Sorption of sulfadiazine on Brazilian soils

[Display omitted] ► The sorption of sulfadiazine (SDZ) was studied in four tropical soil–water systems. ► The low values of the KF indicate that SDZ is highly mobile in the evaluated soils. ► The desorption values were higher than those obtained for adsorption of SDZ. ► A small positive hysteresis was observed with all soils under study. ► The main mechanism of the sorption of SDZ is partitioning to organic matter. Antimicrobials, among them sulfonamides are widely used in veterinary medicine and can contaminate the environment. The degree to which antimicrobials adsorb onto soil particles varies widely, as does the mobility of these drugs. Sulfadiazine (SDZ) was used to study the adsorption–desorption in Brazilian soil–water systems, using batch equilibrium experiments. Sorption of SDZ was carried out using four types of soils. Adsorption and desorption data were well fitted with Freundlich isotherms in log form (r>0.999) and (0.984