绿洲城市交通干道绿化树种重金属富集特征及风险评价OACSTPCD

Six common green tree species in Zhangye traffic road green space(experimental area)and Runquanhu Park green space(control area)were selected as research materials.Inductively coupled plasma method(ICP)was used to determine the contents of heavy metals(Cr,Cd,Pb,Cu,Zn)in roots,bark and leaves of greening tree species,and the heavy metal content,enrichment coefficient(BCF),transport coefficient(TF),Muller soil accumulation index(Igeo)and enrichment factor(EF)in different tissues of green tree species were analyzed.(1)the order of heavy metal content in different tree species was Zn＞Cr＞Cu＞Pb＞Cd,the order of Cr,Cu content was bark＞roots＞leaves,Zn content was bark＞leaves＞roots,and Cd content was roots＞bark＞leaves.(2)The roots of Picea crassifolia had strong enrichment of Cd,the bark of of Picea crassifolia had strong enrichment of Cr and Zn,and ash bark of ash had strong enrichment of Cu.The leaves and bark of elm plum had the strongest ability to transport Cr,the leaves and bark of pine camphor had the strongest ability to transport Zn,and the bark of green tree species had stronger ability to transport heavy metals than the leaves.(3)The surface soil Cd near traffic roads was moderately polluted,and Cr exceeded the screening value and control value of soil pollution risk for construction land.(4)Zn was mainly derived from human activities,while Pb and Cu sources were affected by certain transportation activities.Picea crassifolia,white wax and elm plum can be used as the preferred afforestation trees for heavy metal pollution control of road soil in Zhangye City.