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The effect of particle rotation on the motion and rejection of capsular particles in slit pores 下载免费PDF全文
Armin Delavari Basavaraju Agasanapura Ruth E. Baltus 《American Institute of Chemical Engineers》2018,64(7):2828-2836
The results from a two‐dimensional computational model describing the motion of capsule‐shaped particles in a slit pore under small Re conditions are reported. Average particle velocities and particle rejection coefficients were determined for capsules with aspect ratios of 2 and 4. Two different approaches were used to characterize particle rotation and hydrodynamic particle‐pore wall interactions. In one approach, all sterically allowed particle orientation angles had equal probability, i.e., infinite rotational diffusion was assumed. In the second approach, particles were allowed to freely rotate in the pore; particle orientations were dictated by hydrodynamic forces acting on the particle surface and rotational particle diffusion was neglected. Minimal lateral migration across the pore was observed for the freely rotating particles. Although particle alignment was observed for the freely rotating particles, rejections predicted from the two approaches were found to be in close agreement. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2828–2836, 2018 相似文献
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低压膜净水过程中的膜污染控制 总被引:1,自引:0,他引:1
近年来,低压膜(LPM)技术在饮用水处理和废水回用等领域的应用越来越广泛,但膜污染会消耗更多的能源,增加运行和维护费用,是制约其发展的瓶颈。膜前预处理技术与低压膜组合工艺已被广泛用在减轻膜污染、提高污染物去除率和膜通量等方面。膜前预处理技术可以改变水中分子与颗粒物的尺寸,影响污染物之间和污染物与膜之间的相互作用关系,抑制不良微生物的生长或去除可生物降解的污染物,从而影响膜过滤性能。此外,采用适当的操作方式(如运行方式,反冲洗,曝气)也可以有效地减轻膜污染。该文介绍了近年来国内外各种预处理技术和操作条件在控制低压膜污染的最新研究进展,并阐述了其在缓解膜污染方面的机理。 相似文献
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阐述了膜分离技术在化学工业过程中的部分应用,如用于合成氨中的氢气回收、有机蒸汽的分离回收、催化裂化中的富氧再生、海水淡化、卤水提炼及工业废水处理等工艺过程中,并对膜分离技术的强化和未来进行了展望。 相似文献
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通过考察膜分离过程中各操作条件对分离效果的影响,特别是低压操作条件下RO和强化UF膜分离过程中,添加剂种类和含量、重金属浓度、膜操作压力、反应时间对膜分离过程的截留率、渗透通量等的影响,为该技术的应用和推广提供理论支持。 相似文献
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纳滤膜技术在水处理中的应用 总被引:2,自引:0,他引:2
对纳滤膜的定义、特点、分离机理等作了介绍。综述了纳滤膜在工业废水处理、饮用水净化、水软化等方面的研究应用进展,并对纳滤膜分离技术的应用前景进行了展望。 相似文献
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饮用水的生物处理需要有效地除去水中阴离子微污染物。然而,在不改变水质和不增加新的污染物或除去水中必须元素的条件下,除去目标污染物的专门技术尚未成熟。一些新技术包括:压力推动膜生物反应器;气体传递膜生物反应器;离子交换膜生物反应器。这些技术综合了膜分离和微污染物离子的生物降解,可以有效地减少水的二次污染。 相似文献
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Membrane fouling seriously restricts applications of membrane technology. A novel strategy was ap-plied in this study to retard membrane fouling by changing operating pressure with the pressure responsibility membrane. A polyurethane-based hollow fiber membrane was used to treat surface water for evaluating the effect of operating pressure on membrane fouling. Some bench-scale tests in dead-end mode were carried out. In the experi-ments without backwashing, as operating pressure increased, severe membrane fouling occurred on membrane sur-face, while the permeate quality was improved obviously, which is considered to be due to shrinkage deformation. The total resistance, irreversible resistance and reversible resistance under different backwash pressures were de-termined in filtration/backwashing test. With the increase of backwash pressure, the total resistance decreased, and more importantly, the irreversible resistance also decreased, which implies that small particles deposited inside membrane pores and cake layers on membrane surface are effectively removed. Similar results could be obtained in mass balance tests. The results of the present study indicate that the application of pressure responsibility membrane in surface water treatment may be an effective strategy for reducing membrane fouling. 相似文献
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水处理中膜技术的应用与展望 总被引:2,自引:0,他引:2
介绍了膜分离技术的工作原理、特点和分类,阐述了膜分离技术在水处理中的应用,分析了目前存在的问题,并展望了膜技术应用领域的发展趋势。 相似文献
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综合介绍了膜技术在我国油田采出水处理中的应用,重点介绍了微滤、超滤和纳滤技术在油田采出水处理中的应用,并对油田采出水水质的特点和膜技术目前存在的不足进行介绍,对未来膜技术在油田采出水处理中的应用进行了展望。 相似文献