Influence of Petroleum Deposit Geometry on Local Gradient of Electron Acceptors and Microbial Catabolic Potential

Abstract

A field survey was conducted following the Deepwater Horizon blowout and it was noted that resulting coastal petroleum deposits possessed distinct geometries, ranging from small tar balls to expansive horizontal oil sheets. A laboratory study evaluated the effect of oil deposit geometry on localized gradients of electron acceptors and microbial community composition, factors that are critical to accurately estimating biodegradation rates. One-dimensional top-flow sand columns with 12-hour simulated tidal cycles compared two contrasting geometries (isolated tar "balls" versus horizontal "sheets") relative to an oil-free control. Significant differences in the effluent dissolved oxygen and sulfate concentrations were noted among the columns, indicating presence of anaerobic zones in the oiled columns, particularly in the sheet condition. iv

Effect of drinking water treatment process parameters on biological removal of manganese from surface water

“…Denaturing gradient gel electrophoresis (DGGE) of bacterial 16S rRNA genes was applied to select media samples (as described by Singh et al (2012)) in order to track the fate of the isolates in the columns and compare the overall microbial community composition. Amplified 16S rRNA genes from select samples from Columns B and D were subjected to 454 pyrosequencing (Research and Testing Laboratories, Lubbock, Texas).…”

Environmental effects of the Deepwater Horizon oil spill: A review

“…Although only a minor portion of the DWH oil reached the shoreline, the amount was enough to cause widespread contamination of coastal habitats and ecosystems, including many salt marshes, wetlands and Weathered oil appeared at several beach locations as aggregated oily materials often referred to as tar mats or tar balls, the latter is often referred to as surface residue balls (SRBs). A number of studies have characterized the chemical composition of tar balls collected at different locations and time-points after the DWH oil spill, e.g., (Dalyander et al, 2014;Elango et al, 2014;Hayworth et al, 2015;Kiruri et al, 2013;Mulabagal et al, 2013;Singh et al, 2012;Urbano et al, 2013;White et al, 2014;Wise et al, 2014b;Yin et al, 2015). On AL beaches, the white sand made the oil very visible and prompted various clean-up activities (Hayworth et al, 2011).…”