Abstract:
This data was collected during a 28 day laboratory shaker flask weathering study conducted in the Response and Chemical Assessment Team (RCAT) Laboratory on the LSU Baton Rouge Campus in the Department of Environmental Sciences during the fall of 2012. 40% evaporatively (by mass) weathered Deepwater Horizon reference oil (MC252 collected through a riser vent pipe from the damaged wellhead of Deepwater Horizon drilling rig in the Gulf of Mexico on May 20, 2010) as well as with dispersant (DoR 1:20, Corexit 9500A, Batch # SC0E 2290, donated by NALCO) and without dispersant was placed into shaker flasks and filled with both natural seawater (containing the natural consortia of microorganisms associated with the Northern Gulf of Mexico) and artificial seawater (Instant Ocean mixed with sterilized filtered water) to determine the difference in the weathering profiles of specific crude oil compounds in a well-mixed, controlled environment. This data is used in the publication Olson, G.M.; Gao, H.; Meyer, B.M.; Miles, M.S.; Overton, E.B. (2017). Effect of Corexit 9500A on Mississippi Canyon crude oil weathering patterns using artificial and natural seawater. Heliyon, 3, 3, e00269. doi:10.1016/j.heliyon.2017.e00269.
Suggested Citation:
Ashton-Meyer, Buffy. 2017. Oil/Dispersant Weathering Study – Natural vs. Artificial Seawater, Fall 2012. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7PC30T9
Data Parameters and Units:
File: R4.x264.000-0052_Olson RCAT Weathered Oil Lab Study_sub 1.xlsx Worksheet: Alkanes Parameter Descriptions: Individual Alkane concentrations (ng/mg) for all normal alkanes starting at nC10 through nC35, for seven time periods in each of four experimental treatments OAS ng/mg: OAS=Oil in Artificial Seawater OASD ng/mg: OASD=Oil in Artificial Seawater with Dispersant ON ng/mg: ON=Oil in Natural Seawater OND ng/mg: OND=Oil in Natural Seawater with Dispersant; Day (0,0.5,3,7,14,21,28): Day refers to the time at which samples and replicates were sacrificed. All Day 0 samples for each treatment were sacrificed immediately after completion of swirling flask procedure; all Day 0.5 samples for each treatment were on the orbital shaker and sacrificed after 12 hours; and, so forth. Total Alkanes (ng/mg): total concentrations for all normal alkanes starting at nC10 through nC35 for seven time periods in each of four experimental treatments Stdev: Standard deviation of the replicates for each sampling event Worksheet: PAHs Parameter Descriptions: Individual PAH concentrations (ng/mg) for parent and alkylated PAHs beginning with Naphthalene and going through Chrysene, for seven time periods in each of four experimental treatments OAS ng/mg: OAS=Oil in Artificial Seawater OASD ng/mg: OASD=Oil in Artificial Seawater with Dispersant ON ng/mg: ON=Oil in Natural Seawater OND ng/mg: OND=Oil in Natural Seawater with Dispersant Day (0,0.5,3,7,14,21,28): Day refers to the time at which samples and replicates were sacrificed. All Day 0 samples for each treatment were sacrificed immediately after completion of swirling flask procedure; all Day 0.5 samples for each treatment were on the orbital shaker and sacrificed after 12 hours; and, so forth. Total Aromatics (ng/mg): total concentrations for parent and alkylated PAHs beginning with Naphthalene and going through Chrysene, for seven time periods in each of four experimental treatments Stdev: Standard deviation of the replicates for each sampling event Worksheet: Alkanes and Reduction Parameter Descriptions: Alkanes (ng/mg): total concentration of all targeted alkanes (i.e., sum of all targeted alkanes) for seven time periods in each of four experimental treatments, 3 replicates per treatment % Alkane Reduction: the reduction of alkanes expressed as a percentage for each replicate in four treatments, across all sampling points (Day 0 to Day 28) Delta Conc: changes in alkane concentrations from Day 0 and each sampling point (i.e., Alkane Concentration for Day 0 - Alkane Concentration for Day 0.5); all sampling points are subtracted from Day 0. Avg % Alkane Reduction: the replicate average % alkane reduction for each sampling point Stdev: standard deviation for the corresponding Avg % Alkane Reduction Worksheet: PAHs and Reduction Parameter Descriptions: PAHs (ng/mg): total concentration of all targeted PAHs (i.e., sum of all targeted PAHs) for seven time periods in each of four experimental treatments, 3 replicates per treatment % PAH Reduction: the reduction of PAHs expressed as a percentage for each replicate in four treatments, across all sampling points (Day 0 to Day 28) Delta Conc: changes in PAH concentrations from Day 0 and each sampling point (i.e., PAH Concentration for Day 0 - PAH Concentration for Day 0.5); all sampling points are subtracted from Day 0. Avg % PAH Reduction: the replicate average % PAH reduction for each sampling point Stdev: standard deviation for the corresponding Avg % PAH Reduction Worksheet: c17pris c18phyt Parameter Descriptions: Ratios of nC17 to Pristane: Dimensionless ratio of the conc. of normal alkane C17 to the branched alkane Pristane (nC17/Pris), for seven time periods in each of four experimental treatments, 3 replicates per treatment Ratios of nC18 to Phytane: Dimensionless ratio of the conc. of normal alkane C18 to the branched alkane Phytane (nC18/Phy), for seven time periods in each of four experimental treatments, 3 replicates per treatment Worksheet: D2P2 D3P3 Parameter Descriptions: Ratios of C2-Phenanthrenes to C2-Dibenzothiophenes: Dimensionless ratio of the conc. of 2 Methyl (C2) Phenanthrenes to the 2 Methyl (C2) Dibenzothiophenes (P2/D2), for seven time periods in each of four experimental treatments, 3 replicates per treatment Ratios of C3-Phenanthrenes to C3-Dibenzothiophenes: Dimensionless ratio of the conc. of 3 Methyl (C3) Phenanthrenes to the 3 Methyl (C3) Dibenzothiophenes (P3/D3) Worksheet: Summary Biomarker Scores Parameter Descriptions: Ratio of Selected Biomarkers (Tri- and Pentacyclic Triterpanes, Rearranged and Regular14α(H)- and14β(H)-Steranes, and Triaromatic Steroids): Dimensionless ratio of the relative peak heights of various biomarker compounds to other biomarker compounds, m/z 191, 217, 218, and 231 Percentage of Biomarker ratios that match fresh MC252 source oil, %: Fresh MC252 = 100% based on a set of 22 biomarker ratios. All oil residues were compared to the same 22 biomarker ratios and a matching percentage was created. i.e. 19(sample)/22(Fresh MC252) = a score of 86%)
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