The document discusses the use of passive sampling devices, specifically the Chemcatcher®, to monitor pollutants in water systems. It notes that passive samplers can provide time-weighted average concentrations over time rather than just snapshots. The Chemcatcher® is introduced as a three-part passive sampler that uses receiving phases like disks to sequester pollutants. Examples of using the Chemcatcher® to detect spikes in pollutants are provided from the UK and India. Future work is proposed to further evaluate the Chemcatcher®'s potential for monitoring and identifying pollution sources in India.

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. 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. 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. 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. 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. Variation in pollution over time
Are TWA values better
for environmental
decision making
processes?

7. Types of passive sampling devices for water monitoring
End slides
5. Purple
DGT
Chemcatcher
MESCO
POCIS
LDPE sheet SPMD

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. 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. 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. 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. 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. 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. Chemcatcher® deployment

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. 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. Metaldehyde Chemcatcher®

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. 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. 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. 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. 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. 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. 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. 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)
• http://chemcatcher.ie/

26. http://www.port.ac.uk/research/chemcatcher/
chemcatcher@port.ac.ukchemcatcher @chemcatcher

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. Chemcatcher® now adopted by research groups and
end-users worldwide as a water quality monitoring tool

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. 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