TREATMENT OF SYNTHETIC DYE WASTEWATER BY COAGULATION AND COAGULATION AIDS

One of the major causes of water pollution is the wastewater generated by different industries like textile, detergents, food and others dealing with daily life products. As environmental protection has become a global concern, industries are finding novel solutions for developing such technologies which reduce the risk of this problem. Coagulation is an efficient technique employed for the removal of dyes from wastewater by using different compounds as coagulants. The work presented here was focused on the removal of orange C2RL dye by using the iron salts. The coagulants were applied to optimise different operational parameters. The Fenton and Fenton-like oxidation reactions were also applied to investigate the removal of Orange C2RL. Results revealed that coagulation was found to be effective in decolourisation nearly 94.29-96.92% using FeCl3 and 63.08-71.25% using FeSO4 at their inherent pH. Decolourisation efficiencies were 83.20% for the Fenton and 75.76% for the Fenton-like oxidation. Colour removal efficiencies were increased up to 95% after the sequential treatment. In addition, calcium salts added in small amount as aids also increased the decolourisation index. Sequential coagulation-oxidation treatment is found to be a viable technique to decrease the colour, COD and TOC amount effectively.