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Difusión intragranular: ¿un mecanismo importante que influye en el transporte de solutos en los acuíferos clásicos?
Science (New York, N.Y.)
|March 30, 1990
Resumen
La porosidad intragranular en la arena del acuífero es mayor de lo medido anteriormente, revelando más sitios de reacción. Este hallazgo requiere incluir expresiones de difusión en modelos de transporte para la simulación de residuos radiactivos y tóxicos.
Área de la Ciencia:
- Geología Geología Geología.
- Ciencias del medio ambiente Ciencias del medio ambiente.
- La hidrogeología es la hidrogeología.
Sus antecedentes:
- Las pruebas de laboratorio estándar subestiman la porosidad intragranular en la arena del acuífero.
- Las propiedades de los acuíferos influyen significativamente en el transporte de solutos y el destino de los contaminantes.
Objetivo del estudio:
- Para cuantificar con precisión la porosidad intragranular en un material acuífero del tamaño de la arena.
- Para evaluar el impacto de esta porosidad en el transporte de soluto y la cinética de reacción.
Principales métodos:
- Microscopía electrónica de barrido (SEM)
- Porosimetría por inyección de mercurio.
- Microscopía por epifluorescencia con microscopía por epifluorescencia.
- Pruebas de trazador de laboratorio y de campo.
Principales resultados:
- La porosidad intragranular y los sitios de reacción son significativamente mayores de lo indicado por los métodos estándar.
- Las pruebas de trazador revelaron un desequilibrio de soluto, consistente con la difusión y el intercambio dentro de los interiores de los granos.
- Los fenómenos observados requieren una comprensión revisada del transporte de soluto en medios porosos.
Conclusiones:
- Las técnicas de medición estándar no logran capturar toda la extensión de la porosidad y los sitios de reacción en las arenas de los acuíferos.
- La difusión en el interior de los granos es un proceso crítico que influye en el transporte de solutos, especialmente para los contaminantes reactivos.
- Los modelos de transporte requieren expresiones de difusión actualizadas para una simulación precisa de la migración de contaminantes, particularmente para desechos radiactivos y tóxicos.
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