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

作　　者：柴春镜 冯政君 吴海滨 史晓凯 张俊杰 宋慧平 CHAI Chunjing;FENG Zhengjun;WU Haibin;SHI Xiaokai;ZHANG Junjie;SONG Huiping(Institute of Resources and Environmental Engineering,Engineering Research Center of Resource Efficiency Enhancing andCarbon Emission Reduction in Yellow River Basin,Ministry of Education of the People′s Republic of China,Laboratory ofShanxi Province for Yellow River,Shanxi University,Taiyuan 030006,China;Institute of Loess Plateau,Shanxi University,Taiyuan 030006,China;Shanxi Dadi Minji Ecological Environment Co.,Ltd.,Taiyuan 030012,China)

机构地区：[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

出　　处：《无机盐工业》2024年第9期107-116,共10页Inorganic Chemicals Industry

基　　金：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)。

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。The proposal was to address the issues of nutrient deficiency,drought,water scarcity,and lack of topsoil in mining 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 ganguebased porous matrix on the migration characteristics of Cl^(−)and Na^(+)in soil was investigated through vertical column miscible displacement experiments,revealing the influence patterns of porous matrix on soil pore distribution and solute 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 complex 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 porous 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 compound mode of mixing coal ganguebased 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 

分 类 号：TQ127.2[化学工程—无机化工]