Adsorption of Ag+ ions on hydrolyzed lignocellulosic materials based on willow, paulownia, wheat straw and maize stalks
Adsorption of Ag+ ions on hydrolyzed lignocellulosic materials based on willow, paulownia, wheat straw and maize stalks
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DOI：
10.1007/s13762-016-0970-y
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发表时间：
2016-04
影响因子：
3.1
通讯作者：
P. Vassileva;T. Radoykova;A. Detcheva;I. A. Avramova;K. Aleksieva;S. K. Nenkova;I. Valchev;D. R.
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文献类型：
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作者：
P. Vassileva;T. Radoykova;A. Detcheva;I. A. Avramova;K. Aleksieva;S. K. Nenkova;I. Valchev;D. R.
研究了植物秸秆（杨柳、泡桐、小麦秸秆和玉米秸秆）水解液对Ag+的吸附。进行化学分析以确定所得材料的组成。通过BET、IR、XPS、EPR等测试手段，对材料的吸附机理、吸附位和比表面积进行了研究。考察了接触时间、初始溶液酸度和Ag+浓度对反应的影响。采用伪一级、伪二级和颗粒内扩散模型对动力学数据进行了分析。在所有情况下，吸附的pH值的显着影响。不同类型的吸附等温线的Ag+离子（无论是朗缪尔或Freundlich）注册取决于吸附材料。吸附机理复杂，吸附过程经历了Ag+离子的聚集和Ag元素的形成等不同阶段。最大吸附容量为2.05 - 6.07 mg g−1。实验结果表明，木质纤维素废料是一种很有前途的Ag+吸附剂。
In the present work, the adsorption of Ag+ions on hydrolyzed plant biomass (willow, paulownia, wheat straw and maize stalks) was investigated. Chemical analyses were performed to establish the composition of the obtained materials. Adsorption mechanism, adsorption sites and specific surface areas of these materials were examined by BET analysis, IR spectroscopy, XPS and EPR. The effects of contact time, acidity of initial solutions and Ag+ion concentrations were followed. Pseudo-first-order, pseudo-second-order and intra-particle diffusion models were used to analyze kinetic data. In all cases, the adsorption was significantly affected by the pH value. Different types of adsorption isotherms of Ag+ions (either Langmuir or Freundlich) were registered depending on the adsorbing material. The adsorption mechanism is complex, and the process passes through different stages as clustering of Ag+ions and formation of elemental Ag. The maximal adsorption capacities varied from 2.05 to 6.07 mg g−1. The obtained results revealed that the examined waste lignocellulosic materials are promising adsorbents for Ag+ions.