Inorganic species, sorption

The first section deals specifically with the spectroscopic/ microscopic tools that can be used in concert with macroscopic techniques. The second section emphasizes computer models that are used to elucidate surface mediated reaction mechanisms. The remainder of the volume is organized around reaction type. Sections are included on sorption/desorption of inorganic species sorption/desorption of organic species precipitation/dissolution processes heterogeneous electron transfer reactions photochemically driven reactions and microbially mediated reactions. What follows are a few highlights taken from the work presented in this volume. 

A technique for the determination of free cupric ions in seawater has been described by Sunda and Hanson [332], The method is based on sorption of copper onto Sep-Pak Cis cartridges and internal free cupric ion calibration. Calibration is accomplished by adding cupric ion buffers and EDTA, which competes with natural organic ligands for copper complexation. The method was used to establish that 0-2% of the copper occurs as inorganic species and 98-100% occurs as organic complexes. 

Biernat, J.F. Konieczka, P., and Izatt, R.M., Complexing and chelating agents immobilized on silica gel and related material and their application for sorption of inorganic species, Sep. Purif Methods, 23(2), 77-120 (1994). 

Griffin et al. (1977) showed the strong pH dependency of the sorption by kaolinite and montmorillonite of cationic (Pb, Cu, Hg, Cr +) and anionic (As, Se, Cr +) species of heavy metals present in different landfill leachates and inorganic solutions. Sorption of the former increased as pH increased, whereas the removal of the latter decreased as the pH was raised. The... 

Of the various inorganic soil constituents, smectites (montmorillonite clays) have the greatest potential for sorption of pesticides on account of their large surface area and abundance in soils. Weak base pesticides, both protonated and neutral species, have been shown to be sorbed as interlayer complexes. Sorption of atrazine on smectites ranges from 0 to 100% of added atrazine, depending on the surface charge density of the smectite (36). 

Aquatic sediments are formed in all surface waters by the settling of coarse and fine inorganic and organic particles. They are present in rivers, in lakes and in the oceans, and radionuclides deposited on the surface of the earth will sooner or later come into contact with these sediments. They may enter the sediments by sorption of molecularly-dispersed species (ions, molecules), by precipitation or coprecipitation, by coagulation of colloids (in particular carrier colloids) followed by sedimentation of the particles formed, or by sedimentation of coarse particles (suspended matter). By desorption, the radionuclides may be remobilized and released again into the water. 

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