A novel approach in revealing mechanisms and particular step predictors of pH dependent tartrazine catalytic degradation in presence of Oxone®
| Autor: | Goran V. Janjić, Aleksandra Milutinović-Nikolić, Sanja Marinović, Marko Popadić, Predrag Banković, Tihana Mudrinić, Ivana S. Đorđević |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Environmental Engineering
UV–Vis Ultraviolet Rays Health Toxicology and Mutagenesis 0208 environmental biotechnology chemistry.chemical_element 02 engineering and technology 010501 environmental sciences Photochemistry 01 natural sciences DFT chemistry.chemical_compound Ultraviolet visible spectroscopy Environmental Chemistry Reactivity (chemistry) Cobalt oxide Tartrazine 0105 earth and related environmental sciences Public Health Environmental and Occupational Health Advanced oxidation processes General Medicine General Chemistry Hydrogen-Ion Concentration Sulfuric Acids Potassium peroxymonosulfate Pollution 020801 environmental engineering Oxone® chemistry Degradation (geology) Diazo GC-MS Oxidation-Reduction Cobalt Water Pollutants Chemical |
| Zdroj: | Chemosphere |
| Popis: | The degradation of tartrazine in the presence of cobalt activated Oxone® (potassium peroxymonosulfate) was investigated at different initial pH values. Aluminum pillared clay had the role of a support for catalytically active cobalt oxide species. The degradation of tartrazine and the formation of a mixture of degradation products were monitored using the Ultraviolet–Visible (UV–Vis) spectroscopy and gas chromatography–mass spectrometry (GC-MS). The exact qualitative composition of this mixture and the determination of the most probable mechanism of degradation (the primary goal) were obtained using GC-MS. Besides, the main reaction pathway (reaction with SO4˙ˉ radical anion) and secondary pathways were proposed depending on the pH value. At pH = 6 the reaction with HO˙ radical was proposed. At pH = 11 decarboxilation was suggested as the first step of the secondary proposed reaction pathway. The combination of results acquired from the deconvolution of UV–Vis spectra and the theoretical UV–Vis spectra of degradation products, whose occurrence was predicted by quantum-chemical calculations, was proven to be beneficial for the identification of tartrazine degradation products and for defining UV–Vis predictors of particular degradation steps. An additional contribution of this paper, from the reactivity aspect, was the establishment of the critical structural demand for the radical degradation of any diazo compound. The existence of a hydrogen atom bound to a diazo group was found to be the essential prerequisite for the radical cleavage of diazo compounds. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|