Project Overview

To Chlorinate or Not to Chlorinate?

Introduction

Safe drinking water is essential for public health, wellbeing, society and the economy. Yet the number and incidence of opportunistic pathogen outbreaks in DWDS is increasing globally, especially in developed countries and where disinfectant residuals are used.

The central provocative hypothesis is that disinfectant residuals promote a resistant biofilm, providing a beneficial habitat for pathogens to colonise and proliferate; these biofilms are sporadically mobilised into the water column, where they can pose a public health risk.

The Challenge

Fundamentally it is still unknown how disinfectant residuals impact DWDS biofilms, particularly the potential for colonisation, sheltering and growth of pathogenic microorganisms, and, consequently, how disinfectants influence the overall public health risk from drinking water.

Research Proposal

This proposal will deliver new knowledge, fundamental understanding and practical guidance regarding disinfection residuals, biofilms and, specifically, the fate of pathogens in DWDS under different disinfection regimes. Key advances and contributions will include:

(i) Understanding and modelling pathogen colonisation, survival and proliferation within DWDS biofilms;

(ii) Quantifying the probability and exposure from biofilm containing pathogens being mobilised into the bulk water;

(iii) Evidencing the impact of disinfection regimes upon DWDS biofilm characteristics and processes;

(iv) Evaluating the efficacy of maintenance, cleaning and disinfectant techniques in controlling biofilm associated pathogens.

Programme of Work

Physical Experiments

Biofilm reactors will enable precise control and replication of a wide range of disinfection regimes. The internationally unique pipe loop facility at the University of Sheffield will be used, as intentional contamination of operational systems is inconceivable.

Advanced Water and Biofilm Analysis

Pathogen behaviour will be resolved by an extensive suite of state-of-the-art approaches.

Biofilm Modelling & Quantitative Microbial Risk Assessment (QMRA)

We will use functionality to describe the emergent biofilm and pathogen behaviour in response to environmental factors, primarily disinfection residual regime.