Continuous Ozonation of Polycyclic Aromatic Hydrocarbons in Oil/Water-Emulsions and Biodegradation of Oxidation Products

1999 ◽  
Vol 40 (4-5) ◽  
pp. 107-114 ◽  
Author(s):  
A. Kornmüller ◽  
U. Wiesmann
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Biological Treatment ◽  
Reaction Rate ◽  
Oxidation Products ◽  
Direct Reaction ◽  
Biological Degradation ◽  
Polycyclic Aromatic ◽  
Oil Water ◽  
Treatment Step

The continuous ozonation of polycyclic aromatic hydrocarbons (PAH) was studied in a two stage ozonation system followed by serobic biological degradation. The highly condensed PAH benzo(e)pyrene and benzo(k)fluoranthene were oxidized selectiely in synthetic oil/water-emulsions. The influence of the ozone mass transfer gas-liquid on the reaction rate of benzo(k)fluoranthene was studied for process optimization. The dissolved ozone concentration is influenced by temperature to a higher degree than the reaction rate of PAH. In dependence on pH, PAH oxidation occurs by a direct reaction with ozone inside the oil droplets. Two main ozonation products of benzo(e)pyrene were quantified at different retention times during ozonation and their transformation could be shown in the biological treatment step.

Selective ozonation of polycyclic aromatic hydrocarbons in oil/water-emulsions

1997 ◽  
Vol 35 (4) ◽  
pp. 57-64 ◽  
Author(s):  
Anja Kornmüller ◽  
Michael Cuno ◽  
Udo Wiesmann
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
No Oxidation ◽  
Direct Reaction ◽  
Oxidation Rates ◽  
High Oxidation ◽  
Polycyclic Aromatic ◽  
Influence Of Temperature On ◽  
Oil Water ◽  
High Concentrations

The ozonation of three to five ring condensed polycyclic aromatic hydrocarbons (PAH) was studied in synthetic oil/water-emulsions by batch experiments. PAH can be oxidized selectively in the presence of high concentrations of dodecane as an aliphatic solvent. No oxidation of dodecane, as a representative of mineral oil, could be observed during all experiments - even at pH around 11. At acid to neutral pH high oxidation rates of the PAH were achieved due to a direct reaction with ozone. In the investigated range of 20 to 40°C no influence of temperature on the ozonation of benzo(k)fluoranthene could be found. During competitive ozonation of five PAH, the reactions are completed in the sequence of acenaphthene, pyrene and finally benzo(e)pyrene, benzo(k)fluoranthene and phenanthrene almost at the same time.

Enhancement of polycyclic aromatic hydrocarbons removal during anaerobic treatment of urban sludge

2003 ◽  
Vol 48 (4) ◽  
pp. 53-60 ◽  
Author(s):  
E. Trably ◽  
D. Patureau ◽  
J.P. Delgenes
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Sewage Sludge ◽  
Aromatic Hydrocarbons ◽  
Agricultural Soils ◽  
Biogas Production ◽  
Bacterial Consortium ◽  
Anaerobic Treatment ◽  
Biological Degradation ◽  
Low Concentrations ◽  
Polycyclic Aromatic

Anaerobically stabilized sewage sludge has potential to partially substitute synthetic fertilizers. The main risk with the recycling of urban sludge on agricultural soils is the accumulation of unwanted products, such as trace metals and organic micropollutants. In this context, the polycyclic aromatic hydrocarbons (PAHs) are particularly monitored because of their toxic properties at low concentrations and their high resistance to biological degradation. The aim of the present study was to optimize PAHs removal during anaerobic digestion of contaminated sewage sludge. Thirteen PAHs were monitored in laboratory-scale anaerobic bioreactors under mesophilic (35°C) and thermophilic (55°C) methanogenic conditions. Abiotic losses were statistically significant for the lightest PAHs, such as fluorene, phenanthrene and anthracene. It was shown that PAH removal was due to a specific biological activity. Biological PAHs removal was significantly enhanced by an increase of the temperature from 35°C to 55°C, especially for the heaviest PAHs. Bioaugmentation experiment was also performed by addition of a PAH-adapted bacterial consortium to a non-acclimated reactor. Significant enhancement of PAHs removal was observed. It was finally shown that PAH removal efficiencies and methanogenic performances were closely linked. The rate of biogas production may be used as an indicator of bacterial activity on PAH removal.

scholarly journals Processes of chemical transformations in heavy aromatic hydrocarbons of the Surakhan oil under the action of UV rays

2021 ◽  
Vol 2064 (1) ◽  
pp. 012108
Author(s):  
U J Yolchuyeva ◽  
R A Jafarova ◽  
V M Abbasov ◽  
N I Mursalov ◽  
G A Hajiyeva ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Atmospheric Oxygen ◽  
Oxidation Products ◽  
Chemical Transformations ◽  
Atmospheric Conditions ◽  
Oxidative Reactions ◽  
Polycyclic Aromatic ◽  
Aromatic Components ◽  
Uv Rays

Abstract Photooxidative transformations and mechanisms of oxidative reactions in aromatic groups of hydrocarbons isolated from heavy Surakhan (Azerbaijan) petroleum under atmospheric conditions have been investigated. Polycyclic aromatic hydrocarbons, which are part of the aromatic components of heavy Surakhan petroleum, after irradiation with UV rays for 1÷11 hours in the presence of oxygen undergo chemical transformations: endoperoxides polycyclic aromatic hydrocarbons, quinones, etc. are formed. It was found that oxidation products under atmospheric conditions can be formed as follows: during the oxidation of acenes (naphthalene, anthracene), which are part of the aromatic groups of petroleum components, excited aromatic hydrocarbons (donor) interact with atmospheric oxygen (acceptor) in the triplet state with the transition of the acceptor to excited state with the formation of singlet oxygen 1O2, in this case the donor molecule returns to the ground state. When phenanthrene is photooxidized, quinones are formed (the reaction is irreversible).

scholarly journals Oxidation of PAHs in water solution by ozone combined with ultraviolet radiation

2001 ◽  
Vol 3 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Stanislaw Ledakowicz ◽  
Jacek S. Miller ◽  
Dorota Olejnik
Keyword(s):  
Aqueous Solution ◽  
Aromatic Hydrocarbons ◽  
Reaction Rate ◽  
Water Solution ◽  
Radical Reaction ◽  
Radical Scavenger ◽  
Direct Reaction ◽  
Acidic Solutions ◽  
Polycyclic Aromatic ◽  
Influence Of Ph

The oxidation of three polycyclic aromatic hydrocarbons (PAHs): benzo[a]pyrene (BAP), chrysene (CHR) and fluorene (FLU) in aqueous solution using ozone assisted by UV radiation was investigated. The influence of pH of the reaction mixture, ozone concentration and the presence of a radical scavenger on the reaction rate was determined. The highest rate of PAHs disappearance was achieved in acidic solutions. The radical scavenger-tert-butanol, effectively inhibited the rate of BAP and CHR destruction but had a slight influencein thecaseof FLU. Therateconstants of direct reaction of PAHs with ozonewe recalculate d using our earlier investigations and they were equal to6.8×104;6.9×103and62M-1s-1for BAP, CHR and FLU, respectively. The contributions of direct ozonolysis, photolysis and radical reaction to PAHs oxidation inO3/UVsystem were evaluated.

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