title: Removal of residual contaminants in petroleum-contaminated soil by Fenton-like oxidation.
abstract: The degradation of bioremediation residues by hydrogen peroxide in petroleum-contaminated soil was investigated at circumneutral pH using a Fenton-like reagent (ferric ion chelated with EDTA). Batch tests were done on 20 g soil suspended in 60 mL aqueous solution containing hydrogen peroxide and Fe(3+)-EDTA complex under constant stirring. A slurry reactor was used to treat the soil based on the optimal reactant conditions. Contaminants were characterized by Fourier transform infrared spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry. The results showed that the optimal treatment condition was: the molar ratio of hydrogen peroxide to iron=200:1, and pH 7.0. Under the optimum condition, total dichloromethane-extractable organics were reduced from 14,800 to 2300 mg kg(-1) soil when the accumulative H(2)O(2) dosage was 2.45 mol kg(-1) soil during the reactor treatment. Abundance of viable cells was lower in incubated Fenton-like treated soil than in untreated soil. Oxidation of contaminants produced remarkable compositional and structural modifications. A fused ring compound, identified as C(34)H(38)N(1), was found to exhibit the greatest resistance to oxidation.
authors.affiliation: School of Material Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen, 333001, Jiangxi Province, China.
authors.forename: Mang
authors.initials: M
authors.lastname: Lu
authors.forename: Zhongzhi
authors.initials: Z
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Qiao
authors.forename: Yueming
authors.initials: Y
authors.lastname: Guan
authors.forename: Meng
authors.initials: M
authors.lastname: Xiao
authors.forename: Chong
authors.initials: C
authors.lastname: Peng
mesh_terms: D001673:Biodegradation, Environmental; D002264:Carboxylic Acids / Q000032:analysis; D004787:Environmental Pollution / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D010084:Oxidation-Reduction; D010578:Petroleum / Q000032:analysis*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D002264:Carboxylic Acids; C045076:Fenton's reagent; D010578:Petroleum; D012989:Soil Pollutants; D006861:Hydrogen Peroxide; D007501:Iron; D009584:Nitrogen; C046170:naphthenic acid