Co-existing substances (substances not targeted for degradation) can negatively affect wastewater treatment process performance. Here, we quantitatively evaluated the effects of propanal, a common co-existing substance, on the degradation of the azo-dye Orange II, a common pollutant, by the Fenton process to provide data for the development of measures to reduce the effects of co-existing substances on this wastewater treatment process. Inhibition rate (IR; ratio of the reaction rate constants obtained in the absence and presence of propanal) was calculated to examine the effects of propanal on the degradation of Orange II. The IRs for the Fenton process in the first phase and the second phase were 1.6 and 4.2, respectively. However, addition of ultraviolet irradiation to the Fenton process (i.e., the photo-Fenton process) resulted in a comparable IR for the first phase but a markedly lower IR for the second phase. We attributed this to the improvement of the photo-reduction reaction rate due to complexation of propanal with ferric ions, which compensated for the scavenger effects (the trapping of OH radicals) of propanal. Thus, ultraviolet irradiation reduced the inhibitory effects of propanal on the degradation of Orange II by the Fenton process.

中文翻译：

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通过紫外线辐照减轻共存物质对Fenton过程的抑制作用。

共存物质（非降解物质）可能会对废水处理过程的性能产生负面影响。在这里，我们通过芬顿法定量评估了丙醛（一种常见的共存物质）对偶氮染料橙II（一种常见污染物）的降解的影响，从而为开发减少钴的影响的措施提供了数据。废水处理过程中存在的物质。计算抑制率（IR；在不存在和存在丙醛的情况下获得的反应速率常数的比率），以检查丙醛对Orange II降解的影响。Fenton工艺在第一阶段和第二阶段的IR分别为1.6和4.2。但是，在Fenton工艺中添加紫外线照射（即，（光芬顿法）导致第一阶段的IR相当，而第二阶段的IR则明显降低。我们将其归因于由于丙醛与三价铁离子络合而提高了光还原反应速率，从而补偿了丙醛的清除作用（捕获OH自由基）。因此，紫外线照射降低了丙醛对通过芬顿法降解橙II的抑制作用。