机械式蒸汽再压缩技术浓缩脱硫废水中试研究  

Pilot Study on the Concentration of Desulfurization Wastewater by Mechanical Vapor Recompression Technology

作　　者：林廷坤 冯永新 赵宁 谢志文 LIN Tingkun;FENG Yongxin;ZHAO Ning;XIE Zhiweng(China Southern Power Grid Technology Co.,Ltd;Electric Power Research Institute of Guangdong Power Grid Corporation:Guangzhou 510080,China)

机构地区：[1]南方电网电力科技股份有限公司 [2]广东电网有限责任公司电力科学研究院,广东广州510080

出　　处：《水处理技术》2022年第8期111-115,119,共6页Technology of Water Treatment

基　　金：中国南方电网有限责任公司科技项目:高耗水企业废水资源化及零排放关键技术研究与集成应用(GDKJXM20183546)。

摘　　要：以某燃煤电厂石灰石-石膏湿法脱硫系统排放的高盐脱硫废水为对象,采用机械式蒸汽再压缩技术(MVR)进行废水浓缩中试实验。对于浓缩液,随着浓缩倍率增加,pH迅速降低,Cl^(-)浓度呈线性增长趋势,平均富集度达到85.2%,高浓缩阶段(浓缩倍率5~7倍)Larson指数在5900以上,说明浓缩液具有很强的氯腐蚀强度;而受CaSO_(4)溶解平衡影响,高浓缩阶段的SO_(4)^(2-)质量浓度维持在5300 mg/L左右,不再提高,Ca^(2+)的平均富集度也仅为46.6%。对于蒸馏水,水质达到循环冷却水水质标准,可以作为循环冷却水回用。另外本系统的电耗仅为46.5 kWh/m^(3),低于四效蒸发浓缩等工艺,可以有效降低运行成本,适用于大规模脱硫废水处理系统。Taking the high-salt desulfurization wastewater discharged from the limestone-gypsum wet desulfurization system of a coal-fired power plant as the object,the mechanical vapor recompression technology(MVR)was used to conduct a pilot test of wastewater concentration.For the concentrated solution,as the concentration rate increased,the pH decreased rapidly and the concentration of Cl^(-)showed a linear growth,and the average enrichment factor was 85.2%.Further,the Larson index in the high concentration stage(concentration rate between 5~7 times)was above 5900,indicating the concentrated solution had a strong chlorine corrosion strength.Affected by the equilibrium of the CaSO_(4) dissolution,the SO_(4)^(2-)concentration in the high concentration stage was maintained at 5300 mg/L,with no longer increase,and the average concentration of Ca^(2+)was only 46.6%.For distilled water,the water quality reached the circulating cooling water quality standard and could be reused as circulating cooling water.In addition,the power consumption of this system was only 46.5 kWh/m^(3),which was lower than that of the four-effect evaporation and other processes.It can effectively reduce operating costs and is suitable for large-scale desulfurization wastewater treatment systems.

关 键 词：蒸汽再压缩 脱硫废水 浓缩液 富集度 腐蚀 蒸馏水 

分 类 号：X773[环境科学与工程—环境工程]