Abstract
Increase in water use has required an understanding of the inactivation process or survival mechanism of entric viruses in natural waters for preventing waterborne diseases due to pathogenic viruses. The fate of virus in an oxidation pond (in Bangkok, Thailand) was investigated using coliphage (host cell: E. coli B) as an indicator of virus. Batch experiments showed the adsorption of coliphage to the microbial particulates (mainly algae) occured in aerobic conditions. The desorption of coliphage from the particulates was observed under anaerobic conditions. The adsorption-desorption process was reversible and was controlled by dissolved oxygen concentration. The same mechanism of adsorption-desorption was observed in the oxidation pond. The degree of inactivation of coliphage in the oxidation pond (design retention time=20 days) was 90%(1 log). Survey with submerged bottles in the oxidation pond and sunlight-expose experiment using beakers showed that coliphage would be inactivated by sunlight only near water surface (less than 10cm depth at the deepest estimate) in the oxidation pond.
