Adsorption-desorption of Atrazine with 9 Agricultural Soils in China

In this work, the characteristics and mechanisms for atrazine adsorption-desorption with 9 types of soils were investigated with batch equilibrium studies, elemental analyses, infrared spectroscopy, and UV‒visible spectroscopy. The atrazine sorption data for the 9 soils showed better fits with the Freundlich model than the Langmuir model, except with Red earth in Jiangxi (REJ) The results showed that the adsorption capacity was positively correlated with the organic matter (OM) content and negatively correlated with cation-exchange capacity (CEC) and pH. UV‒visible spectroscopy showed that dissolved organic matter (DOM) in the soil enhanced atrazine adsorption, but the adsorption on different DOM fractions was quite different. In addition, the infrared spectra revealed differences in the functional groups of soils and these functional groups may drive the adsorption process via hydrogen bonding and coordination with the -NH₂ groups in atrazine.