Electrocoagulation of textile wastewater containing a mixture of organic dyes by iron electrode

Abstract

This study focused on testing the efficacy of iron (Fe) electrode in an electrochemical treatment (electrocoagulation) of wastewater containing a mixture of organic dyes. The mixture consists of the following azo dyes: Acid Black 194, Acid Black 107 and Acid Yellow 116. The present organic dyes are toxic, cause skin and eye irritation and are extremely dangerous to aquatic organisms. The study was conducted on a synthetic wastewater prepared in a laboratory electrochemical reactor. During the research, the impact of the current density, various concentrations of dye and supporting electrolyte, electrolysis duration and pulsed current regime were tracked. The results are shown through color removal efficiency, chemical oxygen demand (COD) removal efficiency, current efficiency, and specific energy consumption. At the initial concentration of dye (gamma=200 mg/L) and concentration of supporting electrolyte (gamma(NaCl)=1 g/L) the color removal efficiency of 80.64% was achieved for 420 seconds of treatment (J=10 mA/cm(2)). At the initial concentration of dye (gamma=50 mg/L) and gamma(NaCl)=8 g/L, the color removal efficiency of 96.01% was attained for 300 seconds of treatment (j=10 mA/cm(2)).