Biodegradability enhancement and pre-treatment of industrial estate wastewater by electro-Fenton process

Abstract

Advanced oxidation processes have been applied as one of the main commonly treatment methods to improve the biodegradability of persistent organic materials, especially in industrial wastewaters. In this study, the chemical oxygen demand (COD) and total oxygen carbon (TOC) removal efficiency and biodegradability improvement of the industrial estate wastewater were investigated by electro-Fenton process (EFP). The influences of various parameters including pH, H2O2 concentration, electrical current density, and reaction time were evaluated on the EFP. The maximum removal efficiency of COD (88) and TOC (80.8) was achieved at optimum pH 4, H2O2 concentration 13.5 mM, current density 5 mA cm(-2), and reaction time 20 min. The optimum H2O2/Fe2+ molar ratio was found to be 2. The biodegradability of the wastewater was increased from 0.23 to 0.39 after treatment by EFP under optimum conditions. The results showed that H2O2/Fe2+ molar ratio was the most important factor in the EFP system. The findings showed that the EFP can be considered as a suitable technique for pre-treatment and biodegradability enhancement of the industrial estate wastewater. So, this wastewater can be easily post-treated by biological treatment methods.