title: Adsorption and desorption of triasulfuron by soil.
abstract: The adsorption and desorption of the herbicide triasulfuron [2-(2-chloroethoxy)-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]benzenesulfonamide] by three soils, soil organic matter (H(+) and Ca(2+)-saturated), and an amorphous iron oxide were studied. Adsorption isotherms conformed to the Freundlich equation. It was found that pH is the main factor influencing the adsorption in all of the systems. Indeed, the adsorption on soils was negatively correlated with pH. The highest level of adsorption was measured on soils with low pH and high organic carbon content. Moreover, it was found that humic acid is more effective in the adsorption compared with calcium humate (the pH values of the suspensions being 3.5 and 6, respectively). Experiments on amorphous iron oxide confirmed the pH dependence. Desorption was hysteretic on soils having high organic carbon content.
authors.affiliation: Dipartimento di Scienze Ambientali Agrarie e Biotecnologie Agro-Alimentari, Università di Sassari, Viale Italia 39, 07100 Sassari, Italy. pusino@uniss.it
authors.forename: Alba
authors.initials: A
authors.lastname: Pusino
authors.forename: Maria Giovanna
authors.initials: MG
authors.lastname: Fiori
authors.forename: Ilaria
authors.initials: I
authors.lastname: Braschi
authors.forename: Carlo
authors.initials: C
authors.lastname: Gessa
mesh_terms: D000327:Adsorption; D006540:Herbicides / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D012987:Soil; D013453:Sulfonylurea Compounds / Q000737:chemistry*; D000096926:Benzenesulfonamides
chemical_list: D006540:Herbicides; D012987:Soil; D013453:Sulfonylurea Compounds; C094039:triasulfuron; D000096926:Benzenesulfonamides