(成都信息工程学院 资源环境学院,成都 610225)
摘 要: 研究抗铅产絮菌株B-07胞外聚合物EPS-07作为吸附剂处理含Pb(Ⅱ)的废水的吸附性能。结果表明:当吸附时间为80 min,pH为5.5,吸附剂用量为0.8 g/L,溶液中Pb(Ⅱ)初始浓度为50 mg/L时,EPS-07对铅离子的吸附平衡容量为61.5 mg/g。吸附等温式能较好地用Langmuir模型表达,吸附动力学很好地符合准二级动力学模型。FT-IR结果表明,EPS-07与Pb(Ⅱ)的作用过程中,主要是羟基、羧基等基团参与了吸附作用。SEM观察显示EPS-07表面结构比较松散,EPS-07与Pb(Ⅱ)作用后, 其表面变得致密并有结晶沉淀物出现。EDS图出现了Pb元素峰,表明 Pb(Ⅱ)被吸附到EPS-07上面。
关键字: 生物吸附;克雷伯氏菌;胞外聚合物;Pb(Ⅱ)
(College of Resource and Environment, Chengdu University of Information Technology, Chengdu 610225, China)
Abstract:The biosorption characteristics of extracellular polymeric substance (EPS-07) of producing flocculant strain B-07 as lead-resistant for the removal of Pb(Ⅱ) from aqueous solution were studied. The results show that the extent of adsorption capacity is 61.5 mg/g when the dosage of EPS-07 is 0.8 g/L, pH=5.5, adsorption contact time is 80 min, initial Pb(Ⅱ) concentration of aqueous solution is 50 mg/L, respectively. The biosorption equilibrium data are better described by Langmuir isotherm model, and the adsorption reaction of Pb(Ⅱ) by EPS-07 follows the second-order kinetic model. The carboxy, hydroxyl groups of EPS-07 are involved in chemical interaction with the Pb(Ⅱ) ions depicted by Fourier transform infrared spectroscopic (FT-IR) results. Moreover, SEM observation indicates that the EPS-07 surface is loose, and then obviously changes to campact after the EPS-07 surface loaded with with Pb(Ⅱ), where cry stalline deposits are deposited on the EPS-07 surface. Also, biosorption of Pb(Ⅱ) is confirmed by EDS analysis, which reveales the presence of Pb(Ⅱ) signals on the EPS-07 surface.
Key words: biosorption; Klebsiella pneumonia; extracellular polymeric substance; Pb(Ⅱ)