Distribution And Risk Evaluation Of Heavy Metals In Sewage Irrigated Area Of Baoding

Based on the temporal and spatial distributions of heavy metals in soils, the accumulation,pollution risk,potential ecological risk were evaluated in this paper on heavy metals soil in typical region of Baoding city, Hebei province.The whole studies provided the scientific foundation for the soil heavy metal contaminated repair in irrigated areas and the environmental quality evaluation, sustainable development and maintain ecological equilibrium. Mainly the results are as follows :1.It was showed that the Baoding suburbs soil heavy metals content changed with the time increased. In soils of sewage irrigation and controlled zone Pb,Cd content was increased with the time increased. In soils of controlled zone the increased extent of heavy metals content was less than sewage Irrigation. It was the sewage irrigation evocable heavy metals increased extent that the increased extent of heavy metals content of sewage irrigation subtract controlled zone.2.The spatial variations of heavy metals in the soils of baoding irriereated areas. Fields were made definite spatial variations ,using the method of associating Kringe interpolationand GIS,that the distributions of different elements were patchiness,stripped and scattered.3. Research section of the cumulative index calculation metal,of the cumulative index for heavy metal item are greater than 1, From the accumulation, It is differences between heavy metals, The degree sequence of accumulation are for :Zn>Cd>Pb>Cu>Cr>Ni, From range of cumulative index: Zn>Cd>Cu>Pb>Cr>Ni.4. The heavy metals in the soils of Irrigated areas were evaluated using and pollution index.showed that soil have sign of metals in the research , except for Cu, the super background value rate of other heavy metals were high value. And Zn,Pb,Cd are 100%, far greater.In a country two level of standard criteria for evaluating the metal single factor index from the order of Zn>Cd>Ni>Cu>Cr>Pb,In Soil background value of standard criteria for evaluating the metal single factor index from the order of Zn>Pb>Cd>Cr>Ni>Cu, Thus two types of evaluation criteria of all metal single factor is the difference, but two kinds of assessment standards place an order of the biggest factor is Zn element, the former is in gradeâ…¡and with the clean range,the latter of minor contamination. Evaluation of potential ecological risks, The Cd to moderate the ecological hazards levels.5. Through the analysis of pollution indexes of plant samples in soils of sewage irrigation, it educed that content of Pb of cabbage more than international health allow standards and other elements are not exceeded. From the composite pollution index for analysis: the composite pollution index of the seeds of maize 0.5<0.7, it was showed that 5 kinds of heavy metal elements of seeds of maize that all belong to clean condition. It was 1.28 of the composite pollution index for cabbage. It was belonged to light pollution status.