3 research outputs found
Evaluation of the oxygen transfer coefficient in activated sludge processes to optimize the aeration
[ES] En una Estaci贸n Depuradora de Aguas Residuales (EDAR), el mayor consumo energ茅tico es el asociado al sistema de aireaci贸n del tratamiento biol贸gico. Esto hace que los estudios relacionados con los sistemas de aireaci贸n para mejorar su eficiencia sean interesantes, ya que pueden contribuir a un descenso notable en los costes energ茅ticos de la EDAR. En este estudio se ha observado una relaci贸n positiva del coeficiente de transferencia de ox铆geno con el caudal de aire insuflado y, por el contrario, una relaci贸n negativa con el aumento en la concentraci贸n de s贸lidos totales del licor mezcla. Los resultados han demostrado que el valor del coeficiente de transferencia de ox铆geno presenta diferencias notables seg煤n la configuraci贸n de los difusores empleados y se ve afectado negativamente por el ensuciamiento de los mismos. Se han destacado tres aspectos clave para el ahorro energ茅tico en el proceso de aireaci贸n: (1) implementar un sistema de control de la aireaci贸n que ajuste la cantidad de ox铆geno suministrada a las necesidades del proceso biol贸gico, (2) disponer de soplantes dimensionadas para trabajar eficientemente en las bajas y medias necesidades (en lugar de soplantes de gran potencia dimensionadas para unas condiciones punta poco frecuentes), ya que permiten una buena regulaci贸n y (3) trabajar a bajas concentraciones de ox铆geno disuelto en el reactor, pues al aumentar la diferencia entre esta concentraci贸n y la concentraci贸n de saturaci贸n del ox铆geno, se origina un aumento en la fuerza motriz responsable de la transferencia de ox铆geno a la columna de agua. Adem谩s, en estas condiciones se favorece el desarrollo de microorganismos con mayor afinidad por el ox铆geno, lo cual mantiene la eficiencia del proceso biol贸gico. Por 煤ltimo, se ha propuesto un protocolo para la determinaci贸n del coeficiente de transferencia de ox铆geno en EDARs cuyo sistema de aireaci贸n funcione mediante per铆odos de aireaci贸n intermitentes, de forma que sea posible conocer la evoluci贸n de este par谩metro con el tiempo, lo cual es de gran utilidad para la planificaci贸n del mantenimiento y limpieza de difusores.[EN] In a Wastewater Treatment Plant (WWTP), the highest energy consumption is associated with the aeration system of the biological treatment. This makes studies related to the efficiency of the aeration systems interesting, since they can provide insights to achieve significant decrease in the energy costs of the WWTP. In this study a positive relationship of the oxygen transfer coefficient with the air flowrate supplied has been observed while a negative relationship with the increase in the total solids concentration of the mixed liquor. The results have shown that the value of the oxygen transfer coefficient shows notable differences according to the configuration of the diffusers and it is negatively affected by their fouling. Three key aspects for energy saving in the aeration process have been highlighted: (1) implement an aeration control system that adjusts the amount of oxygen supplied to the needs of the biological process, (2) have blowers sized to work efficiently in the low and medium needs (instead of high-power blowers sized for infrequent peak conditions), since they allow good regulation and (3) operate at low concentrations of dissolved oxygen in the reactor, because by increasing the difference between the concentration of dissolved oxygen in the reactor and the oxygen saturation, an increase in the driving force responsible for the transfer of oxygen to the water column will be achieved. Additionally, under these conditions, proliferation of microorganisms with a higher oxygen affinity can be promoted, which maintains the higher gradient between concentrations and improves the efficiency of the biological process. Finally, a protocol has been proposed for the determination of the oxygen transfer coefficient in WWTPs whose aeration system operated through intermittent aeration periods, so that it is possible to know the evolution of this parameter over time, which is of great value for planning maintenance and cleaning of diffusers.Se agradece a la Entidad P煤blica de Saneamiento de Aguas Residuales de la Comunidad Valenciana (EPSAR), a la C谩tedra Aguas de Valencia y a la empresa Global Ommium, tanto la financiaci贸n como la colaboraci贸n en la realizaci贸n de este trabajo.Ivailova Petkova, I.; Sol铆s, JJ.; Bes Pi谩, MA.; Aguado Garc铆a, D. (2020). Evaluaci贸n del coeficiente de transferencia de ox铆geno en procesos de fangos activados para optimizar la aireaci贸n. 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