REDUKTION AV TILLVÄXTBEFRÄMJANDE ÄMNEN VID VATTENVERKET BORG I NORRKÖPING / Reduction of Bacterial Growth Potential in Drinking Water Treatment Processes in Norrköping, Sweden
Measurements of bacterial growth potential were carried out in the drinking water treatment plant and distribution net of the city Norrköping, Sweden. The growth of bacterial biomass was measured with two specific bacterial strains, Pseudomonas fluorescens strain P17 and Aeromonas hydrophila M 800, and with the indigenous bacterial population found in the raw water of the water treatment plant. Nearly 70 % of the organic matter, measured as CODMn, was removed after coagulation. The slow sand filtration increased the removal with 5 %. The reduction of the growth potential, measured as the maximum bacterial count (Nmax), was considerable from the raw water to the filtrate after the chemical percipitation step, more than 90 % for Pseudomonas, near 80 % for Aeromonas and 60 % for the indigenous bacterial population. The following slow sand filter treatment only slightly improved the water quality in this respect, the Pseudomonas value even increased. A seasonal variation of the growth potential was found for all organism groups. “Complete abstract not presented.”