REDUCTION OF MICROBIAL LEVELS IN SEWAGE EFFLUENTS USING CHLORINE AND PERACETIC-ACID DISINFECTANTS

The application of the EC Bathing Water Directive to the quality of marine waters used for recreation in the UK has shown that a substantial number of popular bathing places are contaminated with sewage and sewage effluent. The presence of microbes at levels in excess of the EC Directive standards has resulted in a commitment by UK water companies to invest heavily in the treatment of sewage at coastal locations prior to sea discharge. This study reports on the bench scale disinfection of secondary effluent using disinfectants based on chlorine and peracetic acid. Under the experimental conditions used, both bacteria and viruses were reduced substantially by a chlorine-based disinfectant. The reduction of bacteria by a peracetic acid compound was at least as good as that with the chlorine material but virus reduction was markedly lower.