Abstract:

The adsorption-desorption characteristics of hippuric acid (HA) in soils and iron oxide were investigated to provide the basic data on evaluating the safety in the environment. The characteristics of hippuric acid (HA) adsorption and desorption in the soil, goethite and ferrihydrite were investigated by using the equilibrium method. The Langmuir model was the best isotherm to describe all experimental data of adsorption and desorption, and the average fitting correlation coefficient was 0.992. The maximum adsorption capacity of HA in ferrihydrite and goethite was 434.5 mg/kg and 103.5 mg/kg, 20.89 times and 5.22 times larger than the soil. In which the ferrihydrite was greater than the goethite 4.20 times. The adsorption capacity (lgKf) was in the order ferrihydrite > goethite > soil. The desorption of HA existed hysteresis in the soil, goethite and ferrihydrite. It was concluded that, the adsorption capacity and ability of HA in ferrihydrite were all the highest.