摘要:
Based on the higher oxidation potential of OH radicals (2.8 V),the synergetic effect of pulsed dis-charge plasma (PDP)and activated carbon (AC)and the advantages of emission spectroscopic detection,such as easy operation,high accuracy and high sensitivity,the relative emission spectra of the OH radicals genera-ted in the PDP/AC system with oxygen flow were measured by the emission spectroscopic detection technique and the spectral intensity of the OH radicals was used to represent the relative amount of the OH radicals formed in the reaction system.The effect of additive amount of the AC,peak pulse voltage and electrode gap on the relative emission spectrum intensities of OH radicals were investigated to illustrate the crucial factors for the OH radicals formation in the PDP/AC system.In addition,the formation of OH radicals in the two liquid phases of distilled water and acid orange 7 (AO7 )solution in the sole PDP system and the PDP/AC system were investigated to testify the synergetic mechanism of PDP/AC and the oxidization of OH radicals on the or-ganic compounds in the reaction system.The obtained results showed that the catalytic effect of the AC in-creased with the increase of the additive amount of the AC in the PDP system,which led to the increase of the relative emission spectral intensities of the formed OH radicals in the synergistic system;higher peak pulse voltage was in favor of the energy input in the discharge system and then enhanced the formation of OH radi-cals;increase of the electrode gap led to the decrease of energy efficiency in the reaction system and the de-crease of the formed OH radicals in the PDP/AC system;the formation of OH radicals in the PDP/AC system was higher than that in the sole PDP system both in the distilled water and in the AO7 solution;the formation of OH radicals in the distilled water was higher than those in the AO7 solution no matter the reaction system was the sole PDP system or the PDP/AC system.The two results indicated that the AC addition was beneficial to the formation of OH radicals in the PDP system and the OH radicals had an important effect on the organic compounds degradation both in the sole PDP system and in the PDP/AC system.%基于 OH 自由基的强氧化性(2.8 V)及脉冲放电等离子体(pulsed discharge plasma,PDP)与活性炭(activated carbon,AC)联合体系的协同作用,依托于光谱检测技术简单、准确性高、灵敏度高等优点,利用发射光谱技术测量了以 O2作为载气的PDP/AC联合体系中产生的 OH 自由基的相对发射光谱,用以表征体系中 OH 自由基相对生成量的变化。通过考察PDP 水处理体系中不同 AC 添加量、脉冲峰值电压、电极间距对OH 自由基相对发射光谱强度的影响,分析了影响OH 自由基生成量的因素;通过比较,分析去离子水和酸性橙 II(acid orange,AO7)溶液中 OH 自由基发射光谱强度的变化规律,表征了 OH 自由基生成量的变化,以说明PDP/AC的协同作用机理及OH 自由基对有机物的氧化作用。研究结果表明,增加AC的添加量可以增强其在PDP体系中的催化效果,导致 PDP/AC 联合体系中 OH 自由基的相对发射光谱强度的增加;随着脉冲峰值电压的升高,注入PDP体系中的能量增加,从而增加了体系中OH 自由基的产量;电极间距增加导致PDP体系能量效率降低,降低了OH 自由基的产生量;无论是以去离子水还是以AO7溶液为溶液相,PDP/AC联合体系中 OH 自由基的产量均高于其在单独PDP体系中的生成量,且在 PDP/AC联合体系和单独的PDP作用体系中,去离子水中 OH 自由基的相对发射光谱强度均高于其在 AO7溶液中的强度值,这证明了 AC对PDP体系中 OH 自由基生成的协同作用和有机物对 OH 自由基的消耗。