Leaching characteristics and potential risk assessment of heavy metals Pb-Cd from mining soils in an acid rain environment

To investigate the pollution characteristics of Pb and Cd in mining soil, dynamic leaching tests was conducted to explore characteristics. Pollution evaluated using Risk Index (RI) Assessment Code (RAC). The results showed that under simulated acid rain, soil had a certain buffer capacity, pH value solution varied between 5.0 8.5. Heavy metals release also varied, with highest amount dissolved being 2.27 mgꞏL -1 , while relatively low, is 0.93 −1 . Moreover, heavy larger particle sizes greater propensity for dissolution when subjected rain. BCR extraction revealed initial metal status mostly residual. After leaching, morphology changed drastically, residual state reducing significantly. RAC RI indicated moderate risk different treatment conditions.