Biodegradability of Corexit 9500 and Dispersed South Louisiana Crude Oil at 5 and 25 °C

Abstract

The reported persistence of the dioctyl sodium sulfosuccinate (DOSS) surfactant in Corexit 9500 in the oil plumes formed during the Deepwater Horizon oil spill has contributed to concerns regarding the biodegradability and bioavailability of dispersed oil and dispersants used as an oil spill countermeasure in the Gulf of Mexico. We studied the biodegradation of DOSS and dispersed South Louisiana crude oil (SLC) in laboratory microcosms. Two oil-degrading cultures from the Gulf of Mexico were isolated, one from the surface (meso) and one from close to the area of the Macondo well (cryo). Each was enriched on SLC, the former at 25 °C, the latter at 5 °C. Results indicated that the meso culture rapidly and completely degraded DOSS, alkanes, and aromatics. The cryo culture metabolized the same compounds but with a lag of 28 d and a remaining residual of iso-alkanes, n-C(30-35), and the 4-ring PAHs.

Chemical dispersants can suppress the activity of natural oil-degrading microorganisms

“…Biodegradation of anionic surfactant DOSS to α/β-ethyhexylsulfosuccinate (EHSS) occurs under aerobic conditions (37). In the dispersant-only treatment, a significant (P < 0.05) decrease (8%) of DOSS and an increase of EHSS (15%) was observed at T 3 (SI Appendix, Fig.…”

Regioselective Syntheses of [13C]4‐Labelled Sodium 1‐Carboxy‐2‐(2‐ethylhexyloxycarbonyl)ethanesulfonate and Sodium 2‐Carboxy‐1‐(2‐ethylhexyloxycarbonyl)ethanesulfonate from [13C]4‐Maleic Anhydride

“…4 More recently, an EPA group established that ethylhexyl sulfosuccinate (EHSS) monoesters are likewise obtained from the branched sulfosuccinate diester DOSS (1) during its biodegradation by oildegrading microorganisms found in the Gulf of Mexico. 5 As part of an ongoing effort to develop a trace analysis for surfactants and their degradation products associated with Corexit oil dispersants in Gulf of Mexico seawater field and laboratory microcosm samples, 6 we required access to stable isotope mass spectrometric standards of α-EHSS (2) and β-EHSS (3) for quantification of LC-MS/MS experiments. Herein, we report regioselective syntheses of quadruply labelled stable isotope mass spectrometric standards for α-EHSS ([ 13 C] 4 -2) and β-EHSS ([ 13 C] 4 -3) from [ 13 C] 4 -maleic anhydride (4) and prove the regiochemistry of both compounds by 13 C/ 13 C and 1 H/ 13 C NMR spectral correlation experiments.…”

Photo Degradation of Cotnaminants of Emerging concern (CECs) under Simulated Solar Radiation: Implications for their Environmental Fate

“…A more recent study by Campo et al found that DOSS was biodegraded by 98% in 8 and ~38 days in cultures from surface and deep Gulf of Mexico waters (at 25°C and 5°C, respectively) (Campo et al, 2013). In the light of these findings it is important to monitor the DOSS and its degradation products in the environment as the released oil dispersant moves and transforms.…”

“…Despite of its low to moderate toxicity to most aquatic species (George-Ares and Clark, 2000;Hemmer et al, 2010;Judson et al, 2010) and skeptical biodegradation (Kujawinski et al, 2011;Campo et al, 2013), it increases the dissolution of polyaromatic hydrocarbons (PAHs, carcinogens) in aqueous phase (Barron et al, 2003). Moreover in presence of sunlight, a multifold (1.5-48) increase in the toxicity of DOSS dispersed oil was observed in eggs and larvae of Pacific herring (Barron et al, 2003).…”

“…Scheurer et al showed that sucralose was even persistent to advanced treatments employed in wastewater treatment plants including soil aquifer treatment and powdered activated carbon and thus making it a valuable tracer of wastewater intrusions (Scheurer et al, 2011). The data on the biodegradation of DOSS were limited and contradictory (Kujawinski et al, 2011;Campo et al, 2013 portion of their removal in the environment would be by photodegradation.…”