Evaluation of approaches for consumers to eliminate chlorine off-flavors from drinking water at point-of-use

Chlorine off-flavors of tap water have caused dissatisfaction and distrust from some consumers, placing pressure on operators concerning water disinfection. Evaluating practical approaches for eliminating chlorinous off-flavors by consumers at point-of-use while avoiding production of toxic byproducts is a practical concern. Three recognized dechlorination methods: ultraviolet (UV) irradiation, ascorbic acid (AA) and hydrogen peroxide (HP), were evaluated for chlorinated and chloraminated waters. AA is the most efficient for removing free chlorine and chloramine from water samples. Three new chlorine-containing compounds were detected and identified from the reaction between AA and chlorine. High doses of UV irradiation at 254 nm virtually eliminated chlorine. HP could effectively remove free chlorine but was not effective for chloramine elimination. AA shows promise as a practical household dechlorination agent. However, to assure consumers about drinking water safety, further investigation is needed to evaluate any potential toxicity concerns for reaction products in treated water.