Removal of Color and COD from Olive Wastewater by Using Three-Phase Three-Dimensional (3D) Electrode Reactor

Abstract

The effect of different catalysts on the oxidation of olive wastewater (OMW) was investigated by using an electrocatalytic system. In this study, TiO2/AC, V2O5/TiO2/AC and WO3/TiO2/AC (over activated carbon) catalysts were prepared by a sol-gel method in aqueous solution. The oxidation process was optimised by investigating of the effects of different parameters, for example, time, voltage, suspension's pH and the type of used catalysts. Optimum values for these detected parameters were found 90 min., 20 volts, 5.0, and 1.0gL(-1) respectively. All experiments were carried out in the stability of constant at room temperature. During the experiment, samples were periodically taken and color and chemical oxygen demand (COD) change in aqueous wastewater was analysed to evaluate the efficiency of different catalysts. The results show that after 90 minutes only 80% colour was removed in the presence of cataysts V2O5/TiO2/AC under the same experimental conditions. In addition, the high degradation efficiency of this system is attributed to the synergistic combination of different chemical processes occurring simultaneously, for example, adsorption, electrocatalytic and electrochemical oxidations. (C) 2019 Elsevier Ltd. All rights reserved.