酵母菌吸附Hg^(2+)的动力学及吸附平衡研究

Study on the Adsorption Kinetics and Equilibrium of Yeast to Hg^(2+)

[目的]为酵母菌在治理Hg污染中的应用提供技术参考。[方法]以实验室驯化培养的酵母菌为供试菌株,通过等温吸附试验和吸附动力学试验研究了酵母菌对Hg2+的吸附特性。[结果]酵母菌对Hg2+的吸附是一个动态过程并且进行得很快。该吸附过程可分为2个阶段,第1阶段为快速吸附阶段,该阶段持续10min左右;第2阶段为吸附平衡阶段。用准二级动力学方程模拟酵母菌对Hg2+的吸附过程的可决系数达0.9999。利用拟合出的直线方程可以计算出试验条件下酵母菌对Hg2+的平衡吸附量和吸附平衡常数分别为6.238mg/g和3.021g/(mg.min)。与Freundlich方程相比,Langmuir方程对试验结果的拟合效果更佳。在试验条件下,酵母菌对Hg2+的最大吸附量为9.29mg/L。[结论]该研究为重金属污染的生物防治提供了理论依据。

[ Objective ] The purpose was to provide technical reference for the application of yeast in controlling Hg pollution. [ Method ] With the yeasts acclimatized and cultured in laboratory as tested strains, the adsorption characteristics of yeast to Hg^2＋ were studied through isothermal adsorption experiment and adsorption kinetics experiment. [ Result ] The adsorption of yeast to Hg^2＋ was a very fast dynamic process. This adsorption process could be divided into 2 stages. The 1st stage was fast adsorption stage whose duration was about 10 min and the 2nd stage was adsorption equilibrimn stage. The determination coefficient of modeling the adsorption process of yeast to Hg^2＋. with quasi-second-order kinetic equation was up to 0. 999 9. By using the fitted linear equation, the equilibrium adsorption capacity and adsorption equilibrium constant of yeast to Hg^2＋ under experimental condition were worked out as 6. 238 mg/g and 3. 021 g/（mg · min） resp. Compared with Freundlich equation, the fitting effect of Langmuir equation on experimental results was better. Under experimental condition, the maximum adsorption capacity of yeast to Hg^2＋ was 9.29 mg/L. [ Conclusion ] This study supplied theoretical reference for the biological control of heavy metal pollution.