Photocatalytic degradation of 2-chlorophenol: a study of kinetics, intermediates and biodegradability.
The kinetics of photocatalytic (TiO(2)/UV) degradation of 2-chlorophenol (2-CP), characterization of intermediates and induction of biodegradability in treated chlorophenol solutions is reported. Approximately 95% of the 2-CP is removed in approximately 2h at pH 5 and 0.2g TiO(2)l(-1) when the 2-CP concentration is < or =100mgl(-1); the pseudo-first-order rate constant (k) is estimated to be 0.0183 min(-1). GC-MS analyses detected phenol, catechol, hydroxyhydroquinone (HHQ), and chlorohydroquinone (CHQ) intermediates during the short irradiation time (<1h); however two other higher carbon intermediates 2-hydroxy-benzaldehyde (HB) and [1.1'-biphenyl]-2,2'-diol (BPD) are found as major intermediates over longer irradiation times. The biochemical oxygen demand (BOD) of treated 2-CP solutions improved substantially. A tentative mechanistic pathway to explain formation of higher carbon intermediates is presented.
Rao
N N
NN
Wastewater Technology Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur, 440020, India. wwtdiv@nagpur.dot.net.in
Dubey
A K
AK
Mohanty
S
S
Khare
P
P
Jain
R
R
Kaul
S N
SN
D001673:Biodegradation, Environmental; D002384:Catalysis; D002733:Chlorophenols / Q000737:chemistry* / Q000378:metabolism*; D004396:Coloring Agents / Q000737:chemistry; D004785:Environmental Pollutants / Q000378:metabolism*; D004787:Environmental Pollution / Q000517:prevention & control; D007700:Kinetics; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry; D014466:Ultraviolet Rays
D002733:Chlorophenols; D004396:Coloring Agents; D004785:Environmental Pollutants; C009495:titanium dioxide; D014025:Titanium; C030683:2-chlorophenol