Combining fluidized metal-impregnated granular activated carbon in three-dimensional electrocoagulation system: Feasibility and optimization test of color and COD removal from real cotton textile wastewater

Abstract

The present study focused on the treatment of real cotton textile wastewater by combining metal (Al/Fe)-impregnated granular activated carbon (MIGAC) as moving particle electrodes in electrocoagulation, referred to here as the MIGAC-TEC system. The feasibility test clearly indicated that MIGAC significantly accelerated the decolorization and COD removal efficiency. The effects of four parameters: applied voltage, initial pH, MIGAC dosage, and reaction time on the percentage of color and COD removal were investigated using response surface methodology with a central composite design. As results, it was found that the decolorization (R-2 = 0.9576) and COD removal (R2 = 0.9395) were well fitted by a developed quadratic polynomial models and the initial pH was the most influential factor. Through numerical optimization, highly acceptable removal performances of 99.13 +/- 0.21% decolorization and 97.01 +/- 0.18% COD removal efficiency were achieved under statistically optimized conditions, and suggested that the developed system is a very suitable technique for the enhancement of electrocoagulation-based cotton textile wastewater treatment. (C) 2015 Elsevier B.V. All rights reserved.