内蒙古包头某铁矿尾矿库生态修复的植物优选研究

【研究目的】植物修复技术因其具有绿色、经济、环保的特点，在矿山生态修复中应用广泛，而调查和筛选矿山周边适应本地生境的植物物种是进行植物生态修复的关键环节。【研究方法】通过野外调查取样和室内分析测试相结合的方法，对内蒙古包头某废弃铁矿尾矿库及周边11种优势植物的重金属含量、重金属迁移富集能力及其上覆土壤重金属特征进行分析研究，以期筛选优良修复植物，为矿区生态修复提供科学依据。【研究结果】该废弃铁矿尾矿库及周边土壤Fe、Mn、Cu、Pb、Zn、Cr、Cd、F含量均远超过河套平原土壤背景值，地累积指数显示污染等级为2～7级，污染程度从轻—中度污染到极强度污染。植物地下部分各元素含量总体上高于地上部分，除Cu外各植物重金属含量大多超出了正常值范围。【结论】沙蒿和独行菜具有富集型植物特征，玉米、狗尾草、虎尾草和拂子茅属于根部囤积型，碱蓬、灰条菜、苍耳、新疆杨和红柳符合规避型植物特征。可根据植物对重金属的吸收和富集特点，科学合理地选择适宜的植物进行矿区受污染土壤植物修复。创新点：研究了废弃铁尾矿库及周边11种优势植物的重金属特征；揭示了优势植物对重金属的吸收机制。

Plant optimal screening for contaminated soil remediation in an iron mining tailing of Baotou, Inner Mongolia

This paper is the result of geological environment survey engineering.[Objective]Phytoremediation technology has been widely used in mine ecological restoration because of its characteristics of green, economic and environmental protection. The investigation and screening of plant species adapted to local habitats around mines is the key link of plant ecological restoration.[Methods]By the method of soil sampling for investigation and laboratory analysis, this work analyzed 11 dominant plants in the abandoned tailing and the surrounding of Baotou, Inner Mongolia. Test the contents of heavy metals, the enrichment and translocation of heavy metals and the contents of heavy metals of the plant root soil, in order to screen fine restoration plants and provide scientific basis for ecological restoration in mining area.[Results]The results showed that the mean contents of Fe, Mn, Cu, Pb, Zn, Cr, Cd, F much higher than the background value of soil in Hetao Plain, geoaccumulation index revealed the pollution level is 2-7, levels of pollution range from mild to moderate pollution to extremely intense pollution. Heavy metal content in plants shows that the content of each element in the underground part of plants is generally higher than that in the aboveground part, the content of heavy metals in most plants exceeded the normal range except for Cu.[Conclusions] Artemisia desertorum and Lepidium apetalum are belong to accumulators, Zea mays, Setaria viridis, Chloris virgata and Calamagrostis epigeios which absorbed a large amount of heavy metals but mainly held in the roots, Suaeda glauca, Chenopodium album, Xanthium sibiricum, Populus alba and Salix microstachya are belong to excluder. According to the absorption and enrichment characteristics of heavy metals in plants, aim to provide reference for the establishment of artificial phytoremediation system in mining areas and the selection of appropriate plant species for the remediation of heavy metal polluted soil in mining areas.Highlights: The heavy metal characteristics of 11 dominant plants in the abandoned iron tailings pond and its surrounding areas were studied. The mechanism of heavy metal uptake by dominant plants was revealed.