摘要
用乙醇及氢氧化钠对蔗渣进行处理,得到改性蔗渣(MB)。通过扫描电镜、X射线衍射及傅里叶变换红外光谱对改性前后蔗渣进行了表征分析,通过静态吸附试验,研究了反应时间、反应温度、溶液的p H、Cd2+初始浓度、共存离子(Ca2+,Mg2+和Na+)对MB吸附Cd2+的影响。结果表明,改性蔗渣的比表面积增大,蔗渣原有的晶格结构被破坏,羟基的活性增强。MB对Cd2+的吸附适宜p H为4.0~6.0;MB对Cd2+吸附平衡时间为20 min;MB对Cd2+的吸附过程的吸附等温线结果发现表明MB对Cd2+的吸附是化学吸附,MB对Cd2+的饱和吸附量为14.450 mg/g。MB对Cd2+的吸附过程符合准二级动力学模型。热力学研究结果表明,MB对Cd2+的吸附过程是自发的放热过程。共存离子Ca2+,Mg2+和Na+对MB吸附Cd2+影响的顺序为Na+<Ca2+<Mg2+。
In this study, bagasse was modified by ethanol and sodium hydroxide to produce adsor- bent （kIB）. Then the surface morphology characterization of unmodified and modified bagasse get by used scanning electron microscope, infrared spectrometer and X-ray diffraction. The feasibility of using MB for adsorption cadmium from aqueous solutions was investigated under different experimental conditions. The influence factor such as pH, reaction time, initial metal ions concentration and coex- istence cations （ Ca2＋, Mg2＋ Na＋ ） has been investigated for the adsorption of cadmium. The results showed that the specific surface area of modified sugarcane bagasse was increased. The lattice struc- ture of bagasse was destroyed after modified and the hydroxyl activity was increased. The optimum pH was ranged from 4 to 6, the adsorption equilibrium time was 20 minutes. The result for simulation of isotherm show that the adsorption rate was controlled by chemical adsorption and the maximum ad- sorption capacities of Cd2＋was 14. 450 mg/g. The adsorption kinetic data followed a pseudo-second order model. The thermodynamic results show that the adsorption of cadmium （Ⅱ） by MB was spon- taneous and exothermic. The coexistence cations（ Ca2＋ ,Mg2＋ ,Na＋） affected the adsorption of Cd2＋ in the follow oder ：Na＋〈 Ca〉〈 Mg2＋.
出处
《广西大学学报（自然科学版）》
CAS
北大核心
2015年第5期1314-1322,共9页
Journal of Guangxi University（Natural Science Edition）
基金
国家自然科学基金资助项目(41461091)
广西科学研究与技术开发计划基金资助项目(2014DD29046)
广西自然科学基金资助项目(2014GXNSFAA18039)
关键词
改性蔗渣
吸附
Cd2+
modified bagasse
adsorption
Cadmium （Ⅱ）
