The effects of applied electric charge (0–200 Amp–min) and pH on the removal of colour and COD from textile wastewater have been analysed. Mild steel plates have been used as electrodes in both parallel and series connections. For colour and COD removal, four electrodes each with a surface area of 177.3 cm² and with inter–electrode distance of 2.3 cm in parallel connection have been used. Under the experimental conditions, colour removal (initial concentration 1070 Pt.Co. unit) approaching 100% and COD removal (initial concentration 110 mg/l) of over 50% have been achieved. Removal of both colour and COD increased with increasing electric charge. Removal efficiency of As and Cr form synthetic wastewater sample has also been assessed and very efficient removal was found. Thus, electro–chemical treatment in combination with biological treatment could provide an efficient treatment solution for highly coloured textile wastewater and wastewater containing heavy metals.
Keywords: electrochemical treatment, textile effluent, COD removal, chemical oxygen demand, colour removal, arsenic, chromium, heavy metals, wastewater treatment, biological treatment