Modeling of Phytoremediation Period of Nickel in Polluteded soil

In recent decades, heavy metal treatment due to environmental hazards is highly been considered. Among the various methods remediation, phytoremediation or in other words metal accumulation in plants is a new, reliable and economical method. But the efficiency of this method should be evaluated by mathematical models. The objective of this study, therefore, is to present a simple model for evaluating the period of remediation soil Nickel by the basil (Ocimum tenuiflorum L) plant. For this purpose, the soil adsorption isotherm were assumed to represent the soil behavior against the contaminant and were therefore combined with the plant uptake rates in order to develop simple models to predict the period needed for remediation of soil. The soil was contaminated with different levels of Nickel to permit the model evaluation. To verify model, The soil was contaminated with different amounts of nickel. Nickel Nitrate was used to contaminate the soil. The contaminated soils were then packed into the pots and. Basil basil (Ocimum tenuiflorum L) seeds were planted in the pots.. Crop samples were taken at four different time stages. In each step, The total concentrations of Ni in the soil and plant samples and water- soluble fraction of soil Ni were extracted. The models applicability was verified by mathematical statistic approaches. The results indicated the high performance of the Freundlich (R2=0.93) and the linear (R2=0.91) isotherm models to predict the Ni adsorption on soil. The result also showed that phytoremediation rate of Ni by Basil is a zero-order function of Ni concentration in soil solution. The comparison of the calculated and measured period of remediation soil Nickel by basil proofed the great performance of the proposed models.