SharePoint
Aide
IRSN, Institut de radioprotection et de sûreté nucléaire

Search our site :

ok

Contact us :

ok
En Fr

Enhancing Nuclear Safety


Research

Publications

Fe, Al and Si species and organic matter leached off a ferrallitic and podzolic soil system from Central Amazonia


Journal title : Geoderma
Volume : 137
Issue : 3-4
Pagination : 444-454
Publication date : 15/01/2007

Summary

The geochemistry of soil formation in central Amazonia, Brasil, was investigated by studying the waters draining off small podzolic, ferrallitic or mixed catchment areas. Dissolved, colloidal and particulate fractions were obtained by cascade filtration and tangential-flow filtration. The organic carbon, Fe, Si, Al concentrations and the complexing capacity with regard to Cu2+ were determined for each fraction. In the waters draining podzolic areas, bulk concentrations were in the range 25.0-38.1 mg L- 1 for organic carbon, 240-280 μg L- 1 for Fe, 130-630   µg L- 1 for Al and around 0.9 mg L- 1 for Si. Fe mainly migrates as organo-metallic complexes, while Al migrates roughly half as inorganics in the particulate fraction and half as small species likely inorganic in the dissolved fraction. The result is the leaching of all elements and the relative accumulation of residual quartz. In the waters draining ferrallitic areas, bulk concentrations were in the range 1.2-1.9 mg L- 1 for organic carbon, 45-55   µg L- 1 for Fe, 106-220   µg L- 1 for Al and around 1.9 mg L- 1 for Si, this later concentration remaining below saturation with quartz. Most elements were transported in the dissolved fraction, except 10% of Si which was in the particulate fraction, likely as quartz, and 40-45% of Al which was in the colloidal fractions, likely as Al-hydroxides. The result is a relative enrichment of the soil in Si with regard to Al. The soils strongly control the physico-chemical characteristics of the forest stream waters, and their transport capacity with regard to complexable metals. Moreover, our results showed that the behaviour of Al with regard to organic matter was different from the behaviour of Fe.


Close

Send to a friend

The information you provide in this page are single use only and will not be saved.
* Required fields

Recipient's email:*  

Sign with your name:* 

Type your email address:*   

Add a message :

Do you want to receive a copy of this email?

Send

Cancel

Close

WP_IMPRIMER_TITLE

WP_IMPRIMER_MESSAGE

Back

Ok