Details

Autor(en) / Beteiligte

• Marinho, Belisa A.
• Martín de Vidales, M. J.
• Mazur, Luciana P.
• Paulista, L.
• Cristóvão, Raquel O.
• Mayer, Diego A.
• Loureiro, José M.
• Boaventura, Rui A. R.
• Dias, Madalena M.
• Lopes, José Carlos B.
• Vilar, Vítor J. P.

Titel

Application of a micro-meso-structured reactor (NETmix) to promote photochemical UVC/H2O2 processes–oxidation of As(iii) to As(v)

Ist Teil von

• Photochemical & photobiological sciences, 2018, Vol.17 (9), p.1179-1188

Ort / Verlag

Cham: Springer International Publishing

Erscheinungsjahr

2018

Link zum Volltext

Quelle

SpringerLink (Online service)

Beschreibungen/Notizen

• A micro-meso-structured reactor (NETmix) was used for the first time to promote photochemical UVC/H 2 O 2 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/H 2 O 2 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 H 2 O 2 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 m 3 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 H 2 O 2 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.