Using NiFe2O4 as a nano photocatalyst for degradation of polyvinyl alcohol in synthetic wastewater

Abstract

The wastewater containing Polyvinyl alcohol (PVA) is white and has water-soluble polymer released from textile and chemical industries. In this research, the degradation of synthetic wastewater containing PVA by the UV/NiFe2O4 method was explored in a batch photo reactor. The NiFe2O4 nano photocatalyst was synthesized by the co-precipitation procedure. The characterization of catalyst was determined by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infra-Red (FTIR) spectroscopy techniques. The stability of nano photocatalyst particles was tested and studied by Zeta potential. The effect of various parameters such as pH, initial concentration of pollutants and the dosage of catalyst on degradation of PVA was inspected. About 94.3% of PVA and 41.3% of Chemical Oxygen Demand (COD) was removed after 140 min of treatment at optimum conditions (0.3 g/l of catalyst, 25 mg/l of PVA and pH at 6). The reason for the formation of active radicals in photocatalytic processes was the electron-hole mechanism. The kinetic of the PVA degradation was explained based on the Langmuir Hinshelwood model and the apparent rate of the pseudo-first-order reaction (Kapp=2.06×10−2min−1) and the half-life of the reaction (t1/2=33.6min) was achieved.