c.
80% moisture of f.c.
1.5 Mg of N ha‐11
Introduction
Experimental part
Results
Conclusions
S
Sorption experiments ‐
i
i
general methodology
l
h d l
0C in the The kinetics of aqueous sorption was examined at 25 q
p
presents of sodium azide and calcium chloride
Generating equilibrium soil sorption isotherms consisting of 7‐9 different solute concentrations at natural pHs (7.4‐8.2) sand‐based sorbents at
acidic pHs
Fitting the isotherms the Freundlich, Langmuir and linear h
h
h
dli h
dl
sorption models
11
Sorption experiments:
1. 2 compounds X 3 soils X (3 organic amendments +2 control soils)=30 sorbate/sorbent systems )
/
y
at natural pH
2. Triclosan sorption on biosolids
2. Triclosan sorption
on biosolids– no need for galaxolide
no need for galaxolide
3. Triclosan sorption on soil‐amendment mixtures at variable pH (no need for galaxolide)
variable pH (no need for galaxolide)
For each system, both the sorption kinetics and sorption isotherms were determined
4. Triclosan binding with dissolved organic matter (DOM) originating from biosolids – more than half year of work –unlucky with the data
13
Experimental part
Introduction
Results
Conclusions
Triclosan
n sorbed co
oncentration
n, mg/kg
Triclosan sorption on biosolids
Triclosan sorption on biosolids
HSS
H
SSC
C
SSS
S
60000
(OC 29%)
50000
40000
(OC 32%)
30000
(OC 18%)
20000
10000
↑OC ↑Sorption ?
p
0
1
2
3
4
5
6
7
Triclosan eqiulibrium solution concentration, mg/L
pH 6.7‐6.9
14
S ‐ Shafdan sewage sludge H ‐ Herzliya sewage sludge C sewage sludge compost C ‐
sewage sludge compost
Experimental part
Introduction
Results
Conclusions
Triclosan
n sorbed
d concenttration, m
mg/kg
Triclosan sorption on soils and soil‐biosolid Triclosan
sorption on soils and soil biosolid
combinations
250
Clay H
Clay
yC
Clay S
Clay Control
Clay Original
200
150
S ‐ Shafdan sewage sludge H ‐ Her
Herzliya sewage sludge H
liya sewage sludge
C ‐ sewage sludge compost 100
50
0
0
1
2
3
4
5
Triclosan equilibrium solution concentration, mg/L
12
Analysis using the Freundlich sorption model
Analysis using the Freundlich sorption model
Sorbed concentration = K f × (Solution Concentration) n
Where Kf
Wh
Kf is related to the strength of sorption; n describes the extent of a non‐
i l t d t th t
th f
ti
d
ib th
t t f
linearity (a factor of the sorption site – energy distribution)
1.2
1 .0
1.0
0 .8
0.8
0.4
0 .0
0.0
17
Loe
ss
H
Loe
ss C
Loe Loess
S
ss c
ont
Loe
rol
ss o
rigi
nal
0.2
Cla
yH
Cla
yC
C
l
a
Cla
y co y S
ntro
Cla
l
y or
igin
al
0 .2
Loe
ss
Loe H
ss C
Loe Loess
s
S
Loe s cont
rol
ss o
rigi
nal
0 .4
0.6
Cla
yH
Cla
yC
Cla Clay S
yc
Cla ontrol
y or
igin
al
0 .6
San
d H
San
dC
San Sand S
d
San contro
l
do
rigi
nal
n (Triclosan)
1 .2
San
d H
San
dC
San Sand S
d co
ntro
San
l
do
rigi
nal
n (Galaxolide)
Sorption of galaxolide and triclosan: the Freundlich model exponent “n” in various soil systems.
The x axis: "H", “C”, “S”, "Control" and "Original" denote the soil incubated with Herzliya sewage
sludge the sewage sludge compost,
sludge,
compost Shafdan sewage sludge
sludge, as is (without amendments) and the soils
prior the incubation, respectively.
Experimental part
Introduction
Results
Conclusions
Freundlich model exponent (n) plotted against SOC Freundlich
model exponent (n) plotted against SOC
content pH 7.8‐7.9
triclosan
Incubated clay soils + biosolids
Incubated loess soils + biosolids
Incubated sand soils + biosolids
1.20
Original and control clay soils
1.05
R2=0.67
=0 67
n
0.90
Original and control loess soils
Original and control sand soils
0.75
0.60
R2=0.67
0.45
0.0
0.2
0.4
0.6
SOC %
%(w/w)
(w/w)
18
The triclosan‐soil interactions:
0.8
((1)) sandy soil → y
‐ the sorption isotherms less
deviating from the linear
relation (n≈1)
(2) clay rich soils →
‐ isotherms become more non linear (n<1)
non‐linear (n<1)
1.0
(↓ n ↑ SOC) ↑ Clay content ↑triclosan‐sorption sites affinities Experimental part
Introduction
Results
Conclusions
Freundlich constant (K
Freundlich
constant (Kf) vs. soil organic carbon (SOC) ) vs soil organic carbon (SOC)
content
pH 7.8‐7.9
n
Kf ((mg/k
kg)(L/mg) )
150
triclosan
Clay + biosolids
Loess + biosolids
Sand + biosolids
120
Sand
90
60
R2=0.96
=0 96
The triclosan‐soil interactions :
30
0
0.0
Clay + Loess
0.2
0.4
0.6
0.8
SOC %(w/w)
19
one dot represents one isotherm
one dot represents one isotherm
5 dots per each soil type
R2=0.82
SOC content controls SOM SOM
‐ flexible/rigid
the sorption interactions TN content
with the soils
1.0
(1) sandy soil → ‐ flexible and relatively
hydrophobic
y p
OM
(2) clay rich soils →
‐ relatively rigid and less accessible OM
accessible OM Introduction
Experimental part
Results
Conclusions
Freundlich constant (K
Freundlich
constant (Kf) vs. sandy soil organic carbon ) vs sandy soil organic carbon
(SOC) content at various pHs
150
120
Kf
90
Sand ( pH 7.8 ± 0.2)
Sand ( pH 2.5 ± 0.1)
S d ( pH
Sand
H3
3.5
5±0
0.1)
1)
Sandy soil
R2=0.78
99% molecules
60
50% anions
30
R2=0.96
0
0.0
0.1
0.2
SOC %(w/w)
0.3
0.4
triclosan
triclosan anions and molecules demonstrate the comparable affinities in sorption by (sandy) SOM
21
Introduction
Experimental part
Results
Conclusions
SOM is the major soil component
affecting the sorption interactions of both compounds with the soils
22
Selected Conclusions (without details on sorption mechanisms)
1. Organic amendments increase the soil organic matter (SOM) content and soil sorption of chemicals
il
ti
f h i l
2. The strength of soil sorption is linearly related to the SOM content in soils thus producing two groups: (a) clay‐rich soils including clay and loess and (b) sand; sandy sorbents are more effective in sorption of organic compounds than clay‐containing soils, for a given SOM content.
3. SOM‐enhanced soil – organic compound interactions will counteract the rise in the PPCP concentrations in water (e.g., soil solution or groundwater) induced by the PPCP presence in sewage sludge‐based biosolids. This effect will be less expressed in clay‐rich soils with a minimal amount of organic amednments; this counter‐effect will be maximal in sandy soils. 23
PPCPs capability to PPCP
bilit t
be released should be suppressed
suppressed due to
24
increased PPCP‐soil (SOM) interactions
= a × [SOC ] + b
C
SOC is the soil organic carbon content, in % (w/w); "0" refers to the original soil
Kd = S
r=
mb
ms
is the rate of a biosolid application (in w/w);
mb is the mass of a biosolid containing a PPCP compound at its concentration X (mg/kg)
α is the biosolid - originating organic carbon amount added to a ms (a mass of soil), in % to mb
The maximal solution concentration of a PPCP is as follows :
C=
25
r× X
a × {[SOC ]0 + r × α }+ b
The maximal solution concentration of a PPCP is as follows :
r× X
C=
a × {[SOC ]0 + r × α }+ b
Kd = S
C
= a × [SOC ] + b
Significant coefficient “a”, non‐negative “b” (as in the case of sandy soils in contrast to loess and clay)
High extent of a sludge‐born carbon addition 26
Clay − enriched
soils : a = 170 (L/kg/100)
b = − 50 L/kg
[SOC ]0
= 0 .5 %
The m
maximal so
olution cconcentraation norm
malized b
by itts concen
ntration in
n a biosoliid
α = 30 %
0.0002
0 00018
0.00018
0.00016
0.00014
0.00012
0.0001
0.00008
0.00006
0.00004
0.00002
Clay‐enriched soils
Sandy soils
y
0
0
0.02
0.04
0.06
r: the biosolid to soil application rate
Sandy
b = 0
[SOC
soils
]0
α = 100
27
= 0
: a = 220
(L/kg/100)
Presentations and Publications:
1. Usyskin, A., Bukhanovsky, N., Borisover, M. (2013).
Interactions of antibacterial triclosan with soils and sewage organic wastes: the implication for
sorption by sludge-amended soils.
Dahlia Greidinger International Symposium – Advanced methods for investigating nutrient
dynamics, Haifa, Technion, March, 4-7, pp. 116-117.
2. Usyskin,
y
A., Bukhanovsky,
y N., Borisover, M. ((2014).
)
Soils as interfaces against pollution by PPCPs: the effect of sewage sludge disposal. The 8th
International Conference on Interfaces against Pollution (IAP),May 26-28, Leeuwarden, the
Netherlands, p. 121.
3. Two manuscripts are in preparation for submission to the Journals.
28