title: Photocatalytic degradation of polycyclic aromatic hydrocarbon benzo[a]pyrene by iron oxides and identification of degradation products.
abstract: Photocatalytic decay profiles of polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (B[a]P) have been investigated on various synthesized iron oxides and on soil surfaces under a set of diverse conditions. Samples were analysed using the developed HPLC procedure. Results of the present study demonstrate fastest photodisintegration of B[a]P on goethite followed by haematite, magnetite, akaganeite and maghemite, respectively. The effect of soil pH, irradiation wavelength and iron oxide and oxalic acid dose on the degradation of B[a]P was evaluated. The studies revealed enhancement in photodegradation in the presence of oxalic acid due to the occurrence of fenton like reaction. The results showed faster B[a]P degradation under short wavelength UV radiation. Rate constants in acidic, neutral and alkaline soils under optimum dissipation conditions were 1.11×10(-2), 7.69×10(-3) and 9.97×10(-3) h(-1), respectively. The study indicates that iron oxides along with oxalic acid are effective photocatalyst for the remediation of benzo[a]pyrene contaminated soil surfaces. The degradation products of B[a]P in the soils of different pH in presence of goethite were identified and degradation pathways proposed. Peaks due to toxic metabolites such as diones, diols and epoxides disappear after 120 h in all the three soils.
authors.affiliation: Department of Chemistry Indian Institute of Technology Roorkee, Roorkee 247667, U.K., India.
authors.forename: Himanshu
authors.initials: H
authors.lastname: Gupta
authors.affiliation: Department of Chemistry Indian Institute of Technology Roorkee, Roorkee 247667, U.K., India. Electronic address: dr.binagupta@gmail.com.
authors.forename: Bina
authors.initials: B
authors.lastname: Gupta
mesh_terms: D001564:Benzo(a)pyrene / Q000032:analysis* / Q000528:radiation effects; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D005290:Ferric Compounds / Q000032:analysis / Q000737:chemistry*; D058085:Iron Compounds / Q000032:analysis; D013058:Mass Spectrometry; D008903:Minerals / Q000032:analysis; D019815:Oxalic Acid / Q000737:chemistry; D010782:Photolysis; D012989:Soil Pollutants / Q000032:analysis* / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D005290:Ferric Compounds; D058085:Iron Compounds; D008903:Minerals; D012989:Soil Pollutants; C473845:akaganeite; C094886:goethite; C000499:ferric oxide; D001564:Benzo(a)pyrene; D019815:Oxalic Acid
keywords: Benzo[a]pyrene; Degradation; HPLC–MS; Iron oxides; Metabolites; Remediation