小球藻对U(VI)的生物吸附特性

The Character of U(VI) Biosorption by Chlorella pyrenoidosa

摘要:

试验研究了小球藻吸附U(VI)的过程, 探讨了吸附机理、吸附热力学和动力学。考查了pH值、时间、U(VI)的起始浓度和温度等对吸附的影响。研究表明, pH值对小球藻的吸附效果影响较大, 小球藻吸附U(VI)的最佳pH值为6, 最大吸附量为2.7 mg/g, 吸附在5 min内基本达到平衡。小球藻对U(VI)的吸附量与其浓度的正相关; 温度在20℃~30℃时, 对铀的吸附影响不大。实验结果还表明, 吸附过程符合准二级动力学方程, 其相关系数达0.99, 该吸附为多种反应同时作用的复杂过程。U(VI)在小球藻上的吸附行为可以很好地用Langmuir等温方程来描述。

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.