State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
Health and Environmental Sciences, Dow Corning Corporation , Auburn, Michigan 48686, United States.
Environ Sci Technol. 2015 Oct 6;49(19):11527-35. doi: 10.1021/acs.est.5b03197. Epub 2015 Sep 14.
Cyclic methylsiloxane standards (D4, D5, and D6) and linear methylsiloxanes (L3 through L16) were detected with high total concentrations (from 5.20 × 10(4) to 1.07 × 10(6) ng/g dw) in 18 oil sludge samples collected from the Shengli oilfield during 2008-2013. In 306 soil samples from this oilfield, the mean concentrations (43.4-125 ng/g dw) and the detection frequencies (65-76%) of D4-D6 were 10.9-11.9 and 2.05-2.24 times higher than those in reference soil samples, respectively. The concentrations of total cyclic siloxanes (ΣCyclic) had positive correlations (R(2) = 0.79, p < 0.05) with the total petroleum hydrocarbons concentration (TPH) in soil, indicating that oil production could release cyclic siloxanes to the environment. During 2008-2013, an increasing tendency (mean of 13.4% per annum) of ΣCyclic was found in soil with high TPH (>5000 mg/kg) but was not found in soil with lower TPH. Elimination experiments showed that petroleum hydrocarbons could reduce the degradation and volatilization rates of D4, D5, and D6 in impacted oilfield soil. The half-lives of D4, D5, and D6 in the opened and capped soil systems with TPH = 400-40 000 mg/kg were 1.19-22.2 and 1.03-7.43 times larger than those in common soil (TPH = 80 mg/kg), respectively. Furthermore, the petroleum hydrocarbons could affect the rearrangement-reaction rates of D5 and D6 in soil.
在 2008-2013 年期间，从胜利油田采集的 18 个油泥样本中检测到高浓度的环状甲基硅氧烷标准品（D4、D5 和 D6）和线性甲基硅氧烷（L3 至 L16），浓度范围为 5.20×10(4)至 1.07×10(6)ng/g dw。在该油田的 306 个土壤样本中，D4-D6 的平均浓度（43.4-125ng/g dw）和检测频率（65-76%）分别比参考土壤样本高 10.9-11.9 倍和 2.05-2.24 倍。总环状硅氧烷（ΣCyclic）的浓度与土壤中石油总烃（TPH）呈正相关（R(2) = 0.79，p < 0.05），表明采油会向环境中释放环状硅氧烷。2008-2013 年，在 TPH（>5000mg/kg）较高的土壤中，ΣCyclic 呈上升趋势（年均增长率为 13.4%），而在 TPH 较低的土壤中则没有发现这一趋势。消除实验表明，石油烃可降低受污染油田土壤中 D4、D5 和 D6 的降解和挥发速率。在 TPH = 400-40000mg/kg 的开放式和密闭式土壤系统中，D4、D5 和 D6 的半衰期分别是普通土壤（TPH = 80mg/kg）的 1.19-22.2 和 1.03-7.43 倍。此外，石油烃还会影响土壤中 D5 和 D6 的重排反应速率。
