title: Removal of low concentrations of phenanthrene, fluoranthene and pyrene from urban wastewater by membrane bioreactors technology.
abstract: The fate and removal of phenanthrene (Phen), fluoranthene (F) and pyrene (Py) in urban wastewater treatment by membrane bioreactor (MBR) with low influent polycyclic aromatic hydrocarbons (PAHs) concentration were studied. A full experimental ultrafiltration MBR with a pre-denitrification configuration and capacity to treat 20 m(3)/d was employed. The system was operated with real urban wastewater, to which a concentration of PAHs was added. A constant purge was achieved in order to obtain 12 d of sludge retention time and the hydraulic retention time was 34 h. Concentration of PAHs was determined by Gas Chromatography and Mass Spectrometry with Twister, and mass balance on the MBR system were calculated. Data were supplemented by respirometric analyses, isolation of PAHs degrading microorganisms and bench-scale experiments. All effluent samples presented concentrations of PAHs, with removal levels of 91% and 92% for F and Py respectively, while for Phen performance did not surpass 82%. In spite of the high hydrophobicity of the tested compounds, their accumulation in the biomass was scarce and the sludge presented a low PAH concentration. The experiments reveal that PAHs removal is mainly due to air stripping, with biodegradation and adsorption making an insignificant contribution.
authors.affiliation: Technologies for Water Management and Treatment Research Group, Institute of Water Research and Department of Civil Engineering, University of Granada, Granada, Spain.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: González-Pérez
authors.forename: Gloria
authors.initials: G
authors.lastname: Garralón
authors.forename: Fidel
authors.initials: F
authors.lastname: Plaza
authors.forename: Jorge I
authors.initials: JI
authors.lastname: Pérez
authors.forename: Begoña
authors.initials: B
authors.lastname: Moreno
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Gómez
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D019149:Bioreactors; D005449:Fluorenes / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D010616:Phenanthrenes / Q000378:metabolism*; D011721:Pyrenes / Q000378:metabolism*; D013030:Spain; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis* / Q000382:microbiology; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D005449:Fluorenes; D010616:Phenanthrenes; D011721:Pyrenes; D062065:Wastewater; D014874:Water Pollutants, Chemical; C007738:fluoranthene; C031181:phenanthrene; C030984:pyrene