Electrochemical treatment of Reactive Black 5 textile wastewater: optimization, kinetics, and disposal study

This research reports treatment of textile wastewater containing Reactive Black 5 (RB5) and other industrial constituents which are found in textile industry effluent, by the electrochemical treatment method using aluminum electrodes. Initial pH, current density (J), and electrolysis time (t) were selected as operational variables to observe the effects on chemical oxygen demand (COD) removal efficiency (Y1), dye removal efficiency (Y2), and specific energy consumed (Y3) (kWh/kg of COD removed). A response surface methodology (RSM) with full factorial central composite design (CCD) was used for designing and optimizing responses. To optimize the multiple responses, multi-response optimization with a desirability function were utilized for maximizing Y1 and Y2, and simultaneously minimizing Y3. To address issues of treated wastewater disposal, aluminum mass balance was performed. Electrocoagulation with subsequent adsorption, electro-floatation, and electro-oxidation were found to be the mechanism for removal of the pollutants.