Multimedia Environmental Behavior And Ecological Risk Assessment Of Typical Heavy Metals In The Ebinur Lake Basin

In March 2018,the 13 th session of the National People’s Congress recorded the content of the construction of ecological civilization as a historical amendment to the "Constitution Amendment of the People’s Republic of China." and ecological civilization construction was integrated into economic construction,political construction,cultural construction,and social construction,etc.The whole process provides a powerful guarantee for the great rejuvenation of the Chinese nation.The Ebinur Lake Basin is the most important energy channel in Xinjiang.It is the Western Bridgehead of the New China-Europe Continental Bridge and is also one of the regions in Xinjiang where the economy is rapidly developing.Due to human development in the basin,agricultural and industrial activities and the continuous development of pollutants Emissions caused serious environmental pollution in the Ebinur Lake basin,resulting in continuous accumulation of heavy metals in soils,water bodies,and sediments in the watershed,leading to the deterioration of the ecological environment.In recent years,there have been many environmental pollution phenomena in the Ebinur Lake basin.This article focuses on and studies the pollution of heavy metals.In this thesis,the content of seven heavy metal elementsmercury(Hg)、septum(Cd)、lead(Pb)、copper(Cu)、zinc(Zn)、chromium(Cr)and nickel(Ni)in each environmental phase,the migration between media and the trend of change in the region are studied by using the equal concentration model.At the same time,the potential ecological risk index method and the analytic hierarchy process were used to evaluate the ecological threat factors in the region.Furthermore,the content and potential ecological risk of pollutants in each phase were predicted,and the transformation pathway of typical heavy metal elements in the study area was determined.The results of the study are as follows:1)In general,the predicted value of the model is in good agreement with the measured value,that is,the model is established reasonably and can be applied to pollutant multi-media environmental behavior.The average logarithmic residuals of Zn in heavy metals,water,soils,sediments,and plant facies are the largest when using the equivalent concentration model,and the average logarithmic residuals of Pb are the smallest,and the model calculation results are averaged in the water phase.The logarithmic residual is 1.11,and the element whose calculated logarithmic residual is significantly larger in the aqueous phase is Zn(5.28),The variance of Zn element is derived from the reason that the required parameters are overestimated when estimating the direct emission,and the biggest cause of the average logarithmic residual difference in the water phase is the error caused by the depth of water phase.2)The important way for heavy metal pollutants to enter the multi-media environment is the atmospheric source discharge process,followed by the water advection process.The degradation process of heavy metal pollutants is mainly manifested in the degradation of the plant phase and the degradation of heavy metals in the soil phase.The migration of heavy metals into the sedimentary facies in the study area is the most important environmental migration process.The concentration of Zn in the aqueous phase is relatively large,and the content of Cd is slightly lower than that of other heavy metals.Ni and Hg are mainly distributed in the plant facies,Cd is mainly distributed in the water body,Pb is mainly distributed in the sediment and soil,and Cr and Cu mainly exist in the atmosphere.Taking Cr as an example to study the interphase degradation,it was found that the degradation process mainly occurred in the soil phase(41%)and the plant phase(56%);the sampling depth had the greatest impact on the results of sedimentary facies.3)Using the potential ecological risk index method to evaluate,Cd single elemen t in the soil phase(159.00)and the sediment phase(109.67)pollution risk is in a str ong pollution level,while in the water is in a slight pollution level;the results of si mulation data Similar to the experimentally measured results.Based on the comprehen sive analaysis,the experimentally measured data showed that the risk level of heavy metals in the soil is strong,the risk grade in sediments is moderate,and the risk lev el of heavy metals in the water is slight.The simulation results show that the risk gr ade in the soil is very strong;the water phase in the remaining two phases is of me dium grade.Cd contributed the most to the comprehensive potential ecological risk in dex in the study area,49%;followed by Hg and 46%.There is no significant differe nce between the model simulation results and the actual measurement results.Similarly,the contribution rate of Cd is the largest,followed by Hg.4)The weights of Pb in hazard weights are larger,followed by Cd,and the order of weights is Pb>Cd>Hg>Cu>Cr>Zn>Ni.The weights of Pb in heavy metal weights are larger.Followed by Cr,the order of weights of heavy metal elements is Pb>Cr>Zn>Cd>Hg>Ni>Cu.Based on this,we can see that Pb poses the greatest threat to the environment in the environment.Therefore,when it comes to the management of the environment,we should focus on strengthening Pb prevention and control measures.5)Heavy metals have the most obvious migration ability in soil-cotton.Cotton has the strongest absorption ability for Pb,and Zn in sediment-cotton.At the same time,it can also be seen from the side that the migration of Pb and Zn in the sediment and soil phases is also strong.