The photocatalytic decolorization of C.I. Basic Blue 3 (BB3) solution on immobilized TiO2 nanoparticles was carried out in a rectangular flat-plate photoreactor. The investigated TiO2 was Millennium PC-500 (anatase, average crystallite size 8 nm, surface area 320.76 m(2) g(-1)) immobilized on non-woven paper. A new kinetic model was proposed on the basis of intrinsic element reactions. The proposed kinetic model fairly resembled the classic Langmuir-Hinshelwood (L-H) equation from its expression. It was found that both k(obs) (the reaction rate constant) and K-R (the adsorption rate constant) were linearly proportional to the light intensity in a rather large intensity range. (C) 2011 The Institution of chemical Engineers. Published by Elsevier B.V. All rights reserved.