微滤过程阻力分析及过滤速率

以膜分离基本理论为基础，依据实验结果，研究微滤过程中微粒在膜材料上的吸附和沉积及其对膜透过液流动的影响，建立了吸附阻力和沉积层阻力随时间变化的关系式，就各项阻力对膜分离过程的影响情况进行了分析，并提出了减小这些阻力的途径。在分析膜分离阻力基础上，本文提出了计算微滤膜通量的数学模型，计算结果的平均偏差为５．９％，明显优于同类模型。     

膜系统在生物技术中应用的研究进展

膜系统以其独特的构型和优越的性能而广泛应用于生化反应、物质纯化以及分子、乳剂、微粒的回收、生产中。膜系统利用膜的高选择性、单位体积的高接触面积及其对两相混合或接触水平调控的优势在生物技术中占有重要地位。本文主要论述了各种薄膜的应用研究,包括已经广泛使用的超滤和微滤、新出现的膜生物反应器、膜色谱以及用于制备乳剂和微粒的膜接触器等,并对上述膜过程在膜材料、模型设计、操作参数及在生物技术领域的应用等方面进行了深入研究。     

混凝对微滤膜处理阴极电泳漆废水的影响

采用直接微滤和混凝-微滤两种工艺对阴极电泳漆废水进行处理.结果表明:混凝预处理减轻了膜污染,提高了膜的渗透通量;当膜面流速为4m/s,跨膜压差为0.10MPa,温度为30℃时,稳定通量从直接微滤的47.8L/(m2·h)提高到264.2L/(m2·h),远高于超滤膜的通量.与原水直接微滤相比,混凝-微滤组合工艺改善了出...     

关于中药水提液的粘度特征及其与膜通量的相关性初步研究

研究中药水提液的粘度对无机陶瓷膜微滤中药水提液膜通量的影响及中药水提液在微滤前后粘度变化规律。制备约200种中药（单味及复方）水提液为实验体系,在温度、压力、膜面流速恒定的条件下分别过0．2μmZrO2无机陶瓷膜,测定不同中药水提液的膜稳定通量及微滤前原液、微滤后渗透液、截留液的粘度,并用SPSS对它们的相关性进行分析。结果表明中药水提液的粘度与膜稳定通量有很大的相关性,微滤后渗透液的粘度减小且不同水提液粘度差异性变小,截留液粘度增大、且截留液粘度、粘度变化率与原液粘度呈高度显著线形相关。粘度是影响无机陶瓷膜微滤中药水提液膜通量的关键因素,在中药膜污染的防治过程中可通过提取路线的设计或对药液进行预处理降低药液的粘度从而提高膜通量,减少膜污染。     

旋转流强化管式膜微滤的研究评述

浓差极化和膜污染是阻碍微滤广泛应用的关键难题 ,在认识理解颗粒迁移沉积和过滤速率下降的基础上 ,本文对旋转流管式膜微滤进行了一定的探讨分析。     

颗粒粒径和膜孔径对陶瓷膜微滤微米级颗粒悬浮液的影响

通过测定颗粒悬浮液通过陶瓷微滤膜时的参透通量及污染阻力,确定了陶瓷膜处理微米级颗粒悬浮液时,颗粒粒径和膜孔径对微滤过程的影响和膜污染机理,获得了微米级颗粒悬浮液微滤过程中膜孔径的选择方法。     

Mg（ClO4）2填充聚丙烯晴微滤膜的制备及性能研究

以高氯酸镁(Mg(ClO4)2)为添加剂,采用浸没沉淀相转化法制备了聚丙烯晴(PAN)微滤平板膜。考察了Mg(ClO4)2含量对PAN微滤平板膜纯水通量、膜污染速率、孔隙率、接触角和膜表面形态的影响;并根据相关结论探讨了PAN微滤平板膜抗膜污染主要物质SMP的特性试验。结果表明,PAN微滤平板膜中添加Mg(ClO4)2可改变成膜性能,当Mg(ClO4)2的质量分数为1.5%时,PAN微滤平板膜的成膜性能最优,抵抗强疏水性有机物组分污染的能力增强。     

面向应用过程的陶瓷膜设计方法

无机陶瓷膜以其优良的材料性能获得了广泛的应用。由于膜品种的定型化 ,使膜应用研究受到一定的限制。面向应用过程来设计最优性能陶瓷膜将会是一个重要的发展方向。在提出面向应用过程的陶瓷膜设计基本研究框架基础上 ,以颗粒体系为对象 ,建立起包含膜结构参数的微滤模型 ,考察膜孔径、厚度、孔隙率等结构参数对微滤性能的影响 ,从而从理论上建立颗粒体系微滤过程中最优膜的选择方法     

动态Monte Carlo模拟蛋白质与微滤膜相互作用及其对微滤过程影响

构建了二维晶格蛋白质-微滤膜疏水相互作用模型，采用动态Monte Carlo方法模拟了微滤膜污染过程及其受膜孔径、蛋白质浓度和蛋白质结构特性等因素的影响。模拟结果显示：微滤过程中膜通量的变化呈现快速下降、缓慢下降和平台期3个阶段。小孔径微滤膜的滤阻从以膜孔阻力为主转变为以饼层阻力为主;而大孔径微滤膜的滤阻则以膜孔阻力为主。提高蛋白质浓度会强化滤阻从膜孔阻力向饼层阻力的转变。在微滤过程中，蛋白质会因疏水相互作用在膜孔内发生构象转换，进而发生不可逆吸附并形成多层堆积，导致膜污染和通量下降，提高蛋白质的构象稳定性可以显著降低其对微滤膜的污染。分子模拟结果与文献报道的实验结果和理论模型相符，所提供的微观信息对于微滤过程优化和微滤膜设计具有参考作用。     

具有旋转横流的管式膜微滤的渗透通量及环隙压力分布

用自行研制的计算机控制的在线管式膜器环隙压力测试系统实测分析了不同入口压力、不同悬浮液浓度和不同膜器环隙大小下的旋转横流膜微滤渗透通量大小及环隙压力分布规律,与一般横流膜微滤的环隙压力分布及渗透通量大小进行了对比,为进一步研究膜微滤强化机理、探讨减少或解决浓差极化和膜污染的方法提供了实测依据.     

Fuzzy modeling and hybrid genetic algorithm optimization of virus removal from water using microfiltration membrane

Membranes are finding increasing applications in disinfection processes including virus removal from water for municipal effluent reuse. The capability of virus removal from water by microfiltration membranes has previously been demonstrated. In this study, the capability of fuzzy logic for modeling and simulation of dead-end microfiltration process for removal of IBR and FMD viruses from water was elucidated. The main parameters indicating membrane performance i.e. flux and rejection were experimentally obtained under different conditions and compared with theoretically calculated flux and rejection using fuzzy inference system. The genetic algorithm which is an efficient and systematic method was employed in the design of fuzzy model for optimization of the poorly understood, irregular and complex membership function with improved performance. Hybrid genetic algorithm was used for optimizing the parameters that are located at the Gaussian membership functions in the premise and consequent of each rule.The results indicated that fuzzy inference system predicts the key parameters i.e. flux and rejection for different operating conditions with an acceptable error. In other words FIS is able to apply for modeling the microfiltration membrane which is mathematically difficult or in many cases an unpredictable process.     

重组汉逊酵母表达的HBsAg纯化工艺中内毒素的去除效果

目的分析重组汉逊酵母表达的乙型肝炎表面抗原(HBsAg)各纯化工序样品中内毒素的去除效果。方法采用鲎试剂法检测重组汉逊酵母表达的HBsAg小量工艺探索、中量工艺验证、中试纯化工艺中破碎细胞、微滤、超滤、硅胶吸附、层析、除菌过滤各工序样品的内毒素含量,计算内毒素去除率,分析各纯化工序与内毒素去除率的关系,并以重组酿酒酵母表达HBsAg各纯化工序中样品作为对照。结果重组汉逊酵母表达的HBsAg纯化过程中内毒素含量由细胞破碎样品的241 EU/ml以上降至除菌过滤样品的1.0 EU/ml以下。微滤和超滤样品内毒素去除率平均可达56%和86%,占总体纯化工艺中内毒素去除率的90%以上。结论重组汉逊酵母表达HBsAg纯化工序微滤、超滤和疏水层析均可有效去除内毒素,以超滤去除内毒素效果最明显,为重组汉逊酵母纯化工艺去除内毒素的研究提供了技术参数和实验依据。     

A Macrokinetic Modeling of Membrane Microfiltration Processes

Abstract

Membrane microfiltration techniques have been developed and utilized mostly in the fields of gas purification and aerosol filtration. They were recently applied to medical, pharmaceutical, liquor, and food processings. Membrane microfiltration behavior is characterized by intrapore diffusive deposition of fine particles, surface pore blocking, and the formation of a thin cake layer on the filter surface. The intrapore diffusive deposition process predominates and it can be regarded macroscopically as a first-order rate process. The surface pore blocking process is also described by a first-order rate equation. Thus the filtration characteristics, such as filtration rate and filtration resistance, can be evaluated by using the macrokinetic models derived from first-order rate equations. The microfiltration processes were simulated numerically by these models and the calculation results agreed well with experimental observations. The backflushing stages must be included in a practical microfiltration process. A first-order rate process was proposed for the detachment process of collected particles from filter pores. Membrane microfiltration systems with backflushing stages were also evaluated macrokinetically and the effect of backflushing on the filtration performance was manifested numerically.     

陶瓷微滤膜澄清中药提取液的研究

本文对无机陶瓷膜错流过滤澄清中的中药提取液进行研究,考察了澄清效果,研究了操作压差,流速等条件对膜通量的影响,对污染机理进行了初步分析;采用多各清洗剂交替清洗使膜通量得到很好的恢复,研究表明,采用陶瓷微滤膜进行了中药提取液的澄清是一极有前途的新技术。     

苦瓜皂甙的复合酶法提取与大孔树脂纯化工艺研究

研究了苦瓜皂甙的酶法提取和大孔树脂纯化工艺.与高温水提法相比,苦瓜皂甙的复合酶解提取具有提取速度快、条件温和的优点.利用微孔技术精制提取液,除去一些大分子化合物和多糖.微滤后的精制液上LSA-20大孔树脂柱进行纯化,乙醇洗脱,冷冻干燥洗脱液所得的产品苦瓜皂甙含量可达79%.     

Flux Improvement during Cross-flow Microfiltration of Wheat Starch Suspension using Turbulence Promoter

The objective of this study was to investigate the effects of the process variables (transmembrane pressure, flow rate, and concentration) on the permeate flux during the microfiltration of model starch suspensions, and to determine the conditions under which the use of Kenics statics mixer as a turbulence promoter is justified. A response surface methodology was used to examine the influence of the selected operating conditions on starch suspension microfiltration using a single channel ceramic membrane with 200 nm pore size. The experimental results clearly show that the improved performance of starch suspension cross-flow microfiltration can be obtained by using a Kenics static mixer, especially at lower flow rates. Compared to the operation without the turbulence promoter, the average permeate flux improvement during the filtration period ranged from 30% to 230%. As a result of the statistical analysis, the optimal conditions for starch suspension microfiltration were determined and applied to microfiltration of starch industry wastewater.     

陶瓷微滤膜处理钛白生产废水研究

对陶瓷微滤膜处理钛白生产废水过程中工艺参数对膜性能的影响进行考察,获得了适宜的工艺条件：膜孔径为１．０μｍ,操作压力在０．２０ＭＰａ左右,错流速率２～５ｍ／ｓ、操作温度视工厂余热情况确定,适于在２０～５０℃,浓缩可以在膜通量维持基本不变的情况下在一定浓度范围内进行,同时确定了选择合适的操作压力的简便方法,起到了节省实验材料和时间的作用。     

Fuzzy Modeling of the Permeate Flux Decline during Microfiltration of Starch Suspensions

Flux declines versus time during cross‐flow microfiltration of wheat starch suspensions were modeled using fuzzy logic systems under different conditions of transmembrane pressure, flow rate, and suspension concentration. Fuzzy modeling is one of the most efficient methods for empirical modeling, especially for non‐linear systems, and does not require any prior knowledge about the process. The influence of the process parameters on the dynamic behavior of the permeate flux was determined by comparing the permeate flux decline versus the volume curves, considering a constant value of the volumetric concentration factor during batch cross‐flow filtration. At the transient stages of the filtration process, the permeate flux was shown to be strongly dependent on all process parameters, within the examined range.     

Modeling the Flux Decline during Protein Microfiltration: A Comparison between Feed-Forward Back Propagation and Radial Basis Function Neural Networks

Flux decline under various operating parameters in cross-flow microfiltration of BSA (bovine serum albumin) has been studied. A hydrophobic PES (polyethersulfone) membrane with an average pore diameter of 0.2 µm was used in all experiments. The experiments were carried out to investigate the effect of protein solution concentration and pH, trans-membrane pressure (TMP), cross-flow velocity (CFV), and membrane pore size on the flux decline trend and membrane rejection at constant trans-membrane pressure and ambient temperature. Subsequently, the experimental data, as a relatively large data set, have been subjected to a modeling study using both feed-forward back-propagation (BP) and radial basis function (RBF) artificial neural network (ANN) models. It is shown that through appropriate selection of parameters, it is possible to model the process accurately. Furthermore, it is concluded that the prediction capacity of RBFNN is superior to the BPNN, especially in the case of membrane rejection prediction.     

悬浮液体系错流微滤过程研究

对悬浮液体系的错流微滤（ＣＦＭＦ）过程进行理论分析和实验研究，探讨了料液类别、浓度、循环流速及操作时间、压力等参数对ＣＦＭＦ性能的影响。建立了稳态ＣＦＭＦ过程的简化组合模型，对过程的计算具有现实意义。