【摘要】 采用射频放电等离子体对水中六价铬（Cr（Ⅵ））进行还原研究,用高速相机观察了放电过程中等离子体宏观形貌的变化,用光谱仪检测了放电产生的自由基种类,并考察了入射功率、初始pH,Cr（Ⅵ）初始浓度以及羟基自由基（·OH）清除剂对Cr（Ⅵ）还原的影响。结果表明:等离子体形貌在宏观上呈现周期性变化;放电产生了·OH和氢原子（·H）。降低溶液的pH,增加放电的入射功率以及加入·OH清除剂均有利于Cr（Ⅵ）的还原;·H和次级产物过氧化氢（H₂O₂）是Cr（Ⅵ）还原的主要活性物质;射频放电的能量效率高于光催化,与辉光放电和电晕放电相近。利用射频放电还原水中Cr（Ⅵ）是一种高效、简易的水处理技术。更多还原

【Abstract】 In this study, the radio frequency discharge(RFD) plasma was used to reduce the hexavalent chromium(Cr(Ⅵ)) in wastewater. The macroscopic morphology of the plasma was observed with a high speed camera and the free radicals generated during the discharge were analyzed with an emission spectrometer. The effects of input power, initial pH, initial concentration and hydroxyl radical(·OH) scavenger on Cr(Ⅵ) reduction were examined. The results showed that a periodic macroscopic change occurred on the plasma, ·OH and atomic hydrogen(·H) were formed by the discharge. These two active radicals could lead to pH decrease and input power increase. The ·OH scavenger addition was beneficial to Cr(Ⅵ) reduction. The formed ·H and hydrogen peroxide were the main active species for Cr(Ⅵ) reduction. At the initial pH 2.0, Cr(Ⅵ) removal could reach 99.52% with 30 min discharge treatment. The energy efficiency of RFD is higher than that of photocatalysis, and is comparable to those of glow discharge or corona discharge. The results of Cr(Ⅵ) reduction by RFD indicate it is a high efficient and easy operational wastewater treatment technology, could provide a theoretical basis for Cr(Ⅵ) wastewater treatment.更多还原