基于光谱学分析的生物磷参与暹罗芽孢杆菌对铀的去除行为及机制研究  

Removal Behavior and Mechanism of Uranium by Bacillus Siamensis Based on Spectroscopic Analysis: the Role of Biological Phosphorus

作　　者：周琳 董发勤[2] 张伟 唐子涵[5] 熊鑫 周磊 李冬坤 霍婷婷 陈晓明[5] 刘金凤[1,2] 冯晨旭 李若飞 ZHOU Lin;DONG Fa-qin;ZHANG Wei;TANG Zi-han;XIONG Xin;ZHOU Lei;LI Dong-kun;HUO Ting-ting;CHEN Xiao-ming;LIU Jin-feng;FENG Chen-xun;LI Ruo-fei(School of Materials Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,China;Key Laboratory of Solid Waste Treatment and Resource Recycle,Southwest University of Science and Technology,Mianyang 621010,China;Analytical and Testing Center,Southwest University of Science and Technology,Mianyang 621010,China;Research Center of Laser Fusion,China Academy of Engineering Physics,Mianyang 621900,China;School of Life Sciences and Engineering,Southwest University of Science and Technology,Mianyang 621010,China)

机构地区：[1]西南科技大学材料科学与工程学院,四川绵阳621010 [2]西南科技大学固体废物处理与资源化教育部重点实验室,四川绵阳621010 [3]西南科技大学分析测试中心,四川绵阳621010 [4]中国工程物理研究院激光聚变研究中心,四川绵阳621900 [5]西南科技大学生命科学与工程学院,四川绵阳621010

出　　处：《光谱学与光谱分析》2020年第1期22-28,共7页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(41802037,41572025);四川省科技计划项目(2017GZ0401);西南科技大学创新基金项目(18ycx077)资助

摘　　要：以暹罗芽孢杆菌为研究对象,它具有较高的表面积/体积比,吸附性能良好。前人关于暹罗芽孢杆菌的研究多集中在它降解纤维素淀粉或抗菌方面,关于暹罗芽孢杆菌与放射性核素的作用及机制基本未涉及。利用等离子发射光谱和等离子发射光谱-质谱研究溶液初始pH值、铀初始浓度、菌体用量等因素对暹罗芽孢杆菌去除铀的影响及作用过程中菌体释放的生物磷与铀去除的关系;利用红外光谱和扫描电镜对与铀作用前后的暹罗芽孢杆菌形貌及基团变化进行表征;利用X射线光电子能谱和扫描电镜能谱分析菌体表面元素分布情况和元素价态,进而探讨暹罗芽孢杆菌对铀的去除机制。结果表明,由于不同pH条件下暹罗芽孢杆菌生长活性、铀存在形态和磷元素释放量的不同,其对铀的去除差异很大。在pH 5.0时,暹罗芽孢杆菌对铀的去除效果最好。菌体用量增加有利于暹罗芽孢杆菌对铀的去除。对实验结果进行Langmuir和Freundlich等温吸附拟合后发现:暹罗芽孢杆菌对铀的去除行为符合Langmuir等温吸附模型;铀浓度实验获得的最大吸附量高于理论计算的最大吸附量,说明暹罗芽孢杆菌对铀的去除可能是物理和化学行为的共同作用。暹罗芽孢杆菌能够有效去除水体中的铀,实验获得的最大去除率为96.5%,最高吸附量为450.3 mg·g^-1,高于大部分已报道的用于吸附铀的芽孢杆菌。对反应前后菌体的扫描电镜测试发现,与铀作用后暹罗芽孢杆菌表面出现鳞片状沉淀, X射线光电子能谱和扫描电镜能谱分析表明该沉淀为含磷铀物质。结合红外光谱分析,推测暹罗芽孢杆菌去除铀的机制为:首先,通过静电作用铀被快速吸引到暹罗芽孢杆菌表面,随后以配位的形式被菌体上的磷酸基团、氨基、羟基、羧基等活性基团吸附,同时与菌体释放的含磷酸盐类物质相互作用,形成含磷铀沉淀而被固定至In this experiment, Bacillus Siamensis(B. siamensis) was taken as research object, and B. siamensis had a high ratio of surface area to volume, indicating that B. siamensis has a great performance on adsorbing heavy metals. However, the studies of previous experts and scholars on B. siamensis mostly focused on degradation of starch or cellulose and antifungal activity. And the mechanism of the interaction between B. siamensis and heavy metals or radionuclides was to tally not researched. Therefore, the purposes of this experiment were to use ICP-OES and ICP-MS to study the effects of pH value of solution, initial uranium concentration and biomass on removal of uranium by B. siamensis and the relationship between biological phosphorus released by cells and removal of uranium during the process, FTIR and SEM to characterize the morphology and group changes of B. siamensis before and after interaction with uranium, XPS and EDS to analyze the distribution and valence of elements on the surface of B. siamensis, and then the removal mechanism of uranium by B. siamensis was discussed. The results showed that the removal of uranium by B. siamensis under different pH varied greatly due to the difference of growth activities of B. siamensis, the existence forms of uranium and the amount of phosphorus element released by cells in the process under different pH values conditions. The removal effect was the best at pH=5.0. Increasing the biomass was beneficial to the removal of uranium by B. siamensis. The Langmuir and Freundlich adsorption isotherm models were used to fit the experimental data, and the fitting results showed that the removal behavior of uranium by B. siamensis conformed to the Langmuir isotherm adsorption model. And the maximum adsorption capacity obtained from the initial uranium concentration experiment was higher than the theoretical maximum adsorption capacity calculated from the Langmuir isotherm adsorption model, indicating that the removal of uranium by B. siamensis could be a combination of physical

关 键 词：暹罗芽孢杆菌 铀 磷 谱学分析 去除机制 

分 类 号：Q89[生物学]