Removal of Organics and Degradation Products from Industrial Wastewater by a Membrane Bioreactor Integrated with Ozone or UV/H2O2 Treatment

The treatment of a pharmaceutical wastewater resulting from the production of an antibacterial drug (nalidixic acid) was investigated employing a membrane bioreactor (MBR) integrated with either ozonation or UV/H2O2 process. This was achieved by placing chemical oxidation in the recirculation stream of the MBR. A conventional configuration with chemical oxidation as polishing for the MBR effluent was also tested as a reference. The synergistic effect of MBR when integrated with chemical oxidation was assessed by monitoring (i) the main wastewater characteristics, (ii) the concentration of nalidixic acid, (iii) the 48 organics identified in the raw wastewater and (iv) the 55 degradation products identified during wastewater treatment. Results showed that MBR integration with ozonation or UV/H2O2 did not cause relevant drawbacks to both biological and filtration processes, with COD removal rates in the range 85–95%. Nalidixic acid passed undegraded through the MBR and was completely removed in the chemical ...