Уточнить поиск
Результаты 1-10 из 191
Occurrence of chlorinated and brominated polycyclic aromatic hydrocarbons from electric arc furnace for steelmaking
2022
Yang, Lili | Shen, Jia | Zheng, Minghui | Yang, Qiuting | Li, Da | Liu, Guorui
Chlorinated and brominated polycyclic aromatic hydrocarbons (Cl/Br-PAHs) are persistent organic pollutants with potential carcinogenic toxicities that are even higher than those of their parent PAH congeners. Current knowledge of Cl/Br-PAH sources and emission characteristics is lacking. Electric arc furnace (EAF) steelmaking is a potential source for Cl/Br-PAHs, considering that preheating of raw materials before they enter the EAF could produce suitable conditions for Cl/Br-PAHs formation. In this field study, we identified EAFs as an important source of Cl/Br-PAHs and clarified their emission concentrations, fingerprints by gas chromatography coupled with high-resolution magnetic mass spectrometry. Potential formation mechanisms of Cl/Br-PAHs were also proposed. The mass concentration ranges for Σ₁₈Cl-PAHs and Σ₁₈Br-PAHs in stack gas were 25.85–4191 ng Nm⁻³ and 1.02–341 ng Nm⁻³, respectively. The variation of concentration indicated that the steel scrap composition greatly affected the production of Cl/Br-PAHs. The congener ratios including 6-chlorobenzo [a]pyrene/3-chlorofluoranthene and 1-chloroanthracene/1-chloropyrene could be used to estimate the influence of industrial sources on Cl-PAH occurrences in the air. Ring structure growth was the dominant formation pathway for Cl/Br-PAHs, distinctly different from dioxin formation mechanisms dominated by precursor dimerization and chlorination.
Показать больше [+] Меньше [-]Solidification/stabilization of soil heavy metals by alkaline industrial wastes: A critical review
2022
Jiang, Qi | He, Yongmei | Wu, Yonglin | Dian, Bo | Zhang, Jilai | Li, Tianguo | Jiang, Ming
Solidification/stabilization technology is one of the most desirable technologies for the remediation of heavy metal contaminated soils due to its convenience and effectiveness. The annual production of alkaline industrial wastes in China is in the hundreds of millions of tons. Alkaline industrial wastes have the potential to replace conventional stabilizers because of their cost effectiveness and performance in stabilizing heavy metals in soils. This paper systematically summarizes the use of four alkaline industrial wastes (soda residue, steel slag, carbide slag, and red mud) for the solidification/stabilization of heavy metal contaminated soils and provides a comprehensive analysis of the three mechanisms of action (hydration, precipitation, and adsorption) and factors that influence the process. In addition, the environmental risks associated with the use of alkaline industrial wastes are highlighted. We found that soda residues, steel slag and carbide slag are appropriate for solidification/stabilization of Pb, Cd, Zn and Cu, while red mud is a potential passivation agent for the stabilization of As in soils. However, implementation of remediation methods using alkaline industrial wastes has been limited because the long-term effectiveness, synergistic effects, and usage in soils containing multiple heavy metals have not been thoroughly studied. This review provides the latest knowledge on the mechanisms, risks, and challenges of using alkaline industrial wastes for solidification/stabilization of heavy metal contaminated soils.
Показать больше [+] Меньше [-]Do industrial parks generate intra-heat island effects in cities? New evidence, quantitative methods, and contributing factors from a spatiotemporal analysis of top steel plants in China
2022
Meng, Qingyan | Hu, Die | Zhang, Ying | Chen, Xu | Zhang, Linlin | Wang, Zian
Industrial parks emit large amounts of anthropogenic heat and aggravate the urban heat island effect, which has become a severe environmental problem worldwide. Few studies explored if the warming effect generated by concentrated industrial facilities (i.e., steel plants in this study) produces an intra-heat island effect in urban built-up areas. Sufficient evidence of an industrial heat island (IHI) effect is lacking, and new quantitative methods are urgently needed to address these issues. Therefore, we proposed a new scheme to quantify the warming effect of large, heat-emitting urban objects versus complex surroundings, and the IHI effect was accordingly defined at a finer scale. This study separated the industrial park from other artificial lands and comprehensively estimated the IHI effects' spatiotemporal variation. The IHI intensities were measured based on varied natural and urbanized references, which provided new evidence for the existence of the IHI effect over space and seasons. The land surface temperature (LST) profiles delineated the downward trend in LST variation from inside to surroundings in the IHI cases on both spatial and temporal scales. The time-series analysis revealed that the IHI effects demonstrated more significant disparities regarding the LSTs between the industrial parks and their surrounding backgrounds during warm seasons than in cold seasons. And a more severe IHI effect was observed in spring and summer, and the weakest IHI intensity occurred in winter. Moreover, the IHI intensity is positively associated to the anthropogenic heat, indicating that the industrial activities contribute to the increased LSTs of the industrial park to a great extent. The rationale of the IHI effect can broaden insight for understanding how urban industrial heat sources influence the regional thermal environment, especially at a finer scale.
Показать больше [+] Меньше [-]Integrated analysis of source-specific risks for PM2.5-bound metals in urban, suburban, rural, and industrial areas
2021
Xu, Jinyou | Chi, Kai-Hsien | Wu, Chih-Da | Lin, Sheng-Lun | Hsu, Wen-Chang | Tseng, Chun-Chieh | Chen, Mu-Jean | Chen, Yu-Cheng
The levels and characteristics of atmospheric metals vary in time and location, can result in various health impacts, which increases the challenge of air quality management. We aimed to investigate PM₂.₅-bound metals in multiple locations and propose a methodology for comparing metal elements across study regions and prioritizing source contributions through integrated health risk assessments. PM₂.₅-bound metals were collected in the urban, suburban, rural, and industrial regions of Taiwan between 2016 and 2018. We incorporated the positive matrix factorization (PMF) with health risk assessments (considering estimates of the margin of exposure (MOE) and excess cancer risk (ECR)) to prioritize sources for control. We found that the concentrations of Fe, Zn, V, Cu, and Mn (industry-related metals) were higher at the industrial site (Kaohsiung) and Ba, Cr, Ni, Mo, and Co (traffic-related metals) were higher at the urban site (Taipei). The rural site (Hualian) had good air quality, with low PM₂.₅ and metal concentrations. Most metal concentrations were higher during the cold season for all study sites, except for the rural. Ambient concentrations of Mn, Cr, and Pb obtained from all study sites presents a higher health risk of concern. In Kaohsiung, south Taiwan, PM₂.₅-bound metals from the iron ore and steel factory is suggested as the first target for control based on the calculated health risks (MOE < 1 and ECR > 10⁻⁶). Overall, we proposed an integrated strategy for initiating the source management prioritization of PM₂.₅-bound metals, which can aid an effort for policymaking.
Показать больше [+] Меньше [-]Polycyclic aromatic compounds in the Canadian Environment: Aquatic and terrestrial environments
2021
Marvin, Christopher H. | Berthiaume, Alicia | Burniston, Deborah A. | Chibwe, Leah | Dove, Alice | Evans, Marlene | Hewitt, L Mark | Hodson, Peter V. | Muir, Derek C.G. | Parrott, Joanne | Thomas, Philippe J. | Tomy, Gregg T.
Polycyclic aromatic compounds (PACs) are ubiquitous across environmental media in Canada, including surface water, soil, sediment and snowpack. Information is presented according to pan-Canadian sources, and key geographical areas including the Great Lakes, the Alberta Oil Sands Region (AOSR) and the Canadian Arctic. Significant PAC releases result from exploitation of fossil fuels containing naturally-derived PACs, with anthropogenic sources related to production, upgrading and transport which also release alkylated PACs. Continued expansion of the oil and gas industry indicates contamination by PACs may increase. Monitoring networks should be expanded, and include petrogenic PACs in their analytical schema, particularly near fuel transportation routes. National-scale roll-ups of emission budgets may not expose important details for localized areas, and on local scales emissions can be substantial without significantly contributing to total Canadian emissions. Burning organic matter produces mainly parent or pyrogenic PACs, with forest fires and coal combustion to produce iron and steel being major sources of pyrogenic PACs in Canada. Another major source is the use of carbon electrodes at aluminum smelters in British Columbia and Quebec. Temporal trends in PAC levels across the Great Lakes basin have remained relatively consistent over the past four decades. Management actions to reduce PAC loadings have been countered by increased urbanization, vehicular emissions and areas of impervious surfaces. Major cities within the Great Lakes watershed act as diffuse sources of PACs, and result in coronas of contamination emanating from urban centres, highlighting the need for non-point source controls to reduce loadings.
Показать больше [+] Меньше [-]New insights into particle-bound trace elements in surface snow, Eastern Tien Shan, China
2020
Huang, Ju | Wu, Guangjian | Zhang, Xuelei | Zhang, Chenglong
Trace elements (TEs) in the insoluble particles of surface snow are less affected by melting processes and can be used as environmental proxies to reveal natural and anthropogenic emissions. Here the first comprehensive study of the 16 TEs (Al, As, Ba, Bi, Cr, Cu, Fe, Mn, Ni, Pb, Sn, Sr, Ti, U, V, and Zn) in insoluble particles (>0.45 μm) from surface snow samples collected at Urumqi Glacier No. 1 (UG1), Eastern Tien Shan, China, from February 2008 to January 2010 were presented. Results show that concentrations of most insoluble particulate TEs (TEs ᵢₙₛₒₗ) in the snow were higher in summer while lower in winter, due to the increasing particle inputs and melting processes. The abundances of As, Cr, Cu, Ni, Pb, and Zn in some samples were higher than those in surrounding urban soils, which might due to these TEs have further anthropogenic input beyond the already contaminated re-suspended urban soil particles and TEs were mainly enriched in particles with small grain size. Based on enrichment factor (EF) and principal component analysis (PCA), our results suggest that eight TEs (Al, Fe, Ti, Ba, Mn, Sr, U, and V) mainly came from mineral dust, while the remaining eight TEs (As, Bi, Cr, Cu, Ni, Pb, Sn, and Zn) were affected by coal combustion, mining and smelting of non-ferrous metals, traffic emissions, and the steel industry. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model suggests that pollutants might originate from Xinjiang province, Kazakhstan, and Kyrgyzstan. Moreover, UG1 received more significant inputs of particle-bound pollutants in summer than in winter due to the stronger convection and the prevailing valley wind that transports pollutants from the city of Urumqi.
Показать больше [+] Меньше [-]Surface coatings select their micro and macrofouling communities differently on steel
2019
Agostini, Vanessa Ochi | Macedo, Alexandre José | Muxagata, Erik | Pinho, Grasiela Lopes Leães
Previous studies have shown the effect of surface coatings on biofouling; however, they did not take into account the interaction of the micro and macrofouling communities, the effect of substrate orientation and the zooplankton-zoobenthic coupling together. Therefore, the aim of this study was to evaluate the effect of Zn- and Cu₂O-based coatings on micro and macrofouling on steel surfaces, while also observing the role of substrate orientation and zooplankton supply. An experiment was carried out in the Patos Lagoon Estuary in southern Brazil for three months between spring and summer, where ASTM-36 steel plates represented different coatings (Zn- and/or Cu₂O-based) and orientations (vertical and horizontal). To assess the zooplankton supply, sampling was carried out weekly using a 200 μm plankton net. Zn-based coating positively affected microfouling density compared to uncoated surfaces. The same pattern was observed with macrofouling, associated with vagile fauna preference, which represented 70% of the settled macrofoulers. Cu₂O-based antifouling painted surfaces showed the highest microfouling density inhibition, while Zn + Cu₂O-based coating did not affect the bacteria adhesion but showed lower density compared to Zn-based coating alone. The coatings combination showed the highest invertebrate inhibition. In this way, the macrofouling community was more sensitive than microfouling was to the antifouling coatings tested. The substrate orientation only affected macrofouling, horizontal surfaces being more attractive than vertical. Meroplankton, tychoplankton and holoplankton were recorded on the surfaces, although their representation in plankton was not proportional to the recruits recorded on the substrates. This was probably due to fast dispersion, the interactions of other factors and/or ecological succession stage. Surface coating, substrate orientation, and zooplankton supply interacted with the biofouling process on steel in different ways depending on the organism evaluated. Therefore, copper oxide- and zinc-based coatings were not suitable as coatings to avoid the total biofouling establishment.
Показать больше [+] Меньше [-]Spatial distribution and exposure risks of ambient chlorinated polycyclic aromatic hydrocarbons in Tokyo Bay area and network approach to source impacts
2018
Ohura, Takeshi | Horii, Yuichi | Yamashita, Nobuyoshi
Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) receive increasing attention as hazardous pollutants in terms of the high environmental persistence and toxicities. Ambient concentrations of 24 ClPAHs and 24 PAHs were investigated at 14 sites in the Tokyo Bay area of Japan. Twelve of 18 ClPAH species were detected in air samples, in spite of small sampling volumes. Mean concentrations of total PAHs in gas and particle phases were 5400 and 1400 pg/m³, and mean concentrations of total ClPAHs in gas and particle phases were 40 and 14 pg/m³, respectively. The spatial distributions of both total ClPAH and PAH concentrations indicated heavy pollution at sites in industrial activity areas. Principal component analysis suggested that the dominant sources of gaseous and particulate ClPAHs differed substantially from each other. In particular, gaseous ClPAHs could be produced by specific sources different from those of particulate ClPAHs. However, the dominant sources of particulate ClPAHs could be the same as those of particulate PAHs, including industrial activities such as steel and gas-production plants and natural gas-fired power plants. The influences of spatial relationships among sampling sites were represented using a network analysis. The constructed network showed that ambient ClPAHs and PAHs were dominated by local rather than regional pollution, because there were weaker relationships among nearby sites. Finally, exposure risks for ClPAHs were dominated by 7-chlorobenz[a]anthracene, followed by 9-chlorophenanthrene and 6-chlorobenzo[a]pyrene, and total risk was ∼1/200 that of PAHs.
Показать больше [+] Меньше [-]Magnetite fine particle and nanoparticle environmental contamination from industrial uses of coal
2018
Sutto, Thomas E.
Recently it has been shown that there are two types of magnetite particles in the human brain, some, which occur naturally and are jagged in appearance, and others that arise from industrial sources, such as coal fired power plants, and are spherical. In order to confirm the latter, the magnetic component of coal ash is first purified and characterized by XRD, showing that it is magnetite with an average particle size of 211 nm. Studies confirm the coal ash magnetic behavior, and that the magnetite is not bound to the other components of coal ash but exist as an isolatable component. SEM studies confirm that in the process of burning coal at very high temperatures for industrial uses, the magnetite formed is spherically shaped, as recent studies of brain tissues of highly exposed urban residents have found. As such, the use of coal for industrial applications such as coking in the production of steel and in power plants is indicated to be a major source of the spherical magnetic combustion-associated magnetite fine particle and nanoparticle environmental pollution. The capacity of these magnetic particles to penetrate and damage the blood-brain-barrier and the early development of Alzheimer's disease hallmarks in exposed populations calls for detail analysis of magnetic fine and nanoparticle distribution across the world.Summation: Industrial coal usage produces spherical magnetic particles and nanoparticles, identical to those associated with neurological disorders.
Показать больше [+] Меньше [-]Ambient PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in Changhua County, central Taiwan: Seasonal variation, source apportionment and cancer risk assessment
2016
Chen, Yu-Cheng | Chiang, Hung-Che | Xu, Jinyou | Yang, Tzu-Ting | Lin, Tzu-Yu | Chen, Mu-Jean | Chen, Nai-Tzu | Wu, Yuh-Shen
This study investigates PM2.5-bound PAHs for rural sites (Dacheng and Fangyuan) positioned close to heavy air-polluting industries in Changhua County, central Taiwan. A total of 113 PM2.5 samples with 22 PAHs collected from 2014 to 2015 were analyzed, and Positive Matrix Factorization (PMF) and diagnostic ratios of PAHs were applied to quantify potential PAH sources. The influences of local and regional sources were also explored using the conditional probability function (CPF) and potential source contribution function (PSCF) with PMF-modeled results, respectively. Annual mean concentrations of total PAHs were 2.91 ± 1.34 and 3.04 ± 1.40 ng/m3 for Dacheng and Fangyuan, respectively, and their corresponding BaPeq were measured at 0.534 ± 0.255 and 0.563 ± 0.273 ng/m3 in concentration. Seasonal variations with higher PAHs found for the winter than for the spring and summer were observed for both sites. The lifetime excess cancer risk (ECR) from inhalation exposure to PAHs was recorded as 4.7 × 10−5 overall. Potential sources of PM2.5-bound PAHs include unburned petroleum and traffic emissions (42%), steel industry and coal combustion (31%), and petroleum and oil burning (27%), and unburned petroleum and traffic emission could contribute the highest ECR (2.4 × 10−5). The CPF results show that directional apportionment patterns were consistent with the actual locations of local PAH sources. The PSCF results indicate that mainly northeastern regions of China have contributed elevated PM2.5-bound PAHs from long-range transports.
Показать больше [+] Меньше [-]