Transfer between Inorganic and Organic Substrates

Metal Transfer between Inorganic and Organic Substrates 

With respect to the modeling metal partitioning between dissolved and particulate phases in a natural system, e.g. for estuarine sediments, the following reqirements have been listed by Luoma Davis (1983)  

It seems that models are still restricted because of various reasons (i) adsorption characteristics are related not only to the system conditions (i.e., solid types, concentrations and adsorbing species), but also to changes in the net system surface properties resulting from particle/particle interactions such as coagulation (ii) influences of organic ligands in the aqueous phase can rarely be predicted as yet (iii) effects of competition between various sorption sites, and (iv) reaction kinetics of the individual constituents cannot be evaluated in a mixture of sedimentary components. 

At present, experimental studies on the dissolved/solid interactions in such complex systems seem to be more promising. One approach is with a a six-chamber device, where the individual components are separated by membranes, which still permit phase interactions via solute transport of the elements (Calmano et al., 1988) in this way, exchange reactions and biological uptake can be studied for individual phases under the influence of pH, redox, ionic strength, solid and solute concentration, and other parameters  

The dominant role of organic substrates in the binding of metals such as Cd and Cu is of particular relevance for the transfer of these elements into biological systems. It can be expected that even at relatively small percentages of organic substrates these materials are primarily involved in metabolic processes and thus may constitute the major carriers by which metals are transferred within the food chain. 

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References to 5.3 "Metal Transfer between Inorganic and Organic Substrates"... 

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