Water/Hydrocarbon Retention Characteristics in Soil

• Main Authors: Huang, Jin-Fu, 黃進富
• Other Authors: Shin-Yu Shan
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/12173206360223830081

碩士 === 國立交通大學 === 土木工程學系 === 84 === Problems involving the contamination of soil and groundwaterby leaky underground storage tranks (LUSTs) and accidented oilspills are being identified more and more in Taiwan. Cleanup actions are beginning to be required by the public to restore the environment. To estimate the volume of the contamination and the effect of cleanup actions cannot be accomplised without having a good understanding of the retention characteristics of water and organics in soil. No matter whether free product pumping or soil vapor extraction is used to remove the organic contaminants from the ground, there remain some contaminants in ground. The amount of the remaining organics depends on the oil/water retention characteristics of the soil. The objective of this study is to use pressure cell technique to determine the effect of soil characteristics on the retention behavior of oil and water in soil. The results of the experiments show that the amount of retained liquids at various suctions increases with the content of fines of soil samples. In the meantime, for the experiments with organic liquid as non- wetting liquids, the amount of water retained in the soil shows a similar trend. In addition, the amount of liquids retained in the soils depends on the interfacial tention between the wetting and the non-wetting fluids. The higher the interfacial tention the more wetting liquids retained in the soil. When the change of the interfacial tension is not large, the retention characteristics in soil influenced by the distribution of pore is more important than the interfacial tension. On the other hand, the results aslo show that the volumetric content of the wetting liquids after suction was released did not increase to that of original value. The result of the study will help the engineers to get a better understanding of the distribution and migration of the origanic liquid in the vadose zone and near the ground water table. Therefore, the engineers can estimate the amount of organic liquids retained in the subsurface more accurately from the characteristics of the soil.