一种基于膜污染指数的超滤膜污染评价方法

利用浸没式中空纤维膜小试系统,基于膜污染指数（FI）建立超滤膜污染的评价和试验方法。通过试验考察超滤膜污染变化规律,以及运行周期对膜污染指数计算的影响,并确定计算膜污染指数的运行周期;并对膜污染指数评价方法的可重复性进行检验：对化学清洗前后膜污染指数进行比较。试验表明,在过滤初期,滤饼污染和吸附污染并存,所以初期水力不可逆膜污染指数（HIFI）增长较快;中期超滤膜的吸附能力不断减弱,膜污染主要是滤饼污染,所以膜污染较为稳定：后期跨膜压力过大,压缩滤饼层,减小滤饼孔隙率,增加滤饼阻力,所以HIFI有所增加。同时短期的膜污染试验可以用来反映长期的膜污染情况,该超滤膜污染的评价方法重复性好,污染后的超滤膜经过化学清洗后。可以重复利用。     

用酶溶液清洗被酱油污染的超滤膜研究

膜污染降低了超滤法澄清酱油的经济性和实用性,本文通过红外光谱定性分析得出酱油对聚砜超滤膜的主要污染物为蛋白质和固形物。分别用胰蛋白酶溶液,氢氧化钠溶液清洗被酱油污染的聚砜超滤膜,并结合二者作用得出最佳的两步清洗流程,清洗效率可达９５％以上。通过ＳＥＭ分析得出污染主要发生在膜表面形成凝胶层,并分析了胰蛋白酶－氢氧化钠溶液清洗流程的作用机理,高效的清洗流程和温和的清洗条件可增强超滤膜性能并延长膜的使用     

丝厂废水中的丝胶蛋白在超滤过程中的膜污染和膜清洗

采用十种不同的膜清膜方法对超滤丝厂废水后被污染的中性聚砚中空纤维超滤膜进行了研究。结果表明：０．１％ＮａＯＨ、０．５％ＮａＣｌＯ、０．１％渗透剂等组成的碱性溶液对丝胶蛋白造成的膜污染具有最佳清洗效果。     

超滤法在抗生素提炼中的应用

超滤膜法用于去除抗生素提炼精制中的蛋白质分子。截留分子量为１×１０４的中空纤维超滤膜能有效去除料液中的蛋白质分子，消除提炼过程中的乳化现象，各项试验产品指标达到或超过了生产标准要求。此外，对膜污染机理进行了探讨，确定了清洗方法和清洗条件     

管式膜海绵球清洗

通过分析污染根源、污染物和海绵球清洗的试验,设计了清洗某管式超滤膜污染的工艺,成功完成了该管式膜工业清洗项目,洗后膜性能恢复率达到95%以上。     

超滤膜处理地表水过程中膜污染的研究进展

膜污染是制约超滤膜大规模应用的一个主要原因.本文参考国内外文献,针对超滤膜处理地表水过程中膜污染的研究进展进行综述,其中包括产生膜污染的相关理论,影响因素,清洗方法等.     

操作条件对膜污染及蛋白质超滤滤出速度影响的研究

蛋白质溶液的超滤是超滤膜应用的重要领域之一蛋白质溶液的性质是影响超滤性能的重要因素，当蛋白质溶液性质一定时，操作条件成的影响超滤性能至关重要的因素，本文通过对不同材质超滤膜超滤蛋白质溶液地的操作条件与膜污染和滤出速度关系的研究，提出了蛋白质超滤时操作条件的优越方案。     

超滤膜法浓缩新型苏云金杆菌（Bt）杀虫剂

本文研究了用超滤膜方法浓缩新型苏云金杆菌杀虫剂，简称“新型Ｂｔ”，并对几种不同材料的超滤膜的污染程序 及污染后膜的最佳清洗方法作了初步实验。结果表明：采用Ｐ＝０．１５ＭＰａ，Ｐ＝０．０５ＭＰａ，操作条件效果比较好，反洗方法简单易行，能达到最佳清洗效果。     

水处理中超滤膜污染成因及其控制方法研究

超滤膜污染是限制超滤膜在水处理得到应用的重要因素，它直接导致超滤工艺的运行维护费用增加，膜使用寿命大幅度缩短等。本文首先总结了超滤膜污染的原因、膜污染类型及主要影响因素，综述了膜前预处理技术、膜清洗技术、改性膜应用等目前控制膜污染的主要方法以及超滤与其它工艺组合控制膜污染新方法，最后指出了超滤膜污染防治未来的发展趋势。     

超滤膜清洗技术研究进展

超滤膜清洗的研究对超滤膜技术广泛应用具有重要意义。重点阐述目前超滤膜应用过程中膜污染的清洗技术研究进展,简要展望超滤膜清洗技术的发展方向。     

一种新型喹唑啉酮衍生物A与牛血清白蛋白作用的研究

应用荧光光谱和紫外可见吸收光谱研究了A与牛血清白蛋白间的结合作用,确定了A对牛血清白蛋白的荧光猝灭过程的猝灭机理。测定了不同温度下该结合反应的结合常数,结合位点数,热力学参数。依据能量转移理论确定了A和蛋白间的结合距离。采用同步荧光技术考察了A对牛血清白蛋白构象的影响,并讨论了A与蛋白的结合模式。     

A study of the interaction between fluorescein sodium salt and bovine serum albumin by steady-state fluorescence

The binding of fluorescein sodium salt with three kinds of commercially available bovine serum albumin (BSA) of different grades of purity was investigated at 288, 298 and 313 K by fluorescence and absorption measurements at pH 7.50. The association and dissociation constants K_a and K_d were determined by the quenching of BSA fluorescence in the presence of fluorescein sodium salt. The best results were obtained by fitting raw data by non-linear regression and Lineweaver–Burk equations. The modified Stern–Volmer and Scatchard plots gave less reliable data since the fitting was much more difficult.The agreement of the constants for the three sets of measurements coming from the different BSA was not as good as expected. BSA binding properties differ depending on the different BSA grades of purity. Actually, the binding constants found for the three BSAs used differed in the same set of interactions, even by keeping the experimental conditions constant. These results are a novelty in the field of BSA–ligand binding studies and should be taken into account for future binding studies using BSA. Actually, a large number of aspects should be considered including the grade of purity and the presence of BSA covalent and non-covalent dimers, trimers and oligomers in solution which can affect the goodness of the binding results.     

Cibacron Blue F3G-A Attached Poly(Vinyl Alcohol) Particles for Specific Albumin Adsorption

Abstract

Poly(vinyl alcohol) (PVAL) particles (average size: 50 μm) were prepared in the present study by chemical crosslinking of PVAL with glutaraldehyde in an organic dispersion oil phase. Cibacron Blue F3G-A was attached to these hydrophilic PVAL particles. Bovine serum albumin (BSA) adsorption onto these dye-attached PVAL particles from aqueous solutions containing different amounts of BSA in three different salts (i.e., NaCl, CaCl₂, and NaSCN) at different pH and ionic strengths was investigated in batch reactors. The maximum adsorption capacity (about 35 mg BSA/g dye-attached PVAL) was observed around pH 6.0 in a medium containing NaCl with an ionic strength of 0.01. Nonspecific BSA adsorption on plain PVAL particles was almost zero. About 90% of the adsorbed BSA was desorbed by using a 0.5 M NaSCN desorption medium for 1 hour.     

Congo red- and Zn(II)-derivatized monosize poly(MMA-HEMA) microspheres as specific sorbent in metal chelate affinity of albumin

Monosize poly(methylmethacrylate-hydroxyethylmethacrylate) [poly(MMA-HEMA)] microspheres (4 μm in diameter) were produced by dispersion copolymerization of MMA and HEMA in an ethanol-water medium. Congo Red was attached to the poly(MMA-HEMA) microspheres, covalently. These Congo Red-derivatized microspheres were characterized by optical microscopy, Fourier transform infrared spectroscopy, and elemental analysis. Then, Zn(II) ions were incorporated by chelating with the immobilized Congo Red molecules. Different amounts of Zn(II) ions [1.2–17.6 mg of Zn(II)/g of polymer] were conjugated on the microspheres by changing the initial concentration of Zn(II) ions and pH. Bovine serum albumin (BSA) adsorption on these microspheres from aqueous solutions containing different amounts of BSA at different pH and ionic strengths was investigated in batch reactors. The nonspecific BSA adsorption on the plain poly(MMA-HEMA) microspheres was very low (0.7 mg of BSA/g of polymer). Congo Red derivatization significantly increased the BSA adsorption (up to 35.8 mg of BSA/g of polymer). A further increase in the adsorption capacity (up to 61.0 mg of BSA/g of polymer) was observed when Zn(II) ions were incorporated. More than 90% of the adsorbed BSA was desorbed in 1 h in the desorption medium containing 1.0M NaSCN at pH 8.0. © 1997 John Wiley & Sons, Inc.     

Synthesis and Characterization of PEG-Modified Polystyrene Particles and Isothermal Equilibrium Adsorption of Bovine Serum Albumin on these Particles

A series of monodisperse submicron polystyrene (PS) particles with different surface monomethoxy poly(ethylene glycol) (mPEG) densities were prepared and characterized. The effects of the chemically grafted mPEG chains (MW = 2,000) on the adsorption of bovine serum albumin (BSA) molecules onto these negatively charged particles at pHs 5 and 3 were investigated. The native particles at both pH values showed the largest values of q _max (maximum amount of BSA adsorbed on the particle surface). The surface mPEG chains were very effective in retarding the BSA adsorption and q _max decreased significantly with increasing surface mPEG density. The values of q _max were greater for both the native and mPEG-modified particles at pH 5 compared to those counterparts at pH 3, due to the different adsorption mechanisms. Hydrophobic interaction predominated in the adsorption of BSA molecules on the particles at pH 5, whereas electrostatic interaction had a crucial influence on the BSA adsorption at pH 3. At pH 5, the adsorption behaviors were qualitatively explained by the calculated values of the free energy barrier against the BSA adsorption. A schematic model was also proposed to qualitatively describe the conformations of BSA molecules adsorbed on the particle surfaces.     

药根碱与牛血清白蛋白相互作用的光谱研究

采用荧光和UV光谱法研究了盐酸药根碱(Jat)与牛血清白蛋白(BSA)相互作用的光谱特性.结果表明:Jat对于BSA荧光猝灭主要是静态猝灭和非辐射能量转移;Jat浓度增大,BSA荧光峰被猝灭的同时出现峰裂分现象,原来345 nm处的单峰逐渐裂分为二重峰,其中一峰峰值蓝移,另一峰峰值红移至λcm=362～365 nm;测...     

Comparative Study of Enantioseparation of Racemic Tryptophan by Ultrafiltration Using BSA-Immobilized and BSA-Interpenetrating Network Polysulfone Membranes

Effectiveness of Bovine Serum Albumin (BSA) as chiral recognizing protein in enantiomers separation by ultrafiltration technique was studied by immobilizing BSA on the membrane and incorporating BSA as semi-interpenetrating network in the membrane matrix. Separation of racemic tryptophan solution was performed in closed loop cross flow ultrafiltration using BSA immobilized polysulfone membrane and polysulfone membrane having BSA semi-IPN network. The volumetric flux (J_v), the solute flux (J_s), the separation factor (α), and the enantiomeric excess (%ee) of two types of membranes at different trans-membrane pressures and permeation times were determined. BSA semi-IPN membrane exhibits higher volumetric as well as solute fluxes compared to BSA immobilized membrane. Separation factor (α) to the order of 1.89 was achieved with BSA immobilized membrane after 8 h of ultrafiltration and in the same duration BSA-IPN membrane exhibited separation factor (α) to the order of 1.62. BSA immobilized membrane exhibits higher enantiomeric excess (30.8%) compared to BSA semi-IPN membrane (23.8%) after 8 hrs. BSA molecules available on membrane as immobilized or as semi-IPN under go complexion with tryptophan enantiomers differently. BSA immobilized membrane performed better separation and enantiomeric purity; however, the solute flux of the membrane decreases.     

4种金属卟啉配合物与血清白蛋白作用的光谱研究

应用荧光光谱法研究了4种金属卟啉配合物5-(4-羧基苯基)-10,15,20-三苯基卟啉锌、钴、镍、锰(MCPPZn、MCPP-Co、MCPPNi、MCPPMnCl)与牛血清白蛋白(BSA)的结合反应。探讨了金属卟啉配合物对BSA内源荧光的猝灭机理,根据不同温度下的结合常数判断金属卟啉配合物与BSA之间具有较强的结合作用,对BSA内源荧光的猝灭过程为静态猝灭。根据热力学参数确定了MCPPZn与BSA之间的作用力以静电引力为主,MCPPCo(25和42℃下)、MCPPNi、MCP-PMnCl与BSA之间的作用力以氢键和范德华力为主。分析了结合常数和作用力类型的差异主要是由中心金属离子的电负性和外层d轨道上的电子数的不同而引起的。     

一种吡喃并噻吩并嘧啶酮衍生物与牛血清白蛋白的相互作用研究

采用荧光光谱法,研究了不同温度下、pH值为7.4时,3-对氯苯基-2-(四氢吡咯-1-基)-5,6,8-三氢吡喃并[3′,4′:4,5]噻吩并[2,3-d]嘧啶-4(3H)-酮(PPTP)与牛血清白蛋白的相互作用;计算了不同温度下二者的结合常数和结合位点数;并用同步荧光技术讨论了PPTP衍生物对牛血清白蛋白构象的影响....     

荧光法研究Gemini表面活性剂与BSA的相互作用

应用荧光法研究了Gemini表面活性剂(G14-3-14)与牛血清白蛋(BSA)在不同温度条件下的荧光猝灭现象,利用荧光猝灭双倒数图计算了G14-3-14与BSA之间的结合常数,并根据热力学参数确定了二者之间的作用力类型.用内源荧光法求得它们在30℃和35℃温度下的结合常数分别为K1=1.01×105 L·mol-1和...