Functionalized mesoporous silicas SBA-15 for heterogeneous photocatalysis towards CECs removal from secondary urban wastewater

Bruna Castanheira; Larissa Otubo; Cristiano L P Oliveira; Rosa Montes; José Benito Quintana; Rosario Rodil; Sergio Brochsztain; Vítor J P Vilar; Antonio Carlos S C Teixeira

doi:10.1016/j.chemosphere.2021.132023

Functionalized mesoporous silicas SBA-15 for heterogeneous photocatalysis towards CECs removal from secondary urban wastewater

Chemosphere. 2022 Jan;287(Pt 1):132023. doi: 10.1016/j.chemosphere.2021.132023. Epub 2021 Aug 24.

Authors

Bruna Castanheira¹, Larissa Otubo², Cristiano L P Oliveira³, Rosa Montes⁴, José Benito Quintana⁴, Rosario Rodil⁴, Sergio Brochsztain⁵, Vítor J P Vilar⁶, Antonio Carlos S C Teixeira⁷

Affiliations

¹ Research Group in Advanced Oxidation Processes (AdOx), Chemical Systems Engineering Center, Department of Chemical Engineering, Escola Politécnica, University of São Paulo, Av. Prof. Luciano Gualberto, tr. 3, 380, São Paulo, SP, Brazil.
² Nuclear and Energy Research Institute (IPEN), Av. Prof. Lineu Prestes, 2242, 05508-000, São Paulo, SP, Brazil.
³ Institute of Physics, University of São Paulo, Rua do Matão 1371, 05508-090, São Paulo, SP, Brazil.
⁴ Department of Analytical Chemistry, Nutrition and Food Sciences, Institute of Research on Chemical and Biological Analysis (IAQBUS), Universidade de Santiago de Compostela, Constantino Candeira S/N, 15782, Santiago de Compostela, Spain.
⁵ Federal University of ABC, Av. dos Estados, 5001, 09210-580, Santo André, SP, Brazil.
⁶ Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials (LSRE-LCM), Department of Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal. Electronic address: vilar@fe.up.pt.
⁷ Research Group in Advanced Oxidation Processes (AdOx), Chemical Systems Engineering Center, Department of Chemical Engineering, Escola Politécnica, University of São Paulo, Av. Prof. Luciano Gualberto, tr. 3, 380, São Paulo, SP, Brazil. Electronic address: acscteix@usp.br.

PMID: 34461335
DOI: 10.1016/j.chemosphere.2021.132023

Abstract

The photocatalytic activity of TiO₂ nanoparticles (NPs) supported on mesoporous silica SBA-15 (TiO₂/SBA-15) was evaluated for the photodegradation of sulfadiazine (SDZ), as target contaminant of emerging concern (CEC), using either pure water solutions (PW) or a real secondary urban wastewater (UWW) spiked with SDZ. For this purpose, TiO₂/SBA-15 samples with 10, 20 and 30% TiO₂ (w/w) were prepared by the sol-gel post synthetic method on pre-formed SBA-15, using titanium (IV) isopropoxide as a precursor. The TiO₂/SBA-15 materials were characterized by HRTEM, SAXS and XRD, nitrogen adsorption isotherms and UV-vis diffuse reflectance spectroscopy. TiO₂ NPs were shown to be attached onto the external surface, decorating the SBA-15 particles. The TiO₂/SBA-15 catalysts were active in SDZ photodegradation using the annular FluHelik photoreactor, when irradiated with UVA light. The 30% TiO₂/SBA-15 sample presented the best performance in optimization tests performed using PW, and it was further used for the tests with UWW. The photocatalytic activity of 30% TiO₂/SBA-15 was higher (56% SDZ degradation) than that of standard TiO₂-P25 (32% SDZ degradation) in the removal of SDZ spiked in the UWW ([SDZ] = 2 mg L^-1). The photodegradation of SDZ with 30% TiO₂/SBA-15 eached 90% for UWW spiked with a lower SDZ concentration ([SDZ] = 40 μg L^-1). Aside of SDZ, a suit of 65 other CECs were also identified in the UWW sample using LC-MS spectrometry. A fast-screening test showed the heterogeneous photocatalytic system was able to remove most of the detected CECs from UWW, by either adsorption and/or photocatalysis.

Keywords: Advanced oxidation processes; FluHelik photoreactor; Mesoporous silicas; Photocatalysis; Sulfadiazine.

MeSH terms

Scattering, Small Angle
Silicon Dioxide*
Wastewater*
X-Ray Diffraction

Substances

SBA-15
Waste Water
Silicon Dioxide