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U.S. Department of Energy
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Physico-chemical treatments for enhancement of microbial metabolism of xenobiotics

Thesis/Dissertation ·
OSTI ID:5153382

Many xenobiotic chemicals resists biodegradation, but their recalcitrant bonds are sensitive to photolysis. Although photolytic treatment to complete degradation would be too costly, the stimulatory effect of a brief photolysis on subsequent biodegradation of the model pollutants 2,4-dichlorophenol, 2,4,5-trichlorophenol, benzo(a)pyrene, 2,2{prime}, 4,4{prime}, 5,5{prime}-hexachlorobiphenyl, 1,2,4-trichlorobenzene and paranitrotoluene was evaluated in the first part of this study. Hydrogen peroxide was added in some cases as an oxidant to decrease photolysis time. Using {sup 14}C-labeled model compounds, intact and photolyzed solutions were incubated in soil and sewage sludge test systems. Biodegradation was followed by measuring {sup 14}CO{sub 2} evolution and by periodic determinations of solvent-extractable and bound residues, allowing quantitative recovery of applied radiocarbon in most cases. Photolytic treatment greatly increased {sup 14}CO{sub 2} evolution and bound residues resulting in large decreases of solvent-extractable activity. The second part of this study developed a non-destructive method for differentiating these tow possibilities. Two n-alkanes, octadecane (C{sub 18}) and hexatriacontane (C{sub 36}), the latter molecule being essentially recalcitrant in the environment, were packaged into liposomes. Uptake and metabolism rates of packaged versus unpackaged substrates were then compared.

Research Organization:
Rutgers--the State Univ., New Brunswick, NJ (USA)
OSTI ID:
5153382
Country of Publication:
United States
Language:
English