AWWA ACE99506

The objective of this study was to assess the impact of temperature and season on the performance and microbial community structure of biological filters and microbial community, both in bench- and full-scale filters. Many drinking water plants, especially those in the northern part of the United States, Europe and southern part of Canada, experience seasonal temperature variations of 20 to 30?C and therefore, a more in-depth study of the impact of the temperature and season in biofilter performance was needed. To isolate the effect of temperature, a bench-scale study was conducted under rigorously controlled temperatures with all other conditions constant. During this study, rapid sand filters were run at three different temperatures and the removals of dissolved organic carbon, biodegradable dissolved organic carbon, assimilable organic carbon, precursors of total organic halides (TOX), trihalomethanes (THM), six haloacetic acids (HAA6) and chlorine demand under uniform formation conditions (UFC) were monitored. The effect of season was assessed by studying eight full-scale plants during the winter and summer. In the full-scale assessment, the results obtained are the effect of the overall conditions in place at the sampling times.