Release characteristics of heavy metals from coal gangue under simulation leaching conditions

There are more than 30 waste dumps in the area around Handan city. These waste dumps contain many harmful metals, which may migrate into the soil by raining water. In order to study the migration mechanism and regularity of the harmful metals, a leaching test of the coal gangues was carried out in the laboratory. The results showed that the metal concentrations dissolved out and the release rate from coal gangue were not only related to the pH value of leachate, but also related to the element concentrations in coal gangues. The concentrations of Cr, Mn, Cu, Zn, Pb and Cd in the filter water and collected rainwater were beyond the limits in the Environmental Quality Standards for third Class Surface Water (GB 15618-1995).