Photocatalytic degradation of humic acid on oxalate-pyrite/chitosan

Abstract

In this research, the integrated photocatalyst-adsorbent (IPCA) formulation was built using oxalate-pyrite as the photoactive component and a chitosan as the adsorbents to degrade humic acid under visible light irradiation. The IPCA was synthesized by mixing the oxalate-pyrite powder catalyst with chitosan solution. The beads of IPCA were synthesized using the phase inversion method. Besides, the synthesized IPCA was characterized using Fourier Transform Infrared (FT-IR), Scanning Electron Microscope (SEM), X-ray diffraction (XRD) and UV-visible NIR spectrophotometry. Then, the impact of factors such as the IPCA dosage, initial humic acid concentration and pH on the removal of humic acid was studied. The FTIR and SEM results show that the oxalate-pyrite and chitosan were successfully integrated while the UV Vis NIR result shows that the synthesized IPCA able to absorb visible light. Besides, the photocatalytic activity results show that an increase in the initial concentration from 20 ppm to 100 ppm decreased the removal efficiency from 80 % to 35 % while increase the IPCA dosage from 50 mg/l to 150 mg/l increased the removal efficiency from 20 % to 80 %. The optimum pH was at 9 which resulted 90 % removal efficiency. Moreover, the removal efficiency using oxalate-pyrite/chitosan was 80 % higher than pyrite/chitosan. As conclusion, the oxalate-pyrite/chitosan able to be a potential catalyst for the waste water treatment by photocatalytic reaction method.