- Thesis topic: Simultaneously Photocatalytic and Peroxysulfate, Hydrogen Peroxide Activation Processes by CuO@ZnO Photocatalyst Coating on PVDF Membrane for Degradation of Membrane Fouling

- Doi: 

- Abstract: 

        Due to its high removal efficiency, membrane treatment processes are widely used in water treatment. However, the long-term operation can lead to fouling on the membrane surface, affecting its flux and lifespan. The use of Peroxysulfate (PMS) and hydrogen peroxide (H2O2) activated by photocatalysts has proven effective in degrading organic pollutants in water while enhancing the hydrophilicity and anti-fouling ability of the membrane. Therefore, this study aims to modify polyvinylidene fluoride (PVDF) membranes using synthesized composite photocatalysts (CuO@ZnO) and employing photocatalytic reactions and PMS activation to mitigate membrane fouling.
The CuO@ZnO photocatalyst is coated onto PVDF membranes using a coating method, and PMS and hydrogen peroxide are activated to generate free radicals. The anti-fouling properties of the modified membrane and the flux recovery rate are evaluated through simulated pollutant tests. The photocatalytic performance of different compositions of CuO@ZnO was initially evaluated to determine the optimal composition for membrane incorporation. Experimental results revealed that the 30% CuO@ZnO composite exhibited the highest photocatalytic degradation efficiency, with a final removal efficiency of 25.08% after 70 minutes of UV photocatalysis at a dye concentration of 20 mg/L. The removal efficiency increases to 81.96% with the addition of H2O2 and reaches 99.42% with the addition of PMS as an oxidant.
Due to the smaller particle size of the coated composite photocatalyst compared to the pore size of the membrane, the pure water flux of the prepared photocatalytic membrane (30% CuO@ZnO/PAA/PVDF) decreases by approximately 11.84% compared to pristine PVDF membranes. After modify the photocatalytic membrane, supplemented with PMS as an oxidant, achieves a final removal efficiency of 97.26% under UV irradiation for 70 minutes at a dye concentration of 10mg/L, And after five cycles, the removal rate was still higher than 77%, although there was a slight decrease. Anti-fouling experiment using sodium alginate as a pollutant, the flux recovery rate (FRR%) of the modified photocatalytic membrane reaches 95.63%. These results indicate that the modified photocatalytic membrane (30% CuO@ZnO/PAA/PVDF) in this study exhibits high anti-fouling performance and is highly applicable in wastewater filtration and separation processes.

Keywords: Photocatalytic reaction, composite photocatalyst, CuO@ZnO, Peroxysulfate (PMS), polyvinylidene fluoride (PVDF), anti-fouling membrane.