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  • MDPI AG  (3)
  • Zhang, Jiaquan  (3)
  • 1
    In: Atmosphere, MDPI AG, Vol. 8, No. 11 ( 2017-11-08), p. 213-
    Abstract: PM10 samples were collected from Huangshi (HS) city, Central China during April 2012 to March 2013, and were analyzed for short-chain saturated dicarboxylic acids (diacids) using a capillary gas chromatograph (GC). We found that oxalic acid (C2, 318 ± 104 ng·m−3) was the most abundant diacid species, followed by malonic acid (C3, 25.4 ± 9.11 ng·m−3) and succinic acid (C4, 2.09 ± 0.52 ng·m−3). The concentrations of C2 and C4 diacids were highest in winter, followed by summer and spring, and lowest in autumn. C3 diacid was decreased in the order of summer 〉 winter 〉 autumn 〉 spring. Further, the seasonal variations of WSOC (water-soluble organic carbon)- and OC (organic carbon)-normalized diacid concentrations were similar to those of diacid concentrations, suggesting that both primary emission and secondary production are important sources for diacids in Huangshi (HS) aerosols. Strong correlations were found among C2 diacid and the three ions SO42−, NO3−, and NH4+ in summer and winter, suggesting that the species could undergo a similar secondary oxidation processing. C2 had good correlation with K+ in summer and autumn, which indicates an enhanced contribution of combustion sources for C2 diacid. Moreover, according to the ratio of C2/K+, we can conclude that C2 diacid should be formed by a secondary reaction of biomass combustion in HS aerosols, especially in summer and autumn. The ratios of C2/C4 and C3/C4 were compared with those reported in other sites, and the results suggest that HS aerosols should be more photochemically aged than at other urban areas. Principal component analysis of diacids and selected water-soluble inorganic ions over four seasons suggests that HS aerosols are influenced not only from primary emission, but also from secondary reaction. According to the linear relation between C2 and C3 diacids, the results indicate that C2 diacid is formed from the oxidation of hydrocarbon compounds in spring, while it is from the oxidation of C3 and C4 diacids in summer, autumn, and winter.
    Type of Medium: Online Resource
    ISSN: 2073-4433
    Language: English
    Publisher: MDPI AG
    Publication Date: 2017
    detail.hit.zdb_id: 2605928-9
    SSG: 23
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  • 2
    In: Atmosphere, MDPI AG, Vol. 8, No. 4 ( 2017-04-08), p. 74-
    Abstract: A total of 61 PM10 samples in Huangshi (HS), Central China, were collected every sixth day from April 2012 to March 2013 and were analyzed for water-soluble inorganic ions (WSIIs) by ion chromatography. The sum of three major ions (SO42−, NO3−, and NH4+) accounted for 75.8% of the total WSIIs on average. The results of a non-parametric test (Kruskal-Wallis) show that, except for Na+ (p 〉 0.05), the other ions present a distinctly seasonal variation with a statistically significant difference (p 〈 0.05). The minimum concentrations of all ions were found in summer, while the maximum values presented in autumn (for Ca2+) and winter (for Cl−, NO3−, SO42−, K+, NH4+, Mg2+). Based on the highest ratio of Cl−/Na+ (3.02) and the highest concentration of K (4.37 μg·m−3), Ba (0.37 μg·m−3), and Sr (0.07 μg·m−3) in February 2013, it can be concluded that firework powders have aggravated the haze weather during the Spring Festival of 2013. The micro-equivalent concentrations of cations and anions were calculated and the comparisons between the calculated and measured NH4+ concentrations were conducted. The results illustrate that aerosol particles in HS are acidic and there may exist some other cationic ions not detected in this study. An obvious positive correlation and good linear regression among WSIIs suggest that the chemical forms in HS aerosols show a great variety of combinations, such as NH4NO3, NH4HSO4, (NH4)2SO4, NH4Cl, KCl, KNO3, NaCl, NaNO3, Ca(NO3)2, CaSO4, MgCl2, Mg(NO3)2, and MgSO4. The WSIIs have large positive correlation and linear regression with the elements, suggesting that WSIIs in mining cities are strongly influenced by element constituents. Principal component analysis implies that WSIIs in PM10 are probably from three sources. NH4+, Mg2+, NO3−, K and K+, Cl− and Cl, SO42−, and S accounted for 46.9% of the total variances, suggesting likely anthropogenic sources, especially coal combustion, vehicular exhaust, and biomass burning. Mg accounted for 23.3% of the total variances and Ca2+ and Ca explained 18.1% of the total variances, demonstrating that another important source is mineral dust from both natural and anthropogenic sources.
    Type of Medium: Online Resource
    ISSN: 2073-4433
    Language: English
    Publisher: MDPI AG
    Publication Date: 2017
    detail.hit.zdb_id: 2605928-9
    SSG: 23
    Location Call Number Limitation Availability
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  • 3
    In: International Journal of Environmental Research and Public Health, MDPI AG, Vol. 19, No. 20 ( 2022-10-14), p. 13227-
    Abstract: To develop accurate air pollution control policies, it is necessary to determine the sources of different types of fugitive dust in mining and metallurgy areas. A method integrating principal component analysis and a positive matrix factorization model was used to identify the potential sources of heavy metals (HMs) in five different types of fugitive dust. The results showed accumulation of Mn, Fe, and Cu can be caused by natural geological processes, which contributed 38.55% of HMs. The Ni and Co can be released from multiple transport pathways and accumulated through local deposition, which contributed 29.27%. Mining-related activities contributed 20.11% of the HMs and showed a relatively high accumulation of As, Sn, Zn, and Cr, while traffic-related emissions contributed the rest of the HMs and were responsible for the enrichment in Pb and Cd. The co-applied source-identification models improved the precision of the identification of sources, which revealed that the local geological background and mining-related activities were mainly responsible for the accumulation of HMs in the area. The findings can help the government develop targeted control strategies for HM dispersion efficiency.
    Type of Medium: Online Resource
    ISSN: 1660-4601
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2175195-X
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