The weathering of oil after the Deepwater Horizon oil spill: insights from the chemical composition of the oil from the sea surface, salt marshes and sediments
The weathering of oil after the Deepwater Horizon oil spill: insights from the chemical composition of the oil from the sea surface, salt marshes and sediments
复制标题
DOI：
10.1088/1748-9326/7/3/035302
复制
发表时间：
2012-07-01
影响因子：
6.7
通讯作者：
Wu, Wei
中科院分区：
文献类型：
--
作者：
Liu, Zhanfei;Liu, Jiqing;Wu, Wei
深水地平线（DWH）漏油事件中释放的石油可能对墨西哥湾北部生态系统产生短期和长期影响。需要了解石油的成分和浓度如何因风化（包括化学、物理和生物过程）而改变，以评估石油的毒性及其对墨西哥湾北部生态系统的影响。这项研究检查了从海面和盐沼收集的油慕斯中以及 DWH 漏油后沉积在井口附近沉积物中的石油中的石油碳氢化合物。 2010 年 5 月在两个站（OSS 和 CT，分别距井口 130 公里和 85 公里）采集了油摩丝，并于 2011 年 5 月在距井口 6 公里范围内的 SG 和 SC 站采集了两个沉积物样品。我们还于 2010 年 7 月在距井口 186 公里的密西西比州马什角 (MP) 的盐沼中采集了油摩丝。在这些样品中，正构烷烃， 测量多环芳烃 (PAH)、烷基化 PAH、BTEX（苯、甲苯、乙苯以及对、间和邻二甲苯的统称）、C3-苯和痕量金属，以检查石油的化学变化情况。化学分析表明，油慕斯经历了不同程度的风化，其规律为OSS<CT<MP。这种模式与预计的油慕斯从事故现场到盐沼的运动一致。此外，油慕斯中微量金属Al、V、Cr、Fe、Mn、Ni、Co、Cu、As和Pb的含量在前往盐沼的途中普遍增加，表明这些微量金属可能在运输过程中聚集到油慕斯中。石油碳氢化合物数据显示，在 DWH 石油泄漏一年后，沉积物中沉积的石油仅经历了轻度至中度降解，这得到了短链正构烷烃 (C10-C15)、BTEX 和 C3-苯的存在的支持。沉积物中石油的风化可能是生物降解和溶解造成的，表现为中链正构烷烃 C16-C27 的优先损失、n-C-17/Pr 和 n-C-18/Ph 的比例较低以及 PAH 相对于烷基化 PAH 的优先损失。
The oil released during the Deepwater Horizon (DWH) oil spill may have both short-and long-time impacts on the northern Gulf of Mexico ecosystems. An understanding of how the composition and concentration of the oil are altered by weathering, including chemical, physical and biological processes, is needed to evaluate the oil toxicity and impact on the ecosystem in the northern Gulf of Mexico. This study examined petroleum hydrocarbons in oil mousse collected from the sea surface and salt marshes, and in oil deposited in sediments adjacent to the wellhead after the DWH oil spill. Oil mousses were collected at two stations (OSS and CT, located 130 and 85 km away from the wellhead, respectively) in May 2010, and two sediment samples from stations SG and SC, within 6 km of the wellhead, in May 2011. We also collected oil mousse from salt marshes at Marsh Point (MP), Mississippi, 186 km away from the wellhead in July 2010. In these samples, n-alkanes, polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, BTEX (collective name of benzene, toluene, ethylbenzene and p-, m-, and o-xylenes), C3-benzenes and trace metals were measured to examine how the oil was altered chemically. The chemical analysis indicates that the oil mousses underwent different degrees of weathering with the pattern of OSS < CT < MP. This pattern is consistent with the projected oil mousse movement from the accident site to salt marshes. Also, the contents of trace metals Al, V, Cr, Fe, Mn, Ni, Co, Cu, As and Pb in the oil mousse generally increased along the way to the salt marshes, indicating that these trace metals were perhaps aggregated into the oil mousse during the transport. Petroleum hydrocarbon data reveal that the oil deposited in sediments underwent only light to moderate degradation one year after the DWH oil spill, as supported by the presence of short-chained n-alkanes (C10-C15), BTEX and C3-benzenes. The weathering of oil in sediment may result from biological degradation and dissolution, evidenced by the preferential loss of mid-chained n- alkanes C16-C27, lower ratios of n-C-17/Pr and n-C-18/Ph, and preferential loss of PAHs relative to alkylated PAHs.