title: Adsorption and desorption characteristics of several herbicides on sediment.
abstract: The objective of this study was to clarify the adsorption and desorption characteristics of several herbicides in sediment. Five herbicides, esprocarb, thiobencarb, dimethametryn, pretilachlor, and simetryn were examined in this study. The adsorption ratio on the sediment increased in the following order: pretilachlor < dimethametryn < simetryn < thiobencarb < esprocarb. On the other hand, the adsorption ratio on the sediment without organic matter increased in the following order: thiobencarb < esprocarb < pretilachlor < dimethametryn < simetryn. Furthermore, the amounts of simetryn, dimethametryn, and pretilachlor adsorbed on the sediment without organic matter increased, while those of esprocarb and thiobencarb decreased in comparison to the original sediment. These results strongly suggested that the mineral surface in the sediment was very important as the adsorption site for the herbicide, especially in the case of simetryn, dimethametryn, and pretilachlor. All the adsorption and desorption data fitted well with the Freundlich equation. The hysteresis in the adsorption-desorption phenomena in the sediment was observed for all the herbicides, and it was affected by the organic matter in sediment, especially in the case of dimethametryn and pretilachlor.
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Japan. river_t@rs.noda.tus.ac.jp
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kawakami
authors.forename: Heesoo
authors.initials: H
authors.lastname: Eun
authors.forename: Masumi
authors.initials: M
authors.lastname: Ishizaka
authors.forename: Shozo
authors.initials: S
authors.lastname: Endo
authors.forename: Kenji
authors.initials: K
authors.lastname: Tamura
authors.forename: Teruo
authors.initials: T
authors.lastname: Higashi
mesh_terms: D000042:Absorption; D000327:Adsorption; D019015:Geologic Sediments / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry* / Q000493:pharmacokinetics; D007700:Kinetics; D008903:Minerals / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology; D012987:Soil; D012995:Solubility
chemical_list: D006540:Herbicides; D008903:Minerals; D012987:Soil