The Efficacy of Natural Wastewater Treatment Systems in Removing Faecal Indicator Bacteria
This project sought to determine the efficacy of natural systems in removing faecal indicators The most effective systems achieve Escherichia coli concentrations in the range 102-103 cfu 100ml-1 which is comparable to UV treatment. However, there is little data on attenuation during normal changes in flow. The systems studied included a horizontal reedbed, vertical reedbeds (which were relatively immature), a lagoon and integrated constructed wetlands (ICW). E. coli dry weather attenuation rates across the plants were found to vary between 70.2% and 99.8%. Corresponding wet weather attenuation varied between 55.8% and 99.9%. For enterococci, the dry weather attenuation varied from 61.12% to 99.8% and the wet weather attenuation varied from 3.9% to 99.8%. E. coli was attenuated more than intestinal enterococci. The integrated constructed wetland produced the highest attenuation of faecal indicator organisms followed by the retention lagoon, then the horizontal reedbed with the vertical reedbed producing the lowest attenuation.
|UKWIR Reference :- 05/WW/21/7||Published Date :- 25/07/2005|
|Retail Price (£) :- 16||ISBN :- 1-84057-385-6|