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El origen de los flocos de aluminio en arroyos contaminados
Gerhard Furrer1, Brian L Phillips, Kai-Uwe Ulrich
1Institute of Terrestrial Ecology, Eidgenössische Technische Hochschule Zürich, Grabenstrasse 3, CH-8952 Schlieren, Switzerland. furrer@ito.umnw.ethz.ch
Science (New York, N.Y.)
|September 28, 2002
Resumen
La minería contamina las cuencas hidrográficas con acidez, aluminio y metales pesados. Es probable que estos contaminantes se formen a partir de flocos agregados de oxihidróxido de aluminio, específicamente el nanocúmulo Al13, que se encuentra en las corrientes afectadas.
Área de la Ciencia:
- Química del medio ambiente Química del medio ambiente
- La geoquímica es la geoquímica.
- Calidad del agua Calidad del agua.
Sus antecedentes:
- Las actividades mineras perturban vastas áreas de tierra, lo que lleva a la contaminación de cuencas hidrográficas.
- Los efluentes y suelos mineros ácidos contaminan las masas de agua con acidez, aluminio y metales pesados.
- Los contaminantes se precipitan como flocos de oxihidróxido de aluminio, transportados en las corrientes como sólidos en suspensión.
Objetivo del estudio:
- Investigar la composición y el origen de los flocos de oxihidróxido de aluminio en arroyos contaminados por la minería.
- Para identificar las especies específicas de aluminio responsables de la formación de flocos y el transporte de contaminantes.
Principales métodos:
- Análisis de muestras de nueve arroyos afectados por la minería.
- Caracterización de flocos de oxihidróxido de aluminio mediante técnicas avanzadas.
- Identificación de la polioxocación de epsilon-Keggin AlO4Al12(OH)24(H2O)12(7+)(aq) (Al13) dentro de los flocos.
Principales resultados:
- Todos los flocos analizados contenían distintos centros de Al ((O) 4).
- Estos centros son estructuralmente similares a los que se encuentran en el nanocúmulo Al13.
- La evidencia sugiere que el nanocúmulo de Al13 es el precursor de los flocos de oxihidróxido de aluminio observados.
Conclusiones:
- El nanocluster Al13 es probablemente responsable de la formación de flocos de oxihidróxido de aluminio en cuencas hidrográficas contaminadas por la minería.
- Estos flocos juegan un papel importante en el transporte de contaminantes adsorbidos.
- Comprender la formación de flocos es crucial para mitigar la contaminación del agua relacionada con la minería.
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