title: Screening Nonionic Surfactants for Enhanced Biodegradation of Polycyclic Aromatic Hydrocarbons Remaining in Soil After Conventional Biological Treatment.
abstract: A total of five nonionic surfactants (Brij 30, Span 20, Ecosurf EH-3, polyoxyethylene sorbitol hexaoleate, and R-95 rhamnolipid) were evaluated for their ability to enhance PAH desorption and biodegradation in contaminated soil after treatment in an aerobic bioreactor. Surfactant doses corresponded to aqueous-phase concentrations below the critical micelle concentration in the soil-slurry system. The effect of surfactant amendment on soil (geno)toxicity was also evaluated for Brij 30, Span 20, and POESH using the DT40 B-lymphocyte cell line and two of its DNA-repair-deficient mutants. Compared to the results from no-surfactant controls, incubation of the bioreactor-treated soil with all surfactants increased PAH desorption, and all except R-95 substantially increased PAH biodegradation. POESH had the greatest effect, removing 50% of total measured PAHs. Brij 30, Span 20, and POESH were particularly effective at enhancing biodegradation of four- and five-ring PAHs, including five of the seven carcinogenic PAHs, with removals up to 80%. Surfactant amendment also significantly enhanced the removal of alkyl-PAHs. Most treatments significantly increased soil toxicity. Only the no-surfactant control and Brij 30 at the optimum dose significantly decreased soil genotoxicity, as evaluated with either mutant cell line. Overall, these findings have implications for the feasibility of bioremediation to achieve cleanup levels for PAHs in soil.
authors.affiliation: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States.
authors.forename: Alden C
authors.initials: AC
authors.lastname: Adrion
authors.affiliation: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Nakamura
authors.affiliation: Department of Biological Sciences, North Carolina State University , Raleigh, North Carolina 27695, United States.
authors.forename: Damian
authors.initials: D
authors.lastname: Shea
authors.affiliation: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Aitken
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002460:Cell Line; D004260:DNA Repair / Q000187:drug effects / Q000235:genetics; D008823:Micelles; D009657:North Carolina; D000077423:Polidocanol; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000737:chemistry; D012987:Soil; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D013501:Surface-Active Agents / Q000737:chemistry*; D018675:Toxicity Tests / Q000379:methods; D014867:Water
chemical_list: D008823:Micelles; D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants; D013501:Surface-Active Agents; D014867:Water; D000077423:Polidocanol; D011092:Polyethylene Glycols