Influence of soil density on gas permeability and water retention in soils amended with in-house produced biochar  

作　　者：Ankit Garg He Huang Weiling Cai Narala Gangadhara Reddy Peinan Chen Yifan Han Viroon Kamchoom Shubham Gaurav Hong-Hu Zhu 

机构地区：[1]Department of Civil and Environmental Engineering,Guangdong Engineering Center for Structure Safety and Health Monitoring,Shantou University,Shantou,China [2]Department of Civil Engineering,Kakatiya Institute of Technology and Science,Warangal,India [3]Department of Civil Engineering,King Mongkut’s Institute of Technology Ladkrabang,Bangkok,Thailand [4]Department of Biology Science and Biology Technology,Indian Institute of Technology Guwahati,Guwahati,India [5]School of Earth Sciences and Engineering,Nanjing University,Nanjing,210023,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2021年第3期593-602,共10页岩石力学与岩土工程学报（英文版）

基　　金：The authors would like to acknowledge the National Natural Science Foundation of China(Grant No.41907252);Shantou University Scientific Research Fund(Grant No.NTF17007)

摘　　要：Biochar has been used as an environment-friendly enhancer to improve the hydraulic properties(e.g.suction and water retention)of soil.However,variations in densities alter the properties of the soil ebiochar mix.Such density variations are observed in agriculture(loosely compacted)and engineering(densely compacted)applications.The influence of biochar amendment on gas permeability of soil has been barely investigated,especially for soil with different densities.The major objective of this study is to investigate the water retention capacity,and gas permeability of biochar-amended soil(BAS)with different biochar contents under varying degree of compaction(DOC)conditions.In-house produced novel biochar was mixed with the soil at different amendment rates(i.e.biochar contents of 0%,5%and 10%).All BAS samples were compacted at three DOCs(65%,80%and 95%)in polyvinyl chloride(PVC)tubes.Each soil column was subjected to dryingewetting cycles,during which soil suction,water content,and gas permeability were measured.A simplified theoretical framework for estimating the void ratio of BAS was proposed.The experimental results reveal that the addition of biochar significantly decreased gas permeability kg as compared with that of bare soil(BS).However,the addition of 5%biochar is found to be optimum in decreasing kg with an increase of DOC(i.e.k_(g,65%)>k_(g,80%)>k_(g,95%))at a relatively low suction range(<200 kPa)because both biochar and compaction treatment reduce the connected pores.

关 键 词：BIOCHAR Degree of compaction(DOC) Gas permeability Soil water retention Wettingedrying cycle 

分 类 号：S156[农业科学—土壤学]