Biomass integrated gasification combined cycle (IGCC) is attracting increased interest because it can achieve high system energy efficiency (>50%), which is predicted to increase with the increase in the solar share in biomass IGCC. This study evaluated the potential of crop residues numerically for the co-production of power and bio-fertilizer using ASPEN Plus® simulation software. The results showed that the gas yield increases with increasing temperature and decreasing pressure while the yield of bio-fertilizer is dependent on the biomass composition. The biomass with a low ash content produces high bio-fertilizer at the designated gasification temperature. The IGCC configuration conserves more energy than a directly-fired biomass power plant. In addition, the solar-assisted IGCC attains a higher net electricity output per unit of crop residue feed and achieves net thermal efficiencies of around 53%. The use of such hybrid systems offer the potential to produce 0.55 MW of electricity per unit of solar-thermal energy at a relatively low cost. The ASPEN Plus model predicted that the solar biomass-based IGCC set up is more efficient in increasing the power generation capacity than any other conversion system. The results showed that a solar to electricity efficiency of approximately 55% is achievable with potential improvements. This work will contribute for the sustainable bioenergy production as the relationship between energy production and biomass supplies very important to ensure the food security and environmental sustainability.

Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs), including petroleum biomarkers, were studied in four sediment cores collected around Deception and Penguin Islands, Antarctica. Total PAHs in Deception Island (DCP) samples ranged from 2.0 to 26.8 ng g⁻¹, and in Penguin Island (PGI) varied between 13.2 and 60.3 ng g⁻¹. Multiple sources of PAHs were verified in DCP, with petrogenic-derived compounds being predominant over the last 10 years. In PGI, PAHs related to natural contributions from the erosion of coal deposits were reported. Total AHs in DCP ranged from 4.5 to 19 μg g⁻¹ and in PGI varied between 5.3 and 21.9 μg g⁻¹. In DCP, the n-alkanes distribution pattern showed the presence of petroleum residues in the top sections and both terpanes and hopanes were detected, related to the use of fossil fuels for power generation and in different types of vessels. In PGI, the main source of n-alkanes was marine inputs and only terpanes were detected. The slight increase in hydrocarbon levels observed from 1980 onward in DCP was assumed to be due to the development of tourism in the region and to the scientific station activities. In PGI, anthropogenic-related hydrocarbons were detected in the recent sections and were linked to the development of tourism near the island, scientific activities and the increase in vessel traffic. In general, the concentrations of hydrocarbons found around both islands were comparable to those found in uncontaminated Antarctic regions.

In early nineteen century, a gas field was operational in southern part of Sindh, Pakistan for power production. The plant was completely un-operational for last three decades, whereas all wastage and raw materials are still dumped there, which might be the source to contaminate the ground water. The most of the workers population still living in different villages nearby the gas field. In present study, evaluated the undesirable effects of the toxic metals (lead and cadmium) via consuming groundwater for drinking and other domestic purpose especially in children of ≤5.0 years. For comparative purpose groundwater of nonindustrial area (nonexposed) was also analysed and their impact on age matched children was carried out. Biological samples (scalp hair and blood) were collected from children of exposed and nonexposed areas. The Cd and Pb in scalp hair and blood samples were carried out by graphite furnace atomic absorption spectrometry. Whereas, Cd and Pb in groundwater obtained from both areas were determined prior to applied preconcentration method as reported in our previous works. The Cd and Pb contents in the groundwater of villages of exposed area were found in the range of 5.18–10.9 and 19.9–69.5 μg/L, respectively. Whereas, the groundwater of nonexposed area contains Cd and Pb in the range of 1.79–3.78 and 5.07–24.3 μg/L, respectively. It was observed that the concentrations of Cd and Pb in scalp hair and blood samples of children belongs to exposed area have ≥2.0 fold higher than the resulted data attained for age matched control children, indicating as the exposure biomarkers of toxic metals. The children belong to exposed area have poor health, anemic and low body mass index (<13 kg/m2). A significant positive correlations among Cd and Pb concentrations in biological samples of exposed subjects and groundwater was observed (p < 0.01).

Based on the application of sediment microbial fuel cell (SMFC) in the bioremediation of sediment, this study used the sediment microbial fuel cell technology as the leading reactor. Modification of anode carbon felts (CF) by synthesis of PANI/MnO₂ composited to improve the electrical performance of the sediment microbial fuel cell. This study investigated the degradation effects, degradation pathways of the specific contaminant enrofloxacin and microbial community structure in sediment microbial fuel cell systems. The results showed that the sediment microbial fuel cell system with modified anode carbon felt (PANI-MnO₂/CF) prepared by in-situ chemical polymerization had the best power production performance. The maximum output voltage was 602 mV and the maximum power density was 165.09 mW m⁻². The low concentrations of enrofloxacin (12.81 ng g⁻¹) were effectively degraded by the sediment microbial fuel cell system with a removal rate of 59.52%.

Lead (Pb) is a toxic element which is released as a result of anthropogenic activities, and Pb stable isotope ratios provide a means to distinguish sources and transport pathways in receiving environments. In this study, isotopes of bioaccumulated Pb (²⁰⁴Pb, ²⁰⁶Pb, ²⁰⁷Pb, ²⁰⁸Pb) were examined for diverse terrestrial and aquatic biota from three areas in western Canada: (a) otter, marten, gulls, terns, and wood frogs in the Alberta Oil Sands Region (AOSR), (b) fish, plankton, and gulls of Great Slave Lake (Yellowknife, Northwest Territories), and (c) wolverine from the Yukon. Aquatic and terrestrial biota from different habitats and a broad geographic area showed a remarkable similarity in their Pb isotope composition (grand mean ± 1 standard deviation: ²⁰⁶Pb/²⁰⁷Pb = 1.189 ± 0.007, ²⁰⁸Pb/²⁰⁷Pb = 2.435 ± 0.009, n = 116). Comparisons with Pb isotope ratios of local sources and environmental receptors showed that values in biota were most similar to those of atmospheric Pb, either measured in local aerosols influenced by industrial activities in the AOSR or in lichens (an aerosol proxy) near Yellowknife and in the Yukon. Biotic Pb isotope ratios were different from those of local geogenic Pb. Although the Pb isotope measurements could not unambiguously identify the specific anthropogenic sources of atmospheric Pb in biota, initial evidence points to the importance of fossil fuels currently used in transportation and power generation. Further research should characterize bioavailable chemical species of Pb in aerosols and important emission sources in western Canada.

Since early 2020, the world has faced an unprecedented pandemic caused by the novel COVID-19 virus. In this study, we characterize the impact of the lockdown associated with the pandemic on air quality in six major cities across the state of Florida, namely: Jacksonville, Tallahassee, Gainesville, Orlando, Tampa, and Miami. Hourly measurements of PM₂.₅, ozone, NO₂, SO₂, and CO were provided by the US EPA at thirty sites operated by the Florida Department of Environmental Protection during mid-February to mid-April from 2015 through 2020. To analyze the effect of the pandemic, atmospheric pollutant concentrations in 2020 were compared to historic data at these cities during the same period from 2015 to 2019. Reductions in NO₂ and CO levels were observed across the state in most cities and were attributed to restrictions in mobility and the decrease in vehicle usage amid the lockdown. Likewise, decreases in O₃ concentrations were observed and were related to the prevailing NOₓ-limited regime during this time period. Changes in concentrations of SO₂ exhibited spatial variations, concentrations decreased in northern cities, however an increase was observed in central and southern cities, likely due to increased power generation at facilities primarily in the central and southern regions of the state. PM₂.₅ levels varied temporally during the study and were positively correlated with SO₂ concentrations during the lockdown. In March, reductions in PM₂.₅ levels were observed, however elevations in PM₂.₅ concentrations in April were attributed to long-range transport of pollutants rather than local emissions. This study provides further insight into the impacts of the COVID-19 pandemic on anthropogenic sources from vehicular emissions and power generation in Florida. This work has implications for policies and regulations of vehicular emissions as well as consequences on the use of sustainable energy sources in the state.

The insufficient removal of pollutants and bioelectricity production have become a bottleneck for high-concentration saline wastewater treatment through microbial fuel cell (MFC) technology. Herein, a novel supercapacitor MFC (SC-MFC) was constructed with carbon nanofibers composite electrodes to investigate pollutant removal ability, power generation, and electrochemical properties using real landfill leachate. The possible extracellular electron transfer and nitrogen element conversion pathways in the bioanode were also analyzed. Results showed that the SC-MFC had higher pollutant removal rates (COD: 59.4 ± 1.2%; NH₄⁺-N: 78.2 ± 1.6%; and TN: 77.8 ± 1.2%), smaller internal impedance Rₜ (∼6 Ω), higher exchange current density i₀ (2.1 × 10⁻⁴ A cm⁻²), and a larger catalytic current j₀ (704 μA cm⁻²) with 60% leachate than those with 10% and 20% leachate, resulting in a power output of 298 ± 22 mW m⁻². Ammonium could be incorporated by chemoautotrophic bacteria to produce organic compounds that could be further utilized by heterotrophs to generate power when biodegradable organic matters are depleted. Three conversion pathways of nitrogen might be involved, including NH₄⁺ diffusion from anode to cathode chamber, nitrification, and the denitrification process. Additionally, cyclic voltammetry tests showed that both the direct electron transfer (DET) and the mediator electron transfer in bioanode were involved and dominated by DET. The microbial analysis revealed that the bioanode was dominated by salt-tolerant denitrifying bacteria (38.5%), which was deduced to be the key functional microorganism. The electrochemically active bacteria decreased significantly from 61.7% to 4% over three stages of leachate treatment. Overall, the SC-MFC has demonstrated the potential for wastewater treatment along with energy harvesting and provides a new avenue toward sustainable leachate management.

Problems with PM₂.₅ pollution in the Pearl River Delta (PRD) have been significantly reduced since the Chinese government released a series of emission control policies including the strengthened controls in the 13ᵗʰ Five-Year Plan. This study assessed the efficacy of emission control measures using the Community Multiscale Air Quality (CMAQ) model to provide data-driven support to government decision making, which is becoming increasingly important. This study aimed to quantitatively evaluate the integrated results of proposed policies for controlling PM₂.₅ concentrations. Accordingly, the regional 2015 emission inventory was modified with recently released government data for the PRD, and scenarios for four dynamical emission-reduction policies (S1–S4) were explored. The results show that all four proposed control measures can help to reduce PM₂.₅ concentrations throughout Hong Kong (HK), Macao, and the PRD economic zone (PRD EZ) by 2020. In all cases, reductions in PM₂.₅ concentrations were larger over PRD EZ than over HK. For HK, the predicted annual concentrations of PM₂.₅ were less than 20 μg/m³ for S1–S3 and less than 15 μg/m³ for S4. For Macao, the predicted annual concentrations of PM₂.₅ were less than 25 μg/m³ for S1 and less than 15 μg/m³ up to S3. Regionally, HK had the lowest PM₂.₅ levels, and the area around Foshan had the highest. Controlling the sources of air pollution (i.e., industry, transport, power production, and other sources) within PRD can get most of the PRD EZ region to below 35 μg/m³. Similar national air quality management efforts could reduce PM₂.₅ levels to less than 25 μg/m³ in the PRD EZ and less than 15 μg/m³ in HK. Control measures in S1 led to significant improvement in Shenzhen and HK, but the S3 option brought the greatest improvement for PRD EZ and Macao. The S4 policy option led to substantial reductions, particularly for HK.

Given its wide distribution in the natural environment and global transport potential, mercury (Hg) is regarded as a ubiquitous pollutant. In this study, we carried out nation-wide sampling campaigns across China to investigate the distribution of Hg in agricultural soils. Concentrations of Hg in the soils collected in 2011 and 2016 ranged from 0.04 to 0.69 and 0.06–0.78 mg kg−1, respectively. Based on the data from 2016, the reserve of Hg in the surface arable soils (0–20 cm) in China was 4.1 × 104 metric tons and Chinese cultivated soils accounted for 63.4–364 metric tons of Hg released to the global atmosphere. The soil Hg concentrations were significantly higher than the reference background level, highlighting the impacts of anthropogenic activities. The vertical distribution pattern showed a clear enrichment at the surface and a decrease with depth of the soils. Comparison of calculated geo-accumulation indexes among individual provinces showed that Northwest China had higher levels of Hg contamination than other regions of China, likely due to long-term energy related combustions in the area. Soil Hg level showed strong positive correlations with organic matter contents of soil, as well as the mean annual precipitation and temperature of the sampling locations. The non-carcinogenic human health risks of soil Hg were below the threshold level, but the general risk to the ecosystem was considerable. The increases in Hg accumulation from 2011 to 2016 at provincial level were found to relate to coal combustion, power generation and per capita GDP. This examination of energy consumption and socioeconomic drivers for China's soil Hg reserve increase is critical for direct Hg control by guiding policy-making and targets of technology development in era of rapid economic growth.

Atmospheric PM₂.₅ pollution has become a global issue, and is increasingly being associated with social unrest. As a resource reliant local economy and heavy industry cluster, the North China region has become China's greatest emitter, and the source of much pollution spillover to outside regions. To address this issue, the current study investigates the transfers of embodied PM₂.₅ emissions to and from the North China region (which is taken to include Hebei, Henan, Shandong, and Shanxi, and is referred to here as HHSS). The study uses a top-down pollutant emission inventory and environmentally extended multi-regional input-output (EE-MRIO) model. The results indicate that the HHSS area exported a total of 660 Gg of embodied PM₂.₅ to other domestic provinces, mainly producing outflows to China's central coastal area (Jiangsu, Zhejiang, and Shanghai) and the Beijing-Tianjin region. HHSS also imported 224 Gg of embodied PM₂.₅ from other domestic regions, primarily from Inner Mongolia and the northeast. Furthermore, the transfer of embodied emissions often occurred between geographically adjacent areas to save costs; Beijing and Tianjin mainly transferred embodied pollution to Hebei and Shanxi, whilst Jiangsu, Shanghai, and Zhejiang tended to import embodied air pollutants from Shandong and Henan. At the sectoral level, the melting and pressing of metals, the production of non-metallic products, and electric and heat power production were the three dominant economic sectors for PM₂.₅ emissions, together accounting for 81% of total discharges. Capital formation played a key role in outflows (75%) in all sectors. Moreover, the virtual pollutant emissions exported to foreign countries also significantly affected HHSS′ discharges significantly, making up 340 Gg. Allocating responsibility for some proportion of HHSS′ emissions to the Beijing-Tianjin area and the central coastal provinces may be an effective approach for mitigating releases in HHSS.