| 李炳智,朱江.超声活化过硫酸盐氧化降解水溶液中的全氟辛烷磺酸盐[J].农业环境科学学报,2019,38(4):912-920. |
| 超声活化过硫酸盐氧化降解水溶液中的全氟辛烷磺酸盐 |
| Oxidative degradation of perfluorooctane sulfonate by a sono-activated persulfate system in an aqueous solution |
| 投稿时间：2018-05-15 |
| DOI：10.11654/jaes.2018-0638 |
| 中文关键词: 全氟辛烷磺酸盐 超声活化 过硫酸盐 动力学特征 降解机理 |
| 英文关键词: perfluorooctane sulfonate(PFOS) sono-activated persulfate kinetic characteristics degradation mechanism |
| 基金项目:国家自然科学基金项目（41303095）；上海市自然科学基金项目（17ZR1424000，16ZR1429700）；上海市环科院青创基金项目（CX201601） |
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| 摘要点击次数: 2065 |
| 全文下载次数: 2052 |
| 中文摘要: |
| 针对全氟辛烷磺酸盐（PFOS）去除，构建了超声活化过硫酸盐氧化体系。考察了体系中超声频率、过硫酸盐浓度、溶液初始pH值和空化气体等因素对PFOS降解速率的影响，并对PFOS降解过程产生的自由基及其降解中间产物进行了捕捉和鉴定。结果表明：在30℃、pH值7.0、过硫酸盐浓度0.93 mmol·L-1、超声频率400 kHz、功率100 W和超声密度2.67 W·cm-2条件下，18.58μmol·L-1的PFOS经过8 h反应，降解率达到99.5%。超声活化过硫酸盐体系表现出显著的协同效应，PFOS降解速率比单独超声和单独过硫酸盐体系降解速率之和提高4.77倍，其表观准一级反应动力学常数在实验范围内随超声频率增加而增大，随过硫酸盐浓度增加先增后减，随溶液初始pH值增加而减小，四种空化气体中以氩气的降解效果为最佳；电子自旋捕捉试验表明，硫酸根自由基和羟基自由基参与了PFOS的降解。根据超高效液相色谱-质谱（UPLC-MS）分析得到的七种降解产物，给出了PFOS在该体系中可能的降解途径。 |
| 英文摘要: |
| A sono-activated persulfate oxidative system was built to remove typical perfluorooctane sulfonate (PFOS). The effects of ultrasonic frequency, persulfate concentration, initial pH value, and the cavitation gas of the system on PFOS degradation rates were studied. The generated radicals and degradation intermediates of PFOS in this process were also captured and identified. The results indicated that 99.5% of 18.58 μmol·L-1 PFOS was degraded under a reaction temperature of 30℃, pH of 7.0, persulfate concentration of 0.93 mmol·L-1, ultrasonic frequency of 400 kHz, power of 100 W, ultrasonic density of 2.67 W·cm-2, and reaction time of 8 h. The PFOS degradation rate of the sono-activated persulfate system was 4.77 times higher than that of the single ultrasound and persulfate systems, which suggested a notable synergic effect. Further investigation also demonstrated that the apparent pseudo-first-order rate constants tended to increase with both the increase in ultrasonic frequency from 20 to 400 kHz and persulfate concentration from 18.58 to 930.0 μmol·L-1, but decreased with both the increase in the initial pH values from 3.00 to 11.03 and with the order of cavitation gases as argon, oxygen, nitrogen, and air. Electron spin trapping experiments showed that sulfate and hydroxyl radicals were involved in PFOS degradation. According to the seven types of degradation intermediates detected by UPLC-MS analysis, a tentative PFOS degradation pathway was proposed. |
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