A step forward on NETmix reactor for heterogeneous photocatalysis: Kinetic modeling of As(III) oxidation

• Type: Article in International Scientific Journal
• Date: 2021-08-14

Authors

Vitor Vilar (Author) FEUP; Sara Santos (Author) FEUP; Larissa Paulista (Author) Other; Belisa Marinho (Author) Other; Claudio Passalía (Author) Other; Maria Flores (Author) Other; Marisol Labas (Author) Other; Rodolfo Brandi (Author) Other

Journal

Title: Chemical Engineering Journal

Vol. 405

ISSN: 1385-8947

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 1 Citation

ISI Web of Science

Scopus - 2 Citations

Scientific classification

CORDIS: Technological sciences > Technology > Environmental technology

FOS: Engineering and technology > Environmental engineering

Associated Projects

AIProcMat@N2020 - Advanced Industrial Processes and Materials for a Sustainable North Region of Portugal2020

Other information

Authenticus ID: P-00S-ME0

DOI: 10.1016/j.cej.2020.126612

Abstract (EN): This study focuses on the kinetic modeling of As(III) oxidation by heterogeneous TiO2 photocatalysis, assisted by ultraviolet light emitting diodes, using a static mixer - NETmix reactor - in two different configurations: backside illumination and front-side illumination. First, preliminary experimental assays were performed varying the load of TiO2-P25 and the incident radiation flux for each configuration, and the observed pseudo-first-order kinetic constants were obtained. A model was built based on a mechanistic reaction pathway for As(III) oxidation, taking into account the radiation absorption by the catalytic surface. Three kinetic parameters were estimated considering the solution of the material balance for the existing chemical species and the evaluation of the radiation field inside the reactor by solving the Radiative Transfer Equation. The incident radiation flux was determined at every point on the catalyst surface. It was concluded that the initial reaction rate per unit area is similar in both reactor configurations. However, when compared per unit volume, front-side illumination exhibits twice the reaction rate as the back-side illumination. Moreover, according to the obtained parameters, the front-side configuration showed higher As(V) adsorptivity when compared to the back-side. In addition, the dependence of the reaction rate upon the incident radiation level proved to be the same regardless of the illumination mechanism. Nevertheless, considering that the radiation field is not uniform, the complete expression of the dependence with the local incident radiation flux in the reaction rate equations must be used. The results obtained with the model predictions were contrasted with the experimental data regarding As(III) concentra-tions and showed a good agreement for both reactor configurations.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11