Antimicrobial contaminant removal by Multistage Slow Sand Filtration: Fid-Bau Portal

Antimicrobial contaminant removal by Multistage Slow Sand Filtration

Rooklidge, Stephen J. / Miner, J. Ronald / Kassim, Tarek A. / Nelson, Peter O.

In rural areas, where passive filtration of surface water is a viable option, aquatic systems can become contaminated by antimicrobials from wastewater treatment plants or diffuse pollution. This study examined slow sand filter biomass (schmutzdecke) sorption behavior and removal efficiencies in a pilot roughing and slow sand filter that was fed 0.2 mg/L of five compounds from four classes of antimicrobials. High‐performance liquid chromatography/tandem mass spectrometry (HPLC MS/MS) was used to analyze aqueous antimicrobial concentrations. Schmutzdecke sorption coefficients were comparable to those previously found for soils but did not correlate well with estimates derived from octanol–water partition coefficients. Roughing filtration exhibited low removal efficiencies, but antimicrobials with high sorption coefficients can accumulate in roughing filter waste and schmutzdecke. At the end of a 14‐day slow sand filtration period, tylosin was not detected in filter effluent and trimethoprim was >99% removed. Slow sand filtration, however, exhibited <25% removal of lincomycin and <4% removal of the sulfonamide class of antimicrobials. Multistage filtration is regarded as an ineffective treatment method for antimicrobials with low filter‐media sorption coefficients.