地质聚合物基无机膜去除水中钙、镁离子的研究∗

摘要

以偏高岭土为前驱体材料,以改性水玻璃为碱激发剂,以去离子水为造孔剂,按照设计配比(n(SiO2)(Na2O)＝1．3,n(Na2O)(Al2O3)＝0．8,n(SiO2)(Al2O3)＝2．96,n(H2O)(Na2O)＝10~24)混合均匀后制得地质聚合物浆料,将浆料注模后于60℃条件下养护1 d 后脱模,并于常温下养护7 d 后得地质聚合物无机膜.利用SEM(扫描电镜)、比表面积与孔隙度测试仪、全自动孔径分析仪、电子万能试验机以及膜装置测试水通量等手段对膜材料进行表征,最终获得用于水处理无机膜的最优 H2 O/Na2 O 比为19.结果显示,该配比下制备的地质聚合物无机膜具有大的孔体积和比表面积,具有均匀的孔径分布、较高的气孔率和较好的力学强度,能够满足水处理的基本要求.将该地质聚合物无机膜应用于自来水中 Ca2＋、Mg2＋的去除实验,结果表明钙镁离子截留率高,具有很好的实用价值.%This study used metakaolin as raw material,used modified industrial water glass as alkali activator, and used deionized water as foaming agent.The geopolymer slurry was prepared by mixing evenly according to the formula molar ratio (n(SiO2 )(Na2 O)=1.3,n(Na2 O)(Al2 O3 )=0.8,n(SiO2 )(Al2 O3 )=2.96, n(H2 O)(Na2 O)=10-24).After the slurry was cast into mould,and it was cured under the condition of 60 ℃and demoulded after 1 d,and then cured at room temperature for 7 days so that we could get the geopolymer-based inorganic membrane.Using XRD(X- ray diffraction),SEM (scanning electron microscopy),specific sur-face area and porosity testing apparatus,automatic pore size analyzer,compressive strength and water flux test,it is found that the inorganic membrane has large porous volume and surface area structure,uniform pore size distribution,high porosity and good mechanical strength,which are good at removal of Ca2+ and Mg2+ in tap water.The experiment results showed that inorganic membrane has a high rej ection rate,and it has good practical significance.