贵州锰矿废渣堆场重金属污染风险评价及草本植物重金属吸收特征

为明确锰矿废渣堆场重金属污染及优势草本植物重金属吸收特征，对贵州省典型锰矿废渣堆场的重金属污染风险进行了评价，并调查研究了锰矿废渣堆场草本植物的类群及重金属吸收特征。共采集优势草本植物18种，隶属11科18属，菊科和禾本科为优势科。对18种草本植物体地上部、地下部及其生长基质中Cr、Ni、Cu、Zn、Cd、Pb和Mn 7种重金属元素进行了测定，结果显示，锰矿废渣堆场重金属污染空间变异较大，Mn污染最严重，其次是Cd，属于Mn、Cd复合型污染。计算了草本植物对7种重金属元素的富集系数、转运系数，并对18种草本植物进行了聚类分析，综合分析了草本植物重金属吸收特征，结果显示，看麦娘对Cd富集系数达22.49，对Cd有较强的富集能力；五节芒、商陆对Cr、Ni具有较强的富集能力和转运能力；风毛菊和夏枯草对锰矿废渣区多种重金属均表现出较强的富集能力和转运能力。研究结果表明，锰矿废渣堆场主要为Mn和Cd污染，矿区本土自然生长的优势草本植物可作为生态修复的首选植物。

An assessment of heavy metal absorption patterns in herbaceous plants and pollution risks in manganese mining areas in Guizhou Province

This research explored the occurrence of heavy metal pollution in manganese mining areas， and quantified the heavy metal absorption characteristics of dominant herbaceous plants in typical manganese mining areas in Tongren County， Guizhou Province， China. Samples of 18 commonly occurring herbaceous plant species belonging to 11 families and 18 genera， together with soil samples were collected. Asteraceae and Poaceae were the dominant families. We determined and analyzed the content of 7 elements （Cr， Ni， Cu， Zn， Cd， Pb， Mn） in plants and their soils or growth substrates. It was found that heavy metal pollution was widespread in manganese mine waste areas， Mn pollution was the most serious， followed by Cd， and it belonged to the compound pollution of Mn and Cd. The enrichment and transport coefficients of 7 heavy metal elements in herbaceous plants were calculated， and cluster analysis was performed on the 18 herbaceous plant species sampled. Alopecurus aequalis has a strong enrichment ability for Cd， with a bioaccumulation factor of 22.49； Phytolacca acinosa and Miscanthus floridulus have strong enrichment and transport capacities for Cr and Ni； Saussurea japonica and Prunella vulgaris showed strong enrichment and transfer ability for various heavy metals. To summarize， Mn and Cd were found to be the main pollutants in manganese mining areas， and the native dominant herbaceous plants have suitable uptake characterisitcs for use in ecological restoration in the manganese mining areas.