A modified membrane filtration-ultraviolet photocatalytic system for the removal of trace sulfadiazine in drinking water (No. CHEM77354R1).

In this paper, the membrane filtration-photocatalytic coupling process was used to explore the mechanism and removal effect of trace concentrations of sulfadiazine (SD) in drinking water. First, 8 kinds of ultrafiltration membranes were successfully prepared, and their performance was verified by scanning electron microscopy and measurement of the contact angle, membrane pure water flux, porosity and average pore size. The results showed that the best-performing membranes were the PVDF-PP-TiO-DA (dopamine) (PPTD)- and PVDF-PP-TiO-FeCl (PPTFe)-modified ultrafiltration membranes, in which TiO was modified with DA and FeCl, forming the cooperation of TiO/DA and TiO/Fe, with removal rates of 91.4% and 92.6% and quasi-first-order rates of 0.0216 min-1 and 0.0214 min-1. At the same time, the effects of the two types of membrane, UV light and water quality characteristics on the removal performance of the membrane filtration-photocatalytic system were discussed. Among them, the PPTD membrane was more suitable than the other membranes for the degradation of weakly alkaline water containing SD (pH = 7.5), except when NO was present, and the water quality characteristics had a significant inhibitory effect on the removal effect. The PPTFe membrane was more suitable for the degradation of acidic water containing SD (pH = 3). Additionally, the water quality characteristics had an obvious inhibitory effect on the removal effect, and the accuracy of the water distribution experimental results was verified by using an actual body of water. In the end, the reaction mechanism of the filtration-photocatalytic system was proposed, and it was found that OH played an indispensable role in the removal of SD.