Electrochemical treatment of real cotton fabric industry wastewater using copper and stainless steel electrodes

Real cotton fabric industry wastewater (CFIWW) was treated using the novel electrochemical coagulation (ECC) technology by stainless steel (SS) and copper (Cu) electrodes for applied cell current 1.5 and 4.4 A for a maximum electrolysis time of 30 min. Pre-characterization of CFIWW before ECC showed higher values of chemical oxygen demand (COD), colour, chloride, alkalinity and other quality parameters. Removal of COD and total dissolved solids (TDS) were 97 and 94% for 30.2 V and 4.4 A while using a Cu electrode. The ECC obtained sludge produced 3.13 g/L for Cu and 11.2 g/L for SS for 4.4 A, and 0.43 and 3.98 g/L for 1.5 A. The analysis of ECC sludge was conducted using a scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier-transform infrared spectroscopy (FT-IR). The SEM images of ECC sludge showed unstructured, irregular morphology with uneven edges and rough surfaces. The elemental composition of sludge was studied using EDS showing the presence of copper, oxygen, sodium, sulphur and iron. The FT-IR spectra of ECC sludge for Cu- and SS-mediated ECC-generated sludge showed the presence of alcohol and carboxyl groups at several wave numbers. The specific energy consumption (SEC) for Cu was lower than SS.