Impact of Particulate Matter on the Inactivation by Chlorine and Monochloramine ofEscherichia coli O157:H7 and MS 2 Bacteriophages

摘要

Treating drinking water at the treatment plant effluent to meet regulatory requirementsrndoes not necessarily ensure high quality water at the consumer's tap. During distribution, waterrnquality degrades, which may lead to increased bacterial counts with possible coliformrnoccurrences and depletion of disinfectant residual. The maintenance of a disinfectant residual inrndistribution systems has traditionally been used to protect microbial water quality. It is necessaryrnto understand the reasons for the presence and survival of microorganisms in distributionrnsystems despite the continuing presence of disinfectant residuals. The overall aim of this benchscalernstudy was to quantify differences in the inactivation kinetics of E. coli O157:H7 and MS 2rnphages in the presence of particulate matter, and compare those kinetics to the kinetics obtainedrnin parallel experiments in pure water.rnThe types of particles that were used in the experiments included iron pipe corrosionrndebris (at 50 mg/L), soil contamination to simulate a pipe break (at 50 and 200 mg/L), andrnmunicipal wastewater solids to simulate cross-contamination (added to reach a water turbidity ofrn2.0 NTU). A soil sample was collected adjacent to a drinking water pipe in Toronto. Corrosion