Enzymatic Treatment of Pharmaceuticals and Personal Care Products in Wastewater

Conventional wastewater treatment plants are not designed to remove pharmaceuticals and personal care products (PPCPs), allowing them to enter natural waters, usually upstream of drinking water sources. Therefore, these recalcitrant compounds are of both ecological and human health concern. This research aims to develop and demonstrate the feasibility of an enzymatic wastewater treatment process for PPCP removal. Experiments have been conducted to evaluate laccase-catalyzed oxidation of oxybenzone, a representative PPCP. Based on mediator screening experiments, two mediators were selected for further study. The laccase– mediator system yielded complete removal of oxybenzone (below the detection limit) from municipal wastewater primary effluent at an environmentally relevant concentration of 10 μg/L. Implementing enzymatic treatment before biological treatment, which is not feasible for alternative treatment processes, provides the opportunity for oxidation byproducts to be removed in the activated sludge process. The byproducts generated during enzyme oxidation of oxybenzone were characterized.