Chlorine demand of biofilms in water distribution systems

Fixed biomass (biofilms) chlorine demand, produced from 3 test waters, is s tudied by the means of two methods: directly on colonized plastic beads and indirectly on biomass extracted after sonication. The first method results show that a steady state of biomass formation can be reached after an incu bation period depending on test water quality. At steady state biofilms chl orine demand increases linearly with BDOC of water and increases according to the ratio surface/volume. The second method results show that extracted biomass chlorine demand it; related with protein concentration and heterotr ophic plate counts level in the extracts. (C) 1998 Elsevier Science Ltd. Al l rights reserved.