萃取剂P507对反渗透处理稀土冶炼废水脱盐性能的影响  

Effect of Extractant P507 on Desalination of Rare Earth Smelting Wastewater by Reverse Osmosis

作　　者：桂双林[1] 麦兆环 闫冰 易其臻 付嘉琦[1] 吴九九[1] GUI Shuang-lin;MAI Zhao-huan;YAN Bing;YI Qi-zhen;Fu Jia-qi;WU Jiu-jiu(Institute of Energy Research,Jiangxi Academy of Sciences,Nanchang 330096,China)

机构地区：[1]江西省科学院能源研究所,江西西南昌330096

出　　处：《稀土》2022年第2期82-90,共9页Chinese Rare Earths

基　　金：国家自然科学基金项目(21567009);江西省重点研发计划项目(20212BBG71001)。

摘　　要：稀土湿法冶金生产过程中产生大量NH_(4)^(+)-N废水,不仅含有高盐(主要为NH_(4)Cl),还有P507及其化合物等组成的有机污染物等。研究了反渗透膜对稀土冶炼废水中NH_(4)Cl的截留率和渗透性能,其中RO膜对5 g/L的NH_(4)Cl溶液的平均截留率为96.23%,产水氨氮浓度低于50 mg/L,基本能满足《稀土工业污染物排放标准》(GB 26451—2011)要求。通过向模拟稀土冶炼废水(NH_(4)Cl溶液)中添加萃取剂P507模拟稀土冶炼废水中的有机污染物,研究了NH_(4)Cl和P507共混条件下P507含量对反渗透膜脱盐性能的影响,结果表明,较低浓度的P507(≤30 mg/L)对反渗透膜的脱盐效率和渗透通量影响较小。反渗透膜处理NH_(4)Cl+P507混合溶液,膜表面呈现P507有机污染和NH_(4)Cl盐结晶共存的膜污染现象,结果表明,膜面污染物的P含量随着溶液中P507浓度的增加而不断增加,且膜污染随着P507浓度的升高而越来越严重。A large amount of wastewater is produced in the extraction and separation process of rare earth hydrometallurgy with P507 as extractant and ammonia as saponifier.The rare earth smelting wastewater contains not only high salt of NH_(4)Cl,but also organic pollutants such as P507 and its compounds.The rejection and permeability of RO membrane for NH_(4)Cl solution in rare earth smelting wastewater were studied.The average rejection of RO membrane for the concentration of 5 g/L NH_(4)Cl solution was 96.23%,and the concentration of ammonia nitrogen in permeate was lower than 50 mg/L,which can met the emission standards of pollutants from rare earths industry(GB 26451—2011).By adding extractant P507 into NH_(4)Cl solution to simulate organic pollutants in rare earth smelting wastewater,the effect of concentration of P507 on desalination performance of RO membrane to the mixed solution of NH_(4)Cl and P507 was studied.The results showed that lower concentration of P507(≤30 mg/L)had less effect on desalination efficiency and permeate flux of RO membrane.When the mixed solution of NH_(4)Cl and P507 was treated by RO membrane,the membrane surface was showed the coexistence of organic pollution of P507 and salt crystallization of NH_(4)Cl.The results showed that the amount of phosphorus on the membrane surface increased with the increase of concentration of P507 in the mixed solution,and the membrane fouling became more and more serious with the increase of P507 concentration.

关 键 词：萃取剂P507 稀土冶炼 反渗透 脱盐 废水处理 有机物 

分 类 号：X703[环境科学与工程—环境工程]