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Copper oxide catalysts (CuOx) supported on gamma alumina (γ-Al2O3) were employed for the catalytic reduction of sulfur dioxide (SO2) to elemental sulfur by methane (CH4). The catalysts were synthesized using a straightforward sol–gel method. Initially, alumina was obtained through a precipitation technique. X-ray diffraction (XRD) analysis was conducted to confirm the formation of γ-Al2O3. This study aimed to investigate the impact of reaction temperature (T = 600–800 °C) and Cu loading (0–15 wt%) on SO2 conversion and sulfur selectivity. Under the reaction conditions of 800 °C, 1 bar, SO2 = 5000 ppm, CH4 = 2500 ppm, gas hourly space velocity (GHSV) = 12,000 1/h, and 10 wt% Cu, the SO2 conversion and sulfur selectivity were determined to be 95% and 94.5%, respectively. The influence of the molar feed ratio of SO2/CH4 = R = 0.5–3 on the 10 wt% Cu catalyst was also investigated in the temperature range of 600–800 °C. The findings revealed that when R < 2, the conversion rate increased due to higher SO2 reduction with an excess of CH4, but sulfur selectivity slightly decreased as a result of the formation of unwanted byproducts such as H2S and COS. Conversely, when R > 2, SO2 conversion significantly declined, while sulfur selectivity was enhanced due to increased consumption of CH4. [ABSTRACT FROM AUTHOR]

In the present work, with the aid of the density functional theory (DFT) method, we have investigated the possibility of applying the B3S monolayer (B3SML) for sensing and adsorption of some air pollutants containing SO2, CS2, CO2, CH2O, H2O, C2H2, and CF3H from the gaseous environment. The results showed that after the adsorption of SO2, H2O, and C2H2 by B3SML, big changes took place which led to a decrease of the λmax of each complex down to 1598.5 nm, 1418.0 nm, and 1580.0 nm, respectively. Therefore, the frequencies of the mentioned adsorption complexes rise and strong blueshifts occur. Moreover, the outcomes of the band gap estimations reveal that the B3SML could selectively detect the existence of C2H2 with a clearer and stronger electronic signal compared to all other gases. In addition, this nanosheet is able to sense CS2, CH2O, SO2, and H2O with good signals. Hence, it could not recognize the difference between CH2O and SO2 gases. Also, the results of the thermodynamic calculations indicate that B3SML would selectively adsorb and destruct SO2, C2H2, and H2O gases. Moreover, this sorbent could adsorb CH2O and CS2 species, but it would approximately not adsorb CO2 and CF3H. [ABSTRACT FROM AUTHOR]

Southeastern Europe (SEE), which includes Serbia, along with Germany and Poland, is one of the largest producers of solid fuels in Europe. Despite growing environmental concerns, coal, especially lignite, persists and remains the dominant fuel for electricity generation in this region. Concurrently, these power plants emerge as the predominant emitters of pollutants in all the observed states. To conduct a comprehensive analysis, data on major emitters within the EU were gathered, allowing for a detailed comparison with SEE countries. A specific focus was placed on the thermal power plant Kostolac in Serbia, where the calculation of SO2 emissions for two thermoblocks was undertaken. Comparisons were drawn with emitters in EU countries, with a particular emphasis on SEE nations. The analysis involved data from wells that have undergone excavation over specific periods, facilitating an exploration of the correlation between calculated values, those from exploited wells, and projections of future SO2 emissions from new wells in areas earmarked for surface mining exploitation. [ABSTRACT FROM AUTHOR]

Complex mixtures of air pollutants, including ozone (O3), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), black carbon (BC), and fine particulate matter (PM2.5), present significant health risks. To understand the factors influencing air pollution levels and their temporal variations, comprehensive high-resolution long-term air pollution data are essential. This study analyzed the characteristics, lagged meteorological effects, and temporal patterns of six air pollutant concentrations over a one-year period at an urban residential site in Kenitra, Morocco. The results reveal pronounced seasonal and diurnal variations in pollutant levels, shaped by meteorological factors, emission sources, and local geographic conditions. PM2.5, SO2, and CO concentrations peaked during winter, while NO2 and CO exhibited consistent diurnal peaks during morning and evening rush hours across all seasons, driven by traffic emissions and nocturnal pollutant accumulation. In contrast, O3 concentrations were highest during summer afternoons due to photochemical reactions fueled by strong UV radiation, while winter levels were the lowest due to reduced sunlight. Lagged meteorological effects further highlighted the complexity of air pollutant dynamics. Meteorological factors, including temperature, wind speed, humidity, and pressure, significantly influenced pollutant levels, with both immediate and lagged effects observed. Lag analyses revealed that PM2.5 and BC levels responded to wind speed, temperature, and humidity over time, highlighting the temporal dynamics of dispersion and accumulation. CO is sensitive to temperature and pressure changes, with delayed impacts, while O3 formation was primarily influenced by temperature and wind speed, reflecting complex photochemical processes. SO2 concentrations were shaped by both immediate and lagged meteorological effects, with wind direction playing a key role in pollutant transport. These findings emphasize the importance of considering both immediate and lagged meteorological effects, as well as seasonal and diurnal variations, in developing air quality management strategies. [ABSTRACT FROM AUTHOR]

Investigating effective sorbent materials in the CO2 sorption process is crucial. Lithium-based sorbents combine high carbon capture efficiency with excellent mechanical stability. Lithium orthosilicate (Li4SiO4) was prepared for the CO2 capture test in this study with a variety of variables, including the sorbent calcination temperature, space velocity, operation temperature, and water vapor and SO2 concentrations. Several analyses were used in the characterization of the spent and fresh sorbents. Additionally, the CO2 sorption reaction kinetics were investigated using deactivation models. The sorbent with the best utilization value was obtained via calcining Li4SiO4 at 700 °C for five hours. Li4SiO4 demonstrated exceptional stability in the 600–800 °C temperature and 1200–6000 mL/h/g space velocity ranges. The performance of the sorbent was not significantly affected by the water vapor content up to 10%. Nevertheless, further increasing the water vapor stream drastically declined its performance due to water masking on the sorbent's surface. Similar sorption trends were demonstrated by Li4SiO4 in all SO2 content setups. The Type I deactivation model was well fitted to the experimental data. [ABSTRACT FROM AUTHOR]

Air pollutants, specifically, Sulphur Dioxide (SO2) and Nitrogen Dioxide (NO2) cause numerous biochemical changes in plants; by studying the biochemical parameters, plant resistance against these pollutants can be evaluated. The effect of air pollutants on biochemical parameters such as ascorbic acid (AA), total chlorophyll (TC), pH and the relative water content (RWC) of leaves has been investigated in the present study. The objective of the present study was to observe the relationship between biochemical parameters of plants and ambient air pollutants (SO2 and NO2). The morphological and biochemical changes of the sampled leaves of different plants were studied. Simultaneously, ambient air quality data was collected from the central pollution control board (CPCB) online portal. Among the sampled plants, Ficus religiosa and Morus alba plant species can be recommended as tolerant for the sampling sites: Jalandhar, Amritsar, and Ludhiana. Ficus benghalensis and Ficus religiosa can be recommended as tolerant for Chandigarh sector 25 and 53 respectively. As a result, it has been observed that SO2 has a negative effect on the relative water content and ascorbic acid content of most plant species, while NO2 can have ambiguous effect on plants (toxic and beneficial), and no strong association has been found with biochemical parameters. The current study provides pollutant-specific information and insights into the variations caused by air pollutants. The present study will contribute in suggesting the tolerant plant species that could provide new approaches for developing urban landscapes. [ABSTRACT FROM AUTHOR]