title: Impact of non-ideal sorption on low-concentration tailing behavior for atrazine transport in two natural porous media.
abstract: The impact of non-ideal sorption on atrazine transport was investigated for two sandy porous media with 0.38% and 0.03% organic-carbon contents. In contrast to prior investigations, effluent atrazine concentrations were monitored over a range of five orders of magnitude to examine long-term elution behavior. As characterized by batch-experiments, atrazine experienced nonlinear sorption for both media. The results of the column experiments showed that atrazine exhibited extensive elution tailing (delayed approach to relative concentration of zero). This non-ideal transport was more pronounced for the medium with higher organic-carbon content. A mathematical model incorporating nonlinear, rate-limited sorption/desorption described by a continuous-distribution function was used to successfully simulate atrazine transport.
authors.affiliation: Soil, Water and Environmental Science Department, University of Arizona, 429 Shantz Building, Tucson, AZ 85721, USA.
authors.forename: A
authors.initials: A
authors.lastname: Kempf
authors.forename: M L
authors.initials: ML
authors.lastname: Brusseau
mesh_terms: D000327:Adsorption; D001280:Atrazine / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D006540:Herbicides / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D016062:Porosity; D013056:Spectrophotometry, Ultraviolet
chemical_list: D006540:Herbicides; D002244:Carbon; D001280:Atrazine
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