Interactions between river bed morphology, water chemistry and microbial diversity and its impact on pollutant biodegradation

Work at Warwick has demonstrated that river sediment bed-form, such as particle courseness and ripple height, has a major influence on the behaviour of tracers, but the implications for the fate of chemical pollutants remain to be elucidated. Furthermore, in many developing countries, untreated waste water is routinely discharged directly into surface water, and is associated with high levels of suspended solids and biochemical oxygen demand. However the implications of direct discharge conditions for the biodegradation of chemical pollutants is not known. The student will work with microbiologists, civil engineers and environmental modellers to elucidate the effect of bed-form characteristics on the diversity and pollutant degrading potential of microbial communities inhabiting biofilms at the sediment surface, and the way in which direct discharge scenarios affect interactions between bed-form, microbial community composition and pollutant biodegradation rates. The following hypotheses will be tested: 1. Chemical pollutant distribution patterns within river sediment are determined by bed-form 2. Bed-form controls microbial community structure and diversity 3. Bed-form affects the development of catabolic communities and biodegradation rates 4. Direct discharge conditions affect establishment of river-bed microbial communities and biodegradation processes Following the experimental phase of the work the student will spend six months at Unilever to develop approaches to incorporate the results into general exposure modelling frameworks for developed and developing countries. The studentship provides inter-disciplinary training in microbiology, molecular biology, environmental hydraulics and modelling. The industrial partner will provide funding to enable establishment of micro-flume experimental systems and the use of cutting edge techniques, including high throughput sequencing to assess microbial diversity. Furthermore funds will be made available for the student to attend regular national and international conferences and to spend 6 months at Unilever for training in exposure modelling and environmental risk assessment.