抄録
The performance of ultra membrane filtration to reject viruses in activated sludge suspension was examined by laboratory experiments. Coliphage T1 and coliphage Qβ were applied as models of infectious viruses, and 4 type's ultra membrane filters were used in the experiments.
The rejection rate of coliphage is affected by the cut off molecular weight of ultra membrane filters, size of coliphages and resistance values (Rcg) of cake- and gel-layers. In the loosest ultra membrane filter used, coliphage T1 was not permeated at the filtration condition that develops the cake- and get-layers with Rcg of 5×1012m-1 and more. In the case of coliphage Qβ, the Rcg was 1×1013 m-1 and more.
When the concentration of viruses is 5.2×103 PFU·l-1 in the treated wastewater by the activated sludge process and the inactivated rate of viruses of 99.9% is reached by chloriration process, the introduction of ultra membrane filtration process for liquid-solid separation can produce the fecal effluent with 5.2×10-5 PFU·l-1 of viruses. In this condition, the health risks caused by viruses is calculated to be 5.2×10-5.
