Comparison of two treatments for the removal of selected organic micropollutants and bulk organic matter: conventional activated sludge followed by ultrafiltration versus membrane bioreactor

摘要

The potential of membrane bioreactor (MBR) systems to remove organic micropollutants wasninvestigated at different scales, operational conditions, and locations. The effluent quality of thenMBR system was compared with that of a plant combining conventional activated sludge (CAS)nfollowed by ultrafiltration (UF). The MBR and CAS-UF systems were operated and tested innparallel. An MBR pilot plant in Israel was operated for over a year at a mixed liquor suspendednsolids (MLSS) range of 2.8–10.6 g/L. The MBR achieved removal rates comparable to those of anCAS-UF plant at the Tel-Aviv wastewater treatment plant (WWTP) for macrolide antibiotics such asnroxythromycin, clarithromycin, and erythromycin and slightly higher removal rates than thenCAS-UF for sulfonamides. A laboratory scale MBR unit in Berlin – at an MLSS of 6–9 g/L – showednbetter removal rates for macrolide antibiotics, trimethoprim, and 5-tolyltriazole compared to thenCAS process of the Ruhleben sewage treatment plant (STP) in Berlin when both were fed withnidentical quality raw wastewater. The Berlin CAS exhibited significantly better benzotriazolenremoval and slightly better sulfamethoxazole and 4-tolyltriazole removal than its MBR counterpart.nPilot MBR tests (MLSS of 12 g/L) in Aachen, Germany, showed that operating flux significantlynaffected the resulting membrane fouling rate, but the removal rates of dissolved organic matternand of bisphenol A were not affected.