燃煤电厂湿法脱硫废水零排放处理技术进展

DEVELOPMENT OF ZERO LIQUID DISCHARGE TECHNOLOGIES FOR DESULFURIZATION WASTEWATER FROM COAL-FIRED POWER PLANT

湿法脱硫技术广泛应用于燃煤电厂烟气脱硫中。在运行中会产生含有高盐和重金属的脱硫废水,目前脱硫废水主要采用化学沉淀法处理,但该工艺存在药剂投加量大、污泥产生量多、以及部分指标达标困难等缺点。而且化学沉淀法处理后的出水含盐量高,直接排放容易引起二次污染。因此,脱硫废水的零排放处理引起越来越多的重视。在对已有相关文献和相关报道进行了全面分析和总结的基础上,重点介绍了脱硫废水零排放处理技术分类、原理和研究应用现状。最后,对脱硫废水零排放处理技术的研究和发展方向进行展望。

Wet flue gas desulfurization（ WFGD） is the most popular technology for sulfur dioxide reduction from the exhaust flue gas of fossil fuel thermoelectric power plants. The WFGD wastewater is characterized with high concentration of salts and various heavy metals. To date,the wastewater is mostly treated by chemical precipitation. Chemical precipitation methods,however,may have significant drawbacks such as high reagent consumption,excess solid waste production and often failure to comply with the respective regulatory discharge limits. In addition,the treated wastewater by chemical precipitation often contains high concentration of salts,which may constitute a secondary pollution. As an alternative solution for treating the WFGD wastewater, zero liquid discharge（ ZLD） technologies have received greater attentions in recent years. The classifications,principles and current statuses of different ZLD technologies for the WFGD wastewater application were thoroughly reviewed based on a large body of published literatures. Finally,the future direction of research and development on the ZLD technologies for the WFGD wastewater were proposed.