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Title: Wastewater disinfection field trials (231/4/SW)
Author: M. Adams
Author: B. Roddie
Author: G. Realey
Author: D. Brogden
Author: R. Butler
Author: M. Crane
Document Type: Monograph
This report describes work investigating the efficacy and environmental impact of some sewage disinfection methods in full scale field trials. Water Utilities are considering disinfection of screened sewage outfalls or secondary effluent discharges from coastal or inland sewage treatment works, as the NRA take steps to enable bathing waters to meet EC bathing water directive standards and protect bathers from pathogenic micro organisms. Three aspects of sewage disinfection were considered. Firstly, by product formation of disinfection, secondly the ability of the disinfectants to reduce the numbers of both indicator and potentially pathogenic micro organisms, and lastly the ecotoxicity of sewage before and after it had been disinfected. There were three full scale field trials in 1990. The first looked at the efficacy and effects of ultraviolet radiation on a secondary effluent from a sewage treatment works. The other two studied the effects and impact of peracetic acid, on a fine screened raw sewage discharge and a biologically treated effluent respectively. Overall, ultraviolet light looks a promising method for disinfecting secondary effluent, though there is a need for more work in the field on the potential for photoreactivation of indicator micro organisms and on the disinfection efficacy for target potential pathogens. The work on peracetic acid did not suggest that it performed well as a disinfectant of fine screened sewage, though it seemed to be generally effective against indicator micro organisms in effluent that had previously received full secondary biological treatment. The secondary effluent work cast doubt on the ability to accurately monitor and maintain peracetic acid at required concentrations. All three trials demonstrated the need to develop non routine microbiological analysis techniques for potentially pathogenic bacteria and viruses as they relate to sewage, effluent and environmental waters.
Publisher: National Rivers Authority
Publication Date: 1992
Publication Place: Bristol
Subject Keywords: Sewage treatmentEffluentsWater qualityBathing Water DirectiveWater industryEnvironmental monitoringEcotoxicology
Geographic Keywords: CornwallSt Austell (Cornwall)Pentewan streamWest Cornwall and the Fal catchment
Extent: 122
Total file downloads: 268

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