| Worldwide environmental detections of pharmaceuticals and personal care products (PPCPs) have raised concern about potential environmental and human health impacts. PPCP detections also impede public acceptance of water recycling, which could otherwise mitigate water shortages.;In this study, the efficiency of biofilm-based treatment for removing fifteen PPCPs (biosol, biphenylol, chlorophene, p-chloro- m-cresol, p-chloro-m-xylenol, diclofenac, 5-fluorouracil, gabapentin, gemfibrozil, ibuprofen, ketoprofen, naproxen, phenytoin, triclosan, and valproic acid) from water was assessed in three separate simulations of soil aquifer treatment (SAT; a water recycling method). In each, a set of five laboratory columns was inoculated with wastewater treatment plant effluent and supplied with PPCP-containing media. Effects of primary substrate concentration, secondary substrate concentration, and duration of wetting and drying cycles on biological PPCP removal were examined. Ten PPCPs were removed by more than 95% when supplied without additional carbon or energy sources, suggesting PPCP biodegradability. Primary substrate (acetate) concentrations of 0, 50, and 1000 μg/L affected the biological removals of three PPCPs. Evaluation of the effect of initial PPCP concentration (0.25, 10, 100, and 1000 μg/L) revealed that removal efficiencies of more than half of the tested PPCPs were dependent on initial concentration. An inverse relationship between PPCP concentration and biofilm accumulation was also observed, suggesting PPCP or metabolite toxicity. The duration of wetting and drying times (an SAT operational parameter) affected the removal of five PPCPs when cycle lengths of 2 d wetting/ 2 d drying, 6 d wetting/ 6 d drying, and 6 d wetting/ 12 d drying were considered.;The microbial communities present in laboratory columns and a full-scale SAT site were investigated using pyrosequencing. Communities in columns supplied with 0.25 and 10 μg/L PPCPs were significantly different from each other and from the SAT community, whereas SAT samples from three consecutive days of a wetting and drying cycle were similar to each other. The communities contained microbes with wide-ranging metabolic abilities, including aerobes, anaerobes, nitrifiers, and close relatives of demonstrated valproic acid-, triclosan-, and ibuprofen-degraders.;Overall, results from this study suggest that SAT and other biofilm-based water treatment systems have great potential for effectively removing PPCPs from impacted water. |
