Adsorption of Nickel on Soil as a Function of Time and Metal Concentration

Nickel (Ni), one of the toxic heavy metals is widely distributed in soil and water ecosystem. Its impact on environment mainly depends on the chemistry of soil. Topredict theproblems associated with the toxicity of Ni, a better understanding of adsorption of Ni is required. Adsorption is the foremost process which occurs when metals come in contact with the soil. In this study a series of laboratory batch experiments were conducted to study the adsorption behavior of Ni in soil. For adsorption of Ni, the equilibrium period was found that 12 hours and the maximum adsorption (90.45 mg kg⁻¹) was obtained with the highest concentration of Ni added (100 mg kg⁻¹). Langmuir isotherm (R²=0.72) was best fit for adsorption of Ni when compared with Freundlich isotherm (R²=0.39). From the results it is inferred that the adsorption behavior of Ni is well explainedby Langmuir isotherm. A study about the adsorption of Ni on soil is important for prediction of toxicity effects of Ni in soil.