Adsorption of Prometryn in 3 Types of Soil and the Changes of Their Chemical Characteristic Groups

In order to understand the adsorption-desorption process of prometryn in soil and explore its migration, transformation and bioavailability in soil. In this study, batch balance method and Fourier infrared spectroscopy were used to study the adsorption kinetic characteristics of paddy soil, krasnozem and zheltozem and the changes of main groups during the adsorption process. The results showed that the adsorption kinetics of prometryn in the 3 soils tested underwent 3 stages of fast(between 180 min), slow(after 180 min) and equilibrium(720 min) adsorption. The quasi-second-order kinetic equation was consistent with the adsorption kinetics of prometryn in the soil(R² > 0.94). Infrared spectra of the 3 soils all showed characteristic absorption peaks of infrared spectra, such as 3621, 1645 cm⁻¹ and 1028 cm⁻¹, belonging to the Montmorillonite pattern. In the early stage of adsorption(20 min), prometryn was adsorbed on the soil surface, and soil clay minerals and organic matter made positive contributions to the adsorption process. Compared with other intermolecular forces, hydrogen bonds play a dominant role in the whole adsorption process. Hydroxyl functional groups play an important role in the process of adsorption.