AWWA WQTC71429

This study investigated the development of nitrification with pilot-scale biological filters using anthracite/sand and granular activated carbon (GAC)/sand filter media. Sampling ports on the column walls allowed us to examine removal of various water quality constituents over the media depth. During these experiments, sample flow did not exceed 5% of the total flow rate through the filter. Ammonia, nitrite, nitrate, carboxylic acids (CAAs), bromate, and trihalomethanes (THMs) were monitored throughout the depth of media. Results showed that CAAs were removed in the upper portion of the media bed while the removal of ammonia was more distributed throughout the bed. Full conversion of ammonia to nitrate was observed in each of the filters. Bromate removal was witnessed within the filters but ambient influent concentrations were less than 15 µg/L. THMs removal was experienced within the filter; however, the total THMs concentration was less than 16 µg/L. Ammonia removal was not impacted during filter ripening. Includes 20 references, table, figures.