Treatment of Dye Effluent by Electrochemical and Biological Processes

Textile dye wastewater is well known to contain strong colour, high pH, temperature, Chemical Oxygen Demand (COD) and biodegradable materials. The electrochemical treatment of wastewater is considered as one of the advanced oxidation processes, potentially a powerful method of pollution control, offering high removal efficiencies the removal of colour of methyl red azo dye is a challenge in textile industry. The following methods have been adopted for the treatment of real textile wastewater: 1) Electro-oxidation (EO) and 2) Bio-treatment (BT). In EO process, reduction of COD and removal of colour were 70% and 81% respectively. The effluent was further treated by BT. BT showed a final reduction of 92% of COD and removal of colour by 95%. Both the combined processes were highly competitive and showed a very good reduction of COD and colour removal. Electrochemical processes generally have lower temperature requirement than those of other equivalent non-electrochemical treatments and there is no need for additional chemicals. These treatment methods may also be employed successfully to treat other industrial effluents.