Application of coke breeze for removal of colour from coke plant wastewater

Treatment of coking waste water has always been a challenge because of its complex and toxic nature. Numbers of technologies like biological treatment, advanced oxidation processes, activated carbon treatment etc. are available for removal of color and organic contaminants from wastewater. However, challenges and problems associated with application of biological, advanced oxidation methods for removal of color, chemical oxygen demand (COD), cyanides led to thrust for the development of new promising technologies. In this study, the application of coke breeze for the treatment of wastewater through adsorption has been demonstrated. A pseudo second order reaction kinetics has been observed through batch process adsorption study. Furthermore, adsorption data has found to be best fitted with the Freundlich adsorption isotherm model. Color removal efficiency of 80-90% along with COD removal efficiency of 40-50% was observed within 30 min by 120 g/L dosage of the adsorbent. The removal of phenolic and other organic compounds from coking wastewater has been measured through UV-Vis spectroscopy. The morphological changes of the adsorbent coke breeze have been captured through scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. However, because of the significant abundance in the steel plant, cost effectiveness and applicability of the post-treated coke breeze in sintered plant as fuel, turn it into a suitable adsorbent despite of having much lower specific surface area compared to commercial activated carbon (AC). Therefore, application of the coke breeze turns it into a very promising material and the technique is sustainable towards the coke quenching effluent treatment.