Breaking down process barriers: ZnSe/CdSe composite catalysts drive enhanced catalytic properties and modified membrane structures for removing humic acid from aqueous environments

Abstract

In the present research, with the aim of removing humic acid from wastewater, photo-catalytic membrane reactor was utilized. Single-component catalysts including ZnSe, CdSe, as well as composite catalyst (ZnSe/CdSe) were deposited in the surface layer of polysulfone membrane via photo-grafting method, whereby ZniCdjM11i and j are ZnSe and CdSe loading concentration level membranes were synthesized. The results indicated that the ZnSe/CdSe due to its shorter bandgap, had a more effective role in the grafting process and hence adjusting the membrane pore size. The pore size of Zn4Cd4M was smaller than that of Zn4Cd0M and Zn°Cd4M, and hence the humic acid separation in the dark mode by Zn4Cd4M was 80 %, which is about 10 % greater than the value obtained by Zn4Cd0M and Zn°Cd4M. The ZnSe/CdSe due to its less photoluminescence emission, proved to be more effective in photocatalytic reactions compared to the single component catalysts. The extent of photocatalytic degradation of humic acid in the presence of UV-radiation by the Zn°Cd4M, Zn4Cd0M, and Zn4Cd4M was reported 80, 84, and 96 % respectively. Overall, due to the smaller pore size, shorter bandgap, and lower recombination, TOC removal by the Zn4Cd4M (containing composite catalyst) was reported 98 %, while this value for the Zn4Cd0M and Zn°Cd4M was reported 60 and 66 % respectively.