Health & Environmental Research Online (HERO)


Print Feedback Export to File
4286296 
Journal Article 
Heterogeneous photocatalytic oxidation of nitrotoluenes 
Kumar, S; Davis, AP 
1997 
1 
Water Environment Research
ISSN: 1061-4303
EISSN: 1554-7531 
WATER ENVIRONMENT FEDERATION 
ALEXANDRIA 
BIOSIS/98/03458 
69 
7 
1238-1245 
English 
WOS:A1997YK56500007 
BIOSIS COPYRIGHT: BIOL ABS. The photocatalytic oxidation rates of nitrotoluene (2-NT and 3-NT) and dinitrotoluene (2,4-DNT and 2,6-DNT) in aqueous suspensions of Degussa P-25 were found to be pH independent because these compounds do not exhibit any pH-dependent speciation. The reaction rates of mononitrotoluenes were found to be 60 to 80% greater than those of dinitrotoluenes. A Langmuir-Hinshelwood (L-H) rate form is used to describe the kinetics of the photocatalytic oxidation of these compounds. The L-H constant k1 has been found to be essentially independent of the compound being degraded. At low concentrations, the reaction rates of nitrotoluenes decrease with increasing nitration. This has been explained through the electron-withdrawing characteristics of the nitro group, employing the Hammett relationship, with the reaction rates following the sequence: Toluene and gt; 3-NT and gt; 2-NT and gt; 2,4-DNT and gt; 2,6-DNT and gt; TNT (trinitrotoluene, predicted). The photocatalytic oxidation of 2,6-DNT produ 
Nitrotoluenes; Photocatalytic oxidation; Reaction rates; Titanium dioxide; Ultraviolet irradiation