Tertiary treatment of coke plant effluent by indigenous material from an integrated steel plant: a sustainable approach.

Biological process is an important and integral part of the coke plant wastewater treatment. Increasing pressure to meet more stringent discharge limits has led to adopt tertiary treatment for biologically treated coke plant (BTCP) effluent which contains intense colour along with many residual toxic pollutants like phenol, cyanide, thio-cyanate and COD. A sustainable process has been developed to remove these pollutants from BTCP effluent by using an indigenous material coke breeze which is abundantly available in integrated steel plant. Based on the developed process, a full-scale (200 m3/h) treatment plant has been designed for installation. The designed data has been obtained from a continuous demo plant treating 10 m3/h BTCP effluents. The utilised coke breeze is entirely used for sinter making. The process is highly efficient for the removal of colour above 95% and other residual pollutants like phenol, cyanide and COD to a safe level for discharge or reuse. This process neither incurs any additional chemical cost nor generates any secondary pollutants or products. Moreover, the developed process is very sustainable as it has some great advantages like less investment and low maintenance cost; therefore, the method is good in economics. The treated wastewater contains very less amount of chemical residues therefore meets the standards for reuse as industrial water resource. Hence, this developed technology has significant economic, social and environmental benefits. Graphical Abstract .