Treatment of anticancer drugs in a real wastewater effluent using nanofiltration: A pilot scale study

Although anticancer drugs occur in the aquatic environment at trace concentration levels, these drugs might be of environmental concern due to their potent mechanism of action. Hence, new treatment technologies should be explored and, if necessary, conventional wastewater treatment plants (WWTPs) should be upgraded to avoid the release of these drugs into the aquatic environment. The effectiveness of nanofiltration to remove six anticancer drugs from wastewater effluents was assessed by installing a pilot unit with a Desal 5DK membrane at a domestic WWTP. Of the target anticancer drugs, only capecitabine, cyclophosphamide and ifosfamide were detected on the feed samples and thus, the removal efficiency was only evaluated for these drugs. Several 4-hour assays were conducted to explore the conditions that would maximize the rejection of the detected compounds and minimize fouling. Rejections higher than 96% were obtained in all the experiments for the detected compounds, independently of the operating conditions tested. Working under a controlled transmembrane pressure of 6 bar and recovery rate of 73% minimized fouling. A 24-hour assay was then conducted under these conditions and a minimal decay on permeability was observed. Samples were collected over time and rejections higher than 94% were obtained for all the detected drugs. None of the samples induced a significant immobilization effect in Daphnia Magna after 48 h of exposure.