A Consolidated Stratagem Towards Defenestration of Coke Oven Wastewater Using Various Advanced Techniques—An Analogous Study

Abstract

Coke oven wastewater produced from steel industry contains hazardous constituents like phenols, cyanides, ammonia, SCN−, etc., which needs to be treated before expulsion to the environment. Therefore, pre-treatment of these large volume of wastewater is required for maintaining environmental standards. Simulated coke oven wastewater pertaining to effluent characteristics discharged by industrial sector was synthesized. Initially, treatment of wastewater was performed with ozone which was used in combination with activated carbon (AC) and H2O2 to increase the degradation of COD. The maximum degradation achieved in the O3/AC was 76.8% while in with O3/H2O2, the COD removal was 75.8%. The O3/AC process was found more acceptable in terms of fast rate of COD degradation, time and economy efficiency suitable for handling large volume of wastewater. However, problems of sludge disposal and process hazards diverted the adoption towards microbial treatment using bacterial strain Alcaligenes faecalis JF339228 where phenol was degraded up to 80.88% in 76 h from the coke oven mixture. Due to the high toxicity level of coke oven wastewater, only biological treatment fails to treat them effectively. Combined microbial treatment as well as membrane-based separation process (thin-film composite—reverse osmosis membrane) for wastewater purification was also applied. Thin-film composite (TFC) RO membrane was used to treat this solution at pressure of 200 and 300 psi and at different pH of 5, 7 and 8, respectively. The maximum quantity of phenol removed by TFC RO membrane at 300 psi pressure and pH of 8 was 76%. Thus, an amalgamated approach of bioremediation and reverse osmosis was sustainable.