Chlorine and Biomonitoring

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.