中文摘要：

研究了在空气、O2和N2气氛下滑动弧等离子体在纯水中放电的发射光谱，并以甲基紫为目标污染物，分析了在不同气氛下甲基紫的降解率以及降解产物．结果表明，在三种气氛下，OH自由基均是在放电过程中产生的最主要自由基；在空气和O2气氛下，甲基紫降解20min后的降解率达到99％以上，高于在N2气氛下甲基紫的降解率．根据傅里叶红外光谱（FTIP）及气相色谱-质谱联用仪（GC—MS）的中间产物分析结果，在三种气氛下甲基紫分子中心碳原子的共轭结构在自由基作用下断裂，染料降解脱色，染料中间体在自由基作用下进一步降解、开环，直到生成CO2和H2O．

英文摘要：

The emission spectrum of gas-liquid gliding arc discharge in distilled water under different carrier gases such as air, oxygen, nitrogen atmosphere were studied, and the degradation rate and intermediate products of methyl violet were investigated. The results showed that OH radicals play a significant role in the wastewater treatment under the three carrier gases; and the degradation rates of methyl violet under air and oxygen atmosphere achieved over 99%o after 20 min, which was higher than that under nitrogen atmosphere. The intermediate product analysis of Fourier transform infrared （FTIR） spectroscopy and gas chromatography-mass spectrometry （GC-MS） shows that OH radicals attack the carbon atom that situates in the center of methyl violet molecule, and the conjugating structure of methyl violet is destroyed, thus the dye is degraded and decolored; then the intermediates are further oxidated and the ring is cleaved, and CO2 and H2O are generated at last.