Inactivation of faecal indicator micro-organisms in waste stabilisation ponds: interactions of environmental factors with sunlight

摘要: Sunlight exposure is considered to be the most important cause of “natural” disinfection in waste stabilisation ponds (WSPs). We examined influence dissolved oxygen (DO), pH, and particulate constituents WSP effluent, on sunlight inactivation faecal micro-organisms, using small reactors operated under controlled physico-chemical conditions. Inactivation both enterococci F-RNA phages increased strongly as DO was increased, also depended light-absorbing pondwater constituents, but pH not influential over range investigated (7.5 10). E. coli when above 8.5, well being dependent DO. F-DNA phage independent factors investigated. These results are consistent with inactivated a result direct DNA damage by UVB sunlight, whereas other three microbiological indicators photo-oxidative damage, although target apparently different. Our findings diverse influences conditions suggest difficulties interpreting data for single micro-organism indicate effluent quality. However, remains factor over-riding importance, WSPs may enhanced increasing exposure.