• 关键词：鲍希瓦氏菌  贵金属金  生物吸附  动力学  热力学  吸附机理

• 基金项目：国家自然科学基金(No.51178191)

• 操艳兰
• 华南理工大学环境与能源学院, 广州 510006

• 朱能武
• 1. 华南理工大学环境与能源学院, 广州 510006;2. 工业聚集区污染控制与生态修复教育部重点实验室, 广州 510006

• 石超宏
• 华南理工大学环境与能源学院, 广州 510006

• 吴平霄
• 1. 华南理工大学环境与能源学院, 广州 510006;2. 工业聚集区污染控制与生态修复教育部重点实验室, 广州 510006

• 摘要：吸附是生物回收贵金属的重要环节,本文考察了溶液pH、生物量、初始Au³⁺浓度和温度对鲍希瓦氏菌吸附Au³⁺的影响,研究了鲍希瓦氏菌吸附Au³⁺的动力学和热力学特性,并初步探讨了吸附发生的可能机理.结果表明,pH明显影响鲍希瓦氏菌对Au³⁺的吸附,最佳pH为2~3.在初始Au³⁺浓度为115 mg·L^-1时,不同温度下90%的Au³⁺可在10 min内被吸附,4 h后基本达到吸附平衡,且吸附容量随着温度的升高而增加.吸附符合Freundlich等温线模型(R²=0.954),最大吸附容量为148.7 mg·g^-1.吸附动力学可用拟二级动力学方程描述(R²=0.999).热力学分析显示,鲍希瓦氏菌吸附Au³⁺是自发的吸热过程.傅里叶红外和X射线光电子能谱分析表明,氨基、羧基和羟基是起主要作用的官能团,其中,质子化的氨基作用机理主要是静电吸附.

• Abstract：The effects of pH, biomass dosage, initial Au³⁺ concentration and temperature on the biosorption of Au³⁺ by S.haliotis were evaluated. Meanwhile, kinetics, thermodynamics and possible mechanism were explored. The results indicated that pH was the dominant factor and the optimal initial pH was 2.0~3.0. Within the temperature range in investigation, more than 90% of Au³⁺ was adsorbed within the first 10 min and the equilibrium was reached within 4 h. In addition, the biosorption capacity was found to increase with temperature. Freudlich model provided a good correlation for the biosorption (R²=0.954) with maximum capacity of 148.7 mg·g^-1. The biosorption can be fitted by pseudo-second-order kinetics (R²=0.999). The thermodynamic parameters revealed that the biosorption was a spontaneous and endothermic process. Finally, Fourier transform infrared spectra and XPS revealed that amine, carboxyl, and hydroxyl might the major functional groups involved in the biosorption process and electrostatic sorption was the main mechanism involved in the protonated amino groups.

• Key words：Shewanella haliotis  gold ions  biosorption  kinetics  thermodynamics  mechanism

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