About The Project

This project provides a unique opportunity to study interactions between chlorine concentration and drinking water biofilms in an operational system.

Aim: To determine the impact of chlorine reduction on water quality and biofilms throughout an operational Water Treatment Works (WTW). Assessing, at each chlorine concentration the: (i) spatial variation in biofilm composition throughout the WTW; (ii) response of established biofilms to changing chlorine concentrations; (iii) biofilm growth rates in Final Waters.

Biofilms, consisting of microbial communities and extracellular polymeric substances, form on internal surfaces of drinking water infrastructure, affecting water quality and infrastructure performance. Managing microbial growth is crucial for safeguarding water quality and infrastructure integrity. Chlorine is commonly used to control planktonic (free-living, in the bulk water) microbial contamination or regrowth, but research indicates bacteria in biofilms are more resistant to biocides. Research using the full-scale pipe loop at the University of Sheffield suggests higher chlorine concentrations select for biofilms with greater discolouration response and distinct microbiomes, yet the impact of chlorine concentration on biofilm growth, composition, structure, and mobilisation in operational systems remains unclear.

How?

A longitudinal study, installing Biofilm Monitoring Devices (BMDs; Pick et al. 2021) at locations throughout an operational WTW during a chlorine reduction process, to enable characterisation of the biofilm microbiome as well as water quality assessment.

Key research questions:

·   How do established biofilms respond to changing chlorine concentrations?

·   How does the biofilm microbiome vary at different stages of the treatment process?

·   How does chlorine concentration impact biofilm growth rate?

Studying and understanding the system will provide:

·       Insight into the impacts of reduction in chlorine on microbial parameters at the WTW and their potential consequences for water quality

·       Invaluable understanding of disinfection practices and their longer-term impact on biofilms and water quality