Friday, January 6, 2012

Keeping Our Beaches Safe from Fecal Contamination

Fecal contamination of public beaches caused by sewage overflow is both dangerous for swimmers and costly for state and local economies. Current methods to detect Escherichia coli, a bacterium highly indicative of the presence of fecal matter in water, typically require 24-48 hours to produce a result.

A new, accurate, and economical sensor-based device capable of measuring E. coli levels in water samples in less than 1-8 hours could serve as a valuable early warning tool and is described in an article in Environmental Engineering Science, a peer-reviewed journal published by Mary Ann Liebert, Inc.

The article provides a detailed description of the autonomous, wireless, in-situ (AWISS), battery-powered device, which contains a prototype optical sensor that can measure changes in fluorescence intensity in a water sample. In the presence of E. coli bacteria an enzymatic reaction will cause an increase in fluorescence. The AWISS can detect high concentrations of bacteria in less than 1 hour and lower concentrations in less than 8 hours. Read More