Distribution Of Soil Heavy Metals And Cr Isotope Tracer In Panzhihua Region

Due to the rapid development of urbanization in China,human activities such as mining and mining have led to various types of heavy metals entering the soil in different forms,and eventually enriched in the human body through the food chain.Therefore,soil pollution has become the focus of research.Panzhihua City is a typical mining city in China.Mineral development has brought about outstanding soil pollution problems.Studying the characteristics of heavy metals in the soil around Panzhihua Steel Smelting Plant and chromium tracer isotope tracing and analysis of pollution sources can provide scientific basis for pollution prevention and control work,and has important significance for improving soil environmental quality.In this paper,39 soil samples around the smelter were collected,combined with methods and principles of environmental geochemistry and trace element earth,etc.,systematically studied in terms of soil heavy metal content,occurrence patterns,soil mineral morphology,etc.;The methods and principles of isotope geochemistry are used to study the tracers of chromium isotopes in soil and the analysis of pollution sources.After the above studies,we have reached the following conclusions and understanding:1.Concentration of Ti,Mn,V,Zn,Cr,Cu,Ni,Pb,As,and Cd in surface soil in Sichuan Province exceeds the standard value of soil background value,resulting in surface soil contamination;As,Cr,Cu,Ni,V,Cd and Zn are easily affected by external pollution sources;7 elements of Ti,Cr,Cu,As,Ni,V and Zn are mainly present in the residue state;Mn and Pb are mainly present in the reducible state;There is a weak acid in the soluble and oxidizable state.2.The ecological risk assessment of heavy metals in the surface soil near the smelter shows that there is a strong potential hazard to Cd;there is mild to moderate pollution in Cu,Ni,Pb,V,Cr,Ti,Mn,and Zn;there is slight in As.Pollution.With the increase in the distance between the sampling location and the smelter,the degree of contamination of the surface soil in the study area gradually decreased.The risk assessment of the heavy metal forms in the soil near the smelter shows that the order of the average values of secondary heavy metal phases and primary phases is Cd>Pb>Mn>Zn>V>As>Ni>Cu>Cr>Ti.Cd pollution in the study area is severe;Pb and Mn are moderately polluted;Ti,V,Cr,As,Ni,Cu,and Zn are not contaminated.Cd has a strong hazard to the local ecological environment.3.Fractionation of chromium isotopes exists in the soil samples around the smelter.This fractionation can be attributed to the ore smelting process and the fractional fraction?_sol-gas=1.00005.It was found that the chromium isotope fractions produced in industrial processes can be used in the environment.Tracking;soil Cr is mainly affected by industrial dust,slag,and primary rock,?⁵³Cr value is mainly concentrated in industrial dust end-members;?⁵³Cr value of samples with low Cr concentration shows high dispersion,?⁵³Cr value with Cr concentration in samples with high Cr concentration Increase with the increase;with the increase in distance from the smelter,the effect of slag on the value of?⁵³Cr in soil decreases,and the impact of industrial dust increases;over time,the impact of slag and industrial dust on the surrounding soil is gradually strengthened,the slag The accumulation range gradually increases.The scope of industrial dust diffusion should be controlled and slag accumulation sites away from residential areas should be planned.