机械蒸汽再压缩技术处理反渗透浓水的中试研究  

Pilot Study on Mechanical Vapor Recompression Technology for Treatment of Concentrated Water from Reverse Osmosis Process

作　　者：张金鸿[1] 侯霙[1] 李海芳[1] 唐运平[1] 

机构地区：[1]天津市环境保护科学研究院,天津300191

出　　处：《中国给水排水》2011年第11期1-4,共4页China Water & Wastewater

基　　金：国家水体污染控制与治理科技重大专项(2008ZX07314-001)

摘　　要：近年来,反渗透(RO)在污水厂二级出水深度处理中的应用越来越多。然而,RO浓水的含盐量较高、有机物难于降解,采用常规方法处理时出水水质难于达到排放标准。采用机械蒸汽再压缩技术(MVR)对某污水厂的反渗透浓水进行了6倍浓缩的中试,其出水COD≤50 mg/L、NH3-N≤10 mg/L,可以达到《城市污水再生利用城市杂用水水质》(GB/T 18920—2002)的要求;COD、TDS、Mg2+和色度等指标的浓缩倍数与体系的浓缩倍数基本一致,而浓缩水中的TP、SiO2、TN、NH3-N浓度却低于原水的,这主要是由于磷酸盐、硅酸盐的沉淀和氨气逸出所致。另外,钙盐等的沉淀作用还造成浓缩水中SS浓度的增加。由此可见,利用MVR处理反渗透浓水在技术上是可行的,但是需要增加沉淀物的预处理和排出气体的收集处理装置。Recently, the application of reverse osmosis （RO） in advanced treatment of effluent form WWTP becomes very popular. However, due to high salinity and refractory organic compounds in concentrated water of RO, the effluent treated by traditional processes can not meet the discharge standard. A pilot experiment at a concentration factor of 6 was conducted to treat concentrated water from re- verse osmosis （RO） process in a sewage treatment plant using mechanical vapor recompression （MVR） technology. COD and NH3 - N in the effluent from MVR process are equal to or less than 50 mg/L and 10 mg/L, meeting the Reuse of Urban Recycling Water--Water Quality Standard for Urban Miscellaneous Water Consumption （GB/T 18920 -2002）. The concentration factors of COD, TDS, Mg2＋ and color in concentrated water of MVR are similar to those in concentrated water of RO. However, the concentration factors of TP, SiO2, TN and NH3 - N are lower than those in concentrated water of RO due to escape of ammonia and precipitation of phosphate and silicate. In addition, precipitation of calcium salt causes in- crease of SS in concentrated water of MVR. The experiment shows that MVR technology is feasible for treatment the concentrated water of RO with consideration of pre-treatment of precipitates and post-treat-ment of escaped gas.

关 键 词：反渗透 浓水 机械蒸汽再压缩技术 浓缩倍数 

分 类 号：X703[环境科学与工程—环境工程]