The estimated diffusion fluxes of methane (CH₄) and carbon dioxide (CO₂) at the sediment–water interface in the Rzeszów Reservoir in southeastern Poland are presented. The relevant studies were conducted during 2009, 2010, and 2011. Calculated fluxes ranged from 0.01 to 2.19 mmol m⁻² day⁻¹and from 0.36 to 45.33 mmol m⁻² day⁻¹for methane and carbon dioxide, respectively. While the values for calculated diffusion fluxes of methane are comparable with those reported for other eutrophic reservoirs, much higher values were obtained here for carbon dioxide. The resulting values of δ¹³C-CH₄and the fractionation coefficients between methane and carbon dioxide (αCH₄-CO₂) suggest that methane in the sediment of the Rzeszów Reservoir is produced by acetate fermentation, while the hydrogenotrophic methanogenic process is of successively greater importance with increasing depth. In the top layer of the sediment, 24–72 % of CO₂came from methanogenesis, while the contribution made by the degradation of organic matter by methanogenesis to CO₂was greater in the deeper layer.

Rhizoctonia zeae SOL3 fungus was isolated from contaminated soil based on its ability to decolorize remazol brilliant blue R in solid medium. This fungus has been used to degrade pyrene a four-ring polycyclic aromatic hydrocarbon. R. zeae SOL3 could biodegrade pyrene as a sole source of carbon and energy. Different parameters were investigated to study their effect on the biodegradation rate. The highest biodegradation rate reached at 28 °C, non-agitated culture, 20 g/L glucose, 24 g/L NaCl, and 20 mg/L pyrene. The metabolites of pyrene were detected by thin layer chromatography (TLC) and confirmed by gas chromatography–mass spectrometry (GC-MS), which were identified as benzoic acid, 4-hydroxybenzoic acid and botanic acid.

We analysed nutrients and basic ions (Na, Cl, K, Mg, Si, Ca, and SO₄) for a period of 1 year, including every precipitation event, and sampled stream water every 2 weeks from a forest catchment in Shimane Prefecture, Japan. Backward-trajectory analysis revealed that some air masses originated within Japan, but did not affect the precipitation chemistry. Air masses originating from northern China were positively correlated with nutrients and all basic ions. Concentrations of ammonium and dissolved organic nitrogen were much lower in stream water than in precipitation, while those of nitrate and particulate nitrogen were similar in stream water and precipitation. Unlike nitrogen, the dissolved phosphorus concentration was much higher in stream water than in precipitation. Both phosphate and dissolved organic phosphorus (DOP) levels were higher in stream water than in precipitation. Particulate phosphorus (PP) concentrations were very similar in precipitation and stream water. PP showed stronger correlations than potassium with suspended solids (SS) and flow rate, while phosphate and DOP were more strongly correlated with potassium than with SS or flow rate. Stream silica concentrations were not correlated with phosphate but did exhibit a significant negative correlation with DOP. Neither phosphate nor DOP was correlated with calcium. These results suggest that phosphorus is not leaching with silica or calcium as a paired cation, but rather with potassium in this area. Lower nitrogen concentrations in stream water than in precipitation can be attributed to an enhanced uptake of nitrogen by forest soils owing to the increased atmospheric deposition of phosphorus.

The majority of the existing water bodies around the world are increasingly polluted with oily wastewater. The aim of this study was to investigate the role of single protozoan isolates (Aspidisca, Trachelophyllum and Peranema) and of a consortium of these three protozoan isolates in the biodegradation of fats and oils present in polluted domestic wastewater. The biomass of protozoan isolates, chemical oxygen demand (COD), dissolved oxygen (DO) and concentrations of fats and oils were determined in triplicate before and after the inoculation of isolates in oily wastewaters, using standard methods. Results revealed optimum growth of protozoan cell densities under favourable conditions of 30 °C, pH 6 and 8 (from 1.00 to 4.00, 3.96, 3.80 and 4.20 × 10²cells/ml for Aspidisca, Trachelophyllum, Peranema and a consortium of the three isolates, respectively). The average percentage uptake of DO by Aspidisca, Trachelophyllum, Peranema and their consortium was 95, 96, 96 and 100 %, respectively, for both 30 and 25 °C and at pH levels of (4, 6, 8 and 10), respectively. The results revealed that the COD removal rates of the isolates at various pH levels were ≥20 and ≤90 %, respectively, for 30 and 25 °C. At a temperature of 30 °C, the biodegradation capabilities of the isolates ranged from 3.0 to 8.0, 3.0 to 6.0, 7.0 to 11.0 and 8.0 to 22.0 %, while at 25 °C, the biodegradation rates were 3.0 to 6.0, 4.0 to 7.0, 3.0 to 8.0 and 4.0 to 15.0 % for Aspidisca, Trachelophyllum, Peranema and the consortium of these three isolates, respectively.

Chemical contamination of water resources on the planet generates a range of environmental disturbances which impair ecosystems. Humans ingest such chemicals often present in water. Conventional treatments fail to remove these contaminants from water, requiring complementary methods such as activated carbon filters, reverse osmosis, or distillation, which are expensive and seldom used in the public water supply. In recent years, there has been a search for alternative eco-friendly, low-cost methods which can effectively remove these contaminants. This study was conducted to test the effectiveness of biotite (black mica), an igneous mineral of the mica group, in removing pesticides from water. A trial was designed to assess the rate of pesticide removal using a methodology based on axes of variation of pH, temperature, concentration, and time. The pesticides tested were atrazine, fluazifop-p-butyl, lambda-cyhalothrin, chlorpyrifos, and lactofen. The results showed higher removal rates in acidic conditions (pH 3) and temperatures between 20 and 30 °C, requiring about 6 h to reach maximum adsorption. More than 80 % of all the pesticides were adsorbed. The best result was obtained for fluazifop (94.2 %) in 6 h, under pH 3, and temperature of 25 °C. The study revealed that biotite has a high absorption capacity of complex and varied compounds. These findings signal the need for further studies and tests. Due to the high cost of pesticide analysis, which can only be made using a chromatograph mass spectrometer, financial resources will be required.

The development of nanotechnology has increased the amount of nanoparticles in the environment inducing pollution. In view of increasing amounts, their toxicity assessment becomes important. Aluminum oxide nanoparticles (Al₂O₃ NPs) have a wide range of applications in industry. The present study aims to reveal the time-dependent (24, 48, 72, 96 h) and dose-dependent (0, 5, 25, 50 mg/ml) effects of 13-nm-sized Al₂O₃ NPs on an agronomic plant wheat (Triticum aestivum L.) roots correlating with the appearance of various cellular stress responses. Al₂O₃ NPs reduced the root elongation by 40.2 % in 5 mg/ml, 50.6 % in 25 mg/ml, and 54.5 % in 50 mg/ml after 96 h. Histochemical analysis revealed lignin accumulation, callose deposition, and cellular damage in root cortex cells correlating the root elongation inhibition. Although the nanoparticle application decreased the total protein content with respect to control after 96 h, the peroxidase activity increased significantly which is considered to be one of the oxidative stress factors. Moreover, agarose gel results revealed that Al₂O₃ NPs induced DNA fragmentation being one of the important markers of programmed cell death. In conclusion, direct exposure to Al₂O₃ NPs leads to phytotoxicity significantly in wheat roots culminating in morphological, cellular, and molecular alterations.

Tropical coastal areas are sensitive ecosystems to climate change, mainly due to sea level rise and increasing water temperatures. Furthermore, they may be subject to numerous stresses, including heat releases from energy production. The Urias coastal lagoon (SE Gulf of California), a subtropical tidal estuary, receives cooling water releases from a thermoelectric power plant, urban and industrial wastes, and shrimp farm discharges. In order to evaluate the plant thermal impact, we measured synchronous temperature time series close to and far from the plant. Furthermore, in order to discriminate the thermal pollution impact from natural variability, we used a high-resolution hydrodynamic model forced by, amongst others, cooling water release as a continuous flow (7.78 m³ s⁻¹) at 6 °C overheating temperature. Model results and field data indicated that the main thermal impact was temporally restricted to the warmest months, spatially restricted to the surface layers (above 0.6 m) and distributed along the shoreline within ∼100 m of the release point. The methodology and results of this study can be extrapolated to tropical coastal lagoons that receive heat discharges.

One of the most important particles of biological origin present in the air is pollen grains of plants. Having basic biological function in the process of pollination, pollen grains of some plant species can cause allergic reactions among 20–30 % of the human population and thus affect their health and overall quality of life. Bearing in mind the potential influence air pollutants and meteorological parameters may have on release of pollen and granules of allergen from pollen, concentrations of air pollutants and 26 different anemophilous aeropollen types as well as meteorological parameters were established in a 5-year period (2009–2013) in Subotica, Northern Serbia. Spearman’s rank correlation was made for statistical analysis of relationships between concentration of some air pollutants (sulphur dioxide, nitrogen dioxide, soot, particulate matter (PM)₁₀ and PM₂.₅), meteorological factors (temperature of air, humidity, wind speed, cloud index) and airborne pollen. In most of the examined years, significant positive correlations were determined between temperature and total pollen concentration, while significant negative correlations were established between humidity as well as cloud index and total pollen concentration, clearly proving the influence these meteorological parameters have on pollination of all examined species.

Fe₂O₃/γ-Al₂O₃catalysts were prepared using the wet impregnation method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen adsorption–desorption. The continuous catalytic wet hydrogen peroxide oxidation of an aqueous phenol solution over Fe₂O₃/γ-Al₂O₃was studied in a fixed-bed reactor. The effects of several factors, such as the weight hourly space velocity (WHSV), particle size, reaction temperature, H₂O₂concentration, and initial pH, were studied to optimize the operation conditions for phenol mineralization. For a 1 g L⁻¹phenolic aqueous solution, the phenol was nearly completely removed and chemical oxygen demand (COD) removal was approximately 92 % at steady-state conditions with a WHSV of 2.4 × 10⁻² gPₕOH h⁻¹ gcₐₜ⁻¹at 80 °C with 5.1 g L⁻¹H₂O₂. The long-term stability of the Fe₂O₃/γ-Al₂O₃catalyst was also investigated for the continuous treatment of phenolic water. The removal of phenol and COD exhibited a slowly decreasing trend, which was primarily due to the complexation of active sites with acid organic compounds and the adsorption of intermediate products. The deposition of organic carbon and Fe leached from the catalyst had a small role in the partial deactivation of the catalyst. The Fe leached from the catalyst partially contributed to the phenol removal during a short run. However, this contribution could be neglected after 36 h because the Fe leached from the catalyst decreased to approximately 5 mg L⁻¹.

Methane production by methanogenic microbes under anaerobic condition is affected by the types of fertilizers, which determine carbon availability, used in rice fields. In addition, irrigation management controls oxygen availability in soil. Thus, irrigation management and types of fertilizers are major driving forces for methane emission in rice fields. While these factors affect paddy microbial communities over the course of cultivation, little is known about the effects of fertilizers and irrigation conditions on initial paddy microbial communities. In this study, we investigated the initial impacts of fertilizers and irrigation systems on paddy microbial communities and methane emission. At early stages of rice cultivation (2 weeks after transplanting 15-day-old rice seedlings), a high amount of methane was emitted from rice fertilized with swine manure. In addition, pre-transplantation flooding increased methane emission by 30 %. Although these conditions did not affect the overall paddy soil microbial communities, 126 operational taxonomic units (OTUs) were found to be significantly more abundant in paddy soils fertilized with swine manure. These OTUs included archaeal methanogenic species and bacterial substrate providers for biomethane production. Shared-OTU analysis with swine fecal microbial communities indicated swine manure as the origin of key methane-producing microbes. In conclusion, the applications of swine manure and permanent flooding irrigation introduce active methane producers and enhance methane emission, respectively, and should therefore be avoided.