Polysaccharide separation mechanism in polysulfone-Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> magnetic composite membranes

Polysulfone (PSF)-Fe3O4 composite membranes were prepared by the phase-inversion process and their polysaccharide separation mechanism was explored using chondroitin sulfate (CS) and dextran. The mechanism was analyzed from constraints on the magnetic field and geometric deformation. It was found that variations in dextran rejection from 58% to 46% were mainly influenced by the geometric deformation of the composite membrane, while the magnetic field had a significant influence on variations in CS rejection from 82% to 35%. The results indicate that it is possible to continuously separate different types of polysaccharide with a composite membrane by adjusting the external magnetic field.     

Photocatalytic degradation of metronidazole in aqueous solution by niobate K<Subscript>6</Subscript>Nb<Subscript>10.8</Subscript>O<Subscript>30</Subscript>

The photocatalytic degradation of antibiotic metroni-dazole in aqueous solution by niobate K6Nb10.8O30 photocatalyst that was prepared using a soft-chemical method was studied by Fourier transform infrared spectroscopy and UV-Vis absorption spectrum. Metronidazole is very stable and is difficult to degrade under UV irradiation. K6Nb10.8O30 photocatalyst cannot degrade metronidazole without UV irradiation and shows very high photo-catalytic activity for the degradation of metronidazole under UV irradiation. The photocatalytic degradation rate of metronidazole increased with increasing the dosage of K6Nb10.8O30 photocatalyst. The photocatalytic degradation reaction of metronidazole by nio-bate K6Nb10.8O30 follows the first-order kinetic equation.     

膜分离技术在再生水中的应用及膜污染研究进展

传统的废水处理工艺在一定程度上成功地处理了排放的废水.然而,改善废水处理工艺是必要的,以便使处理后的废水能重复使用.膜技术已成为从不同的废水中回收再利用水的最佳选择.介绍了超滤膜、反渗透膜、微滤膜和纳滤膜的特征,阐述了这些膜在再生水中的研究近况以及膜污染的类型和清洗方法,最后展望了膜工艺在再生水中的应用与发展.     

生物丁醇的渗透蒸发分离膜研究进展

丁醇的分离问题是生物丁醇工业化及应用过程中急需解决的难题之一.从不同发酵-分离耦合技术的分离效果和经济效益出发,分析了渗透蒸发技术在丁醇分离中的优势.综述了渗透蒸发分离丁醇发酵液或模拟发酵液的研究进展,对聚二甲基硅氧烷(PDMS)、聚三甲基硅-1-丙炔(PTMSP)及其改性膜和其他聚合物膜的特点与分离性能进行了总结.另外,还关注了支撑液膜在丁醇分离中的应用及其存在的稳定性问题,分析了丁醇发酵液中存在的溶剂小分子、中间产物及生物大分子等对分离性能的影响.最后,对用于生物丁醇分离的渗透蒸发膜的未来发展进行了展望.     

Preparation and characterization of in-site regenerated TiO<Subscript>2</Subscript>-ACFs photocatalyst

In-site regenerated titanium dioxide-activated carbon fibers (TiO₂-ACFs) photocatalyst was prepared by the sol-gel method. Detailed surface and structural characterization of the TiO₂-ACFs photocatalyst was carried out. The photoactivity of TiO₂-ACFs under ultraviolet irradiation was compared with original ACFs and pure TiO₂ by the degradation of methylene blue aqueous solution. The degradation efficiency by the TiO₂ (5wt%)-ACFs sample is much higher than that by TiO₂ and ACFs. The results show that the photocatalysis by TiO₂-ACFs is a six-step process. The adsorption-transfer-photocatalysis rate of TiO₂-ACFs is higher than the adsorption-photocatalysis rate of TiO₂, so the photocatalysis rate of the TiO₂-ACFs system is higher than that of TiO₂ photocatalyst.     

膜分离技术及其在发酵液后处理中的应用

介绍了膜分离技术的原理以及发酵液后处理过程中常用的提取精制方法 ,如吸附、沉淀、结晶、萃取、离子交换等。介绍了膜技术在抗生素、维生素、氨基酸、酶制剂及其他发酵液后处理过程中的应用现状。实现膜技术在生产过程中的应用需要在膜与物料的适应性、适宜的操作条件和清洗、再生等方面进行研究 ,使后处理过程在低成本、高收率下进行     

耐酸性分子筛膜的研究进展

分子筛膜是一种可以实现分子筛分的新型无机膜,是膜分离技术的重要组成部分.分子筛膜在分离过程中具有浓缩、纯化、分离和反应促进等作用,且能耗较低,是理想的膜分离和膜催化材料.随着工业的发展,物质的提纯、化学反应过程中产物的分离等分离条件愈加苛刻,对分子筛膜的耐酸性、抗腐蚀性等要求越来越高.因此,耐酸性和抗腐蚀性分子筛膜的制备技术和表征技术有待改进和完善,进而促进膜分离技术在工业生产中发挥更大的作用.主要介绍了耐酸性分子筛膜的制备以及应用现状,并展望了耐酸性分子筛膜在工业方面的发展前景.     

炭膜的制备及应用

炭膜是一种新型的无机功能分离膜,与传统的高分子分离膜相比,炭膜具有耐高温、耐氧化性、耐腐蚀能力强的优点.选择廉价易得的炭膜制备原料,研究和制备高性能的气体和液体分离用炭膜,提高膜的通量和膜分离过程的选择性,一直是国内外研究人员不断探索的目标.研究炭膜催化反应器、炭膜生化反应器、集成膜反应器以及无机-有机复合膜是今后的发展方向.     

渗透汽化分离膜及膜反应器 Ⅰ．聚离子复合腹性能的研究

通过两层复合制得壳聚糖－聚丙烯酸钠和壳聚糖－褐藻酸钠聚离子复合膜，研究了其对乙醇－水混合体系的分离性能，并比较了壳聚糖膜、聚丙烯酸钠、褐藻酸钠及聚离子复合膜对乙醇－水二元体系和乙酸－丁醇－乙酸丁酯－水多元体系的渗透汽化分离性能．结果表明，聚离子复合膜适于作膜反应器的膜材料．     

膜型生物反应器酒精发酵与分离耦合过程的动力学模型

提出了利用无机硅沸石膜组成的膜型生物反应器进行发酵和分离过程中乙醇连续发酵与渗透气化分离的耦合模式,并根据发酵和膜分离过程初步提出反应动力学模型。