Sorption–Desorption of Cu by a Rhodic Kandiustult in the Northern Guinea Savanna of Nigeria

Abstract

Copper adsorption at concentrations between 0 to 50 mg Cu l^-1 was evaluated in surface and subsurface samples of a basaltic soil in the Northern guinea savanna, a Rhodic kandiustult. After adsorption, 3 consecutive extractions (desorption)
in sequence were performed to the samples by using 25 ml of 0.IN HCl. The results showed that the Ap and Bt horizons have large capacities to adsorb copper. While the desorption showed that the sorbed Cu was not rigidly bound. The amount of Cu released in the Ap horizon was slightly more than that released in the Bt horizon, i.e. Cu was more difficult to release in the Bt horizon than in the Ap horizon. The adsorption data did not fit the linear form of either the Langmuir or Freundlich equations.

Keywords: Adsorption, desorption, Rhodic Kandiustult, sequential extractions

Nigerian Journal of Soil and Environmental Research Vol. 7 2007: pp. 23-32