title: Photocatalytic oxidation of toxic organohalides with TiO2/UV: the effects of humic substances and organic mixtures.
abstract: TiO2/UV photocatalytic oxidation of DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane), 1,2,3-trichlorobenzene and 4-chlorophenol were examined in aqueous solution in the presence of humic substances and organic mixtures to study if the degradation rates were affected. Both commercial and natural humic substances were observed to retard the photodegradation rates, with a greater effect from the natural humic substances. Acetonitrile and isopropanol also caused significant retardation of 4-chlorophenol photodegradation. The overall retardation can be attributed to the combination of light attenuation, inhibition and competition effects. Moreover, the TiO2/UV system favors the decomposition of compounds that have stronger adsorption onto the TiO2 surface. To engineer effective treatment facilities that use the TiO2/UV system for the treatment of toxic substances in wastewater, the methodology must allow for concerns about adventitious species which are present.
authors.affiliation: Department of Marine Environmental Engineering, National Kaohsiung Marine University, 142 Hai-Chuan Road, Nan-Tzu District, Kaohsiung 811, Taiwan, ROC.
authors.forename: Chitsan
authors.initials: C
authors.lastname: Lin
authors.forename: Kuen-Song
authors.initials: KS
authors.lastname: Lin
mesh_terms: D019840:2-Propanol / Q000737:chemistry; D000097:Acetonitriles / Q000737:chemistry; D002384:Catalysis; D002722:Chlorobenzenes / Q000737:chemistry; D002733:Chlorophenols / Q000737:chemistry; D003634:DDT / Q000737:chemistry; D006812:Humic Substances; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry*; D010084:Oxidation-Reduction / Q000528:radiation effects; D010777:Photochemistry / Q000379:methods; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D000097:Acetonitriles; D002722:Chlorobenzenes; D002733:Chlorophenols; D006812:Humic Substances; D006843:Hydrocarbons, Chlorinated; D009930:Organic Chemicals; C036720:trichlorobenzene; C009495:titanium dioxide; C029107:4-chlorophenol; D003634:DDT; D014025:Titanium; D019840:2-Propanol; C032159:acetonitrile