Sorption and mobility of thiabendazole in a Brazilian Oxisol

Abstract

Thiabendazole is a benzimidazole class drug that is widely used due to its vermifugal and fungicidal properties. The present study investigates the behaviour of TBZ in the A and B horizons of a Red-Yellow Latosol typical of southern Minas Gerais State, Brazil. Adsorption and desorption assays were performed under different pH conditions (3.0, 4.2-5.1, and 8.5) and a leaching study was conducted using soil columns. The results demonstrated that the behaviour of TBZ in the soil was influenced by the pH, soil organic matter and clay content. The Freundlich constants indicated that the adsorption capacities for horizons A and B were high (50-149 mg1-1/n.L1/n.kg-1) and low (0-24 mg1-1/n.L1/n.kg-1), respectively. The leaching study results indicated that for both horizons, TBZ presented higher sorption in the initial fractions of the column (0-2 cm), and that the B horizon had a lower adsorption capacity, compared to the A horizon.