Enhancement of Iron-Based Photo-Driven Processes by the Presence of Catechol Moieties

• Main Authors: Javier Moreno-Andrés, Iván Vallés, Paula García-Negueroles, Lucas Santos-Juanes, Antonio Arques
• Format: Article
• Language: English
• Published: MDPI AG 2021-03-01
• Series: Catalysts
• Subjects: phenolic moieties; photo-Fenton; persulfate; emerging contaminants; Fe-binding ligands; iron chelates
• Online Access: https://www.mdpi.com/2073-4344/11/3/372

Photo-induced Advanced Oxidation Processes (AOPs) using H₂O₂ or S₂O₈²⁻ as radical precursors were assessed for the abatement of six different contaminants of emerging concern (CECs). In order to increase the efficiency of these AOPs at a wider pH range, the catechol organic functional compound was studied as a potential assistant in photo-driven iron-based processes. Different salinity regimes were also studied (in terms of Cl⁻ concentration), namely low salt water (1 g·L⁻¹) or a salt–water (30 g·L⁻¹) matrix. Results obtained revealed that the presence of catechol could efficiently assist the photo-Fenton system and partly promote the photo-induced S₂O₈²⁻ system, which was highly dependent on salinity. Regarding the behavior of individual CECs, the photo-Fenton reaction was able to enhance the degradation of all six CECs, meanwhile the S₂O₈²⁻-based process showed a moderate enhancement for acetaminophen, amoxicillin or clofibric acid. Finally, a response-surface methodology was employed to determine the effect of pH and catechol concentration on the different photo-driven processes. Catechol was removed during the degradation process. According to the results obtained, the presence of catechol in organic macromolecules can bring some advantages in water treatment for either freshwater (wastewater) or seawater (maritime or aquaculture industry).