Photocatalytic degradation of eleven microcystin variants and nodularin by TiO2 coated glass microspheres.

Pestana, Carlos J.; Edwards, Christine; Prabhu, Radhakrishna; Robertson, Peter K.J.; Lawton, Linda A.

Abstract

Microcystins and nodularin are toxic cyanobacterial secondary metabolites produced by cyanobacteria that pose a threat to human health in drinking water. Conventional water treatment methods often fail to remove these toxins. Advanced oxidation processes such as TiO2 photocatalysis have been shown to effectively degrade these compounds. A particular issue that has limited the widespread application of TiO2 photocatalysis for water treatment has been the separation of the nanoparticulate powder from the treated water. A novel catalyst format, TiO2 coated hollow glass spheres (Photospheres™), is far more easily separated from treated water due to its buoyancy. This paper reports the photocatalytic degradation of eleven microcystin variants and nodularin in water using Photospheres™. It was found that the Photospheres™ successfully decomposed all compounds in 5min or less. This was found to be comparable to the rate of degradation observed using a Degussa P25 material, which has been previously reported to be the most efficient TiO2 for photocatalytic degradation of microcystins in water. Furthermore, it was observed that the degree of initial catalyst adsorption of the cyanotoxins depended on the amino acid in the variable positions of the microcystin molecule. The fastest degradation (2min) was observed for the hydrophobic variants (microcystin-LY, -LW, -LF). Suitability of UV-LEDs as an alternative low energy light source was also evaluated.

Citation

PESTANA, C.J., EDWARDS, C., PRABHU, R., ROBERTSON, P.K.J. and LAWTON, L.A. 2015. Photocatalytic degradation of eleven microcystin variants and nodularin by TiO2 coated glass microspheres. Journal of hazardous materials [online], 300, pages 347-353. Available from: https://doi.org/10.1016/j.jhazmat.2015.07.016

• Journal Article Type: Article
• Acceptance Date: Jul 7, 2015
• Online Publication Date: Jul 9, 2015
• Publication Date: Dec 30, 2015
• Deposit Date: Feb 29, 2016
• Publicly Available Date: Jul 10, 2016
• Journal: Journal of hazardous materials
• Print ISSN: 0304-3894
• Electronic ISSN: 1873-3336
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 300
• Pages: 347-353
• DOI: https://doi.org/10.1016/j.jhazmat.2015.07.016
• Keywords: Cyanotoxins; Blue-green algae; UVLEDs; Photospheres; Water treatment
• Public URL: http://hdl.handle.net/10059/1395