Evaluación de la remoción de cromo total y níquel en humedales subsuperficiales
Fecha
2017-06
Autores
Pedrozo Alfonso, Julio César
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Editor
Universidad Central “Marta Abreu” de Las Villas. Facultad de Química Farmacia. Departamento de Licenciatura en Química
Resumen
El presente trabajo está dirigido a evaluar la remoción de níquel y cromo mediante humedales subsuperficiales. Se evalúan dos sistemas experimentales, en diferentes tiempos de exposición al metal y con tres especies de plantas. La eficiencia de remoción obtenida en el humedal plantado con Heliconia para ambos metales, es superior al 98%. Se determina además, la retención del metal en las diferentes partes de las plantas, obteniéndose una mejor capacidad de acumulación de metales en el Cyperus Alternifulius y dentro de las Heliconias la Rostrata, predominando el níquel en las hojas y el cromo en las raíces. Se efectúan extracciones simples obteniéndose las mayores concentraciones de los metales en los extractos con EDTA. Se realizan extracciones secuenciales para conocer las especies predominantes a las que se asocian los metales en el suelo, obteniéndose la mayor concentración de los metales en la fracción residual con el transcurso del tiempo. Finalmente se evalúa la cinética de remoción de los contaminantes en el humedal, alcanzándose un mejor ajuste al modelo Monod para el níquel en el humedal plantado con Heliconia, coincidiendo con lo obtenido en estudios anteriores para el Cyperus Alterniufolius.
The present work is aimed at evaluating the removal of nickel and chromium by subsurface wetlands. Two experimental systems are evaluated, in different metal exposure times and with different plant species. The removal efficiency obtained in the wetland planted with Heliconia is higher than 98% for both metals taking into account the standard solutions and the INPUD residual water. It is also determined the retention of the metal in the different parts of the plants, obtaining a better capacity of metal accumulation in the Cyperus Alternifulius and in the Rostrata, one of the Heliconia species. Besides, it is observed a predominance of nickel accumulation in the leaves due to its great bioavailability in the soil. This bioavailability coincides with the higher concentration of nickel obtained in the simple extractions with EDTA. Sequential extractions are made to know the predominant species to which the metals are associated with in the soil, obtaining the highest concentration of the metals in the residual fraction with the passage of time. Finally, the removal kinetics of pollutants in the wetland is evaluated, with a better adjustment to the Monod model for nickel in the Heliconia planted wetland, in agreement with previous studies for Cyperus Alterniufolius.
The present work is aimed at evaluating the removal of nickel and chromium by subsurface wetlands. Two experimental systems are evaluated, in different metal exposure times and with different plant species. The removal efficiency obtained in the wetland planted with Heliconia is higher than 98% for both metals taking into account the standard solutions and the INPUD residual water. It is also determined the retention of the metal in the different parts of the plants, obtaining a better capacity of metal accumulation in the Cyperus Alternifulius and in the Rostrata, one of the Heliconia species. Besides, it is observed a predominance of nickel accumulation in the leaves due to its great bioavailability in the soil. This bioavailability coincides with the higher concentration of nickel obtained in the simple extractions with EDTA. Sequential extractions are made to know the predominant species to which the metals are associated with in the soil, obtaining the highest concentration of the metals in the residual fraction with the passage of time. Finally, the removal kinetics of pollutants in the wetland is evaluated, with a better adjustment to the Monod model for nickel in the Heliconia planted wetland, in agreement with previous studies for Cyperus Alterniufolius.
Descripción
Palabras clave
Aguas Residuales, Humedales, Níquel, Cromo, Contaminación del Agua, Contaminación Ambiental, Industria Galvánica