| UV/TiO_2光催化还原Cr(Ⅵ)过程中吸附作用的影响及其消除 |
| 摘要点击 2771 全文点击 1265 投稿时间：2005-03-25 修订日期：2005-06-08 |
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| 中文关键词 二氧化钛 光催化 铬 吸附 |
| 英文关键词 titanium oxide photocatalysis chromium absorption |
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| 中文摘要 |
| 研究了水体中Cr(Ⅵ)离子在UV/TiO2体系中光催化还原过程.结果表明,Cr(Ⅵ)离子UV/TiO2光催化还原过程符合Langmuir-Hinshelwood动力学规律.不存在有机物时,TiO2吸附作用是该反应的前提.pH=1.5～2.5时吸附性能较好,而且pH=1.5～10的初始反应速率同pH值有线性关系.在TiO2表面的竞争吸附能力按PO43->SO42->Cl->NO3-依次减弱.甲酸、甲醛有机物的协同作用可提高Cr(Ⅵ)离子的光催化还原速率和效率,并消除由暗态吸附对反应所起的作用,磷酸根离子极强的竞争吸附能力,使有机物的协同作用减弱. |
| 英文摘要 |
| Reduction of Cr(Ⅵ) in aqueous solution were studied by the UV/TiO2 photo-reduction process.The results show that the photo-reduction of Cr(Ⅵ) ion by UV/TiO2 agrees with Langmuir-Hinshelwood equation well.In absence of organic matters,absorption of TiO2 is the key step for this process,and optimal condition is pH=1.5～2.5.The initial reduction rate correlate with pH value within pH=1.5～10.The ability to competitively absorb to the surface of TiO2 can be ordered by PO43->SO42->Cl->NO3-.Photoreduction rate and efficiency can be enhanced greatly with synergia of formaldehyde or formic acid,meanwhile synergia eliminate the effect of absorption.But synergic effects were reduced with phosphate. |
