Detection of land degradation caused by historical Zn‐Pb mining using electrical resistivity tomography

Abstract

Soil contamination with trace elements in mining areas still remains an urgent research problem due to their negative environmental impact that needs to be assessed. Despite the wide application of the electrical resistivity tomography (ERT) method to different environmental problems, it continually remains methodologically challenging in soil contamination near waste dumps of post‐metal historical mining. The aims of our study were: (1) to validate ERT measurements for detecting soil contamination by trace elements in the vicinity of a waste dump containing post‐processing spoil from Zn‐Pb ore smelting, (2) to determine the extent of soil contamination, and (3) to analyze the mineralogical, physical, and chemical properties of the soils affected. ERT enabled us to study the variability of electrical properties of soils, to locate the area of contamination, and to evaluate its spatial diversity in both. The impact of soil pollution is reflected on ERT cross‐sections in the form of electrical resistivities that decrease with increasing depth and distance from the waste dump. The respective maximum contents of Zn, Pb and Cd in the soils were 28,903, 12,407, and 136 mg kg−1. The total concentration of trace elements in soils was the highest down to a depth of 0.25 m and decreased in the order: Zn > Pb > Cu > Cd > Tl > As > Cr > Ni. The electrical resistivities of the soil samples were negatively correlated with the silty and clayey fraction content (−0.78), specific electrical conductivity (−0.75), total trace element content (−0.67), organic matter content (−0.57), and gravimetric water content (−0.53). The results also indicate that the electrical properties of the topsoil depend directly on the type of mineral components. Hydrated iron sulphates, lead sulphates, water‐bound in aluminosilicates, Fe oxides/hydroxides, and hydrated Fe, Zn, and Pb sulphates present in the soil all decrease its electrical resistivity. Our results show the impact of the mineralogical, physical, and chemical properties of the soils on the measured electrical resistivity and that including this information in the interpretation of ERT results enables non‐invasive detailed determination of soil contamination by trace elements.

Potentially Harmful Elements (As, Sb, Cd, Pb) in Soil Polluted by Historical Smelting Operation in the Upper Silesian Area (Southern Poland)

“…Inefficient enrichment and metal production technologies and waste disposal methods contributed to high soil, water, and atmospheric pollution in Zn, Pb, Cd, Cu, Al, Ni, and other element production [13,14]. Minerals, both ferrous and non-ferrous metals deposited into the soil by mining, can be a source of bioavailable, toxic metal ions for at least 200 years [15,16].…”