| 锰氧化物改性硅藻土对苯胺的去除动力学与机制 |
| 摘要点击 2975 全文点击 1685 投稿时间：2015-01-30 修订日期：2015-03-30 |
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| 中文关键词 改性硅藻土 锰氧化物 苯胺 动力学 去除机制 |
| 英文关键词 modified diatomite manganese oxides aniline kinetics removal mechanism |
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| 中文摘要 |
| 硅藻土经焙烧并用高锰酸钾和盐酸改性处理,制备出一种新型的改性硅藻土(Mn-D). 考察了Mn-D制备过程中焙烧温度和改性比例(ρ)对其去除苯胺性能的影响,探讨了Mn-D对苯胺的去除动力学行为和去除机制. 结果表明,当焙烧温度为450℃、ρ为1.6和负载δ-MnO2量为0.82 g·g-1时,Mn-D对苯胺有最佳去除效率且伴有Mn2+的释放,10 min内可达饱和吸附量的80%. 在酸性条件下,准二级方程能够较准确地描述Mn-D对苯胺的去除动力学行为,且其过程主要由颗粒内扩散过程控制; Freundlich方程能较好地拟合苯胺在Mn-D上的等温吸附过程; 通过气相色谱-质谱联用仪对反应产物进行检测分析,发现偶氮苯为主要中间产物,并提出了苯胺的可能去除途径. |
| 英文摘要 |
| A novel rapid green one-step method was developed for the preparation of manganese modified diatomite (Mn-D) by treating roasted diatomite with an acidic permanganate solution. The effects of calcination temperature and mass ratio of KMnO4 and diatomite (ρ)on aniline removal efficiency of Mn-D were investigated. The removal kinetics and mechanism of aniline by Mn-D were also discussed. The results showed that when the optimal calcination temperature was 450℃, ρ was 1.6, and the loading amounts of δ-MnO2 was 0.82 g·g-1, Mn-D had a great performance for aniline removal, and more than 80% of aniline was adsorbed within 10 minutes, accompanied with the release of Mn2+. In acidic conditions, the adsorption process on Mn-D followed pseudo-second-order and was mainly controlled by intra-particle diffusion. The best fitting of the experimental adsorption data was given by the Freundlich equation. Gas chromatograph-mass spectrometer was applied to identify the reaction intermediates at different times, and azobenzene was found to be the main reaction intermediate in the degradation system. Based on the above observations, the possible degradation pathway of aniline by Mn-D was proposed. |
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