Role of Organic Matter in the Adsorption/Desorption of Cr, Cu and Pb in Competitive Systems in Two Different Soils

Leandro Antunes Mendes¹, Luis Felipe Perez Bucater², Maria Diva Landgraf¹, Maria Olímpia Oliveira Rezende¹

¹Institute of Chemistry of São Carlos, University of São Paulo, São Paulo, Brazil.
²Engineering School of São Carlos, University of São Paulo, São Paulo, Brazil.

DOI: 10.4236/oalib.1101022                

Abstract

The various methods of remediation of contaminated soils include isolation, immobilization, toxicity reduction, physical separation and extraction. In this context, a noteworthy technique is vermicomposting, which uses worms to break down recent organic matter, turning it into a chemically more stable form able to retain metal ions, rendering them unavailable to the environment. To understand the transport of these elements in the soil, it is necessary to study their dynamics in the environment. Thus, the aim of this study was to evaluate the adsorption and desorption of metal species in soils, assessing the influence of added organic matter in order to assess the risk that these elements carry to the environment and human health. The curves of adsorption of three toxic elements in the soil were determined by adding a solution of metal salts at various concentrations, leaving 24 h centrifuging and analyzing the supernatant. The concentrations of adsorbed components were taken as the difference between those added initially and those remaining after the equilibration (C_e). Desorption was carried out by adding a solution of 0.01 mol·L^-1 CaCl₂·2H₂O to soil samples where the metal ions were adsorbed. Following the same procedure, the concentrations of desorbed metal ions were measured.

Keywords

Vermicomposting, Sorption of Metal Species in Soils, Remediation, Contaminated Soils

Conflicts of Interest

The authors declare no conflicts of interest.

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