title: Biodiesel presence in the source zone hinders aromatic hydrocarbons attenuation in a B20-contaminated groundwater.
abstract: The behavior of biodiesel blend spills have received limited attention in spite of the increasing and widespread introduction of biodiesel to the transportation fuel matrix. In this work, a controlled field release of biodiesel B20 (100L of 20:80 v/v soybean biodiesel and diesel) was monitored over 6.2years to assess the behavior and natural attenuation of constituents of major concern (e.g., BTEX (benzene, toluene, ethyl-benzene and xylenes) and PAHs (polycyclic aromatic hydrocarbons)) in a sandy aquifer material. Biodiesel was preferentially biodegraded compared to diesel aromatic compounds with a concomitant increase in acetate, methane (near saturation limit (≈22mgL-1)) and dissolved BTEX and PAH concentrations in the source zone during the first 1.5 to 2.0years after the release. Benzene and benzo(a)pyrene concentrations remained above regulatory limits in the source zone until the end of the experiment (6.2years after the release). Compared to a previous adjacent 100-L release of ethanol-amended gasoline, biodiesel/diesel blend release resulted in a shorter BTEX plume, but with higher residual dissolved hydrocarbon concentrations near the source zone. This was attributed to greater persistence of viscous (and less mobile) biodiesel than the highly-soluble and mobile ethanol in the source zone. This persistence of biodiesel/diesel NAPL at the source zone slowed BTEX and PAH biodegradation (by the establishment of an anaerobic zone) but reduced the plume length by reducing mobility. This is the first field study to assess biodiesel/diesel blend (B20) behavior in groundwater and its effects on the biodegradation and plume length of priority groundwater pollutants.
authors.affiliation: Federal University of Santa Catarina, Department of Sanitary and Environmental Engineering, Florianópolis, Santa Catarina, Brazil.
authors.forename: Débora Toledo
authors.initials: DT
authors.lastname: Ramos
authors.affiliation: Federal University of Santa Catarina, Department of Sanitary and Environmental Engineering, Florianópolis, Santa Catarina, Brazil.
authors.forename: Helen Simone Chiaranda
authors.initials: HSC
authors.lastname: Lazzarin
authors.affiliation: Department of Civil and Environmental Engineering, Rice University, MS-317, 6100 Main St, Houston, TX 77005, USA.
authors.forename: Pedro J J
authors.initials: PJJ
authors.lastname: Alvarez
authors.affiliation: Environmental Microbial Genomics Group, Laboratoire Ampère, CNRS UMR5005, Ecole Centrale de Lyon, Université de Lyon, Ecully, France.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Vogel
authors.affiliation: Federal University of Santa Catarina, Department of Sanitary and Environmental Engineering, Florianópolis, Santa Catarina, Brazil.
authors.forename: Marilda
authors.initials: M
authors.lastname: Fernandes
authors.affiliation: Petróleo Brasileiro Petrobras, Research Centre (CENPES), Rio de Janeiro, Rio de Janeiro, PO Box 21941598, Brazil.
authors.forename: Mário
authors.initials: M
authors.lastname: do Rosário
authors.affiliation: Federal University of Santa Catarina, Department of Sanitary and Environmental Engineering, Florianópolis, Santa Catarina, Brazil. Electronic address: henry.corseuil@ufsc.br.
authors.forename: Henry Xavier
authors.initials: HX
authors.lastname: Corseuil
mesh_terms: D001673:Biodegradation, Environmental; D056804:Biofuels / Q000032:analysis; D004784:Environmental Monitoring; D060587:Groundwater / Q000737:chemistry*; D006841:Hydrocarbons, Aromatic / Q000032:analysis / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D014877:Water Pollution, Chemical / Q000032:analysis*
chemical_list: D056804:Biofuels; D006841:Hydrocarbons, Aromatic; D014874:Water Pollutants, Chemical
keywords: BTEX; Biodegradation; Biodiesel; Groundwater; Natural attenuation; PAHs