| UV强化草酸络合Fe3+活化过硫酸盐氧化降解苯胺 |
| 摘要点击 2971 全文点击 1052 投稿时间：2018-01-22 修订日期：2018-03-16 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 紫外光 草酸络合铁离子 过硫酸盐 活化 氧化 |
| 英文关键词 ultraviolet light ferric oxalate persulfate activation oxidation |
|
| 中文摘要 |
| 采用UV-草酸络合Fe3+[UV-Fe（C2O4）33-]活化过硫酸钠（PS）氧化降解苯胺，研究了Fe（C2O4）33-浓度，PS浓度，pH对PS活化效率及苯胺氧化降解效果的影响机制.结果表明，Fe（C2O4）33-浓度和pH决定了UV-Fe（C2O4）33-体系中Fe3+向Fe2+的转化过程，并对活化PS氧化降解苯胺产生显著影响.随着Fe（C2O4）33-浓度增加，PS的分解率不断提高，但当浓度高于0.75 mmol·L-1时，草酸根离子（C2O42-）对硫酸根自由基（SO4·-）的竞争以及SO4·-之间的相互淬灭作用降低了苯胺的降解效果，降解速率大小顺序为5 mmol·L-1 < 0.25 mmol·L-1 < 0.5 mmol·L-1 < 1 mmol·L-1 < 0.75 mmol·L-1；中性和碱性条件不利于Fe（C2O4）33-发生光化学反应生成Fe2+，但当初始pH为7和9时，由于PS活化分解过程降低反应体系pH，反应300 min时PS的活化率可分别达到74%和67%，苯胺去除率分别高达91%和97%，均高于初始pH为酸性条件下的结果；苯胺降解率随初始PS浓度增加而增大，当PS浓度大于10 mmol·L-1时，苯胺降解过程由二级反应变为准一级反应，但此时过量的PS因与SO4·-发生反应而显著降低PS用于氧化降解苯胺的利用率. |
| 英文摘要 |
| Oxidative degradation of aniline by Sodium Persulfate (PS) activated with UV-ferric oxalate[UV-Fe(C2O4)33-] was studied. The effects of Fe(C2O4)33- concentration, PS concentration, and pH on PS activation and aniline degradation were investigated. Results showed that Fe(C2O4)33- concentration and pH determined the reduction process of Fe3+ into Fe2+, which had significant effects on the oxidative degradation of aniline by PS. With an increase in Fe(C2O4)33- concentration, PS decomposition increased; however, when concentrations were>0.75 mmol·L-1, aniline degradation efficiency decreased due to competition with oxalate ions (C2O42-) for SO4·-. Aniline degradation efficiency in processes with different initial Fe(C2O4)33- concentrations followed the sequence:5 mmol·L-1 < 0.25 mmol·L-1 < 0.5 mmol·L-1 < 1 mmol·L-1 < 0.75 mmol·L-1. Neutral and alkaline conditions were not conducive to Fe2+ formation via photochemical reaction. However, with initial pH values of 7 and 9, PS activation efficiency reached 74% and 67% respectively after 300 min due to pH decline during the reaction; aniline removal efficiency was as high as 91% and 97%, respectively, higher than under initial acidic conditions. Furthermore, increased PS concentration was conducive to improvement of aniline degradation efficiency, but when PS concentration was>10 mmol·L-1, the aniline degradation process followed the pseudo first-order reaction kinetics model instead of the second-order reaction kinetics model. PS efficiency for aniline degradation decreased significantly due to the reaction between excessive PS and sulfate radicals. |
|
|
|
