A characterization study of hydraulic conductivity of compacted clay and fine sand treated with landfill leachate and nutrient solution

作者：Tang Qiang; Wang Hengyu^*; Chen Hui; Tang Xiaowu

来源：Electronic Journal of Geotechnical Engineering, 2015, 20(12): 4347-4361.

• Bio-clogging
• Characterization studies
• Compacted clays
• Fine sand
• Hydraulic properties
• Landfill leachates
• Leachates
• Nutrient solution

This paper studies the effect of bio-clogging on hydraulic conductivity of compacted soils used as landfill liners. Landfill leachate contains a large amount of microorganism and bacterial biomass, which was likely to cause bio-clogging in landfill liners. To interpret the effect of bio-clogging on hydraulic property of compacted clay and fine sand, in this study, a series of laboratory-scale hydraulic conductivity tests were conducted. The long term hydraulic conductivities of compacted clay and fine sand were measured with distilled water, landfill leachate and one type of nutrient solution. The test results showed that the hydraulic conductivity of compacted clays permeated with distilled water stabilized at approximately 3.77 ×10-8cm/s, and the hydraulic conductivity of compacted clays permeated with landfill leachate or nutrient solution ranged between 1.1 ×10-8cm/s and 5.22 ×10-9cm/s. Such a significant difference was attributed to the effect of bio-clogging. The microorganism and bacterial biomass reduced the hydraulic conductivity up to one order of magnitude. The results showed that the hydraulic conductivity of the fine sand was also efficiently decreased due to the bio-clogging, however, the high flow rate in the fine sand and the hydrolysis of SiO2destroyed the bio-clogging and enlarged the size of pores and the infiltration paths. This study indicated that the bio-clogging is approximately a feasible method to create low-cost and low-hydraulic conductivity barriers using locally available clayed soils.

• 出版日期2015
• 单位浙江大学