干旱区生态环境知识资源中心(Arid): Experimental investigation on methane advection and diffusion in geosynthetic clay liners

Arid

DOI	10.1016/j.geotexmem.2020.10.018
	Experimental investigation on methane advection and diffusion in geosynthetic clay liners
	Wang, Qiao; Xie, Haijian; Wu, Jiawei; Zhan, Liangtong; Qiu, Zhanhong
通讯作者	Xie, HJ (corresponding author), Zhejiang Univ, Coll Civil Engn & Architecture, 866 Yuhangtang Rd, Hangzhou 310058, Peoples R China.
来源期刊	GEOTEXTILES AND GEOMEMBRANES
ISSN	0266-1144
EISSN	1879-3584
出版年	2021
卷号	49 期号:2 页码:442-451
英文摘要	Geosynthetic clay liners (GCLs) are widely used in landfill and heap-leach facility cover system for mitigating rainfall infiltration and gas migration into atmosphere. Laboratory tests were conducted to investigate methane diffusion and advection through GCLs. Gas permeability coefficient of GCL for the case with moisture content = 47.5% is one and two orders of magnitude greater than the cases with moisture content = 68.5% and 80.9%, respectively, when 20 kPa vertical stress was applied. The batch adsorption tests indicated that adsorption of methane onto bentonite is negligible. The concentration variation for the adsorption of methane onto bentonite can be neglected. However, methane concentration decreased by 14.2% for the test of methane adsorption onto GCL during the first 2-3 days. This is because methane was adsorbed by the geotextiles rather than by the bentonite in GCL. The large porosity and surface area of geotextiles provide lots of micropores for methane adsorption. Analytical model was then developed to analyze the performance of GCL-based liners system with respect to methane transport. The results indicate that methane emission fluxes for the case with SL + GCL are 7.8 and 5.1 times less than the cases with SL + CCL when the moisture contents were 25.9% and 35.1%, respectively. The methane emission fluxes for both of the SL + GCL and SL + CCL can be neglected when they are fully saturated. GCL is recommended to be used in arid and semi-arid regions rather than CCL. GCL is recommended to be used in arid and semi-arid areas rather than CCL. Advection plays a more important role in methane migration through SL + GCL and SL + CCL than that of diffusion. With moisture contents = 25.9% and 32%, methane emission flux attributed to advection accounts for more than 90% of the total emission flux for both cases of SL + GCL and SL + CCL. With the increase of moisture content of SL, the effectiveness of SL in reducing methane emission increases. The saved space for using GCL + SL composite cover compared with using a single SL cover is 0.7 m when the moisture content equals 25.9%, which is 0.5 m greater than the case when moisture content equals 32%. GMB plays a dominant role in inhibiting methane migration and reducing methane emission flux. When moisture content equals 25.9%, the methane emission fluxes for SL + GMB + GCL and SL + GMB + CCL are 343 times and 2643 times less than the cases with SL + GCL and SL + CCL, respectively.
英文关键词	Geosynthetics GCL Methane Diffusion coefficient Permeability coefficient Adsorption
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000615201100003
WOS类目	Engineering, Geological ; Geosciences, Multidisciplinary
WOS研究方向	Engineering ; Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/347935
作者单位	[Wang, Qiao; Xie, Haijian; Wu, Jiawei; Zhan, Liangtong] Zhejiang Univ, Coll Civil Engn & Architecture, 866 Yuhangtang Rd, Hangzhou 310058, Peoples R China; [Wang, Qiao; Xie, Haijian] Zhejiang Univ, Ctr Balance Architecture, Hangzhou, Peoples R China; [Qiu, Zhanhong] Taizhou Univ, Coll Civil Engn & Architecture, Taizhou, Peoples R China
推荐引用方式 GB/T 7714	Wang, Qiao,Xie, Haijian,Wu, Jiawei,et al. Experimental investigation on methane advection and diffusion in geosynthetic clay liners[J],2021,49(2):442-451.
APA	Wang, Qiao,Xie, Haijian,Wu, Jiawei,Zhan, Liangtong,&Qiu, Zhanhong.(2021).Experimental investigation on methane advection and diffusion in geosynthetic clay liners.GEOTEXTILES AND GEOMEMBRANES,49(2),442-451.
MLA	Wang, Qiao,et al."Experimental investigation on methane advection and diffusion in geosynthetic clay liners".GEOTEXTILES AND GEOMEMBRANES 49.2(2021):442-451.