Sulfur Contamination and Environmental Effects: A Case Study of Current SO2 Industrial Emission by Biomonitoring and Regional Post-mining hot-spots

The presence of sulfur in the environment is an important macroelement for plant growth but becomes harmful in excessive amounts. The previous century saw rising levels of high SO2 concentrations (stemming from fossil fuel combustion) and wet deposition from acid rain, causing the intensification of forest die-back. Air pollution can be controlled or measured by biomonitoring. Despite recent reductions in SO2 emissions, urban and industrial areas are still at risk from high sulfur contamination. Open-cast lignite and sulfur borehole mining play a pivotal role in the regional scale of ecosystem contamination and acid mine drainage. Consequently, these aspects are unique for assessing the impact of extreme S contamination on soil properties changes, the vegetation effect, and biogeochemical cycles. We presented i) current SO2 pollution based on S concentration in pine needles, and ii) a comprehensive study of soil properties, as well as plant reactions to excessive sulfur concentration in the restored forest ecosystem of a former sulfur mine.

Comprehensive Study of Reclaimed Soil, Plant, and Water Chemistry Relationships in Highly S-Contaminated Post Sulfur Mine Site Jeziórko (Southern Poland)

The aim of the work was a comprehensive study of the soils (pH, EC, SOC, NT, ST), surface waters (pH, EC, Ca2+ Mg2+, Na+, NO3−, SO42−, Cl−, HCO3−), and reactions of trees and herbaceous plants in the restored forest ecosystem of a former sulfur mine. Common birch and Scots pine growth reaction, vitality (according to IUFRO standards- International Union of Forest Research Organizations), nutrient supply (Na, K, P, Ca, Mg, K), and Calamagrostis epigejos (L.) Roth chemical composition (Na, K, P, Ca, Mg, K) were assayed. The chemistry dynamics (pH, EC, DOC, NT, Ca, Mg, and S at the beginning and end of the experiment) of soil leaching and the sulfur load leached from the sulfur-contaminated soil substrates were evaluated. The remediation effects of birch and pine litter were assayed in an experiment under controlled conditions. It was found that reclamation was effective in the majority of the post-mining site; however, hotspots with sulfur contamination reaching even 45,000 mg kg−1, pH < 2.0 and electrical conductivity (EC) of 6500 µS cm−1 were reported. Surface waters typically displayed elevated concentrations of sulfate ions (average 935.13 mg L−1), calcium ions (up to 434 mg L−1), and high EC (average 1797 µS cm−1), which was related both to sulfur contamination and the sludge lime that was used in neutralization. Calamagrostis epigejos was found to be a species that adapted well to the conditions of elevated soil salinity and sulfur concentration. It was observed that the application of organic matter had a significant beneficial impact on the chemistry of soil solutions, but did not show a remediation effect by increased sulfur leaching in a short-term study.

Comprehensive Study of Soil-Plant and Surface Water Chemistry Relationships in Highly S Contaminated Environment on Reforested Former Sulfur Borehole Mine Sites

Sulfur contamination of topsoil, spatial distribution of contamination and surface water chemistry were investigated on an area of over 200 ha of a new forest ecosystem. Common birch and Scots pine growth reaction, vitality and nutrients supply, as well as wood small-reed (Calamagrostis epigejos (L.) Roth) chemical composition were assayed. The chemistry dynamics of soil leaching and the sulfur load leached from the sulfur contaminated soil-substrates were analyzed. The remediation effect of the birch and pine litter was assayed in an experiment under controlled conditions. It was found that reclamation was effective in a majority of the post-mining site, however hot-spots with sulfur contamination reaching even 45,000 mg kg-1, pH &lt;2.0, and EC 6,500 &micro;S cm-1 were reported. Surface waters typically displayed elevated concentrations of sulfate ions (average 935.13 mg L-1), calcium ions (up to 434 mg L-1) and high EC (average 1.795 &micro;S cm-1), which was connected both with sulfur contamination and sludge lime used in neutralization. Wood small-reed was found to be species adapting well to the conditions of elevated soil salinity and sulfur concentration. We noted that an addition of organic matter had a significant impact on the chemistry of soil solutions but did not indicate in short term experiment a remediation effect by increased sulfur leaching.