Decomposition of Persistent Organics in Water Using a Gas-Liquid Two-Phase Flow Plasma Reactor
Decomposition of Persistent Organics in Water Using a Gas-Liquid Two-Phase Flow Plasma Reactor
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DOI：
10.1109/tps.2009.2017124
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发表时间：
2009-06-01
影响因子：
1.5
通讯作者：
Yasuoka, Koichi
中科院分区：
文献类型：
--
作者：
Katayama, Hiroshi;Honma, Hiroyuki;Yasuoka, Koichi
研究了惰性气体泡内脉冲介质阻挡放电（DBDs）降解水中持久性有机物的效果。两个玻璃管同轴安装，金属电极连接在管的内表面和外表面，作为介电屏障。10-ppm乙酸溶液填充管之间的差距并充当持久性有机材料。通过鼓泡器将流量受控的惰性气体如氩气和氖进料到溶液中并形成气液两相流。重复频率高达10 kHz的快速上升脉冲电压在气泡内部产生脉冲DBD，该气泡桥接管之间的1 mm间隙。用高速摄像机捕获气泡图像，而增强的电荷耦合器件相机在5 ns的曝光时间捕获时间放电图像。通过乙酸浓度的减少量来测量分解速率和能量效率;发现使用氖获得更高的效率。从氖放电的羟基（OH）自由基发射强度低于从氩放电。激光诱导荧光测量表明，在氖放电实验中，使用针-平面型电极的基态OH自由基的数密度较高。基态的OH自由基对乙酸的分解更重要。
Pulsed dielectric barrier discharges (DBDs) generated inside inert gas bubbles were studied to decompose persistent organic materials in water. Two glass tubes were coaxially mounted, and metal electrodes were attached at the inner and outer surfaces of the tubes that acted as dielectric barriers. A 10-ppm acetic acid solution filled the gap between the tubes and acted as the persistent organic material. Flow-controlled inert gases, such as argon and neon, were fed through a bubbler into the solution and formed a gas-liquid two-phase flow. Fast-rising pulsed voltages at repetitive frequencies up to 10 kHz generated pulsed DBDs inside the gas bubbles that bridged the 1-mm gap between the tubes. Bubble images were captured with a high-speed video camera, while an intensified charge-coupled device camera captured temporal discharge images at an exposure time of 5 ns. The decomposition rate and energy efficiency were measured by the decreased amount of acetic acid concentration; it was found that higher efficiency was obtained using neon gas. The hydroxyl (OH) radical emission intensity from the neon discharge was lower than that from an argon discharge. Laser-induced fluorescence measurements revealed that the number density of OH radicals in the ground state was higher in neon discharge experiments using a pin-plane-type electrode. The OH radicals in the ground state are more important for the decomposition of acetic acid.