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

• Type: Article in International Scientific Journal
• Date: 2018-07-13

Authors

Belisa A. Marinho (Author) FEUP; M. J. Martin de Vidales (Author) FEUP; Luciana P. Mazur (Author) FEUP; L. Paulista (Author) FEUP; Raquel O. Cristóvão (Author) FEUP; Diego A. Mayer (Author) Other; José M. Loureiro (Author) FEUP; Rui A. R. Boaventura (Author) FEUP; Madalena M. Dias (Author) FEUP; José Carlos B. Lopes (Author) FEUP; Vítor J. P. Vilar (Author) FEUP

Journal

Title: Photochemical & Photobiological Sciences

Vol. 17

Pages: 1179-1188

ISSN: 1474-905X

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 3 Citations

Scientific classification

CORDIS: Technological sciences > Engineering > Chemical engineering

FOS: Engineering and technology > Chemical engineering

Associated Projects

LSRE-LCM - Laboratório de Processos de Separação e Reação - Laboratório de Catálise e Materiais

Other information

Authenticus ID: P-00P-N65

DOI: 10.1039/c8pp00006a

Abstract (EN): 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 x 10(-2) mM) was achieved in 15 min with an absorbed photon flux density of 1.9 x 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 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10