4种鸢尾属植物对铅锌矿区土壤中重金属的富集特征和修复潜力

通过野外调查和实地修复铅锌矿污染土壤试验,研究了铅锌矿区排污渠污水及底泥中Pb、Zn、Cu、Cd含量和分布特征以及4种鸢尾属植物马蔺（Iris lactea var.chinensis）、黄菖蒲（Iris pseudacorus L.）、溪荪（Iris sanguinea Donn ex Horn.）、花菖蒲（Iris ensata Thunb.）对Pb、Zn、Cu、Cd的积累能力和土壤修复效率差异。结果表明,离污染源越近,重金属污染越严重。Pb、Zn、Cu、Cd4种重金属均大部分沉积在排污水渠的底泥中,污水中Pb严重污染,超标达120倍,底泥中Pb、Zn、Cu、Cd质量分数分别超标1.5倍、1.7倍、1.6倍和1.7倍。排污渠岸土壤Pb、Zn、Cu、Cd质量分数也明显超过了国家规定的土壤环境质量Ⅱ级标准1～5倍。种植4种鸢尾属植物后,土壤中Pb、Zn、Cu、Cd质量分数有所降低。其中,种植马蔺1个月后土壤Pb、Cu、Cd修复效率分别为8.13%、2.45%和22.3%。黄菖蒲和花菖蒲对Zn的修复效率相对较高。4种鸢尾属植物中马蔺对Pb、Cd的吸收能力最强,马蔺地上部（叶、茎）Pb质量分数达983mg·kg-1,且转运系数大于1,是一种潜在的Pb积累植物,黄菖蒲、溪荪和花菖蒲对Zn的吸收能力较强,且吸收的重金属主要积累在根系。

Accumulation of heavy metals in four species oflris L.growing on contaminated soils by Pb-Zn mine and their phytoremediation potential

Field investigation and phytoremediation experiment were carried out in contaminated soils by Pb-Zn mine to analyze the concentration of heavy metals（Pb,Zn,Cu and Cd） in sewage and sediment,accumulation ability and remediation efficiency of Iris lactea var.chinensis,Iris pseudacorus L.,Iris sanguinea Donn ex Horn,and Iris ensata Thunb.The results indicated that more serious heavy metal pollution was found in the investigation site closer from polluted sources.Most of Pb,Zn,Cu and Cd were deposited in the sediment of sewage drains.In comparison with the environmental quality standard for surface water,the concentration of Pb in the surface water of the sewage drains was 120-folds higher than the benchmark value of the IV grade surface water,Pb,Zn,Cu and Cd concentrations in the sediment were 1.5,1.7,1.6 and 1.7-folds higher than the standard values.Furthermore,Pb,Zn,Cu and Cd concentrations in the bank soils of sewage drains were 1-5 folds higher than environmental quality standard.However,the heavy metals concentration decreased after transplanting Iris L plants.One month after transplanting,phytoremediation efficiencies of Iris lactea var.chinensis seedlings on Pb,Zn,Cu and Cd were 8.13%,2.45% and 2.3%,respectively.Phytoremediation efficiencies of Iris pseudacorus L.and Iris ensata Thunb to Zn were relatively higher than the other metals.The accumulation abilities of Iris lactea var.chinensis to Pb and Cd were higher than the other plant species,Pb concentration in the shoot reached 983 mg·kg-1 DW and the translocation coefficient was higher than one,which suggested that Iris lactea var.chinensis was a potential Pb accumulator plant species.Zn accumulation abilities of Iris pseudacorus L.,Iris sanguinea Donn ex Horn,and Iris ensata Thunb were higher,and Zn mainly located in the roots.