title: Sonophotocatalytic degradation of alazine and gesaprim commercial herbicides in TiO2 slurry.
abstract: The photocatalytic degradation of alazine and gesaprim commercial herbicides was carried out in aqueous TiO(2) suspensions under UV light (15W, 352 nm). Degradation of these herbicides was also observed by the combined effects of photocatalysis with sonolysis (sonophotocatalysis) using an ultrasound source of 20kHz. Degradation profiles were recorded by measuring the concentration of the active compounds present in the alazine (alachlor and atrazine) and gesaprim (atrazine) by HPLC as a function of irradiation time (sound and/or light). Over 90% of the active component in the gesaprim was abated and those in alazine were completely degraded. The content of total organic carbon and chemical oxygen demand was also monitored. Mineralization of the commercial herbicides was achieved. Over 80% of chemical oxygen demand abatement was attained for both herbicides with sonophotocatalysis at 150 min of irradiation time. The photocatalytic degradation of the herbicides followed a pseudo-first order kinetics and their rate constant was increased by the combined effects of sonolysis.
authors: Posgrado en Ingeniería y Ciencias Aplicadas, FCQeI-CIICAp, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos 62209, México.
authors: Cristina Lizama
authors: CL
authors: Bahena
authors: Susana Silva
authors: SS
authors: Martínez
authors: Daniel Morales
authors: DM
authors: Guzmán
authors: Ma
authors: M
authors: Del Refugio Trejo Hernández
mesh_terms: D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D052918:Environmental Restoration and Remediation; D006540:Herbicides / Q000737:chemistry*; D007700:Kinetics; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry*; D014227:Triazines / Q000737:chemistry*; D014465:Ultrasonics; D014466:Ultraviolet Rays
chemical_list: D006540:Herbicides; D014227:Triazines; C009495:titanium dioxide; D014025:Titanium