Research progress of resource utilization technologies for desulfurization wastewater in coal-fired power plants

Abstract

The low-carbon resource utilization of desulfurization wastewater is the key to promoting zero liquid discharge of wastewater in the coal-fired power industry, realizing economic benefits and environmental protection. Based on the analysis of the water quality characteristics of desulfurization wastewater, this paper summarizes the development process of resource utilization mode and technologies for desulfurization wastewater in coal-fired power plants, systematically expounds the technical categories, technical principles, technical characteristics and applicability of desulfurization wastewater resource utilization technologies, evaluates the application effect and economy of typical application cases and prospects the direction of resource utilization of desulfurization wastewater. The analysis shows that the desulfurization wastewater has experienced three stages: high salt-concentration water resource utilization, low salt-concentration water resource utilization and salt separation resource utilization. The current salt separation resource utilization technology mainly includes chemical precipitation, membrane and thermal evaporation. Relatively speaking, membrane technology is an effective means of low-carbon resource utilization of desulphurization wastewater since extensive water quality adaptability, abundant resource products, lower energy consumption and drug consumption. The feasibility and economics of the zero liquid discharge process route for desulfurization wastewater membrane resource utilization have been analyzed and evaluated, which shows that the membrane technology coupled with nanofiltration and ion exchange electrodialysis has significant advantages in reducing the cost of pretreatment chemicals and system operation cost. However, the selective "ion exchange membrane" is the bottleneck of low-carbon resource utilization and zero liquid discharge of desulfurization wastewater, the development of low-cost, high-efficiency and pollution-resistant membrane materials is the focus of future research.

Keywords

• coal-fired power plant
• desulphurization wastewater
• zero liquid discharge
• salt separation technique
• resource utilization