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Sulfatos primarios en los sulfatos atmosféricos: estimación mediante mediciones de la relación de isótopos de oxígeno
Science (New York, N.Y.)
|July 2, 1982
Resumen
Las relaciones estables de isótopos de oxígeno revelan que el 20-30% de los sulfatos en la precipitación en Argonne, Illinois, se originan a partir de emisiones primarias, no de la formación secundaria de dióxido de azufre.
Área de la Ciencia:
- Química del medio ambiente Química del medio ambiente
- Ciencias de la atmósfera Ciencias atmosféricas.
- La geoquímica de los isótopos es la geoquímica de los isótopos.
Sus antecedentes:
- Los sulfatos atmosféricos se originan tanto en las emisiones primarias como en la formación secundaria.
- Diferenciar estas fuentes es crucial para comprender la química atmosférica y la contaminación.
- Los isótopos estables de oxígeno ofrecen un método potencial para la distribución de fuentes.
Objetivo del estudio:
- Utilizar relaciones estables de isótopos de oxígeno para cuantificar las contribuciones de sulfatos primarios y secundarios en aerosoles atmosféricos y precipitación.
- Para determinar la proporción de sulfatos primarios en la precipitación en un lugar específico.
Principales métodos:
- Medición de las relaciones de isótopos estables de oxígeno (oxígeno-18) en muestras de sulfato.
- Comparación del contenido de oxígeno-18 en sulfatos de diferentes vías de formación (pre-emisión vs. post-emisión).
Principales resultados:
- Los sulfatos formados en los gases de pila de las centrales eléctricas (primario) exhiben un contenido de oxígeno-18 significativamente mayor que los formados por el dióxido de azufre atmosférico (secundario).
- El análisis de muestras de lluvia y nieve de Argonne, Illinois, indicó que del 20 al 30 por ciento del contenido total de sulfatos era de origen primario.
Conclusiones:
- El análisis de isótopos estables de oxígeno es un método eficaz para distinguir y cuantificar las fuentes primarias y secundarias de sulfato en la precipitación.
- Una fracción significativa de la deposición de sulfato en la región estudiada se origina directamente de las emisiones industriales.
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