摘要：

在分析脱硫废水水质特点，以及调研排污许可证中脱硫废水去向和污染物排放执行标准的基础上，论述了脱硫废水达标处理、厂内回用和零排放的技术路线。排污许可证基本不允许脱硫废水外排，并对脱硫废水车间排放口水质进行了严格限定。约80.0%电厂的污染物因子和限值按《火电厂石灰石-石膏湿法脱硫废水水质控制指标》（DL/T 997—2006）执行，部分电厂增加了氨氮污染物因子控制指标、下调了氟化物和COD限值。脱硫废水达标处理，一类污染物重金属主要采用化学沉淀法去除，二类污染物氟化物采用复合盐沉淀技术去除，曝气法和次氯酸钠氧化法相组合的工艺可同步去除脱硫废水中的COD和氨氮。脱硫废水厂内回用方式包括湿除渣和干灰调湿，其中湿除渣系统应主要关注设备腐蚀问题，干灰调湿主要考虑气候以及对周围环境的二次污染问题。脱硫废水零排放采用结晶工艺时需考虑盐的处置以及需通过工艺优化避免产生二次污染物；目前旁路烟气蒸发工艺系统简单、无固废处置问题，是当前脱硫废水固化的主流工艺。

关键词: 脱硫废水, 排污许可, 一类污染物, 二类污染物, 零排放

Abstract:

On the basis of analyzing the water quality characteristics of desulfurization wastewater，as well as the direction of desulfurization wastewater and the discharge standards of pollutants in the sewage permit，the technical route of standard treatment，reuse and zero discharge of desulfurization wastewater were discussed. Almost all of the discharge permit basically did not allow the desulfurization wastewater discharge to external environment，and the quality of desulphurization wastewater at the discharge port of wastewater workshop was strictly limited. The pollutant factors and limits of about 80.0% of power plants were implemented according to Discharge Standard of Wastewater from Limestone-Gypsum Flue Gas Desulfurization System in Fossil Fuel Power Plant （DL/T 997—2006）. Some power plants had added the control indexes of ammonia nitrogen and lowered the limits of fluoride and COD. In the treatment of desulfurization wastewater to reach the standard，heavy metals of class Ⅰ pollutants were mainly removed by chemical precipitation method，fluoride of class Ⅱ pollutants was mainly removed by compound salt precipitation technology，and the combined process of aeration and sodium hypochlorite oxidation could simultaneously remove COD and ammonia nitrogen in desulfurization wastewater. The reuse methods of desulphurization wastewater plant included wet slagging and dry ash humidification. The wet slagging system should mainly focus on equipment corrosion，and the dry ash mixed with wet should mainly consider the climate and the secondary pollution to the surrounding environment. The treatment of salt should be considered in the zero discharge of desulphurization wastewater by crystallization process，and the secondary pollutants should be avoided through process optimization. At present，the bypass flue gas evaporation process system was simple and had no solid waste disposal，which was the main curing process of desulphurization wastewater.

Key words: desulfurization wastewater, discharge permit, first class pollutants, second class pollutants, zero discharge

中图分类号: 

• X703