title: The use of chlorate, nitrate, and perchlorate to promote crude oil mineralization in salt marsh sediments.
abstract: Due to the high volume of crude oil released by the Deepwater Horizon oil spill, the salt marshes along the gulf coast were contaminated with crude oil. Biodegradation of crude oil in salt marshes is primarily limited by oxygen availability due to the high organic carbon content of the soil, high flux rate of S(2-), and saturated conditions. Chlorate, nitrate, and perchlorate were evaluated for use as electron acceptors in comparison to oxygen by comparing oil transformation and mineralization in mesocosms consisting of oiled salt marsh sediment from an area impacted by the BP Horizon oil spill. Mineralization rates were determined by measuring CO2 production and δ (13)C of the produced CO2 and compared to transformation evaluated by measuring the alkane/hopane ratios over a 4-month period. Total alkane/hopane ratios decreased (~55-70 %) for all treatments in the following relative order: aerated ≈ chlorate > nitrate > perchlorate. Total CO2 produced was similar between treatments ranging from 550-700 mg CO2-C. The δ (13)C-CO2 values generally ranged between the indigenous carbon and oil values (-17 and -27‰, respectively). Oil mineralization was greatest for the aerated treatments and least for the perchlorate amended. Our results indicate that chlorate has a similar potential as oxygen to support oil mineralization in contaminated salt marshes, but nitrate and perchlorate were less effective. The use of chlorate as a means to promote oil mineralization in situ may be a promising means to remediate contaminated salt marshes while preventing unwanted secondary impacts related to nutrient management as in the case of nitrate amendments.
authors: Department of Civil and Environmental Engineering, Texas Tech University, Lubbock, TX, 79409, USA.
authors: Maeghan
authors: M
authors: Brundrett
authors: Department of Geosciences, Texas Tech University, Lubbock, TX, 79409, USA.
authors: Juske
authors: J
authors: Horita
authors: The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, 79409, USA.
authors: Todd
authors: T
authors: Anderson
authors: Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA, 70803, USA.
authors: John
authors: J
authors: Pardue
authors: Department of Civil and Environmental Engineering, Texas Tech University, Lubbock, TX, 79409, USA.
authors: Danny
authors: D
authors: Reible
authors: Department of Civil and Environmental Engineering, Texas Tech University, Lubbock, TX, 79409, USA. andrew.jackson@ttu.edu.
authors: W Andrew
authors: WA
authors: Jackson
mesh_terms: D001673:Biodegradation, Environmental; D002245:Carbon Dioxide / Q000378:metabolism; D002704:Chlorates / Q000378:metabolism*; D019015:Geologic Sediments; D006838:Hydrocarbons / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D010578:Petroleum / Q000378:metabolism*; D059392:Petroleum Pollution; D053833:Wetlands
chemical_list: D002704:Chlorates; D006838:Hydrocarbons; D009566:Nitrates; D010578:Petroleum; D002245:Carbon Dioxide; D010100:Oxygen
keywords: Biodegradation; Chlorate; Crude oil; Deepwater Horizon oil spill; Mineralization; Nitrate; Perchlorate; Salt marshes