新型真空膜渗透结晶工艺初探  

Preliminary study on a novel vacuum membrane percrystallization process

作　　者：孟芸翊 李魁岭 俞灵 张勇[1,2,3] 刘泓锌 王军 MENG Yunyi;LI Kuiling;YU Ling;ZHANG Yong;LIU Hongxin;WANG Jun(State Key Laboratory of Environmental Aquatic Chemistry,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;National Engineering Laboratory for Industrial Wastewater Treatment,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院生态环境研究中心,环境水质学国家重点实验室,北京100085 [2]中国科学院生态环境研究中心,高浓度难降解有机废水处理技术国家工程实验室,北京100085 [3]中国科学院大学,北京100049

出　　处：《环境工程学报》2021年第7期2314-2321,共8页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(51978651);中国科学院饮用水科学与技术重点实验室专项(20Z07KLDWST);国家能源集团科技创新项目(GJNY-18-62)。

摘　　要：真空膜渗透结晶工艺(vacuum membrane percrystallization,VMPC)是一种新型膜结晶工艺,可同步实现溶质的结晶及其与溶剂的分离回收。以NaCl溶液为目标物系,对VMPC过程的原理进行了分析,初步考察了进料液温度、浓度和操作压力对该工艺产能的影响。结果表明:VMPC过程是膜渗透和真空压差闪蒸结晶的协同作用的过程,随进料液温度的升高,结晶盐通量和水通量均增大;随进料液浓度的升高,结晶盐通量增大,水通量降低;而操作压力对工艺产能影响较小,但对生成晶体的形貌影响显著;当进料液温度为34℃,进料质量分数为25%,操作压力为0.5 kPa时,可获得高达8.04 kg·(m^(2)·h)^(−1)的盐通量和30 L·(m^(2)·h)^(−1)的水通量,远高于现有太阳能驱动膜结晶技术的产能。针对现有膜滤浓缩液类高浓盐水结晶工艺流程复杂、能耗高、效率和产能低的问题,VMPC工艺为新型高效处置技术的开发及应用提供了可行的解决方案。VMPC process is a new kind of membrane crystallization process.It can realize the simultaneous separation and recovery of solute crystallization and solvent in a single step.In this study,the principle of VPMC process was analyzed and the effects of different temperature and concentration of feed solution,and vacuum operating pressure on the productivity were investigated preliminarily by taking a NaCl solution as the target system.The results showed that VMPC was a co-development process of membrane permeation and vacuum pressure differential flash crystallization.With the increase of feed liquid temperature,water flux and crystallized NaCl flux increased.With the increase of feed liquid concentration,the crystallized NaCl flux increased,while the water flux decreased.In addition,the operating pressure had a significant effect on the morphology of the NaCl crystals rather than crystallization productivity.When the temperature of the feed liquid was 34℃,the mass fraction was 25%,and the operating pressure was 0.5 kPa,a NaCl flux up to 8.04 kg·(m^(2)·h)^(−1) and water flux up to 30 L·(m^(2)·h)^(−1) were obtained through experiments,which was far higher than the capacity of existing solar-driven evaporator crystallization technologies.This work developed a novel process to address the challenges in terms of complex process flow,high energy consumption,low efficiency and productivity during existing crystallization process of membrane filtration concentrate,thereby provide an important solution for further development and application of efficient treatment technologies of high salinity wastewater.

关 键 词：真空膜渗透结晶 膜结晶 晶体成核 高盐废水 零排放 

分 类 号：X703[环境科学与工程—环境工程]