常见绿化树种对重金属的富集效应评价

【目的】研究常见绿化树种对重金属的富集效应评价,为干旱绿洲城市建设绿化植物的选择提供依据。【方法】以常见绿化树种为对象,采用电感耦合等离子体发射光谱仪测定各样品重金属含量,分析不同绿化树种对土壤重金属Cu、Pb、Ni和Zn的富集能力与转运特征,运用隶属函数法对富集转运能力进行综合评价。【结果】根际土壤中Cu、Ni、Pb和Zn含量均值分别为40.27、48.03、29.24和120.77 mg/kg,分别是新疆土壤重金属环境背景值1.51、1.91、1.53和1.76倍;对研究区采用内梅罗综合污染指数评价,该区为轻度污染。树种地下部分重金属含量高于地上部分;对其富集系数与转运系数的计算得,冠榆、红皮云杉对Pb的富集系数与转运系数均大于1,冠榆、红皮云杉对重金属Pb具有超富集效应。【结论】5种常见树种对4种重金属的BTF整体表现为Pb＞Ni＞Zn＞Cu;各树种对重金属Cu、Ni、Pb与Zn的综合转运能力:圆冠榆＞白榆＞红皮云杉＞樟子松＞白蜡。

Evaluation of Enrichment Effect of Common Greening Tree Species on Expressway

【Objective】 Evaluation of Enrichment Effect of Common Greening Tree Species on Expressway To find out the dominant tree species for heavy metal restoration in traffic roads in the hope of providing suggestions for the selection of green plants in arid oasis cities.【Method】 In this study, the common greening tree species on the side of Jingxin expressway in Urumqi were studied. The heavy metal content of each sample was determined by inductively coupled plasma emission spectrometer. The enrichment ability and transport characteristics of heavy metal Cu, Pb, Ni and Zn in soil by different greening tree species were analyzed. A membership function method was used to comprehensively evaluate the enrichment and transshipment capacity.【Results】 The results showed that the average values of Cu, Ni, Pb, and Zn in the rhizosphere soil were 40.27, 48.03, 29.24, and 120.77 mg / kg, respectively, which were 1.51, 1.91, 1.53, and 1.76 times the environmental values of heavy metals in Xinjiang soil. The Nemelo comprehensive pollution index was used to evaluate the study area, which was lightly polluted. Through the analysis of the heavy metal content of the tree species, the heavy metal content of the underground part of the tree species was higher than that of the above-ground part, which indicated that the Ulmus pumila and Picea koraiensis Nakai had a super-enrichment effect on heavy metals Pb.【Conclusion】 According to the analysis, the BTF of the five common tree species to the four heavy metals is Pb＞ Ni＞ Zn＞ Cu; The comprehensive transport capacity of various tree species to heavy metals Cu, Ni, Pb and Zn is: Ulmus densa＞ Ulmus pumila ＞ Picea koraiensis Nakai ＞ Pinus sylvestris var. mongolica ＞ Fraxinus chinensis Roxb.