Removal of pharmaceuticals and endocrine disrupting compounds in a water recycling process using reverse osmosis systems
A detailed investigation was carried out to evaluate the occurrence, persistence and fate of a range of micropollutants at different processing points at a full-scale water recycling plant (WRP) in Queensland, Australia. The WRP, which combines an advanced water treatment plant (AWTP) with a wastewater treatment plant (WWTP), produces high quality recycled water for industrial users. The concentrations of 11 pharmaceuticals from various therapeutic categories and two endocrine disrupting chemicals were examined in full-scale microfiltration and reverse osmosis membrane facilities. Salicylic acid was the most abundant analyte in the WWTP influent, with a concentration range of 11–38 μg/L, followed by bisphenol A with concentrations ranging from 6 to 23 μg/L. The concentration of all analytes decreased on average by one order of magnitude following primary and secondary treatment. Gemfibrozil, primidone and carbamazepine were found to have lower removal efficiencies (74–78%) than other compounds during these stages, which could indicate lower biodegradability. The microfiltration and reverse osmosis systems were found to further lower the pollutant concentrations by an order of magnitude. The overall removal efficiencies in the final recycled water were above 97%, resulting in product water concentrations of lower than 0.1 μg/L for most compounds. An exception to this finding was observed for bisphenol A, which was detected in concentrations up to 0.5 μg/L in the final recycled water.