Sorption and Desorption of Testosterone at Environmentally Relevant Levels: Effects of Aquatic Conditions and Soil Particle Size Fractions

AbstractSorption and desorption have been found to be critical in the fate and transport of hormones in soils. Previous study indicated that the sorption and desorption properties of soil particles of different size fractions associated with hormones were very different. However, the interaction mechanisms of hormones with these soil particles are still unclear. This study investigated the influence of aquatic conditions [e.g., temperature, hydrogen ion concentration (pH), ionic strength, soil/water ratio, organic matter] on the sorption and desorption of soil particles of three size fractions [i.e., sand (0.425–0.075 mm), silt (0.045–0.002 mm), and clay (0.6–2  μm)] associated with testosterone at environmentally relevant concentrations (i.e., 20–150  ng/L) in batch reactors. The results indicate that lower temperature will facilitate sorption but hinder desorption of testosterone onto/from all of the soil particles. Lower pH and higher organic matter content will favor the sorption of testosterone onto ...