Sulfamethazine Transport in Agroforestry and Cropland Soils

摘要: Knowledge of veterinary antibiotic (VA) transport and persistence is critical to understanding environmental risks associated with these potential contaminants. To understand mobility sulfamethazine (SMZ) sorption processes involved during SMZ in soil, batch experiments were conducted column leaching performed repacked soil columns containing silt loam soils collected from cropland (Crop) an agroforestry (AGF) vegetative buffer system. Bromide (Br − ) was applied as a nonreactive tracer characterize the flow water. Radio-labeled ( 14 C) or without 150 mg L −1 manure-derived dissolved organic carbon (DOC), added pulse compounds monitored for 21 d. Sulfamethazine concentration leachate using liquid scintillation counter high performance chromatography analysis confirmed absence degradation product leachate. Breakthrough curves Br constructed each column. breakthrough fitted convection/dispersion based equilibrium model no sorption, whereas multisite chemical nonequilibrium models linear Freundlich components. Results indicated that three-site two reversible sites (one instantaneous one kinetic) irreversible site coupled component (3S2R-Freu-irrev model) best described through efficiencies 0.998, 0.994, 0.991 AGF, AGF + DOC Crop soils, respectively. No difference small between parameters, such coefficient K d ), f nonlinearity parameter N those obtained observed. Data suggested able retain larger quantity than had little effect on leaching. Greater retention by compared suggests buffers may be viable means mitigate VA loss agroecosystems.