The coal-fired Plomin Thermal Power Plant (Plomin TPP) in Croatia is located in the center of the east coast of the Istrian peninsula (northern Adriatic) and is considered the main source of historical air pollution in the region. Between 1970 and 2000, sulfur-rich coal from the local Raša coal mine was primarily used. In this study, a screening of content and fate of TPP-derived sulfur in soil around the power plant was made two decades after the S-rich coal was banned from use. Soil samples were collected at varying distances from the TPP in the prevailing wind direction (NE), along with a control sample taken more than 10 km away. The samples were analyzed for total sulfur, sulfate, organic sulfur (humic and fulvic), and the stable isotope composition of total sulfur (δ³⁴S). Additionally, coal and coal ash were analyzed for total sulfur, sulfate and δ³⁴S. Soil sampling along the prevailing wind direction from the Plomin TPP revealed markedly elevated sulfur content, with levels at 100 m downwind reaching up to 4 wt.%, which is over 100 times higher than the 0.04 wt.% measured at the control site located upwind. Sulfur content decreases sharply with increasing distance from the TPP, reflecting the deposition gradient along the prevailing wind path. Speciation analysis showed that over 95% of the sulfur in the soil is now present in organic form, mainly bound to humic acids. The δ³⁴S_VCDT values of the bulk coal used in the TPP ranged from −10.0 to −5.0‰. In most soil samples, the bulk δ³⁴S values were positive (+7.0 to +20.0‰). The values of sulfate in soil range from +1.0 to +5.5‰, while those in organic sulfur range from −3.5 to +6.0‰. This indicates that atmospheric deposition of ³⁴S-depleted fly ash and sulfate from coal are the most important sulfur sources, while some of the sulfur in the soil is also of marine origin. Finally, we showed that natural attenuation was a significant and efficient process within the sustainable management of the site historically contaminated by anthropogenic atmospheric sulfur deposition.

Although one of the most abundant elements, magnesium is classified as a critical raw material by the EU. Demand for Mg and its compounds is increasing because of their widespread applications and emerging potential uses in various industries. Most primary Mg metal production occurs outside the EU and is dominated by thermal reduction and molten salt electrolysis, both energy-intensive processes. Furthermore, converting dolomite, CaMg(CO₃)₂, one of the main Mg sources, into usable feed material requires high temperatures. In our study, the production of Mg(OH)₂ was achieved through a two-step process involving selective leaching of Slovenian dolomite with H₂SO₄ and selective precipitation with hydroxide. The product contained 95% of the initial Mg and only 1% of Ca, resulting in a 97-fold enrichment in favour of Mg expressed as the Ca:Mg molar ratio. This process also supplied a CaSO₄ by-product, a potential source of Ca. Modifying the precipitation step with the use of chelating agents EDTA, EGTA, and DTPA did not significantly affect the Mg yield, but reduced Ca traces, thereby increasing the molar ratio to over 200. As an alternative pathway, calcination and silicothermic reduction of the dolomite demonstrated its suitability for the production of crystalline metallic Mg.

The authors would like to make the following corrections to the published paper