Possible pollution of soil and groundwater with potentially toxic metals in the area of Podravina : master's thesis

Predmet istraživanja ovog diplomskog rada su tla s područja Podravskih Sesveta. Cilj rada bio je laboratorijskim istraživanjima odrediti geokemijske karakteristike tla u svrhu karakterizacije potencijalnog onečišćenja tla i podzemne vode s teškim metalima. Laboratorijske analize tla uključivale su: pH, električnu vodljivost (EC), granulometrijski sastav, kapacitet kationske zamjene (CEC), saturaciju bazama, sekvencijsku ekstrakcijsku analizu (BCR) metala te mineralošku analizu difrakcijom na prahu (XRD). Tlo je na lokaciji blago kiselo duž cijelog pedološkog profila. S porastom dubine raste i udio manjih čestica tla. Vrijednosti CEC-a dobro koreliraju sa promjenama u granulometrijskom sastavu. S mineraloškom analizom utvrđen je značajan udio minerala glina što se podudara s granulometrijskom analizom. BCR analizom utvrđeno je kako izmjerene koncentracije metala (Cu i Cr) ne prelaze maksimalno dozvoljene vrijednosti (MDK) propisane Pravilnikom o zaštiti poljoprivrednog zemljišta od onečišćenja (NN 71/19). Ukupne koncentracije arsena (As), cinka (Zn) i nikla (Ni) na pojedinim uzorcima prekoračuju MDK vrijednosti, međutim najveći dio teških metala vezan je u rezidualnoj frakciji što ih čini nedostupnim u trenutnim uvjetima okoliša.The subject of this study were soil profiles from the Podravske Sesvete location. The aim of this study was to determine the geochemical characteristics of soil through preliminary research in order to characterize the possible pollution of soils and groundwaters with potentially toxic metals. Laboratory analyses included pH, electrical conductivity (EC), soil texture cation exchange capacity (CEC), sequential extraction analysis (BCR) of metals and mineralogical analysis using X-ray powder diffraction (XRD). The soil at the location is slightly acidic along with the entire pedological profile. The increase in depth is accompanied by the decrease in size of mineral particles. The CEC values correlate well with changes in the soil texture. Using mineralogical analyses, a significant proportion of clay minerals was determined, which correlates with the soil texture. The BCR showed that the measured concentrations of metals (Cu and Cr) do not exceed the maximum permissible concentrations as defined by the Croatian Ministry of Agriculture (NN 71/19). In some soil samples, the total concentrations of arsenic (As), zinc (Zn) and nickel (Ni) exceed the maximum permissible concentrations (MDK). However this stud has also shown that the most of the investigated toxic metals are bound to the residual fraction, which makes them unavailable in the current environmental conditions