电渗析海水淡化技术研究进展

海水作为水资源的重要组成部分,其有效利用是解决我国水资源短缺、优化淡水资源配置的重要途径之一。电渗析装置于20世纪50年代实用化,促使电渗析海水淡化技术取得突破性进展。本文主要对电渗析海水淡化技术的发展状况进行了介绍,如电渗析海水淡化技术的基本原理、电渗析技术的国内外发展历程、电渗析海水淡化技术面临的挑战及电渗析技术的最新研究进展等,重点介绍了现阶段电渗析技术与其他膜技术的集成工艺在海水淡化中的应用,并简单讨论了电渗析海水淡化技术的发展前景。     

煤矿苦咸水淡化技术的研究

根据原水水质,水量和处理要求,确定采用浓水部分循环电渗析淡化工艺和阻垢措施,并给出工艺流程,主要工艺设计参数和经济指标等,实践证明,该技术具有工艺合理,占地面积少,运行稳定可靠,维修工作量小等特点,值得推广。     

反渗透技术在苦咸水淡化工程中的应用

西安美星精密环保设备股份有限公司采用掺渗透装置,对咸阳国际机场供水进行净化,淡化处理,使水质较差,不宜用的Ⅲ级水成为符合国家生活饮用水卫生标准和卫生组织饮水水质准则的优质水。运行结果表明,反渗透技术处理含氟苦咸水是比还原沉淀法,电渗析法更为有效可行的水处理先进技术。     

大钦岛电渗析苦咸水淡化工程长期进行探析

本文介绍了我国第一处为海岛提供生活饮用水的电渗析地下苦咸水除盐示范工程。并对该工程连续运行12年之后,设备仍处于良好状态,保持了总供水量不减少、产品水质不降低、运行维修费用稳定在经济范围之内的原因进行了探析。     

新型苦咸水脱盐电渗析系统

新型苦咸水脱盐电渗析系统ＴａｋｕｏＫａｗａｈａｒａａｎｄＴｏｓｈｉｋａｔｓｕＨａｍａｎｏ２５－１４Ｋａｍｅｉｄｏ２－ＣｈｏｍｅＫｏｕｔｏｕ－ｋｕ，Ｔｏｋｙｏ１３６，Ｊａｐａｎ电渗析用于苦咸水脱盐已有多年。然而，随着目前对地下水适度去除盐分和硝酸盐污染...     

苦咸水淡化研究进展

在我国农村,很多地区居民深受地质的盐碱、苦咸、高氟的困扰。本文介绍苦咸水的化学类型、苦咸水的危害及苦咸水的分布现状,比较了电渗析法、蒸馏法、反渗透法、电吸附法、冷冻法和纳滤法等淡化方法的优点与不足,从而能更有效解决农村饮用水问题。     

风力发电——电渗析淡化苦咸水示范站的研建与运行

针对海岛风力资源丰富，但用电用水困难的问题，用风力发电－电渗析淡化苦咸水法成功地解决了海岛用电、吃水问题，具有较大的实用意义和社会效益。     

苦咸水反渗透淡化技术的研究

随着社会的继续进步发展,与此同时原有的水资源受到了严重污染,使得地球上水资源日益紧缺.这不仅限制了社会的发展,还危害到了人类的生存.为了缓解水资源紧张的情况,苦咸水的处理再利用无疑成为了解决水问题的最佳途径.本文回顾了近年来国内外反渗透膜、新能源和能量回收技术在苦咸水反渗透淡化中的研究进展情况,并提出了一些发展中遇到的问题,为苦咸水反渗透淡化技术的发展提出了一些建议.     

海水和苦咸水淡化

现有苦咸水和海水淡化方法有许多种,主要是蒸馏法、电渗析法和反渗透法。目前苦咸水淡化大多采用反渗透法和电渗析法,主要是反渗透法,在海水淡化方面,主要是蒸馏法和反渗透法。虽然现有淡化容量的70％是蒸馏法,主要是多级闪蒸,然 而这种局面正在变化,反渗稼法以其人氏投资费和低能耗,大有后来居上的趋势。近年来,无论是苦咸水淡化还是海水淡 化,其 市场占有率,反渗透点有绝对的份额。     

电渗析膜污染与清洗技术研究进展

电渗析技术作为一种膜分离技术,随着对传统电渗析过程的改进,使电渗析技术成为新的热门研究领域。而研究离子交换膜的污染规律,建立起有效的缓解和清除膜污染措施,是解决电渗析技术更广泛应用的一个关键问题。本文分析了电渗析膜污染的成因和污染的防治,并对电渗析膜的清洗方法做了综述。     

Antifouling membrane based on sodium alginate coated polyamide thin film composite for desalination of brackish water

Sodium alginate coated polyamide thin film composite (SA/PA-TFC) membranes were synthesized for the desalination of brackish water through reverse osmosis. Membranes were characterized by Fourier transform infrared spectroscopy, x-ray diffraction, scanning electron microscopy, AFM, thermogravimetry, and universal testing machine for structural analysis, crystallinity, morphological, compositional, thermal, and mechanical properties, respectively. The effect of feed pressure on water flux and % salt rejection was quantified. Simulation results generated using the commercial process simulator PRO/II were in good agreement with the experimental data. Case studies using simulator were performed for brackish water with different salinity to optimize operating pressure based on product unit cost (PUC) by varying the feed pressure and membrane area. The calculated PUCs were found to be 0.9 and 0.3 $/m³ for corresponding feed total dissolved solids (TDS) concentrations of 5000 and 500 mg/L at an optimum pressure of 10 bar, to achieve a salt rejection of 98% using a membrane area of 335 m². We believe these membranes are a prospective solution for brackish water desalination.     

A computer simulation of continuous ion exchange membrane electrodialysis for desalination of saline water

A computer simulation program including the principle of ① mass transport, ② current density distribution, ③ energy consumption and ④ limiting current density is developed for predicting desalinating performance of a continuous (one-pass flow) electrodialysis process. In this simulation the following parameters are inputted; ① membrane characteristics such as overall transport number, overall solute permeability, overall electro-osmotic permeability, overall hydraulic permeability, direct current electric resistance etc. ② electrodialyzer specifications such as flow-pass thickness, flow-pass width and flow-pass length of a desalting cell etc. and ③ electrodialytic conditions such as current density, electrolyte concentration in a feeding solution, linear velocity in desalting cells, standard deviation of normal distribution of solution velocity ratio etc.In a practical-scale electrodialyzer, electrolyte concentration in a desalting cell is decreased along a flow-pass and it gives rise to electrolyte concentration distribution. It causes electric resistance distribution and current density distribution. Solution velocities in desalting cells vary between the cells, and give rise to solution velocity distribution. In this simulation, these distributions are taken into account assuming that the frequency distribution of solution velocity ratio is equated by the normal distribution. Further, the influences of electrodialyzer specifications and elctrodialysis conditions described above on the performances of an electrodialyzer (desalting ratio, current efficiency, electrolyte concentration at the outlets of desalting cells, cell voltage, energy consumption, electrolyte concentration distribution, current density distribution, and limiting current density) are predicted. The simulation model is developed on the basis of the experiments and its reasonability is supported by the performance of electrodialyzers operating in salt-manufacturing plants.     

电渗析脱盐过程离子传递现象的数值模拟

建立了电渗析脱盐过程离子传递稳态模型,研究了离子电荷数、离子扩散系数和离子交换膜电导率对脱盐过程传质的影响,描述了离子浓度分布、电势分布和离子传递通量分布的变化情况。研究表明:相较于一价离子,二价离子在电渗析过程中膜两侧浓度差较小,跨膜电压降较高,各项传递通量较小;当离子扩散系数增大时,膜两侧浓度差减小,跨膜电压降升高,总传递通量和电迁移通量增大;当离子交换膜电导率增大时,膜两侧浓度差增大,跨膜电压降降低,各项传递通量均增大。     

A computer simulation of batch ion exchange membrane electrodialysis for desalination of saline water

A computer simulation program is developed for predicting desalinating performance of a batch electrodialysis process. The program includes the principle of ① mass transport, ② current density distribution, ③ cell voltage, ④ mass balance/energy consumption and ⑤ limiting current density. In this simulation the following parameters are inputted; ① membrane characteristics such as overall transport number, overall solute permeability, overall electro-osmotic permeability, overall hydraulic permeability, direct current electric resistance etc., ② electrodialyzer specifications such as flow-pass thickness, flow-pass width and flow-pass length in a desalting cell etc. and ③ electrodialytic conditions such as voltage, electrolyte concentration in a feeding solution, linear velocity in desalting cells, standard deviation of normal distribution of solution velocity ratio etc.The following phenomena were computed and discussed; ① Changes of electrolyte concentration and current density with operation time. ② Influence of cell voltage on operation time (batch duration), water recovery and energy consumption. ③ Influence of volume of an electrolyte solution prepared at first on operation time. ④ Influence of cell voltage, electrolyte concentration and standard deviation of solution velocity ratio in desalting cells on limiting current density. ⑤ Energy consumption in a reverse osmosis process. ⑥ Excepting limiting current density, the performance of an electrodialyzer is never influenced by the standard deviation of normal distribution of solution velocity ratio in desalting cells. ⑦ Energy consumption in electrodialysis is less than that in reverse osmosis at feeding saline water concentration less than about 2000 mg/l.     

电渗析技术研究现状与进展

简述了电渗析技术的几种类型,并对电渗析技术在水处理、食品和化工方面应用的研究现状和发展前景进行了综述。     

A study of ionic transfer in electrodialysis process with laminar flow

The concentration profile in a laminar flow of the diluent of a parallel-plate electrodialysis stack is derived by assuming operation at the limiting current density. The Nusselt mass transfer number is found to depend on the Reynolds number, the Schmidt number and the dimensionless hydraulic equivalent diameter according to (Nu)_theo. = 3.7 · (Re · Sc · de/L)^1/3. An empirical correlation of the Reynolds number, the Schmidt number, and the shape factor of the electrodialysis cell, with the ionic mass transfer rate in ion exchange membrane electrodialysis is obtained by measuring the limiting current densities at various conditions. The resulting empirical mass-transfer correlation, (Nu)_exp. = 3.91 · Re^0.333 · Sc^0.328 · (de/L)^0.352, holds for sodium acetate as dialysate at concentrations ranging from 0.0106 to 0.0508 kmol/m³, viscosities ranging from 0.608 to 0.926 mPa · s, temperatures ranging from 15 to 55°C, axial velocities ranging from 0.341 to 4.55 cm/s, and for cell thicknesses of 0.32 and 0.94 cm, and is found to be in agreement with the equation obtained from theory. The effects of concentration, flow rate and temperature on the limiting current density are also studied. The relationship between the thicknesses of the diffusion layer and the Reynolds number has been analyzed.     

双极膜电渗析技术的研究进展

双极膜电渗析技术(BMED)是利用直流电场作用下双极膜界面层内发生水解离生成H+和OH-这一电化学特性,通过将双极膜与阴、阳离子交换膜适当组合,可实现不同的特种分离功能。与传统工艺相比,BMED具有高效节能、环境友好、操作便捷等突出技术优势。本文介绍了3种不同的BMED工作模型以及BMED在有机酸生产、水除盐、蛋白分离、超纯水制备等领域的最新研究进展,对BMED技术的进一步研究与发展进行了展望。     

反渗透海水淡化膜法预处理技术研究进展

简要论述了反渗透海水淡化的各种新型膜法预处理技术研究进展情况及其在国内外的具体运用情况,内容主要涵括连续微滤技术(CMF)、浸没式帘式膜过滤、超滤技术、纳滤技术以及陶瓷膜过滤.并指出膜法预处理将成为今后反渗透海水淡化预处理的主要发展方向.     

Optimal design of an electrodialysis brackish water desalination plant

This paper considers the optimal design and operation of electrodialysis (ED) desalination plants. In general an ED plant aims to produce potable water from a high salinity source, like brackish water or high salinity water. The system is modelled mathematically as mixed-integer non-linear programming (MINLP) optimization problem, determining the number of desalination stages, the membrane area, the total required energy so as to minimise the total annualised cost of the investment accounting for both infrastructure and operating costs. Two examples from the literature illustrate the applicability of the proposed approach and evaluate the quality of the results obtained.     

关于电渗析除盐系统的节水问题

电渗析除盐设备在我国已被广泛地用来生产软化水、纯净水,但目前的电渗析系统水利用率很低,有的电渗析设备水利用率仅在４０％左右。广泛地使用这样的电渗析设备造成水资源的大量浪费。究其原因,主要是设计者和制造者的盲目性所致。文中介绍了自动频繁例极浓水循环电渗析除盐系统的节水方法和原理,从而制定了在不同的原水水质,不同的除盐率要求的情况下,水的利用率应该达到指标。避免了盲目排放所谓浓水,并为排放的浓水含盐量