Kinetic Modelling of Nitrate Removal from Aqueous Solution during Electrocoagulation

Abstract

The present study focuses on the prediction of mathematical model that describes the nitrate removal from an aqueous solution by means of electrochemical techniques. The nitrate removal was modeled by applying the kinetic reaction rate equations and the adsorption isotherms. The experimental part of this study was implied to investigate the performance of nitrate removal from an aqueous solution by utilizing an electrochemical method (i.e. electrocoagulation). Experiments were carried out to treat a synthetic strength aqueous solution of 150 mg/l NO3? concentration through batchwise mode. The nitrates removal from aqueous solution was studied as a function of the electrocoagulation time, and the applied current density with iron MP-P connected electrodes. The theoretical part of this study was attempted to conform the nitrate removal data to Langergren pseudo first order, Ho pseudo second order and Elovich kinetic models. The equilibrium results were analyzed by the adsorption isotherms Langmuir, Freundlich and Temkin. Based on correlation coefficient, it has been found that the NO3? electrocoagulation with ferric(III) hydroxides adsorbent can be extremely represented by the pseudo second order reaction kinetic model, and the equilibrium data found better fit to Freundlich equilibrium isotherm. Key words: NO3? removal, Electrocoagulation, kinetic models, adsorption isotherms.