Photocatalytic degradation kinetics of di- and tri-substituted phenolic compounds in aqueous solution by TiO2/UV

摘要: 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 TiO 2 /UV. Although degraded phenolic compound concentration increased increasing initial decomposition rates di- tri-substituted phenols at 0.1–0.5 mM concentrations decreased when the increased. The fastest observed for TCP slowest TMP. Photodegradation kinetics compounds explained in terms Langmuir–Hinshelwood model. Degradation rate constants have to be extremely depended on electronegativity substituents ring. constant adsorption equilibrium were calculated as k 0.0083 mM min −1 K 9.03 mM . For TBP TMP values obtained 0.0040 mM min , 19.20 mM 0.0017 mM min 51.68 mM respectively. DBP was similar DCP (0.0029 mM min 0.0031 mM min DCP) whereas differed (48.40 mM 30.52 mM DCP). DMP found 83.68 mM 0.0019 mM min dark ranged between 1.11 3.28 mM which are lower than those kinetics. Adsorption inversely proportion with all studied.