Experimental study on the treatment of desulfurization wastewater from coal-fired power plant by spray evaporation

• DOI: 10.1007/s11356-022-21859-7
• Publication Date: 2022-07-25T01:02:17Z
• Authors: Zongkang Sun; Ning Zhao; Yongxin Feng; Fengjun Liu; Chenjian Cai; Guangmin Che; Yaping Zhang; Hao Wu; Linjun Yang
• Keywords: Particle (ecology)

Abstract The desulfurization wastewater in coal-fired power plants is difficult to treat due to its high salt concentration and complex composition. In this study, a pilot-scale evaporation tower system was built to treat the desulfurization wastewater by spray evaporation. The distribution characteristics of Cl- in wastewater evaporation process, the characteristics of solid evaporation products from desulfurization wastewater and the influence on the characteristics and removal effect of particulate matters in flue gas were investigated. The results show that the increase of salt content in desulfurization wastewater increased the mass concentrations of Cl- in the gas phase, outlet solid phase and bottom solid phase, but the proportions of it in three phases remained almost unchanged. The increase of flue gas temperature can improve the content of Cl- in the gas phase, while the increase of wastewater pH inhibited the formation of gaseous HCl. The solid evaporation products from desulfurization wastewater had prismatic crystal structure, which mainly included the sulfate and chloride salts, and the main elements in them were O, Na, Mg, S, Cl, K and Ca. Besides, the particle size of bottom solid phase was larger than that of outlet solid phase. For the particulate matters in flue gas, the spray evaporation of desulfurization wastewater can reduce the particle concentration, promote the particle agglomeration, reduce the number concentration of fine particles and improve the removal effect of PM10.