Huang He, Reddy Narala Gangadhara, Huang Xilong, Chen Peinan, Wang Peiying, Zhang Yuantian, Huang Yuanxu, Lin Peng, Garg Ankit
Department of Civil and Environmental Engineering, Guangdong Engineering Center for Structure Safety and Health Monitoring, Shantou University, Guangdong, 515063, China.
Department of Civil Engineering, Kakatiya Institute of Technology and Science, Warangal, Telangana, 506015, India.
Sci Rep. 2021 Apr 1;11(1):7419. doi: 10.1038/s41598-021-86701-5.
Recent studies on water retention behaviour of biochar amended soil rarely considers the effect of pyrolysis temperature and also feedstock type into account. It is well known that pyrolysis temperature and feedstock type influences the physical and chemical properties of biochar due to stagewise decomposition of structure and chemical bonds. Further, soil density, which is in a loose state (in agricultural applications) and dense (in geo-environmental engineering applications) can also influence water retention behaviour of biochar amended soils. The major objective of this study is to investigate the water retention properties of soil amended with three different biochars in both loose and dense state. The biochars, i.e. water hyacinth biochar (WHB), chicken manure biochar (CMB) and wood biochar (WB) were produced in-house at different pyrolysis temperature. After then, biochars at 5% and 10% (w/w%) were amended to the soil. Water retention behaviour (soil suction and gravimetric water content) was studied under drying and wetting cycle simulated by varying relative humidity (RH, 50-90%). Results show that 10% WHB produced at 300 °C were found to possess highest water retention. CMB is found to possess higher water retention than WB for 10% amendment ratio. In general, the addition of three biochars (at both 300 °C and 600 °C) at 10% (w/w) significantly improved the water retention at all suction ranges in both loose and dense compaction state as compared to that of the bare soil. The adsorption (wetting) and desorption (drying) capacity of biochar amended soils is constant at corresponding RH.
近期关于生物炭改良土壤保水行为的研究很少考虑热解温度和原料类型的影响。众所周知，由于结构和化学键的逐步分解，热解温度和原料类型会影响生物炭的物理和化学性质。此外，土壤密度在松散状态（农业应用中）和致密状态（地质环境工程应用中）也会影响生物炭改良土壤的保水行为。本研究的主要目的是研究用三种不同生物炭在松散和致密状态下改良土壤的保水特性。这些生物炭，即水葫芦生物炭（WHB）、鸡粪生物炭（CMB）和木材生物炭（WB），是在不同热解温度下在内部制备的。然后，将5%和10%（w/w%）的生物炭添加到土壤中。通过改变相对湿度（RH，50 - 90%）模拟干湿循环，研究保水行为（土壤吸力和重量含水量）。结果表明，在300℃制备的10%水葫芦生物炭具有最高的保水能力。对于10%的添加比例，发现鸡粪生物炭比木材生物炭具有更高的保水能力。总体而言，与裸土相比，在松散和致密压实状态下，添加10%（w/w）的三种生物炭（在300℃和600℃）在所有吸力范围内都显著提高了保水能力。生物炭改良土壤的吸附（湿润）和解吸（干燥）能力在相应的相对湿度下是恒定的。
