Determination Of Trace Elements And Ecological Risk Assessment In The Adjacent Area To Heilongjiang Province And The Inner Mongolia

The area adjacent to Heilongjiang Province and the Inner Mongolia is a middle-high latitude area in China.The nature reserve within the study area is distributed with a large number of freshwater lakes and forests.The area is more disturbed by human activities.Studies have shown that lake sediments are the main enrichment reservoirs for various trace elements;trace element pollution can be transferred to plants through soil enrichment,and humans are enriched in the body due to direct and indirect consumption of plants,and produce humans.Life has a huge negative impact.Therefore,it is of great scientific and practical significance to conduct research on trace element pollution in lake sediments and soil in the study area.In this paper,surface sediment samples and soil samples were taken from the Songnen Plain and the Inner Mongolia.Soil sampling points to determine the content of potential harmful trace elements V,Cr,Mn,Cu,Zn,As,Cd and Pb in each sample,and analyze their spatial distribution characteristics;at the same time,the physical and chemical properties of the samples Measure,compare the background values of the elements in the crust,and combine SPSS20.0 software,through the principal component analysis method and the correlation analysis method in the multivariate analysis method,to analyze the pollution characteristics and sources of trace elements in the study area;use the geoaccumulation index Method,single factor index method and pollution load index method to evaluate the pollution status and environmental quality of potential hazardous trace elements in lake sediments and soil in the study area,and the potential hazard risk analysis method was used Risk assessment.The main findings are as follows:(1)Potential harmful trace element pollution is more common:Cd elements and element As in lake sediments in some nature reserves adjacent to Heilongjiang Province and the Inner Mongolia exceed 4 times the background value in lake sediments,and the remaining elements are not in each lake sediment More than 2 times the background value;Cd and As elements in the study of soil samples exceeded 4-10 times the background value,and the remaining element contents did not exceed 2 times the background value.Quantitative elements have shown significant enrichment in the region.And the content of As element and Cd element in the study area of the Great Hinggan mounatin showed a decreasing trend from south to north.(2)Measurement of physical and chemical properties of samples:The total nitrogen,total phosphorus and total organic carbon in the sediment are already at a certain enrichment level.Compared with the past monitoring results in this area,it indicates that the level of lake eutrophication has increased.The causes of enrichment and pollution of Cd elements in sediments and soil may be caused by industrial sewage and excessive use of phosphorus-containing fertilizers and pesticides in agriculture.(3)Risk assessment:The 9 trace elements in the study area all have different degrees of pollution.The evaluation results of the accumulation index in lake sediments indicate that the As element and Cd element are in a slight accumulation state in individual lakes and the pollution is relatively serious.In the assessment of potential ecological risks in the study area,Longjiang Lake and Xihulu Lake have medium risk levels,and the ecological risk level of Xiaolonghu Lake is slightly lower.The Cd and As elements in the soil samples are already at a certain level of accumulation in the Great Hinggan Mountains area and has a strong potential ecological risk level.