Treatment of hospital wastewater effluent by nanofiltration and reverse osmosis

摘要

Considerable concern exists regarding the appearance and effects of trace and ultra tracenpollutants in the aquatic environment. In this context, it is necessary to identify relevant hotnspot wastewater – such as hospital wastewater – and to implement specific wastewaterntreatment solutions. Membrane bioreactor (MBR) technology seems to be a suitablenpre-treatment approach for the subsequent advanced treatment by high pressure membranensystems such as nanofiltration (NF) and reverse osmosis (RO). This paper is based uponninvestigations on the first full scale MBR for separate treatment of hospital wastewater innGermany. In this study an NF as well as an RO module for further treatment of the MBR filtratenwere tested. The removal efficiencies were assessed using the following target compounds:nbezafibrate, bisoprolol, carbamazepine, clarithromycin, ciprofloxacin, diclofenac, ibuprofen,nmetronidazole, moxifloxacin, telmisartan and tramadol. In summary, the results of this studynconfirmed that MBR technology followed by an advanced treatment for trace pollutantnremoval is an adequate approach for specific treatment of hot spot wastewater suchnas hospital wastewater. In particular, it was shown that – comparing the tested NF andnRO – only (a two stage) RO is appropriate to remove pharmaceutical residues from hospitalnwastewater entirely. The recommended yield of the 2-stage RO is 70% which resultsnin a retentate sidestream of 9%. Our investigations proved that RO is a very efficientntreatment approach for elimination of trace pollutants.