基于“零排放”工艺的某火力发电厂高盐废水处理方案探究

The Discuss of Projects about Zero Liquid Discharge System for Treating High-Salinity Wastewater from Thermal Power Plant

以宁夏某一2×330 MW的火力发电厂为例,在其工业生产过程中需要大量的水,其中循环冷却水量高达150m^3/h。为了实现废水的"零排放"和回收利用,必须对火电厂产生的高含盐循环冷却废水进行处理,现提出了"预处理+脱盐浓缩+蒸发结晶"的组合工艺。在此工艺的基础之上,设计了4种不同的方案,分析结果显示4种方案均可以达到"零排放"的要求,并且最终的淡水回收率达到96%以上。通过技术和经济的分析结果表明:方案三,"石灰碳酸钠软化+反渗透膜浓缩+EDR浓缩+蒸发结晶"适用于本工程的实际情况。

Taking the 2×330MW.Thermal Power Plant in Ningxia as an example, in the industrial process, it requires a large amount of water, in which about 150 m^3/h circulating cooling water is required. In order to achieve ＂Zero Liquid Discharge＂ and recycling, it was proposed a combined process of ＂Pretreatment ＋ Desalting concentration ＋ Evaporative Crystallization＂ to treat the sewage. Based on the process, we designed four projects and the results implied that all of the projeets were able to satisfy the demand, fresh water recovery percent reached 96%. Through the analysis of technology and economy, the results showed that the project no.3, ＂Lime-Natronite Softening ＋ Reverse Osmosis Membrane Concentration ＋ EDR Concentration ＋ Evaporative Crystallization＂ was suitable for the actual situation of this case.