Optimization of heterogeneous photo-Fenton process parameters by RSM-BBD for decolorization of pulp and paper effluent using Fe₂O₃/TiO₂ catalyst under UV-C irradiation

School of Chemical, Biological, and Materials Engineering and Sciences, Mapúa University, Intramuros, Manila 1002 Philippines

^* Corresponding author: kgnquiton@mapua.edu.ph

Abstract

The pulp and paper (P&P) industry is considered one of the production and manufacturing industries that consume immense amounts of natural resources, such as wood, water, and energy. It is also a significant contributor of pollutants to the environment, where various organic and inorganic contaminants are immensely produced into the environment. In this study, the color removal efficiency from P&P wastewater using a 1.5-L three-phase fluidized-bed reactor in combination with heterogeneous photo-Fenton reaction process was investigated. The process used synthesized Fe₂O₃/TiO₂ catalyst by ultrasonic-assisted impregnation technique and applied UV-C light irradiation for the decolorization treatment of the P&P wastewater. The RSM-BBD was also used to optimize the color reduction efficiency of the P&P wastewater between three independent variables: pH, photocatalyst dose, and H₂O₂ dose. Under the optimal conditions (initial effluent pH = 3, [Fe₂O₃/TiO₂] = 1.25 g/L, [H₂O₂] = 50 mM) with an air flow rate of 2 L min^-1 at a reaction time of 30 min, the color reduction efficiency was achieved as 73.5%. Additionally, pH was found to be the most significant parameter for the decolorization of the P&P wastewater.