Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Formed-in-place membranes

Chiang, W.E., Cordle, C.T., and Thomas, R.L. 1995. Casein hydrolysate produced using a formed-in-place membrane reactor. J. Food Sci. 60, 1349-1352. [Pg.252]

Using a two-stage, single-pass module of food-grade dynamic metal oxide membrane on a sintered stainless steel support tube under a TMP of approximately 20 bars and a temperature of 50 C, Thomas et al. [1987] have successfully clarified apple puree with a juice yield of 86% and a steady state flux of about 85 L/hr-m. The quality of the clarified apple juice by this dynamic or formed-in-place membrane is excellent -sparkling looking and flavor retained. As much as 65% reduction in the total pectins has been attained. [Pg.201]

There are two different levels where fouling phenomena and related effects may interfere with performance of composite inorganic or hybrid membranes. The first and the more classically reported in literature is the one of the separation process itself, which through various interactions between solution and material (adsorption, surface deposits, pore plugging) generally leads to reduced fluxes and increased retentions. The second, much more less described by authors but of the same nature and with analogous effects, concerns membrane preparation, and the possible interactions between deposited layers. Theses two aspects are linked up with the so-called formed-in-place membranes, obtained by deposition of species onto a ceramic support through cross-flow filtration. In what follows, they will be described in a unified approach. [Pg.575]

Recently, Negrel et al. [18] proposed a new route to get nanofiltration performance starting from a formed-in-place membrane of gelatin deposited on a... [Pg.580]

Fig. 12.6, PEG rejection versus time for a formed in place membrane made of tanned gelatin [18]. Fig. 12.6, PEG rejection versus time for a formed in place membrane made of tanned gelatin [18].
Dynamic membrane This type of membrane structure, also referred to as formed-in-place membrane, can be produced in several different ways. A commonly used technique involves introducing solutions of organic or... [Pg.334]

According, to the developer, the formed-in-place membrane can be easily modified to conform to waste characteristics and the degree of contaminant removal desired. Therefore, the membrane can be tailored to the unique characteristics of the waste steam. [Pg.165]

Extensive data were collected on primary pollutants (phenols, and PAHs) and on secondary pollutants (oil, suspended and dissolved solids, COD, dioxins, and VOC s). The results of this project demonstrated the ability of the formed-in-place membrane, operating in a cross-flow mode, to minimize fouling, and to remove polynuclear aromatic hydrocarbons from the contaminated feed water. As operated, rejection of the PAHs appears to increase with the number of aromatic rings. However, similar correlations appear to exist with molecular weight as well as with the partition coefficient reflecting hydrophobicity. The permeate, accounting for approximately 80% of the feedwater, contained only about 12% of the predominant PAHs, naphthalene and phenanthrene. [Pg.165]

The ability to repeatedly regenerate the flux after the cleaning procedure is a good indication that the formed-in-place membrane is stable and can be used over an extended length of time. In the unlikely event of an irreversible fouling, the membrane can be cost-effectively and easily reformed on-site with a minimum of downtime. [Pg.166]

The technology uses a proprietary formed-in-place membrane technique. The membrane is formed on porous sintered stainless steel tubes by depositing microscopic layers of inorganic and polymeric chemicals. The properties of the formed-in-place membrane can be varied by controlling the type of membrane chemicals used, their thickness, and the number of layers. This important feature allows for customization of the membrane system to a wide variety of waste characteristics and clean-up criteria. The formed-in-place membrane can be quickly and economically reformulated in the field to accommodate changes in waste characteristics or treatment requirements. [Pg.166]

The formed-in-place membrane is compatible with a wide variety of contaminants often encountered in hazardous wastewater streams. The formed-in-place membrane is stable under most chemical environments and will not degrade even at high contaminant concentrations. [Pg.166]

The formed-in-place membrane is compatible with a wide variety of contaminants often encountered in hazardous wastewater steams. Many ccmventional reverse osmosis membranes are made from materials such as cellulose acetate and exhibit poor conqmtibility with reactive substances often encountered in hazardous wastes. These cmventiaial membranes will degrade and become inoperative when challenged with many organic cmnpounds. The compatibility problem becomes more critical as the level of concentration increases. The formed-in-place membrane is stable under most chemical environments and will not degrade even at high contaminant concentrations. [Pg.173]

Since all membranes eventually foul, a cleaning cycle is necessary to restore flux and operability. Many membrane systems have limited abilities to be regenerated due to restrictions in the chc ce of cleaning chemicals. Hie formed-in-place membrane is compatible with a wide rai e of chemical cleaning methods, enabling in-place regeneration of flux. In situatimis where the membrane becomes irreversibly fouled, the formed-in-place membrane can be stripped and reformulated on-site. [Pg.174]


See other pages where Formed-in-place membranes is mentioned: [Pg.948]    [Pg.570]    [Pg.580]    [Pg.614]    [Pg.164]    [Pg.166]    [Pg.169]    [Pg.173]    [Pg.178]    [Pg.181]    [Pg.194]    [Pg.194]   
See also in sourсe #XX -- [ Pg.580 ]




SEARCH



Membrane Form

Places

Placing

© 2024 chempedia.info