ABSTRACT
The process of U(VI) biosorption by freshwater algae Chlorella pyrenoidosa and its absorption mechanism, absorption thermodynamics and absorption kinetics were investigated in this paper. The effects of pH, contact time, initial U(VI) concentration and temperature on biosorption were studied respectively. Research result showed that the absorption effect of U(VI) by Chlorella pyrenoidosa was affected by pH value of solution to a great extent, the absorption reached its balance within 5 min with optimal pH value 6 and max absorption quantity 2.7 mg/g. On the other hand, the absorption quantity of U(VI) by Chlorella pyrenoidosa was positively correlated with the initial concentration of U(VI); and the absorption quantity did not fluctuate remarkably when temperature was varied at the range of 20℃ to 30℃. Research result also showed that the process of U(VI) absorption was congruent with the second order kinetic model, and the correlation coefficient was high reaching to 0.99. It was suggested that the U(VI) biosorption by Chlorella pyrenoidosa was a complicated process consisting of many simultaneous reactions and could be described by Languir model quite well.