Offensive Tastes and Odors Occurring after Chlorine Addition in Water Treatment Processes

Abstract

To identify and eliminate the causes of tastes and odors in drinking water,we have developed a new robot-assisted methodology for absolute threshold flavor determination called “up and down”. A study undertaken at an important biological treatment plant in the suburb of Paris (France) over a period of one year, allowed us to compare results from physico-chemical analyses with those of up and down threshold (UDT) values.This work also demonstrated the very important influence of chlorination on water quality.Furthermore, a number of physico-chemical parameters like POX-TOX and THM were shown to be unsuitable for the prediction of UDT values, but chromatographic finger printing after CLSA extraction and ECD detection showed a possible relationship with UDT.In addition, processes involving dechlorination, stripping and ozonation have been developed to remove chlorine-like odors from treated water supplies.