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Increased zinc and copper availability in organic waste amended soil potentially involving distinct release mechanisms Полный текст
2016
Tella M. | Bravin M. | Thuriès L. | Cazevieille P. | Chevassus-Rosset C. | Collin B. | Chaurand P. | Legros S. | Doelsch E.
Increased zinc and copper availability in organic waste amended soil potentially involving distinct release mechanisms Полный текст
2016
Tella M. | Bravin M. | Thuriès L. | Cazevieille P. | Chevassus-Rosset C. | Collin B. | Chaurand P. | Legros S. | Doelsch E.
This study aimed at determining the fate of trace elements (TE) following soil organic waste (OW) application. We used a unique combination of X-ray absorption spectroscopy analyses, to determine TE speciation, with incubation experiments for in situ monitoring of TE availability patterns over a time course with the technique of the diffusive gradients in thin films (DGT). We showed that copper (Cu) and zinc (Zn) availability were both increased in OW-amended soil, but their release was controlled by distinct mechanisms. Zn speciation in OW was found to be dominated by an inorganic species, i.e. Zn sorbed on Fe oxides. Zn desorption from Fe oxides could explain the increase in Zn availability in OW-amended soil. Cu speciation in OW was dominated by organic species. Cu release through the mineralization of organic carbon from OW was responsible for the increase in Cu availability. (Résumé d'auteur)
Показать больше [+] Меньше [-]Increased zinc and copper availability in organic waste amended soil potentially involving distinct release mechanisms Полный текст
2016
Tella, Marie | Bravin, Matthieu N. | Thuriès, Laurent | Cazevieille, Patrick | Chevassus-Rosset, Claire | Collin, Blanche | Chaurand, Perrine | Legros, Samuel | Doelsch, Emmanuel
This study aimed at determining the fate of trace elements (TE) following soil organic waste (OW) application. We used a unique combination of X-ray absorption spectroscopy analyses, to determine TE speciation, with incubation experiments for in situ monitoring of TE availability patterns over a time course with the technique of the diffusive gradients in thin films (DGT). We showed that copper (Cu) and zinc (Zn) availability were both increased in OW-amended soil, but their release was controlled by distinct mechanisms. Zn speciation in OW was found to be dominated by an inorganic species, i.e. Zn sorbed on Fe oxides. Zn desorption from Fe oxides could explain the increase in Zn availability in OW-amended soil. Cu speciation in OW was dominated by organic species. Cu release through the mineralization of organic carbon from OW was responsible for the increase in Cu availability.
Показать больше [+] Меньше [-]Increased zinc and copper availability in organic waste amended soil potentially involving distinct release mechanisms
Impacts of land uses on mercury retention in long-time cultivated soils, Brazilian Amazon Полный текст
2013
Comte I. | Lucotte M. | Davidson R. | Reis de Carvalho C. | de Assis Oliveira F. | Rousseau G.X.
Many studies have shown the relationship between fire clearing and mercury contamination of aquatic ecosystems in the Brazilian Amazon. This study aimed at quantifying mercury content in long-time cultivated soils and at assessing the potential of a fire-free alternative clearing technique on mercury retention for long-time cultivated soils compared to traditional slash-and-burn. This case study included five land uses: one crop plot and one pasture plot cleared using slash-and-burn, one crop plot and one pasture plot cleared using chop-and-mulch, and one 40-year-old forest as a control. Low mercury concentrations were recorded in the surface horizon (24.83 to 49.48 ng g?1, 0–5 cm depth). The long-time cultivation (repeated burnings) of these soils triggered large mercury losses in the surface horizon, highlighted by high enrichment factors from surface to deeper horizons. The predominant effect of repeated burnings before the experimental implementation did not let us to distinguish a positive effect of the chop-and-mulch clearing method on soil mercury retention for crops and pastures. Moreover, some processes related to the presence of the mulch may favor mercury retention (Hg volatilization decrease, cationic sites increase), while others may contribute to mercury losses (cationic competition and dislocation, mobilization by the dissolved organic matter). (Résumé d'auteur)
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