Geostatistical technique was used to predicted spatial reduction of metal contamination after applying EDTAbased soil remediation. Soil samples from 268 locations in the Meza Valley, Slovenia with Pb and Zn concentrations up to 8955 and 15518 mg kg−1 were extracted with the chelating agent ethylenediamine tetraacetate (EDTA). On average, 63 and 22% of Pb and Zn, respectively, were removed with washing solution containing 60 mmol EDTA per kg of soil and 75 and 34% of Pb and Znwith 120 mmol EDTA kg−1 soil. Spatial structure analysis revealed a good spatial structure and little spatial variation of data, which were further interpolated using Empirical Bayesian kriging to produce a continuous surface of Pb and Zn concentrations before and after remediation. Geostatistical simulations showed that the contaminated area covers 19.4 km2 and that soil remediation (60 mmol EDTA kg−1) has the potential to reduce the areawith Pb and Zn above the critical regulatory threshold limit by 91 and 42%, respectively. Validated by pilot-scale remediation trials, soil extractions exhibit little scaledependency of extraction efficiency. EDTA extraction also significantly reduced the bio-accessibility of toxic metals that remained in the soil after remediation using the unified bio-accessibility method. Pb and Zn concentrations accessible from the simulated intestinal phase were reduced by up to 99 and 96%, respectively.
COBISS.SI-ID: 7831161
Lead, zinc, cadmium, arsenic and other potentially toxic metals are naturally present in the environment. Throughout Mežiška valley the contamination of soil due to past mining, smelter and metal manufacturing is noticed. From Javor on SE to Ludranski vrh on S Koprivna and Topla on W and Jazbina in the NE, Koprivna on N and Jazbina on W 179 samples of soil were collected and analyzed using X-ray fluorescence spectroscopy. For lead, the critical value is exceeded by up to 15 times, the zinc to 10 times, for cadmium to 3-fold and arsenic up to 20 times. Map of soil pollution with Pb was constructed using Empirical Bayesian kriging.
COBISS.SI-ID: 3339686