Effects of biochar on soil water retention curves of compacted clay during wetting and drying

Wong，James Tsz Fung1; Chow，Ka Lai2; Chen，Xun Wen4,5; Ng，Charles Wang Wai1; Wong，Ming Hung3

2022-12-01

10.1007/s42773-021-00125-y

Biochar   影响因子和分区

2524-7867

Compacted clay possesses a low water permeability and has been widely used in geo-environmental facilities such as landfill cover systems. Recent studies revealed the potential applications of compacted biochar-amended clay (BAC) as an alternative landfill cover soil. However, the effects of biochar on the soil water retention curves (SWRCs) of clay at low suction are not known. This study can help fill this knowledge gap by measuring the wetting and drying SWRCs of clay and BAC (20% biochar). Soils were compacted in instrumented soil columns and subjected to a wetting and drying cycle, and soil water content and suction were measured along with the soil depth. BAC was saturated faster when compared with clay. Upon drying, the soil water content of clay at 65 mm depth dropped to almost zero, while about 5% of water was retained in BAC. It showed that biochar increased the soil water retention capacity of compacted clay upon drying. SWRCs showed that biochar-clay composite possesses a higher soil water retention capacity at a low soil suction range (< 1000 kPa) compared with clay alone. It revealed the benefits of using compacted biochar-clay composite as a hydraulic barrier to minimize desiccation-induced cracks and potentially promote its serviceability, especially in arid and semi-arid regions. The composite is also a carbon sink material that can reduce landfill gas emissions and pollutant leaching.

Biochar-clay composite Soil amendment Soil carbon Soil depth Soil suction

SCI

英语

其他

WOS:000744509300001

2-s2.0-85122993244

Scopus

1.Department of Civil and Environmental Engineering,The Hong Kong University of Science and Technology,Clear Water Bay, Kowloon, SAR,Hong Kong
2.Department of Geography,Hong Kong Baptist University,Kowloon Tong, SAR,Hong Kong
3.Consortium on Health,Environment,Education and Research (CHEER),Department of Science and Environmental Studies,The Education University of Hong Kong,Tai Po, SAR,Hong Kong
4.Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control,School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
5.State Environmental Protection Key Laboratory of Integrated Surface Water Groundwater Pollution Control,School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Wong，James Tsz Fung,Chow，Ka Lai,Chen，Xun Wen,et al. Effects of biochar on soil water retention curves of compacted clay during wetting and drying[J]. Biochar,2022,4(1).

Wong，James Tsz Fung,Chow，Ka Lai,Chen，Xun Wen,Ng，Charles Wang Wai,&Wong，Ming Hung.(2022).Effects of biochar on soil water retention curves of compacted clay during wetting and drying.Biochar,4(1).

Wong，James Tsz Fung,et al."Effects of biochar on soil water retention curves of compacted clay during wetting and drying".Biochar 4.1(2022).