Clay, adsorption properties

A method [62] has been described for the determination of down to 2.5pg kg-1 alkylmercury compounds and inorganic mercury in river sediments. This method uses steam distillation to separate methylmercury in the distillate and inorganic mercury in the residue. The methylmercury is then determined by flameless atomic absorption spectrophotometry and the inorganic mercury by the same technique after wet digestion with nitric acid and potassium permanganate [63]. The well known adsorptive properties of clays for alkylmercury compounds does not cause a problem in the above method. The presence of humic acid in the sediment did not depress the recovery of alkylmercury compounds by more than 20%. In the presence of metallic sulphides in the sediment sample the recovery of alkylmercury compounds decreased when more than lmg of sulphur was present in the distillate. The addition of 4M hydrochloric acid, instead of 2M hydrochloric acid before distillation completely, eliminated this effect giving a recovery of 90-100%. 

Borggaard, O.K. (1983) Effect of surface area and mineralogy of iron oxides on their surface charge and anion-adsorption properties. Clays Clay Min. 31 230-232 Borggaard, O.K. (1983 a) The influence of iron oxides on phosphate adsorption by soil. J. 

The concept zeolites conventionally served as the synonym for aluminosilicates with microporous host lattice structures. Upon removal of the guest water, zeolites demonstrate adsorptive property at the molecular level as a result they are also referred to as molecular sieves. Crystalline zeosils, AlPO s, SAPO s, MAPO s (M=metal), expanded clay minerals and Werner compounds are also able to adsorb molecules vitally on reproval of any of the guest species they occlude and play an Important role in fields such as separation and catalysis (ref. 1). Inclusion compounds are another kind of crystalline materials with open framework structures. The guest molecules in an inclusion compound are believed to be indispensable to sustaining the framework structure their removal from the host lattice usually results in collapse of the host into a more compact crystal structure or even into an amorphous structure. 

General. The abyssal red clays were, in part, originally selected for study because previous investigations of their sorption properties had been encouraging (6,7), and because generally the types of minerals occurring in the sediment exhibit very favorable ion-exchange and adsorption properties. In... 

Purification of the clay did not seem to have a marked effect on adsorptive properties. In this connection, it should be mentioned that in bringing the sample to a controlled ionic form before measurement, alkaline earth carbonates, if present, were probably removed, because the operation usually involved equilibration at pH 5. However, oxidation to remove organic matter and treatment with complexing agents to remove iron oxides apparently had little effect. 

Besides using the EPR to evaluate the binding capacity of NOM for metal ions, it is also possible to use the latter as spin probe (Senesi, 1990a). Analyses of spectroscopic data comprise studying the adsorptive properties, surface interactions, and structural chemistry of soil, synthetic metal oxides, hydrous oxides, and clay minerals (McBride et al., 1984 Coyne and Banin, 1986 Senesi et al., 1991a Spagnuolo et al., 2004). 

VII. Other Sorbents and Their Unique Adsorption Properties Carbon Nanotubes, Heteropoly Compounds, and Pillared Clays 118... 

In this regard, as a result of their adsorption properties, MMS and PILCs could be convenient materials for hydrogen storage. But, there are very few reports on hydrogen adsorption in MMS [156] and pillared clays [9,157],... 

Browne JE, Feldkamp JR, White JL, Hem SL. Characterization and adsorptive properties of pharmaceutical grade clays. / Pharm Sd. 1980 69(7) 816-823. 

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