Adsorption of zinc and its relationship with characteristics of soils of Paraíba State, Brazil

Abstract

The present study examined the adsorption of zinc and its relationship with characteristics of eleven soils from the State of Paraíba, Brazil, with a wide range of chemical properties. In order to quantify the adsorbed Zn, 2 g of air-dried soil were stired in tubes, for 2 h with 20 mL of a NaCl (0,01 M) solution containing different quantities of Zn (1, 2, 5, 10, 15, 30, 40, 50, 60, 70, 80, 90 mg L^-1). The Langmuir equation was adequate for providing Zn adsorption coefficients. The cation exchange capacity was the soil property that best correlated to Zn adsorption of soils. The pH, organic carbon, remaining P and the clay contents were not correlated to coefficients of Zn adsorption. Soils with clay of high activity and wethered soils presented highest and lowest maximum adsorption capacity, respectively.