摘要
以蒙脱石K10为原料,制备出OH/Fe摩尔比分别为0.6、0.8、1.0、1.5和2.0的系列羟基铁柱撑蒙脱石吸附剂(OH/Fe蒙脱石),比较它们对庆大霉素的吸附能力,研究pH值和时间等因素对OH/Fe蒙脱石吸附庆大霉素的影响规律,并分析吸附机理。结果表明:柱撑OH/Fe蒙脱石对庆大霉素吸附量从低到高依次为K10(33.3 mg/g)、0.6 OH/Fe(43.4 mg/g)、0.8 OH/Fe(44.8 mg/g)、1.0 OH/Fe(56.0 mg/g)、2.0 OH/Fe(64.8 mg/g)、1.5 OH/Fe(71.9 mg/g),OH/Fe摩尔比为1.5时吸附量最大,达到K10的2倍以上,符合Freundlich吸附等温线。柱撑蒙脱石对庆大霉素的吸附在3 h内接近吸附平衡,并且吸附量随pH值的增加而显著增加,吸附可用伪二阶动力学方程描述。吸附量增大主要归功于柱撑后蒙脱石层间距增大,阳离子交换是庆大霉素进入蒙脱石的主导机制,表面配位的化学吸附也是另一种辅助机制,同时羟基铁柱撑蒙脱石吸附庆大霉素后柱撑结构易坍塌。
The hydroxyl-Fe pillared montmorillonite complexes at different OH/Fe molar ratios （i.e., 0.6, 0.8, 1.0, 1.5 and 2.00H/Fe montmorillonite） were prepared with purified montmorillonite samples （K10） as raw materials. The adsorption interaction of aminoglycoside antibiotics with both OH/Fe montmorillonite and K10 were investigated at various pH values of sorption solution and time on the adsorption of the OH/Fe. The adsorption materials were analyzed by X-ray diffraction, Fourier transformed infrared spectoscopy and X-ray photoelectron spectroscopy, respectively. The results show that the order of gentamicin equilibrium sorption amount of OH/Fe from low to high is K10（33.3mg/g）, 0.6OH/Fe（43.4mg/g）, 0.80H/Fe（44.8mg/g）, 1.00H/Fe（56.0mg/g）, 2.00H/Fe（64.8mg/g）, 1.50H/Fe（71.9 mg/g）. The 1.50H/Fe has the maximum adsorption capacity, which is 2 times greater than that of K10. The Freundlich model can well fit the adsorption isotherms of gentamicin by both OH/Fe and K10. It is indicated that the adsorption capacity of gentamicin can reach the equilibrium after 3 h, that the adsorption capacity of gentamicin on pillared montmorillonite increases with the increase of pH value, which can be described by the pseudo second-order kinetic equation. The analysis of adsorption mechanism shows that the adsorption capacity of OH/Fe increase mainly due to the increase of the interlayer distance of montmoriUonite pillared, and that cation exchange is the dominant mechanism of gentamicin entering montmorillonite interlayer, and the chemical adsorption of surface comptexing is also one of the adsorption mechanisms. The adsorption of gentamicin into hydroxyl-Fe pillared montmorillonite can cause the collapse of structure and the decrease of interlayer region.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2016年第2期314-321,共8页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金青年科学基金(21303019)
福建省自然科学基金(2015J01197)
关键词
蒙脱石
羟基铁柱撑
庆大霉素
吸附
montmorillonite
hydroxyl-iron intercalated
gentamicin
adsorption
