Thermodynamic, equilibrium and kinetic studies on biosorption of Pb+2 from aqueous solution by Bacillus pumilus sp. AS1 isolated from soil at abandoned lead mine
Thermodynamic, equilibrium and kinetic studies on biosorption of Pb+2 from aqueous solution by Bacillus pumilus sp. AS1 isolated from soil at abandoned lead mine
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DOI：
10.1016/j.jtice.2017.09.005
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发表时间：
2017-11
影响因子：
5.7
通讯作者：
Shayan Sayyadi;S. Ahmady-Asbchin;K. Kamali;N. Tavakoli
中科院分区：
文献类型：
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作者：
Shayan Sayyadi;S. Ahmady-Asbchin;K. Kamali;N. Tavakoli
In this study, a lead-resistant bacterium was isolated and used as an adsorbent to remove Pb+2from aqueous solution. The strain was identified and designated asBacillus pumilussp. AS1 based on the morphology and 16S rRNA sequence analysis. Biosorption of Pb+2from aqueous solutions using AS1 was investigated under various experimental conditions of pH, initial metal concentration, contact time and temperature. The optimum pH value was determined to be 4.0. Pseudo-second-order kinetic model was also found to be in good agreement with the experimental results. Thermodynamic parameters of the adsorption confirmed the endothermic nature of sorption process with positive heat of enthalpy, accompanied by a positive value of entropy change. The results of FTIR analysis suggested the involvement of carboxyl and hydroxyl groups during the biosorption process. Scanning electron microscopy and energy dispersive X-ray spectroscopy analyses showed that biosorption ofB. pumilussp. AS1 to Pb+2involved surface adsorption and ion exchange. Desorption experiments by treating biomass with 0.1 M HNO3solution resulted to more than 90% recovery of the adsorbed Pb+2from AS1, thereby indicating that Pb+2can be easily and quantitatively recovered from biomass.
