文献类型：期刊文献

英文题名：Performance of a compacted loess/gravel cover as a capillary barrier and landfill gas emissions controller in Northwest China

作者：Zhan, Liang-tong Li, Guang-yao Jiao, Wei-guo Lan, Ji-wu Chen, Yun-min Shi, Wei

第一作者：Zhan, Liang-tong

通信作者：Li, GY[1]

机构：[1]Zhejiang Univ, Dept Civil Engn, MOE Key Lab Soft Soils & Geoenvironm Engn, Hangzhou 310058, Peoples R China;[2]Guizhou Inst Technol, Sch Civil Engn, Guiyang 550003, Peoples R China;[3]Xian Solid Waste Management Off, Xian 710000, Peoples R China

第一机构：Zhejiang Univ, Dept Civil Engn, MOE Key Lab Soft Soils & Geoenvironm Engn, Hangzhou 310058, Peoples R China

通信机构：corresponding author), Zhejiang Univ, Dept Civil Engn, MOE Key Lab Soft Soils & Geoenvironm Engn, Hangzhou 310058, Peoples R China.

年份：2020

卷号：718

外文期刊名：SCIENCE OF THE TOTAL ENVIRONMENT

收录：;EI(收录号：20200808206846);Scopus(收录号：2-s2.0-85079680320);WOS:【SCI-EXPANDED(收录号:WOS:000526029000100)】；

基金：The authors acknowledge financial support from the National Natural Science Foundation of China (No. 51625805) and the Primary Research and Development Plan of Zhejiang Province (No. 2019C03107).

语种：英文

外文关键词：Loess/gravel capillary barrier cover; Water percolation; Landfill gas emissions; Field measurements; Numerical modeling

摘要：Loess is widely distributed in Northwest China where the rainy season coincides with the warm and vegetation growth period. The use of loess as a capillary barrier cover (CBC) material is promising. However, how the loess/gravel CBC perform as a capillary barrier and landfill gas emissions controller remains elusive. In this study, the performance of a designed CBC comprised 1.3 m-thick compacted loess underlain by 0.3 m-thick gravel in extremely wet and dry years of Xi'an city from 1950 to 2000 was analyzed using numerical modeling. An instrumented CBC test section comprised 0.9 m-thick compacted loess underlain by 0.3 m-thick gravel was constructed to show the hydraulic responses in real conditions from January 2015 to January 2017. The numerical results indicated that the designed CBC performed well as a capillary barrier as no percolation occurred during the extremely wet periods. Despite adopting a CBC of 0.4 m thinner than the designed one, the test section produced only 16.16 mm percolation during the two-year monitoring period, and that can meet the recommended limit of 30 mm/yr. The effect of the capillary break on increasing the water storage within the CBC was observed at the test section in fall. The increased water storage can significantly decrease the gas permeability, and thus improve the performance of the CBC as a LFG emissions controller. Furthermore, the LFG emissions can be controlled to meet the limit set by the Australian guideline by decreasing the bottom gas pressure and artificial watering. Finally, a procedure was proposed to enhance the performance of CBCs. (C) 2020 Elsevier B.V. All rights reserved.