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Degradation of microcystin-LR and cylindrospermopsin by continuous flow UV-A photocatalysis over immobilised TiO2.

Camacho-Muñoz, Dolores; Fervers, Anne-Sophie; Pestana, Carlos J.; Edwards, Christine; Lawton, Linda A.

Authors

Dolores Camacho-Muñoz

Anne-Sophie Fervers



Abstract

The increasing presence of freshwater toxins have brought new challenges to preserve water quality due to their potential impact on the environment and human health. Two commonly occurring cyanotoxins, microcystin-LR and cylindrospermopsin, with different physico-chemical properties were used to evaluate the efficiency of photocatalysis using a continuous-flow reactor with immobilized TiO2 on glass tubes and UV-A light. The effect of flow rate and hydrogen peroxide addition on the efficiency of cyanotoxin removal were evaluated. An analysis of the effects on microcystin-LR removal efficiency showed that low flow rates (1 mL/min) and high H2O2 concentrations (120 mg/L) were needed to provide effective degradation. Up to 27.9% and 39.1% removal of MC-LR and CYN, respectively were achieved by UV-A/TiO2 after a single pass through the reactor. A slight increase of the removal of both cyanotoxins was observed when they were in a mixture (35.5% of MC-LR and 51.3% of CYN). The addition of H2O2 to the UV/TiO2 system led to an average removal enhancement of 92.6% of MC-LR and of 29.5% of CYN compared to the UV/TiO2 system. Photolysis assisted by H2O2 degraded MC-LR by up to 77.7%. No significant removal ([less than] 10%) was observed by photolysis alone or physical alone or physical adsorption. This study presents a proof-of-principle that demonstrates the feasibility for this technology to be integrated in large-scale applications.

Citation

CAMACHO-MUĂ‘OZ, D., FERVERS, A.-S., PESTANA, C.J., EDWARDS, C. and LAWTON, L.A. 2020. Degradation of microcystin-LR and cylindrospermopsin by continuous flow UV-A photocatalysis over immobilised TiO2. Journal of environmental management [online], 276, article ID 111368. Available from: https://doi.org/10.1016/j.jenvman.2020.111368

Journal Article Type Article
Acceptance Date Sep 7, 2020
Online Publication Date Sep 14, 2020
Publication Date Dec 15, 2020
Deposit Date Sep 22, 2020
Publicly Available Date Sep 15, 2021
Journal Journal of Environmental Management
Print ISSN 0301-4797
Electronic ISSN 1095-8630
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 276
Article Number 111368
DOI https://doi.org/10.1016/j.jenvman.2020.111368
Keywords Photocatalysis; Cyanotoxin; Hydrogen peroxide; Immobilized titanium dioxide
Public URL https://rgu-repository.worktribe.com/output/968513
Related Public URLs https://rgu-repository.worktribe.com/output/969451