燃煤电厂烟气脱硫废水处理方法与技术进展

摘要

燃煤电厂石灰石-石膏湿法烟气脱硫塔,在运行过程中会产生一定量高含盐量、高悬浮物、高硬度的脱硫废水.化学沉淀法是目前使用最广的脱硫废水处理方法,但存在着加药量大、污泥产生量大、出水含盐量高等缺点.综述了湿法烟气脱硫废水的产生过程、杂质来源、水质特性,介绍了化学沉淀法等传统处理工艺和烟道蒸发、蒸发结晶、炉渣废热综合利用等几种零排放技术的处理思路、流程、优势以及存在的问题.结合国内外高盐废水处理技术的研究进展,介绍了膜分离、正渗透等资源化技术在脱硫废水中的应用情况.最后结合国家废水处理政策与脱硫废水处理现状、技术进展,对烟气脱硫废水处理的发展方向进行展望.%Wet lime stone-gypsum flue gas desulfurization (FGD) absorbing tower will produce a certain amount of produce desulfurization wastewater in the running process,which contains high salinity,excess suspended solids,and high hardness.Currently,chemical precipitation method is the most widely used desulfurization wastewater treatment method.However,it suffers from many drawbacks such as a large amount of reagent dosage,and generation of sludge,and high concentration of salts in effluent.In this paper,the generation process,the sources of impurities,and the characteristics of water quality of the wet five gas desulfurization wastewater were reviewed.In addition,the traditional chemical precipitation technology and the zero liquid discharge technologies including flue gas evaporation technology,evaporation crystallization technology,and comprehensive utilization of slag waste heat,were also introduced.First,the technical processing ideas,processes,advantages and existing problems of these technologies were summarized.Then,the application of resource utilization technologies in FGD wastewater treatment,such as membrane separation and forward osmosis (FO),were also reviewed by summarizing research progresses of high salinity wastewater treatment technologies.Finally,the future direction of FGD wastewater treatment was proposed based on the analysis of national policies of China's wastewater treatment,current situation and technology progress.