| Mg/Al水滑石微波共沉淀法合成及其对BrO3-吸附性能的研究 |
| 摘要点击 2676 全文点击 1398 投稿时间：2013-08-01 修订日期：2013-10-23 |
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| 中文关键词 Mg/Al水滑石 BrO3- 吸附动力学 等温吸附方程 Thomas模型 |
| 英文关键词 Mg/Al layered double hydroxides bromate adsorption kinetics isotherm equation Thomas model |
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| 中文摘要 |
| 采用微波共沉淀法和普通共沉淀法合成了Mg/Al水滑石，分别记做Mg/Al LDHs-MW和Mg/Al LDHs-H.通过XRD、BET、SEM和FT-IR等手段对Mg/Al水滑石结构进行表征. 结果表明，微波共沉淀法合成的水滑石结晶度较好、粒径较小，孔径为41.13 nm，粒径为427.08 nm.序批次实验考察了投加量、溶液pH值和再生次数等因素对溴酸根（BrO3-）吸附性能的影响.结果表明，Mg/Al水滑石吸附BrO3-过程可用准二级动力学模型描述，吸附规律符合Langmuir等温吸附方程.对比Mg/Al LDHs-H的饱和吸附量（q0=288.74 μg·g-1），Mg/Al LDHs-MW对BrO3-具有更强的吸附能力（q0=321.26 μg·g-1）.在动态连续流条件下，利用Thomas模型模拟3组Mg/Al LDHs-MW对BrO3-的动态吸附数据，拟合得到吸附柱最大的吸附容量为288.81 μg·g-1.当填料高度为10 cm，进水浓度为800 μg·L-1，进水流量为4.0 mL·min-1时，模型的相关性系数为0.92，表明实验数据与模拟穿透曲线吻合. |
| 英文摘要 |
| In this paper, Mg/Al layered double hydroxides (Mg/Al LDHs) were prepared by the microwave-assisted co-precipitation method and the conventional co-precipitation method. The samples were labeled as Mg/Al LDHs-MW and Mg/Al LDHs-H, respectively. Mg/Al LDHs were characterized by X-ray diffractometer (XRD), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). The results showed that the application of microwave in the preparation process promoted the formation of smaller pore diameter and higher crystallinity particles. The pore size and particle size of Mg/Al LDHs-MW were 41.13 nm and 427.08 nm, respectively. Batch experiments were investigated to evaluate the effect of dosage, initial pH and regeneration frequencies for bromate removal. The conclusion showed that the process of bromate removal on Mg/Al LDHs could be described by the pseudo-second kinetic model. The Langmuir isotherm well described the experimental data, and the Mg/Al LDHs-MW has a stronger adsorption capacity while the maximum adsorption capacity (q0) of Mg/Al LDHs-MW for bromate was 321.26 μg·g-1 which was larger than the q0(288.74 μg·g-1) of Mg/Al LDHs-H. For the continuous fixed-bed column, model simulations using the Thomas model showed that the experimental data obtained at three different columns packed with Mg/Al LDHs-MW were able to predict breakthrough curves. Simulating the maximum adsorption capacity of adsorption column for bromate removal was 288.81 μg·g-1. When the bed depth was 10 cm, inlet concentration was 800 μg·L-1and flow rate was 4.0 mL·min-1, the correlation coefficient of model was 0.92, indicating that the experimental data was described well by the Thomas model. |
