Application of H-titanate nanofibers for degradation of Congo Red in an annular slurry photoreactor

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 × 102 dm3 mol-1. The optimal photo-degradation rate of 3.47 × 10-2 mol dm-3 min-1 was achieved at 60 ppm CR, pH 3, aeration rate of 5 dm3 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 × 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 © 2008.Meng Nan Chong, Bo Jin, H.Y. Zhu, C.W.K. Chow and Chris Sain