Photocatalytic degradation of chlorophenols in soil washing wastes containing Brij 35. Correlation between the degradation kinetics and the pollutants-micelle binding.
The photocatalytic degradations of 4-chlorophenol (CP), 4-chloro-2-methylphenol (CMP), 4-chloro-3,5-dimethylphenol (CDMP) and 4-chloro-2-isopropyl-5-methylphenol (CIMP) were investigated in water and in simulated soil washing wastes containing Brij 35 (polyoxyethylene(23)dodecyl ether) in the presence of TiO2 dispersions. A neat inhibition of substrate decomposition proportional to their growing hydrophobicity was observed in the washing wastes for CP, CMP and CDMP, whereas CIMP showed a different behaviour. The mineralization of the organic chlorine of CP and CIMP was relatively fast and complete, whereas it was much slower for CMP and CDMP. Micellar solubilization and substrate adsorption onto the semiconductor play opposite roles on the degradation kinetics, and a breakpoint between the corresponding induced effects was evidenced when the pollutants become completely bound to the micellar aggregates.
Dipartimento di Chimica, Università di Torino, 10125 Turin, Italy.
M
M
Davezza
D
D
Fabbri
E
E
Pramauro
A Bianco
AB
Prevot
D000327:Adsorption; D002733:Chlorophenols / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D007700:Kinetics; D008823:Micelles; D010782:Photolysis; D011092:Polyethylene Glycols / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014877:Water Pollution, Chemical / Q000517:prevention & control*
D002733:Chlorophenols; D008823:Micelles; D012989:Soil Pollutants; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D011092:Polyethylene Glycols; D014025:Titanium; C515901:Brij 35