Carbon nitride-PVDF photocatalytic membranes for visible-light degradation of venlafaxine as emerging water micropollutant

• Type: Article in International Scientific Journal
• Date: 2023

Authors

Valenzuela, L (Author) Other; Pedrosa, M (Author) FEUP; Bahamonde, A (Author) Other; Rosal, R (Author) Other; Torres-Pinto, A (Author) Other; Claudia G Silva (Author) FEUP; Faria, JL (Author) Other; Silva, Adrian (Author) FEUP

Journal

Title: Catalysis Today

Vol. 418

ISSN: 0920-5861

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

Scopus

Associated Projects

Healthy Waters - Healthy Waters - Identification, Elimination, Social Awareness and Education of Water Chemical and Biological Micropollutants with Health and Environmental Implications

Other information

Authenticus ID: P-00Y-66P

DOI: 10.1016/j.cattod.2023.114042

Abstract (EN): Metal-free carbon nitride-based membranes were prepared by embedding bulk or exfoliated graphitic carbon nitride (g-C3N4) photocatalysts in a polyvinylidene fluoride (PVDF) matrix. Supported membranes were also fabricated by immobilising these photocatalysts on a polytetrafluoroethylene (PTFE) substrate. The membranes were tested for venlafaxine (VFX) degradation at a feed concentration of 250 mu g L-1 under continuous flow mode operation and using a visible-light emitting diode (LED) as energy source. The reduction of the (002) diffraction peak and the increased intensity of the infrared absorption bands confirmed that the exfoliation process decreased the number of aligned g-C3N4 layers, with a more ordered packing of tri-s-triazine units. Additionally, the small particle size (around 745 and 257 nm for bulk and exfoliated g-C3N4, respectively) and the presence of terminal amino groups in the catalysts allowed for homogeneous dispersion in the PVDF matrix. Despite their different surface roughness and cross-sectional microstructure, all the fabricated membranes exhibited similar photocatalytic filtration performance for VFX degradation, resulting in conversions above 95% after 5 h of irradiation (418 nm with an irradiance of 11.2 W m- 2) and keeping the VFX concentration in the effluent negligible up to 48 h of continuous operation (mass removal rate of about 6 mg m- 2 h-1). In a more complex water matrix (i.e., surface water), the photocatalytic filtration process led to 50% VFX removal (or 3 mg m- 2 h-1) at the steady state. Moreover, the permeate flux remained at about 25 L m- 2 h-1 throughout the continuous operation, suggesting that fouling did not occur at these conditions.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11