摘要
为探究以芦苇灰为硅源制备有序多孔SBA-15的潜力,并弄清所获得的SBA-15对溶液中Cd2+离子的吸附性能。采用水热-后期接枝的合成方法,制备出三胺基改性SBA-15吸附剂(3N-SBA-15),通过批实验的方法讨论了吸附时间、体系pH、温度和离子强度等因素对水溶液中Cd2+吸附的影响及其再生研究,最后对Cd2+吸附机制进行了探讨。结果表明,合成的材料均具有高度规则的多孔特征,其对Cd2+的吸附受体系pH控制;胺基改性可以显著增强SBA-15对Cd2+的吸附能力。3N-SBA-15对溶液中Cd2+的吸附过程可用Langmuir模型描述,298 K时Cd2+的最大吸附量可达1.07 mmol/g,升温有利于吸附进行。0.01 mol/L EDTA和0.1 mol/L HCl溶液是3N-SBA-15较为合适的再生剂;3N-SBA-15对Cd2+的吸附机制可能为包含物理吸附、离子交换和络合反应等过程的复杂吸附过程。研究表明,3N-SBA-15是一种对水体Cd2+具有良好吸附能力的吸附材料,芦苇灰是制备SBA-15的一种潜在硅源。
In order to evaluate the potential of using reed ash as silica resource in preparation of pore highly ordered SBA-15 and to investigate its adsorption performance for Cd2 +ion from aqueous,a hydrothermal synthesis method followed by a grafting process was explored to prepare triamine-modified SBA-15( 3N-SBA-15) from reed ash. The adsorption performances of the 3N-SBA-15 for Cd2 +from aqueous solutions were investigated by the study of parameters such as contact time,solution pH,ionic strength,and adsorption temperature. The regeneration potential of the 3N-SBA-15 was evaluated as well. The adsorption mechanism was analyzed based on the observed data. The results showed that the prepared materials exhibited highly ordered mesoporous structures. The adsorption process for Cd2 +was controlled by the pH of the solutions. The amine-modification had the ability to significantly promote the Cd2 +adsorption. The Cd2 +adsorption was a spontaneous and endothermic process,which could be described by Langmuir model with the maximum Cd2 +adsorption capacity 1. 07 mmol /g at 298 K. The Cd2 +adsorption mechanism might be a complex adsorption process which contained physical adsorption,ion exchange and chelating reaction process. The solutions of 0. 01 mol /L EDTA and 0. 1 mol /L HCl were suitable for the regeneration of 3N-SBA-15. The study indicated that the 3N-SBA-15 was effective for Cd2 +adsorption from aqueous solutions,and the reed ash was a promising silica resource for SBA-15 preparation.
出处
《环境工程学报》
CAS
CSCD
北大核心
2014年第10期4393-4401,共9页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(41101288)
