Use of finite element method as a simulation technique for bioremediation of naphthalene, anthracene and pyrene contaminated soil in a fixed bed reactor

Abstract

In this work, the finite element method was applied to solve one-dimensional advective-dispersive solute transport model with linear equilibrium sorption and first-order degradation. This mathematical approach was adopted to adequately predict the effluent concentrations and breakthrough profiles of naphthalene, anthracene and pyrene. Simulation results showed that the concentrations of naphthalene, anthracene and pyrene within a contact period of 49 days, decreased in the direction of flow from 100 mg/l at the surface to zero at 9 cm subsurface depth. The residual concentrations of naphthalene, anthracene and pyrene were found to be 0, 35.79 and 0% respectively by the 49th day of exposure. The theoretical predictions when compared with actual experimental results from the soil column showed an average deviation of 3.92%, an indication of a reasonable agreement between the model and data from experiment. The finite element method has been found to be satisfactory as a predictive tool to show the distribution of the contaminant solutes. This is significant as it displays the capacity of ascertaining the behaviour of these contaminants over long spatial and temporal scales and predicting the extent of bioremediation of the contaminated sites.