Institute of Karst Geology, Chinese Academy of Geological Sciences, Key Laboratory of Karst Dynamics, MNR and GZAR, Guilin 541004, People's Republic of China; International Research Center on Karst under the Auspices of UNESCO, Guilin 541004, People's Republic of China.
Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430074, People's Republic of China.
Sci Total Environ. 2021 Nov 10;794:148717. doi: 10.1016/j.scitotenv.2021.148717. Epub 2021 Jun 29.
In this study, we investigated a fractured karst aquifer polluted by chlorinated hydrocarbons to determine the contamination characteristics of the main hydrocarbon components. The natural attenuation processes of representative components were simulated and forecasted using TMVOC and hydro-chemical components (NO, SO, HCO Cl and δC). The impact of hydrocarbon compounds on the hydro-chemical ions were estimated, and their historical contamination characteristics were also reconstructed. Results showed that the dynamic characteristics of Trichloromethane and 1,1,2-Trichlorethane can indicate those of chlorinated hydrocarbons, where the rate of natural attenuation was observed to decrease with decreasing concentrations of hydrocarbon compounds. Additionally, the long-term variation characteristics in groundwater levels showed that the relatively stable hydrodynamic field conditions enabled the simulation of the natural attenuation processes of chlorinated hydrocarbons. The simulation which also considered the biodegradation processes showed that the use of TMVOC and hydro-chemical parameters may better describe natural attenuation processes. Over 3 years (from 2017 to 2019), the average percentage of biodegradation in the total natural attenuation was estimated to be 88.35%. Similarly, Trichloromethane and 1,1,2-Trichlorethane are forecasted to have no health hazards in 10 and 15 years, respectively. The contribution rates of biodegradation to HCO and Cl in the fractured karst aquifer varied with the concentrations of chlorinated hydrocarbons. Overall, the findings and methods in this work have significant contributions for advancing remediation developments of petroleum hydrocarbons, especially in karst environments that are highly susceptible to contamination.
在这项研究中，我们调查了受到氯化烃污染的断裂喀斯特含水层，以确定主要烃类成分的污染特征。使用 TMVOC 和水化学成分（NO、SO、HCO、Cl 和 δC）模拟和预测了代表性成分的自然衰减过程。评估了烃类化合物对水化学离子的影响，并重建了其历史污染特征。结果表明，三氯甲烷和 1,1,2-三氯乙烷的动态特征可以指示氯化烃的动态特征，自然衰减速率随着烃类化合物浓度的降低而降低。此外，地下水位的长期变化特征表明，相对稳定的水动力场条件使氯化烃的自然衰减过程得以模拟。同时考虑生物降解过程的模拟表明，使用 TMVOC 和水化学参数可以更好地描述自然衰减过程。在 3 年多的时间里（2017 年至 2019 年），估计总自然衰减中生物降解的平均百分比为 88.35%。同样，预计三氯甲烷和 1,1,2-三氯乙烷在 10 年和 15 年内分别不会对健康造成危害。生物降解对断裂喀斯特含水层中 HCO 和 Cl 的贡献率随氯化烃浓度的变化而变化。总的来说，这项工作的发现和方法对推进石油烃类的修复发展具有重要意义，特别是在易受污染的喀斯特环境中。
