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Los controles de nitrato en el hierro y el arsénico en un lago urbano
David B Senn1, Harold F Hemond
1Parsons Laboratory, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. dbsenn@alum.mit.edu
Science (New York, N.Y.)
|June 29, 2002
Resumen
La contaminación por nitratos en los ecosistemas acuáticos impulsa el ciclo del arsénico en condiciones anóxicas. Este proceso implica la oxidación del hierro y promueve el dominio de las especies de arsénico reactivo a partículas, lo que afecta la calidad del agua.
Área de la Ciencia:
- Ciencias ambientales Ciencias ambientales.
- La geoquímica es la geoquímica.
- Química acuática Química acuática es la química acuática.
Sus antecedentes:
- Los ecosistemas acuáticos con frecuencia se enfrentan a la contaminación de múltiples contaminantes.
- El nitrato es un contaminante acuático prevalente con implicaciones ambientales significativas.
Objetivo del estudio:
- Investigar la influencia del nitrato en el ciclo del arsénico en entornos acuáticos anóxicos.
- Aclarar los mecanismos por los cuales el nitrato afecta la especiación y la reactividad del arsénico.
Principales métodos:
- Estudio de campo en un lago urbano (Lago Místico Superior, Massachusetts, EE.UU.).
- Análisis de la química del agua en condiciones anóxicas.
- Evaluación de la especiación del arsénico y la interacción con los óxidos de hierro.
Principales resultados:
- El nitrato alteró significativamente el ciclo del arsénico en condiciones anóxicas.
- Oxidación del hierro ferroso [Fe (II) ] por nitrato producido por óxidos férricos hidráulicos adsorbentes de arsénico.
- Las especies de arsénico (V) más reactivas a las partículas se volvieron dominantes sobre el arsénico (III).
Conclusiones:
- El nitrato juega un papel crucial en el control del destino y el transporte del arsénico en aguas anóxicas.
- Es probable que los mecanismos observados sean relevantes para muchos sistemas acuáticos naturales.
- Comprender estas interacciones es vital para manejar la contaminación por arsénico.
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