Treatment of aquaculture wastewater contaminated with metronidazole by advanced oxidation techniques
| Autor: | Dunia E. Santiago, M.R. Espino-Estévez, Delia R. Santana, José M. Doña-Rodríguez, J.A. Ortega Méndez, O. González-Díaz |
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| Rok vydání: | 2017 |
| Předmět: |
Aqueous solution
Chemistry Materials Science (miscellaneous) Metal ions in aqueous solution 02 engineering and technology 010501 environmental sciences Management Monitoring Policy and Law 021001 nanoscience & nanotechnology 01 natural sciences Pollution Catalysis Reaction rate Hydrolysis chemistry.chemical_compound Environmental chemistry Photocatalysis Degradation (geology) 0210 nano-technology Hydrogen peroxide Waste Management and Disposal 0105 earth and related environmental sciences Water Science and Technology Nuclear chemistry |
| Zdroj: | Environmental Nanotechnology, Monitoring & Management. 8:11-24 |
| ISSN: | 2215-1532 |
| DOI: | 10.1016/j.enmm.2017.04.001 |
| Popis: | This work analyses the treatment of ornamental aquaculture wastewater contaminated with the antibiotic metronidazole (MTZ) using a reactor with supported TiO 2 . Preliminary photolysis and hydrolysis studies revealed inefficient elimination of this pollutant under the study conditions. The activity of various photocatalysts in suspension in the elimination of 40 mg·L −1 of MTZ was studied, as well as the degradation performance in different aqueous matrices using UV-A radiation. Process efficiency was strongly and negatively affected by the presence of ions in solution, with a 20% decrease in mineralization. The highest reaction rates was observed with the Evonik-P90 (0.0625 min −1 ) versus Hombikat (0.0078 min −1 ). A number of configurations were evaluated to optimise the performance of the reactor with immobilized catalyst in MTZ degradation. Different types of illumination (UV-A and UV-C) were tested as well as the positions of both lamp and catalyst inside the reactor. Various configurations were able to completely eliminate 10 mg·L −1 of MTZ. A greater efficiency was observed in general in the degradation processes with the catalyst immobilized on the outer tube with the internal UV-C lamp (k E.UVC ; 0.042 min −1 ), compared UV-A lamp (k E.UVA ; 0.022 min −1 ). The best configuration was catalyst immobilized on the outer with the internal UV-C lamp and hydrogen peroxide (k E.UVC* ; 0.055 min −1 ).The deposited catalyst was also successfully subjected to continuous re-runs using the optimised configuration with no catalyst deactivation observed. Despite a decrease in photocatalytic activity of 24% after the sixth re-run, 100% MTZ elimination was still achieved. The degradation pathway of metronidazole using TiO 2 photocatalysis has also been proposed and detoxification of the samples after the photocatalytic treatment was evaluated using V. fischeri bacteria test. |
| Databáze: | OpenAIRE |
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