Mechanisms of chelate formation during organo-mineral melioration of heavy metals polluted acid soils (I)
2001
Raychev, T. | Arsova, A. | Popandova, S. (N. Poushkarov Institute of Soil Science, BG-1080 Sofia (Bulgaria)) | Jozefaciuk, G. | Sokolowska, Z. | Hajnos, M.
The study performs a theoretical discussion on the different mechanisms of chelate formation during organo-mineral liming of heavy metals polluted soils. According to the theoretical analysis of the relations among the different components in the chelate formation processes one can state that: the phenolic hydroxyl groups, amount of which is generally equal to this of the carboxyls in the molecules of highly humified organic compounds, buffer the relative excess of lime thus counteracting the effect of overliming; the relative deficiency of calcium ions preserves the participation of these groups in complex heteropolar salts, that indicates the dynamic character of the phenolic hydroxyls in the organo-mineral reactions; the depletion of the intra-molecular rearrangement reactions in the anionic part of the organic molecules can lead to the formation of organo-mineral adsorption complexes via polyvalent cationic bridges. The effect of this is a decrease of ion-exchange reactions between soil adsorbent and the plant root system.
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