Comprehensive evaluation of soil heavy metal distribution characteristics and soil quality in coalfield fire area

In this study, the soil physical and chemical properties and the distribution of heavy metals in the coalfield fire area were analyzed and evaluated, and the soil environmental quality in the coalfield fire area was comprehensively evaluated, so as to provide a theoretical and scientific basis for the comprehensive management of soil environmental quality in the coalfield fire area of Xinjiang. The pH、SOM,、TN、TP、K+、Ca2+、Na+、Mg2+、CO32-、HCO3-、Cl- 、SO42-and total heavy metals Pb、Ni、Cd、Cr、Cu、Zn、As、Hg were measured. The results showed that the average values of Pb, Ni, Cd, Cr, Cu, Zn, As and Hg were 17.24, 29.08, 0.18, 62.67, 34.68, 83.38, 8.45 and 0.06 mg/kg, respectively. The maximum exceedance multiple of Hg element was 10.15 times, the number of points exceeding the standard was 37, the point over-standard rate was 90.20%, and the average over-standard multiple was 1.78. There were 2 soil samples with a single factor pollution index of 0.7-1, which belonged to the alarmed soil, and 39 soil samples with a single factor pollution index of 1-2, which belonged to the lightly polluted soil, and the proportion of the alert soil and the lightly polluted soil were 4.88% and 95.12%.