Membranes microfiltration

Cross Flow Most membrane processes are operated in cross flow, and only a few have the option to operate in the more conventional dead-end flow. In cross flow, the retentate passes parallel to the separating membrane, often at a velocity an order of magnitude higher than the velocity of the stream passing through the membrane. Microfiltration is the major membrane process in which a significant number if apphcations may be run with dead-end flow. 

There have been only a few studies have evaluated membrane microfiltration of secondary wastewater effluent. Microfiltration membranes might be used to achieve very low turbidy effluents with very little variance in treated water quality. Because bacteria and many other microorganisms are also removed, such membrane disinfection might avoid the need for chlorine and subsequent dechlorination. Metal... 

The solid-liquid separation of shinies containing particles below 10 pm is difficult by conventional filtration techniques. A conventional approach would be to use a slurry thickener in which the formation of a filter cake is restricted and the product is discharged continuously as concentrated slurry. Such filters use filter cloths as the filtration medium and are limited to concentrating particles above 5 xm in size. Dead end membrane microfiltration, in which the particle-containing fluid is pumped directly through a polymeric membrane, is used for the industrial clarification and sterilisation of liquids. Such process allows the removal of particles down to 0.1 xm or less, but is only suitable for feeds containing very low concentrations of particles as otherwise the membrane becomes too rapidly clogged.2,4,8... 

Economics Micronltration may be the triumph of the Lilliputians nonetheless, there are a few large-industrial applications. Dextrose plants are very large, and as membrane filtration displaces the precoat filters now standard in the industry, very large membrane microfiltration equipment will be built. 

Membrane microfiltration at the Palmerton Zinc Superfund site in Pennsylvania VOCs (liquid), metals, and oily, inorganic, organic wastes E.I. DuPont de Nemours and Oberlin Filter Company... 

Brandhuber and Amy (1998) and Shih (2005) provide concise summaries of arsenic removal with different types of membranes. Microfiltration and ultrafiltration are used to remove particles that contain sorbed, coprecipitated, or precipitated arsenic (US EPA, 2002b, 35 Shih, 2005, 93, 94). Both reverse osmosis and nanofiltration can effectively remove As(V) oxyanions from water and, in some cases, H3ASO3 can also be treated without preoxidation (Brandhuber and Amy, 1998, 9 Uddin et al., 2007a Xia et al., 2007 Uddin et al., 2007b). 

Davies, W.J., Le, M.S. and Heath, C.R. (1998) Intensified activated sludge process with submerged membrane microfiltration. Water Science and Technology, 38 (4-5), 421-428. 

Plasma separation by membrane microfiltration was proposed in 1978 by Salomon et al. [1] as a substitute to centrifugation and its clinical potential confirmed in 1980 by Samtleben et al. [2]. This technique yields a high-quality cell-free plasma that avoids for the recipient the immunological hazards of contamination by platelets and cellular fragments and is less traumatic for red cells, if precautions are taken to avoid hemolysis during filtration. 

Goudedranche H, Fauquant J, and Maubois J-L. Fractionation of globular milk fat by membrane microfiltration. Lait 2000 80 93-98. Brans G, Schroen CGPH, van der Sman RGM, and Boom RM. Membrane fractionation of milk state of the art and challenges. J. Membr. Sci. 2004 243 263-272. 

Nanosuspensions can be sterilized for parenteral use by using conventional steam sterilization in an autoclave, y-irradiation, or membrane microfiltration in certain situations. 

Kluge, T. Kalra, A. Belfort, G. Viscosity effects on Dean vortex membrane microfiltration. AIChE J. 1999, 45, 1913. 

Schutyser, M. Rupp, R. Wideman, J. Belfort, G. Dean vortex membrane microfiltration and diafiltration of rBDNF E.coli inclusion bodies. Biotechnol. Prog. 2002, 18, 322-329. 

Carver-Greenfield process for extraction of oily waste Chemtect gaseous waste treatment freeze separation membrane microfiltration... 

Zhao, Y. et al.. Effects of inorganic salt on ceramic membrane microfiltration of titanium dioxide suspensions.. 1. Membr. Sci., 254, 81, 2005. 

HiUis P. (1997), Full-Scale Application of Membrane Microfiltration in North West Water Huntington Stage 4, Provision of an 80 Mid Plant, Desalination, 113, 267-272. 

Ho B., Kumar P., Eslake J. (1995), Performance evaluation of membrane microfiltration plant at Kangaroo Valley, AWWA 16 Federal Convention, Vol 2, Sydney, Apr 95, 613-620. 

Patel R., Penisson A.C., Hill R.D., Wiesner M.R. (1994), Membrane microfiltration of secondaty wastewater effluent. Chemical Water and Wastewater Treatment III, 29-36. 

Nagata N, Herouvis KJ, Dziewulski DM et al. (1989) Cross-flow membrane microfiltration of a bacteriol fermentation broth. Biotechnol Bioeng 34(4) 447 66 Nagodawithana T (1992) Yeast-derived flavors and flavor enhancers and their probable mode of action. Food Technol 46 138-144... 

The associated disadvantages include (1) requirements for large quantities of nutrients (growth medium) relative to batch and fed batch modes of operation (2) high material costs associated with purchase and preparation/sterilization of the growth medium (3) elevated waste treatment costs and (4) fouling of the surfaces of permselective membranes or conventional or membrane microfiltration devices, which can lead to marked decreases in the flux of... 

Goudedranche H, Fauquant J, and Manbois J-L. Fractionation of globular milk fat by membrane microfiltration. Lait 2000 80 93-98. 

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