Reaction Process of Perfluorooctanesulfonic Acid (PFOS) Decomposed by DC Plasma Generated in Argon Gas Bubbles
Reaction Process of Perfluorooctanesulfonic Acid (PFOS) Decomposed by DC Plasma Generated in Argon Gas Bubbles
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氩气气泡中产生的直流等离子体分解全氟辛烷磺酸（PFOS）的反应过程
DOI：
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发表时间：
2014
影响因子：
1.5
通讯作者：
K. Yasuoka
中科院分区：
文献类型：
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作者：
K. Tachibana;N. Takeuchi;K. Yasuoka
全氟辛烷磺酸（PFOS：<sub>C8</sub><sub>F17</sub>SO<sub>3</sub> H）是一种具有生物累积性和环境持久性的物质.全氟辛烷磺酸不能通过传统的水处理方法分解;因此，需要一种新的降解方法。全氟辛烷磺酸可以通过气泡中产生的直流等离子体有效降解。由于这一过程尚未得到阐明，我们研究了PFOS降解过程中的副产物和反应过程。用氩气泡中产生的直流等离子体对初始浓度为55.5 mg/L的PFOS水溶液进行600 min的分解，测定了PFOS、全氟羧酸（PFCAs：Cn F2<sub>n +1</sub> COOH，n=1-7）、二氧化碳、一氧化碳和氟离子的浓度，但没有达到碳或氟的质量平衡。<sub></sub>为了检测未知的副产物，分析了处理180分钟的全氟辛烷磺酸水溶液和从反应器释放的气体。在液相中检测<sub>到Cm</sub>HF<sub>2 m</sub> SO<sub>3</sub> H（m=2-8）和<sub>Ci</sub>HF<sub>2 i</sub>COOH（i=2-7），在气相中检测到CHF<sub>3</sub>、<sub>C2</sub>HF<sub>5</sub>和<sub>C2</sub><sub>F6</sub>鉴于这些副产品，有人提出，一些全氟辛烷磺酸会立即热分解为二氧化碳、氟离子等。剩余的PFOS在高能粒子的碰撞下逐渐降解，最终产物包括氟碳化合物气体和氟离子。
Perfluorooctanesulfonic acid (PFOS: C<sub>8</sub>F<sub>17</sub>SO<sub>3</sub>H) is a bioaccumulative and environmentally persistent substance. PFOS cannot be decomposed by conventional water treatments; therefore, a new degradation method is required. PFOS can be efficiently degraded by dc plasma generated in gas bubbles. Since this process has yet to be elucidated, we investigated the by-products and the reaction process during the degradation of PFOS. Aqueous PFOS (initial concentration of 55.5 mg/L) was decomposed by dc plasma generated in argon gas bubbles for 600 min, and the concentrations of PFOS, perfluorocarboxylic acids (PFCAs: C<sub>n</sub>F<sub>2n+1</sub>COOH, n=1-7), carbon dioxides, carbon monoxides, and fluoride ions were measured, but we did not achieve mass balances for carbon or fluorine. To detect the unknown by-products, both aqueous PFOS that was treated for 180 min and the gas released from the reactor were analyzed. C<sub>m</sub>HF<sub>2m</sub>SO<sub>3</sub>H (m=2-8) and C<sub>i</sub>HF<sub>2i</sub> COOH (i=2-7) were detected in the liquid phase, and CHF<sub>3</sub>, C<sub>2</sub>HF<sub>5</sub>, and C<sub>2</sub>F<sub>6</sub> were found in the gas phase. Given these by-products, it has been proposed that some PFOS is immediately thermally decomposed to carbon dioxides, fluoride ions, and hence forth., and the remaining PFOS is gradually degraded by the collisions of high energy particles, leading to the final products that include fluorocarbon gases and fluoride ions.