Resumen

CORTES PAEZ, Luis Enrique; BRAVO REALPE, Isabel del Socorro; MARTIN PEINADO, Francisco José  y  MENJIVAR FLORES, Juan Carlos. Adsorption of heavy metals in andisols, vertisols and humic acids. Acta Agron. [online]. 2015, vol.64, n.1, pp.61-71. ISSN 0120-2812.  https://doi.org/10.15446/acag.v64n1.43677.

This research studied the adsorption of five heavy metals (Cd, Cu, Ni, Pb and Zn) in three adsorbents, two Colombian agricultural soils (Typic Melanudand and fine clay 1% isohyperthermic-Ustic Epiaquert) and humic acids (HA) extracted from leonardite, of Spain. In both, HA and soils, the chemical properties determined were: pH, cation exchange capacity (CEC), organic carbon (% OC), exchangeable bases and total content of metals. The chemical composition of HA was determined using spectrometric techniques as ICP_MS, FTIR, UV-Vis, and CPMAS ¹³C NMR and Py-GC/MS-THMA. The results from the adsorption of metals in the three adsorbents were adjusted to Freundlich model, and these show a different behavior of the absorbers relative to the metals studied, in the same way the maximum adsorption capacity (K) and the retention force (n) of metals is significantly different (p <0.05). According to K and n of each adsorbent, the adsorption selectivity sequences of the metals has the following order of preference for K: In Humic Acids: Cd> Pb> Cu> Ni> Zn, Andisol: Pb> Cu> Cd> Zn> Ni, and Vertisol: Cd> Pb> Cu> Ni> Zn. For n, Humic Acids: Pb> Zn> Cd> Cu> Ni, Andisol: Cu> Ni> Zn> Pb> Cd, and Vertisol: Zn> Ni> Cu> Pb> Cd

Palabras clave : Soils; humic acids; adsorption; sorption isotherms; heavy metals.

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