Diuron Sorption, Desorption and Degradation in Anthropogenic Soils Compared to Sandy Soil

ABSTRACT: The aim of this study was to evaluate diuron sorption, desorption and degradation in two anthropogenic soils (Terra Preta de Índio - TPI) in contrast to a sandy soil (Quartzarenic Neosol - NQo). Sorption-desorption studies were performed by the batch equilibrium method and biodegradation in biometric bottles using radiolabeled diuron in 14C. Freundlich coefficient (Kf) values ranged from 13.50 to 50.41 µmol(1-1/n) L1/n kg-1 in TPI-2 and TPI-1, respectively, indicating very high diuron sorption in anthropogenic soils, following the order: TPI-1 ≥ TPI-2 > NQo (99.10, 98.95 and 60.8%, respectively). Diuron desorption was very low in anthropogenic soils, ranging from 1.36 (TPI-1) to 1.70% (TPI-2), and 24% to NQo. Accumulated diuron mineralization to 14C-CO2 was