HydroCycle-PO : Fish sticks and fertilizer meet - Sea

HydroCycle-PO4: Fish sticks and
fertilizer meet their match
Corey Koch, Michael Dewey, Bruce Rhoades, Nichole Halsey
Rio Grande in Albuquerque
Overview
• Instrument Overview
• Tank tests for bubbles and
sediment
• Real-time QC flags
• Great Bay, NH application
• Instrument agreement in Yaquina
Bay, OR
• Recent results from Maumee ACTEPA Nutrient Challenge
Performance Specifications
•  Soluble reactive ortho-phosphate
• 5-10 um pore size filter
• LOD, IDL: 3*  0.0023 mgP/L (75 nM PO₄)
• Range: 0-0.3 mgP/L (0-10 µM PO4)
• linear to ~1.2mgP/L
• Maximum 4 samples per hour
• 0-35C, 0-200 meters
• On-board memory, but needs a battery
3
Instrument and Chemistry
• On board reagent cartridges (5 mo best-by)
• On-board spike calibration (NIST Traceable
Standard)
• NIST Standard 10-25C
4
Based on:
-Murphy, J.; Riley J.P. Anal. Chim. Acta. (1962)
-US EPA method 365.5
HydroCycle-PO4 Data Collection- Step by Step
• Over 1500 samples
• Deployments more
than three months
1. Ambient sample flush/rinse
4.
2. Baseline (ambient) measurement
5.
3. Mixing: reagents added, pumps sample
to optical cell
6.
Sample reaction: product formation*
Reaction completed, slope inflection point
identified
Flush and rinse with ambient
~ 20 minutes per sample
5
HydroCycle-PO4 improvements over Cycle-PO4
• Real-time Quality Control flags
• Improved filter life and data quality
• High oxygen saturation condition ready
– Productive waters, entrained bubbles, or
outgassing in pumped tank systems.
• Less variability in sensor-sensor data
quality
• 30% more runs and 5 month reagent life
– Low air injection cartridges and Lot #’s
Bring on the Bubbles
• Bubbles can compromise fluidic volumes
and cause catastrophic optical noise.
• HydroCycle-PO4 tested extensively in a
bubble tank with saturated water
– filled with macro and micro bubbles, allowed to
collect under and on filter surface
– Tested in the field at estuarine and riverine sites
• Can continue to make measurements in
presence of micro / macro bubbles in the
sample
– Patent application submitted
Simulated Mud Puddles
• Tank tests with Elliot Silt Loam,
Maumee, Rio Grande, Murkderkill
estuary, and Missouri River
Sediment
• Single filter disc with 7.5 um avg pore size
• Better data quality in fine sediment
• 500 NTU sample resulted in 3 NTU filtrate (10 um filter 250
NTU)
• Uniform caking and larger area lead to longer filter life
– Expected to survive a few short duration (day) high sediment events
• HydroCycle-PO4 can do ~100 runs at NTUs varying from
100-500 NTU.
– 10x longer than Cycle in Elliot Silt Loam
Sensor Specific QC flags
•
•
•
•
Real-time data assigned QC flag, software plot
color-coded
Overall flag composite of the six individual quality
flags:
• out-of-range, optical noise, low signal,
bubbles, mixing errors.
Ability to change thresholds and post-process data
sets
Save analysis reports with data statistics and
embedded links to files for database creation
UNESCO Flag levels,
adopted by IOOS
Software % of data flagged table
Sherson and Van Horn; Jemez River, NM after fire flushes.
Suspect due to out of range, low signal leads to bad data
Great Bay and NERACOOS
• NERACOOS developing in-situ nutrient
observatory (nitrate, phosphate,
ammonium)
• Large jumps in non-point nutrient
loading due to population growth and
increasing urbanization.
• Phosphorus is from tidal, estuarine,
and terrestrial sources,
– requiring high frequency observations
to understand ecosystem impacts
Great Bay Phosphate sourcing
• Early in the deployment FDOM
serves as a tracer of terrigenous
phosphate sourcing
• Later in the deployment phosphate
lags FDOM indicating Ocean
sourcing (comes into phase with
tidal cycle)
Instrument-to-Instrument Agreement
• Several sensors deployed side-by-side
• Evaluate ability to swap/compare
• Demonstrate sensor-sensor data quality
• Changes  0.002 mgP/L coherent
between instruments
• May capture spatial heterogeneity
Maumee River
• Selected for ACT/EPA Nutrient Sensor challenge
– Graded on Accuracy, Precision, Range, longevity, and
cost
– First test Maumee River in Ohio
• Unfortunately, data at or below the detection
limit!
• Sorry there weren’t any fishsticks…
– Algal farming in York River, MS State Aquaculture ponds
• Acknowledgements:
– Justin Reale (CoE), Dave Van Horn (UNM)
– Thomas K. Gregory (UNH), Cassie Durrent Stymiest (NERANOOS)
– ACT nutrient challenge team: Tom Johengen, Heidi Purcell, Dan Schar
and Dave Loewensteiner
– SeaBird team: Jeff Pauk, Jim Pearson, Kate Threlfall, Gabe Ryan, Adam
Dutton (SeaBird)
– Doug Wilson (Caribbean Wind)