A series of experiments were conducted to investigate the kinetics of atrazine (AT) degradation, photocatalytic degradation mechanism and degradation pathways using H3PW12O40/Ag-TiO2 as photocatalyst. The effects of experimental parameters including catalyst amount, initial concentration of the substrate, and solution pH value on AT degradation rates were evaluated. The results showed that the removal of AT followed a pseudo-first-order reaction kinetic. The highest photocatalytic degradation efficiency was obtained using H3PW12O40/Ag-TiO2 (19.7,0.8) with catalyst amount of 1.0 g L-1 and AT initial concentration of 5 mg L-1 at pH value of 3.4. The investigation of photocatalytic mechanism indicated that hydroxyl radical (center dot OH) was the major reactive species for the photocatalytic reactions of AT compared with photohole (h(+)). Ten photoproducts were observed during the AT photodegradation process. Based on the identified intermediates, two tentative degradation pathways for the photocatalytic degradation of AT were proposed. (C) 2013 Elsevier B.V. All rights reserved.