EFFICIENCY OF THE EUROGUARD DOMESTIC WATER-TREATMENT UNIT WITH REGARDTO VIRUSES, PHAGES AND BACTERIA

The reduction in numbers of human viruses as well as bacteria and phag es in water treated by the commercial Euroguard water filter-cum-purif ier for the domestic treatment of drinking water was evaluated. Drinki ng water seeded with laboratory strains of viruses, bacteria and phage s which indicate faecal pollution, as well as sewage-contaminated rive r water and secondary treated waste water containing naturally occurri ng organisms, were passed through the unit which consists of a candle prefilter, activated carbon filter and ultraviolet irradiation compart ment. At the prescribed flow rate of not more than 1 l-min-1, numbers of poliovirus, hepatitis A virus, adenovirus types 40 and 41, rotaviru s SA11, human rotavirus, coliphage MS2, somatic coliphages, Escherichi a coli, Streptococcus faecalis, Clostridium perfringens, total colifor m bacteria, faecal streptococci and the heterotrophic plate count were reduced by more than 99.99% in all waters tested. In all test runs, i ncluding those on secondary waste water which was not intended to be u sed in the unit and represents a ''worst-case'' situation in practice, the quality of the treated water was well within microbiological limi ts of international specifications for drinking water.