Space Distribution And Accumulations In Roadside Trees Of Heavy Metal In Urban Soil Of Urumqi City

Analyzes on foundation of heavy metal content and chemical speciation of heavy metal space distribution in urban soil of Urumqi city, compared with difference from different roadside trees to heavy metal accumulation degree. At the same time, with the aid of relation between the heavy metal and the soil main physics character, analyzed the influence factors to soil heavy metal and the chemical speciation distributes . The results showed that: There are quite change of heavy metals content in the soil sampling of six function areas, contents of heavy metal were much higher than the average value of their backgrounds, in which Pb, Zn, Cr, Cu, Cd, Ni, respectively 3.6 times, 2.3 times, 2.1 times, 1.9 times, 4.5 times, 1 time and 1.3 times of the background value.The explanation as a result of the artificial active influence, heavy metals element has presented the tendency of concentrates in different function areas, Hakanson's Potential Ecological Risk Index was used to assess the Potential Ecological Risk of heavy metals in urban soil of Urumqi city. the results showed that: there are varying degree pollution of heavy metal in soil of different function areas and RI = 175, explained heavy metal pollution is middling, it is necessary to carry on the comprehensive administration.The description statistic of the content of different forms (exchangeable, carbonate, Fe - Mn oxides, organic, residual) of heavy metals showed, except Cd in soil was priority to Fe - Mn oxides , the rest five elements, Pb, Cr, Cu,Zn,Ni were priority to residue form. The sequence of different forms of Cd was bound to Fe - Mn oxides >residue form>bound to carbonate>bound to organic matter form>exchangeable form. The sequence of different forms of Pb, Cr, Cu, Zn ,Ni was residue form> bound to Fe - Mn oxides > bound to organic >bound to carbonate>exchangeable form. At the same time, the proportion of activity form (exchangeable+bound to carbonate+bound to Fe - Mn oxides +bound to organic matter) in total content of six elements was quite different. The proportion of active Cd in total content was highest, and active Cr was lowest.Through the data analysis indicated that the proportion of activity form in total content of heavy metals inindustrial area,business area and traffic area were higher .Through the heavy metal content analysis indicated to on the Urumqi different path 13 kind of roadside trees leaf in that: The leaves of Sambucus chinensis Lindl,poPulus,U.laevis Pall, Water plant,U.densa Litvin had better absorption to heavy metals than those of P.asperata Mast,cv.Atropurpurea-Nana,S. oblata Lindl,var, mongolica Litvin.In the roadside trees planter process the reasonable ecological association (Arbor, shrub, grass unifies) matches, not only enhances the plant to the atmospheric purification degree, moreover increased it to the soil repair ability.