A Literature Review of the Efficacy of Natural Systems in Removing Faecal Indicator Bacteria
Two wetland types have been distinguished according to the presence of a free water surface. This feature determines the extent to which key processes, including oxygen diffusion and the balance of removal mechanisms between sedimentation and sieving, will operate. Removal of faecal indicator organisms and pathogens has been represented as a two step process, where initial retention is followed by elimination. Short-term by-pass and channelled flow, which might occur during storm-events, represents a potential problem to operational efficiency. Despite this fact, almost no intensive, event-based, sampled data exist. The majority of studies rely upon infrequent (weekly or longer) paired sampling of influent and effluent flows which are likely to be biased towards more stable flow conditions. Few data quantify seasonal changes to FIO and pathogen populations within individual wetlands. Thus, the principal data gap is event-based faecal indicator flux assessment to assess impacts on 'protected areas' such as bathing waters.
|UKWIR Reference :- 05/WW/21/5||Published Date :- 10/05/2005|
|Retail Price (£) :- 100||ISBN :- 1 84057 375 9|