| 季铵型阳离子纤维素对水中腐殖酸的吸附 |
| Adsorption of Aqueous Humic Acid on QACC |
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| 摘要: 以异丙醇为分散剂，碱纤维与3-氯-2-羟丙基三甲基氯化铵反应，醚化接枝制得一种环境功能材料-季铵型阳离子纤维素（QACC）。用红外光谱、X-射线衍射和电镜扫描对材料的结构进行了表征：红外光谱中1644 cm-1处存在明显的季铵基的弯曲振动。经过改性的QACC结晶度下降，比表面积增加。研究了QACC对腐殖酸的吸附性能：pH=8、318K时，QACC对腐殖酸的饱和吸附容量为622mg·g-1；其表观活化能为6.45kJ·mol-1；吸附符合Lagergren二级动力学方程，吸附速率随温度升高而加快；吸附等温模型符合Langmuir等温式，为单分子层吸附；吸附腐殖酸的ΔH、ΔS、ΔG分别为：31.7 kJ·mol-1、119 J·mol-1·K-1、-5.34 kJ·mol-1，吸附主要为化学吸附。 |
| 关键词: 季铵型阳离子纤维素 腐殖酸 表征 动力学 热力学 吸附机理 |
| 基金项目: 国家自然科学基金（No.10872133）资助项目。 |
| Abstract: Quarternary ammonium cation cellulose (QACC) was synthesized by using 3-chloro-2-hydroxypropy-ltrimethylammonium chloride as etherifying agent with isopropyl alcohol as dispersing media. The synthesized QACCwas characterized by IR, XRD and SEM and was used for adsorption of humic acid, a precursor of disinfection by-products, from aqueous solution. The IRresults show that the bending vibration peak of R4N+ at 1637 cm-1 is obviously present, confirming that QACC is the target product. XRD and SEM results indicate a decreased crystallinity and an increased surface area of QACC caused by the etherification. The adsorption results reveal that the saturation humic acid adsorption capacity is 622 mg·g-1 at 318 Kunder pHvalue of 8. Furthermore, the adsorption process is fitted with pseudo-second-order kinetics model and the adsorption rate increases with increase of temperature. The apparent activation energy of the adsorption is 6.45 kJ·mol-1. The adsorption pattern fitted Langmuir isotherms (monomolecular layer adsorption). ΔH, ΔS and ΔG of the adsorption were 31.7 kJ·mol-1, 119 J·mol-1·K-1 and-5.34 kJ·mol-1, respectively. The results also show that the adsorption is mainly chemical adsorption. |
| Keywords: QACC humic acid characterization kinetic thermodynamics adsorption mechanism |
| 投稿时间：2014-04-03 修订日期：2014-05-25 |
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| 吴薇,施文健,王精志,顾海欣,杨琴淋.季铵型阳离子纤维素对水中腐殖酸的吸附[J].无机化学学报,2014,30(9):2057-2063. |
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