Synergism in TiO$_2$ photocatalytic ozonation for the removal of dichloroacetic acid and thiacloprid

Šuligoj, Andraž (author), Kete, Marko (author), Černigoj, Urh (author), Fresno, Fernando (author), Lavrenčič Štangar, Urška (author)

The synergistic effect of the photocatalytic ozonation process (PH-OZ) using the photocatalyst TiO$_2$ is usually attributed to influences of the physicochemical properties of the catalyst, pollutant type, pH, temperature, O$_3$ concentration, and other factors. It is also often claimed that good adsorption on the TiO$_2$ surface is beneficial for the occurrence of synergism. Herein, we tested these assumptions by using five different commercial TiO$_2$ photocatalysts (P25, PC500, PC100, PC10 and JRC-TiO-6) in three advanced oxidation systems - photocatalysis (O$_2$/TiO$_2$/UV), catalytic ozonation (O$_3$/TiO$_2$) and PH-OZ (O$_3$/TiO$_2$/UV) - for the degradation of two pollutants (dichloroacetic acid - DCAA and thiacloprid) simultaneously present in water. The synergistic effect in PH-OZ was much more pronounced in the case of thiacloprid, a molecule with low adsorption on the surface of the catalyst - in contrast to DCAA with stronger adsorption. The faster kinetics of catalytic ozonation (O$_3$/TiO$_2$) correlated with the higher exposed surface area of TiO$_2$ agglomerates, independent of the (lower) BET surfaces of the primary particles. Nevertheless, DCAA mineralization on the TiO$_2$ surface was much faster than thiacloprid degradation in solution. Therefore, we propose that a high BET surface area of the photocatalyst is crucial for fast surface reactions (DCAA mineralization), while good dispersion - the high exposed surface area of the (small) agglomerates - and charge separation play an important role in photocatalytic degradation or PH-OZ of less adsorbed organic pollutants (thiacloprid).

• Language: English
• Keywords: water purification, adsorption, TiO$_2$ agglomerates, neonicotinoids, synergism
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: 9 str.
• Numbering: Vol. 197, art. 110982
• PID: 20.500.12556/RUL-138670
• UDC: 544.3/.4
• ISSN on article: 0013-9351
• DOI: 10.1016/j.envres.2021.110982
• COBISS.SI-ID: 57560067
• Publication date in RUL: 09.08.2022

Record is a part of a journal

• Title: Environmental research. multidisciplinary journal of environmental sciences, ecology, and public health
• Shortened title: Environ. res.
• Publisher: Academic Press
• ISSN: 0013-9351
• COBISS.SI-ID: 3951911

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: fotokataliza, titanov dioksid, sinergija, učinki

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P1-0134
• Name: Kemija za trajnostni razvoj

• Funder: EC - European Commission
• Funding programme: European Social Fund, Operational Program for Human Resources Development