Silica particle sorbed water

The amount of DDT sorbed by clay was greater than that of heptachlor and dieldrin (Versar, 1979). Since the K c for DDT is 2.38 X 10 (Kenaga and Goring, 1980), sorption to particulate matter and eventual sedimentation seems to be an important pathway in the dynamics of DDT in the aquatic environment. The reported K values for the sorption of dieldrin to humic acid, soil, and silica sands are 228,1.6 X 10, and 2-5 (Weil et aL, 1973). It seems that soil-derived suspended particles in water will have appreciable affinity for dieldrin. The low coefficients for sands are not unexpected considering their lack of organic content. 

Natural colloid particles in aqueous systems, such as clay particles, silica, etc. may serve as carriers of ionic species that are being sorbed on the particulates (pseudocolloids). It seems evident that the formation and transport properties of plutonium pseudocolloids can not yet be described in quantitative terms or be well predicted. This is an important area for further studies, since the pseudocolloidal transport might be the dominating plutonium migration mechanism in many environmental waters. 

The bioactivity of silica is attributed to the nanodimensionality of its primary particles, to the presence of surface coordination compounds of water molecules, hydroxylated silicon atoms and strongly sorbed/highly structured bioactive water. Biologically active water (BAW) is a special form of water whose molecules are strongly bound to the BAS surface but at the same time are weakly associated. BAW is formed within gaps among biologic objects and particles of amorphous nanodimensional silica at a certain water content, spatial structure, and hydrophobic-hydrophilic balance at interfaces.10... 

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