title: Retention of pesticides in soil columns modified in situ and ex situ with a cationic surfactant.
abstract: A study of the effect of a clayey soil modified in situ and ex situ with the cationic surfactant octadecyltrimethylammonium bromide (ODTMA), on the retention of linuron, atrazine and metalaxyl was carried out. Leaching of these compounds was studied in columns of a natural clayey soil and the same clayey soil modified by direct injection of the surfactant in situ, and in columns of a natural sandy soil and the same sandy soil modified by intercalation of a barrier of the clayey soil saturated ex situ with the surfactant. Breakthrough curves indicated the total immobilization of linuron in modified soils and a decrease in the leaching kinetics of atrazine and metalaxyl compared to what was obtained in the natural soil. The results indicate the use of the clayey soil modified in situ or ex situ with the surfactant ODTMA could be of interest in the immobilization of pesticides of different hydrophobicities.
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Salamanca, CSIC, Salamanca, Spain.
authors.forename: María Sonia
authors.initials: MS
authors.lastname: Rodríguez-Cruz
authors.forename: Maria Jesús
authors.initials: MJ
authors.lastname: Sánchez-Martín
authors.forename: María Soledad
authors.initials: MS
authors.lastname: Andrades
authors.forename: María
authors.initials: M
authors.lastname: Sánchez-Camazano
mesh_terms: D000327:Adsorption; D000409:Alanine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D000473:Alkanes; D001280:Atrazine / Q000032:analysis / Q000737:chemistry*; D001546:Bentonite; D002412:Cations; D057927:Hydrophobic and Hydrophilic Interactions; D008044:Linuron / Q000032:analysis / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds; D012989:Soil Pollutants / Q000737:chemistry; D013501:Surface-Active Agents; D014876:Water Pollution / Q000517:prevention & control
chemical_list: D000473:Alkanes; D002412:Cations; D010575:Pesticides; D000644:Quaternary Ammonium Compounds; D012989:Soil Pollutants; D013501:Surface-Active Agents; C518260:octadecyltrimethylammonium bromide; D008044:Linuron; D001546:Bentonite; C028175:metalaxyl; D000409:Alanine; D001280:Atrazine