煤矸石基多孔基质对土壤溶质运移的影响
Effect of coal gangue-based porous matrix on soil solute transport
柴春镜 1冯政君 2吴海滨 1史晓凯 3张俊杰 1宋慧平1
作者信息
- 1. 山西大学资源与环境工程研究所,黄河流域资源增效减碳教育部工程研究中心,山西省黄河实验室,山西太原 030006
- 2. 山西大学黄土高原研究所,山西太原 030006
- 3. 山西大地民基生态环境股份有限公司,山西太原 030012
- 折叠
摘要
针对矿区存在的养分贫瘠、干旱缺水、表土缺乏等问题,提出了利用煤矸石制备多孔基质,并选择其作为矿区表土重构材料进行生态修复的思路,以及从溶质运移的角度评估其可行性.通过垂直土柱易混置换试验,研究了煤矸石基多孔基质对土壤中Cl-和Na+运移特征的影响,揭示了多孔基质对土壤孔隙分布、饱和土壤溶质运移的影响规律.结果表明,当多孔基质掺量为10%～30%(体积分数)时,会缩短Cl-和Na+的穿透时间,这是由于少量掺杂的多孔基质与土壤颗粒相互填充,小孔隙数量增加,形成了更为复杂的运移路径及多孔基质对Na+具有较强的吸附性,会延长Cl-和Na+的穿透时间;随着多孔基质添加量的继续增加(>30%),由于多孔基质容重较小,导致饱和导水率增加,反而会逐渐缩短Cl-和Na+的穿透时间.添加30%多孔基质时,出流液中的Cl-和Na+浓度分别降低了1.65%～46.30%和10.12%～32.88%,Cl-和Na+运移方式以对流为主.土壤孔隙分布和土壤对溶质的吸附性是影响溶质运移的主要因素.煤矸石基多孔基质和黄土以体积比为 3∶7混合的复配模式,可以有效减少溶质运移.
Abstract
The proposal was to address the issues of nutrient deficiency,drought,water scarcity,and lack of topsoil in min-ing areas by utilizing coal gangue to prepare a porous matrix.This matrix was then chosen as a substitute material for topsoil in ecological restoration.Furthermore,its feasibility was evaluated from the perspective of solute transport.The impact of coal gangue-based porous matrix on the migration characteristics of Cl-and Na+in soil was investigated through vertical col-umn miscible displacement experiments,revealing the influence patterns of porous matrix on soil pore distribution and sol-ute transport in saturated soil.The results indicated that the penetration time of Cl-and Na+was reduced when the content of the porous matrix ranged from 10%to 30%.It was due to the fact that the porous matrix with a small amount of doping filled the soil particles with one another,resulting in an increase in the number of small pores and the formation of a more com-plex migration path.Moreover,the porous matrix had a strong adsorption capacity for Na+,and thus the penetration time of Cl-and Na+was prolonged.As the addition of porous matrix continued to increase(＞30%),the lower bulk density of the po-rous matrix led to an increase in saturated hydraulic conductivity,which in turn shortened the breakthrough time for Cl-and Na+gradually.The application of 30%porous matrix resulted in a decrement of Cl-and Na+concentrations in the effluent by 1.65%～46.30%and 10.12%～32.88%,respectively.The transport of Cl-and Na+was primarily governed by convection.The distribution of soil pores and the adsorptive properties of the soil were the major factors affecting solute transport.The com-pound mode of mixing coal gangue-based porous matrix with loess at a volume ratio of 3∶7 could effectively reduce solute transport.
关键词
多孔基质/溶质运移/穿透曲线/CDE模型/煤矸石Key words
porous matrix/solute transport/breakthrough curve/CDE model/coal gangue引用本文复制引用
基金项目
国家重点研发计划-政府间国际科技创新合作项目(2023YFE0100700)
山西交控生态研发计划项目(2023-YF3)
山西省基础研究计划-自然科学研究面上项目(202203021221032)
出版年
2024
NETL
NSTL
万方数据