The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing, PR China.
J Hazard Mater. 2012 Aug 15;227-228:461-8. doi: 10.1016/j.jhazmat.2012.05.004. Epub 2012 May 9.
Cetyltrimethylammonium bromide (CTAB) modified magnetic nanoparticles (Fe(3)O(4)@CTAB) were synthesized and used to remove arsenate from water. Fe(3)O(4)@CTAB was prepared by a modified simple co-precipitation process with cheap and environmental friendly iron salts and cationic surfactant CTAB. Powder X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infra-red spectroscopy were utilized to characterize the prepared adsorbent (Fe(3)O(4)@CTAB). Transmission electron microscopy (TEM) image showed that Fe(3)O(4)@CTAB particles were approximately spherical with the core size of 10 nm. With a saturation magnetization of 67.2 emu g(-1), the Fe(3)O(4)@CTAB nanoparticles could be easily separated from solutions with a simple magnetic process in very short time (within 5 min). Adsorption of arsenate on Fe(3)O(4)@CTAB reached equilibrium within 2 min at pH 6. Arsenate adsorption agreed well with pseudo-second order kinetic model and two-site Langmuir isotherm model with the arsenate adsorption capacity of 23.07 mg g(-l), which was twice greater than that of pure Fe(3)O(4). Arsenate removal rate was over 90% at a wide pH range from 3 to 9 and the removal of arsenate was not obviously affected by the presence of dissolved natural organic matter (up to 10 mg L(-1) as TOC) and competitive anions (sulfate, bicarbonate, and silicate up to 20 mg L(-1), and phosphate up to 5 mg L(-1)) in solutions. Fe(3)O(4)@CTAB could be regenerated in alkali solutions and more than 85% As(V) was removed even in fifth regeneration/reuse cycle.
十六烷基三甲基溴化铵（CTAB）修饰的磁性纳米粒子（Fe(3)O(4)@CTAB）被合成并用于从水中去除砷酸盐。Fe(3)O(4)@CTAB 通过一种改良的简单共沉淀工艺，使用廉价且环保的铁盐和阳离子表面活性剂 CTAB 制备。粉末 X 射线衍射、X 射线光电子能谱和傅里叶变换红外光谱用于对制备的吸附剂（Fe(3)O(4)@CTAB）进行表征。透射电子显微镜（TEM）图像表明，Fe(3)O(4)@CTAB 颗粒近似为球形，核心尺寸为 10nm。Fe(3)O(4)@CTAB 纳米粒子的饱和磁化强度为 67.2 emu g(-1)，可以通过简单的磁处理在很短的时间（5 分钟内）内从溶液中轻松分离。在 pH 值为 6 时，砷酸盐在 Fe(3)O(4)@CTAB 上的吸附在 2 分钟内达到平衡。砷酸盐的吸附符合准二级动力学模型和双位 Langmuir 等温线模型，砷酸盐的吸附容量为 23.07mg g(-1)，是纯 Fe(3)O(4)的两倍。砷酸盐的去除率在 3 至 9 的宽 pH 范围内超过 90%，并且砷酸盐的去除不受溶液中存在的溶解天然有机物（高达 10mg L(-1)作为 TOC）和竞争阴离子（硫酸盐、碳酸氢盐和硅酸盐高达 20mg L(-1)，磷酸盐高达 5mg L(-1)）的明显影响。Fe(3)O(4)@CTAB 可以在碱溶液中再生，即使在第五次再生/再利用循环中，也可以去除超过 85%的 As(V)。
