High-energy sites

Ca-Rb equilibria. The increasing number of high energy sites (table VI) is associated with the formation of collapsed (10 A) illite layers, which were observed (102-104) with increasing number of H.D. cycles. 

Hydrophobic interactions took place on the low-energy sites (alkyl chains) and ion-exchange interactions on the high-energy sites (most likely, acidic silanols buried under the alkyl layer). 

Adsorption by activated carbon is commonly employed for the removal of TNT from aq waste streams, eg, pink water formed in shell-loading operations. Low efficiency in regeneration of the carbon for reuse has led to a study of the factors involved (Ref 99), with conclusions as follows. The TNT is adsorbed at many of the numerous high-energy sites on the surface of the carbon. Basic materials, introduced during activation of the carbon by combustion and oxidation and also present at these sites, then induce oxidation-reduction reactions of the methyl with the nitro groups in the TNT. This is... 

The cause of the concentration dependence is not known. Using the data from 62 isotherms from the above references, there is no correlation between 1In for atrazine sorption and organic carbon content, clay content, or pH. It appears the heterogeneity of soils results in a continuum of sorption sites with differing amounts of low- and high-energy sites in different soils. 

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