Search

In this work, experiments and modeling for the interactions between uranyl ion and GMZ bentonite in the presence of fulvic acid are presented. The results demonstrated that FA is strongly bound to GMZ bentonite, and these molecules have a very large effect on the U(VI) sorption. The results also demonstrated that U(VI) sorption to GMZ bentonite in the presence and absence of sorbed FA can be well predicted by combining SHM and DLM. According to the model calculations, the nature of the interactions between FA with U(VI) at GMZ bentonite surface is mainly surface complex. The first attempt to simulate clay interaction with humus by the SHM model. [ABSTRACT FROM AUTHOR]

In this work, experiments and modeling for the interactions between uranyl ion and TiO2 in the presence of fulvic acid are presented. The results demonstrated that FA is strongly bound to TiO2, and these molecules have a very large effect on the U(VI) sorption, and vice versa. The results also demonstrated that U(VI) sorption to TiO2 in the presence and absence of sorbed FA can be well predicted with the SCD model (surface and complex distribution). According to the model calculations, the nature of the interactions between FA with U(VI) at TiO2 surface is mainly surface complex and electrostatic potential. [ABSTRACT FROM AUTHOR]

Se(IV) sorption on purified Na-kaolinite was investigated under ambient temperature as functions of contact time, pH, ionic strength and Se(IV) concentration using batch techniques. The rate of sorption is relatively rapid and sorption kinetics of Se(IV) can be successfully described by the pseudo-second-order model. The amount of Se(IV) sorbed was moderately dependent on the solution pH but insensitive to ionic strengths. The sorption/desorption isotherms of Se(IV) show that the sorption process is reversible. A double layer model was set up and used to quantitatively interpret the experimental data. Three surface complexes (≡Al)SeO, ≡ AlSeO and ≡AlOHSeO were proposed which satisfactorily fit our data. [ABSTRACT FROM AUTHOR]