Study of TiO2/Fe3O4-SAC/PVDF membrane for dye wastewater treatment under "double carbon" target

Abstract

In the context of “carbon peaking” and “carbon neutralization”, Fe 3 O 4 -SAC magnetic carbon, a modified material prepared from fouling peat, was used to enhance the effectiveness of polyvinylidene fluoride (PVDF) membranes in treating dye wastewater. Three dyestuffs, methyl violet, malachite green and Congo red, were tested in terms of water flux, retention rate and pollution resistance to investigate the effect of the modified membranes on the treatment of dyestuffs. The optimal performance of the modified membranes was investigated by varying the ion concentration, initial concentration, and pH value. A group of modified membranes (TiO 2 /Fe 3 O 4 -SAC/PVP/PVDF) was made by adding 1.5 wt.% of TiO 2 to the casting solution and then adding different ratios of SAC-Fe 3 O 4 to test the effect. The results showed that when the TiO 2 content was 1.5 wt.% and Fe 3 O 4 /SAC content was 0.2 wt.%, the membranes had the best overall performance and could retain 71.24% of methyl violet, 75.62% of malachite green and 65.72% of Congo red, with fluxes of 827.35, 769.45 and 729.53 L/(m 2 ·h), respectively), and the average Fe 3 O 4 /SAC preparation using 1 kg of municipal sludge can reduce 1.94 kg of CO 2 emission, while using the modified membrane can reduce approximately 0.80~1.49 kg of CO 2 emission per 1 ton of dye wastewater treated.