Evaluation of a New Disinfection Approach: Efficacy of Chlorine and Bromine Halogenated Contact Disinfection for Reduction of Viruses and Microcystin Toxin

Contaminated drinking water is responsible for causing, diarrheal diseases that kill millions of people a year. Additionally, toxin-producing blue-green algae associated with diarrhea and neurologic effects Continues to he ail issue for many drinking water Supplies. Disinfection has been used to reduce these risks. A novel gravity-fed household drinking water system with canisters containing N-halamine bromine or chlorine media was challenged with MS2 bacteriophape and microcystin. Chlorine and bromine systems were effective against this virus, with an mean +/- SE reduction of 2.98 +/- 0.26 log(10) and 5.02 +/- 0.19 log(10), respectively. Microcystin toxin was reduced by 27.5% and 88.5% to overall mean SE concentrations of 1,600 +/- 98 ng/L and 259 +/- 50 ng/L for the chlorine and bromine canisters, respectively. Only the bromine units consistently produced microcystin effluent < 1,000 ng/L (the World Health Organization recommended level) when challenged with 2,500 ng/L and consistently surpassed the U.S. Environmental Protection Agency Virus reduction goal of 99.99%.