Comparative estimate of polycyclic aromatic hydrocarbons in snow cover at the exhaust zone of aluminum manufactures

Polar Record ◽  
2016 ◽  
Vol 52 (6) ◽  
pp. 645-659 ◽  
Author(s):  
Anna Abramova ◽  
Sergei Chernianskii ◽  
Nataly Marchenko ◽  
Elena Terskaya

ABSTRACTContamination of snow cover has been investigated in the Longyearbyen (78°13 N, 15°38 E) and Barentsburg (78°3 N, 14°12 E) areas, which are situated in the southwest part of Spitsbergen (Svalbard archipelago). Snow cover was sampled in two winter seasons, 2012–2013 and 2013–2014, at 54 locations within potentially contaminated areas. Sampling incorporated the whole snow mass and was combined with morphological observations as well as thickness and density measurements. Meltwater and suspended solids were further analysed for a wide range of contaminants including polycyclic aromatic hydrocarbons (PAHs) and macro-ions. Results were contrasted with previous studies measuring the release of contaminants from snow to soil cover. It was shown in keeping with earlier studies that PAH contributions are associated with airborne particulate matter. The results, in contrast to earlier studies further demonstrated that the high concentrations of contaminants in both settlements are attributed to local sources due to combustion and industrial activity.


Author(s):  
D. N. Gabov ◽  
E. V. Yakovleva ◽  
M. I. Vasilevich ◽  
R. S. Vasilevich

The paper deals with the composition of polycyclic aromatic hydrocarbons (PAHs) in snow cover near the city of Vorkuta (Komi Republic, Russia) in the impact zone of the fuel and energy complex. It includes the results on background aero technogenic pollution levels of Vorkuta and its suburbs for subsequent ecological monitoring and on precipitation areas of different PAH fractions within the impact zones of combined heat-and-power plants, the central water boiler plant, and the territory of Vorkuta. “Light” (easily mobile) PAHs are present at almost any test site and attain extreme values in the impact zones of heat-and-power plant 1, heat-and-power plant 2, the central water boiler plant, and the territory of Vorkuta. They are transported at large distances because of high volatility. In addition, light PAHs are transported with air aerosols as they get adsorbed on fine dust particles. “Heavy” PAHs are present on the territory of the city and in the impact zones of the both energy-and-power plants with local pollution extremes from heat-and-power plant 2 at distances of 0.5, 3.0, 11.2 km but are not transported outside 11.2 km. There are interlinks between accumulation of PAHs and other organic and inorganic pollutants. Concerning analyses of PAHs from snow cover, there exist certain territorial groups which allow for understanding pollution sources (fuel and energy complex, auto transport, coal mining). Indicating ratios of PAHs in snow cover of Vorkuta evidence their pyrogenic genesis.


2019 ◽  
Vol 59 (4) ◽  
pp. 483-493 ◽  
Author(s):  
M. P. Tentyukov ◽  
D. N. Gabov ◽  
D. V. Simonenkov ◽  
E. G. Yazikov

When analyzing chemical compositions of snow the high variability of content of polycyclic aromatic hydrocarbons (PAHs) in snow cover between snowfalls is observed. Researchers explain this by concentrating of snow. However, another mechanism of atmospheric contamination of the snow cover surface is possible. It may be a precipitation of fine crystals of PAHs from the atmosphere in the composition of cryohydrates, which can form aerogenic anomalies on the snow surface at formation of hoarfrost. The process starts in the atmosphere during the interaction of finely dispersed crystals of PAHs with cloud supercooled drops. This results in the cryogenic concentration of solid particles of PAHs by way of formation of solid eutectic mixture – cryohydrates, which are a two-phase system consisting of a fine mixture of crystals of solid particles and ice. Evidence of their manifestation is the presence of the Forel hatching on the surface of the facets of the hoarfrost crystals appearing due to the different optical density of alternating zones, which consist of interpenetrating domains of crystallized solid aerosols and ice. At the same time, due to the presence of temperature inversion over the snow cover and its drying effect on the near-snow layer of air, a stable mass transport of water vapor down to the snow cover is formed, which can initiate the flow of fine cryohydrates from the PAHs. Therefore, the growth of atmospheric ice crystals, begun in the surface atmosphere, continues on the snow surface during formation of hoarfrost, thus creating a special nano-relief of snow cover. The paper presents the results of observations of changes in the concentration of individual PAHs in the upper 18 mm layer of snow at accumulation of the surface hoarfrost during a long period between snowfalls. Some micro-morphological features of the forms of skeletal rime micro-crystals are shown, with which an increase in the nano-roughness of the snow surface is associated, as well as the manifestation of the signal of the aerogenic PAH anomaly on the snow surface. Since the conditions for the formation of surface hoarfrost occur more often than for snowfalls, the hoarfrost may be an informative object of testing when detecting hydrocarbon contamination of snow cover during the intervals between snowfalls.


2019 ◽  
Vol 64 (1) ◽  
pp. 55-67
Author(s):  
Vlad Pӑnescu ◽  
◽  
Mihaela Cӑtӑlina Herghelegiu ◽  
Sorin Pop ◽  
Mircea Anton ◽  
...  

2019 ◽  
Author(s):  
Yachu Du ◽  
Kyle Plunkett

We show that polycyclic aromatic hydrocarbon (PAH) chromophores that are linked between two five-membered rings can access planarized structures with reduced optical gaps and redox potentials. Two aceanthrylene chromophores were connected into dimer model systems with the chromophores either projected outward (2,2’-biaceanthrylene) or inward (1,1’-biaceanthrylene) and the optical and electronic properties were compared. Only the planar 2,2’-biaceanthrylene system showed significant reductions of the optical gaps (1 eV) and redox potentials in relation to the aceanthrylene monomer.<br>


2019 ◽  
Author(s):  
Yachu Du ◽  
Kyle Plunkett

We show that polycyclic aromatic hydrocarbon (PAH) chromophores that are linked between two five-membered rings can access planarized structures with reduced optical gaps and redox potentials. Two aceanthrylene chromophores were connected into dimer model systems with the chromophores either projected outward (2,2’-biaceanthrylene) or inward (1,1’-biaceanthrylene) and the optical and electronic properties were compared. Only the planar 2,2’-biaceanthrylene system showed significant reductions of the optical gaps (1 eV) and redox potentials in relation to the aceanthrylene monomer.<br>


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