title: Frequency effect on the sonochemical remediation of alachlor.
abstract: The effect of ultrasonic frequency on the sonodegradation of alachlor is described. The rate observed for the destruction of alachlor is approximately 25 times faster at 300 kHz under argon saturation than at 20 kHz under comparable acoustic input energy. The effect of variation of a number of extrinsic parameters such as dissolved gases, radical scavengers and hydroxyl radical promoters is also explored. Argon-saturated solutions display an enhancement in rate by a factor of two compared to either oxygen- or air-saturated solutions upon sonication at 300 kHz. The principal ultrasonic degradation products have been determined in air, argon, and oxygen. The products results primarily from cleavage of the N-methoxymethyl unit when sonication occurs in argon and air. Oxygen addition has been observed when the saturating gas is oxygen. The nature of the active site for reactivity of alachlor is discussed.
authors.affiliation: Department of Chemistry and Biochemistry, Texas Tech University, Box 41061, 79409-1061 Lubbock, TX, USA.
authors.forename: Darcey G
authors.initials: DG
authors.lastname: Wayment
authors.forename: Dominick J
authors.initials: DJ
authors.lastname: Casadonte
mesh_terms: D000081:Acetamides / Q000737:chemistry*; D004785:Environmental Pollutants; D004787:Environmental Pollution / Q000517:prevention & control; D016166:Free Radical Scavengers; D005740:Gases; D006540:Herbicides / Q000737:chemistry*; D006861:Hydrogen Peroxide; D007700:Kinetics; D010100:Oxygen; D012996:Solutions; D013010:Sonication
chemical_list: D000081:Acetamides; D004785:Environmental Pollutants; D016166:Free Radical Scavengers; D005740:Gases; D006540:Herbicides; D012996:Solutions; C000188:alachlor; D006861:Hydrogen Peroxide; D010100:Oxygen