Authors: Daniel ArenasLago Flora A Vega Luis Felipe O Silva María Luisa Andrade
Publish Date: 2014/06/03
Volume: 21, Issue: 18, Pages: 10997-11008
Abstract
The horizons of four natural soils were treated with Cu2+ in an acid medium to study the retention capacity of Cu The possible mineralogical changes arising because of the treatment were also studied The soil properties and characteristics with the greatest influence on the metal retention and its distribution among the different soil fractions were determined Crystalline phases of each horizon were determined by Xray diffraction XDR The morphology structural distribution and particle chemical composition of soil samples were investigated using field emission scanning electron microscopy Cu distribution in the different geochemical phases of the soil was studied using a sequential extraction The treatment led to an increase in the amorphous phases and the formation of new crystalline phases such as rouaite Cu2NO3OH3 and nitratine NaNO3 Cu was also found superficially sorbed on amorphous hydroxy compounds of Fe that interact with albite muscovite and gibbsite and also on spherical and curved particles of aluminium clays The largest amount of Cu retained was in an exchangeable form and the smallest amount associated with the crystalline Fe oxides and residual fraction In the surface horizons the predominant Cu retention process is complexation in organomineral associations while in the subsurface horizons it is adsorptionThis study was supported by the Xunta de Galicia project EM2013/018 We also thank the Spanish Ministry of Education and Science due to the Ramón y Cajal contract awarded to FA Vega D Arenas Lago was also awarded with a predoctoral fellowship FPIMICINN
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