Sarah Purnell

Sarah Purnell is a Principal Research Fellow within the School of Environment and Technology. She is a member of the Environment and Public Health Research and Enterprise Group (EPHREG) and is the water and wastewater quality and treatment representative for the Centre for Aquatic Environments (CAE).

Sarah undertook an environmental microbiology PhD entitled ‘Bacteriophage of Enterococcus species for microbial source tracking’ at the University of Brighton, which she completed in 2012. She was appointed as Research Officer on the EU Interreg-funded project AquaManche, a cross-border initiative that aimed to deliver practical tools to improve prediction, mitigation and management of river and coastal waters in the France (Channel) - England region. Sarah was appointed as Research Fellow at Brighton on the follow-on Interreg project RiskManche. It was during these projects that Sarah became increasingly interested in applied research, which focuses on identifying and managing water quality contaminants. Sarah has since been the principal investigator on eight research projects in collaboration with the UK water industry and has been a co-investigator on a further four projects applying low-cost tools developed in the UK, globally. These include two Bill and Melinda Gates Foundation-funded projects based in India. In 2018, Sarah’s research on prediction of metaldehyde in water systems was nominated for the Institute of Water Innovation Awards.

My main research interests focus upon the design, development and application of tools that can identify and help manage aquatic environments impacted by a range of existing and emerging contaminants. These contaminants have the potential to negatively impact human health and the ecological and chemical quality of aquatic environments. It is important to me that I pursue research that is practical and can feed directly into catchment management undertaken by water quality managers. As such, a large proportion of my research is in collaboration with water industry partners. My research projects can be divided into three main topic areas:

Bacteriophage application to water quality issues

Bacteriophages have been proposed as appropriate indicators for the presence of pathogenic viruses in water. They have similar structure, morphology, size and survival properties to pathogenic viruses. Interestingly, bacteriophages can also exhibit specificity to bacteria found exclusively in human or non-human animals and have been used to identify faecal inputs into aquatic environments. Therefore, bacteriophages represent useful low-cost tools for studying the presence, transport, and survival of viral pathogens in a range of settings. Examples of my research in this area include the detection of different bacteriophage groups in water and shellfish; development of Enterococcus bacteriophage microbial source tracking (MST) markers; application and survival studies of a range of bacteriophages proposed as MST markers; Bill and Melinda Gates Foundation funded projects based in India applying and developing bacteriophage MST tools; research in collaboration with South East Water using bacteriophages alongside genetic MST markers to identify nutrient inputs; and research in collaboration with Thames Water into the application of bacteriophages as surrogates for pathogenic viruses to assess the ability of a range of wastewater treatment technology to remove viruses.

Quantitative microbial risk assessment

Research in collaboration with South East Water has focussed on quantitative microbial risk assessment (QMRA) approaches to assess the potential human health risk to recreational users of surface waters augmented with treated wastewater.

River catchment scale predictive water quality modelling

Research in collaboration with Southern Water has considered how low-cost catchment modelling approaches (e.g. ArcSWAT) can help to predict where and when water quality issues are most likely to arise.

My teaching is driven by published research and my own recent and ongoing research projects. By integrating research into sessions and encouraging students to read the latest published literature, they have the chance to explore contemporary problems affecting society and discover how these can be addressed. In my modules, there is also a strong element of applied science taught through a range of different practical sessions. In these sessions, students have access to the state-of-the-art research facilities of the Centre for Aquatic Environments (CAE), including specialist water quality laboratories, as well as a large array of field equipment. This is evident in my MSc level module ‘Water Quality Analysis’, where students spend time in the River Ouse catchment (Sussex) getting to grips with a range of water quality sampling methods. This is then followed by sessions in our microbial and geochemical laboratories, where students use research grade equipment to analyse samples collected for a range of important water quality parameters.  

I am interested in supervising postgraduate research students in the field of water and wastewater quality and treatment, with a focus on environmental microbiology, prediction and mapping and risk assessment.