title: Characterization and biodegradation of polycyclic aromatic hydrocarbons in radioactive wastewater.
abstract: PAH degrading Pseudomonad and Alcaligenes species were isolated from landfill soil and mine drainage in South Africa. The isolated organisms were mildly radiation tolerant and were able to degrade PAHs in simulated nuclear wastewater. The radiation in the simulated wastewater, at 0.677 Bq/μL, was compatible to measured values in wastewater from a local radioisotope manufacturing facility, and was enough to inhibit metabolic activity of known PAH degraders from soil such as Pseudomonas putida GMP-1. The organic constituents in the original radioactive waste stream consisted of the full range of PAHs except fluoranthene. Among the observed PAHs in the nuclear wastewater from the radioisotope manufacturing facility, acenaphthene and chrysene predominated--measured at 25.1 and 14.2mg/L, respectively. Up to sixteen U.S.EPA priority PAHs were detected at levels higher than allowable limits in drinking water. The biodegradation of the PAHs was limited by the solubility of the compounds. This contributed to the observed faster degradation rates in low molecular weight (LMW) compounds than in high molecular weight compounds.
authors.affiliation: Water Utilisation Division, Department of Chemical Engineering, University of Pretoria, Pretoria 0002, South Africa.
authors.forename: Phumza V
authors.initials: PV
authors.lastname: Tikilili
authors.forename: Evans M
authors.initials: EM
authors.lastname: Nkhalambayausi-Chirwa
mesh_terms: D001673:Biodegradation, Environmental; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003470:Culture Media / Q000737:chemistry; D004247:DNA / Q000187:drug effects / Q000528:radiation effects; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D008970:Molecular Weight; D010802:Phylogeny; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D016958:Pseudomonas putida / Q000378:metabolism; D011850:Radioactive Waste / Q000032:analysis*; D012989:Soil Pollutants; D014873:Water Pollutants / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D003470:Culture Media; D011084:Polycyclic Aromatic Hydrocarbons; D011850:Radioactive Waste; D012989:Soil Pollutants; D014873:Water Pollutants; D014874:Water Pollutants, Chemical; D004247:DNA