Estimation of Vertical Barrier Performance Based on Microbial Improvement

摘要：

　　Sanitary landfilling is nowadays the most common way to eliminate municipal solid wastes.However,the durability of landfill is mainly determined by the anti-seepage property of vertical cutoff walls.As microorganism has proved effective in plugging micro-pores,and greatly enhance the barrier performance of cutoff wall for MSW landfills.In this study,Escherichia coli.was selected for preconditioning towards compacted soil specimens and the hydraulic behaviours of the specimens were evaluated.According to the results,the huge amounts of microbial exopolysaccharides produced by Escherichia coli.encountered in the soil pores and formed a pore plugging,eventually caused 81–95%decrease in the hydraulic conductivity,from the initial value 5.3×10-5–5.6×10-6 cm/s to the stable value 3.1×10-6–2.9×10-7 cm/s(dropped by 1–2 orders of magnitude).The introduction of clay leads to the increase of surface roughness inside the internal pores as well as the diminution of shear forces,resulted in more effective adhesion between microorganism colonization and the surface of the particles.Subsequently,an extensive parametric analysis was conducted by numerical simulation to investigate the transport behaviour of contaminant through vertical cutoff walls.Several decrease of orders of magnitude in the hydraulic conductivity from 1 ×10-8 to 1×10-10 m/s resulted in the dramatical increase of the breakthrough time by 431.2%which revealed that a low hydraulic conductivity was of significance for vertical cutoff walls to achieve desirable barrier performance.

关键词： Landfill Cutoff wall Barrier performance Hydraulic conductivity Contaminant transport Bioclogging

作者: Yu Zhang Lingling Pan Wang Fei Zhu Ning Qiang Tang

作者单位: School of Urban Rail Transportation,Soochow University,Yangchenghu Campus,Xiangcheng District,Suzhou Suzhou Rail Transit Group Co.,Ltd,No.668 Ganjian Road,Suzhou 215004,China

会议类型: 国际会议

会议名称: The 8th International Congress on Environmental Geotechnics(第八届国际环境土工大会)

会议地点: 杭州

会议语种:英文

页码: 300-307

在线出版日期: 2018-10-28（万方平台首次上网日期，不代表论文的发表时间）