有機液體對土壤電阻特性之影響研究

Abstract

由於國內近年來石化工業發展，加油站日益增多，使地下油槽及管線因□損，內盛液體滲漏的機會大增；再加上有害事業廢棄物最終處理方式以陸地掩埋居多，使附近的居民易因土壤及地下水污染而使身體健康受損的機會增加。 本研究希望藉由量測土壤電阻，與有機液體在土壤中的飽和度，了解該地遭受有機液體污染的程度。並釐清有機液體對土壤-水不連續電導之影響。另外，黏土因有機液體的極性低，不易與陽離子水合，不利於擴散雙層的發展，故希望藉由水和有機溶液間不同混合比例，了解擴散雙層傳導現象。 本研究的試驗結果顯示：以電阻觀點而言，有機液體存在土壤中的機制與孔隙是相同的；另外，以相同濃度的KBr及CdCl2又作為孔隙液體時，以CdCl2為孔隙液體時的試體電阻率較低；在固定含水量下，土壤的電阻率隨著孔隙比增加；在固定孔隙比下，則隨著含水量增加而增加。

In the last few decades, Taiwan’s the petroleum industry underwent rapid development. In the meantime, the number of gasoline stations almost doubled in the last five years. As a result, accidental spills and leakage of petroleum products have occurred much more often. In addition, the lack of control in waste management processes lead to a large number of pollution of soil and ground water. Therefore, there are growing demands for better and faster methods to investigate and to remediate the contaminated sites. In order to understand the relationship between the organic liquid contamination and the electrical resistance of soil, a series of laboratory experiments were carried out. The electrical resistivity of soil with various degree of organic liquid saturation was measured. Due to the low polarity of the organic liquids, their molecules are difficult to hydrate with cations. Therefore, the diffuse double layer surrounding clay particles is difficulty to develop. For the purpose of determining the electrical conductivity of diffuse double layer, different proportion of water and organic liquid are mixed to prepare the clay specimens. In addition effect of concentration of cations in the pore water on electrical resistivity has also been investigated. From the experiment results, it is concluded that with respect to the electrical resistivity, the effect of organic liquid occupying the pores in soils is the same as air. As for the effect of cations in the soil water, lower electric resistivity was measured for soil specimens whose pore liquid is the higher concentration. At a particular water content, an increase in void ratio will result in increase in resistivity. Furthermore, at a particular void ratio, an increase in water content will lead to a decrease in resistivity.