反渗透膜生物污染的影响因素及控制方法的研究进展

由于人口的增长和淡水资源的短缺,各种水处理技术应运而生,其中RO技术作为一项新兴膜分离技术,在海水淡化、污水处理、再生水回用等方面都有着广泛的应用。但是膜污染问题的存在,成为膜技术在饮用水和污水处理中广泛应用的瓶颈。其中生物污染对膜的破坏性最为严重,其污染也最难控制。回顾了生物污染的形成过程,主要列举了影响生物膜初始形成的几种因素:菌体特性、膜表面特性、进水组分等。同时讨论了生物污染的控制和预防方法,包括预处理、RO膜表面改性和微生物群体感应抑制。最后根据目前国内外的研究现状,展望了生物污染未来的研究前景。     

反渗透系统中生物污染及控制研究

由于人口增长和淡水资源缺乏,各种水处理技术逐渐被应用,作为一项新兴膜分离技术—RO技术,被广泛应用于海水淡化、污水处理、再生水回用等方面.然而,膜技术在饮用水和污水处理过程中会出现各种膜污染问题,这也是该技术在应用过程的瓶颈.其中,生物污染对膜的破坏力最大,污染问题也很难控制.回顾了生物污染的形成过程,主要列举了影响生...     

双胍基化聚乙烯胺改性制备抗生物污染反渗透膜

反渗透作为一种高效、低能耗的膜分离技术,在使用过程中极易受到生物污染的侵袭,造成膜性能不可逆下降。制备具有杀菌功能的反渗透膜可以有效缓解膜生物污染问题。采用二次界面聚合法,将合成的双胍基化聚乙烯胺（PVAmG）阳离子聚合物引入到初生反渗透膜表面,制备出具有杀菌功能的PVAmG改性反渗透膜。结果表明,改性后膜表面的微观形貌和润湿性变化不大,在中性条件下膜表面荷正电。PVAmG改性膜在不降低膜选择透过性能的同时,有效提高了抗生物污染性能。PVAmG改性膜与枯草杆菌和大肠杆菌连续接触4次后,膜面细菌死亡率每次均接近99.9%,表明PVAmG改性膜具有持久的广谱杀菌性。     

复合反渗透膜的研究进展

反渗透膜具有亲水性好、允许pH值范围宽、操作压力低,脱盐率高、耐污染等优点,目前,复合反渗透膜在反渗透膜市场占据了主导地位,广泛应用于海水淡化、苦咸水脱盐、水处理、纯净水制取等领域。本文对复合反渗透膜研究进展,复合反渗透膜的制备,复合反渗透膜的抗污染改性及发展趋势进行综合评述。     

反渗透膜在水处理中的研究进展

简要概述了反渗透原理及反渗透膜的种类,重点介绍反渗透膜在城市污水、垃圾渗滤液、重金属废水及含油废水处理和回用方面的应用,最后分析了目前反渗透膜存在的问题及其发展趋势。     

陶瓷膜的生物污染控制及其抑菌改性

陶瓷膜因其具有耐高温高压、耐腐蚀、耐有机溶剂、膜通量高和使用寿命长等优点被广泛运用于水处理、食品饮料、医药、化工、电子以及环保等领域.但陶瓷膜的污染尤其是生物污染成为制约其实际运用的-个重要因素,因此陶瓷膜的抑菌改性越来越受到人们关注.本文论述了陶瓷膜生物污染过程及其控制方法,介绍了常见的无机抑菌材料和目前抑菌陶瓷膜的相关研究现状和趋势.     

反渗透膜污染及防控研究进展

随着淡水资源的短缺问题日益严重,反渗透膜分离技术在水处理中的应用越来越广泛。然而,反渗透系统运行过程中遇到的最大问题就是膜污染,膜污染会降低膜的效能,缩短膜的使用寿命,增加系统的运行费用。因此,加强对反渗透膜污染和清除方法的认知,为后续的设计及运维提供借鉴。     

反渗透膜的污染及其控制

本文综合分析了引起反渗透膜污染的各种物质的形成特点及其危害，井针对每种污染提出了预防与控制措施。     

反渗透膜清洗技术及研究进展

系统分析了造成膜污染的污染物类型和形成原因,并指出应该根据不同的污染情况选择合适的清洗方式和方法,以及物理、化学和生物三种清洗方法的特点及适用范围。总结了近年来反渗透膜清洗技术的研究进展,包括新型的清洗剂组合物配方和新型清洗装置。     

高分子反渗透膜材料改性研究进展

介绍了反渗透膜的高分子材料及其衍生物材料的种类,叙述了改性方法及研究进展,提出了今后的研究方向.     

反渗透膜有机污染的研究进展

介绍了反渗透进水中一些主要有机污染物质的污染机理以及操作条件、膜自身特性、溶液化学性质对于污染过程的影响,还综述了预处理技术、清洗方法以及通过膜的表面改性等措施来控制反渗透膜的有机污染,最后指出了目前研究中需关注的一些问题。     

Effect of N-acetylcysteine against biofouling of reverse osmosis membrane

The influence of (1.5 mg/mL) of N-acetylcysteine (NAC), a non-antibiotic, mucolytic agent, on the biofouling of a reverse osmosis (RO) membrane by a multi-species culture (four environmental strains) of biofilm forming bacteria was studied. NAC was found to considerably suppress the formation of the biofilm on the RO membrane. The inhibitory effect of NAC on biofilm formation was verified by image based studies. There was over a 70% reduction in biofilm surface coverage when grown in the presence of NAC. Similarly, the average thickness and total biomass content of the biofilm formed in presence of NAC were significantly less than those of the control. These results suggest that NAC could be a potential agent for the control of biofouling of a RO membrane. However, the chemical stability, potential toxicity and consistent performance of NAC in the field will have to be further investigated for optimization of its use on a field scale.     

Microbial community in seawater reverse osmosis and rapid diagnosis of membrane biofouling

Due to the acceleration of global warming and the stress that population growth has placed on the global water supply, seawater reverse osmosis (SWRO) desalination is arising as a promising technology to overcome the stress placed on current water resources. However, the biofouling of RO membranes is a common problem, as it causes flux decline, demands frequent cleanings, and consumes high energy, resulting in a shortened lifespan of the system. In an attempt to address these issues, detailed knowledge of the microbial bacteria present, which have a strong correlation between biofilm community structure and operational problems, is ultimately expected to lead to greater control of biofouling. Furthermore, a more rapid diagnosis of biofilm bacteria in SWRO processes is required for faster process feedback. In this study, previous approaches that have been proposed for understanding, diagnosing, and predicting biofouling are reviewed. Finally, the future outlook towards controlling biofouling in SWRO is discussed.     

Recent advances in reverse osmosis and electrodialysis membrane desalting technology

The potential impact of recent developments in both reverse osmosis and electrodialysis membrane desalting technology are summarized.Particular emphasis is given to the status of advanced technology reverse osmosis membranes with chlorine resistance having single pass seawater desalination capability. Membranes capable of using low operating pressures for brackish water desalting are also reviewed.Results obtained with large prototype reverse osmosis modules and their potential effect on lowering plant capital costs are presented.Possible elimination of acid and use of ultrafiltration as the predominant pretreatment step in seawater desalination plants are also described.Recent developments in the high temperature electrodialysis program for seawater desalting and in the use of newly developed anion membranes for brackish water desalination are reviewed.Finally, the effect of recent budget cut-backs imposed on the office of Water Research and Technology (OWRT) and potential impacts on future membrane desalination R&D activity are discussed.     

正渗透膜分离的研究进展

正渗透是浓度驱动的膜技术,是指水通过选择性渗透膜从高水化学势区域向低水化学势区域的传递过程。本文介绍了正渗透的基本构成（驱动力、汲取液和正渗透膜材料）,指出膜两侧的浓差极化是水通量性能的最大障碍,采用通量模型说明了膜在两种放置方向下存在的内浓差极化和外浓差极化,内浓差极化对驱动力的减小起着重要的作用;论述了膜材料、原料液浓度、汲取液浓度对正渗透和压力延迟渗透水通量的影响;此外,评述了正渗透过程的膜污染和能耗。     

Recent advances in reverse osmosis membranes

A review is presented of the developments of the past several years in the area of reverse osmosis membranes. These developments have occurred along two lines: new membrane materials and new membrane fabrication methods. Among the new materials can be cited aromatic polyamides, polybenzimidazole, polyphenylene oxide, hydrated metal oxides, crosslinked and blended cellulose acetates, crosslinked polyvinylpyrrolidone, crosslinked polyethylenimine, and derivatives of several of these materials. The water and salt permeabilities of many of these materials and of the cellulose acetates are compared.Important developments in the area of fabrication methods include the extension of asymmetric membrane techniques to new materials, supported ultra-thin films, hollow fibers and asymmetric hollow fibers, and dynamically formed membranes. A comparison of these materials and fabrication methods requires some kind of figure of merit and one such parameter is discussed.     

High-temperature reverse osmosis membrane element

Polymeric thin-film composite (TFC) reverse osmosis (RO) membranes in a patented spiral-wound element configuration were evaluated at process temperatures to 90°C. The viability of the membrane elements operating at high temperature was successfully demonstrated. The high temperature RO (HT-RO) membrane elements are suitable for a variety of dewatering, concentrating and component separation applications in liquid food and beverage processes that operate at an elevated temperature.

In this paper, the performance of HT-RO elements for dewatering high temperature sugar solutions is highlighted. Also discussed are the special design features of the HT-RO element as well as its performance characteristics at high temperatures.     

抗污染芳香聚酰胺反渗透膜研究进展

聚酰胺反渗透膜具有选择透过性高、化学稳定性好等优点,在水处理领域应用广泛。但膜污染导致的通量下降、寿命降低等问题严重制约了其发展与应用,开发抗污染反渗透膜是缓解膜污染的重要手段。本文根据抗污染膜作用机理将抗污染反渗透膜分为抗黏附型、污染驱除型和杀菌型,综述了近年来相关方面的研究成果,并对合理组合多种机制制备抗污染反渗透膜的进展进行简要概括,最后对抗污染反渗透膜的发展前景进行了展望。     

中空纤维纳滤膜与反渗透膜的研究

根据界面聚合反应成膜原理,以哌嗪(PIP)或间苯二胺(m-PD)水溶液为水相,均苯三甲酰氯(TMC)正己烷溶液为有机相,以聚砜中空纤维超滤膜为基膜,制备了一系列聚酰胺/聚砜纳滤或反渗透复合膜.研究了水相浓度、有机相浓度、界面聚合时间和温度等条件对复合膜性能的影响.结果表明:中空纤维纳滤复合膜在0.4 MPa、室温条件下,对2 g/L MgSO_4水溶液的通量可达36.64 L/(m~2·h),截留率为97.2%;中空纤维反渗透膜在0.7 MPa、室温条件下,对0.5 g/L的NaCl水溶液通量可达12.2 L/(m~2·h),截留率96.5%.