Equilibrios de distribución de metales pesados entre la fase acuosa y la superficie de lodos residuales, generados por plantas de tratamiento aerobio para aguas negras

Abstract

Several sorption isotherms were performed in order to establish the distribution of three metals: Cadmium, Zinc and Nickel, between the aqueous phase and the solid surface of a residual sludge from a wastewater treatment plant, the principal aim of this research was to determine the sorption capacity and the minimal conditions needed to integrate the residual sludge in treatment systems for those effluents contaminated with high concentrations of heavy metals. The obtained data were adjusted with the Langmuir and Freundlich linear expressions, finding a better adjustment with the first one. The resulting affinity of the metals for the organic binder (biosorbent) follows the sequence: Cd > Zn > Ni. It was observed that the sorption capacity is directly related to the pH conditions, the biomass concentration and its activity and also to an initial metal concentration in the sludge due to an original source contamination.