Soil Heavy Metal Pollution Of The Outer-ring Greenblet In Shaihai And Heavy Metal Accumulation Capacities Of The Greening Trees

With the vehicle ownership rapid growing,the automobile exhaust has become one of the main sources of heavy metal pollution in cities.In the thesis,the contents of As,Cr and Cu in soil and plants samples taken from 3 sample fields(Xinzhuang multidimensional highway,the crossroad of Wuzhou avenue and Zhaogao road,the crossroad of Yingbin avenue and Tanghuang road)along the outer-ring greeblet of Shanghai city were measured utilized ICP.And the heavy metal pollution situations of the outter-ring greenbelt were evaluated with methods of single factor contaminant index,Nemerow comprehensive contamination index and potential ecological risk index.Meanwhile,the heavy metal accumulation capacities of the greening trees in the sample fields were assessed with biological accumulation coefficient and biological transfer coefficient.The conlusions of the article will provide some suggestion for the road greening and phytoremediation in Shanghai district.The main conclusions were as followed:Both the As,Cr and Cu contents in the soil of Wuzhou road were higher than those of Xinzhuang overpass and Tanghuang road.The maxium concentration of As was 60.60mg/kg,which was measured in the 0-5cm soil layer.While the highest value of Cr and Cu were observed in 5-20 cm soil layer,which reached 485.04 mg/kg and 39.17mg/kg,respectively.Cr contents in the soil of Xinzhuang overpass and Tanghuang Road increased with the soil layer deepening.While Cu contents in Xinzhuang overpass had the opposite trend.In the 3 sample fields,the single factor contamitant indexes of As and Cr were at slight pollution grade;Cu was clean.But the Nemerow comprehensive contamination indexes of the 3 sample fields were all at serious level.Regarding the potential ecological risk index of heavy metals in the soil of the three sample fields,the potential ecological risk of As was in the middle class,while the ecological risk of Cr and Cu was low.The comprehensive potential ecological risk indexes of the 3 sample fields were all at the moderate level,the descending order was Wuzhou Avenue,Xinzhuang overpass and Tanghua Road.In general,the heavy metal pollution situation of Wuzhou avenue was the most serious among the three sample fields.Through integrated analyses of heavy metal content,biological accumulation coefficient and biological transfer coeffient of the greening trees in the sample fields,the plants which could adapt to the moderate heavy metal pollution and higher accumulation capacities were as followed: Bambusa multiplex,Platycladus orientalis),Prunus Cerasifera,Distylium racemosum,Salix babylonica and Cinnamomum camphora.