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1.
分别选取一种内压式和一种外压式中空纤维膜超滤组件,从超滤膜材质、运行参数和出水水质等方面对这2种组件在海水淡化反渗透预处理中的应用做了比较。结果表明:由于超滤膜的材料不同,使得2种组件运行工艺有较大差异:内压式组件在跨膜压差和膜通量方面要好于外压式组件,而2种组件出水水质在同一水平上。在进水浊度小于20NTU时,内压式膜组件更适合作为反渗透的预处理工艺。  相似文献   

2.
选取两种内压式中空纤维超滤膜组件,从膜材质、运行参数和出水水质等方面对这两种组件在海水淡化反渗透预处理中的应用进行比较。结果表明:2#膜组件跨膜压差和膜通量的稳定性较1#组件好,两种膜组件出水水质比较接近,但2#膜出水水质稳定性较1#膜好。  相似文献   

3.
选取两种内压式中空纤维超滤膜组件,从膜材质、运行参数和出水水质等方面对这两种组件在海水淡化反渗透预处理中的应用进行比较。结果表明:2#膜组件跨膜压差和膜通量的稳定性较1#组件好,两种膜组件出水水质比较接近,但2#膜出水水质稳定性较1#膜好。在进水浊度小于20NTU时,2#膜组件更适合应用于反渗透的预处理工艺。  相似文献   

4.
采用混凝-超滤工艺对渤海湾海水进行了预处理实验,在50 L/(m2·h)和57.5 L/(m2·h)通量下考察了混凝-超滤系统的运行稳定性,研究了Fe Cl3混凝沉淀过程对超滤系统出水水质、跨膜压差及膜表面污染程度的影响。结果表明:在膜组件运行通量不超过60 L/(m2·h),温度高于14℃,Fe Cl3投量为6 mg/L时,超滤系统的跨膜压差较低,可长期稳定运行,超滤系统出水浊度小于0.15 NTU,SDI15稳定在2.0左右,达到反渗透进水水质要求。实验使用Darcy模型对膜阻力增长机理进行了分析,结果表明:Fe Cl3混凝预处理可有效减缓膜阻力的增长,特别是因膜孔内污染物堵塞和吸附产生的阻力。经过混凝沉淀预处理,膜表面的滤饼层明显松散并呈现絮体状,可有效阻挡小颗粒污染物进入膜孔内造成不可逆污染。  相似文献   

5.
将超滤技术(UF)与反渗透技术(RO)相结合,对某铜冶炼厂中水进行深度处理,出水作为全厂工业循环冷却水系统补充水和锅炉给水使用。重点监测了超滤系统及反渗透系统的运行情况,连续3 a的运行结果表明,超滤系统运行稳定,出水水质优于反渗透进水要求;RO出水经后处理后,水质满足《循环冷却水用再生水水质标准》(HG/T 3923—2007)和《工业锅炉水质》(GB/T 1576—2008)。  相似文献   

6.
针对大型膜法海水淡化中进水水质波动较大问题,采用正交对比法,对6种不同搭配的滤料体系进行了选型实验,并长时间对超大型卧式滤器在项目中运行数据的跟踪。结果表明,石英砂滤料在海水进水条件下,出水SDI_(15)较稳定,出水浊度较好,运行压降较小,为项目最合适滤料。超大型卧式滤器出水浊度稳定在0.2~0.25 NTU、SDI_(15)稳定在2.5左右,与超滤系统的实际出水水质相仿;压降上升速率约0.5 kPa/d。说明超大型卧式滤器作为混凝沉淀池+V型滤池后续的海水反渗透系统的二级预处理,其系统回收率远高于设计的95%。不仅大幅度地提高了整个系统的水利用率,还降低了运行的能耗。已具备在大型海水淡化工程中全面使用的条件。  相似文献   

7.
海水淡化过程中的超滤预处理中试研究   总被引:3,自引:0,他引:3  
超滤作为一种新型海水淡化预处理技术,近年来得到了广泛的关注,并在实际中得到应用.采用死端超滤技术对胶州湾海水进行预处理实验.试验采用UF-Ⅰ和UF-Ⅱ两种中空纤维膜组件,考察了两种超滤膜最佳操作参数以及对浊度的去除效果,分析了超滤系统产水通量以及出水淤泥密度指数(SDI_(15))随时间的变化情况.发现UF-Ⅰ的性能优于UF-Ⅱ,其出水SDI_(15)在2.0左右,对浊度的去除率100%.  相似文献   

8.
目前渤海湾反渗透海水淡化工程多采用新型的超滤膜法预处理工艺,为提高预处理效果,主要进行超滤膜材料和性能改进以及膜组件运行参数的优化,而对超滤膜前预处理的研究相对较少。本实验研究了超滤与混凝/超滤作为反渗透海水淡化预处理工艺的处理效果。考察了两种预处理工艺条件下浸没式超滤膜比通量(SF)、进水水质、产水水质,膜孔孔径变化、反洗效果及膜表面污染情况。结果表明,超滤与混凝/超滤两种预处理工艺都能达到产水SDI152.0;混凝处理可以大幅度降低海水中颗粒数目,降低颗粒物在膜表面沉积和吸附的概率,减轻超滤膜的污染。当采用混凝/超滤工艺时超滤膜表面滤饼层疏松多孔,膜孔孔径变化较小,超滤膜比通量的衰减速度减缓,反洗时超滤膜比通量恢复率较高。  相似文献   

9.
渤海湾反渗透海水淡化预处理新工艺   总被引:2,自引:1,他引:1  
通过对天津市1000m^3/d反渗透海水淡化示范工程及100m^3/d海水淡化工程预处理部分的对比试验,得到不同海水水质的预处理效果对比数据。试验结果表明,新预处理工艺可将出水浊度降低至1NTU以下,总铁含量可降低至0.1mg/L以下。和原预处理工艺比较,新预处理工艺具有占地面积小、运行成本低、出水水质优等优点。  相似文献   

10.
双膜法深度处理油田采出水的现场试验研究   总被引:5,自引:1,他引:4  
基于油田注汽锅炉给水的要求,利用商品膜组件,进行了(超滤+纳滤)双膜法深度处理油田采出水的现场试验研究.结果表明,超滤预处理效果良好,出水油的质量浓度小于0.06 mg·L~(-1),SDI_(15)小于4.0,满足了纳滤膜进水要求.氢氧化钠+十二烷基磺酸钠(SDS)复合清洗剂对超滤膜污染表现出较好的清洗效果,纯水通量恢复系数高达92%.在较高的回收率下,纳滤对硬度、总溶解固体(TDS)、SS、和COD仍保持高截留率,且保持了稳定的产水通量,系统出水水质达到油田注汽锅炉进水水质指标.(超滤+纳滤)双膜工艺在长期运行过程中,产水通量及水质表现出较高的稳定性.  相似文献   

11.
《分离科学与技术》2012,47(13):2663-2678
Abstract

In this work a straightforward procedure for the optimum design and operation of the seawater reverse osmosis (SWRO) plants is being proposed. The analysis is based on analytical equations for the permeate flow rate and quality and the salt flow rate. The mathematical model and the developed software can predict the brine and permeate characteristics for any SWRO plant regardless of the number of the membrane modules in the pressure vessels. The results of the developed software were verified by experimental data from a 280 m3/d RO plant, with 8″ membrane module made by FilmTec, and they were compared with the predictions made by ROSA 6.0 software. An excellent agreement was observed between the prediction of the suggested model and the experimental data. The model can be applied in any type of membrane modules as long as the geometry and the membrane characteristics are known.

Different operating conditions were tested and an effort was made for the optimum design and operation of the plant so that the minimum specific energy consumption can be achieved. It is believed that the analytical model presented in this work is a very useful tool not only because of its accuracy for the SWRO plant design and operation but also because of its simplicity.  相似文献   

12.
《Desalination》2007,202(1-3):239-246
This study evaluates the factors affecting pretreatment conditions for hybrid UF membrane processes for reuse of secondary effluent from the sewage treatment plant. The experimental results obtained from the ultrafiltration (UF) membrane process showed that the particles of the size range between 0.2 and 1.2 μm caused a significant impact on membrane fouling in all cases even with or without the coagulation process. As pretreatment of UF membrane process, the coagulation significantly improved the permeate flux. Optimal flux improvement was seen at an alum dose of 50 mg/L. In addition, it was found that the permeate flux was least declined under the coagulation condition of charge neutralization (pH 5.0). Also, the powdered activated carbon (PAC) adsorption enhanced the permeate flux. Application of the direct filtration as a pretreatment of UF membrane process was also very effective in reducing the UF membrane fouling.  相似文献   

13.
Recently, single-stage seawater reverse osmosis (SWRO) in the Middle East has been developed. In this process, removing dissolved oxygen (DO) from the feed seawater is very important for membrane life. The reaction rate of sodium bisulfite (SBS) and DO in seawater was investigated to apply DO removal system to the SWRO. The reaction in seawater was very fast because the salinity had a positive catalytic effect and the bicarbonate ion kept the pH suitable for the reaction. By applying these results, Toray's PEC-1000 membrane modules have shown excellent performance and long durability.  相似文献   

14.
姜周曙  翁翔彬  王剑  雷淳正 《化工学报》2014,65(6):2172-2178
故障树分析是一种逻辑演绎的故障诊断方法,在核反应堆和航天器可靠性等领域已得到成功应用。反渗透法是目前应用最广泛的海水淡化方法。“脱盐率与产水量下降”是反渗透海水淡化系统中最为典型且损失重大的故障类型。基于对反渗透海水淡化膜组件结构和系统工作流程与机理的深入分析,给出了“脱盐率与产水量下降”的故障树;利用布尔代数求出最小割集及最小径集,完成了对故障基本事件的结构重要度分析,对故障基本事件进行了危险等级划分并提出了上述故障的处理方法。研究工作为超大规模反渗透海水淡化故障诊断专家系统中知识库的构建提供了一套科学实用的方法。  相似文献   

15.
Noka Prihasto 《Desalination》2009,249(1):308-316
A good quality pre-treatment process is instrumental to the successful operation of a seawater reverse osmosis (SWRO) plant. The compounds that are susceptible to foul the reverse osmosis (RO) membranes are inorganic suspended solids, sand, oil, clays, bacteria, and dissolved organic matters. In order to prevent the fouling, a pre-treatment of the raw water needs to be conducted. The pre-treatment technologies to prevent membrane fouling and to extend the lifetime of the RO membrane are commonly grouped into two categories, conventional and non-conventional. Both of these treatments are currently applied in SWRO plants in the world. The pre-treatment system applied is highly site specific and depending on the type of the feed water. This paper reviews the recent representative researches that are related to SWRO antifouling strategies and answers the most crucial questions about design and operating parameters of SWRO and its pre-treatment process. Also the economic evaluation of the SWRO system in regards to antifouling strategies' experience is discussed.  相似文献   

16.
The critical and threshold flux theories represent an important advance in membrane knowledge. Comprehension of the flux behavior of ultrafiltration (UF) membranes is key to control the fouling issues during the steady operation of the plant. In this regard, differing between critical or threshold flux patterns in the treatment of wastewater effluents by UF is relevant to confirm the level of fouling expected and to verify if no fouling is predictable or if certain amount of fouling cannot be avoided. In the present study, the hydrodynamic behavior of a polymeric UF membrane was analyzed by means of both critical and threshold flux theories and diverse patterns were found depending on the feedstock pollutants concentration and particle size distribution. Results obtained from the pressure-cycling experiments point for a threshold flux pattern in the case of UF of the effluent derived from the extraction process (OMW) disregarding the applied pretreatment, whereas for 1:1 (v/v) mixture of the latter with the wastewater from the fruit washing (OWW) the membrane fits a critical flux trend, indistinctly of the performed pretreatment too, with negligible fouling below the critical conditions. These conclusions are supported by the experimental permeate flux profiles during batch-run operation experiments.  相似文献   

17.
Thomas C. Timmes 《Desalination》2009,249(3):895-5440
The objectives of this research were to investigate the use of in-line electrocoagulation (EC) as a pretreatment for seawater prior to ultrafiltration (UF) at the bench-scale and to compare EC with equivalent doses of ferric chloride. UF membrane performance was evaluated by transmembrane pressure (TMP) and hydraulic resistances at sub- and super-critical fluxes, and by flux recovery after hydraulic and chemical cleanings. Modified Atlantic Ocean seawater was used. Constant flux UF operation (50 to about 350 lmh) was used to evaluate short-term performance at sub- and super-critical fluxes, and constant feed-pressure (15 psi) experiments were used to investigate filter cake stability under high TMP conditions. In-line EC improved UF membrane performance for all coagulation and flux conditions. Compared to no coagulant pretreatment, ferric chloride improved UF membrane performance under short-term, constant flux conditions that resulted in TMP < 8 psi, but produced increased TMP and resistance to filtration at 15 psi. EC always resulted in lower resistance and improved flux recovery after cleaning compared to an equivalent dose of ferric chloride. Overall, EC is a feasible and competitive pretreatment strategy at the bench-scale, but scale-up issues, electrode cleaning requirements, and sustainability during long-term operation need further study.  相似文献   

18.
江爱朋  程文  姜周曙  林迎辉 《化工学报》2015,66(10):4092-4100
膜污染是导致反渗透海水淡化(seawater reverse osmosis,SWRO)系统操作成本增加和产水性能下降的重要因素。为了降低系统运行操作成本,本文针对卷式SWRO系统提出了一种新的膜清洗与更换策略优化方法。首先,根据反渗透和膜污染过程机理建立了膜污染情况下的SWRO系统性能模型;然后将生产过程中的总操作费用与膜清洗和更换规划联系起来,建立了以系统日均操作费用最低为目标、以膜清洗次数、膜清洗和更换时间等为寻优变量、以开放式方程模型为约束的优化命题,并通过联立求解等技术使得原本复杂的优化命题可快速方便地求解;在此基础上对SWRO系统进行了实例研究和分析。优化求解结果表明:(1)本优化策略可以大幅降低系统操作费用,并同时获得最佳膜清洗和更换时间以及膜清洗次数;(2)进料海水温度对最优膜清洗和更换策略影响很大,固定周期的膜更换策略并不合适。另外本优化方法还可得到不同条件下最优操作费用组成、以及最优目标下最优操作压力和操作流量曲线等信息,对优化SWRO系统运行和深入分析系统内部状态变化具有重要意义。  相似文献   

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