ENERGIA LIVRE DA REAÇÃO DE ADSORÇÃO DO CÁDMIO EM LUVISSOLOS E CAMBISSOLOS

Abstract

The mobility and persistency of cadmium in the soil are determined by the intensity of adsorption by colloids. The evaluation of the free energy of cadmium adsorption by the soil is a measurement of the reaction strength. This study was carried out to evaluate the free energy of cadmium adsorption reaction in Luvisol and Cambisol samples after addition of different cadmium level. Cadmium adsorption was considered spontaneous, since free energy was negative. Free energy values decreased with increasing cadmium concentration and they were higher in samples with higher organic matter levels. Luvisol showed higher values of free energy of adsorption.