PERACETIC-ACID DISINFECTION OF SECONDARY EFFLUENTS DISCHARGED OFF COASTAL SEAWATER

Peracetic acid (PAA), a well known powerful antimicrobial agent in hospitals and in agribusiness (Fraser, 1986), has recently been used to disinfect urban effluents. It appears to be highly competitive against chlorine (Audic, 1990 ; Baldry, French, Slater and Desprez, 1990 ; Giodani, Iacoponi, Polidori, 1989), the most widely used disinfectant for sewage disposal. As PAA is a new biocide, not much quantitative data is available on its action against the faecal indicator bacteria and viruses An on-site experimental study investigated the disinfectant action of PAA against these indicator bacteria and viruses as well as against Salmonella and enterovirus. To complete this study we will test its action on suspended solids to find out whether there is regrowth of the microorganisms after treatment. Multi-factor analysis in terms of criteria like inactivation efficiency, safety environmental impact, and cost will be used to compare PAA to chlorination and ozonation, the most commonly used techniques.