The significance of resource recycling for coking wastewater treatment: based on environmental and economic life cycle assessment

The sustainability of the coking industry is supported by reasonable production profit and environmental quality requirements. The traditional measures substantially increased the related costs for enterprises to reach standards. This paper aims to develop a comprehensive cost combined environmental impact assessment method that is necessary for the analysis of wastewater treatment systems. Typical three coking wastewater treatment processes in China were evaluated. Results showed that eutrophication dominantly contributed to the overall environmental effect. Improving effluent quality could significantly reduce the total environmental impact. In terms of an economic perspective, the price of raw materials was the main factor that affected the operating cost of comprehensive treatment. Based on subsystem analysis, the pretreatment stage accounted for the majority of environmental and cost burdens, respectively reaching 64%-78% and 64%-86%. Optimizing the pretreatment process by enhancing the efficiency of high concentration raw material recovery and substituting toxic raw materials for extractant could reduce the environmental impact and economic cost by 43.8% and 57%, respectively, which was an effective way to improve the potential performance of coking wastewater treatment plants (WWTPs).