Geochemical and geophysical indicators of oil and gas wastewater can trace potential exposure pathways following releases to surface waters
Geochemical and geophysical indicators of oil and gas wastewater can trace potential exposure pathways following releases to surface waters
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DOI：
10.1016/j.scitotenv.2020.142909
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发表时间：
2021-02-10
影响因子：
9.8
通讯作者：
Akob, Denise M.
中科院分区：
文献类型：
--
作者：
Cozzarelli, Isabelle M.;Kent, Douglas B.;Akob, Denise M.
由于沉积物-水的相互作用和地下水/地表水的交换，石油和天然气废水的排放可能对河流水质和下游生物产生复杂的影响。以前，钠（Na），氯化物（Cl），钡（Ba），锶（Sr），锂（Li）和微量碳氢化合物的浓度升高被确定为与Sr和镭（Ra）同位素组合时OG废水释放的关键标志。在这里，我们评估了持久性的OG废水泄漏的小溪在北达科他州使用地球化学测量和建模，水文分析和地球物理调查相结合。2015年2月和6月，OG废水占下游站点河水成分的0.1%至0.3%，但在2016年和2017年无法量化。然而，OG-wastewater标记持续在沉积物和孔隙水2.5年后的泄漏和高达7.2公里的泄漏现场下游。OG废水成分的浓度是高度可变的，这取决于水文条件。电磁测量结果表明，在泄漏现场下游7.2公里处渗漏附近的堤岸下，电导率明显较高。地貌调查显示，沉积物的活化是一个重要的污染物传输过程。不稳定的Ba，Ra，Sr和铵（NH 4）的浓度从沉积物中提取的沉积物是一个长期的水库，这些成分，无论是在小溪和河漫滩。使用在这个深入研究的sitewe确定的生态影响的驱动程序，确定了41个流域的北达科他州景观，可能会受到类似的插曲输入OG废水泄漏。OG废物管理活动期间释放到环境中的污染物的影响仍然知之甚少，但是，Ra和Sr同位素组成的分析，以及微量无机和有机化合物的浓度在这些网站的孔隙水提供深入了解潜在的动物和人类的风险以及源补救区之外。(C)2020年，任作家。由爱思唯尔公司出版
Releases of oil and gas (OG) wastewaters can have complex effects on stream-water quality and downstream organisms, due to sediment-water interactions and groundwater/surface water exchange. Previously, elevated concentrations of sodium (Na), chloride (Cl), barium (Ba), strontium (Sr), and lithium (Li), and trace hydrocarbons were determined to be key markers of OG wastewater releases when combined with Sr and radium (Ra) isotopic compositions. Here, we assessed the persistence of an OG wastewater spill in a creek in North Dakota using a combination of geochemical measurements and modeling, hydrologic analysis, and geophysical investigations. OG wastewater comprised 0.1 to 0.3% of the stream-water compositions at downstream sites in February and June 2015 but could not be quantified in 2016 and 2017. However, OG-wastewater markers persisted in sediments and pore water for 2.5 years after the spill and up to 7.2-km downstream from the spill site. Concentrations of OG wastewater constituents were highly variable depending on the hydrologic conditions. Electromagnetic measurements indicated substantially higher electrical conductivity under the bank adjacent to a seep 7.2 km downstream from the spill site. Geomorphic investigations revealed mobilization of sediment is an important contaminant transport process. Labile Ba, Ra, Sr, and ammonium(NH4) concentrations extracted from sediments indicated sediments are a long-term reservoir of these constituents, both in the creek and on the floodplain. Using the drivers of ecological effects identified at this intensively studied sitewe identified 41 watersheds across the North Dakota landscape that may be subject to similar episodic inputs from OG wastewater spills. Effects of contaminants released to the environment during OG waste management activities remain poorly understood; however, analyses of Ra and Sr isotopic compositions, as well as trace inorganic and organic compound concentrations at these sites in pore-water provide insights into potentials for animal and human exposures well outside source-remediation zones. (C) 2020 The Authors. Published by Elsevier B.V.