Combining chlor(am)ine-UV oxidation to ultrafiltration for potable water reuse: Promoted efficiency, membrane fouling control and mechanism

Abstract

Wastewater reuse has been progressively popular as a practical method for protecting aquatic environment and water sources. In this work, the chlor(am)ine-UV oxidation was employed to enhance membrane system performance during potable water reuse. The achievements were comprehensively evaluated from the aspects of membrane fouling mitigation and organic matter removal. The various dosages of chlorine and UV irradiation were applied and the effects of typical inorganic species in wastewater effluent were considered as well. It was suggested that the chlor(am)ine-UV oxidation could significantly promote the normalized flux by 94.9% under the condition of 10 mg L-1/960 mW cm-2 (chlorine dose and UV irradiation density). And the certain lower concentration of inorganic pollutant in wastewater effluent could further prevent the membrane fouling accumulation, especially for the reversible and total fouling resistances. The model fitting of filtration flux revealed that the combination of pore blockage and cake filtration was responsible for the mechanisms of fouling formation, and the transition moment was adjusted by the oxidation process. The characteristics of dissolved organic matter were modified as well, which were positive for the improvement of membrane effluent quality and security. The results demonstrated that the combination of the chlor(am)ine-UV oxidation and ultrafiltration could be a promising alternative for efficient wastewater recycle and reuse.