EN
Four soil samples were collected in areas adjacent (sanitary zone) to the Głogów Copper Plant (Poland). They were mostly acidic (pH 4.55 - 4.71) and the total varied widely in their total copper content from 17.03 to 44.07 cMc/kg. The basic copper fractions were determined according to McLaren and Crawford sequential extraction method. Copper of the solution (intensity) expressed as the equilibrium activity ratio, ARoCu when Cu was neither gained nor lost (that is DCuo = 0) as well as labile Cu (LCu) was related to the solid soil phase (quantity) considered as the buffering capacity (BCCu) of the given soils were calculated. The Q/I parameters were estimated at two ionic strengths: 0.005 and 0.010M CaCl2. It was found that all parameters depended on the ionic strength and higher values were obtained at 0.010M CaCl2. An adverse case occurred for the energy of replacement of calcium by copper (DF). Soil properties primarily influenced the magnitude of the Q/I parameters and secondly the high levels of exchangeable and labile soil copper. The low affinity of these soils for copper estimated by the Gapon selectivity coefficients (KG) supported this assumption.