Faculty of Engineering and the Environment, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
Water Res. 2012 Aug;46(12):3913-22. doi: 10.1016/j.watres.2012.04.032. Epub 2012 Apr 30.
The preparation and testing of thiol-functionalised silica-coated magnetite nanoparticles (TF-SCMNPs) is described. The characteristics of these particles are assessed at different stages in the production process using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), and a magnetometer. The particles were found to be almost spherical with a uniform mesoporous structure with a pore size of ∼2.1nm. The particles were strongly responsive to an external magnetic field making separation from solution possible in less than 1min. The adsorption characteristics of the particles were quantified in a series of isotherm experiments using Hg(II) solution concentrations between 40 and 1000μg l(-1) at adsorbent concentrations of 4 and 8mg l(-1). The adsorption capacity was higher than for other commonly used adsorbents with 90% of Hg(II) removed during the first 5min and equilibrium in less than 15min. Both the Langmuir and Freundlich isotherm models were applied to the isotherm data and the maximum adsorption capacity was achieved when the ratio of adsorbent to adsorbate was low. Both temperature and pH had an effect on adsorption but when the TF-SCMNPs were used for removal of Hg(II) from tap water and bottled water, which contained other ions, there appeared to be no interference. Hg(II) could be successfully desorbed using thiourea in a 3M HCl solution; this did not result in the destruction of the nanoparticles and they could subsequently be reused without loss of their activity in repetitive adsorption tests.
本文描述了巯基功能化硅壳修饰的磁铁矿纳米粒子（TF-SCMNPs）的制备和测试。在生产过程的不同阶段，使用 X 射线衍射（XRD）、透射电子显微镜（TEM）、傅里叶变换红外光谱（FTIR）和磁力计评估了这些粒子的特性。这些粒子几乎呈球形，具有均匀的介孔结构，孔径约为 2.1nm。粒子对外界磁场的响应很强，使得在不到 1min 的时间内就可以从溶液中分离出来。在一系列等温实验中，使用浓度为 40 至 1000μg l(-1)的 Hg(II)溶液和浓度为 4 和 8mg l(-1)的吸附剂，定量了粒子的吸附特性。在最初的 5min 内去除了 90%的 Hg(II)，不到 15min 就达到了平衡，吸附容量高于其他常用的吸附剂。Langmuir 和 Freundlich 等温模型都被应用于等温数据，当吸附剂与吸附质的比例较低时，达到了最大吸附容量。温度和 pH 都对吸附有影响，但当 TF-SCMNPs 用于去除自来水中和瓶装水中的 Hg(II)时，其中含有其他离子，似乎没有干扰。在 3M HCl 溶液中使用硫脲可以成功地解吸 Hg(II)，这不会导致纳米粒子的破坏，并且它们可以在重复吸附测试中重复使用而不会失去其活性。
