Photodegradation kinetics of aniline, 4-ethylaniline, and 4-chloroaniline in aqueous suspension of polycrystalline titanium dioxide

The photodegradation process of aniline, 4-ethylaniline, and 4-chloroanilin e in aqueous suspension of irradiated TiO2 (anatase) powder has been invest igated. A batch photoreactor with immersed lamp irradiating in the near-UV region has been used for carrying out the reactivity experiments. For each substrate the influence of the initial concentration of organic compound an d of pH on the degradation rate has been investigated. The main intermediat es and the end products have been identified and determined, the total mass balance being satisfied. The kinetic modelling of the series of reactions occurring in the system has been satisfactorily carried out with a Langmuir -Hinshelwood rate law. The values of the parameters involved in the model h ave been also determined.