摘要: |
为考察李氏禾内生细菌蜡样芽孢杆菌Bacillus cereus J01菌株吸附Cr3+的性能,以蜡样芽孢杆菌B. cereus J01失活菌体作为生物吸附剂,采用单因素实验方法考察pH、温度、Cr3+初始浓度、吸附剂的用量、时间等条件对Cr3+吸附性能的影响,分析其等温吸附过程、动力学过程及热力学过程,采用红外光谱方法对吸附机理进行初步分析。结果表明:(1)在50 mL反应体系中,当pH值为6、温度为40 ℃、Cr3+初始浓度为150 mg·L-1、吸附剂投加量为0.2 g、吸附时间为12 h时,蜡样芽孢杆菌B. cereus J01失活菌体对Cr3+的吸附性能达到最佳,其平衡吸附量和Cr3+去除率分别为34.30 mg·g-1、91.60%。(2)等温吸附过程分析得Langmuir吸附等温模型能更好地模拟蜡样芽孢杆菌B. cereus J01失活菌体对Cr3+的吸附,其吸附过程更倾向于单分子层吸附。(3)吸附动力学分析得蜡样芽孢杆菌B. cereus J01失活菌体对Cr3+的吸附更符合准二级动力学速率方程。(4)吸附热力学分析显示,在40 ℃下,吸附过程的△G、△H和△S分别为-2.609 kJ·moL-1、61.792 kJ·moL-1和206.11 J·moL-1,该温度下吸附过程是自发过程。(5)红外光谱分析结果显示,蜡样芽孢杆菌B. cereus J01失活菌体对Cr3+的吸附可能通过细胞成分中的氨基、羟基和羰基起作用。说明该菌的失活菌体对Cr3+具有较强的吸附性能,在环境铬污染的治理中具有较好的应用潜力。 |
关键词: 蜡样芽孢杆菌,吸附,Cr3+,李氏禾,内生细菌 |
DOI:10.11931/guihaia.gxzw202304007 |
分类号: |
Fund project:广西自然科学基金(2016GXNSFAA380014);国家自然科学基金项目(31460409) |
|
Study on adsorption of chromium by endophytic bacteria Bacillus cereus J01 isolated from Leersia hexandra Swartz |
ZHANG Ze-Yu1,2, LI Zi-Yuan1,2, WANG Shao-Yang1,2, CHEN Xin-Yi1,2, WANG Li-Qi1,2, LI Hai-Yun1,2
|
1.College of Chemistry &2.Bioengineering, Guilin University of Technology
|
Abstract: |
In order to investigate the adsorption performance of Cr3+ by endophytic bacterium Bacillus cereus J01 from Leersiahexandra Swartz, the effects of pH, temperature, initial concentration of Cr3+, dosage of adsorbent, time and other factors on the adsorption capacity of Cr3+ were investigated by single factor test method using inactivated Bacillus cereus J01 strain as biological adsorbent. The isothermal adsorption process, kinetic process and thermodynamic process were also analyzed. The adsorption mechanism of Cr3+ was preliminarily analyzed by infrared spectroscopy. The results showed that: (1) In a adsorption system of 50 mL, inactivated Bacillus cereus J01 strain had the best adsorption performance on Cr3+ with the conditions as follows: initial pH of 6, temperature of 40℃, initial Cr3+concentration of 150 mg/L, adsorbent dosage of 0.2 g and adsorption time of 12 h. The equilibrium adsorption capacity and Cr3+ removal rate were 34.30 mg/g and 91.60%, respectively. (2) Analysis of isothermal adsorption process Langmuir adsorption isothermal model could better simulate the adsorption of Cr3+ by Bacillus cereus J01 inactivated bacteria, and its adsorption process was more inclined to monolayer adsorption. (3) Adsorption kinetics analysis showed that the adsorption of Cr3+ by Bacillus cereus J01 inactivated was more consistent with the quasi-second-order kinetic rate equation. (4) The thermodynamic analysis of adsorption shows that at 40 ℃, the △G, △H and △S of the adsorption process are -2.609 kJ/mol, 61.792 kJ/mol and 206.11 J/mol, respectively. The adsorption process is spontaneous at this temperature. (5) Infrared spectrum analysis showed that Bacillus cereus J01 inactivated Bacillus could adsorb Cr3+ through amino, hydroxyl and carbonyl groups in the cell components. |
Key words: Bacillus cereus, adsorption, chromium, Leersia hexandra Swartz, endophytic bacterium |