The oxidation of methyl orange (MO) under the influence of radiation from spark discharge plasma in air and a low-pressure mercury lamp is studied. Two modes of sample processing are compared: the action of radiation on an aqueous solution of MO (mode 1, direct action) and the action of radiation on water, after which the water is mixed with a solution of MO (mode 2, indirect action). The radiation energy of the mercury lamp is ten times greater than the energy of radiation from spark discharge, but the yield of MO oxidation under the action of the mercury lamp is 100 times lesser than the yield under the action of spark discharge radiation. This is due to the difference in the spectrum of radiation and the operating regime (continuous and pulsed). The yields of MO oxidation under the action of spark discharge plasma radiation for modes 1 and 2 are the same and amount to 1.2–1.3 1/(100 eV). This means that active species are first produced in water and then interact with the dissolved substance, indirect mechanism takes place. Under the action of radiation from a mercury lamp, the oxidation yield in mode 2 is zero within the limits of experimental errors, direct mechanism takes place.

中文翻译：

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火花放电等离子体和紫外灯辐射对水和甲基橙水溶液的直接和间接影响的比较

研究了在空气中火花放电等离子体和低压汞灯辐射影响下甲基橙（MO）的氧化。比较了两种样品处理模式：辐射对 MO 水溶液的作用（模式 1，直接作用）和辐射对水的作用，然后将水与 MO 溶液混合（模式 2，间接作用） ）。汞灯的辐射能量比火花放电辐射的能量大十倍，但汞灯作用下的MO氧化产率比火花放电辐射作用下的产率小100倍。这是由于辐射光谱和操作方式（连续和脉冲）的不同造成的。在火花放电等离子体辐射作用下，模式 1 和模式 2 的 MO 氧化产率相同，为 1.2–1.3 1/(100 eV)。这意味着活性物质首先在水中产生，然后与溶解物质相互作用，发生间接机制。在汞灯辐射作用下，模式2的氧化产率在实验误差范围内为零，发生直接机理。