A micro-meso-structured reactor (NETmix) was used for the first time to promote photochemical UVC/H₂O₂ processes. The NETmix photoreactor consists of a network of chambers and channels, where the liquid flows, sealed with a quartz slab with high UVC transparency. Due to the small size of channels and chambers, the NETmix presents a uniform irradiance through the entire reactor depth, short molecular diffusion distances and large specific interfacial areas, maximizing the pollutant/oxidant contact. In this study, the NETmix photoreactor was evaluated for As(III) oxidation to As(V) using a photochemical UVC/H₂O₂ system. The effect of the UVC lamp power (4, 6 or 11 W), the number of UVC lamps (2 or 3 lamps) and the UVC lamp layout (parallel or perpendicular to the flow direction) was evaluated, in order to ensure uniform irradiation of the entire reaction mixture. The optimum H₂O₂ concentration for each light distribution system was also evaluated. At the best configuration, 3 lamps of 11 W positioned parallel to the flow direction, total As(III) oxidation ([As(III)]₀ = 1.33 × 10⁻² mM) was achieved in 15 min with an absorbed photon flux density of 1.9 × 10⁻¹ einstein per m³ per s. Significant differences were highlighted between the photon flux actually received in the photoreactor and the radiant power emitted by the lamp. A kinetic model able to represent the As(III) oxidation employing UVC radiation and H₂O₂ in a micro-meso-structured reactor was presented. The photochemical space time yield (PSTY) values obtained for the micro-meso-structured reactor are higher than for conventional batch reactors, showing that the NETmix technology can be a good solution for application in photochemical processes.

中文翻译：

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应用微介孔结构反应器（NETmix）促进光化学UVC / H ₂ O ₂过程–从As（iii）氧化为As（v）†

首次使用微介孔结构反应器（NETmix）来促进光化学UVC / H ₂ O ₂工艺。NETmix光反应器由腔室和通道网络组成，液体在其中流动，并用具有高UVC透明性的石英平板密封。由于通道和腔室的尺寸较小，因此NETmix在整个反应器深度，较短的分子扩散距离和较大的比界面区域内呈现均匀的辐照度，从而最大程度地实现了污染物/氧化剂的接触。在这项研究中，使用光化学UVC / H ₂ O ₂评价了NETmix光反应器将As（III）氧化为As（V）的能力。系统。为了确保均匀照射，评估了UVC灯功率（4、6或11 W），UVC灯的数量（2或3灯）和UVC灯布局（平行或垂直于流向）的影响。整个反应混合物。还评估了每个配光系统的最佳H ₂ O ₂浓度。在最佳配置下，在15分钟内以吸收的光子通量密度实现了3盏11 W平行于流向的灯，总As（III）氧化（[As（III）] ₀ = 1.33×10 ^-2 mM）每m ³ 1.9×10 ^-1爱因斯坦每秒 在光反应器中实际接收到的光子通量与灯发出的辐射功率之间的显着差异被突出显示。提出了一种动力学模型，该动力学模型能够表示在微介孔结构反应器中使用UVC辐射和H ₂ O ₂氧化As（III）的过程。微介孔结构反应器获得的光化学时空产率（PSTY）值高于常规间歇反应器，表明NETmix技术可以很好地应用于光化学过程。