Industrial plants in the eastern part of the Kraków agglomeration as a source of snow-cover pollution

Celem badań było określenie przestrzennego zróżnicowania cech fizykochemicznych wody pochodzącej z pokrywy śnieżnej zalegającej w okolicy kombinatu metalurgicznego ArcelorMittal Poland, położonego we wschodniej części aglomeracji krakowskiej. Próbki śniegu pobrano z 40 punktów znajdujących się w odległości od 2 do 8 km od granicy tego kombinatu. Mineralizacja wody pochodzącej ze stopienia śniegu była około 6 razy wyższa w odległości 2 km od kombinatu niż w odległości 8 km. Odczyn wody w odległości 2 km był zasadowy, natomiast w odległości 8 km – kwaśny. Stężenie większości jonów malało wraz z oddalaniem się od kombinatu. Przestrzenne zróżnicowanie stężenia jonów Ca^{2+} i Mg^{2+} kształtowało się koncentrycznie względem kombinatu, z tendencją do wydłużenia w kierunku wschodnim (pH i F^{-}). W porównaniu do lat 1970. stężenie Ca^{2+}, Mg^{2+} i SO_4^{2-} było niższe o dwa rzędy wielkości.The purpose of the research presented has been to assess the spatial variability to physical and chemical properties of snow cover in the vicinity of the ArcelorMittal Poland steel plant near Kraków, as one of the main sources of air pollution in the Kraków metropolitan area. On March 10th and 11th 2006, snow samples were collected at 40 different sampling sites located within four different distances of the plant. The inner zone consisted of sites located 2 and 4 km away from the steel plant, the outer zone of sites located 6 and 8 km away. Once snow had been melted, its chemical composition was determined using a DIONEX ICS-2000 chromatograph. Snow pH and specific electric conductance (SEC) were also measured using a multi-functional ELMETRON CX-721 meter. Physical and chemical properties were interpolated using an ordinary kriging method. The total concentration of most ions were found to be progressively lower at greater distances from the steel plant. Thus values for total dissolved solids were about six times greater in snow 2 km from the plant as opposed to 8 km away (0.98 v. 0.16 meq·dm^{-3}). Reaction ranged from moderately alkaline (8.54 pH_{max}) at a distance of 2 km to moderately acidic (4.87 pH_{min}) at a distance of 8 km. The concentrations of most ions were lower at greater distances from the plant, and indeed the spatial variability to snow characteristics exhibited a concentric pattern (e.g. for Ca^{2+}, Mg^{2+}), albeit with a tendency towards elongation in an easterly direction (e.g. for pH, F^{-}). However, Cl^{-} and NO_{3}- concentrations were in fact higher at greater distances from the steel plant. Snow from the inner zone was characterized by considerable concentrations of HCO_{3}- and Ca^{2+} ,while that from the outer featured a more diverse chemical composition, with HCO_{3}- and Ca^{2+} concentrations progressively lower at growing distances from the steel plant. Ca^{2+}, Mg^{2+}, and SO_4^{2-} concentrations were nevertheless one or two orders of magnitude lower than those obtained in 1977 and 1978, indicating that today’s steel plant is much less of a polluter than its predecessor of thirty years ago