EFFECTS OF COAL GANGUE HILL ON HEAVY METAL POLLUTION CHARACTERISTICS AND SOIL ENZYME ACTIVITIES IN FARMLAND SOILS

In order to understand the heavy metal pollution of a coal gangue hill in Qufu city on the surrounding farmland soil and its effect on soil enzyme activity, the contents of seven heavy metal elements Cr, Pb, Hg, Zn, Cu, Ni and Cd, as well as the activities of catalase, dehydrogenase, sucrase, invertase and urease were determined by sampling points around the coal gangue hill. The pollution characteristics and ecological risks of heavy metals in this area as well as their effects on enzyme activities were evaluated. The results show that the average contents of Cr, Pb, Hg, Zn, Cu, Ni and Cd are 85.951, 57.714, 17.847, 111.986, 51.699, 50.197 and 1.748 mg/kg respectively. A variety of evaluation methods show that Hg exceeds the standard seriously, which is the main pollutant in the region, Cd is the secondary pollutant, and other heavy metals have not reached the pollution level, thus causing little ecological impact. LSD multiple comparison results show that with the increase of distance around the coal gangue pile, the enzyme activity difference is significantly different, which shows that the existence of the coal gangue pile has an impact on the soil enzyme activity, and this impact is different for different enzymes. Through correlation analysis, the enzyme activity has a significant correlation with Hg and Cd, but not with Cr, Zn, Cu and Ni, indicating that Hg and Cd are the main heavy metal elements that affect the enzyme activity of the soil in this region.