排灌机械工程学报2026，Vol.44Issue(8)：848-855,8.DOI:10.3969/j.issn.1674-8530.26.0028
干密度与含水率影响下生物炭对盐渍土渗透特性的调控机理
Regulation mechanism of biochar on permeability properties of saline soils under effects of dry density and water content
摘要
Abstract
To address the excessively high permeability of saline soils that fails to meet the anti-see-page requirements of landfill cover layers,the mechanisms by which corn straw biochar regulates the permeability of saline soils were systematically investigated.Through variable head permeability tests,the effects of biochar content,dry density,and water content(gravimetric)on the permeability cha-racteristics of biochar-modified saline soil were systematically analyzed.The underlying regulatory mechanism was revealed at the microstructural level by combining scanning electron microscopy(SEM)and mercury intrusion porosimetry(MIP)microscopic testing methods.The results show that both dry density and initial water content can affect the permeability of biochar-modified saline soil.The permeability coefficient decreases with increasing dry density,and the magnitude of this effect is governed by biochar content.The transition in the effect of dry density on the dispersion of permeability coefficient occurs at a biochar content of 5%:at a low dosage,the dispersion decreases with increasing dry density,whereas at a high dosage,it increases with increasing dry density.This is attributed to the fact that at high biocher contents,the biochar particles tend to saturate the effective seepage channels in the soil and form compaction-resistant aggregates with soil particles,thus diminishing the marginal effect of further compaction on reducing the permeability coefficient.As the biochar content increases,the permeability coefficient responds to the initial water content in a continuous manner,changing from a positive correlation to a gradual flattening and then to a negative correlation.Microscopic analysis re-veals that the abundant functional groups on biochar surfaces suppress concentrated salt crystallization via adsorption,while its porous structure provides dispersed nucleation sites for salt crystallization,thereby mitigating salt blockage of the original seepage channels and helping maintain permeability sta-bility.MIP results show that as biochar content increases from 0%to 15%,the macropore volume frac-tion decreases from 62.3%to 41.5%,with a corresponding reduction in pore connectivity.These findings provide a theoretical basis and technical reference for the improved application of saline soils in anti-seepage engineering projects.关键词
盐渍土/生物炭/干密度/含水率/渗透系数/孔隙结构/盐结晶Key words
saline soil/biochar/dry density/water content/permeability coefficient/pore structure/salt crystallization分类
农业科技引用本文复制引用
李明玉,王瑶梦,陈天骄,徐莹莹,张艳星..干密度与含水率影响下生物炭对盐渍土渗透特性的调控机理[J].排灌机械工程学报,2026,44(8):848-855,8.基金项目
国家自然科学基金资助项目(42402291) （42402291）
河南省教育厅重点研究项目(26A610012) （26A610012）
河南省大学生创新创业训练计划省级一般项目(S202511070043) （S202511070043）
