Search Results (247)

Solid fuels are still widely used in household heating in Europe and North America. Emissions from boilers are released in proximity to people. Therefore, there is a need to minimise the toxicity of emissions affecting human health to the greatest extent possible. This study compares the genotoxic potential of the emissions of four boilers of modern and old design (automatic, gasification, down-draft, over-fire) operating at reduced output to simulate the real-life combustion fed by various fossil and renewable solid fuels (hard coal, brown coal, brown coal briquettes, wood pellets, wet and dry spruce). Organic emissions were tested for genotoxic potential by analysing bulky DNA adducts and 8-oxo-dG adduct induction. There was no consistent genotoxic pattern among the fuels used within the boilers. Genotoxicity was strongly correlated with polycyclic aromatic hydrocarbon (PAH) content, and even stronger correlation was observed with particulate matter (PM). In all measured variables (PM, PAHs, genotoxicity), the technology of the boilers was a more important factor in determining the genotoxic potential than the fuels burned. The highest levels of both bulky and 8-oxo-dG DNA adducts were induced by organics originating from the over-fire boiler, while the automatic boiler exhibited genotoxic potential that was ~1000- and 100-fold lower, respectively. Full article

The occurrence of haze pollution significantly deteriorates air quality and threatens human health, yet persistent knowledge gaps in real-time source apportionment of fine particulate matter (PM_2.5) hinder sustained improvements in atmospheric pollution conditions. Thus, this study employed single-particle aerosol mass spectrometry (SPAMS) to investigate PM_2.5 sources and dynamics during winter haze episodes in Yinchuan, Northwest China. Results showed that the average PM_2.5 concentration was 57 μg·m⁻³, peaking at 218 μg·m⁻³. PM_2.5 was dominated by organic carbon (OC, 17.3%), mixed carbonaceous particles (ECOC, 17.0%), and elemental carbon (EC, 14.3%). The primary sources were coal combustion (26.4%), fugitive dust (25.8%), and vehicle emissions (19.1%). Residential coal burning dominated coal emissions (80.9%), highlighting inefficient decentralized heating. Source contributions showed distinct diurnal patterns: coal combustion peaked nocturnally (29.3% at 09:00) due to heating and inversions, fugitive dust rose at night (28.6% at 19:00) from construction and low winds, and vehicle emissions aligned with traffic (17.5% at 07:00). Haze episodes were driven by synergistic increases in local coal (+4.0%), dust (+2.7%), and vehicle (+2.1%) emissions, compounded by regional transport (10.1–36.7%) of aged particles from northwestern zones. Fugitive dust correlated with sulfur dioxide (SO₂) and ozone (O₃) (p < 0.01), suggesting roles as carriers and reactive interfaces. Findings confirm local emission dominance with spatiotemporal heterogeneity and regional transport influence. SPAMS effectively resolved short-term pollution dynamics, providing critical insights for targeted air quality management in arid regions. Full article

Reverse osmosis (RO) concentrated water can be effectively treated with catalytic ozone oxidation technology, an effective advanced oxidation process. In order to provide a thorough reference for the safe treatment and reuse of RO concentrated water, this paper examines the properties of RO concentrated water, such as its high salt content, high levels of organic pollutants, and low biochemistry. It also examines the mechanism of its role in treating RO concentrated water and combs through its applications in municipal, petrochemical, coal chemical, industrial parks, and other industries. The study demonstrates that ozone oxidation technology can efficiently eliminate the organic matter that is difficult to break down in RO concentrated water and lower treatment energy consumption; however, issues with free radical inhibitor interference, catalyst recovery, and stability still affect its use. Future research into multi-technology synergistic processes, the development of stable and effective non-homogeneous catalysts, and the promotion of their use at the “zero discharge” scale for industrial wastewater are all imperative. Full article

Shale and coal in the transitional marine–continental facies of the Ordos Basin serve as unconventional natural gas reservoirs, with their pore structures controlling gas adsorption characteristics and occurrence states. To quantitatively characterize the pore structure features and differences between these two reservoirs, this study takes the Shanxi Formation shale and coal in the Daning–Jixian area on the eastern margin of the Ordos Basin as examples. Field-emission scanning electron microscopy (FE-SEM), high-pressure mercury intrusion, low-temperature N₂ adsorption, and low-pressure CO₂ adsorption experiments were employed to analyze and compare the full-scale pore structures of the shale and coal reservoirs. Combined with methane isothermal adsorption experiments, the gas adsorption capacity and its differences in these reservoirs were investigated. The results indicate that the average total organic carbon (TOC) content of shale is 2.66%, with well-developed organic pores, inorganic pores, and microfractures. Organic pores are the most common, typically occurring densely and in clusters. The average TOC content of coal is 74.22%, with organic gas pores being the dominant pore type, significantly larger in diameter than those in transitional marine–continental facies shale and marine shale. In coal, micropores contribute the most to pore volume, while mesopores and macropores contribute less. In shale, mesopores dominate, followed by micropores, with macropores being underdeveloped. Both coal and shale exhibit a high SSA primarily contributed by micropores, with organic matter serving as the material basis for micropore development. The methane adsorption capacity of coal is 8–29 times higher than that of shale. Coal contains abundant organic micropores, providing a large SSA and numerous adsorption sites for methane, facilitating gas adsorption and storage. This study comprehensively reveals the similarities and differences in pore structures between transitional marine–continental facies shale and coal reservoirs in the Ordos Basin at the microscale, providing a scientific basis for the precise evaluation and development of unconventional oil and gas resources. Full article

This study investigates the emission characteristics and environmental impacts of pollutants from bagasse-fired biomass boilers through the integrated field monitoring of two sugarcane processing plants in Guangxi, China. Comprehensive analyses of flue gas components, including PM_2.5, NOx, CO, heavy metals, VOCs, HCl, and HF, revealed distinct physicochemical and emission profiles. Bagasse exhibited lower C, H, and S content but higher moisture (47~53%) and O (24~30%) levels compared to coal, reducing the calorific values (8.93~11.89 MJ/kg). Particulate matter removal efficiency exceeded 98% (water film dust collector) and 95% (bag filter), while NOx removal varied (10~56%) due to water solubility differences. Heavy metals (Cu, Cr, Ni, Pb) in fuel migrated to fly ash and flue gas, with Hg and Mn showing notable volatility. VOC speciation identified oxygenated compounds (OVOCs, 87%) as dominant in small boilers, while aromatics (60%) and alkenes (34%) prevailed in larger systems. Ozone formation potential (OFP: 3.34~4.39 mg/m³) and secondary organic aerosol formation potential (SOAFP: 0.33~1.9 mg/m³) highlighted aromatic hydrocarbons (e.g., benzene, xylene) as critical contributors to secondary pollution. Despite compliance with current emission standards (e.g., PM < 20 mg/m³), elevated CO (>1000 mg/m³) in large boilers indicated incomplete combustion. This work underscores the necessity of tailored control strategies for OVOCs, aromatics, and heavy metals, advocating for stricter fuel quality and clear emission standards to align biomass energy utilization with environmental sustainability goals. Full article

The integration of different agroecological practices could significantly mitigate the impact of climate change. Therefore, a 2-year field experiment on organic zucchini was carried out to study the effects of clover (Trifolium alexandrinum L.) cover crop management (green manure, GM vs. flattening using a roller crimper, RC), compared to a control without cover (CT). This agroecological practice was tested in combination with the following different fertilizer treatments: T1. compost produced by co-composting coal mining wastes with municipal organic wastes compost plus urea; T2. compost produced with the same matrices as T1, replacing urea with lawn mowing residues; T3. non-composted mixture of the industrial matrices; T4. on-farm compost obtained from crop residues. The GM management showed the highest marketable yield and aboveground biomass of zucchini, with both values higher by approximately 38% than those recorded in CT. The T1, T2, and T3 treatments showed higher SOC values compared to T4 in both years, with a gradual increase in SOC over time. The residual effect of fertilization on SOC showed a smaller reduction in T3 and T4 than in T1 and T2, in comparison with the levels recorded during the fertilization years, indicating a higher persistence of the applied organic matter in these treatments. The findings of this study pointed out that combining organic fertilization and cover cropping is an effective agroecological practice to maintain adequate zucchini yields and enhance SOC levels in the Mediterranean environment. Full article

The first coalification jump (FCJ) has a significant effect on changes in the microstructural properties of coal and plays a crucial role in understanding the efficient utilization of low-rank coal. One lignite (QSY-2), two subbituminous (MHJ-10 and YCW-2), and three high-volatile A-grade bituminous coals (YX-12, JF-18, and HY-5) from the Ningdong coalfield were selected for research, avoiding the influence of regional geology. The evolution characteristics of the microstructures before and after the FCJ were investigated via spectroscopic experiments. The complex and unstable molecular structure of low-rank coal gradually decomposes and polymerizes at 350 °C. The aliphatic structure shows a V-shaped change trend as metamorphism increases. The inflection point is around an R_o of 0.6%. Demethylation and polymerization occur simultaneously during the FCJ. The reconnection of benzene substances with the aromatic ring increases the density of aromatic rings in the YCW-2 sample, significantly enhancing its aromaticity. The removal of oxygen-containing functional groups, especially methoxy and carbonyl groups, provides the possibility for the formation of CH₄ and CO₂ during the metamorphosis of lignite to subbituminous coal. Furthermore, high temperatures result in a loss of moisture content during the FCJ, which is the primary factor leading to a reduction in the hydroxyl content in coal. The selected samples are primarily composed of organic matter, with low levels of heteroatoms in the coal. It is preliminarily determined that coalification is not significantly affected. This study provides a theoretical foundation for investigating the molecular structure evolution of low-rank coal during the FCJ. Full article

The high concentration of arsenic in coal does great harm to the environment. It is important to research the occurrence mode of As in coal to promote the removal of As in coal and understand the migration and transformation of As in coal. In this work, eleven samples from the Hanshuiquan coal mine, in the Santanghu Coalfield, were tested by X-ray diffraction (XRD) and Scanning Electron Microscopy with an Energy Dispersive Spectrometer (SEM-EDS). The results show that maximum arsenic content in the coal seam was 108.37 μg/g, which was 13 times more than that of the world coal, and 28 times more than that of the Chinese coal. Through X-ray diffraction (XRD) experiments, ojuelaite and scorodite were found in the samples. Scanning Electron Microscopy (SEM) and an Energy Dispersive Spectrometer (EDS) were used to determine the occurrence location of the arsenic elements. In combination with geochemistry and mineralogy theory, the occurrence modes of the arsenic were studied in detail. The occurrence modes of arsenic in coal from the study area are dominated by sulfide-bound arsenic. At the same time, it was found that arsenic in the study area might occur in the form of arsenate containing zinc and organic bound arsenic. Previous studies and this work have shown that (1) arsenic in coal is predominantly in the form of pyrite, and (2) arsenic in coal is associated with organic matter in low-rank coal and to a lesser extent in high-rank coal. Understanding the occurrence modes of arsenic in coal is of great significance because it has significant impacts on coal mining, preparation, combustion, and utilization, and has adverse effects on the environment and human health. Full article

Coal gangue, a primary byproduct of coal mining, causes significant environmental harm due to its improper utilization. This research proposes integrating microalgae with coal gangue-derived ecological products to improve soil conditions in ecologically vulnerable coal-mining regions. A field-scale experiment at the Jintong Coal Mine tested soils amended with varying proportions of a coal gangue ecological matrix (0%, 10%, 30%, and 50%), with and without microalgae inoculation. The results demonstrated that coal gangue addition caused undesirable soil pH decreases (11.30~42.20%) while increasing total dissolved solids (506.88~524.93%) and organic matter (8.51~46.81%). These effects were mitigated by the presence of microalgae. Microalgae play a role in regulating soil nutrient profiles, enhancing enzymatic activities, and modulating the microbial community structure. For example, they restored catalase activity under the stress imposed by coal gangue and stimulated urease activity at higher coal gangue proportions. Plant growth trials revealed that adding 30% coal gangue or combining coal gangue with microalgae significantly promoted the growth of Medicago sativa L. In summary, coupling the coal gangue ecological matrix with microalgae effectively enhances soil quality. Maintaining the coal gangue addition at 30% or less in conjunction with microalgae application represents an optimal approach for soil improvement in mining areas. Full article

Soil salinization in coastal areas is a serious problem restricting agricultural development. This field study aimed to explore the effects of flue gas desulfurization gypsum (FGDG) and coal fly ash (CFA) in combination with irrigation on coastal saline soils in China. Six different treatments (C1–C4: FGDG 4.5–15.0 t/hm²; C5 and C6: FGDG 4.5 t/hm² combined with CFA 2.0 and 3.5 t/hm²) were established, and soil properties such as pH, electrical conductivity (EC), and organic matter (OM) content were analyzed. The results showed that compared with the control group, the addition of FGDG (4.5 t/hm² to 15 t/hm²) slightly increased the soil pH, and the combined application of FGDG and CFA made the soil pH closer to neutral. The application of FGDG combined with two rounds of irrigation could reduce the soil EC, and the mixed application of FGDG and CFA further reduced the soil EC by about 6.7% in the 0–20 cm layer. The application of FGDG combined with irrigation showed no significant effect on the soil OM content. In general, the moderate application of FGDG and CFA can effectively improve the physicochemical properties of soil, potentially contributing to more sustainable agricultural practices in coastal regions. Full article

The Yan’an Formation in the Liupanshan Basin hosts substantial coal and oil shale resources. However, coal and oil shale often exhibit different types of associated or syngenetic combinations, which makes it difficult to recognize coal and oil shales, and research on the patterns of development of coal and oil shales is lacking. In this study, field outcrop, core, logging, and analytical data are comprehensively utilized to describe the characteristics of coal and oil shale, classify their syngenetic combinations, and establish a developmental model. Analytical results from the Tanshan area reveal that coal exhibits a lower density and higher oil content than oil shale. Specifically, coal shows oil contents ranging from 7.22% to 13.10% and ash contents of 8.25–35.66%, whereas oil shale displays lower oil contents (3.88–6.98%) and significantly higher ash contents (42.28–80.79%). The oil and ash contents of both coal and oil shale in the Tanshan area show a negative correlation, though this correlation is significantly stronger in coal than in oil shale. In long-range gamma-ray and resistivity logs, coal exhibits substantially higher values compared to oil shale, whereas in density logs, oil shale shows greater values than coal. Acoustic time difference logging reveals marginally higher values for coal than for oil shale, though the difference is minimal. There are five combination types between coal and oil shale in this area. The oil shale formed in a warm, humid, highly reducing lacustrine environment within relatively deep-water bodies, while coal developed in swampy shallow-water environments; both derive organic matter from higher plants. Variations in depositional settings and environmental conditions resulted in five distinct combination types of coal and oil shale. Full article

Elucidating the microbial–hydrochemical interactions in distinct functional zones of coal mines holds significant implications for groundwater pollution mitigation strategies in mining regions. Taking Xinji No. 2 Coal Mine as an example, 15 water samples (including surface water, goaf water, sump water, working face drainage, rock roadway water, and coal roadway water) were collected from six surface and underground areas for hydrochemical and microbial detection analysis. The results show that bacterial genera such as Exiguobacterium and Mycobacterium cannot adapt to high-salinity environments with elevated K⁺ + Na⁺ concentrations, showing negative correlation with TDS. Microbial communities related to sulfate serve as important indicators for microbial technology-based pollution control in coal mine groundwater, where sulfate-reducing bacteria (e.g., norank_f__Desulfuromonadaceae) can reduce SO₄²⁻ concentrations and improve mine water quality. Low dissolved oxygen (DO) concentrations lead to decreased abundance of aerobic microorganisms, hindering the formation of stable microbial communities in mines. Affected by mine water quality, the confluence of mine drainage into rivers results in HCO₃⁻ and SO₄²⁻ concentrations at the confluence being higher than upstream, which gradually return to upstream concentrations after entering the downstream. However, due to the influx of nitrogen cycle-related bacteria and organic matter from mine water into surface water, increased microbial physiological activities and carbon sources cause NO₃⁻ concentrations to increase more than tenfold. The formation stages of mine water quality exhibit regional characteristics, with goaf areas showing distinct hydrochemical components and microbial communities compared to other zones. Based on this research, new microbial approaches for groundwater pollution control in coal mining areas are proposed: (1) selecting and cultivating functional microorganisms (such as SRB and organic matter-degrading bacteria) to develop biological materials for mine water remediation; (2) regulating the transformation of elements by adjusting carbon sources and oxygen supply according to indigenous microbial requirements, thereby reducing pollutant concentrations in water bodies. Full article

Understanding soil properties that govern physicochemical and biological processes is essential for achieving high crop quality and yield. Organic matter is an important element of soil fertility and fertility in vegetable cultivation. In the process of decomposition of organic matter in the soil, humus of various quality is formed. The quality of humus depends on the content of individual acids (fulvic, humic and hymatomalanic acids) in it, which can affect the binding–chelation of heavy metals, limiting their availability to plants. The conducted studies determined the effect of adding organic matter (high peat, brown coal and wheat straw) to mineral soil on nickel detoxification in radish, its yield, nitrogen management and chloroplast pigments. The studies were conducted for three years in a greenhouse in a container system. The tested substrates were contaminated with nickel in the amount of 50, 75 and 100 mg dm⁻³. It was found that introducing organic matter into mineral soil can affect the reduction as well as the increase in nickel content in edible parts of radish. The type of organic material introduced into mineral soil as a source of organic matter has a significant impact on nickel content in radish. It was shown that nitrate reductase activity (NR) depends to a large extent on the substrate in which the plants are grown as well as on the applied dose of nickel. A similar relationship was demonstrated in the case of changes in the level of chloroplast pigments (chlorophyll a, chlorophyll b and carotenoids). Full article

The present study aims to determine the concentrations and forms of Copper (Cu), Lead (Pb), Zinc (Zn), Chromium (Cr), Cadmium (Cd), and Arsenic (As) in water and sediments of the Xutuan mining area. The geoaccumulation index (Igeo) and ecological risk assessment coding (RAC) methods were used to assess heavy metal pollution levels and ecological risks in sediments. The positive matrix factorization (PMF) model and the absolute principal component score-multiple linear regression (APCS-MLR) model were used to quantitatively analyze the sources of heavy metals in the evaluated sediments. The results showed good water quality in the mining area. Cu, Cr, Zn, and As in the sediments were mainly in the residual form, while Cd and Pb were mainly in the organic matter combined form. The Igeo and RAC results showed that the Cd pollution degree and ecological risk were higher in the sediments. The APCS-MLR and PMF models analyzed the contributions of natural sources (72.5% and 25.1%) and anthropogenic sources, respectively, while the PMF further distinguished the contributions of coal mining (26.4%), agricultural (21.44%), and traffic (27.05%) sources. Full article

Coal gangue (CG) has become a critical environmental challenge in China, with nearly one billion tons produced annually. To address this challenge while simultaneously supplementing soil resources during mine ecological restoration, a novel process is proposed to convert CG into CG-based artificial soil (CGAS) using a microbial treatment method. This study examined the effects of local microbial agents (LMAs), commercial microbial agents (CMAs), and fly ash (FA) on key soil properties of CGAS, such as organic matter (OM) content, humic acid (HA) content, and water-holding capacity. Additionally, the mechanisms underlying aggregate formation in CGAS were investigated. The results showed that the synergistic effect of LMAs and FA significantly enhanced the essential quality properties of CGAS. In particular, the HA content increased by 2.06 times compared with untreated CG, the proportion of water-stable macroaggregates increased to 11.46%, and the bulk density decreased by 39.71%, achieving an optimal level of 1.30 g/cm³. Analysis of phase compositions, surface functional group characterization, and microstructural examination indicated that organic binders such as HA, inorganic binders such as calcium carbonate and gypsum, and the bonding effect of spherical particles of FA played significant roles in forming a stable and healthy soil structure in CGAS. Full article