ZnFe2O4-chitosan magnetic beads for the removal of chlordimeform by photo-Fenton process under UVC irradiation

• Published in: Journal of environmental management 2021-04, Vol.283, p.111987, Article 111987
• Main Authors: Rezgui, Soumaya, Díez, Aida M., Monser, Lotfi, Adhoum, Nafaa, Pazos, Marta, Sanromán, M. Angeles
• Format: Article
• Language: English
• Subjects: Chlordimeform; Heterogeneous process; Magnetic chitosan beads; Photo-Fenton
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2021.111987

A simple protocol was proposed for the preparation of magnetic chitosan beads ZnFe2O4-CS via a co-precipitation method. The use of synthesized magnetic ZnFe2O4-CS beads as catalyst for the heterogeneous photo-Fenton treatment of chlordimeform insecticide (CDM) was evaluated. The photo-Fenton experiments were carried out with different synthesized catalysts by varying the molar ratio Zn/Fe in chitosan beads, the catalyst concentration and pH. Under optimal conditions using 1 g of ZnFe2O4-CS beads with a molar ratio Zn/Fe = 0.35 and at pHinitial = 3, a real wastewater doped with 20 mg L−1 of CDM was treated and complete removal of the insecticide was achieved after 7 min with a total TOC removal after 2 h of treatment. The generated carboxylic acids and ions during the photo-Fenton process were identified and quantified. The stability of the photocatalytic activity of the best catalyst in terms of pollutant removal, ZnFe2O4-CS(0.35) beads with a molar ratio Zn/Fe equal to 0.35, was satisfactory validated by four consecutive cycles. This optimal catalyst was characterized, before and after use, by Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy, X-Ray Powder Diffraction and Vibrating Sample Magnetometry analysis. [Display omitted] •ZnFe2O4-CS beads were synthesized via a simple co-precipitation method.•ZnFe2O4-CS exhibited higher catalytic activity in the photo-Fenton process.•The effect of the molar ratio Zn/Fe in chitosan beads was studied.•Effective mineralization of chlordimeform insecticide under the influence of a real matrix.•Good stability and reusability of the ZnFe2O4-CS(0.35) catalyst.