Effect of inorganic ions on the photocatalytic treatment of agro-industrial wastewaters containing imazalil

• Published in: Applied catalysis. B, Environmental Vol. 156-157; pp. 284 - 292
• Main Authors: Santiago, Dunia E., Araña, J., González-Díaz, O., Alemán-Dominguez, M.E., Acosta-Dacal, Andrea C., Fernandez-Rodríguez, C., Pérez-Peña, J., Doña-Rodríguez, José M.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01-09-2014; Elsevier
• Subjects: Bacteria; Banana postharvest; Catalysis; Chemistry; Degradation; Exact sciences and technology; Fungicides; General and physical chemistry; Imazalil; Ions; Mineralization; Photocatalysis; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Titanium dioxide; Waste water; Wastewater; Ions; Imazalil; Wastewater; Photocatalysis; Banana postharvest; Heterogeneous catalysis; Industrial waste water; Agricultural production; Banana; Waste water; Environmental protection
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2014.03.022

•The photocatalytic elimination of imazalil was proved for different water matrices.•Commercial Evonik P25 and a home-made photocatalyst were studied and compared.•The effect of different cations and anions was evaluated at different pH values.•FTIR studies confirmed the interaction of ions with the photocatalyst surface.•The degradation pathway of imazalil was confirmed for the different water matrices.
In this work we studied the elimination, mineralization and detoxification of wastewaters from banana postharvest industries, contaminated with the fungicide imazalil, by means of heterogeneous advanced oxidation processes. We compared the activity of the commercial photocatalyst Evonik P25 and the lab-made EST-1023t in the degradation of imazalil in deionized water and in industrial wastewater. Results show an important negative water-matrix effect for wastewater treatment at acidic pH values due, mainly, to the presence of ions adsorbed onto the TiO2 photocatalyst surface. At pH 7 only bicarbonate anions and bacteria hindered the degradation and mineralization of imazalil. Mineralization of imazalil was completely inhibited by dissolved aluminium in concentrations as low as 5mgL−1.