摘要
为了探讨灭活面包酵母菌对Pb^(2+)、Cd^(2+)的单、双重金属离子体系(以下简称双离子体系)的吸附效果及影响机制,选择灭活面包酵母菌为吸附剂,对Pb^(2+)、Cd^(2+)的单离子体系和Pb^(2+)-Cd^(2+)双离子体系吸附动力学过程和等温吸附效果进行研究。结果表明,不同离子体系中,在相同初始浓度情况下,面包酵母菌对Pb^(2+)的吸附量总是大于对Cd2+的吸附量。试验条件下,面包酵母菌对Pb^(2+)、Cd^(2+)的单离子体系和Pb^(2+)-Cd^(2+)双离子体系等温吸附符合Langmuir模型,最大吸附量q_(max)分别为0.414 9 mmol/g、0.346 8 mmol/g和0.488 5 mmol/g。SEM/EDS分析表明,Pb^(2+)、Cd^(2+)被吸附到菌体上,造成菌体变形或出现破裂,并使内部物质外泄,这可能是吸附进行一定时间后出现二次吸附过程的主要原因。灭活面包酵母对Pb^(2+)和Cd^(2+)具有良好的吸附效果,对Pb^(2+)-Cd^(2+)双离子体系的吸附,离子间的点位竞争和联合毒性作用是影响体系总体吸附效果的重要因素。
The given paper is to present our study on the biosorption effect and the mechanism of Pb^2＋ and Cd^2 ＋ ions on autoclaved baker＇ s yeast in single and double heavy metal ions systems. Autoclaved baker＇s yeast was chosen as biosorbent, then the kinetic process and isotherm effect were studied in the different ion systems of Pb^2＋ and Cd^2＋ . The experimental results show that the biosorption of Pb^2＋ on baker＇s yeast proves always more effective than that of Cd^2＋ in different systems at the same initial heavy metal ion concentration. Under the experimental conditions, the isotherm biosorption of baker＇s yeast to the single system of Pb^2 ＋ , Cd^2 ＋ and the double system of Pb^2＋ -Cd^2＋ are well conformed with the Langmuir model, with the maximum absorption quantities （qmax） being 0.414 9 mmol/g, 0.346 8 mmol/g and 0.488 5 mmol/g, respectively. SEM/EDS analysis proves that Pb^2＋ and Cd^2＋ ions are absorbed by the baker＇s yeast tissues. It can also be found that it is the toxicity of heavy ions to yeast tissues make the tissues distorted and broken, which can probably be attributed to the response to the second biosorption process after the absorption took place some time later. In addition, the autoclaved baker＇ s yeast proves to have favorable biosorption effect on Pb^2＋ and Cd^2＋ . The toxicity of the two heavy metal ions, when put into spot combination and competition is expected to be helpful substances that affect the total biosorption in the double system of Pb^2＋-Cd^2＋ .
出处
《安全与环境学报》
CAS
CSCD
北大核心
2009年第4期54-58,共5页
Journal of Safety and Environment
基金
国家自然科学基金项目(10776027)
科技部欧盟国际合作专项资助项目(06zg0101)
关键词
环境生物学
面包酵母菌
生物吸附
动力学
等温吸附
environmental biology
baker＇ s yeast
biosorption
kinetics
isotherm absorption
