Disinfection efficacy of chlorine and peracetic acid alone or in combination against Aspergillus spp. and Candida albicans in drinking water

摘要

The aim of the present study was to evaluate the fungicidal activity of chlorine and peracetic acid indrinking water against various pathogenic Aspergillus spp. and Candida albicans strains. A. nidulansexhibited the greatest resistance, requiring 10 ppm of chlorine for 30 min contact time for a completeinactivation. Under the same experimental conditions, peracetic acid was even less fungicidal. In thiscase, A. niger proved to be the most resistant species (50 ppm for 60 min for complete inactivation).All Aspergillus spp. were insensitive to 10 ppm even with extended exposure (>5 h). Thecombination of chlorine and peracetic acid against Aspergillus spp. did not show synergistic effectsexcept in the case of A. flavus. Complete growth inhibition of C. albicans was observed after about3 h contact time with 0.2 ppm. C. albicans was less sensitive to peracetic acid. Hence theconcentrations of chlorine that are usually present in drinking water distribution systems areineffective against several Aspergillus spp. and peracetic acid cannot be considered an alternative tochlorine for disinfecting drinking water. The combination of the two biocides is not very effective ineliminating filamentous fungi at the concentrations permitted for drinking water disinfection.