Procesos fotocatalíticos y de adsorción para la eliminación de arsénico en disoluciones acuosas

Abstract

This work aimed to study the removal of arsenic from aqueous solution by photocatalytic and adsorption processes. The manuscript is organized in five parts. The introductory revision, as being the state of the art of the topic, corresponds to Part 1. Part 2 presents the thesis motivation that accounts for this work. In Part 3, the synthesis of catalysts, procedures for the immobilization of TiO2 , the experimental setups and analytical techniques, and the characterization techniques used to obtain the experimental results are described. Part 4 consists on the report of the experimental results and discussion of arsenic removal from aqueous systems by photocatalytic and adsorption processes using titanium dioxide (TiO2 ) and iron materials in slurry (Chapter 4.1) and immobilized (Chapter 4.2) configuration, and graphitic carbon nitride (g-C3N4 ) in suspension (Chapter 4.3). On Chapter 4.1, it is evaluated the efficacy of commercial catalysts (TiO2 and zero-valent iron or ZVI) and synthesized catalysts (nano-scale ZVI, nZVI, and composites of TiO2 /nZVI with different TiO2 :Fe ratio ).Chapter 4.2 is devoted to the study of photocatalytic activity and reutilization feasibility of immobilized TiO2 over different pH conditions, in the presence or absence of ZVI and nZVI. Chapter 4.3 includes the study of the activity of g-C3N4 and g-C3N4 T500 (exfoliated) for the oxidation of As(III) under UV-LED and visible-LED irradiation and the mechanism of this oxidation. Finally, Part 5 summarizes the main conclusions of this work.