Effect of contact time on the photocatalytic decolorization of
AR73 was studied in the range of 15e60 min, where the initial pH
and the photocatalyst dosage were set to 5 and 0.8 g/L, respectively.
The increase in reaction time enhanced the total COD removal
to82% (±0.23), while the AR73 was not detectable. Results indicate
the favorable effect of reaction time of 60 min on enhancing total
COD removal which means that intermediate metabolites formed
during AR73 degradation have been destructed and more efficient
mineralization was achieved. Complete removal of AR73 was
observed following the coagulation-photocatalytic degradation in
optimum determined conditions but in shorter reaction time of
25 min.
3.3.4. Kinetic anal