Catalytic ozonation membrane reactor integrated with CuMn2O4/rGO for degradation emerging UV absorbers (BP-4) and fouling in-situ self-cleaning

Abstract

• The combination of CuMn 2 O 4 and rGO enhanced the catalytic ozonation. • Coating times and calcination temperature determined catalytic membrane properties. • [Ozone] and TMP affected the degradation of micropollutants significantly. • Self-cleaning and catalytic ozonation are catalytic ceramic membrane superiority. To develop degradation efficiency of emerging ultraviolet absorbers (benzophenone-4, BP-4) and in-situ self-cleaning of membrane fouling in membrane filtration, a novel CuMn 2 O 4 /rGO catalytic ceramic membrane (CR/CM) was fabricated and used in catalytic ozonation membrane reactor (COMR) for water purification. Firstly, the CuMn 2 O 4 /rGO powder catalyst was optimized, according to the performance of catalytic ozonation BP-4. After that, the potential reaction sites was proposed as surface oxygen defect in CuMn 2 O 4 /rGO. Secondly, the optimized CuMn 2 O 4 /rGO powder was deposited on the surface of ceramic membrane by the vacuum negative pressure method. The thickness and roughness of the active layer were adjusted by changing the coating times. The best fabrication condition was twice surface coating. The performance of this CR/CM mainly depended on [ozone] and transmembrane pressure (TMP). The optimum reaction parameters were [ozone] = 20 mg/L and TMP was 0.20 bar. Compared with the pristine ceramic membrane coupled with ozonation, the degradation efficiency of BP-4 increased by 61.3%, the self-cleaning efficiency of catalytic membrane was 52.87%. The proposed COMR, gave a full play to the respective advantages of membrane filtration and catalytic ozonation technology, including degrading micro-organic pollutants effectively and alleviating membrane fouling.