Photocatalytic degradation of sulfamethoxazole using TiO2 in simulated seawater: evidence for direct formation of reactive halogen species and halogenated by-products
Combined sewer overflows (CSO), generated during the wet weather flow from the combination of the inflow and stormwater runoff in sewer system, result in an overflow of untreated wastewater from sewer system, which might ultimately contain different micropollutants (MPs). In this study, a coagulatio...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositorio: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2445/184662 |
| Acceso en línea: | https://hdl.handle.net/2445/184662 |
| Access Level: | acceso abierto |
| Palabra clave: | Fotocatàlisi Halògens Diòxid de titani Nanopartícules Photocatalysis Halogens Titanium dioxide Nanoparticles |
| Sumario: | Combined sewer overflows (CSO), generated during the wet weather flow from the combination of the inflow and stormwater runoff in sewer system, result in an overflow of untreated wastewater from sewer system, which might ultimately contain different micropollutants (MPs). In this study, a coagulation-flocculation-sedimentation (CFS) pretreated CSO spiked with MPs was treated by catalytic ozonation using carbon, iron and peroxide based catalysts. The catalysts were characterized and their activity on MPs removal was studied at two different ozone (O3) doses (5 and 10 mg L‒1). The effect of the treatment on the spiked CSO effluent was also assessed from the acute toxicity of the effluent using Microtox®, Yeast and Macrophage cell-line toxicity assay tests. All the carbon-based catalysts showed large surface area, which was strongly influenced by the activation technique in the preparation of the catalyst. The CFS treatment strongly reduced the turbidity (≥ 60%) but had marginal effect on the UV254, dissolved organic carbon (DOC) and pH. Sludge Based Carbon (SBC) showed strong adsorption capacity (≥ 60% removal efficiency) for all MPs studied compared to other carbon and iron-based catalysts. Ozonation alone was effective for the degradation of easily oxidizable MPs (sulfamethoxazole, mecoprop, and 2,4-dichlorophenoxyl acetic acid), achieving more than 80% degradation efficiency at 10 mg L‒1 of ozone, but not effective for atrazine (≤ 60% degradation efficiency) at similar O3 dose. Catalytic ozonation (at 10 mg L‒1 O3 dose) improved the degradation of the MPs at low catalyst dosage but higher dosage strongly inhibited their degradation. In all cases, the effluents showed negligible acute toxicity, indicating the suitability of the process for the treatment of CSO. |
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