Sorption–desorption hysteresis of uranium(VI) on/from GMZ bentonite

In this study, we examined the sorption and desorption behavior of U(VI) on/from a Chinese bentonite in the solid–liquid system using batch experiments, and the influence of pH, ionic strength and humic acid (HA) on the sorption–desorption hysteresis in the solid–liquid system were quantitatively calculated. It was revealed that the hysteresis was enhanced with increasing pH and increasing ionic strength. HA promoted the sorption, but lower the sorption–desorption hysteresis. Meanwhile, hysteresis in ternary bentonite-HA-U system was found to be higher than that in bentonite-U-HA system, indicating different sorption structures formed because of different addition sequence.