Decolorization, COD and turbidity removal of the raw vinasse effluent by a one-step electro-oxidation process on a Pb/PbO2 anode

Abstract

In this research, and for the first time, the application of anode Pb/PbO2 (prepared from combined thermal oxidation and electrochemical oxidation method) and steel cathode in a flow sample electrochemical treatment process of vinasse and in the wastewater of alcohol factories, has been investigated. The combination of electrodes of Pb/PbO2 as an anode, steel, and/or graphite as a cathode was used in the proposed electrochemical treatment setup. The efficiency of the proposed electrochemical treatment was determined by the removal percentage of chemical oxygen demand (COD), turbidity and color of vinasse samples. The response surface method (RSM) by Minitab 18 was used to determine the effect of the studied factors as well as to detect the relationship between variables. The results showed that under optimum conditions (Pb/PbO2 electrode as the anode and steel electrode as the cathode, a voltage of 30 V, pH 6.5, and reaction time of 45 min), the percentage reduction values of COD, turbidity and color were 97.7, 77.3 and 92.7%, respectively. HIGHLIGHTS Removal of organic pollutants from vinasse through indirect oxidation to CO2 and H2O.; Designing a simple laboratory electrochemical system for the purification of raw vinasse.; Treatment without sample pretreatment, dilution and addition of auxiliary reagents.; Reducing the poisoning of the electrode surfaces by the circulation of raw vinasse.; The possibility of purifying complex matrices (vinasse) with high efficiency in a short period of time.;

Keywords

• alcohol industry
• electrochemical oxidation
• response surface method
• treatment
• wastewater