Effectiveness of Sewage Treatment Based on Selected Faecal Bacteria Elimination in Municipal Wastewater Treatment Plant in Toruń

The sewage treatment plant was monitored to determine the efficiency of technologies employed to reduce microbiological threats. Every four weeks, for a year, sewage was sampled to investigate the effects of post-mechanical and post-biological treatment. Changes in Escherichia coli, D-group streptococci and Salmonella spp. number were analyzed. The reduction of the bacteria in sewage treated mechanically was not significant and did not exceed 1 log. However, a significant reduction in an average number was found. In ad-dition, seasonal variation was found to correlate with the number of each of the selected bacteria groups