State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.
J Environ Sci (China). 2010;22(9):1327-34. doi: 10.1016/s1001-0742(09)60258-8.
Natural zeolite was modified by loading cetylpyridinium bromide (CPB) to create more efficient sites for humic acid (HA) adsorption. The natural and CPB modified zeolites were characterized with X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy and elemental analysis. The effects of various experimental parameters such as contact time, initial HA concentration, solution pH and coexistent Ca2+, upon HA adsorption onto CPB modified zeolites were evaluated. The results showed that natural zeolite had negligible affinity for HA in aqueous solutions, but CPB modified zeolites exhibited high adsorption efficiency for HA. A higher CPB loading on natural zeolites exhibited a larger HA adsorption capacity. Acidic pH and coexistent Ca2+ were proved to be favorable for HA adsorption onto CPB modified zeolite. The kinetic process was well described by pseudo second-order model. The experimental isotherm data fitted well to Langmuir and Sips models. The maximum monolayer adsorption capacity of CPB modified zeolite with surfactant bilayer coverage was found to be 92.0 mg/g.
天然沸石通过负载十六烷基溴化吡啶（CPB）进行改性，以创造更有效的腐殖酸（HA）吸附位点。用 X 射线衍射、场发射扫描电子显微镜、傅里叶变换红外光谱和元素分析对天然沸石和 CPB 改性沸石进行了表征。评价了接触时间、初始 HA 浓度、溶液 pH 值和共存 Ca2+等各种实验参数对 CPB 改性沸石上 HA 吸附的影响。结果表明，天然沸石在水溶液中对 HA 几乎没有亲和力，但 CPB 改性沸石对 HA 表现出很高的吸附效率。天然沸石上 CPB 的负载量越高，HA 的吸附容量越大。酸性 pH 值和共存的 Ca2+被证明有利于 CPB 改性沸石上 HA 的吸附。动力学过程很好地符合准二级模型。实验等温线数据很好地符合朗缪尔和 Sips 模型。具有表面活性剂双层覆盖的 CPB 改性沸石的最大单层吸附容量被发现为 92.0 mg/g。
