共查询到19条相似文献,搜索用时 78 毫秒
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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
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根据内压式超滤膜和外压式超滤膜组件在冶金污水回用处理工程中的实际应用,从运行参数、出水水质、清洗周期等方面对两者进行了综合分析比较,同时分析了超滤膜污染的成因、工艺优化采取的措施。结果表明,外压式超滤膜跨膜压差的稳定性和产水透过率优于内压式超滤膜,2种膜的产水水质接近,外压式超滤膜的化学清洗周期是内压式超滤膜的3倍,外压式超滤膜更适用于大流量冶金污水反渗透脱盐的预处理。 相似文献
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水污染和水资源短缺已成为制约社会进步和经济发展的世界性问题,海水淡化是解决全球水资源短缺的重要战略手段之一,有着广阔的开发前景。海水淡化处理是一项系统工程,工程环节具有多样化特征,淡化过程中需要选择先进合理的组合工艺进行预处理,便于降低海水淤塞指数SDI和浊度等相关指标,有效提供优质稳定的进水,为反渗透长期、安全、稳定运行提供坚实保障。本文就海水淡化预处理工艺中国产超滤膜的应用情况进行分析,积极推动国产超滤膜性能优化,提升超滤膜产水量,满足新时期海水淡化系统设计运行的需要。 相似文献
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超滤在反渗透预处理工艺中的应用 总被引:7,自引:0,他引:7
以UF替代传统的预处理工艺,解决了RO制水系统预处理难的问题。试验结果表明:UF可把原水的SDI(或FI)指数由8-10降至接近于零,对水中的悬浮物,金属氧化物,胶体,有机物,菌类都有良好的去除效果,可完全满足RO系统对预处理水质的要求。本文重点讨论UF作为RO预处理的工艺;UF对水中杂质的脱除效果及运行性;UF膜通量的衰减规律及恢复。 相似文献
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反渗透海水淡化法中膜组件的定期清洗是防治膜污染的主要措施之一.膜清洗可将膜表面的污染物去除,达到恢复透水量的目的.在保证产水量的情况下,选择恰当的清洗策略和清洗时机可使清洗次数最合理,清洗费用最低.以规划期内总操作费用最小为目标,提出了新的污染模型,给出了清洗的判据,将清洗策略问题表达为一个混合整数非线性规划(MINLP).对一个实例进行计算,给出了该例中的反渗透系统在5年规划期内的最优清洗策略和清洗时机.结果证明这种数学规划方法对于寿命为3~5年的膜组件的清洗维护是有效的. 相似文献
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海水反渗透淡化技术的分析与探讨 总被引:1,自引:0,他引:1
反渗透海水淡化技术是一种高效、节能、先进的液体分离技术.论述了目前国内外海水反渗透淡化技术的应用现状,着重介绍了反渗透膜材料及特点、膜污染及清洗、典型的海水反渗透淡化流程,探讨了反渗透海水淡化技术目前存在的问题及未来发展趋势. 相似文献
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The presently used hollow fiber membrane modules consist of a bundle of fibers in a cylindrical polymer or metal shell parallel to the shell axis. The feed solution flows either through the lumen or at the outside parallel to the fibers. This paper compares the performance of these modules with a new transverse flow module where the hollow fibers are positioned perpendicularly to the flow direction. For both types of modules the product costs are calculated for desalination by reverse osmosis and Dextran concentration by ultrafiltration. These calculations are based on literature data. The main conclusion is that the application of the tr‘ansverse flow module is only attractive if the permeation resistance is mainly determined by the hydrodynamics (ultrafiltration) and not attractive if the membrane permeability is the main resistance (reverse osmosis). 相似文献
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Forward-osmosis strategy and chemical cleaning of seawater desalination reverse osmosis membranes 下载免费PDF全文
In order to settle the membrane fouling of reverse osmosis membranes in seawater desalination process, this study reported a novel strategy based on forward-osmosis process and discussed the effects of different factors like different cleaning combination among reverse osmosis product, simulated reverse osmosis concentrate and simulated seawater, as well as cleaning time on the membrane permeate flux and salt rejection. For irreversible fouling, the effects of different chemical cleaning agents, immersion time and concentration were also investigated in this study. The results exhibited that the cleaning combination between diluted water and simulated reverse osmosis concentrate possessed the best cleaning performance in the process of forward-osmosis cleaning. Such approach also enhanced normalized flux from 9.48 L/(m2·h·MPa) to 13.6 L/(m2·h·MPa) and enhanced NaCl rejection from 80.59% to 92.80%. Furthermore, the normalized flux was enhanced from 9.48 L/(m2·h·MPa) to 14.3 L/(m2·h·MPa) and NaCl rejection was also enhanced from 80.59% to 96.27% after soaking in 2%(mass) citric acid solution for 2h, soaking with 1%(mass) ethylenediamine tetra-acetic acid tetrasodium salt and 0.3%(mass) sodium tripolyphosphate solution for 1.5 h. According to the result of SEM images and AFM images, the forward-osmosis cleaning strategy could not cause the damage of selective layer of membrane surface and caused the drop of inorganic and organic fouling on the membrane surface. Hence, cleaning fouled RO membranes by such approach could prolong the chemical cleaning cycle and reduce the amount of chemical cleaning agent, which has certain industrial application perspectives. 相似文献
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为解决海水淡化过程中反渗透膜的污染问题,研究了基于正渗透策略的反渗透产水、模拟反渗透浓水、模拟海水不同的组合清洗和清洗时间对膜通量和截留率的影响。针对不可逆污染,研究了不同化学清洗药剂、浸泡时间、浓度对膜通量和截留率的影响。结果表明,正渗透策略清洗方式中,淡水/模拟反渗透浓水的组合清洗方式效果最佳,其归一化通量从9.48 L/(m2·h·MPa)提升至13.6 L/(m2·h·MPa),截留率从80.59%提升至92.80%。此外,经质量分数为2%的柠檬酸溶液浸泡2 h后,再使用质量分数为1%的乙二胺四乙酸四钠盐和0.3%的三聚磷酸钠溶液浸泡1.5 h,其归一化通量从9.48 L/(m2·h·MPa)提升至14.3 L/(m2·h·MPa),截留率从80.59%提升至96.27%。从SEM和AFM图可以看出,正渗透清洗策略并未对膜表面选择层造成损坏,且可以清洗膜表面的有机污染物和无机污染物,因此,应用这种方法对污染的反渗透膜进行清洗,可延长化学清洗周期,减少化学清洗剂用量,具有一定的工业应用前景。 相似文献
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