Experimental probation on the binding kinetics and thermodynamics of Au(III) onto Bacillus subtilis
Experimental probation on the binding kinetics and thermodynamics of Au(III) onto Bacillus subtilis
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Au(III)与枯草芽孢杆菌结合动力学和热力学的实验探索
DOI：
10.1016/j.cej.2011.05.077
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发表时间：
2011-08-01
影响因子：
15.1
通讯作者：
Cai, Fang
中科院分区：
文献类型：
--
作者：
Ji, Yulan;Gao, Hong;Cai, Fang
在各种实验条件下（pH、生物量浓度、接触时间和温度）研究了枯草芽孢杆菌从水溶液中生物吸附 Au(III) 的情况。确定最佳pH值为2.0，在298-323 K范围内，随着温度的升高，Au(III)的吸附量减少。Au(III)的吸附在前10 min内进行得非常快，随后趋于达到平衡。人们发现 Au(III) 生物吸附更符合 Freundlich 模型，并且 Freundlich 模型为枯草芽孢杆菌提供了 355 mg/g 的最大 Au(III) 吸收能力。此外，伪二级动力学模型为实验数据提供了更好的相关性。然后根据获得的实验数据源计算热力学参数自由能（Delta G 度）、焓（Delta H 度）和熵（Delta S 度），这表明这种生物吸附是放热和自发的。最后，傅里叶变换红外 (FT-IR) 光谱检查了可能参与 Au(III) 和枯草芽孢杆菌之间相互作用的官能团。这说明工作官能团是氨基、羧基和羟基。这些结果表明枯草芽孢杆菌可用作有效的生物吸附剂以从水溶液中去除 Au(III)。 (C) 2011 Elsevier B.V. 保留所有权利。
The biosorption of Au(III) from an aqueous solution using Bacillus subtilis was investigated under various experimental conditions: pH, biomass concentration, contact time and temperature. The optimum pH value was determined to be 2.0, and Au(III) uptake reduced with the increase of temperature to within the range of 298-323 K. Au(III) adsorption proceeded very rapidly in the first 10 min and subsequently tended to achieve equilibrium. Au(III) biosorption was found to better fit the Freundlich model, and the Freundlich model provided a maximal Au(III) uptake capacity at 355 mg/g for B. subtills. Moreover, a pseudo-second-order kinetic model provided a better correlation for the experimental data. The thermodynamic parameters free energy (Delta G degrees), enthalpy (Delta H degrees) and entropy (Delta S degrees) were then calculated from an obtained experimental data source, which revealed this biosorption to be exothermic and spontaneous. Finally, Fourier transform infrared (FT-IR) spectroscopy examined the functional groups that might participate in the interaction between Au(III) and B. subtilis. which illustrated that the working functional groups were the amino, carboxyl and hydroxyl groups. These results indicate that B. subtilis can be used as an effective biosorbent to remove Au(III) from an aqueous solution. (C) 2011 Elsevier B.V. All rights reserved.