U(VI) biosorption by Azolla imbircata dry power from solution

Azolla imbircata dry powder (Ai-dp) was prepared by collecting wild Azolla imbircata, drying and grinding. SEM, FTIR and XPS have been used to characterize it. Batch biosorption experiments studied pH, contact time, initial U(VI) concentration, adsorbent dosage and temperature effects on U(VI) biosorption. These results indicated that the maximum biosorption capacity was 4.55 mg L-1 under conditions of 303 K, pH 2.0, initial U(VI) concentration 15 mg L-1 and adsorbent dosage 3.75 g L-1. The biosorption process fit pseudo-second-order kinetics and Langmuir isotherm, it showed the adsorption process was monolayer chemisorption. The thermodynamic fitting results showed the adsorption process was spontaneous and exothermic.