Chemical and microbial decontamination of pool water using activated potassium peroxymonosulfate

Abstract

Potassium peroxymonosulfate activation leads to the formation of highly reactive species, mainly the sulfate radicals. Activated potassium peroxymonosulfate (from now on peroxymonosulfate) was tested against specific pollutants such as ammonium ion, creatinine, chlorinated creatinine products, arginine and Escherichia coli ( E. coli), all constituents or derivatives of human discharges. The objective was to assess whether activated peroxymonosulfate can be a viable treatment reagent in recreational water applications. It was found that organic molecules such as creatinine, chlorinated creatinine products and arginine could be effectively treated with activated peroxymonosulfate. Ammonium ion was oxidized only by chlorine species and only in de-ionized water. Chlorine species were formed from the reaction of sulfate radicals with chloride ions. In pool water, the reaction of sulfate radicals with chloride ions and the subsequent ammonium ion oxidation were scavenged by the presence of bicarbonate ions. The Co/Peroxymonosulfate system was also shown to be an effective disinfection reagent, since 99.99% (4-log) kill of E. coli was achieved in 60 min of treatment. At the concentrations tested here, however, it is still not efficacious enough to qualify as an EPA-registered sanitizer for swimming pools (requires 6-log kill of E. coli, ATCC 11229, and Enterococcus faecium, ATCC 6569, in 30 s).