Kinetic study of 2-nitrophenol photodegradation on Al-pillared montmorillonite doped with copper.

Abstract

This work concerns the kinetic study of heterogeneous photocatalytic processes on copper adsorbed on aluminium-pillared montmorillonite. Photomineralization of 2-nitrophenol in aqueous medium was investigated as a function of the following experimental parameters: initial concentration of pollutant, light intensity, initial concentration of hydroperoxide, catalyst concentration, pH and temperature. The kinetic expression obtained can be described by the formula: V(NP) = k(0)exp(-Ea/RT)I(beta) x (K(NP)[NP]K(H2O2)[H2O2]/ [1+K(NP)[NP]0)(1+K(H2O2)[H2O2])] The apparent overall activation energy obtained for 2-nitrophenol was 28 kJ mol(-1). By fitting the above equation with the experimental data and values for beta (1.94), K(H2O2) (32.291 mol(-1)) and K(NP) (47.25 x 10(2)l mol(-1)), the kinetic equation can predict the concentration of 2-nitrophenol during the entire degradation process at pH 5 and a catalyst concentration of 0.5 g l(-1).