Applying Freundlich, Langmuir and Temkin models in Cu and Pb soil sorption experiments Uso de los modelos de Freundlich, Langmuir y Temkin en experimentos de sorción de Cu y Pb en suelos Aplica o dos modelos de Freundlich, Langmuir e Temkin em ensaios de sor o de Cu e Pb no solo

In acid soils, inputs of Cu and Pb of various origins create a high risk of environmental pollution. For this reason, batch experiments on Cu and Pb sorption and desorption in various horizons of three acid soils were performed on soil pH with 0.01 M NaNO3 as background electrolyte. The objectives were to evaluate Cu and Pb sorption and retention capacity through the Langmuir, Freundlich and Temkin equations parameters fitted to the sorption/desorption data; to determine the coherence of the implications of these parameters; and to estimate the role of various soil characteristics in the Cu and Pb immobilization soil capacity. The results confirmed the suitability of the models parameters for studying Cu and Pb sorption and retention by acid soils. The greatest maximum sorption and retention capacities, indicated by the Langmuir parameter L, corresponded to the lowest energy values required for fixation, indicated by the Temkin parameter b . Together with the Freundlich parameter KF, which indicates sorption and retention capacity, they made it possible to infer that the acid soil component that most influences Cu and Pb immobilization was the organic matter, followed by the Al-oxide content. High organic matter and Al-oxide contents, especially the former, gave rise to a lower energy requirement for the immobilization of metal cations, since they increased the soils sorption and retention capacities. Al3+, the dominant cation in the exchange complex in the horizons studied, and K+ are responsible for the influence of CECe on Cu and Pb immobilization in the acid soils studied. El aporte de Cu y Pb a través de diversas fuentes a suelos ácidos supone un alto riesgo de contaminación medioambiental. Por ello, usando el método batch y con NaNO3 0,01 M como electrolito de fondo, se llevaron a cabo, al pH del suelo, experimentos de sorción y desorción de ambos elementos en muestras de todos los horizontes de tres suelos ácidos. Los objetivos fueron evaluar la capacidad de sorción y retención de Cu y Pb a través de los parámetros derivados de los ajustes a los modelos de Langmuir, Freundlich y Temkin; determinar la coherencia de las conclusiones deducidas de dichos parámetros, y estimar el papel de las características de todos los horizontes de esos suelos ácidos en la capacidad de fijación de Cu y Pb. Los resultados confirmaron la idoneidad del uso de los parámetros de las ecuaciones de Langmuir, Freundlich y Temkin para estudiar la sorción y retención de Cu y Pb por los suelos ácidos, ya que permitieron deducir que los mayores valores de la máxima capacidad