Following their use by society, synthetic chemicals used as agrochemicals, pharmaceuticals and veterinary medicines can be released into the environment, where there is the potential for them to exert adverse effects on ecosystems and human health. In order to assess these risks we need to understand the factors which control chemical fate and persistence in the environment.

Before chemicals can be approved for use, they must undergo regulatory testing to determine the rate and extent of degradation, and their potential to persist in the environment. However, such studies are conducted under standardised laboratory conditions, are limited in scale, and fail to replicate the dynamic nature and complexity of real world environments.

For most chemicals, biodegradation by microbial communities is the key process which determines environmental persistence. Biodegradation rates are determined by complex interplay between environmental parameters and the abundance and functional characteristics of microbial communities, which are highly diverse, and variable in space and time.


This project will investigate how environmental factors interact to influence chemical biodegradation processes in aquatic systems.  Most degradation takes place in the sediment rather than the overlying water, and the project will particularly investigate factors which influence water-sediment exchange of chemicals, including the nature of the sediment bed and water flow rate. These processes may be influenced by  cyanobacteria, which can grow on the sediment and affect exchange processes, and may also contribute to degradation. Microbial diversity plays a key role in determining biodegradation potential. You will use metagenomic and metatranscriptomic approaches to unravel the nature of microbial communities contributing to chemical degradation, and the specific degradation pathways involved. Recently we have found that microbial diversity within laboratory biodegradation test studies is affected by system scale, and that this may influence biodegradation rate. Metagenomic approaches will be used to investigate realtionships between scale, microbial diversity and microbial function. Experiments will be conducted with a range of synthetic chemicals, which could include pesticides, pharmaceuticals and daily use chemicals.

Training and Skills

CENTA students are required to complete 45 days training throughout their PhD including a 10 day placement. In the first year, students will be trained as a single cohort on environmental science, research methods and core skills. Throughout the PhD, training will progress from core skills sets to master classes specific to CENTA research themes. 


Year 1:  Studies in controlled environemnt microflumes to investigate effects of sediment characteristics, bedform and light on water-sediment chemical exchange and biodegradation

Year 2:  Analysis of microbial community dynamics in microflume experiments, using ‘omic approaches

Year 3: Investigate the effect of scale on microbial diversity and function

Partners and collaboration (including CASE)

Potential for CASE funding from Syngenta or Unilever. 

Further Details

Professor Gary Bending

School of Life sciences

University of Warwick



Email: gary.bending@warwick.ac.uk

Direct Line: 024 76575057