膜电解关键因素对纳滤浓水钙镁分级结晶控制研究  

Key factors of membrane electrolysis control the ordered crystallization of calcium and magnesium in nanofiltration concentrate

作　　者：王金龙 张浩 陈杰 陈康 陈靖媛 张晗 梁恒[1] 芮旻 WANG Jinlong;ZHANG Hao;CHEN Jie;CHEN Kang;CHEN Jingyuan;ZHANG Han;LIANG Heng;RUI Min(Harbin Institute of Technology,State Key Laboratory of Urban Water Resource and Environment,Harbin 150090,China;Jiangsu Nollet Intelligent Water Equipment Co.,Ltd.,Nantong 22633l,China;Shanghai Municipal Engineering Design Institute(Group)Co.,Ltd.,Shanghai 200092,China)

机构地区：[1]哈尔滨工业大学城市水资源与水环境国家重点实验室,哈尔滨150090 [2]江苏诺莱智慧水务装备有限公司,南通226331 [3]上海市政工程设计研究总院(集团)有限公司,上海200092

出　　处：《给水排水》2024年第6期68-78,共11页Water & Wastewater Engineering

基　　金：国家自然科学基金(52200009);哈尔滨工业大学城市水资源与水环境国家重点实验室开放基金项目(QG202227)。

摘　　要：针对市政纳滤浓水资源化处理过程产物种类复杂的问题,基于膜电解阴极放电极化原理,借助浓水高盐低阻特性,采用膜电解实现浓水的分级结晶,以较低能耗回收CaCO_(3)、Mg(OH)_(2)。研究发现基于阳离子交换膜(Cation exchange membrane,CEM)的电解对钙镁分级结晶的效果最优,在pH为10.5和11.5时可分别实现钙与镁的分离回收。与连续流CEM电解相比,序批式系统能耗较低、产水速率较快,且运行中回收碳酸钙纯度为96.77%,氢氧化镁纯度为81.95%。多周期运行时膜电解功率变化平稳,系统能耗不超过9.2 kW·h/m^(3)。另外,阳离子交换膜的阴、阳极侧的污染成因不同,膜的阴极侧污染多是阴室内生成的钙镁沉淀附着物,阳极侧污染由阳室中无机物和有机物共同作用形成。结果表明,膜电解系统可成为纳滤浓水钙镁分级结晶回收的策略之一。To address the complexity of the product types in the municipal nanofiltration(NF)concentrate treatment,CaCO_(3)and Mg(OH)_(2)are recovered with low energy consumption with the help of high salt and low resistance characteristics of NF concentrate based on the principle of cathode discharge polarization in membrane electrolysis.The cation exchange membrane(CEM)electrolysis was optimal for the ordered crystallization of calcium and magnesium,and the separation and recovery of calcium and magnesium could be achieved at pH 10.5 and 11.5,respectively.Compared with continuous-flow CEM electrolysis,the sequential batch system consumed less energy,produces water faster,and recovers calcium carbonate with a purity of 96.77%and magnesium hydroxide with a purity of 81.95%.Membrane electrolysis power was changed slightly during multi-cycle operation with total energy consumption lower than 9.2 kWh/m^(3).In addition,the membrane fouling on the cathode and anode sides showed different,and the cathode side was due to the adhesion of calcium and magnesium precipitates generated in the cathode chamber,and the fouling on the anode side was the result of the combination of inorganic and organic substances in the anode chamber.The results showed that the membrane electrolysis system can be one of the strategies for the recovery of calcium and magnesium in NF concentrate by ordered crystallization.

关 键 词：纳滤浓水 资源回收 离子交换膜电解 膜污染 

分 类 号：TU992[建筑科学—市政工程]