The relationship of total dissolved solids measurements to bulk electrical conductivity in an aquifer contaminated with hydrocarbon
The relationship of total dissolved solids measurements to bulk electrical conductivity in an aquifer contaminated with hydrocarbon
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DOI：
10.1016/s0926-9851(04)00057-6
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发表时间：
2004-11-01
影响因子：
2
通讯作者：
Legall, FD
中科院分区：
文献类型：
--
作者：
Atekwana, EA;Atekwana, EA;Legall, FD
最近的一个概念模型链接较高的体积电导率在碳氢化合物影响的网站更高的总溶解固体（TDS）由于生物降解过程中产生的酸增强矿物风化。在这项研究中，我们评估了上述模型，通过调查的体积电导率，TDS和地下水中的电导率的垂直分布。结果表明，在受污染的地点，TDS较高，与上述模型一致。此外，体电导率和TDS的陡峭垂直梯度表明在该网站的垂直和空间异质性。我们观察到，在流体电导率40 mS/m，体积电导率随着流体电导率的增加而增加。然而，在流体电导率>80 mS/m时，体积电导率增加而流体电导率没有相应增加，导致受污染样品的体积电导率和流体电导率之间的相关性差。这表明，电解质电导率是不完全负责所观察到的体积电导率的变化。我们提出了两个可能的原因，在低的流体电导率和不良的正相关性在高的流体电导率的反比关系：（1）地球化学异质性，由于生物过程中没有捕获的规模可比的体积电导率测量和（2）在表面电导率的变化，符合一个简单的岩石物理模型，表明较高的表面电导率的污染沉积物。我们的结论是，生物降解过程可以影响污染沉积物的电解质和表面导电性能，这两个因素可以解释较高的体积电导率在沉积物中观察到的碳氢化合物的影响。由爱思唯尔公司出版
A recent conceptual model links higher bulk conductivities at hydrocarbon impacted sites to higher total dissolved solids (TDS) resulting from enhanced mineral weathering due to acids produced during biodegradation. In this study, we evaluated the above model by investigating the vertical distribution of bulk conductivity, TDS, and specific conductance in groundwater. The results showed higher TDS at contaminated locations consistent with the above model. Further, steep vertical gradients in bulk conductivity and TDS suggest vertical and spatial heterogeneity at the site. We observed that at fluid conductivities 40 mS/m, bulk conductivity increased with increasing fluid conductivity. However, at fluid conductivities >80 mS/m, bulk conductivities increased without a corresponding increase in fluid conductivity, resulting in a poor correlation between bulk conductivity and fluid conductivity for the contaminated samples. This suggests that electrolytic conductivity was not completely responsible for the observed variability in bulk conductivity. We suggest two possible reasons for the inverse relationship at low fluid conductivity and poor positive correlation at high fluid conductivity: (1) geochemical heterogeneity due to biological processes not captured at a scale comparable to the bulk conductivity measurement and (2) variability in the surface conductivity, consistent with a simple petrophysical model that suggests higher surface conductivity for contaminated sediments. We conclude that biodegradation processes can impact both electrolytic and surface conduction properties of contaminated sediments and these two factors can account for the higher bulk conductivities observed in sediments impacted by hydrocarbon. Published by Elsevier B.V.