Rare earth elements mobility processes in an AMD-affected estuary: Huelva Estuary (SW Spain).
Mar Pollut Bull
; 121(1-2): 282-291, 2017 Aug 15.
Article
em En
| MEDLINE
| ID: mdl-28622989
ABSTRACT
Huelva Estuary is a transition zone where REE-rich acidic waters interact with saline-alkaline seawater. This mixing process influences the geochemical and mineralogical characteristics of particulate and dissolved fractions. The Tinto River has >11,000µgL-1 dissolved REE (pH=1.66), whereas seawater only reaches 8.75·10-2µgL-1 dissolved REE (pH=7.87). REE-normalized patterns in "pH<6 solutions" are parallel and show similarities, diminishing their concentration as pH increases. Sequential extraction performed on the generated precipitates of mixed solutions indicates that most REE are associated to the residual phase. In a second order, REE are associated with soluble salts at pH3 and 3.5 whereas in sediments generated at pH4 and 5, they are distributed in salts (1° extraction), poorly crystallized Fe-bearing minerals (schwertmannite, 3° extraction) and well crystallized Fe-bearing minerals (goethite - hematite, 4° extraction). Finally, precipitated REE are highest at pH6 newly formed minerals with a release to solution in higher pH.
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Base de dados:
MEDLINE
Assunto principal:
Estuários
/
Metais Terras Raras
País como assunto:
Europa
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article