Preparation and characterization of nano-filtration and its photocatalytic abilities via pre-coated and self-forming dynamic membranes developed by ZnO, PAC and chitosan

Abstract

Abstract In the current work, novel dynamic membranes (DM) were tested and introduced for cheese whey wastewater treatment based on resistant and inexpensive materials, polyesters, and chitosan. For the investigation of dynamic membrane (pre-coated and self-forming) characterizations, polyester as a low-cost and natural material with chitosan were chosen to provide the support of the target membrane. The inherent antifouling character of chitosan accompanied by its high hydrophilicity have made this polymer known as an attractive agent for membrane-based wastewater treatment operations. Zinc oxide (ZnO) and powdered activated carbon (PAC) were employed as the dynamic layer. Neat polyester had a chemical oxygen demand (COD) rejection ratio of about 57.61%, but the flux declined sharply. The higher removal efficiency was for the self-forming type: total phosphate (94%) and citrate (95.5%). Fouled dynamic membranes were backwashed by sodium dodecyl-sulphate (SDS), warm water, and distilled water. Results demonstrated that the pre-coated was reduced and fouling increased the flux recovery rate (FRR) (9.1%) while use of the self-forming DM exhibited an aggravation of fouling by decreasing of support FRR (11.1%). It was found that by substitution of deionized water and hot water with SDS, FRR was enhanced. In the following, the photocatalytic ability of the product was investigated. The UV light source increased the removal ratio and FRR. For example, self-forming COD rejection was enhanced (6.63%).