Transformation of methane in peatlands environments

Wetlands and particularly peatlands are the main natural source of methane. Data indicate that 10–45% of methane emission comes from these sources. Methane emission from wetlands is the result of the balance between methanogenesis and methanotrophic processes and is actively affected by the wetland plant community composition. There are many factors affecting the balance of CH4: for instance, vegetation has a strong effect on CH4 emissions from wetland ecosystems by influencing methane production, consumption and transport in the soil. The effects of plants on methane fluxes may be mediated by: molecular diffusion, internal transport through plant aerenchyma tissues and ebullition. Methane is formed in the process of methanogenesis under anaerobic conditions. It may then be emitted into the atmosphere directly from the soil or by internal transport through the plant. Alternatively, it may undergo methane oxidation by methanotrophic bacteria, both free-living in the root zone and associated with the host plant in symbiosis. Sphagnum moss is of particular importance for this processes as it contains methanotrophic bacteria in its endophytic system. Methanotrophic bacteria live inside the dead hyaline cells or on the surface of Sphagnum leaves and are able to oxidise methane produced in the soil during methanogenesis, making peatlands a natural biofilter for methane, one of the main greenhouse gases

Classification of redox resistance of Polish arable soils and their spatial characteristics

Przemiany wielu składników gleb oraz wprowadzonych zanieczyszczeń mają związek z przemianami oksydoredukcyjnymi, które bezpośrednio są uwarunkowane obecnością akceptorów elektronów, tj.: tlenu cząsteczkowego, azotanów, tlenków manganu i żelaza oraz donorów elektronów, będących postaciami łatwo ulegającej rozkładowi materii organicznej gleby. Tempo przemian w środowisku glebowym zależy od żywotności mikroorganizmów, warunkowanych temperaturą i dostępnością substancji organicznej. Na podstawie wyznaczonych parametrów oksydoredukcyjnych wyodrębniono grupy gleb ornych Polski, charakteryzujących się zbliżoną odpornością oksydoredukcyjną. Rozkład wyznaczonych cech i ich przestrzenne przedstawienie w postaci mapy było celem prezentowanej pracy. Gleby zakwalifikowano do poszczególnych grup na podstawie analizy wartości t 300, określonych w temperaturze (4, 10, 15 i 20°C) dla trzech poziomów profilu glebowego (orny, podorny i podglebie). Analizę wyników przeprowadzono, dokonując podziału gleb na podzbiory zróżnicowane wartością odporności oksydoredukcyjnej. Grupy homogeniczne wyodrębnione na podstawie testu istotności stały się podstawą wyróżnienia grup jednostek glebowych. Uwzględniając zróżnicowanie wartości odporności oksydoredukcyjnej gleb wywołane wpływem temperatury oraz położeniem w profilu glebowym, wyodrębniono cztery grupy gleb, charakteryzujące się różną odpornością oksydoredukcyjną: nieznaczną ( 20 dni).Transformations of many soil components and pollutants are associated with redox conditions which are directly determined by the presence of electron acceptors (molecular oxygen, nitrates, manganese and iron oxides) and electron donors (easily decomposable soil organic matter). The rate of changes in soil habitat depends on viability of microorganisms determined by temperature and the availability of organic substances. Based on estimated redox parameters, groups of arable soils in Poland of similar resistance were distinguished. Distribution of the estimated features and their spatial presentation in a map were the aim of this paper. Soils were classified to particular groups upon the t 300 value estimated at 4, 10, 15 and 20 °C for three soil profiles (arable, sub-arable, subsoil). Analysis of results was performed by dividing soils into subsets of different redox resistance. Homogenous groups of soils were distinguished upon the significance test. Considering different soil redox resistance caused by temperature and position in the soil profile, four groups of slight ( 20 days) redox resistance were distinguished

Wypłukiwanie metali ciężkich (Fe, Zn i Ni) ze skał przywęglowych

The majority of heat and energy delivered to Polish houses derive from coal combustion. The exploitation of underground resources is connected with excavation of huge quantities of metal-rich waste rocks. These metals may be released to the environment and contribute to the pollution of water and soil systems which is dangerous for biota and human health. The mobility and bioavailability of metals depend on their chemical form. In present work, we determined geochemical speciation of Fe, Ni and Zn in samples of waste rocks from five coal mines from both USCB and LCB. The most abundant metal in easily-extractable phases (water-soluble, exchangeable, acid-soluble) was Zn (MFZn = 24.4÷53.4) followed by Ni (MFNi = 5.1÷19.2) and Fe (MFFe = 0.2÷3.6). The mobility of Fe was similar in rocks originating from both coal basins (K-W, p = 0.2253), Ni was higher in LCB whereas Zn in USCB rocks (K-W, p < 0.05). It was also found that during first years of storage and exposure to natural weathering, only a small portion of metals was released to the environment as the total concentrations and fractionation of Fe, Ni and Zn were similar in fresh and weathered coal waste rocks from Wesola and Murcki coal mines, up to 3 and 15 years of weathering, respectively.Większość ciepła i energii dostarczanej do polskich domostw pochodzi ze spalania węgla kamiennego. Podziemna eksploatacja tego surowca związana jest z wydobyciem na powierzchnię dużych ilości bogatych w metale skał przywęglowych. Metale te mogą zostać uwolnione do środowiska, przyczyniając się tym samym do zanieczyszczenia gleby i wody, które jest niebezpieczne dla organizmów żywych i zdrowia ludzi. Mobilność i biodostępność metali zależy od ich chemicznej postaci. W bieżącej pracy przedstawiono wyniki geochemicznej specjacji Fe, Ni oraz Zn w próbkach odpadowych skał przywęglowych z pięciu kopalni GZW i LZW. Wykazano, że w łatwo wypłukiwanej formie (wodno-rozpuszczalnej, wymiennej, kwaso-rozpuszczalnej) największe stężenia osiągał Zn (MFZn = 24,4÷53,4), następnie Ni (MFNi = 5,1÷19,2) i Fe (MFFe = 0,2÷3,6). Mobilność Fe była porównywalna w skałach pochodzących z obu Zagłębi (K-W, p = 0,2253), Ni większa z LCB, natomiast Zn z USCB (K-W, p < 0,05). Przeprowadzone badania wskazują, że przez pierwsze lata składowania jedynie niewielka część metali zostaje uwolniona do środowiska, ponieważ zarówno stężenia całkowite, jak i specjacja Fe, Ni i Zn były podobne w świeżych i zwietrzałych skałach kopalni Wesoła i Murcki (odpowiednio do 3 i 15 lat wietrzenia)

Influence of plant composition on methane emision from Moszne peatland

Methane is the second most important man-made greenhouse gas after carbon dioxide. For more than the last 20 years the increase of the rate of CH4 emission has been varying dramatically each year. This trend is common worldwide, though in different parts of the world unevenly intense, conditioned by the amount of emissions from natural and anthropogenic sources. Peatland ecosystems are one of the natural methane emitters, responsible for about 24% of the total CH4 emissions. Methane emission from wetlands is the balance between the processes of methanogenesis and methanotrophy with an active role of wetlands plants composition. Participation of vegetation in the reduction the emissions by 30-35% was confirmed. Association of methanotrophic bacteria with plants has been already recognized by Raghoebarsing and colleagues, who showed that methanotrophic bacteria, as endosymbionts and epibionts, live both inside and outside the cells of Sphagnum sp. The main aim of this study was to estimate methane emissions from Moszne peatland, dominated by: Sphagnum sp., Eriophorum vaginatum, Carex nigra and Vaccinium uliginosum

The mechanical properties at room and low temperature of P110 steel characterised by means of small punch test

In this paper small punch test (SPT) which is one of miniaturized samples technique, was employed to characterize the mechanical properties of carbon steel P110. The tests were carried out in the range of -175°C to RT. Results obtained for SPT were compared to those calculated for tensile and Charpy impact test. Based on tensile and SPT parameters numerical model was prepared. 8 mm in diameter and 0.8 mm in height (t) discs with and without notch were employed in this research. The specimens had different depth notch (a) in the range of 0.1 to 0.4 mm. It was estimated that α factor for comparison of Tsp and DBTT for carbon steel P110 is 0.55 and the linear relation is DBTT = 0.55TSPT. The numerical model fit with force – deflection curve of SPT. If the factor of notch depth and samples thickness is higher than 0.3 the fracture mode is transformed from ductile to brittle at -150°C

A survey of greenhouse gases production in central European lignites

Due to changes in the energy market, it is projected that lignite excavation will be reduced in the near future. Cessation of exploitation is associated with restitution of natural water conditions and flooding of the resources left in the mines. Flooded lignite mines are a potential source of greenhouse gases (GHG) (CH4, CO2 and N2O), which should be monitored due to growing environmental concerns. Here, we aim to recognize GHG release from the lignites collected from the main deposits of Poland, Slovenia and Serbia. GHG production was studied along with a range of physical and chemical parameters that are crucial for microbial growth and activity. The microcosm experiments showed that the main gas emitted from the lignites was carbon dioxide. Daily CO2 production was highly variable. The highest values were recorded for detroxylitic lignite collected from the Konin deposit (402.05 nmol CO2 g-1 day-1) while the lowest were for the Kolubara xylitic lignite (19.64 nmol CO2 g-1 day-1). Methane production was much lower and ranged from nearly zero to 66.75 nmol g dry mass-1 d-1. Nitrous oxide production was not detected. It was found that CO2 production, being a general measure of microbial activity, was positively affected by NO3- concentration and redox potential. With respect to methane formation, the lower atmospheric oxygen exposure of the sample from the Velenje underground mine compared to the samples from the opencast mines has been identified as a possible cause of the high methane production. The overall global warming potential (GWP) of the gases released by xylitic lignite was lowest among the samples. Preferential extraction of the detritic lignites is suggested as a means to reduce GHG emissions from the abandoned lignite mines

Microbial involvement in carbon transformation via ch<inf>4</inf> and co<inf>2</inf> in saline sedimentary pool

Methane and carbon dioxide are one of the most important greenhouse gases and significant components of the carbon cycle. Biogeochemical methane transformation may occur even in the extreme conditions of deep subsurface ecosystems. This study presents methane-related biological processes in saline sediments of the Miocene Wieliczka Formation, Poland. Rock samples (W2, W3, and W4) differed in lithology (clayey salt with veins of fibrous salt and lenses of gypsum and anhydrite; siltstone and sandstone; siltstone with veins of fibrous salt and lenses of anhydrite) and the accompanying salt type (spiza salts or green salt). Microbial communities present in the Miocene strata were studied using activity measurements and high throughput sequencing. Biological activity (i.e., carbon dioxide and methane production or methane oxidation) occurred in all of the studied clayey salt and siltstone samples but mainly under water-saturated conditions. Microcosm studies performed at elevated moisture created more convenient conditions for the activity of both methanogenic and methanotrophic microorganisms than the intact sediments. This points to the fact that water activity is an important factor regulating microbial activity in saline subsurface sediments. Generally, respiration was higher in anaerobic conditions and ranged from 36 ± 2 (W2200%t.w.c ) to 48 ± 4 (W3200%t.w.c ) nmol CO2 gdw−1 day−1 . Methanogenic activity was the highest in siltstone and sandstone (W3, 0.025 ± 0.018 nmol CH4 gdw−1 day−1 ), while aerobic methanotrophic activity was the highest in siltstone with salt and anhydrite (W4, 220 ± 66 nmol CH4 gdw−1 day−1 ). The relative abundance of CH4-utilizing microorganisms (Methylomicrobium, Methylomonas, Methylocystis) constituted 0.7–3.6% of all taxa. Methanogens were represented by Methanobacterium (0.01–0.5%). The methane-related microbes were accompanied by a significant number of unclassified microorganisms (3–64%) and those of the Bacillus genus (4.5–91%). The stable isotope composition of the CO2 and CH4 trapped in the sediments suggests that methane oxidation could have influenced δ13CCH4, especially in W3 and W4