Low frequency vibration stimulating enhance mobilization of DNAPL in porous media

• Main Authors: Yu-chi Chang, 張聿麒
• Other Authors: Wen Wang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/93225000092787671171

碩士 === 國立聯合大學 === 環境與安全衛生工程學系碩士班 === 97 === Elastic wave stimulation applying for groundwater contamination remediation had shown that the elastic wave can improve the effect of remediation. However, the study of mechanism of elastic wave stimulation enhance mobilization of pollutant in porous media is rare. In this research, the mechanism of low-frequency stimulation in porous media will be force. Two mechanisms had been study: viscosity and permeability. 0.8 mm glass bead and 0.3 mm quartz sand were using as the porous media in the mechanism study. In both porous media, the results of viscosity study of TCE show that the sports viscosity reduction percentage is increasing with vibration frequency, this result can support the theory of Biot (1956) that referred to friction with the medium particles frequency increased. By a period vibration stimulation, the results of permeability study showed that the instantaneous seepage speed of flow increment is increasing with vibration frequency. This mechanism may cause by the residual hydraulic pressure existence and the medium pore decrease which made by the vibration stimulation. By a continuous transformation time stimulate, the results of permeability study showed that the seepage speed of flow reduces in the long time's stimulation. It is possibly causes by the Particle arrangement is reach to stable, so that the infiltration flow rate reduction. By the continuous transformation frequency stimulate, the results of permeability study showed that the seepage flow speed changes at different stimulation frequencies. Then, each stimulus frequency has a specific arrangement of particles which could change the soil formations. It is confirmed that the effect of pollutants mobile mechanism increases with viscosity and permeability change due to elastic wave stimulation in porous media.