Project highlights

  • Characterise the spatial and temporal distribution of per- and polyfluoroalkyl substances (PFAS) and other forever pollutant compounds in exemplar urban estuary (Thames) by Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS). 
  • Establish the effectiveness of nature-based solutions to accumulate and degrade forever chemicals. 
  • Identify the transfers from water to suspended particulate to bed sediment to predict current and future pollutant hots spots.  

Overview

Per- and polyfluoroalkyl substances (PFAS) represent a large and complex group of man-made chemicals found in everyday products that are now known to be harmful to humans and ecology. Although their use is regulated internationally under the Stockholm Convention on Persistent Organic Pollutants, water monitoring data suggests they are on the increase as they leach from shredded items in landfill and partly evade degradation during sewage treatment processing; ultimately being discharged into river estuaries. Here our knowledge ends as we lack data tracking compounds associated to the water borne particulates (suspended sediments) and have scant data concerning there incorporation into the river bed. This project therefore aims to examine whether the dilute and disperse strategy employed in the UK and elsewhere can ever co-exist with aspirations of resilient urban rivers that supports diverse array of wildlife, sickness free recreational use and tourism.  

Modern environmental monitoring requires new approaches for understanding highly complex samples.  Ultrahigh resolution mass spectrometry, such as Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS), is a state-of-the-art analytical method which has been playing a leading role in the characterization of the most challenging complex mixtures.  The data sets serve as molecular “profiles” or “fingerprints” for samples, where the data can be visualized and compared.  Collaboration with the Department of Statistics has also resulted in the production of in-house software, used in conjunction with commercial data analysis software.   

In this work we use the River Thames, specifically the reaches down-stream of central London (Bow Creek to Gravesend), to test ideas concerning forever chemical pollution transfer and sediment accumulation, investigating the environmental samples at ultrahigh resolution through the usage of FTICR MS. The study area is currently undergoing significant change and redevelopment (e.g. https://barkingriverside.london/) and yet has a long history of waste management hosting both the Southern and Northern sewer outfalls and also Rainham landfill which receives waste by road (A13) and river. In addition, we will also evaluate whether natural ecosystems, namely urban salt marshes act as stores or sinks or modifiers of forever chemicals such as PFAS with an aim.  

A series of images of chemical compounds, a photo of a tidal river, a photo of a machine and bottles containing liquids.

Figure 1: Are salt marshes a naturebased solution to trapping forever chemicals such as PFAS found in the tidal river Thames.  

Host

University of Warwick

Theme

  • Climate and Environmental Sustainability
  • Organisms and Ecosystems

Supervisors

Project investigator

Co-investigators

How to apply

Methodology

Dr. Vane’s team will provide samples of national and international sites of interest, while Dr. Barrow’s team will provide expertise and access to a 12 T FTICR mass spectrometer and a 15 T FTICR mass spectrometer (the only one in the UK).  FTICR mass spectrometry offers the opportunity to disentangle hundreds to tens of thousands of compounds (non-targeted) to yield unexplored array of chemicals to provide insights into chemical sources and ecological hazard.   

The PhD student will join an active group researching key environmental pollutants of concern and relevance to government and the public.  The student will develop a history of forever chemicals in locations at the nexus between urban tributary run-off, major infrastructure, and macrotidal estuary using sediment cores from river mudflats and saltmarshes (Figure 1).  Furthermore, the student will couple the chemical records with contemporary surveys of suspended sediments and waters to evaluate interactions and transfers.  

Training and skills

DRs will be awarded CENTA Training Credits (CTCs) for participation in CENTA-provided and ‘free choice’ external training. One CTC can be earned per 3 hours training, and DRs must accrue 100 CTCs across the three and a half years of their PhD.  

The student will gain training and expertise in the field of analytical environmental chemistry.  At the University of Warwick, the student will gain expertise from one of the world’s leading FTICR laboratories, operating the highest field FTICR mass spectrometer in the country.  The student will receive training in the collection of environmental samples waters, suspended and bed sediments, as well a salt marsh cores. They will develop skills in contaminant source identification and contaminant chronology. These skills are germane to careers in conservation and environmental science. Further skills will be developed in archive analysis, computer modelling, GIS, and integrated datasets.  

Partners and collaboration

Dr. Barrow has approximately 23 years of experience of working with FTICR mass spectrometry, with a focus on complex mixtures, particularly with respect to petroleum-related samples, environmental samples, fuels, bio-oils/biofuels, archaeological samples, as well as data processing, analysis, and visualization approachesHe has a track record of collaborating with industry and with environmental organizationsDr. Vane has approximately 25 years of experience in the field of organic geochemistry and has been working with the British Geological Survey since 2001 and has established collaborative relationships with the Port of London Authority and with the Port of Milford Haven. 

Further details

For further information, please contact Dr. Vane or Dr. Barrow directly, and see the research group web sites: 

To apply to this project: 

  • You must include a CV with the names of at least two referees (preferably three) who can comment on your academic abilities.  

Applications must be submitted by 23:59 GMT on Wednesday 8th January 2025.  

Possible timeline

Year 1

Co-design sediment and water collection surveys, undertake sediment grab and salt marsh coring, gather pre-existing data on PFAS in waters, sediments in estuaries. Undertake sediment preparation and solvent extractions for analyses.  

Year 2

Characterise PFAS in artificially spiked sediments and urban Thames surface sediments using FTICR MS. Establish anthropogenic forever chemical time-line. Measure PFAS in salt marsh cores and use this information to ascertain whether different zones within urban salt marshes act as permanent chemical stores. 

Year 3

Integrate data from different environmental sites and matrices (water, suspended sediment, bed sediment, marsh core) to understand most frequent and most abundant compound groups and use this to identify.  

Further reading

Downham, R.P., Gannon, B., Lozano, D.C.P., Jones, H.E., Vane, C.H. and Barrow, M.P. 2024.  Tracking the history of polycyclic aromatic compounds in London through a River Thames sediment core and ultrahigh resolution mass spectrometry. Journal of Hazardous Materials, 473, 134605. https://doi.org/10.1016/j.jhazmat.2024.134605
 

Downham, R.P., Vane, C.H., Gannon, B., Olaka, L.D., Barrow, M.P. 2024. Sewage and organic pollution compounds in Nairobi River urban sediments by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Journal of American Mass Spectrometry, (in press). https://doi.org/10.1021/jasms.4c00229
 

Trusler, M.M., Moss-Hayes, V.L., Cook, S., Lomax, B.H. and Vane, C.H., 2024. Microplastics pollution in sediments of the Thames and Medway estuaries, UK: Organic matter associations and predominance of polyethylene. Marine Pollution Bulletin, 208, 116971. https://doi.org/10.1016/j.marpolbul.2024.116971
 

Palacio Lozano, D.C., Thomas, M.J., Jones, H.E. & Barrow, M.P. 2020. Petroleomics: Tools, Challenges, and Developments Annual Review of Analytical Chemistry, 13, 405.
https://doi.org/10.1146/annurev-anchem-091619-091824
 

Thomas, M.J., Collinge, E., Witt, M., Palacio Lozano, D.C., Vane, C.H., Moss-Hayes, V. & Barrow, M.P. 2019. Petroleomic depth profiling of Staten Island salt marsh soil: 2ω detection FTICR MS offers a new solution for the analysis of environmental contaminants. Science of the Total Environment, 662, 852.
https://doi.org/10.1016/j.scitotenv.2019.01.228