Kinetic studies for nitrate adsorption on granular chitosan–Fe(III) complex

In this study, a generalized kinetic equation was proposed to simulate adsorption behaviors in batch systems and several useful kinetic equations were deduced. The results indicated that the amount of nitrate uptake increased rapidly in the initial stage, followed by a slower process until adsorption equilibrium was reached after approximately 1.5 h. The rate constant was a function of the initial nitrate concentration. The adsorption and desorption rate constants quantitatively reflected the adsorption and desorption reactions at the solid/solution interface. The adsorption and desorption processes for nitrate adsorption followed identical reaction order. The kinetic parameters (adsorption and desorption rate constants, half-time and instantaneous rate) provided by these kinetic equations are of significant importance for the understanding of adsorption mechanisms.