进水盐度对膜生物反应器运行效能的影响研究

进水盐度对膜生物反应器(MBR)的运行效能影响显著,尤其是进水含盐量为5 g/L时,明显恶化了污泥可滤性,膜污染速率加快;MBR混合液中溶解性微生物产物(SMP)和胞外聚合物(EPS)含量随钠离子浓度变化而变化,其中SMP中蛋白质含量与钠离子浓度密切相关;与紧密结合态EPS(TB)相比,钠离子含量对松散结合态EPS(LB)浓度的影响更大;不同盐度对COD及NH4+-N影响不明显,系统对COD及NH4+-N的去除效果稳定,分别保持在92%及94%以上,高盐度对MBR总磷去除率降低明显。     

不同价态铁离子对膜生物反应器影响研究进展

膜生物反应器(Membrane bioreactor,MBR)作为一种新型的污水处理技术,近些年来备受关注。然而,膜污染问题成为了该工艺广泛应用的最大障碍。现已证明,向MBR中投加铁系混凝剂能够减缓膜污染。本文首先综述了不同价态铁离子对MBR污染物去除的影响,然后对铁离子在污泥混合液中分布及迁移转化进行了分析,接着阐明了铁离子对膜污染的影响,最后对该领域的研究进行了展望。     

NaClO原位清洗对膜生物反应器生物膜污染影响研究进展

膜生物反应器(MBR)的膜污染问题严重制约了该工艺进一步快速的商业化推广,全面认识NaClO原位氧化清洗对MBR生物膜污染的影响,对于开发新型膜清洗技术及MBR工程优化具有重要意义。本文从微生物胞外关键组分空间分布角度综述了NaClO原位清洗对生物膜污染及生物絮凝的影响,并探讨了生物絮体重构机制及强化生物絮凝的相关措施。最后,本文从减缓膜污染的角度,对该领域未来的研究方向进行了论述。     

膜生物反应器中AHL分析技术研究进展

膜生物污染一直是膜生物反应器(membrane bioreactor,MBR)在废水处理工艺中需要解决的一大难题。最近研究表明：基于群体感应的淬灭技术可以作为MBR活性污泥体系中一种有效的膜生物污染防治策略。因而,识别和分析群体感应产生的信号分子是应用群体淬灭技术防治MBR中膜生物污染的关键。本文首先介绍了活性污泥体系中的群体感应机理和N-酰基高丝氨酸内脂(N-acyl homoserine lactone,AHL);其次,归纳近期研究中针对MBR中AHL定性和定量分析方法;最后,对MBR中AHL识别及分析技术应用进行了展望。     

无膜生物电化学制氢反应器的产气特性

研究了无膜生物电化学制氢反应器的设计及产气特性。设计和组装的电化学制氢反应器为无膜电化学制氢反应器。它是以碳毡作为阳极,以负载一定量Ni-Al-Sn（Ni-50%、Al-45%、Sn-5%）合金粉催化剂的石墨板作为阴极,乙酸钠作为电解质。其工作原理是在两极间外加一定电压,阳极区的微生物降解有机物产生电子到达阴极,质子在阴极得到电子生成氢气。主要考察了阳极碳毡数量、环境温度、外加电压等因素对产气速率和氢气选择性的影响。结果表明,当阳极面积为900cm²、环境温度为30℃、外加电压为0.9V时,反应器产气速率最高可达4.21m³/(d·m³),氢气选择性最高为70.4%。     

膜生物反应器在废水处理中的应用及研究

膜生物反应器是将生物反应器与膜分离技术相结合的一种高效废水处理新技术。介绍了膜生物反应器的类型、特点以及其在处理生活污水、工业废水、垃圾渗透液、粪便污水和中水回用中的研究和应用现状,提出了膜生物反应器所存在的问题及其研究进展。     

酶膜反应器及其在生物催化领域的应用

酶膜反应器是一种新型的生物催化反应设备,它是反应与分离相耦合的装置,集产品分离、纯化和酶回收利用于一体,具有其它方法不可比拟的优势。在强调资源节约,环境友好和清洁化生产技术的今天,显示一些特别的优点,近年来已成为热门的研究领域。本文主要介绍了酶膜反应器的基本原理、特征及其分类,并根据分类对近年来酶膜反应器在生物催化领域...     

大蒜素包埋球对膜生物反应器混合液可滤性影响解析

将由大蒜素包埋在海藻酸钠中制成的大蒜素包埋球(AEBs)投加至膜生物反应器(MBR)中,以探讨大蒜素的群体猝灭(QQ)效应对MBR污泥混合液可滤性的影响。结果表明,QQ作用对污泥混合液性质影响显著,对MBR污染物去除影响较小;混合液中胞外聚合物(EPS)和溶解性微生物代谢产物(SMP)含量降低;通过对修正污染指数(MFI)检测表明,QQ可提高污泥混合液可滤性,该指标与胞外多糖浓度紧密相关。     

膜生物反应器中N-酰基高丝氨酸内脂分析技术研究进展

膜生物污染一直是膜生物反应器(Membrane bioreactor,MBR)在废水处理工艺中需要解决的一大难题。新近研究表明,基于群体感应的猝灭技术可以作为MBR活性污泥体系中一种有效的膜生物污染防治策略。因而,识别和分析群体感应产生的信号分子是应用群体猝灭技术防治MBR中膜生物污染的关键。本文首先介绍了活性污泥体系中的群体感应机理和N-酰基高丝氨酸内脂(AHLs)类化合物;接着,归纳了近期研究中针对MBR中AHLs定性和定量分析的方法;最后,对MBR中AHLs识别及分析技术的应用前景进行了展望。     

Effects of Sludge Concentrations and Different Sponge Configurations on the Performance of a Sponge-Submerged Membrane Bioreactor

The performance of a novel sponge-submerged membrane bioreactor (SSMBR) was evaluated to treat primary treated sewage effluent at three different activated sludge concentrations. Polyurethane sponge cubes with size of 1?×?1?×?1?cm were used as attached growth media in the bioreactor. The results indicated the successful removal of organic carbon and phosphorous with the efficiency higher than 98% at all conditions. Acclimatised sponge MBR showed about 5% better ammonia nitrogen removal at 5 and 10?g/L sludge concentration as compared to the new sponge system. The respiration test revealed that the specific oxygen uptake rate was around 1.0?C3.5?mgO₂/gVSS.h and likely more stable at 10?g/L sludge concentration. The sludge volume index of less than 100?mL/g during the operation indicated the good settling property of the sludge. The low mixed liquor suspended solid increase indicated that SSMBR could control the sludge production. This SSMBR was also successful in reducing membrane fouling with significant lower transmembrane pressure (e.g. only 0.5?kPa/day) compared to the conventional MBR system. Further study will be conducted to optimise other operating conditions.     

双凝胶剂中第一凝胶剂对聚砜中空纤维膜结构的影响

采用双凝胶浴法研究了第一凝胶剂(水、甘油、乙醇、丙酮和正己烷)对聚砜中空纤维膜近外表面处结构的影响。结果表明,第一凝胶剂的延迟时间越长,所制得的膜的近外表面处越疏松,铸膜液溶剂与第一凝胶剂之间溶解度参数差值(△δm)越大,制得的皮层结构越致密;第一凝胶剂瞬时分相时,易产生大孔结构,但当第一凝胶剂为非水溶性的正己烷时,尽管第一凝胶剂延迟分相而第二凝胶剂瞬时分相也产生大孔膜结构。     

对三氧化二铁催化性能的思考

用Fe2O3作催化剂分解过氧化氢制氧气的实验中发现其催化效果微弱,与文献比较严重不符。据此,阐述了Fe2O3在化工生产中的催化性能及其催化作用机理,指出不同晶型Fe2O3的催化剂性能差异较大,并分析了其催化过氧化氢分解时会产生不同效果的原因。研究发现,在实验室条件下,γ-Fe2O3晶型具有较强的催化活性,而长期保存的Fe2O3粉末经灼烧30 min后有助于提高其催化活性。     

Impact of Membrane Types and Catalyst Layers Composition on Performance of Polymer Electrolyte Membrane Fuel Cells

Performance of a low temperature polymer electrolyte membrane fuel cell (PEMFC) is highly dependent on the kind of catalysts, catalyst supports, ionomer amount on the catalyst layers (CL), membrane types and operating conditions. In this work, we investigated the influence of membrane types and CL compositions on MEA performance. MEA performance increases under all practically relevant load conditions with reduction of the membrane thickness from 50 to 15 μm, however further decrease in membrane thickness from 15 to 10 μm leads to reduction in cell voltage at high current loads. A thick anode CL is found to be beneficial under wet operating conditions assuming more pore space is provided to accommodate liquid water, whereas under dry operating conditions, an intermediate thickness of the anode CL is beneficial. When studying the impact of catalyst layer thickness, too thin a catalyst layer again shows reduced performance due to increased ohmic resistance ruled out the performance of the MEAs which have identical Pt crystallite sizes on the cathode CLs i. e. the thinnest the cathode CL, the highest the voltage were achieved at a defined current load. Adaptation of the operating conditions is highly anticipated to achieve the highest MEA performance.     

COMSOL软件在枸杞多糖超滤膜生物反应器中膜阻塞模型构建中的应用

基于聚砜中空纤维超滤膜分离技术精制枸杞多糖（Lycium barbarum polysaccharide）,通过COMSOL软件对枸杞多糖膜阻塞逆流提取及超声设备参数进行修正,获得更优的纯化工艺。采用微波-超声法提取枸杞多糖,并利用聚砜中空纤维超滤膜对枸杞多糖进行分离,采用单因素分析及正交实验考察枸杞多糖提取和分离过程中的重要参数,通过COMSOL软件对重要膜阻塞参数进行修正。结果表明,枸杞多糖提取较优工艺条件为：提取温度50~70 ℃之间,超声功率50 W,固液比例1∶8~1∶12（mg∶mL）,提取时间40~60 min;当超滤膜截留相对分子质量为1×10⁴时,膜通量较好;正交实验结果表明,膜通量与料液温度关系最大,其次是膜pH值和分离操作压;COMSOL软件对枸杞多糖连续逆流提取设备进行仿真计算,结果发现与全封闭叶片相比,开孔叶片能够显著降低溶剂短路现象,使得最低流速提升高达65倍。基于COMSOL软件数据修订,枸杞多糖分离效率得到大幅度提升,为枸杞多糖工业化生产提供必要的数据积累。     

漆酚铁聚合物的制备及性能研究

以生漆和三氯化铁反应制备漆酚铁聚合物,用红外光谱、涂膜鲜映性仪和光泽度仪等对聚合物结构和漆膜性能进行表征.结果表明,反应温度65℃,反应时间3h,漆酚和三氯化铁物质的量比为8∶1,所生成的漆酚铁聚合物性能较好.     

Influence of Extracellular Polymeric Substances on Membrane Fouling and Cleaning in a Submerged Membrane Bioreactor

There is little information available on the correlation between the concentration of extracellular polymeric substances (EPS) and membrane fouling as well as cleaning efficiency. In this study, two lab-scale flat submerged membrane bioreactors (SMBRs) at sludge retention times (SRTs) of 25 and 250 days were operated at a constant permeate flux (12.5 l m⁻² h⁻¹). Samples of activated sludge were tested to quantify the concentration of extractable EPS using cation exchange resin. Batch filtration tests were also performed to determine the specific cake resistances and the flux recoveries. The extractable EPS and protein concentrations were relatively low at the prolonged SRT, leading to cake layers easily removable by the physical manual cleaning or the de-ionized water backwashing and the chemical cleaning with sodium hypochlorite methods. The extent of flux recoveries (both in SMBRs and batch filtration tests) and macroscopic as well as microscopic images indicated that the chemical cleaning could enhance the effectiveness of cleaning. The membrane fouling and cleaning mechanisms were also discussed.__________From Kolloidnyi Zhurnal, Vol. 67, No. 3, 2005, pp. 392–397.Original English Text Copyright © 2005 by Chackrit Nuengjamnong, Ji Hyang Kweon, Jinwoo Cho, Kyu-Hong Ahn, Chongrak Polprasert.This article was submitted by the authors in English.     

凝固浴温度对PVDF-g-PNIPAAm温度敏感膜成膜过程与性能的影响

通过自由基共聚的方法制备了聚偏氟乙烯-g-聚(N-异丙基丙烯酰胺)(PVDF-g-PNIPAAm)共聚物,采用浸没沉淀相转化法制备了PVDF-g-PNIPAAm共聚膜.采用超声时域反射法研究了不同凝固浴温度下PVDF-g-PNIPAAm的成膜动力学,并研究了凝固浴温度对膜结构与性能的影响.结果表明,在不同凝固浴温度下,...     

内凝固浴组成对聚醚酰亚胺中空纤维膜结构和性能的影响

以N,N-二甲基乙酰胺(DMAc)为溶剂,水为外凝固浴,乙醇为内凝固浴,DMAc为内凝固浴添加剂,采用相转化法制备了聚醚酰亚胺(PEI)中空纤维膜,研究了内凝固浴组成和纺丝液浓度对膜结构和性能的影响。实验结果表明,随着内凝固浴中DMAc含量在一定范围内增加,纤维断面指状孔有所减少,内表面由无孔到有微孔出现,但膜的水通量下降,截留率不受影响;随着纺丝液浓度提高,膜的水通量下降,截留率提高。