软岩细粒尾矿无土复垦植物修复的生态效应研究  

Study on the Ecological Effects of Soil-less Reclamation Phytoremediation of Fine Grained Tailings of Soft Rock

作　　者：夏令[1] 刘栋 宋少先[1] 周微 朱江 胡勇 XIA Ling;LIU Dong;SONG Shaoxian;ZHOU Wei;ZHU Jiang;HU Yong(School of Resources and Environmental Engineering,Wuhan University of Technology,Wuhan 430070,China;Institute of Science and Technology Development,Wuhan University of Technology,Wuhan 430070,China;Hubei Sanxin Gold and Copper Co.,Ltd.,Daye 435102,China)

机构地区：[1]武汉理工大学资源与环境工程学院,湖北武汉430070 [2]武汉理工大学科学技术发展院,湖北武汉430070 [3]湖北三鑫金铜股份有限公司,湖北大冶435102

出　　处：《金属矿山》2023年第6期220-228,共9页Metal Mine

基　　金：国家自然科学基金项目(编号:32061123009)。

摘　　要：尾矿大量堆存存在安全隐患和环境风险,尾矿无土复垦是一种很有前景的尾矿减量及生态修复方法。在某软岩细粒尾矿场地开展无土复垦研究:选取了紫云英、紫花苜蓿、早熟禾和结缕草4种草本植物,分别在第90 d、180 d对复垦后尾矿的土壤生态效应和重金属环境风险进行评估。研究发现,4种草本植物可用于软岩细粒尾矿的无土植物修复,结缕草使尾矿pH值从7.99降低到7.55;早熟禾对尾矿物理结构改善效果最明显,尾矿表观密度从1.65 g/cm^(3)降低到1.33 g/cm^(3);紫花苜蓿可有效提高尾矿含水率,从7.93%提高到16.54%,并且可以显著提高有机质和速效磷含量,紫云英可显著提高尾矿速效氮含量。4种草本植物对重金属的固定方式主要为根部吸收富集,其中紫花苜蓿对重金属的积累效果最强。植物修复后尾矿中Cu、Zn、Cr的含量分别降低了17.72%、67.74%和57.56%,重金属赋存形态中残渣态的比例提高,提高了重金属的稳定性,降低了环境风险。复垦后植物为土壤提供养分,改善土壤特性,促进了更多微生物的定殖,复垦后的微生物群落结构更加多样,微生物作为土壤碳氮循环的关键驱动力,在提高复垦效果上发挥着重要作用。综上,对软岩细粒尾矿进行土壤改良和原位植物修复是一种非常值得推广的应用模式。A large amount of tailings are stockpiled at sites such as tailings ponds,which have safety hazards and envi-ronmental risks.Soilless reclamation of tailings is a promising method for tailings reduction and ecological restoration.In this study,soilless reclamation was carried out at a fine grained tailings of soft rock site:four herbaceous plants,Astragalus sinicus Linn.,Medicago sativa Linn.,Poa pratensis Linn.and Zoysia japonica Steud.,were selected to assess the soil ecological effects and environmental risks of heavy metals in the reclaimed tailings at day 90 and 180.It was found that the four herbs could be used for soilless phytoremediation of fine grained tailings of soft rock.Zoysia japonica Steud.reduced tailings pH from 7.99 to 7.55;Poa pratensis Linn.had the most significant effect on improving the physical structure of tailings,and the apparent density of tailings was reduced from 1.65 to 1.33 g/cm^(3);Medicago sativa Linn.could effectively increase the water content of tailings from 7.93%to 16.54%,and could significantly increase organic matter and available phosphorus,and Astragalus sinicus Linn.could significantly increase the available nitrogen content of the tailings.The four herbaceous plants were mainly enriched by root uptake for heavy metals fixation,among which Medicago sativa Linn.had the strongest effect on heavy metals accumula-tion.The concentration of Cu,Zn and Cr in the tailings after phytoremediation decreased by 17.72%,67.74%and 57.56%,respectively,and the proportion of residue state in the fugitive form of heavy metals increased,which improved the stability of heavy metals and reduced the environmental risk.Plants provided nutrients to the soil after reclamation,improved soil proper-ties,promoted more microbial colonization,and the microbial community structure was more diverse after reclamation,and mi-croorganisms played an important role in improving the reclamation effect as a key driver of soil carbon and nitrogen cycle.In conclusion,soil improvement and in situ phytoremediation

关 键 词：软岩细粒尾矿 无土复垦 植物修复 微生物群落 重金属 

分 类 号：X53[环境科学与工程—环境工程]