Degradation of Congo Red in batik wastewater using fenton reagent under visible rays

Abstract

Congo Red is one of synthetic dyes used in the process of making batik. Batik wastewater which contained Congo red leads to environmental pollution. Fenton reagent can be used to degrade Congo red based on formation of hydroxyl radicals (·OH). Hydroxyl radical is able to decompose Congo red compound through oxidation process. Fenton reagent is a mixture from hydrogen peroxide (H2O2) with Fe2+ ions produced from FeSO4 compounds. The function of visible rays in H2O2/Fe2+ system is to accelerate and increase the formation of hydroxyl radicals. The formation of hydroxyl radicals are affected by pH condition in the solution. The purpose from this research is to degrade Congo red in batik wastewater using fenton reagent under visible rays. The parameters varied were H2O2 concentration, FeSO4 weight and pH. The results showed that visible rays in the system can increase Congo red degradation in batik wastewater. The decrease level of Congo red using fenton/Vis is 63% with added up H2O2 50 ppm, FeSO4 0.2 gram with visible light irradiation for 7 hours. The optimum pH conditions for fenton/Vis system is pH 2 with decrease level of Congo red is 98.19%.