Biodegradation polycyclic aromatic compounds

Selifonov SA, PJ Chapman, SB Akkerman, JE Gurst, JM Bortiatynski, MA Nanny, PG Hatcher (1998) Use of nuclear magnetic resonance to assess fossil fuel biodegradation fate of [l- C]acenaphthene in creosote polycyclic aromatic compound mixtures degraded by bacteria. Appl Environ Microbiol 64 1447-1453. 

The treatment by ozone can be successfully applied for decomposing mineral oils, polycyclic aromatic compounds (PACs), phenols and some pesticides to biodegradable, nontoxic compounds. It should be noted that although ozone decomposes a great number of microorganisms, the soil microflora can be easily remediated after this treatment [52]. The latter can be carried out on- and out of the contaminated area. A number of problems related to the ozonolysis of organic compounds, the PACs degradation products, the effect of ozone on the soil microflora, the laboratory and pilot results, etc., are discussed. 

The PetroClean bioremediation system treats biodegradable contaminants (i.e., gasoline, diesel fuel, aviation fuel, solvents, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), total petroleum hydrocarbons (TPH), and other organic compounds in soils and groundwater. 

This type of substrate-substrate interaction may be especially important for contaminants introduced as mixtures in the environment. One example is the mix of polycyclic aromatic hydrocarbons co-introduced in oil spills or in coal tar wastes. Laboratory observations of the biodegradation of such hydrocarbons show that some of these components can inhibit the removal of other compounds in the mix (Guha et al., 1999). Such results indicate that the rate of a particular chemical s biotransformation may be a function of factors such as the presence of competing substrates interacting with the same enzyme systems. 

Aust, S. D., Shah, M. M., Barr, D. P. Chung, N. (1994). Biodegradation of environmental pollutants by white-rot fungi. In Bioremediation of Chlorinated and Polycyclic Aromatic Hydrocarbon Compounds, ed. R. E. Hinchttetal., pp. 441-5. Boca Raton, FL CRC Press. 

A series of related experiments investigated nonionic surfactant sorption onto soil, mechanisms of nonionic surfactant solubilization of polycyclic aromatic hydrocarbon (PAH) compounds from soil, and microbial mineralization of phenanthrene in soil-aqueous systems with nonionic surfactants. Surfactant solubilization of PAH from soil at equilibrium can be characterized with a physicochemical model by using parameters obtained from independent tests in aqueous and soil-aqueous systems. The microbial degradation of phenanthrene in soil-aqueous systems is inhibited by addition of alkyl ethoxylate, alkylphenyl ethoxylate, or sorbitan- (Tween-) type nonionic surfactants at doses that result in micellar solubilization of phenanthrene from soil. Available data suggest that the inhibitory effect on phenanthrene biodegradation is reversible and not a specific, toxic effect. 

Scientific research confirms that biofuel has a less harmful effect on human health than petroleum fuel. Biofuel emissions have decreased levels of polycyclic aromatic hydrocarbons (PAHs) and nitrited PAH compounds (nPAH), which have been identified as cancer causing compounds. Test results indicate that PAH compounds were reduced by 50-85%. Targeted nPAH compounds were reduced by 90%. Biofuel is nontoxic and biodegradable. In addition, the flash point (the lowest temperature at which it can form an ignitable mix with air) is 300° F, well above petroleum fuel s flashpoint of 125°F. 

Aerobic biodegradation of polycyclic and halogenated aromatic compounds... 

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