Anatase nanofibers (TiO2-N) were synthesized as photocatalyst for the application in an annular slurry photoreactor (ASP). The unique properties of TiO2-N have facilitated its high reactivity and suitability for water treatment. The influence of operational variables: TiO2-N loading, pH, aeration rate and dye concentration on the photo-degradation kinetics and efficiency to remove a model compound of Congo Red (CR) were investigated. The photo-degradation kinetics of CR followed the Langmuir-Hinshelwood regime at lower pH. The Langmuir adsorption constant. KL-H was determined as 7.695 x 10(2) dm(3) mol(-1). The optimal photo-degradation rate of 3.47 x 10(-2) mol dm(-3) min(-1) was achieved at 60 ppm CR, pH 3, aeration rate of 5 dm(3) min(-1) and TiO2-N loading of 4 g dm(-3). Batch settling tests based on Kynch's theory revealed that the TiO2-N photocatalysts could produce a settling velocity of 8.38 x 10(-4) ms(-1). It Was expected that these novel TiO2-N particles can deliver a true engineering Solution as an industrial process for photocatalytic water treatment. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.