纳滤和生化工艺处理染整废水

根据染整废水的特点，选用纳滤膜分离和生化处理的方法处理染整废水。纳滤系统对CODcr的平均截留率达到97％，纳滤系统出水已经达到染整水再生回用要求和GB8978-1996的一级排放标准，可直接回用到染整工艺的清洗用水。纳滤膜对染整废水的处理可以维持稳定的膜通量，纳滤膜浓缩液与织布废水混合后，提高了污水的可生化性，膜浓缩液作为原生化系统的进水，从而使生化池的处理效率提高，生化处理系统出水达到了GB8978-1996的三级排放标准。     

纳滤膜分离技术及其进展

纳滤技术是一种介于超滤和反渗透之间的新型分离技术。作者介绍了纳滤膜的特性及其独特的分离特点。高分子纳滤膜的几种主要制备方法的制备原理、制备要点,国内外纳滤膜在生产研究方面的进展,以及当前已商品化的几种主要的纳滤膜的材质。最后简单介绍了纳滤膜在水处理、食品、生化、医药、染料和化工等领域的应用进展,指出今后的发展将着重于传质机理、新的膜材料及集成工艺开发等方面。     

耦合分离膜对悬浮型光催化纳滤膜反应器耦合工艺特性的影响研究

以阿特拉津(atrazine)模拟废水作为处理对象,采用3种不同种类和性质的纳滤膜与悬浮型光催化氧化过程进行耦合构成悬浮型光催化纳滤膜反应器的废水耦合处理工艺,比较耦合纳滤分离膜的种类和性质对光催化膜反应器处理atrazine模拟废水耦合工艺特性的影响.实验得出,由于对目标污染底物及主要光催化降解中间产物出色的选择性分离截留效果,将TS-60与光催化膜反应器进行耦合处理目标废水的处理效果最佳.     

纳滤膜分离技术在废水处理中的应用

纳滤作为一种新型分离技术，在处理废水的同时能够回收有用物质，因而在废水处理中得到了越来越广泛的应用。首先简介了纳滤膜分离技术的原理及特点，然后论述了纳滤膜的分离机理，接着介绍了用于表述膜的结构与性能之间关系的空间电荷、固定电荷和细孔等数学模型，最后对纳滤膜在生活污水、石油工业废水、化学工业废水、食品工业废水、造纸废水、印染废水、酸洗废液、重金属废水和电厂二次废水处理中的应用作了较全面的综述。     

纳滤膜的制备与应用

目前,纳滤膜应用于饮用水处理行业已引起业界广泛的关注与研究。纳滤膜是一种介于反渗透膜与超滤膜之间的水处理膜,有着较高的渗透和截留性能;纳滤膜一方面能截留水体中大部分的微量污染物质,另一方面保留水体中对人体有益的矿物质。文中主要讨论了纳滤膜的制备方法、分离机理、表征方法、污染以及在饮用水方面的应用和所面临的瓶颈,并探讨了纳滤膜技术今后的发展工作。可以看出,纳滤膜在饮用水处理领域有着广阔的应用前景。     

纳滤膜功能材料研究进展

饮用水安全问题纳滤膜,无机膜材料,有机膜材料日益成为现代社会关注的热点.纳滤膜因其独特的分离特性,成为饮用水深度处理的最佳选择之一,本文简要回顾了纳滤膜的历史,综述了近年来一系列纳滤膜制膜材料包括无机纳滤膜材料和有机聚合物纳滤膜材料.重点介绍了聚合物纳滤膜材料的种类和特性,以及发展趋势.     

纳滤膜在化工废水处理中的实际应用

随着我国科学技术的不断进步,化工业中的废水处理水平也在逐步提高,各种新型技术被应用到实际生产中,其中比较典型的就是纳滤。作为一种新型的分离技术,它不仅可以有效处理化工废水,还能将其中的有效物质进行回收,提高利用率,所以在化工废水处理中的应用范围也越来越广。从纳滤膜分离技术的工作原理出发,以盐化工的废水处理为例,对纳滤膜实际应用进行了具体分析。     

纳滤在水处理中的应用研究进展

对纳滤膜的定义、特点、分类、制备方法等作了介绍,对纳滤膜处理地下水、地表水和工业废水的最新研究应用进展进行了较为全面的综述.最后指出对纳滤分离机理的进一步探究、新型纳滤膜开发及其性能的预测和表征等是今后人们对纳滤技术的研究重点.     

纳滤技术在工业废水处理中的应用研究

纳滤膜是介于反渗透膜和超滤膜之间的一种压力驱动膜,分离机理较反渗透膜和超滤膜复杂.由于具有分离选择性高、操作压力低、不需添加化学试剂、可回收有用物质等优点,纳滤膜在造纸废水、重金属废水、垃圾渗滤液、纺织废水等的处理及废水深度处理回用的研究、应用中受到高度重视,具有良好的应用前景.     

界面聚合聚酰胺纳滤膜渗透选择性能优化的研究进展

纳滤因其分离效率高、操作压力低、环境友好等优点,在废水处理、海水淡化和工业分离纯化等众多领域有着重要的应用。界面聚合法制备的聚酰胺（PA）纳滤膜是最为常用的纳滤膜种类之一。然而界面聚合反应速度快,如何通过调控界面聚合过程,优化纳滤膜选择分离层的结构从而提高渗透选择性,以满足不同领域对纳滤膜需求仍是亟需解决的问题。本文从影响界面聚合单体扩散因素的角度出发,综述了近年来PA纳滤膜渗透选择性能优化的研究进展,包括新型PA纳滤膜、纳米材料/PA混合基质膜及超薄PA纳滤膜3个方面,探讨了选择分离层结构调控与纳滤膜渗透选择性能优化的关系,最后指出目前界面聚合制备高渗透选择性PA纳滤膜在规模化、稳定性及可控性存在的问题,并对未来界面聚合纳滤膜在微观结构和聚合过程调控方面的研究进行了展望。     

纳滤膜在染料工业脱盐浓缩中的应用

对CA50(醋酸纤维素)纳滤膜的盐截留率和染料截留率进行了考察,并将CA50纳滤膜应用于染料工业脱盐浓缩,考察了膜污染现象,对综合效益进行了分析。结果表明,CA50纳滤膜的盐截留率较低,对染料则有很高的截留率：将CA50纳滤膜应用于黄染料工业生产中,使主体染料的纯度提高20％,对黑染料膜分离过程进行优化,当盐浓度保持在5％时能获得最佳的脱盐效果;膜分离蓝色染料一段时间后,会造成膜污染,引起膜污染的物质主要是油污、无机物、有机物和染料分子,通过适当的预处理和清洗可以保持膜通量和防止膜污染：采用膜分离工艺使染料工业在经济、环境和社会效益得到提高．     

陶瓷纳滤膜处理淋浴污水及膜的清洗

采用无机陶瓷纳滤膜对淋浴污水进行分离特性试验,重点探讨了膜通量随时间的衰减情况以及操作压差、污水温度和pH值等操作参数对淋浴污水处理效果和膜通量的影响;并就陶瓷膜的污染对膜的清洗方法进行了初步研究。研究结果表明,陶瓷纳滤膜对淋浴污水中COD、TOC和浊度均有一定的去除效果,用水洗＋碱洗＋酸洗的综合清洗方法可以获得较好的清洗效果     

Separating Cyanide from Coke Wastewater by Cross Flow Nanofiltration

Investigations on separation of cyanide from coke wastewater were carried out in a cross flow nanofiltration membrane module following microfiltration of real industrial wastewater. Different composite polyamide nanofiltration membranes were used in the system while studying their effectiveness in cyanide separation under different operating conditions. Transmembrane pressure, pH, and cross flow velocity exhibited strong influence on percentage removal of cyanide. 94% cyanide rejection with a permeate flux of 79 liters per hour at a transmembrane pressure of 13 kg/cm² and at a volumetric cross flow rate of 700 liters per hour was achieved. The membrane module with a composite membrane having high negative charge was successfully operated without any significant loss in flux even after 72 hours operation. These encouraging results show that microfiltration and nanofiltration with properly selected membranes in an appropriate module could lead to a practical solution to a longstanding problem of cyanide removal from industrial wastewater.     

Concentration and diafiltration of aqueous fluorescent whitener solution by nanofiltration

Concentration and desalination of NT dye solutions by nanofiltration were studied experimentally with a spiral-wound nanofiltration membrane element. The decrease of permeation flux and increase of the observed NaCl rejection were observed due to the formation of the gel layer and possibly the precipitate layer on the membrane surface due to the high bulk NT concentration. By analyzing concentration polarization of NaCl at the membrane-solution interface, a simple empirical correlation between the permeation flux and the interfacial mass transport coefficient was obtained and coupled with a simplified S-K model for prediction of concentration and desalination of NT solutions. The concentration polarization was investigated using the simplified model that complied with the theoretical understanding. Several operations were compared, which resulted in an optimized technology for potential field implementation.     

纳滤膜脱盐性能及其在海水软化中应用的研究

选择了ESNA1型纳滤膜对NaCl、MgCl2、Na2SO4、MgSO4等4种无机单盐水溶液体系进行分离实验;考察操作压力和料液浓度等的变化对纳滤膜分离性能的影响及纳滤膜脱盐的稳定性,得到一些纳滤膜脱盐的规律;并对ESNA1膜在人工海水和海水软化脱盐中的应用作了初步探索.无机盐体系脱盐实验结果显示:随操作压力升高和料液浓度增大,ESNA1膜对4种盐溶液中的离子的截留率分别增大和减小,操作压力和料液浓度的变化对一价盐溶液的截留率影响较大,对二价盐溶液的截留率影响较小.人工海水和海水软化脱盐试验结果显示:ESNA1纳滤膜在实验过程中稳定性好,在较低的操作压力下膜通量也较高,且ESNA1纳滤膜对Ca2 、Mg2 、SO42-离子的截留率均＞90%,初步判断此种纳滤膜可用于海水软化预处理.     

纳滤/反渗透膜处理重金属废水的性能

The performance of different nanofiltration （NF） and reverse osmosis （RO） membranes was studied in treating the toxic metal effluent from metallurgical industry. The characteristics and filtration behavior of the processes including the wastewater flux, salt rejection and ion rejection versus operating pressure were evaluated. Then the wastewater flux of RO membrane was compared with theoretical calculation using mass transfer models, and good consistency was observed. It was found that a high rejection rate more than 95% of metal ions and a low Chemical Oxygen Demand （COD） value of 10 mg·L^-1 in permeate could be achieved using the RO composite membrane, while the NF rejection of the salt could be up to 78.9% and the COD value in the permeate was 35 mg·L^-1. The results showed that the product water by both NF and RO desalination satisfied the State Reutilization Qualification, but NF would be more suitable for large-scale industrial practice, which offered significantly higher permeate flux at low operating pressure.     

Advances in Polymeric Nanofiltration Membrane: A Review

The nanofiltration membrane was first introduced during late 1980s possessing properties between reverse osmosis and ultrafiltration membrane. Nanofiltration membranes have been used for applications including food industry, pharmaceutical, wastewater treatment, and desalination. This review presents an inclusive outlook of recent research and advances in polymeric nanofiltration membrane technology. Various methods were reported for nanofiltration membrane preparation particularly through electron beam irradiation, UV/photografting, layer by layer, plasma treatment, interfacial polymerization, and nanoparticle incorporation. Nanofiltration membranes were reported to remove microorganisms, turbidity, dissolved salts, and hardness. Major problem in application is nanofiltration membrane fouling, thus efforts regarding fouling mitigation are discussed.     

Effect of the drying temperature on sulfonated polyether sulfone nanofiltration membranes prepared by a coating method

This study reports on the preparation of a novel sulfonated polyether sulfone nanofiltration membrane via a manual coating method. The as-prepared membrane was modified by changing the drying temperature and utilizing additives. As the drying temperature was increased, the rejection performance of the as-prepared nanofiltration membrane increased, while flux decreased. The nanofiltration membrane dried at 40°C had relatively high permeation flux and good rejection performance for divalent ions and dyes; therefore, it is suitable for dye wastewater treatment. The nanofiltration membrane dried at 50°C had relatively low permeation flux and relatively good rejection performance for inorganic salts. The pore size of the skin layer was reduced as the drying temperature was increased. The average diameters of the as-prepared nanofiltration membranes dried at 40 and 50°C were 5.08 and 1.51 nm, respectively. Due to excellent hydrophilicity and relatively low roughness, the as-prepared nanofiltration membranes dried at 40 and 50°C had superior antipollution characteristics.     

单通道陶瓷膜管低压透水性能实验分析

无机陶瓷膜作为多孔介质具有分离效率高、耐酸、耐碱等优点,被视为在海水淡化、废水处理、气体分离等领域的研究热点。采用Al₂O₃管式单通道陶瓷膜材料构建膜组件,以燃煤电厂自来水、烟气冷凝水、脱硫废水三种不同水质为例,开展低跨膜压差下的膜组件透水性能实验,研究了膜参数、跨膜压差及水体温度等因素对渗透通量、渗透水质的影响,并对引发膜污染的机理过程进行了探讨分析。实验结果表明：陶瓷膜管的结构参数是关键因素,如孔隙率、孔径及厚度等;低跨膜压差下的渗透通量随压力增大呈线性提高,并未发现浓差极化现象,水体温度变化通过改变黏度进而影响渗透通量,同时水质较差时会导致渗透通量降低;陶瓷膜管的孔径是影响渗透水质的核心要素,微滤与纳滤膜对改善悬浮物含量、浊度及色度效果明显,不同孔径对盐度、电导率影响不同;从SEM图可以看出,污染物在膜表面或膜内部发生的沉积、架桥等现象导致严重的膜污染。充分认识影响陶瓷膜管渗透特性的关键因素及污染物的作用机理,对提高无机陶瓷膜的应用前景具有重要意义。     

纳滤膜淡化苦咸水技术现状及进展

介绍了苦咸水的危害,综述了纳滤的原理及其独特的分离特点、影响纳滤膜脱盐效率的因素以及纳滤膜在苦咸水淡化中的应用现状。