煤矸石回填塌陷区重金属淋溶迁移时空规律  

Research on spatiotemporal patterns of heavy metal leaching and migration in coal gangue backfill subsidence area

作　　者：冯印成 赵康 田向勤 马超 聂晶磊 胡华龙 FENG Yin-cheng;ZHAO Kang;TIAN Xiang-qin;MA Chao;NIE Jing-lei;HU Hua-long(Solids Waste and Chemicals Management Center,Ministry of Ecology and Environment,Beijing 100029,China)

机构地区：[1]生态环境部固体废物与化学品管理技术中心,北京100029

出　　处：《中国环境科学》2025年第3期1422-1430,共9页China Environmental Science

基　　金：国家自然科学基金资助项目(52374138);国家重点研发计划资助项目(2024YFC3909301);黄河流域生态保护和高质量发展联合研究资助项目(2022-YRUC-01-0306)。

摘　　要：以陕西省某市煤矸石回填塌陷区协同生态治理示范试验项目为例,探讨煤矸石作为塌陷区回填材料对回填区域环境污染风险,分析重金属淋溶迁移时空规律.利用Hydrus-1D模拟了回填区域煤矸石淋溶后的重金属在土壤中的迁移时空变化规律及过程,并通过土柱实验实测值与模拟值进行对比验证,得到其在不同时间段的入渗距离和在不同土层的浓度平衡时间关系.结果表明,建立的模型可有效模拟该回填区域重金属在土壤中的迁移变化规律;随着时间的推移,重金属淋溶浓度随着深度改变有所不同,为Cr(Ⅵ)=Pb>Ni>Hg,最大迁移距离分别为21.60,21.60,20.70和16.20m.在不同土层深度下,重金属的淋溶浓度大小为Pb>Cr(Ⅵ)>Ni>Hg,浓度趋势呈先快速升高后逐渐平缓的状态,均未超过限值,煤矸石回填塌陷区基本无环境污染影响.The collaborative ecological governance demonstration test project in the coal gangue backfills subsidence area of a city in Shaanxi Province provided an example for this study.This research investigated the environmental pollution risks in the backfill area,where coal gangue was used as the backfill material.It analyzed the spatiotemporal laws of heavy metal leaching and migration.The variation and processes of heavy metals in the soil were simulated using Hydrus-1D.A comparison of measured values from the soil column experiment with the simulated values verified the model,and the analysis identified relationships between infiltration distances at different periods and concentration equilibrium times in various soil layers.The results demonstrated that the established model effectively simulated the migration and change patterns of heavy metals in the soil of the backfill area.Over time,the leaching concentrations of heavy metals varied with depth,ranked as Cr(Ⅵ)=Pb>Ni>Hg,with maximum migration distances of 21.60,21.60,20.70 and 16.20m,respectively.At different soil layer depths,the leaching concentrations of heavy metals followed the order Pb>Cr(Ⅵ)>Ni>Hg.The concentration trends increased rapidly and stabilized,with none exceeding the limit values.The findings confirmed no significant environmental pollution impacts occurred in the coal gangue backfill subsidence area.

关 键 词：煤矸石 重金属 土壤污染 溶质迁移 生态环境 

分 类 号：X53[环境科学与工程—环境工程]