Combined electrocoagulation and electro-oxidation of industrial textile wastewater treatment in a continuous multi-stage reactor

Abstract

A combined electrocoagulation (EC) and electrochemical oxidation (EO) industrial textile wastewater treatment potential is evaluated in this work. A fractional factorial design of experiment showed that EC current density, followed by pH, were the most significant factors. Conductivity and number of electrooxidation cells did not affect chemical oxygen demand degradation (DCOD). Aluminum and iron anodes performed similarly as sacrificial anodes. Current density, pH and conductivity were chosen for a Box-Behnken design of experiment to determine optimal conditions to achieve a high DCOD minimizing operating cost (OC). The optimum to achieve a 70% DCOD with an OC of USD 1.47/m was: pH of 4, a conductivity of 3.7 mS/cm and a current density of 4.1 mA/cm. This study also shows the applicability of a combined EC/EO treatment process of a real complex industrial wastewater.

The History and Prospective of the AOPs for Environmental Applications in Colombia**

“…Electrochemical : This is one of the AOPs that has been studied by most research groups in Colombia for the treatment of emerging pollutants. It has been coupled with other treatment systems such as photocatalysis, photo‐Fenton, ultrasound and coagulation [65–74] . The groups GIRAB and GDECON (Universidad de Antioquia) [75–82] have contributed in studies about the treatment of contaminants with different electrodes and combination with other AOPs, achieving TOC removals of 100 %.…”

“…The synergistic effect of the electrooxidation process and the agent allowed a significant increase in the degradation rate. It was possible to achieve 99 % phenol degradation, 80 % TOC and 88 % COD degradation [65,66,72] …”

“…It has been coupled with other treatment systems such as photocatalysis, photo-Fenton, ultrasound and coagulation. [65][66][67][68][69][70][71][72][73][74] The groups GIRAB and GDECON (Universidad de Antioquia) [75][76][77][78][79][80][81][82] have contributed in studies about the treatment of contaminants with different electrodes and combination with other AOPs, achieving TOC removals of 100 %.…”

“…It was possible to achieve 99 % phenol degradation, 80 % TOC and 88 % COD degradation. [65,66,72] By other hand, the GAOX (Universidad del Valle, 2011) made the most significant advances regarding to the transfer of this technology. They published an article about distillery wastewater pretreated with a BDD anode, obtaining a TOC removal of 81 %, 88 % of COD and 98 % of color.…”

Personal Care Wastewater Treatment With Electro-coagulation and Electro-oxidation

“…Electro-coagulation and electro-oxidation processes are electrochemical wastewater treatment systems [8]. Electro-coagulation and electro-oxidation processing results in better reductions than other treatments, this applies to textile wastewater [9]. An important factor in the Electrocoagulation and electrooxidation process is the use of electrodes.…”