- This project will improve fundamental understanding of pollutant behaviour in rivers
- Combination of state of the art numerical modelling, environmental sampling and analysis
- Opportunity to engage in an established international collaboration with exciting fieldwork
Urban areas are a major source of water pollution in developing countries where a significant (but often unknown) fraction of urban wastewater is discharged with little or no treatment. Urban wastewater contains a range of synthetic organic compounds (e.g. pharmaceuticals, home and personal care products) which can result in major ecological impacts. Understanding the sources, transport and transformation of pollutants and their impact on receiving ecosystems is crucial for effective water resource management and the reduction of chemical risks to people and the environment.
In this project, we will improve our understanding of pollutant behaviour in rivers under direct (untreated) discharge scenarios and develop a model of waste-water derived pollutant exposure and ecotoxicological effects in surface waters within and beyond urban areas. The model will act as an extended hypothesis which will be calibrated and tested via field investigations in Kerala, India. The impact of organic pollutants from urban waste water on surface water quality will be evaluated using a combination of existing water quality data and new monitoring of concentrations and fluxes of marker compounds intended to be representative of particular uses (e.g. personal care products, laundry product ingredients or pharmaceuticals) and chemical properties (e.g. hydrophobicity, degradability and toxic mode of action).
The in-channel fate of organic pollutants will depend on physico-chemical properties and compound degradability as well as environmental factors like temperature, pH, suspended solids concentration, dissolved organic carbon concentration and the hydraulics of the receiving system. We hypothesise that biodegradation will be more rapid in shallow streams than in deep rivers because the size of the competent microbial biomass in the water column is low compared with that in biofilms attached to the wetted perimeter of the channel. This means that degradation will depend on contact time with the fixed biofilm.
We will build a model to predict rate constants from channel geometry, bed characteristics and associated hydraulics which will be validated by monitoring the dynamics of key marker compounds in river reaches downstream of urban centres which have different hydraulic geometries. Degradation rate constants will be derived by measuring changes in pollutant concentrations with flow time downstream – tracked using a pulse injection of a fluorescent dye which can be detected at downstream stations, allowing sample collection to be staggered by solute travel time. In parallel, we will conduct ecological surveys to assess in-stream ecological quality at different locations in order to assess ecological recovery associated with decreases in pollutant stressor exposure away from urban areas. We will combine the data on spatial and temporal variations in water quality and our observations of spatial patterns of ecological quality to produce an explanatory model of ecotoxicological impact.
Training and Skills
Full training will be given in the planning and execution of river water quality sampling campaigns, dye tracing, ecological surveys and in the analysis of water samples for a range of organic pollutants using LC MS/MS. Water samples will be analysed in state of the art laboratories at Mahatma Gandhi University in Kottayam, Kerala. Specific training will also be given in the statistical analysis of data and in the construction of numerical models of river water quality.
Year 1: Literature review and project planning. Field reconnaissance and preliminary sampling trips to Kerala. Training on sampling and water quality analysis. Training on numerical modelling.
Year 2: River water quality sampling campaigns (including dye traces) and ecological surveys in India. Analysis of samples and interpretation of data. Further training in modelling and initial model development.
Year 3: Follow up sampling and manipulative laboratory experiments to refine model. Model development and validation. Data analysis, paper and thesis writing.
Partners and collaboration (including CASE)
The project will be run in collaboration with Professor C.T. Aravindakumar’s group at Mahatma Gandhi University in Kottayam, Kerala with additional support for travel and subsistence provided via an existing SPARC / UK-India Education and Research Initiative (UKIERI) grant (project code P1461) and with Unilever (UK and India) who will act as a CASE partner. Professor Ian Guymer and Professor Lorraine Maltby from the University of Sheffield will also be involved in the project.
This project has been selected as a CENTA Flagship project. This is based on the projects fulfilment of specific characteristics e.g., NERC CASE support, collaboration with our CENTA high-level end-users, diversity of the supervisory team, career development of the supervisory team, collaboration with one of our Research Centre Partners (BGS, CEH, NCEO, NCAS), or a potential applicant co-development of the project.
For further details about the project please contact Dr Mick Whelan at the University of Leicester (email@example.com).