Effect of hydrogen peroxide on the surface property of polymeric membrane materials in ultraviolet oxidation coupled with membrane filtration process for hospital wastewater treatment

Abstract

The combined process of Ultraviolet (UV)/Hydrogen peroxide (H2O2) and membrane filtration is being studied as an alternative to conventional wastewater treatment facilities due to its advantages such as increased filtration performance and reduced membrane fouling. However, when the UV/H2O2 advanced oxidation process is used as a pretreatment for membrane filtration, research on membrane characteristics variations and performance evaluation is insufficient. In this study, the effects of materials on the membrane filtration process were compared when using UV/H2O2 as a pretreatment process. And, the potential removal efficiency of Effect of hydrogen peroxide on the surface property of polymeric membrane materials in ultraviolet oxidation coupled with membrane filtration process for hospital wastewater treatment 4 chemicals (Caffeine, Atenolol, Acetaminophen, and Chlortetracycline) of Contaminants of emerging concern(CEC) detected in the effluent of public wastewater treatment plants was confirmed through UV/H2O2 pretreatment processes at various dosage. It was confirmed that treated water quality will be improved by the UV/H2O2 process apply to public wastewater treatment plant. Chemical cleaning of the membrane was performed by adding the membrane to 1N HCl and 3000 mg.L-1 NaOCl for 1 hour. Pore size 0.1 μm Polyethersulphone (PES) and Polyvinylidene fluoride (PVDF) ultrafiltration membranes were compared and evaluated for membrane structure variations and filtration performance through membrane filtration during filtration and chemical cleaning in 3 cycles. The removal efficiency of CECs was evaluated using Liquid Chromatography with tandem mass spectrometry (LC-MS/MS) and total organic carbon (TOC) analysis. As a result of CECs removal, chlortetracycline (CTC) showed the highest removal efficiency, followed by atenolol (ATL), acetaminophen (ACT) and Caffeine (CAF) showed the highest removal rate in that order. Membrane fouling analysis for comparative performance evaluation of PES and PVDF membranes was determined by specific fouling and membrane fouling indices evaluation. It was confirmed that when excessive UV/H2O2 dosage, reversible and irreversible fouling worsened caused by interaction between the decomposed CEC and the membrane. Membrane characteristic variations were analyzed by field emission scanning microscopy/energy dispersive spectrometry (FESEM/EDS), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and contact angle measurements via Extended Derjaquin-Landau-Verway- overbeek (XDLVO) theory. As a result of the UV/H2O2 treated solution filtration, it was confirmed that alkyne and carbonyl groups were formed and a variation at the membrane structure occurred, and the reaction of PVDF and PES membranes with oxidizing and chemical cleaning agents showed that the fluorine ratio decreased and the sulfur ratio increased due to defluorination and oxidation. The results of this study suggested the possibility of improving treated water quality by applying the UV/H2O2 advanced oxidation process and ultrafiltration process to public wastewater treatment facilities.