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以N-甲基二乙醇胺(MDEA)溶液为吸收液,采用膜吸收法进行了模拟天然气脱硫试验,考察了不同膜参数对MDEA溶液脱硫过程中传质性能的影响。结果表明:在较为理想的稳态膜吸收过程中,多孔膜孔径大小、膜厚度以及膜孔形态等因素对稳态膜吸收过程中的传质效果影响不大;在其他条件不变的情况下,多孔膜的传质性能随着孔隙率的增大而提高;同时传质效果还受到膜润湿现象的影响。这说明在较为理想的稳态膜吸收过程中孔隙率是对传质效果产生影响的主要因素,为膜吸收过程传质的影响因素探究及多孔膜选择提供了依据。 相似文献
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膜分离技术由于具有优越的分离性能,较小的占地面积和低廉的成本,在废水处理领域具有较好的应用前景。然而,膜污染是制约膜分离技术进一步推广的决定性因素。回顾了近年来有关膜污染控制技术的研究成果,包括错流过滤、脉冲进料,多级膜组合工艺,特别是膜的表面改性方面的研究。提出了一些可行的抗污染策略,如将电泳电渗技术与膜分离工艺结合,可大大提高膜的抗污染性能。该文展望了材料改性方面的最新技术,采用仿生改性,如模仿细胞膜、多巴胺等结构和组分进行改性,制备的膜可以极大延迟膜的报废时限、延长膜的运行周期,是实现高效抗污染分离膜的有效措施和膜材料改良的最理想途径。总之,膜的改性应建立在充分了解膜污染机理和膜界面动力学的基础上,膜改性的成功与否,材料的选择至关重要。 相似文献
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引起膜污染的因素主要有污泥特性、运行参数、膜材料和进水特性。尽管国内外学者对膜污染进行了大量的研究,但对其影响因素仍然感到非常困惑,主要是因为膜污染物和活性污泥特性异常复杂。膜污染现象增加污水处理运行和维修费用,是限制膜生物反应器(MBR)在污水治理方面广泛应用的主要障碍,其中微生物代谢产物(EPS、SMP)是引起膜污染的主要物质。在论述了溶解性代谢产物(SMP)对膜污染影响的基础上,着重从减少SMP的角度介绍了缓解膜污染的控制措施。 相似文献
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采用溶胶-凝胶方法制备光催化性能优良的TiO2纳米膜,应用X射线衍射仪分析了TiO2纳米膜的结构,探讨了铁离子和贵金属Ag、Pt掺杂对TiO2纳米膜光催化降解性能的影响,研究了TiO2纳米膜及掺杂改性TiO2纳米膜对生物二级处理系统出水中有机物光催化去除的性能。贵金属Ag、Pt掺杂提高了TiO2纳米膜光催化性能,而铁离子掺杂则降低了其催化性能。未掺杂的TiO2纳米膜使二级出水的COD下降8.9%,而贵金属Ag、Pt掺杂的TiO2纳米膜则使COD分别下降19.4%和22.3%。实验结果表明TiO2纳米膜有优良的光催化降解性能,TiO2纳米膜有广阔的应用前景。 相似文献
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在新兴环保领域,膜蒸馏(MD)技术经最近10年研究的不断拓展、深入,产业链逐渐形成。瞄准膜蒸馏技术涉及的疏水膜、膜组件、工艺与应用3个重要方面,概述了膜蒸馏技术的最近10年研究现状及发展方向。从疏水膜制备的角度,重点探讨了兼具高通量、高强度、抗润湿及抗污染等特点的疏水膜制备方法;从膜蒸馏组件设计角度,重点探讨了结构形式优化、内/外场辅助等过程强化手段及具有稳定、高效、低耗传质特点的膜组件设计方法;从工艺与应用角度,概述了典型膜蒸馏集成工艺、清洁生产工艺及应用场景与国内外产业化现状。 相似文献
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膜生物反应器运行中的膜污染问题 总被引:9,自引:0,他引:9
这了各国研究者针对膜生物反应器中的膜污染问题所作的工作,认为膜本身的性质以及废水组成和工艺条件都是造成膜污染的主要原因,利用反冲洗和清洗手段,可以有效地改善膜的性能,以提高膜的寿命,膜生物反应器技术的改进是避免膜污染的新思路。 相似文献
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Alpha-tocopherol supplementation on chromium toxicity: a study on rat liver and kidney cell membrane 总被引:3,自引:0,他引:3
Membrane damage is one of the important consequence of chromium,an environmental toxicant,to produce cytotoxicity.α-tocopherol,a membrane protectant can be used to reduce the chromium-induced membrane damage.In the present study,the impact of chromium in presence and absence of α-tocopherol was studied on plasma membrane of live and kidney in male Wistar rats(80-100g body weight).Significant increase in membrane cholesterol level as well as significant decrease in membrane phospholipid level in chromium exposed(0.8mg/100g body weight/d,i.p.,for 4 weeks)animals suggest structural alteration of both liver and kidney plasma memebrane.The alkaline phosphatase,total ATPase and Na^ -K^ -ATPase activities of plasma membrane were significantly decreased in both liver and kidney after chromium treatment.However,α-tocopherol (30mg/100g diet)supplementation can restrict the changes in these membrane-bound enzyme activities.Thus,the usefulness of dietary supplementation of α-tocopherol to restrain the chromium-induced membrane damage is suggested. 相似文献
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电驱动膜分离将电化学与膜分离技术有机结合,通过调控电场或电极电位强化膜分离效果,有望突破膜污染、选择性分离弱及“trade-off”效应等技术瓶颈,是实现污/废水资源化的有效途径。提出电驱动膜分离概念,将电驱动膜分离分为电控膜分离、电渗析和膜电容去离子等技术类型,重点关注选择性膜分离回收废水中有价物质进而实现废水资源化。首先介绍了电驱动膜分离技术的基础研究进展,然后从膜/电极材料创新和工艺优化等角度对电控膜分离、电渗析和膜电容去离子的研究进展进行回顾和总结,最后从基础研究、材料创新和反应器开发3个方面对该技术未来的发展方向做出展望。 相似文献
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IntroductionInrecentyears,thetechniqueforultrafiltrationhasgainedrapiddevelopment.Moreandmorekindsofmembranesarestudiedandmanufactured ,andalarge scaleindustrialapplicationhasbeengrown .PANpolymerisextensivelyusedtoprepareUFmembranes(Stoiko,1 991 ) .Itshydrop… 相似文献
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The effect of coupling coagulation and flocculation with membrane filtration in water treatment: A review 总被引:4,自引:0,他引:4
TorOve Leiknes 《环境科学学报(英文版)》2009,21(1):8-12
Water supply and sanitation demands are foreseen to face enormous challenges over the coming decades to meet the fast growing needs in a global perspective. Significant growth in the industry is predicted and membrane separation technologies have been identified as one of the possible solutions to meet future demands. Application and implementation of membrane technology is expected both in production of potable water as well as in treatment of wastewater. In potable water production membranes are substituting conventional separation technologies due the superior performance, potential for less chemical use and sludge production, as well as the potential to fulfill hygienic barrier requirements. Membrane Bio-Reactor (MBR) technology is probably the membrane process which has had most success and has the best prospects for the future in wastewater treatment. Trends and developments indicate that this technology is becoming accepted and is rapidly becoming the best available technology (BAT) for many wastewater treatment applications. A major drawback of MBR systems is membrane fouling. Studies have shown that fouling mitigation in MBR systems can potentially be done by coupling coagulation and flocculation to the process. 相似文献