Abstract:
Photocatalytic degradation of 100 mg/l chlorophenols was studied using TiO2 and Fenton
reagent as catalysts. 2-chlorophenol, 4-chlorophenol, and 2,4-dichlorophenol were selected as the target
compounds. Results showed that direct photolysis of chlorophenols was faster than that in the
TiO2-amended system. The photodegradation of 2CP followed a first-order rate relationship and the rate
constants were 0.022 and 0.0103 min–1 in direct photolysis and TiO2/UV systems, respectively. The
apparent-first-order reaction rate for decomposition of 4-chlorophenol was higher than that for
2-chlorophenol and 2,4-dichlorophenol under acidic conditions, while 2,4-dichlorophenol was higher than
2-chlorophenol and 4-chlorophenol in an alkaline medium. Both the TiO2 catalyst system and direct
photolysis process were faster in basic medium than acidic and neutral medium processes. The Fenton
system is excellent for the degradation of chlorophenols and its activity has become low in high pH medium.
