哈尔滨市区绿地土壤重金属污染特征及植物富集

Soil Pollution Characteristics by Heavy Metals and the Plant Enrichment in Green Space of Urban Areas of Harbin

采用野外调查与室内试验分析相结合的方法,研究哈尔滨市区不同绿地功能区土壤重金属( Zn,Cu,Cd,Pb) 污染状况和重金属在旱柳等 7 种植物体内富集特征,并进行综合评价。结果表明: 哈尔滨市区绿地土壤 4 种重金属存在不同程度污染,其中以镉污染最为严重,达到了重污染。工业区排放的含锌、铜、镉、铅的废弃物,机动车辆尾气的排放以及轮胎橡胶的磨损等是造成哈尔滨市区土壤重金属污染的主要来源。哈尔滨市区不同绿地功能区土壤重金属污染由重到轻的顺序为工业区绿地 > 市区公路两旁绿地 > 松花江沿岸绿地 > 城市公园绿地 > 农业用地 > 森林与苗圃绿地; 哈尔滨市区主要绿化树种中,小叶杨对锌、铜、镉 3 种重金属富集系数较大,可作为哈尔滨市区土壤重金属污染修复的重点选用树种,红松、旱柳、花盖梨对锌、铜、镉 3 种重金属富集系数其次,可作为备选树种。

The soil pollution situations by heavy metals in various green space functional regions and their enrichment characteristics in seven plant species, including Salix matsudana, were investigated and comprehensively evaluated by means of field survey and laboratory experiment analysis. The results showed that the pollution degree of Zn, Cu, Cd and Pb in Harbin was different. Of the four kind heavy metals, Cd contamination was the heaviest and reached the severe pollution degree. The main source of soil heavy metal pollution in Harbin was derived from waste containing Zn, Cu, Cd and Pb discharged in industrial areas, automotive emission and the tire~ abrasion. The pollution level of green space functional regions gradually decreased in the following order： industrial zone, traffic areas, Songhua River area, urban park area, farm land, forest and nursery land. Among the main urban greening tree species in Harbin, Populus simonii enriched more Zn, Cu and Cd than the other tree species, therefore, P. simonii could be selected as an important species to repair heavy metal pollution soil. The other tree species, such as Pinus koraiensis, S. matsudana and Pyrus ussuriensis, also enriched to some less degree the three heavy metals and thus could be selected as alternative ones for restore the contaminated environment.