Leaching and fractionation of heavy metals in mining soils amended with biochar

摘要: Abstract Contaminated mining soils might pose risk to the environment due leaching of heavy metals into ground water, especially under acid conditions. Biochar be an option for remediation contaminated soils. The aim this study was evaluate effect soil acidification and biochar (BC) application on Cd, Pb Zn mobility chemical fractionation in two (A B). Fifteen columns per were packed, applying following treatments: soil + 3% BC; acidified soil; BC control soil + CaCO 3 . treatment constituted by original polluted (soil A or produced slow pyrolysis at 700 °C from sugarcane straw. Ten events performed Pb, pH determined each leaching. sequential extraction procedure after finished. fractions evaluated: mobile, exchangeable, bound Mn oxide, OM, Fe oxide residual. In metal very low. increased drastically reduced Cd (57–73%), (45–55%) (46%) concentrations leachate. With it observed that mostly mobile fraction (15–35%) exchangeable (7–38%), mainly (32–70%) OM (31–43%) principally residual (31–68%). Cadmium presented highest index (33–53%) lowest (1–3%), which is related they are soil. Field studies would necessary confirm effectiveness metals’ retention, prior large scale application.