HDTMAB改性蒙脱石对二氯喹啉酸的吸附研究

丁春霞; 何紫君; 郑 琛; 蔡利民; 龚道新

文章摘要

丁春霞,何紫君,郑琛,蔡利民,龚道新.HDTMAB改性蒙脱石对二氯喹啉酸的吸附研究[J].农业环境科学学报,2014,33(9):1755-1761.

HDTMAB改性蒙脱石对二氯喹啉酸的吸附研究

Quinclorac Adsorption on HDTMAB-modified Montmorillonite

DOI：10.11654/jaes.2014.09.013

中文关键词: 二氯喹啉酸 HDTMAB 改性吸附

英文关键词: quinclorac HDTMAB modification adsorption

基金项目:

作者	单位
丁春霞	湖南农业大学理学院，长沙 410128；湖南农业大学烟草研究院，长沙 410128
何紫君	湖南农业大学理学院，长沙 410128
郑琛	湖南农业大学资源环境学院，长沙 410128
蔡利民	湖南农业大学资源环境学院，长沙 410128
龚道新	湖南农业大学烟草研究院，长沙 410128；湖南农业大学资源环境学院，长沙 410128

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中文摘要:

以天然蒙脱石为原料，十六烷基三甲基溴化铵（HDTMAB）为改性剂，制备用于去除水中二氯喹啉酸的吸附剂。借助X射线衍射（XRD）和傅里叶红外光谱仪（FT-IR）对制备的吸附剂进行结构表征，结果表明：HDTMAB成功负载于蒙脱石层间，增大了蒙脱石的层间距。同时，采用批量平衡技术，考察了接触时间、初始浓度、温度、pH值、吸附剂用量对HDTMAB改性蒙脱石对二氯喹啉酸吸附的影响，结果表明：经HDTMAB改性后的蒙脱石对二氯喹啉酸的吸附容量有了显著的提高，其吸附动力学符合准二级动力学模型，化学吸附为速率控制步骤；二氯喹啉酸吸附平衡数据可用Linear 和Freundlich模型较好地拟合；在二氯喹啉酸初始浓度为10.00 mg·L-1时，当温度由25 ℃升高到45 ℃，HDTMAB改性蒙脱石对二氯喹啉酸的吸附容量从1.86 mg·g-1减小到1.65 mg·g-1，吸附为放热过程；吸附容量随着二氯喹啉酸溶液pH值的增大而减小。

英文摘要:

Natural montmorillonite, characteristized with high hydrophilicity, shows little adsorption of non-polar organic substances. This study examined the adsorption of quinclorac on the montmorillonite modified by hexadecyltrimethyl ammonium bromide（HDTMAB） as influenced by contact time, adsorbate concentration, temperature, pH and adsorbent doses. The modified adsorbent was also characterized by X-ray diffraction（XRD） and Fourier transform infrared spectroscopy（FT-IR）. HDTMAB was adsorbed in the interlayer of montmorillonite, which expanded the layer spacing of the modified montmorillonite. The modified montmorillonite exhibited higher quinclorac removal efficiency than the unmodified montmorillonite did. The experimental data was fitted very well with the pseudo-second-order kinetic model, indicating that chemisorption was the controlling step of the adsorption. The adsorption isotherm of quinclorac was in good agreement with Linear and Freundlich isotherm models. The adsorption capacity decreased from 1.86 mg·g-1 to 1.65 mg·g-1 with temperature increase from 25 ℃ to 45 ℃ at an initial concentration of 10.00 mg·L-1, suggesting that the adsorption was exothermic. Adsorption capacity of quinclorac on modified montmorillonite decreased with increased pH.

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