title: Effect of pH and soil structure on transport of sulfonamide antibiotics in agricultural soils.
abstract: We investigated the effect of solution pH and soil structure on transport of sulfonamide antibiotics (sulfamethoxazole, sulfadimethoxine and sulfamethazine) in combination with batch sorption tests and column experiments. Sorption isotherms properly conformed to Freundlich model, and sorption potential of the antibiotics is as follows; sulfadimethoxine > sulfamethoxazole > sulfamethazine. Decreasing pH values led to increased sorption potential of the antibiotics on soil material in pH range of 4.0-8.0. This likely resulted from abundance of neutral and positive-charged sulfonamides species at low pH, which electrostatically bind to sorption sites on soil surface. Due to destruction of macropore channels, lower hydraulic conductivities of mobile zone were estimated in the disturbed soil columns than in the undisturbed soil columns, and eventually led to lower mobility of the antibiotics in disturbed column. The results suggest that knowledge of soil structure and solution condition is required to predict fate and distribution of sulfonamide antibiotics in environmental matrix.
authors.affiliation: Soil Physics Group, Division of Geoscience, University of Bayreuth, 95440 Bayreuth, Germany. Electronic address: jongyol.park@uni-bayreuth.de.
authors.forename: Jong Yol
authors.initials: JY
authors.lastname: Park
authors.affiliation: Soil Physics Group, Division of Geoscience, University of Bayreuth, 95440 Bayreuth, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Huwe
mesh_terms: D000327:Adsorption; D000900:Anti-Bacterial Agents / Q000032:analysis; D004784:Environmental Monitoring; D006863:Hydrogen-Ion Concentration; D056910:Republic of Korea; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D013412:Sulfadimethoxine / Q000032:analysis*; D013418:Sulfamethazine / Q000032:analysis*; D013420:Sulfamethoxazole / Q000032:analysis*
chemical_list: D000900:Anti-Bacterial Agents; D012987:Soil; D012989:Soil Pollutants; D013412:Sulfadimethoxine; D013418:Sulfamethazine; D013420:Sulfamethoxazole
keywords: Breakthrough curves; Non-equilibrium transport; Process modeling; Reactive transport; Sulfonamide antibiotics