title: Photolysis of atrazine and ametryne herbicides in Barbados sugar cane plantation soils and water.
abstract: The photodegradation kinetics of atrazine (2-chloro-6-(ethylamino)-4-isopropylamino-1,3,5-triazine) and ametryne (2-methylthio-4-ethylamino-6-isopropylamino-s-triazine), in fresh and coastal salt water from Barbados, were measured under irradiation with artificial solar and UV254-radiation. The first-order rate constants were greater for ametryne than for atrazine, and the rates were reduced in seawater relative to fresh water, and in soil slurries relative to fresh water. However, rates were accelerated in the presence of iron(III) at pH 3 due to photo-Fenton type processes. This rate enhancement was reduced at ambient pH values (pH 7-7.5) representative of surface water in Barbados. These results have important implications for the relative persistence of these contaminants in aquatic environments in tropical areas.
authors.affiliation: Division of Environmental Engineering, University of Saskatchewan, Saskatoon, Canada.
authors.forename: Dena W
authors.initials: DW
authors.lastname: McMartin
authors.forename: John V
authors.initials: JV
authors.lastname: Headley
authors.forename: Beverley P
authors.initials: BP
authors.lastname: Wood
authors.forename: Jon A
authors.initials: JA
authors.lastname: Gillies
mesh_terms: D001280:Atrazine / Q000737:chemistry* / Q000528:radiation effects; D001460:Barbados; D001673:Biodegradation, Environmental; D002384:Catalysis; D005618:Fresh Water / Q000737:chemistry; D006540:Herbicides / Q000737:chemistry* / Q000528:radiation effects; D006863:Hydrogen-Ion Concentration; D010782:Photolysis; D012623:Seawater / Q000737:chemistry; D012989:Soil Pollutants / Q000378:metabolism*; D014227:Triazines; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000528:radiation effects
chemical_list: D006540:Herbicides; D012989:Soil Pollutants; D014227:Triazines; D014874:Water Pollutants, Chemical; C100057:ametryne; D001280:Atrazine