摘要
本研究以南岭国家公园生态保护区内的某大理岩采石场废弃地为对象,通过成土母质剖面、土壤水平剖面、河流底积物、年轮地球化学及砷超富集植物的系统调查,揭示矿山重金属元素在表生地球化学作用的迁移富集规律,圈定矿区环境重金属潜在生态危害影响范围,重塑矿区重金属元素污染历史,探索历史遗留矿山生态修复。结果表明:1)该历史遗留矿区存在重金属As超高富集,土壤As含量达2893μg/g,超出国家风险筛选值约115倍、管制值约30倍。2)基于潜在生态危害系数,圈定的矿区重金属污染物影响范围由矿区采坑沿小坑河流域至1.5 km外的河漫滩DP03点位附近,高砷矿石在此处河漫滩淤积后,重金属元素的潜在生态危害影响降低。3)矿山污染历史显示,在矿山未开采和开采前期,矿山地形地貌景观尚未被破坏,对周围环境影响极小,重金属含量处于低水平阶段;矿山成规模开采期,重金属开始迁移和污染富集,在开采高峰期,重金属As、Pb等含量也随之达到峰值;矿山停止开采后,由于地表地貌景观未恢复,高砷矿石碎屑仍继续迁移富集,重金属污染也始终处于较高状态。研究表明,该矿山As高富集成因主要为矿区矿石开采开挖后,高砷含量的矿石地表暴露,随地表径流迁移富集导致。蜈蚣草是矿区原生优势种,可在高砷背景下存活,建议通过种植蜈蚣草,提升矿区复绿植物的存活率,实现矿山景观复绿。
In this study,the waste land of a marble quarry in northern Guangdong was taken as the object.Based on the study of the characteristics of element supergene geochemical processes in the weathering-transport-deposition process,the soil parent material profile,soil horizontal profile,river sediments,dendrochemistry and heavy metal hyperaccumulators were systematically investigated.The migration and enrichment process characteristics of heavy metal elements in supergene geochemical processes were studied.The potential ecological risk of heavy metals in the mining area were delineated.The genetic sources and migration pathways of heavy metal elements were identified.The pollution history of heavy metal elements in the mining area was reshaped,and the ecological restoration of historic abandoned mines was explored.The results show that:1)The heavy metal As was highly enriched in the historical mining area,and the soil As content of 2893μg/g,exceeding the national risk screening value by about 115 times and the control value by about 30 times.2)Based on the potential ecological hazard coefficient,the impact range of heavy metal pollutants in the mining area is delineated from the mining pit along the Xiaokeng River basin to the vicinity of the DP03 point on the floodplain 1.5 km away.After the high arsenic ore is deposited on the floodplain at this location,the potential ecological hazard impact of heavy metal elements is reduced.3)The history of mine pollution shows that before and during the early stages of mining,the terrain and landscape of the mine have not been destroyed,with minimal impact on the surrounding environment and low levels of heavy metal content;During the period of large-scale mining,heavy metals begin to migrate and accumulate pollution.During the peak mining period,the content of heavy metals such as As and Pb also reaches its peak;After the mine stopped mining,due to the unrecovered surface landscape,high arsenic ore debris continued to migrate and accumulate,and heavy metal pollution remained at a high level.Research has shown that the high arsenic content in the mine is mainly due to the surface exposure of high arsenic ore after mining and excavation,which is caused by the migration and enrichment of surface runoff.As a native dominant species in mining areas,Pteris vittata can survive in high arsenic backgrounds.It is recommended to plant Pteris vittata to improve the survival rate of green plants and achieve landscape greening in mines.
作者
贺美峄
刘子宁
窦磊
莫滨
贾磊
赵立波
赵艺
HE Mei-yi;LIU Zi-ning;DOU Lei;MO Bin;JIA Lei;ZHAO Li-bo;ZHAO Yi(Southwest Forestry University,Kunming 650000,China;Guangdong Geological Survey and Research Institute,Guangzhou 510080,China)
出处
《环境生态学》
2025年第11期169-176,共8页
Environmental Ecology
基金
广东省地质勘查与城市地质专项(2022-21)资助。
关键词
历史遗留矿山
重金属元素
年轮地球化学
超富集植物
生态修复
Historic abandoned mines
heavy metal elements
dendrochemistry
hyperaccumulation plants
ecological restoration
