Remediation mechanism of contaminated ground by volatile organic compaunds using X-ray CT method

本研究的目的是了解修复LNAPL污染的热流体，如空气和水的机制。本文研制了一种新型的微聚焦X射线计算机断层扫描（MXCT）热空气喷射装置，并进行了热空气喷射实验。并通过图像分析对修复效果进行评价和观察。同时，利用有限元法对注热水引起的孔隙尺度内的传热进行了分析。实验结果和图像分析表明，热空气的注入使液体非牛顿流体的流动性增加，但由于毛细管压力的作用，液体非牛顿流体的流动性被截留，从而阻止了液体非牛顿流体的流动。而热空气注入法可提高LNAPL的挥发效率，进而进行修复。分析结果表明，热传递是通过孔隙尺度的土粒传递进行的。

The objective of this study is to understand the remediation mechanism of LNAPL contamination by heat fluids such as air and water. In this paper, developed a newly hot air injection device for micro fo-cused X-ray Computed Tomography(MXCT) scanner, and conducted the hot air injection experiment. And, it was evaluated and observed the remediation phenomenon by obtained by the Image analysis. Meanwhile, analyzed about heat transfer in the pore scale due to hot water injection by using the finite element method(FEM). From result of experiment and Image Analysis, Fluidity of LNAPL is increased by hot air injection, but it is trapped by capillary pressure, therefore flow phenomenon is prevented. How-ever, volatilization efficiency of LNAPL was increased by hot air injection, and then remediation was proceeded. Result of Analysis indicates that Heat was spread by transmitting the soil particles in pore scale.