石英砂-腐殖酸-Cupriavidus gilardii CR3复合体对铜离子的吸附特性及机理研究

Study on Characteristics and Mechanism of Copper Ions by Quartz Sand-humic Acid-Cupriavidus gilardii CR3

[目的]研究pH、初始铜离子浓度和吸附时间对石英砂-腐殖酸-Cupriavidus gilardii CR3复合体吸附铜离子的影响。[方法]利用等温吸附模型和动力学模型拟合试验数据,通过测定复合体吸附铜离子前后的Zeta电位、扫描电子显微镜-能谱(SEM-EDS)和傅里叶红外光谱(FTIR),研究吸附剂对铜离子的吸附特性及机理。[结果]pH是影响吸附能力的主要因素,静电作用可使复合体表面负电荷增多,提高吸附量。在最适pH(5.0)下,复合体对铜离子的最大吸附量为13.08 mg/g。复合体对铜离子的吸附过程符合化学单分子吸附的Langmuir模型和二级动力学模型。[结论]该研究认为静电作用和单分子化学吸附是石英砂-腐殖酸-Cupriavidus gilardii CR3复合体吸附铜离子的主要机制。

[Objective]To study the effect of pH,initial copper ions concentration and contact time on composites of sand-humic acid-Cupriavidus gilardii CR3.[Methods]Experimental data were simulated by adsorption isotherms and kinetics.Adsorption characteristics and mechanism of copper ions by adsorbents was studied by determining the Zeta potential before and after adsorption of copper ions,and scanning SEMEDS and FTIR.[Results]The results showed that pH was important parameters for the adsorption capacity of composites for copper ions.Electrostatic effect increased the negative charge on the surface of composite,and increased adsorption capacity.At the optimum pH（5.0）,the maximum adsorption capacity of the complex was 13.08 mg/g.The adsorption process of copper ions by composites of sand-humic acidCupriavidus gilardii CR3 was in according with Langmuir model and two order kinetic model.[Conclusion]The study considered that electrostatic interaction and single molecule chemical adsorption were the main mechanisms of adsorption of copper ions by composites of sand-humic acid-bcateria.