The Bogdanka coal mine, the only currently operating mine in the Lublin Coal Basin (LCB),
extracts coal from the Upper Carboniferous formations of the LCB. The average sulfur content in
the No. 385/2 seam is 0.98%, while in the case of the No. 391 seam it is slightly higher and amounts
to 1.15%. The iron sulfides (pyrite and marcasite) in bituminous coal seams form macroscopically
visible massive, vein, and dispersed forms. A microscopic examination has confirmed their complex
structure. Massive forms contain euhedral crystals and framboids. The sulfide aggregations are often
associated with a halo of dispersed veins and framboids. Pyrite and marcasite often fill the fusinite
cells. Framboids are highly variable when it comes to their size and the degree of compaction within
the carbonaceous matter. Their large aggregations form polyframboids. The cracks are often filled
with crystalline accumulations of iron sulfides (octaedric crystals). The Wavelenth Dispersive Spectrometry
(WDS) microanalysis allowed the chemical composition of sulfides in coal samples from the
examined depoists to be analyzed. It has been shown that they are dominated by iron sulfides FeS2 –
pyrite and marcasite. The examined sulfides contain small admixtures of Pb, Hg, Zn, Cu, Ag, Sb, Co,
Ni, As, and Cd. When it comes to the examined admixtures, the highest concentration of up to 0.24%,
is observed for As. In addition, small amounts of galena, siderite, and barite have also been found in
the examined coal samples. The amounts of the critical elements in the examined samples do not allow
for their economically justified exploitation. Higher concentrations of these elements can be found in
the ashes resulting from the combustion process.
Hydrogen sulfide (H2S) regulates many critical processes of plants. The effect of sodium hydrogen sulfide as H2S agent was investigated in basil plants under cadmium stress. A completely randomized design with three different concentrations (0, 50 and 100 μM) of CdCl2 and two levels of NaHS (0 and 100 μM) was used in this study. Cadmium exposure reduced growth parameters and relative water content. Cd also caused a significant increase in ion leakage and higher oxidative stress in terms of lipid peroxidation and H2O2 production. Although exogenous NaHS used in non-stressed control plants negatively affected growth and physiological parameters, it improved the root/shoot length ratio and fresh weight in basil plants under Cd 50 μM exposure. Moreover, NaHS alleviated deleterious effects of cadmium on ion leakage, relative water content and photosynthetic pigments of leaves. The activity of antioxidant enzymes like catalase, peroxidase and ascorbate peroxidase were also enhanced by NaHS in plants under moderate cadmium stress. Our results show that NaHS 50 μM ameliorates growth retardation induced by cadmium 50 μM stress in basil plants, probably through regulating physiological parameters such as photosynthetic pigments content, relative water content and the activity of antioxidant enzymes.
Measurements were made of sediment characteristics, benthic microbial activity and optimum temperature for sulfate reduction at Signy Island, South Orkney Islands, Antarctica . There was little evidence to support any seasonal variation in oxygen penetration of surface sediments. Oxygen penetrated to only 1.5 to 3 mm throughout the year, despite bioturbation from a dense amphipod population. The distribution of acid volatile sulfides increased with depth below 1 cm and above this, surface sediments were lighter in colour and contained fewer sulfides. The rates of sulfate reduction increased during winter under sea-ice cover, and remained high after ice break up. Seasonal water temperature was relatively constant between –1.8 and 0.5°C. Optimum temperature for anaerobic sediment respiration was investigated using different substrates and was found to be in the range 17–27°C, suggesting that sulfate reducing bacteria are psychrotolerant as they were inhibited by low temperatures.