Determination of Some Heavy Metals in European and Polish Coal Samples

Abstract

This work presents coal analyses for heavy metal content (Tl, Cu, Zn, Cd, Fe). The tested coal samples came from a Russian deposit in the Kuzbass Basin (Novosibirsk and Kemerovo Oblasts, near Kazakhstan) and from Poland. The concentration of thallium in coal was determined using DPASV—differential pulse anodic stripping voltammetry—and other metals were examined with FAAS, i.e., flame atomic absorption spectrometry. The study confirmed the presence of thallium in the tested coal sample. The coal samples from outside the European Union contained four times more thallium (the maximum content of thallium in coal has been determined to be 0.636 mg·kg−1) than the samples of Polish coal (where the maximum content of thallium was 0.055 mg·kg−1). Cadmium concentration was on average 1.99 mg·kg−1 in the samples from outside the European Union, and 1.2 mg·kg−1 in the samples of Polish coal. Zinc concentration in the samples from outside the European Union was on average 11.27 mg·kg−1, and in the samples of Polish coal approx. 7 mg·kg−1. In addition, iron concentration in all coal samples was determined as 14.96 mg·kg−1, whereas copper concentration in the samples from outside the European Union averaged as 3.96 mg·kg−1. The obtained results do not show any correlation between the presence of thallium and the presence of other metals. It is worth noting that heavy metals pose a threat to living organisms due to their persistence and bioaccumulation, particularly in the context of dust emissions to the atmosphere.