Zn (II) AND Pb (II) ADSORPTION ON TO AGRICULTURAL SOILS FROM EAST OF ALGERIA

Soil properties have an important role in the movement of minerals in the environment. Therefore, the study of mineral adsorption and soil properties can help solve environmental pollution problems. In the present work, batch adsorption of zinc and lead was studied on some Algerian soils (clay soil, sandy loam soil, and sandy soil), as a function of contact time, pH, metal concentration and physicochemical properties. The results showed the metal adsorption amount depends on soil pH and initial ion concentration, soil type, temperature, exchange capacity, and metal hydrolysis. Ionic strength and organic matter content investigation indicate that, clay soil presents greater adsorption of both metals than the two other soils. The metal ions’ adsorption decreases with decreasing pH and increasing ionic strength. The results showed that the adsorption amount of lead is better than that of zinc in all studied samples. The equilibrium data good fit well with Langmuir and Freundlich’s models. The tested kinetic models showed that soil adsorption of these metals are biphasic and diffusion-controlled process. For all pH values, the adsorption was relatively fast at the beginning followed by a slower phase at reaching the equilibrium time.