Interactions of EDDS with Fe- and Al-(hydr)oxides.
The efficiency of EDDS ([S,S]-ethylenediaminedisuccinate) in metal (phyto) extraction has been discussed in many recent papers. This study demonstrated that the presence of Fe- and Al-(hydr)oxides in soils influences the speciation of EDDS and thus can decrease the extraction of the targeted metallic contaminants (e.g., Pb, Cu, Zn). Above all, amorphous and poorly crystalline oxides (e.g., ferrihydrite) seem to significantly control dissolved Fe and Al concentrations in soils in the presence of metal-EDDS complexes and especially uncomplexed EDDS. Metals released from these minerals compete for the chelating agent and the extraction efficiency of the targeted metals is lowered. The formation of stable Cu-EDDS complexes, which are preferentially formed in soils with high Cu concentrations, results into a lower dissolution of ferrihydrite and goethite compared to free EDDS and Al-EDDS. Information about the contents of amorphous and poorly crystalline oxides in the treated soils would thus be beneficial for choosing efficient EDDS dosages.
Komárek
Michael
M
Department of Agro-Environmental Chemistry and Plant Nutrition, Czech University of Life Sciences Prague, Czech Republic. komarek@af.czu.cz
Vanek
Ales
A
Száková
Jirina
J
Balík
Jirí
J
Chrastný
Vladislav
V
D000536:Aluminum Hydroxide / Q000737:chemistry*; D002614:Chelating Agents / Q000737:chemistry*; D005029:Ethylenediamines / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D058085:Iron Compounds / Q000737:chemistry*; D008903:Minerals / Q000737:chemistry; D012987:Soil; D013386:Succinates / Q000737:chemistry*; D014961:X-Ray Diffraction
D002614:Chelating Agents; D005029:Ethylenediamines; D005290:Ferric Compounds; D058085:Iron Compounds; D008903:Minerals; D012987:Soil; D013386:Succinates; C094886:goethite; C041447:N,N'-ethylenediamine disuccinic acid; D000536:Aluminum Hydroxide; C092844:ferric oxyhydroxide