scholarly journals Specificity of accumulation of hydrocarbons in various components of geosystems

2020 ◽  
Vol 169 ◽  
pp. 01013
Author(s):  
Aleksandr Khaustov ◽  
Margarita Redina

The results of the analysis of thermodynamic characteristics of the processes of hydrocarbon amassment in the components of geochemical systems are presented (waters, soils, plants and other substances forming ecosystem). The need to use an ideology and apparatus for calculating thermodynamics is due to the complexity and diversity of mass transfer in interacting media. The material and energy flows of marker compounds, polycyclic aromatic hydrocarbons (PAHs), are analyzed: Naphthalene (Naph), Acenaphthene (Ace), Fluorene (Flourene), Phenanthrene (Phen), Anthracene (An), Fluoranthene (Flu), Pyrene (Py), benzo[a]anthracene (BaA), Chrysene (Chr), Benzo[b]fluoranthene (BbFlu), Benzo[k]fluoranthene (BkFlu), Benzo[a]pyrene (BaP), Benzo[ghi]perylene (Bghi), Dibenzo[a, h]anthracene (DbA), Indeno[1, 2-cd]pyrene (Ip). Estimates are obtained of the intensity of PAH concentration processes in geochemical systems in different states from the point of view of stability, from clearly unstable to metastable. The role of living matter in the formation of stability of geochemical systems is revealed.

Author(s):  
Aleksandr P. Khaustov ◽  
◽  
Margarita M. Redina ◽  

The purpose of the study was to identify patterns of fractionation at geochemical barriers (GCB) of associations of marker compounds - polycyclic aromatic hydrocarbons (PAHs). Based on thermodynamic parameters, the throughput of GCB in geochemical systems (GCS) in relation to organic substances at the molecular level is analyzed. PAHs are very informative indicators of the properties of GCB (up to singular surfaces). The processes of migration and selective penetration through GCB of 15 PAHs from the list of priority pollutants recommended by the US Environmental Protection Agency (widely used in the world EPA list): Naphthalene (Naph), acenaphthene (Ace), Fluorene (Flourene), Phenanthrene (Phen), Anthracene (An), Fluoranthene (Flu), Pyrene (Py), Benzo(a)Anthracene (BaA), Chrysene (Chr), Benzo(b)Fluoranthene (BbFlu), Benzo(k)fluoranthhene (BkFlu), Benzo(a)pyrene (BaP), benzo(ghi)perylene (Bghi), Dibenzo(a, h) anthracene (DbA), Indeno(1,2-cd)pyrene (Ip). Being geochemical markers, these compounds can accumulate on barriers and selectively penetrate through them, making them especially important objects of study. Despite numerous studies, these mechanisms of mass transfer have not been sufficiently studied. The types of GCB have been identified in terms of their permeability to PAHs. It is shown that the functions of GCB in systems are much more significant and consist not only in the separation of systems from the external environment and the regulation of mass transfer. The above models of migration and accumulation are based on quantitative estimates, which makes the results more reasonable in comparison with the “conceptual” representations of the behavior of substances on GCB in most studies. The most important point - the influence of the medium contact time for establishing a stable state (stability by the migration of compounds) on GCB has been demonstrated.


2020 ◽  
Vol 163 ◽  
pp. 06008
Author(s):  
Aleksandr Khaustov ◽  
Margarita Redina ◽  
Inna Nemirovskaya

Material and energy flows in the marginal filters of rivers identified based on the analyses of the environmental fate of polycyclic aromatic hydrocarbons (PAH): Anthracene (An), Phenanthrene (Phen), Naphthalene (Naph), Pyrene (Py), Fluoranthene (Flu), Chrysene (Chr), Benzo[a]pyrene (BaP), Perylene (Pl). Experimental data on the components of the aquatic system of the marginal filter of the Northern Dvina River allow us to consider the processes of phase transitions of PAHs at geochemical barriers (GCB). Based on the principles of thermodynamics, a phenomenological model of migration and the formation of the most persistent PAH associations on the barriers is formed. The predominant possibility of PAH migration on suspended material, including biota, is shown. The probability of PAH accumulation between the most important components of aquatic systems was assessed according to the conditions of their migration activity in various zones of the marginal filter. Active and passive PAHs were determined in terms of their migration and accumulation in the components of aquatic systems. The role of PAHs as a reliable indicator of thermodynamic processes, including the development of technogenesis, is estimated.


1995 ◽  
Vol 45 (2) ◽  
pp. 101-126 ◽  
Author(s):  
Donna R. Davila ◽  
DeAnn P. Davis ◽  
Kerry Campbell ◽  
John C. Cambier ◽  
Letitia A. Zigmond ◽  
...  

1992 ◽  
Vol 47 (12) ◽  
pp. 1764-1774 ◽  
Author(s):  
Karl-Dietrich Gundermann ◽  
Elke Romahn ◽  
Maximilian Zander

9,10-Di(1-naphthyl)phenanthrene (5 a) and 9,10-di(2-naphthyl)phenanthrene (5 b) have been synthesized. It is shown that 5 a and 5b both form two stable rotational (cis/trans) isomers with the naphthalene molecular planes perpendicular to the phenanthrene plane. In the case of 5 a the mixture of the two isomers has been separated in a preparative scale and each isomer characterized by e. g., NMR spectroscopy. Photocyclization of 5a leads to benzo[e]phenanthro[1,2,3,4-ghi]perylene (9) while 5 b yields phenanthro[9,10-i]pentahelicene (14); both hydrocarbons have not been previously described in the literature. The observed selectivities of photocyclization are explained on the basis of the structures and stabilities of the initially formed photoproducts (dihydro structures 15 and 14 a). The role of intramolecular non-radiative singlet-singlet energy transfer (naphthalene → phenanthrene) as competing with photocyclization is discussed in detail.


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