title: Degradation of PAHs by high frequency ultrasound.
abstract: Polycyclic aromatic hydrocarbons (PAHs) are persistent organic compounds, which have been reported in the literature to efficiently degrade at low (e.g. 20 kHz) and moderate (e.g. 506 kHz) ultrasound frequencies. The present study focuses on degradation of naphthalene, phenanthrene, and pyrene by ultrasound at three different relatively high frequencies (i.e. 582, 862, and 1142 kHz). The experimental results indicate that for all three frequencies and power inputs ≥ 133 W phenanthrene degrades to concentrations lower than our experimental detection limit (<1 μg/L). Phenanthrene degrades significantly faster at 582 kHz than at 862 and 1142 kHz. For all three frequencies, the degradation rates per unit mass are similar for naphthalene and phenanthrene and lower for pyrene. Furthermore, naphthalene degradation requires less energy than phenanthrene, which requires less energy than pyrene under the same conditions. No hexane-extractable metabolites were identified in the solutions.
authors.affiliation: Department of Civil Engineering, Environmental Engineering Laboratory, University of Patras, Patras 26500, Greece. idman@upatras.gr
authors.forename: Ioannis D
authors.initials: ID
authors.lastname: Manariotis
authors.forename: Hrissi K
authors.initials: HK
authors.lastname: Karapanagioti
authors.forename: Constantinos V
authors.initials: CV
authors.lastname: Chrysikopoulos
mesh_terms: D052918:Environmental Restoration and Remediation / Q000295:instrumentation / Q000379:methods*; D019220:High-Energy Shock Waves; D007700:Kinetics; D009281:Naphthalenes / Q000032:analysis / Q000737:chemistry; D010616:Phenanthrenes / Q000032:analysis / Q000737:chemistry; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000737:chemistry*; D011721:Pyrenes / Q000032:analysis / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D009281:Naphthalenes; D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D014874:Water Pollutants, Chemical; C031721:naphthalene; C031181:phenanthrene; C030984:pyrene