19通道多孔陶瓷膜渗透过程的CFD模拟

根据Darcy定律,建立了多孔陶瓷膜中渗透流动的CFD计算模型,定量描述了纯水在多孔陶瓷膜中的渗流情况。根据CFD模型,采用有限体积法,模拟计算出四种平均孔径陶瓷膜的纯水通量,并与实验值进行了对比,结果吻合较好。采用该模型,定量计算出19通道陶瓷膜中每个通道对整体陶瓷膜渗透通量的贡献,并分析了其中的变化规律,为多孔陶瓷膜的构型优化奠定了基础。     

混凝耦合多孔陶瓷膜净化河水简

Membrane filtration technology combined with coagulation is widely used to purify river water. In this study, micro filtration （MF） and ultrafiltration （UF） ceramic membranes were combined with coagulation to treat local river water located at Xinghua, Jiangsu province, China. The operation parameters, fouling mechanism and pilot-scale tests were investigated. The results show that the pore size of membrane has small effect on the pseudo-steady flux for dead-end filtration, and the increase of flux in MF process is more than that in UF process for cross-flow filtration with the same increase of cross-flow velocity. The membrane pore size has little influence on the water quality. The analysis on membrane fouling mechanism shows that the cake filtrationhas significant in fluence on the pseudo-steady flux and water quality for the membrane with pore size of 50, 200 and 500 nm. For the membrane with pore size of 200 nm and backwashing employed in our pilot study, a constant flux of 150 L-m^-2-h^-1 was reached during stable operation, with the removal efficiency of turbidity, total organic carbon （TOC） and UV254 higher than 99%, 45% and 48%, respectively. The study demonstrates that coagulation-porous ceramic membrane hybrid process is a reliable method for river water purification.     

面向健康产业应用需求的膜技术与膜材料

健康产业发展潜力巨大,其中,医药、医疗和保健行业占有重要地位,但其面临医药资源利用率低、生产工艺污染严重、高端产品依赖进口、质量标准体系不完善等制约因素。将膜分离技术应用于医药、医疗和保健行业,解决发展面临的诸多问题,对于推进我国健康产业发展将发挥重要作用。鉴于国内外尚无针对膜技术应用于健康产业进展的相关文献报道,本文针对面向健康产业应用的膜技术及膜材料进展进行了综述,探讨了健康产业应用对膜材料提出的要求及标准,重点研究了微滤、超滤、反渗透、纳滤、膜生物反应器、渗透汽化、气体分离、人工脏器等膜材料现状,分析了制约其发展的关键问题并提出相关建议,以期为相关部门及行业人员提供参考。     

终端陶瓷膜法海水淡化预处理

采用低能耗的终端过滤方式进行陶瓷膜法海水淡化预处理,比较了"絮凝沉降 陶瓷膜"和"砂滤 陶瓷膜"两种预处理工艺.前者延长了膜再生周期,其陶瓷膜的平均渗透通量是后者的1.6倍,达到220 L/(m2·h),产水回收率大于90%.经陶瓷膜预处理后的产水水质稳定,达到反渗透膜的进水水质要求.结果表明,"絮凝沉降 陶瓷膜"预处理工艺明显优于"砂滤 陶瓷膜"预处理工艺.     

一体式气升陶瓷膜过滤碳酸钙悬浮液的研究

陶瓷膜具有化学稳定性好、机械强度高以及分离精度高等优点,在超细粉体固液分离中的应用越来越广泛。采用一体式气升陶瓷膜过滤装置分离平均粒径为4μm碳酸钙颗粒悬浮液,考察了有无曝气及曝气方式对膜污染控制的影响,发现对膜通道曝气可有效控制跨膜压差的增长率,但增大了进膜的固含量;以跨膜压差增长率结合能耗分析,设计了进料浓度、产水流量和曝气量三因素三水平正交试验,优化后的操作条件为进料浓度20.9 g/L、产水流量20 L/h、进料流量20 L/h、曝气量0.25 m~3/h。连续过滤碳酸钙悬浮液420 min后,可获得浓度为363.9 g/L的浓缩液,运行能耗为0.7 kWh/m~3。研究结果为超细悬浮液的高倍数浓缩提供了数据参考。     

陶瓷膜连续反应器的设计与工程应用

膜反应器是结合膜技术和反应器,将反应和分离两个单元操作耦合成为一个单元过程的系统,可简化流程、节约成本、提高产品质量并减少环境污染。本文就陶瓷膜连续反应器运行过程中存在的膜与反应过程优化、超细颗粒吸附、膜污染等关键问题作了阐述,并以重要的沉淀反应与非均相催化反应为对象,介绍了连续膜反应器的设计及工程应用进展。     

pH敏感型管式陶瓷复合膜的制备

采用硅烷偶联剂KH-570在乙醇溶剂中以盐酸溶液为催化剂进行水解后对管式ZrO2陶瓷膜进行表面修饰,进一步用化学接枝法将丙烯酸单体接枝到改性ZrO2陶瓷膜上,制备pH敏感型陶瓷复合膜.系统考察了不同偶联反应条件对氧化锆陶瓷膜的硅烷化改性效果的影响;研究了丙烯酸单体浓度对pH敏感膜渗透通量及pH开关系数的影响.通过扫描电镜(SEM)、X射线光电子能谱(XPS)、热重(TG)及水通量测定等对改性前后膜结构和pH敏感性能进行分析.结果表明,在以乙醇为溶剂进行硅烷化改性后,成功引入了碳-碳双键,并将丙烯酸成功接枝在陶瓷膜表面;单体浓度对pH敏感的膜通量及pH开关系数有重要的影响;所制备膜显示了良好的pH敏感性能.     

多孔陶瓷膜反应器用于非均相超细纳米催化的研究进展(英文)

Heterogeneous catalysts with ultrafine or nano particle size have currently attracted considerable attentions in the chemical and petrochemical production processes, but their large-scale applications remain challenging because of difficulties associated with their efficient separation from the reaction slurry. A porous ceramic membrane reactor has emerged as a promising method to solve the problem concerning catalysts separation in situ from the reaction mixture and make the production process continuous in heterogeneous catalysis. This article presents a review of the present progress on porous ceramic membrane reactors for heterogeneous catalysis, which covers classification of configurations of porous ceramic membrane reactor, major considerations and some important industrial applications. A special emphasis is paid to major considerations in term of application-oriented ceramic membrane design, optimization of ceramic membrane reactor performance and membrane fouling mechanism. Finally, brief concluding remarks on porous ceramic membrane reactors are given and possible future research interests are also outlined.     

相分离法制备可控大孔-介孔TiO_2陶瓷材料

在酸性条件下,采用溶胶-凝胶技术结合相分离法,制备了结构可控的大孔-介孔二氧化钛材料,并采用X射线衍射(XRD)、低温N2吸附-脱附和扫描电镜(SEM)等表征方法,考察硝酸浓度对样品微结构和大孔形貌的影响。结果表明:随着硝酸浓度的增加,TiO2晶型发生转变,其比表面积和孔容减小;当硝酸浓度达到20%时,出现孔结构坍塌,使材料的比表面积和孔容都急剧减小;随着硝酸浓度的增加,材料内部骨架呈现不同的孔结构,酸浓度为5%时,材料内部呈交联互穿孔结构;当酸浓度为10%时,材料内部呈均一分布的圆孔。     

NaA分子筛合成残余物掺杂制备SiC膜支撑体

选用平均粒径100μm碳化硅为主要原料粉体,NaA分子筛合成废液中提取的粉体(主要成分为NaA分子筛和微量硅铝钠化合物)为烧结助剂,采用挤出法进行生坯成型,最后通过原位烧结技术制备高温气体净化用的管式碳化硅膜支撑体(外径60 mm,内径40 mm,长1 500 mm).研究结果表明,烧结助剂的最佳含量为质量分数3%,随着烧成温度的升高,碳化硅膜支撑体孔隙率逐渐减小,平均孔径也随之增加.当烧成温度达到1 150℃时,膜支撑体平均孔径为30.92μm,气体通量为99.32 m~3/(m~2·h·kPa),抗弯强度达到29.50 MPa,同时也表现出优异的抗热震性能和耐酸腐蚀性能,为高温气体净化碳化硅膜的低成本、绿色化制备以及应用研究提供了理论依据.