| 硫氰酸根在粒状镁铝复合氧化物上的吸附性能 |
| 摘要点击 2255 全文点击 875 投稿时间：2011-11-22 修订日期：2012-01-14 |
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| 中文关键词 镁铝复合氧化物 粒状 硫氰酸根 吸附 穿透曲线 |
| 英文关键词 Mg/Al mixed oxides granular thiocyanate anion adsorption breakthrough curve |
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| 中文摘要 |
| 以镁铝水滑石(Mg/Al-LDH)为前驱物制备了粒状镁铝复合氧化物(G-Mg3.3AlO4.8),采用BET、XRD、SEM和FT-IR方法对其结构进行了表征,考察了这种新材料对硫氰酸根(SCN-)的吸附性能. G-Mg3.3AlO4.8的比表面积和平均孔径分别为269.4 m2·g-1和13.25 nm,成型造粒保留了层状结构且无新相生成. Freundlich等温式和准二级动力学方程能很好地描述SCN-在G-Mg3.3AlO4.8上的静态吸附过程,25℃初始浓度为500 mg·L-1时静态吸附量可达165.8 mg·g-1; Yoon-Nelson模型能很好地预测SCN-在G-Mg3.3AlO4.8上的穿透曲线,初始浓度100 mg·L-1、流速5 mL·min-1、床层高度10 cm和pH=6时穿透点吸附量可达50.73 mg·g-1,重复使用4次对SCN-的脱除率均保持在98%以上,是一种可重复利用的高效吸附剂. |
| 英文摘要 |
| Granular Mg/Al mixed oxides (G-Mg3.3AlO4.8) was successfully synthesized by using Mg/Al layered double hydroxide (Mg/Al-LDH) as the precursor. Its structure was characterized by analytical methods of BET, XRD, SEM and FT-IR. Adsorption properties of thiocyanate anion (SCN-) on this new material were also investigated. Specific surface area and average pore width of G-Mg3.3AlO4.8 are 269.4 m2·g-1 and 13.25 nm respectively. Molding and granulation retains the layer structure and generates no new phase. Freundlich isotherm equation and pseudo-second-order kinetic equation can describe the static adsorption process precisely and adsorption capacity reaches 165.8 mg·g-1 at 25℃ and 500 mg·L-1. Yoon-Nelson model can predict the breakthrough curves of SCN-on G-Mg3.3AlO4.8 precisely. The breakthrough adsorption capacity reaches 50.73 mg·g-1 under the conditions with initial concentration is 100 mg·L-1, flow rate is 5 mL·min-1, bed layer altitude is 10 cm and initial pH is 6. The removal rates of SCN- are all above 98% after reusing four times. Consequently, G-Mg3.3AlO4.8is a reusable and high-efficient adsorbent. |
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