三种微生物对铀的吸附行为研究

摘要

To compare the similarities and differences of adsorption properties and adsorption properties during interaction of microorganisms with uranium, we selected Bacillus subtilis (bacteria), yeast (fungus), chlorella (algae) as objects and studied the adsorption performance and a variety of microbial factors by using scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results indicated that three types of microorganisms in water uranium has good effect on uranium adsorption. The best adsorption rate of uranium by yeast and chlorella and Bacillus subtilis were 97.19%、97.13% and 98.03%, respectively. And the maximum adsorption capacity of uranium by yeast and chlorella and Bacillus subtilis were 341.2、356.5、512.5mgU/g(DW) , respectively. The adsorption process and mechanism for uranium adsorption by three kinds of microbe was different, yeast and chlorella in line with the Langmuir model, bacillus subtilis is more suitable for the Freundlich model. The results of Scanning electron microscope and energy spectrum indicated that the uranium is adsorbed onto the cell surface at the beginning with no precipitation or mineral. Then, the sheet and clumps of uranium-phosphorus crystallization were formed on the surface of yeast after 12hours.however, There were not found the similar crystals on the surface of chlorella and bacillus subtilis. Interaction of microorganisms with uranium will cause changes in cell morphology, especially for bacillus subtilis and chlorella.%开展了酵母菌(真菌)、枯草芽孢杆菌(细菌)、小球藻(藻类)对水体中铀(Ⅵ)的吸附性能及机理研究.结果表明：3种微生物对铀都具有较好的吸附效果.酵母菌,小球藻,枯草芽孢杆菌对铀的最佳吸附率分别为97.19%、97.13%、98.03%；且最大吸附量分别达到341.2、356.5、512.5mgU/g(DW).3种微生物对铀的吸附过程和机理有所不同,酵母菌和小球藻符合Langmuir模型,枯草芽孢杆菌更适合Freundlich模型,吸附至12h,酵母菌表面逐渐出现铀和磷的片状结晶及含铀沉积物堆积,小球藻和枯草芽孢杆菌与铀(50mgU/L)作用后细胞出现明显变形,菌体表面未出现铀的结晶物.