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Fones G - UEI Day 1 - Kochi Jan18


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Fones G - UEI Day 1 - Kochi Jan18

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Fones G - UEI Day 1 - Kochi Jan18

  1. 1. The use of passive sampling devices to monitor polar anthropogenic pollutants and application to river catchments in India Professor Gary Fones – Professor of Environmental Aquatic Chemistry
  2. 2. Overview • Monitoring chemical pollutants • Passive sampling devices (PSDs) • Chemcatcher® passive sampler • Examples of use of Chemcatcher® in UK • Use of Chemcatcher ® in India • Future use of sampler in India? • Summary and way forwards
  3. 3. Monitoring chemical pollutants • Currently the most widely used method for measuring concentrations of chemical pollutants in regulatory monitoring programmes is spot (bottle/grab) sampling followed by chemical analysis in remote laboratory. • Automated samplers (ISCOs) This approach has a number of disadvantages: • Cost (manpower/transport). • Provides only a ‘snapshot’ of the pollution situation at the instant of sampling. • May not be representative of conditions where concentrations of pollutants fluctuate or are not homogeneous. • Issues of achieving detection limits (EQS) when low volume spot samples (1-5 L) are only collected. • Potential to generate misleading information on which management and remediation decisions are based?
  4. 4. Monitoring chemical pollutants  UoP daily data in accordance with EA spot samples data  However large spikes are being missed by monthly spot samples  Mean EA data 12/2015-11/2016 : 0.034 mgP/L  Mean UoP daily data 12/2015-11/2016: 0.067 mgP/L
  5. 5. Passive samplers for monitoring the aquatic environment • Can provide time-weighted-average (TWA) and equilibrium (non-polar organics) concentrations over the deployment time, rather than a snap shot at one moment • Typically measure the freely dissolved (biologically available fraction?) • Are non-mechanical; are easy to deploy and require no maintenance • Can be deployed in a range of environments; at sites that have limited security; are remote with little/no infrastructure • Are not dependent on a power or other energy supply • Used for short (days) or long term (months) monitoring • Can also effectively concentrate pollutants • compared to spot sampling – lower analytical detection limits
  6. 6. Variation in pollution over time Are TWA values better for environmental decision making processes?
  7. 7. Types of passive sampling devices for water monitoring End slides 5. Purple DGT Chemcatcher MESCO POCIS LDPE sheet SPMD
  8. 8. Two main types of passive sampling device for polar and many emerging pollutants Chemcatcher® Polar organic compound integrative sampler (POCIS) - USGS • Both use adsorptive and/or ion-exchange mechanisms to sequester pollutants. • Smaller active sampling area (~ 15-45 cm2) compared to non-polar sampler designs. • Lower uptake rates ~ 10-100 mL/day across wide range of substances. • Use of PRCs deemed not applicable due to non-isotopic exchange. • Generally uptake rates not affected significantly by water temperature and turbulence. Development lags behind that of non-polar polymer-based samplers for regulatory use.
  9. 9. Development of a passive or time integrative sampler for water • In 1996 very little technology available for routine use with water • Develop a simple easy, adaptable, low cost to use device, compatible with existing laboratory analytical procedures • Assisted by EU funding (1997- 2000) led to the development of the called ‘Chemcatcher’ passive sampler – with five other European partners • UoP – Professors Richard Greenwood & Graham Mills • Early on UoP saw potential – investment with patents and trade mark
  10. 10. What is the polar Chemcatcher® device? 3 part PTFE body Polyethersulphone membrane (50 mm diameter) Receiving phase (47 mm) 3M Empore™ disks SDB-XC SDB-RS Anion-exchange Cation-exchange Carbon Phases bound into PTFE matrix – high loading/capacity Or more recently: Horizon Atlantic® disks: polymeric HLB (Hydrophilic/Lipophilic Balanced) - as used in the POCIS or DVB media bound in a glass fibre matrix. Both disks used for extraction chemicals from water in the laboratory. High quality analytical chemistry SPE products, available worldwide. Their use gives highly reproducible, simple passive samplers.
  11. 11. Solving water quality issues caused by polar pollutants using passive samplers • Polar chemicals often have sporadic inputs in water bodies (seasonal use of pesticides). • High water solubility (not bound to particulates), high mobility in water column. • Chemcatcher® can be used ‘forensically’ to pin point sources of pollution in a catchment. • ‘Screening’ mode for the presence or absence of compounds
  12. 12. Chemcatcher® – Semi-quantitative and quantitative assessment • As well as “detective work” can also be used for quantification • Need the uptake rate to determine quantification of target compounds • Requires calibration of the Chemcatcher® under laboratory conditions
  13. 13. Time weighted average concentration Time weighted average (TWA) concentrations (CW in ng L-1) can be derived from a simple equation: where: MS = mass of pollutant on Chemcatcher disk (ng) M0 = mass of pollutant on field blank Chemcatcher disk (ng) RS = sampling rate of pollutant (L day-1) t = Chemcatcher deployment period (days)
  14. 14. Chemcatcher® deployment
  15. 15. Upstream thinking – a river catchment management project Upstream Thinking is South West Water's flagship programme of environmental improvements aimed at improving water quality in river catchments in order to reduce water treatment costs. Chemcatcher® detected spikes of herbicide pollution after rainfall events missed by spot sampling and approach is now being widely used by South West Water Ltd. and others in managing their river catchments. Collaborative project using Chemcatcher® to detect point sources and measure concentrations of widely used and problematic TARGETED herbicides in the Exe catchment. Mecoprop, MCPA, tricolpyr and clopyralid herbicides widely used to control broad-leaved weeds and these compounds are very water soluble – easy to enter river.
  16. 16. Metaldehyde Chemcatcher® • Molluscicide widely used on cereals and oilseed rape • Very stable, high solubility and mobile in the environment • Hard to remove from water even using advanced treatment processes • Has frequently exceeded 0.1 µg L- 1 PCV (prescribed concentration or value) in treated water since monitoring began in mid-2000s. • Study funded by NERC iCASE studentship with South West Water – Additional funding from Thames Water and Affinity Water. PhD Student – Mr Glenn Castle
  17. 17. Metaldehyde Chemcatcher®
  18. 18. In-situ calibration of polar Chemcatcher® - pharmaceuticals & illicit drugs • Interest in monitoring drugs in water • Chemcatcher with Horizon HBL phase and PES membrane • Deployed for 9-days in effluent of waste water treatment plant • Attempt to measure in-situ uptake rate of 60 substances • Compare data to spot sampling using bottle auto- sampler • Use derived uptake data in subsequent field trials • Agreement within a factor of 2 of known water concentration Overall uptake rates ranged: 10 to 100 mL day-1
  19. 19. Chemcatcher® - Pharmaceuticals • IUKWC Researcher Exchange – “The use of passive sampling devices to improve the monitoring of anthropogenic pollutants in river catchments in India” • Dr Priyanka Jamwal (Ashoka Trust for Research in Ecology and the Environment (ATREE) • Before visit in May 2017 – Deployments undertaken in March-April 2017 • Polar Horizon Atlantic Chemcatcher® deployed at the outlet of 4 STPs in the Bangalore region (13-14 days) • Jakkur Lake (centralized – 115 L s-1); Vrishbhavathi Valley (centralized – 2100 L s-1); Royal Manor (decentralized – 0.9 L s-1); Brigade Gardenia (decentralized – 3 L s-1) • Analysis undertaken at NRW, UK. Screening of HLB-L disks using a Bruker Impact II™ - Ultra-High Resolution Qq-Time-of-Flight mass spectrometer with > 50,000 Full- Sensitivity Resolution (FSR).
  20. 20. Chemcatcher®– Screening of Pharmaceuticals • > 90 compounds identified in screen • ToxScreener (Bruker) database • 68 identified (100% confidence) • ~ 22 identified (95-99% confidence) • Antibiotics (Ofloxacin and Erythromycin) • Antidepressants (Imipramine and Delorazepam) • Antiretroviral drugs (HIV/AIDS) (Ritonavir and Lopinivar) - Protease inhibitors (Kaletra) • For quantitative values – need to undertake series of calibrations and laboratory quantification (uptake/retrieval)
  21. 21. Chemcatcher®– Quantification of Pharmaceuticals Pharmaceutical Jakkur Lake Vrishbhavathi Valley Royal Manor Brigade Gardenia TRAMADOL 564 20 0.7 11 FEXOFENADINE 10 14 60 43 ATENOLOL 22 97 40 14 CARBAMAZEPINE 43 25 35 6 DICLOFENAC 58 41 64 71 NAPROXEN 5 23 25 18 VENLAFAXINE 81 NA NA 0.4 Semi-quantitative concentrations obtained using uptake rates from Petrie et al. 2016 paper. Values are similar to STP plant in West Country of the UK. Concentrations are in ng L-1 Paracetamol and Diazepam
  22. 22. Potential future work in India Need to undertake some pilot trials: 1. Calibration trials of passive samplers to assess their utility in the Indian sub-continent (high temperatures, concentrations, organics, complex mixtures, biofouling etc. 2. Comparison of inlet (grab samples) versus outlet (PSDs) to see what is being removed – improve treatment work processes 3. Deployment throughout a catchment to ascertain sources, pathways and fate of contaminants. 4. Potential of developing new receiving phases – compound specific e.g. MIPs (Molecularly Imprinted Polymer) 5. Trials with other contaminants for forensic work – e.g. metals and nutrients
  23. 23. Potential future work in India Trials with cheaper and obtainable analytical costs. Example – metal discharges in Bangalore Missed by infrequent spot sampling, but picked up by high temporal sampling. Night time industrial discharges
  24. 24. Chemcatcher® - Summary • Passive samplers can effectively concentrate pollutants compared to spot sampling – lower analytical detection limits (E[w]QSs) • Passive samplers can provide time-weighted-average (TWA) and equilibrium concentrations over the deployment time, rather than a snap shot at one moment • “Screening” mode for the presence or absence of compounds • Usually used in “detective work” to pinpoint sources of pollution in a river catchment • Samplers can subsequently be calibrated for these key pollutants for a quantitative assessment of pollutant loads • Data generated from PSDs can be used to develop catchment management solutions. • Good evidence that passive sampling and spot sampling are compliant for polar compounds. • Passive samplers provide better overall representation of water quality over time.
  25. 25. Chemcatcher® - Acknowledgements • University of Portsmouth • Professor Graham Mills • Professor Richard Greenwood • Dr Adil Bakir • Mr Glenn Castle • Mr Adam Taylor • Dr Anthony Gravell – Natural Resources Wales • NERC • India-UK Water Centre • South West Water • Thames Water • Affinity Water • Southern Water • New commercial agreement with T.E. Labs (Eire) •
  26. 26. @chemcatcher
  27. 27. More representative monitoring methods to avoid missing pollution events? • Use of passive samplers? • Long history (1970s) of their use in monitoring pollutants in air • Range of devices available commercially • Some low-cost, easy to use and detect a wide range of chemicals • Estimate average exposure to solvent vapours over a 8 h work shift • Data from samplers is used for regulatory purposes
  28. 28. Chemcatcher® now adopted by research groups and end-users worldwide as a water quality monitoring tool
  29. 29. Some problems still to be solved – biofouling of the diffusional surfaces of the sampler Fouling limits the deployment time of the passive sampling devices and sensors
  30. 30. Deployment and retrieval of Chemcatcher® Sampling cage (lid removed) Cage lid with three Chemcatchers attached Cage after two week deployment Deployment of the Chemcatcher® on site Limited biofouling of PES membrane