Adsorption material

J.K. Nprskov, Physics and Chemistry of Alkali Metal Adsorption, Material Science Monographs, H.P. Bonzel, A.M. Bradshaw, and G. Ertl, eds., Elsevier (1989). 

Keywords DNA Adsorption Materials Graphite Carbon Composite Nanotube Electrochemical sensing... 

Among the different adsorptive materials that have conventionally been used to capture metal ions from solution are activated charcoal (2), zeolites (3, 4), and clays (5). 

Adsorption pumps (see Fig. 2.59) work according to the principle of the physical adsorption of gases at the surface of molecular sieves or other adsorption materials (e.g. activated AljOj). Zeolite 13X is frequently used as an adsorption material. This alkali aluminosilicate possesses for a mass of the material an extraordinarily large surface area, about 1000 m /g of solid substance. Correspondingly, its ability to take up gas is considerable. 

BASIC PRINCIPLES OF ADSORPTION AND ION EXCHANGE 4.1.1 Adsorption materials... 

Spent ion-exchange and adsorption materials represent a special type of waste, and pose unique problems in the selection of their treatment options. With the evolution of environmental legislation, it is now required that spent materials meet specific quality requirements prior to disposal. In the selection of the treatment method for spent materials, their physical and chemical characteristics must be considered. Basically, there are two main treatment methods destruction and immobilization. In several occasions, depending on the nature of the spent material, a pretreatment step is required. 

In 2002, an interesting concept was proposed for coupling a C02-based supercritical extraction with air oxidation in order to remove and decompose pollutants from gases or liquids (134). An exemplary process scheme according to this preliminary concept is shown in Figure 5. Possible (future) environmental applications of such an integrated supercritical extraction-reaction system include treatment of liquid effluents, regeneration of catalysts and adsorption materials, and soil decontamination. 

To overcome problems with VX, a reaction with silver fluoride impregnated on a filter in front of the adsorption tube has been applied. The fluoride converts VX to the more volatile ethyl methylphos-phonofluoridate (CAS 673-97-2), which is more amenable to GC (37). In an alternative approach, adsorption tubes can be extracted with a suitable solvent such as ethyl acetate or acetone (chlorinated solvents may dissolve the polymeric adsorption material). This offers the advantage of a repeat analysis. To compensate for the loss of sensitivity, compared with thermodesorption, on-column... 

Adsorptive materials have been used for many years for the purification of chemicals. These materials include carbons, clays, and synthetic aluminosilicates. The disposal or regeneration of spent adsorbent is usually expensive, and generally viewed as a costly inconvenience. 

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