低脱钙纳滤膜用于非常规饮用水源的达标处理  

Low-calcium-retention nanofiltration membrane for treatment of unconventional drinking water sources

作　　者：贾雨萌 秦英杰[1] 许玉壮 刘一 蔡腾豪 JIA Yumeng;QIN Yingjie;XU Yuzhuang;LIU Yi;CAI Tenghao(School of Chemical Engineering and Technology,Tianjin University,Tianjin 300350,China;PureSea Spring Membrane Technology,Ltd.,Tianjin 300350,China)

机构地区：[1]天津大学化工学院,天津300350 [2]洁海瑞泉膜技术(天津)有限公司,天津300350

出　　处：《膜科学与技术》2022年第1期129-137,共9页Membrane Science and Technology

基　　金：国家重点研发计划项目(0401220004)。

摘　　要：纳滤(NF)可用于处理高硬度、高硫酸根含量的非常规水源,然而硫酸钙结垢导致淡水回收率降低等问题.采用低钙离子脱除纳滤膜(LCNF)可减少硫酸钙结垢.本研究采用LCNF和商用NF对单盐溶液、硬度和硫酸根含量超标的地下水进行了处理对比试验,研究了压力、温度及料液中离子种类和浓度对膜性能的影响.结果表明,在0.6 MPa压力下处理6.5 mmol/LCaCl_(2)溶液、5.5 mmol/L MgSO_(4)溶液,LCNF的脱除率分别为44.89%(Ca^(2+))、99.05%(Mg^(2+)).LCNF对CaCl_(2)的脱除率与传统纳滤膜科氏SR3D-VYV(NF1)、苏伊士DK-2540-F30(NF2)的90.80%和76.73%相比分别降低了45.91%和31.84%.LCNF用于处理某处超标地下水时,对Ca^(2+)、Mg^(2+)、SO_(4)^(2-)的脱除率分别为72.12%、88.68%、99.00%.其对Ca^(2+)的脱除率明显低于NF1、NF2的89.44%、85.78%.用LCNF处理该处地下水时,达标淡水的回收率达到80%时的膜通量仅比初始膜通量降低了4.97%,而NF1、NF2膜通量则降低了52.38%、15.15%.实验中也观察到商用NF在高通量或高淡水回收率下浓缩液出现结垢现象,而LCNF则未观察到结垢现象.本研究表明新型LCNF膜更适合高硬度、高硫酸根地下水的达标处理.Nanofiltration(NF)technology can be used to treat unconventional water source with high hardness and sulfate content.However calcium sulfate scaling leads to problems such as reduction of the permeate water recovery.Low-calcium-rejection nanofiltration membrane(LCNF)can reduce CaSO_(4) scaling by partially allowing Ca^(2+) to pass through.In this study,LCNF membrane module NF3 and conventional NF membrane module NF1 and NF2 were used to treat dilute aqueous solution of single salts and groundwater with hardness and sulfate content exceeding the national standard.The effects of pressure,temperature,ion species and concentration in feed solution on membrane performance were studied.The results showed that the rejection rates of LCNF were 44.89%and 99.05%respectively to 6.5 mmol/L CaCl_(2) solution and 5.5 mmol/L MgSO_(4) solution at feed pressure of 0.6 MPa.The rejection rate of NF1 to calcium chloride was 45.91%and 31.84%lower than that of NF1 and NF2 which was 90.80%and 76.73%respectively.The rejection rate of all NF membrane to magnesium sulfate was basically the same.When LCNF was used to treat groundwater of high hardness and sulfate content,the rejection rates of Ca^(2+)、Mg^(2+)、SO_(4)^(2-) were 72.12%,88.68%,99.00%respectively.The rejection rate of NF3 to Ca^(2+)was significantly lower than that of NF1 and NF2 which was 89.44%and 85.78%respectively,while the rejection rate of Mg^(2+) and SO_(4)^(2-) was basically the same.Meanwhile the permeation flux of NF3 increased by 37.5%compared with that of NF1,which was similar to that of NF2.When the permeate water recovery rate reached 80%,the permeation flux of NF3 membrane was only 4.97%lower than the initial flux,while the permeation flux of NF1 and NF2 membrane was 52.38%and 15.15%lower than the initial flux.It was also observed in the experiment that scaling occurred for the conventional NF membrane when dealing with the concentrated groundwater under high pressure or with high permeate water recovery,while scaling did not occur for LCNF membrane.This stud

关 键 词：低钙脱除率 纳滤 地下水 高硬度 高硫酸根 淡水回收率 

分 类 号：TQ028[化学工程] TU991.264[建筑科学—市政工程]