Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9609888 | Applied Catalysis B: Environmental | 2005 | 6 Pages |
Abstract
In this study, photocatalytic degradation of 2,4,6-trimethylphenol (TMP), 2,4,6-trichlorophenol (TCP), 2,4,6-tribromophenol (TBP), 2,4-dimethylphenol (DMP), 2,4-dichlorophenol (DCP) and 2,4-dibromophenol (DBP) has been studied by TiO2/UV. Although degraded phenolic compound concentration increased by increasing initial concentration photocatalytic decomposition rates of di- and tri-substituted phenols at 0.1-0.5Â mM initial concentrations decreased when the initial concentration increased. The fastest degradation observed for TCP and the slowest for TMP. Photodegradation kinetics of the compounds has been explained in terms of Langmuir-Hinshelwood kinetics model. Degradation rate constants have been observed to be extremely depended on electronegativity of the substituents on phenolic ring. Degradation rate constant and adsorption equilibrium constant of TCP were calculated as k 0.0083Â mMÂ minâ1 and K 9.03Â mMâ1. For TBP and TMP the values of k and K were obtained as 0.0040Â mMÂ minâ1, 19.20Â mMâ1, and 0.0017Â mMÂ minâ1, 51.68Â mMâ1, respectively. Degradation rate constant of DBP was similar as DCP (0.0029Â mMÂ minâ1 for DBP and 0.0031Â mMÂ minâ1 for DCP) whereas adsorption equilibrium constants differed (48.40Â mMâ1 for DBP and 30.52Â mMâ1 for DCP). K and k of DMP found as 83.68Â mMâ1 and 0.0019Â mMÂ minâ1, respectively. The adsorption equilibrium constants in the dark were ranged between 1.11 and 3.28Â mMâ1 which are lower than those obtained in kinetics. Adsorption constants have inversely proportion with degradation rate constants for all phenolic compounds studied.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Catalysis
Authors
Erdal Kusvuran, Ali Samil, Osman Malik Atanur, Oktay Erbatur,