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This study aims to focus on the submicron particles (with diameter of 0.2-1.0 μm) of the ambient air from a coal-fired power plant. A systematic examination of their morphology, particle size and chemical element will be analyzed, so as to provide more scientific information and theoretical basis for the formation and control method of inhalable particles, as well as data support for environmental impact and ecological effects assessments.

In this paper, the morphology, size distribution and elemental characteristics of submicron particles from ambient air of a coal-fired power plant are studied by single particle analysis.

The results show that atmospheric particles in coal-fired power plant are mainly spherical particles, and most of them are soot aggregates adhered or coated with other particles with few rectangle particles. The particles collected in the afternoon and evening are mainly of spherical particles, and small-sized particles collected in the morning are mainly spherical ones, while the overall concentration is larger than that of the spherical particles in the size range above 0.5 μm. The results indicated that the larger-sized spherical particles have a lower concentration.

Coal-fired power plants are still the main supply of electricity in China, but the inhalable particles, especially sub-micron particles (0.1-1.0 μm) cannot be effectively captured by the dust removal device from the coal-fired power plant. Thus, a large amount of inhalable particles is emitted into the atmosphere, becoming the major air pollutants in China.

Severe airborne particulate pollution frequently occurs over the North China Plain (NCP) region in recent years. To better understand the characteristics of carbonaceous components in particulate matter (PM) over the NCP region.

PM samples were collected at a typical area affected by industrial emissions in Handan, in January 2016. The concentrations of organic carbon (OC) and elemental carbon (EC) in PM of different size ranges (i.e. PM_2.5, PM₁₀ and TSP) were measured. The concentrations of secondary organic carbon (SOC) were estimated by the EC tracer method.

The results show that the concentration of OC ranged from 14.9 μg m⁻³ to 108.4 μg m⁻³, and that of EC ranged from 4.0 μg m⁻³ to 19.4μg m⁻³, when PM_2.5 changed from 58.0μg m⁻³ to 251.1μg m⁻³ during haze days, and the carbonaceous aerosols most distributed in PM_2.5 rather than large fraction. The concentrations of OC and EC PM_2.5 correlated better (r = 0.7) than in PM_2.5−10 and PM_>10, implying that primary emissions were dominant sources of OC and EC in PM_2.5. The mean ratios of OC/EC in PM_2.5, PM_2.5–10 and PM_>10 were 4.4 ± 2.1, 3.6 ± 0.9 and 1.9 ± 0.7, respectively. Based on estimation, SOC accounted for 16.3%, 22.0% and 9.1% in PM_2.5, PM_2.5–10 and PM_>10 respectively.

The ratio of SOC/OC (48.2%) in PM_2.5 was higher in Handan than those (28%–32%) in other megacities, e.g. Beijing, Tianjin and Shijiazhuang in the NCP, suggesting that the formation of SOC contributed significantly to OC. The mean mass absorption efficiencies of EC (MACEC) in PM₁₀ and TSP were 3.4 m² g⁻¹ (1.9–6.6 m² g⁻¹) and 2.9 m² g⁻¹ (1.6–5.6 m² g⁻¹), respectively, both of which had similar variation patterns to those of OC/EC and SOC/OC.

This study aims to acquire a better understanding on the characteristics and risks of heavy metals (HMs) in PM_2.5 from an industrial city – Handan, China.

PM_2.5 samples were collected on the basis of daytime and nighttime at the state controlling air sampling site in Handan city. Ten metal elements (V, Cr, Mn, Fe, Ni, Cu, Rb, Sr, Cd and Ba) in PM_2.5 were determined with an inductively coupled plasma mass spectrometry. The pollution levels of metals were characterized by enrichment factors, and the sources of metals were identified with principle component analysis and cluster analysis. The ecological and health risks of metals were assessed using ecological and health risk indexes.

Results showed that the highest and lowest PM_2.5 concentration appeared in winter and summer, respectively. The concentration of PM_2.5 at night was higher than in the daytime in winter, yet it is the opposite in other seasons. The total mass concentration of detected metals was the highest in winter, and the total mass concentration in the daytime was higher than at night in all four seasons. The elements V, Rb, Sr and Ba exhibited a deficient contamination level; Cr, Ni and Cu exhibited a moderate contamination level; while Fe and Cd were at an extreme contamination level. The metals in PM_2.5 originated from a mixture source of fossil fuel combustion and manufacture and use of metallic substances (34.04%), natural source (26.01%) and construction and traffic-related road dust (17.58%). Results from the ecological risk model showed that the ecological risk of metals was very high, especially risks related to Cd. Health risk model presented that both the non-carcinogenic and carcinogenic risk coefficients of metals were above the tolerance level of the human body.

The significance of the study is to further know the pollution characteristics of PM_2.5 and related HMs in Handan city, and to provide references for ensuring local resident health and ecological environment.

In this paper, the geochemical characteristics of the trace elements of the No. 6 coal seam from Tanggongta mine, Jungar Coalfield, were studied using the methods of an energydispersive X-ray spectrometer (SEM-EDX) analysis, X-ray powder diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence spectrometric (XRF) techniques. The content of sulfur ranges from 0.09% to 2.83% (1.09% on average). The ash is from 11.70% to 31.47% (20.72% on average), and the moisture is from 2.72% to 6.82% (4.72% on average). The main minerals are kaolinite, carbonate minerals and pyrite. Compared with the average values of Chinese coal, the contents of Ga, Cd, Tl, Li, Sr, and Ag are high. Compared with the values of world coal, Li and Sr are found at high levels. The distribution mode of the REE shows that LREE is concentrated, but HREE is relatively low. The Yinshan Oldland should be the most likely source of the coal’s Li. The bauxite of the Benxi formation could be another source of the coal’s Li in the NE Jungar Coalfield.

The characteristics of fine aerosol particles were investigated at an urban site in Beijing during an atmospheric pollution accumulation process. The organics, sulfate and BC were the dominant components in fine particles in the clear air, and the concentrations of organics, sulfate, nitrate and ammonium increased during the haze formation. The mass concentrations of primary species (chloride and BC) in the clear air were similar to those in the haze. The morphology, mixing state and aging status of fine particles in the clear air were different from those in the haze. Accumulation secondary particles were detected with high frequency and accumulation secondary particles with coating were rare in all the samples. The frequency of soot particles with coating in the clear air was lower than that in the haze. The number ratio of accumulation secondary particles to soot containing particles changed from 3:1 in clear air to 2:3 in the haze. These results indicated that the number frequency of accumulation secondary particles decreased while that of the soot containing particles increased with the air pollutants accumulating. The core-shell ratio of coated soot particles ranged between 0.1–0.6 was 62% in the clear air, and 82% in the haze. The mode sizes for the core and the shell of soot particles were 0.35 μm and 0.55 μm in the clear air, and 0.35 μm and 1.0 μm in the haze, respectively. The mean diameters of the core and the shell were 0.3 μm and was 0.6 μm in the clear air, and 0.4 μm and 1.0 μm in the haze, respectively. These results indicated that with the air pollution accumulating, the frequency of accumulation secondary particles decreased while the soot containing particles increased. The aging process of soot particles was stronger in the haze, and resulted in greater hygroscopicity for soot particles in the haze.

Numerous smog events have occurred in recent years in China. Their hazards in mining and industrial cities are more serious than clear days. The samples were collected in the mining and industrial city of Handan. During the smog episode, PM₁₀ and PM_2.5 concentrations reach up to 980 μg/m³ and 660 μg/m³, respectively. Under SEM (scanning electron microscope) analysis, the particles consist of soot, fly ash and minerals, which could be from coal mines, power plants, steel mills and auto exhausts. Compared with the samples collected on a clear day, the increased PM₁₀ particles are mainly composed of organic matter, especially aromatic compounds. The Pb content in PM₁₀ of the smog day reaches 507.4 ng/m³ and could be caused by vehicle emissions.

This paper describes the organic geochemical characteristics and their roles on barium enrichment in the No. 2 Coal from Huanglong Jurassic Coalfield, China. A total of 18 bench samples were taken from Huangling Mine 2. The average content of barium (3701 mg/kg) was about 23 times higher than that of common world coals. Terrestrial higher plants were the main coal-forming parent material. Relying on the parameters of OEP, Pr/Ph and so on, there is little correlation between organic geochemical characteristics and barium enrichment. Therefore, organic material has little influence on the process of coal-forming and the enrichment of barium.

This paper aims to elucidate the geochemical characteristics of the hydrothermally altered rocks with gold mineralization and the elemental transfers in hydrothermal alteration hosted in alkaline complex in Hongshan area, Taihang Orogen, North China, and preliminarily discuss the relationship between the gold mineralization and the hydrothermal alteration.

Based on detailed field investigation, sampling and petrographical observation, major oxides and trace elements of nine rock samples are analyzed, and the method of mass balance equation is used in calculation of the elemental transfer.

Three alteration stages in the Hongshan area are identified, which are the early, main and late alterations. The early one is characteristic of extensive pyritization in the complex, which is related to the mantle-derived magmas and occurs before gold mineralization. The main one is characterized by developing a great deal of altered rock in fracture zones with the gain of many elements and the loss of a few elements. The late one is dominated by limonitization, that is limonite replacing the early pyrite or Fe₂O₃ replacing FeO in rocks. In the main alteration, the altered rocks obviously gain fluid component (LOI, i.e. loss on ignition) and elements such as V, As, Rb, Au, La, Ce and Nd and total rare earth elements (REEs). Elements such as K, Fe, Cu, Zn, Y, Mo, Sb, W, Re and U are gained in some altered rocks. Na and Sr are lost in all altered rocks, and Th and Bi are lost in some ones in the meantime. The following elements: Si, Mg, Mn, Ca, Li, Sc, Cr, Co, Ni, Zr, Ag, Ba and Hg show either gain or loss in different altered rocks. Au is notably enriched in the hydrothermal alteration. The elemental gain or loss in the altered rocks indicates that the main mineralization develops extensive de-alkalinization, local potassic metasomatism, silicification or desilicification.