Investigation And Analysis On Heavy Metal Pollution Of Soil In Anningqu County Of Urumqi Suburb

Soil as an essential component of the ecosystem,also play an indispensable position in the social environment and human life.Soil systems can also provide basic safeguards for daily agricultural industry activities.In this study,the effects of Cu,Zn,Cd,As,Cr,Ni,Pb and Hg on soils in Anningqu area of northern suburb of Urumqi were investigated.And the spatial distribution of heavy metals in the soil was studied.The environmental quality of soil heavy metals was evaluated by using the secondary standard of soil environmental quality(pH> 7.5)and the background value of soil elements in Xinjiang.The results were as follows:(1)Compared with the secondary standard value of national soil environmental quality,only the contents of As and Cd in the eight kinds of heavy metals in farmland were higher than this limit,and the exceeding rate was 6% and 1%.Compared with Xinjiang soil background value,in addition to As other than the other seven elements of the content of 1.5 times higher than the background value,8 kinds of heavy metal elements have exceeded the standard range of 60%-99%;The cumulative trend is more significant,indicating that there are external sources of input in the study area,and these eight kinds of heavy metals in the soil there is a certain accumulation.(2)the main ingredient analysis of eight kinds of metal elements in Anningqu District,8 kinds of heavy metal elements can be divided into three categories,Zn,Cu,Ni as a class,the distance between the three elements is close,the homology between the elements is strong;Hg,As as a class;Pb and Cd are a class,the distance between the two elements is close,has Strong homology.The analysis of the four townships in the study area is similar to the above.(3)In the study area,As shows the autocorrelation relation in the obvious spatial range;Cu,Ni,Cr and Cd block ratio is greater than 75%,in the spatial scale is a weak correlation,subject to greater human impact.Zn,Pb and Hg elements are meso-related in the spatial scale,which is mainly affected by human factors and soil natural factors.(4)The distributions of Cu,Zn,Ni and Cr are similar,and the points with high(5)content are distributed in the industrial commercial mixing area and the concentrated area of the village.The low content is located in the vegetable growing area far away from the villages and towns.Pb and Cd are similar in distribution,and the high content of Pb is distributed in the area where vegetables are concentrated and near the factory.Hg and As in the 40 townships and QingGeda Township,the distribution of large or caused by sewage irrigation.(5)The single factor pollution index of eight heavy metal elements in the study area was Hg> Cd> Zn> Ni> Cu> Cr> Pb> As,and the single factor pollution index of Hg reached 4.68,The lowest level of pollution,is still at a clean level;the remaining six elements are in mild pollution.(6)The average pollution index of soil heavy metals in the study area is 3.70,which belongs to heavy pollution.The study area of the four townships,LiuShihu townships in a slight pollution level,QingGeda Township,SiShihu townships and Anningqu town for heavy pollution level;(7)The average ecological risk index of eight heavy metals in the surface soil was as follows: Hg> Cd> As> Ni> Cu> Pb> Cr> Zn,Cd was in moderate ecological hazard,Hg was very Strong ecological hazards,the other six elements for the slight ecological hazards,Hg on the ecological risk of the study area the highest rate of contribution.The comprehensive ecological risk index(RI)of the study area is301.66,and the soil in the study area is strong ecological hazard.