Prozac® removal promoted by HAP:Nb2O5 nanoparticles system: by‐products, mechanism, and cytotoxicity assessment

• Published in: Journal of environmental chemical engineering Vol. 9; no. 2; p. 104820
• Main Authors: Malafatti, João O.D., Moreira, Ailton J., Sciena, Camila R., Silva, Thales E.M., Freschi, Gian P.G., Pereira, Ernesto C., Paris, Elaine C.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2021
• Subjects: Cytotoxicity; Emerging contaminants; Hydroxyapatite; Mechanism; Nanocomposite; Niobium oxide; Cytotoxicity; Nanocomposite; Hydroxyapatite; Niobium oxide; Emerging contaminants; Mechanism
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2020.104820

The elucidation of photocatalysis and adsorption mechanisms in the pollutant removal, as well as the efficiency for each process, provide key information for polluted water remediation. In this respect, the present study analyzed the application of nanomaterials based on niobium pentoxide (Nb2O5) and hydroxyapatite (HAP) during Prozac® and 4-(trifluoromethyl)phenol (TFMP) photodegradation. Removals for Prozac® and TFMP were respectively 93% after 2 min and 64% after 5 min. The photodegradation kinetic constants by Nb2O5 nanoparticles were 2.1 min‐1 (R2 = 0.943) and 0.185 min‐1 (R2 = 0.994), respectively, for Prozac® and TFMP, using a Hg-MDEL reactor operating at 70 W microwave power. A detailed study of the mechanisms for Prozac® and TFMP photodegradation was carried out, confirming that the adsorptive, oxidative, and photolytic processes work together to remove and/or convert the compounds into by-products. Therefore, Prozac® and the main by-products were quantified, and the cytotoxicity response was evaluated using the Lepidium sativum and Allium cepa plants. The results showed that 3-phenyl-propyl-methylamine (PPMA) by-product was more toxic than Prozac® to plant growth, exhibiting seed seability of 4% (PPMA), 33% (Prozac®), 77% (α-[2-(Methylamino) ethyl] benzyl-alcohol, MAEB), and 81% (TFMP). Furthermore, the presence of these contaminants may increase phytotoxicity at the cellular level, fostering mutation, and cell death. Schematic representation of Prozac® photocatalysis in Hg-MDEL reactor and by-products cytotoxicity [Display omitted] •Photocatalytic degradation of Prozac® and TFMP using nanomaterials based on HAP and Nb2O5.•Microwave discharge electrodeless mercury lamp (Hg-MDEL) operating in low microwave power as photochemical reactor.•Quantitatively monitoring of TFMP, MAEB and PPMA sub-products and understanding of different degradation mechanism.•TFMP was the main sub-product of Prozac® and showed greater persistence to the degradation process.•Cytotoxic assays showed that PPMA was the most toxic than Prozac® and the other by-products.