鸡源嗜铅菌JT_1菌株体外吸附铅的机理

Mechanism of Lead Binding of Lead-resistant Bacteria JT_1 in Vitro

以嗜铅鸡源肠球菌JT_1为生物吸附剂,研究该菌株在体外对铅的吸附机理。首先研究该菌的吸附等温模型和吸附动力学特征;再应用扫描电子显微镜和EDS能谱进行观察,分析JT_1吸附反应发生部位;最后,应用傅里叶变换红外光谱仪对其吸附铅有关的功能基团的特征进行验证。结果表明,JT_1吸附过程符合Langmuir吸附等温模型;整个吸附过程遵循伪二级吸附动力学模型;扫描电子显微镜照片显示,菌体表面有沉积物堆积;EDS能谱分析表菌体表面吸附的是铅沉积物;傅里叶红外变换光谱研究显示,菌体表面的氨基、羧基、羟基和磷酸基等官能团参与对铅的吸附。由此,JT_1对铅的吸附主要是表面吸附,菌体表面的一些官能团参与了吸附过程。

The lead-resistant bacteria from chicken JT1 was used as biosorbent,the mechanism of lead binding of JT1 in vitrowere studied in this paper.Firstly,the adsorption isotherm and adsorption kinetics characteristics were studied.Then Scanning electron microscope（SEM） and Energy Dispersive Spectrometer（EDS） were used to observe the surface of JT1 to examine the adsorption reaction sites.The end,Fourier transform infrared spectroscopy（FTIR） was applied to investigate the functional groups which take part in the biosorption process.The results showed that Langmuir isotherm model fitted well to describe the isotherm data.The process was found to follow the pseudo second order rate kinetics throughout the period.Scanning electron micrographs showed accumulation of lead ions on the surface of the biomass.From the FTIR study,involvement of various functional groups like amine,carboxyl,hydroxyl,phosphate,etc.for the binding of lead ions was evident.Therefore,surface adsorption of lead plays a major role,various functional groups on JT1 were involved in the adsorption.