Photocatalytic degradation of microcystin-LR in aqueous solutions

• Published in: Chemosphere (Oxford) 2013-01, Vol.90 (4), p.1552-1557
• Main Authors: Jacobs, Loraine C.V., Peralta-Zamora, Patricio, Campos, Francinete Ramos, Pontarolo, Roberto
• Format: Article
• Language: English
• Subjects: Applied sciences; aqueous solutions; Drinking water and swimming-pool water. Desalination; Environmental Restoration and Remediation - methods; Exact sciences and technology; Heterogeneous photocatalysis; hydroxylation; Microcystin-LR; Microcystins - analysis; Microcystins - chemistry; Oxidants, Photochemical - chemistry; Photochemical Processes; photolysis; Pollution; semiconductors; TiO2; Titanium - chemistry; titanium dioxide; Ultraviolet Rays; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - chemistry; Water Purification - methods; Water treatment and pollution; Zinc Oxide - chemistry; ZnO
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2012.09.004

► Heterogeneous photocatalytic degradation of microcystin-LR. ► High degradation capacity of bench and continuous TiO2-based process. ► Residual microcystin-LR concentrations lower than 1μgL−1. ► Multiple hydroxylations followed by elimination of labile peptide residues of the molecule. In this work, the photocatalytic degradation of aqueous microcystin-LR was studied using TiO2 and ZnO as photocatalysts. The process was optimised and characterised at the bench scale (200mL); both semiconductors exhibited a high degradation capacity at reaction times of 1min (degradation greater than 95%). The transient species that were observed indicate that the degradation occurs via the multiple hydroxylation and elimination of the labile peptide residues of the molecule. When photocatalysis was applied in a continuous treatment system (20–50L), the photocatalytic process exhibited a high degradation efficiency, which resulted in residual microcystin-LR concentrations that were less than 1μgL−1 (C0=5μgL−1).