Combined UV-biological degradation of PAHs.
The UV-photolysis of PAHs was tested in silicone oil and tetradecane. In most cases, the degradation of a pollutant provided within a mixture was lower than when provided alone due to competitive effects. With the exception of anthracene, the larger pollutants (4- and 5-rings) were always degraded first, proving that UV-treatment preferentially acts on large PAHs and thereby provides a good complement to microbial degradation. UV-photolysis was also found to be suitable for treatment of soil extract from contaminated soils. The feasibility of UV-biological treatment was demonstrated for the removal of a mixture of phenanthrene and pyrene in silicone oil. UV-irradiation of the silicone oil led to 83% pyrene removal but no phenanthrene photodegradation. Subsequent treatment of the oil in a two-phases partitioning bioreactor (TPPB) system inoculated with Pseudomonas sp. was followed by complete phenanthrene biodegradation but no further pyrene removal. Totally, the combined process allowed 92% removal of the PAH mixture. Further work should focus on characterizing the photoproducts formed and studying the influence of the solvent on the photodegradation process.
Guieysse
Benoit
B
Department of Biotechnology, Lund University, P.O. Box 124, S-221 00 Lund, Sweden. benoit.guieysse@biotek.lu.se
Viklund
Gunilla
G
Toes
Ann-Charlotte
AC
Mattiasson
Bo
B
D000473:Alkanes; D001673:Biodegradation, Environmental; D007700:Kinetics; D010782:Photolysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry / Q000378:metabolism*; D011549:Pseudomonas / Q000378:metabolism*; D012827:Silicone Oils; D012987:Soil / Q000032:analysis; D014466:Ultraviolet Rays
D000473:Alkanes; D011084:Polycyclic Aromatic Hydrocarbons; D012827:Silicone Oils; D012987:Soil; C024713:n-tetradecane