title: Effect of soil and a nonionic surfactant on BTE-oX and MTBE biodegradation kinetics.
abstract: The biodegradation kinetics of BTE-oX and MTBE, mixed all together, in the presence of 905 mg/L VSS of BTEX-acclimated biomass was evaluated. Effects of soil and Tergitol NP-10 in aqueous samples on substrate biodegradation rates were also evaluated. Biodegradation kinetics was evaluated for 36 hours, every 6 hours. MTBE biodegradation followed a first-order one-phase kinetic model in all samples, whereas benzene, toluene and ethylbenzene biodegradation followed a first-order two-phase kinetic model in all samples. O-xylene biodegradation followed a first-order two-phase kinetic model in the presence of biomass only. Interestingly, o-xylene biodegradation was able to switch to a first-order one-phase kinetic model when either soil or soil and Tergitol NP-10 were added. The presence of soil in aqueous samples retarded benzene, toluene and ethylbenzene removal rates. O-xylene and MTBE removal rates were enhanced by soil. The addition of Tergitol NP-10 to aqueous samples containing soil had a positive effect on substrate removal rate in all samples. Substrate percent removals ranged 77-99.8% for benzene, toluene and ethylbenzene. O-xylene and MTBE percent removals ranged 50.1-65.3% and 9.9-43.0%, respectively.
authors.affiliation: Laboratorio de Biorremediacion Ambiental, Facultad de Medicina, UANL, Monterrey, NL, Mexico. kaskar@fm.uanl.mx
authors.forename: K
authors.initials: K
authors.lastname: Acuna-Askar
authors.forename: M V
authors.initials: MV
authors.lastname: Gracia-Lozano
authors.forename: J F
authors.initials: JF
authors.lastname: Villarreal-Chiu
authors.forename: J G
authors.initials: JG
authors.lastname: Marmolejo
authors.forename: M T
authors.initials: MT
authors.lastname: Garza-Gonzalez
authors.forename: B
authors.initials: B
authors.lastname: Chavez-Gomez
mesh_terms: D001555:Benzene Derivatives / Q000378:metabolism*; D001673:Biodegradation, Environmental; D007700:Kinetics; D008738:Methyl Ethers / Q000378:metabolism*; D008962:Models, Theoretical; D011060:Poloxalene / Q000378:metabolism*; D012987:Soil / Q000032:analysis*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013501:Surface-Active Agents / Q000378:metabolism*
chemical_list: D001555:Benzene Derivatives; D008738:Methyl Ethers; D012987:Soil; D012989:Soil Pollutants; D013501:Surface-Active Agents; C043243:methyl tert-butyl ether; D011060:Poloxalene