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Retardo del transporte de arsénico a través de un acuífero del Pleistoceno
Alexander van Geen1, Benjamín C Bostick, Thi Kim Trang Pham
1Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA. avangeen@ldeo.columbia.edu
Nature
|September 13, 2013
Resumen
El bombeo de agua subterránea en el sudeste asiático está contaminando acuíferos seguros del Pleistoceno con arsénico de fuentes poco profundas del Holoceno. El arsénico es arsénico.
Área de la Ciencia:
- Ciencias ambientales Ciencias ambientales.
- La hidrogeología es la hidrogeología.
- La geoquímica es la geoquímica.
Sus antecedentes:
- Millones de personas en el sur y sudeste de Asia se enfrentan a la intoxicación por arsénico de los acuíferos poco profundos del Holoceno.
- Los acuíferos del Pleistoceno, más antiguos y típicamente libres de arsénico, son una alternativa más segura para el agua potable.
- Comprender la dinámica de la contaminación en los acuíferos del Pleistoceno es crucial para la salud pública.
Objetivo del estudio:
- Para reconstruir la fase inicial de contaminación por arsénico en un acuífero del Pleistoceno cerca de Hanoi, Vietnam.
- Para investigar cómo el bombeo de agua subterránea impacta los niveles de arsénico en los acuíferos del Pleistoceno.
- Evaluar los factores que controlan el transporte y retraso del arsénico en los sistemas acuíferos.
Principales métodos:
- Reconstrucción de las fases iniciales de contaminación.
- Análisis de las condiciones de flujo de las aguas subterráneas y cambios en el estado redox.
- Medición de la adsorción y retardo de transporte de arsénico en las arenas de los acuíferos.
Principales resultados:
- El bombeo de agua subterránea indujo la intrusión lateral de la contaminación por arsénico (>120m) del Holoceno en los acuíferos del Pleistoceno.
- La adsorción de arsénico en las arenas de los acuíferos causó un retraso significativo en el transporte (16-20 veces).
- La contaminación de los acuíferos del Pleistoceno por arsénico puede retrasarse por el retraso en el transporte.
Conclusiones:
- El bombeo de agua subterránea puede movilizar el arsénico de fuentes poco profundas a acuíferos más profundos, previamente seguros.
- El transporte de arsénico se retrasa significativamente por adsorción, lo que podría retrasar la contaminación generalizada.
- Las estrategias de gestión de los recursos hídricos subterráneos deben tener en cuenta la movilización de arsénico y la dinámica de transporte.
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