Uwalnianie Cu, Pb i Zn z gleb silnie zanieczyszczonych pod wpływem kwasów mineralnych

The main aim of the paper was to estimate the mobility of heavy metals Cu, Pb and Zn from polluted soilstreated with diluted mineral acids: HCl and a mixture of HNO₃ and H₂SO₄. Soil samples collected from the vicinity of copper smelters, and containing 19 - 1080 mg Cu/kg, 10 - 383 mg Pb/kg and 27 - 118 mg Zn/kg, were incubated with 0,01 mol acid for 1 - 30 days. Only small amounts of metals were released from soils into solutions: 0,01 - 0,40 mg Cu/kg, 0,01 - 0,08 mg Pb/kg and 0,01 - 0,09 mg Zn/kg, which proved a high affinity of metals to solid phase. However, very high amounts of metals were mobilised from soils under the conditions which affected a solid phase: solution equilibrium, such as mixing, high solution to soil ratio and a presence of competing cations Ca and K. The highest amounts of metals released from soils by 0,1 mol HCl, usually mixed with 1 mol KCl, after 24 hs shaking at solution to soil ratio of 25:1 were: 75 - 97% of total Cu, 44 - 97% Pb and 18 - 45% Zn. The conclusion can be reached that batch extraction of metals from polluted soils gives highly overestimated data on metal mobility and other methods should be examined to determine the risk of metal release from those soils.