MANAGEMENT OF VIRAL RISK IN WATER BY COLIPHAGE

Abstract

Indicator function of coliphage in regard to viral pollution control was investigated. Concentration of cbliphage in night soil was in the range from less than 10 to 10⁶ PFU·mL^-1. In sewage, coliphage concentration ranged from 10² to 10³ PFU·mL^-1. Calculation based on the concentration in sewage showed that coliphage concentration in night soil should be 1-10⁵ times more than in actual night soil. In diluted night soil, coliphages didn't multiply but they could multiply in diluted night soil when easily assimilable organic matter for host bacteria was added. Suppression of FRNA phage multiplication by RNase was also investigated. RNase inactivated FRNA phage Qβ only at the moment of infection. Some ingredient in night soil decreased efficiency of plating of Qβ by about 15% but did not affect T4 concentration measurement. Coliphage in night soil must multiply after diluted and added some organic matter in sewer pipes. Coliphage concentration, greatly affected by organic matter in the environment, can be assumed to be an indicator for sewage pollution rather than night soil pollution. Both DNA phage and FRNA phage can be applied to the indicators of viral removal in water treatment process, and only FRNA phage can be applied in wastewater treatment process because DNA phage tends to multiply in wastewater treatment process.