| 丁二酸改性茶油树木屑吸附铀的研究 |
| 摘要点击 1942 全文点击 1024 投稿时间：2014-07-01 修订日期：2015-01-02 |
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| 中文关键词 生物吸附 铀 改性 茶油树木屑 丁二酸 |
| 英文关键词 biosorption uranium modification tea oil tree sawdust succinic acid |
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| 中文摘要 |
| 为了探究丁二酸改性对茶油树木屑吸附铀的促进作用,将茶油树木屑经过粉碎、筛分、碱化和酸化等前处理后,再利用丁二酸对茶油树木屑作改性处理. 红外分析表明改性后木屑内部的化学基团中增加了羧基、酯基; 扫描电镜可知,改性后的茶油树木屑由致密平直的条状结构变为疏松褶皱的叶片状结构,说明改性作用增加木屑内部的空隙. 通过静态吸附实验,考察了吸附反应时间、木屑用量、pH值、温度、以及溶液初始浓度等因素对茶油树木屑改性前后吸附铀的影响; 结果表明,茶油树木屑经丁二酸改性后对铀吸附效果明显提高,在12.5mg ·L-1的铀溶液中约提高了20%. 改性和未改性的茶油树木屑对铀的吸附都在180 min内达到平衡,并且都符合准二级动力学模型. 改性和未改性茶油树木屑对铀的吸附等温线都符合Langmuir和Freundlich模型. 且由Langmuir等温方程计算可知,在35℃、pH=4.0条件下,改性后的茶油树木屑对铀的最大吸附容量(Qm)由21.4133 mg ·g-1提高到31.5457 mg ·g-1. |
| 英文摘要 |
| In order to explore how the modification of succinic acid improves the adsorption of tea oil tree sawdust for uranium, the tea oil tree sawdust was modified by succinic acid, after the pretreatments of crushing, screening, alkalization and acidification. Infrared analysis indicated carboxylic acid groups and ester groups were added to the sawdust after modification, and scanning electron microscope demonstrated after modification the appearance of tea oil tree sawdust was transferred from the structure like compact and straight stripped into the structure like loose and wrinkled leaves, which meant modification increased its inner pores. By the static experiments, effects of reaction time between adsorbent and solvent, dosage of adsorbent, temperature, pH value and initial concentration of uranium were investigated. The results showed that after the modification by succinic acid, the absorption rate of tea oil tree sawdust for uranium increased significantly by about 20% in 12.5 mg ·L-1 initial concentration uranium solution. Adsorption equilibrium was achieved within 180 min, and the kinetic data can be well described by the pseudo-second-order kinetic model. The experimental adsorption isotherm followed the Langmuir and Freundlich models. In addition, the maximum adsorption amounts of tea oil tree sawdust after modification calculated from Langmuir equation raised from 21.4133 to 31.5457 mg ·g-1 at 35℃ and pH 4.0. |
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