An optimized design for zero liquid discharge from coal chemical industry: A case study in China

Zero liquid discharge (ZLD) is an efficient solution for the issue of global water scarcity. To improve energy efficiency, existing units should be optimized treat coal chemical industry (CCI) wastewater. This study introduced a new design and optimization model for a CCI wastewater treatment approach that may achieve ZLD, as well as minimizing wastewater treatment costs. The model, considered treatment chemicals, flowrate, salinity, and operating pressure. Using different input conditions, the use of the ZLD system for CCI wastewater treatment was illustrated, and the respective mass balance diagram was developed. In addition, the economic cost of different units for each scenario involved in treating CCI wastewater was calculated. The levelized cost of water (LCOW) reached 1.325 $/m(3) when the salinity of input is 3000 mg/L. Furthermore, an environmental impact analysis was conducted on chemical, electricity, steam and solid waste for each technology in the ZLD system for treating CCI wastewater. This study presents an effective design and optimization process that could significantly screen CCI wastewater for the application of a ZLD process with the goal of reducing environmental impacts and minimizing the cost of wastewater treatment.

Automated summary

This study presents a new design and optimization model for achieving Zero Liquid Discharge (ZLD) for coal chemical industry wastewater, aiming to reduce environmental impacts and minimize wastewater treatment costs.