Filtration streaming potential

Streaming potential as a function of the apphed pressure for different membranes is shown in Figure 9.5. Trans-membrane or filtration streaming potential (FSP) for composite HR95 membrane, its porous support (membrane PS-Uf) and the DEAE-dextran fouled PS-Uf porous membrane is shown in Figure 9.5, where different effects of interest can be observed, depending on the membrane structure and solution ... 

Figure 9.5 (a) Transmembrane (filtration) streaming potential vs applied pressure ... 

The Fig. 1 shows the scheme of S.P.I.R.E. In the case of cross membrane streaming potential determination, the electrical potential is measured between the retentate and permeate membrane sides and is named filtration potential . Along the membrane, it is measured, without permeation, between the inlet and the outlet of the module. 

In practice, the cross membrane filtration potential is modified by a very brief jump of transmembrane pressure and, in consequence, of the permeate rate, which creates a jump of filtration potential, too (Fig. 2). For a given pH, that procedure is repeated with different pressure jump values. The streaming potential is obtained by dividing filtration potential jump value by transmembrane pressure jump value. The same test done at different pH, enables to determine the isoelectric point of a membrane (Fig. 3) and to have an idea on electrostatic charges density and sign. 

Characterization of membranes used in filtration processes (microfiltration, ultrafiltration, nanofiltration, reverse osmosis) is usually carried out by hydro-dynamic measurements (hydraulic permeability, retention) [5-10], but electrical measurements such as streaming potential (SP or electroosmotic flow) and membrane potential (MP) are used for characterizing, respectively, the mem-brane/solution interface (zeta potential, surface charge density) and the effective membrane fixed charge and ion transport numbers in the membrane [11-27]. Moreover, great and rapid development of membranes for fuel cells... 

These filters are well proven for removing particulates in a variety of systems but have not previously been used in biomass gasification systems. For gasification systems these filters require hot product gas to be cooled prior to filtration. For that reason, they are most appropriate for applications where retaining the sensible heat of the product gas is not critical. In addition, the presence of tars in the product gas can cause potential problems since tar condensation on the filter cake or the filter itself can lead to plugging. Care must be taken to ensure either that tars are removed from the stream prior to the bag filter or that the temperature remains high enough to prevent tar condensation. 

CMR over other catalyst retention techniques is its potentially infinitely high partition coefficient between the retentate, the retained phase in the reactor, and the filtrate, the stream leaving the CMR retention by phase change such as precipitation or extraction can never achieve such partition coefficients. 

The mercury contamination of significant amounts of mustard agent stockpiled at TOCDF is another factor influencing potential carbon disposition. TOCDF is implementing a pollution abatement system filtration system (PFS) that will trap mercury on carbon. The resulting secondary waste stream consisting of carbon with adsorbed mercury will present a unique disposal problem.14... 

There are two other types of technologies—reverse osmosis (RO) and electrodeionization (EDI)—that remove dissolved solids from a liquid stream. Both are widely used in the water purification industry and have potential for use in the treatment of CMP wastewater. RO is a method by which water is forced through a semipermeable membrane that does not allow ions to cross. EDI removes ions from a liquid stream by means of an applied voltage. Both the EDI or RO are very effective in removing anions and cations, but the tradeoff is that the feed to the EDI or RO must be preconditioned to prevent damage to the equipment. In particular, the feedwater to an RO should not have a silt density index (SDI) greater than 3.0, which may require additional filtration to ensure all the solids are removed from the liquid stream. Some EDI manufacturers recommend that the feedwater to the EDI be RO permeate or of better quality. 

Finding 4-1. The documentation for secondaiy waste streams made available to the coimnittee failed to identify reverse osmosis rejectate brine, supercritical water oxidation (SCWO) filtrate solid waste, SCWO titanium tank liners, venturi scrubber particulate filters, or filters from the energetics offgas treatment system (OTE) as potential secondary wastes from BGCAPP. 

Pressure gradient Filtration Particle oscillations Streaming current and potential Colloid vibration potential... 

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