Evaluation of Real-Time Water Quality Sensors for the Detection of Intentional Bacterial Spore Contamination of Potable Water

Samendra P Sherchan Charles P Gerba

doi:10.4172/2155-6210.1000141

Abstract

Water utility treatment failure, as well as intentional or accidental water intrusions can introduce biological and/ or chemical contaminants into public drinking water distribution systems. However, recently developed real-time water quality sensors can be implemented to detect such contamination events. The overall objective of this study was to evaluate the potential for real-time monitoring of bacterial spore contamination of potable water using several different water quality sensors including: the HACH Monitoring Platform; the JMAR BioSentry unit; and the S::CAN spectro::lyser technology. For this, Bacillus thuringiensis spores were used as a surrogate for Bacillus anthracis. The minimum threshold response of sensors to the microbial contaminant was determined by injecting B. thuringiensis spores into Deionized (DI), filtered or unfiltered tap water. Out of these three evaluated sensors, the BioSentry sensor was capable of detecting introduced spores and responded to B. thuringiensis spores over a concentration range of 10 2 -10 5 spores/ml. In contrast, The HACH and S::CAN units were not capable of direct detection of spores. However, these two sensors can detect changes in water quality parameters such as turbidity, pH, temperature, total organic carbon and conductivity, due to media that may be associated with spores. Thus, these sensors can be integrated into a contaminant warning system for monitoring intrusion events in water distribution systems.

Highlights

Access to high quality water through sustainable treatment and effective water distribution systems is essential to contemporary life in developed countries
The objective of this study was to evaluate the potential for realtime monitoring of B. thuringiensis spores as a surrogate for B. anthracis using a variety of water quality sensors
The objective of this study was to evaluate the ability of commercial sensors to detect B. thuringiensis bacterial spores in-line and in real-time

Summary

Introduction

Access to high quality water through sustainable treatment and effective water distribution systems is essential to contemporary life in developed countries. To monitor for microbial contaminants most municipal water utilities rely on indicator organism tests (i.e. fecal coliform or E. coli tests) that take up to 24 hours to obtain results, and are incapable of monitoring pathogens need to be detected in real-time. The lack of real-time monitoring of distribution systems potentially exposes the public to pathogenic microorganisms. The use of integrated and intelligent sensors to operate in real-time, with the ability to recognize and diagnose day-to-day and perhaps minute-to-minute water quality disturbances can monitor water quality through the detection of intentional or operational intrusion events, improving water security. When contamination events are recognized in real-time, a rapid response can minimize the impact of these contamination events and limit the potential for adverse effects [2]

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