Carbaryl Photochemical Degradation on Soil Model Surfaces
The phototransformation of carbaryl was investigated upon solar light exposure on three surfaces, silica, kaolin and sand, as soil models. By excitation with a Suntest set up at the surface of the three solid supports, the degradation of carbaryl followed first-order kinetics with a rate constant of...
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-03-01
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| Series: | Soil Systems |
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| Online Access: | http://www.mdpi.com/2571-8789/3/1/17 |
| _version_ | 1819075262030020608 |
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| author | Marie Siampiringue Rajae Chahboune Pascal Wong-Wah-Chung Mohamed Sarakha |
| author_facet | Marie Siampiringue Rajae Chahboune Pascal Wong-Wah-Chung Mohamed Sarakha |
| author_sort | Marie Siampiringue |
| collection | DOAJ |
| description | The phototransformation of carbaryl was investigated upon solar light exposure on three surfaces, silica, kaolin and sand, as soil models. By excitation with a Suntest set up at the surface of the three solid supports, the degradation of carbaryl followed first-order kinetics with a rate constant of 0.10 h−1. By using the Kubelka Munk model, the quantum yield disappearance at the surface of kaolin was evaluated to 2.4 × 10−3. Such a value is roughly one order of magnitude higher than that obtained in aqueous solutions. The results indicated that the particle size and the specific surface area of the various models have significant effects. The photo-oxidative properties as well as the byproduct elucidation by liquid chromatography combined with diode arrays (LC-DAD) and liquid chromatography coupled mass spectrometry (LC-MS) analyses allowed us to propose the degradation mechanism pathways. The main products were 1-naphtol and 2-hydroxy-1,4-naphthoquinone, which arise from a photo-oxidation process together with products from photo-Fries, photo-ejection and methyl carbamate hydrolysis. The toxicity tests clearly showed a significant decrease of the toxicity in the early stages of the irradiation. This clearly shows that the generated products are less toxic than the parent compound. |
| first_indexed | 2024-12-21T18:22:36Z |
| format | Article |
| id | doaj.art-1289de1f8662417e9b73e35dd88b22c3 |
| institution | Directory Open Access Journal |
| issn | 2571-8789 |
| language | English |
| last_indexed | 2024-12-21T18:22:36Z |
| publishDate | 2019-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Soil Systems |
| spelling | doaj.art-1289de1f8662417e9b73e35dd88b22c32022-12-21T18:54:30ZengMDPI AGSoil Systems2571-87892019-03-01311710.3390/soilsystems3010017soilsystems3010017Carbaryl Photochemical Degradation on Soil Model SurfacesMarie Siampiringue0Rajae Chahboune1Pascal Wong-Wah-Chung2Mohamed Sarakha3Institut de Chimie de Clermont-Ferrand, Université Clermont Auvergne, 10448, F-63000 Clermont-Ferrand, FranceInstitut de Chimie de Clermont-Ferrand, Université Clermont Auvergne, 10448, F-63000 Clermont-Ferrand, FranceLaboratoire Chimie Environnement (LCE), CNRS UMR 7376, Aix Marseille University, F-13331 Marseille, FranceInstitut de Chimie de Clermont-Ferrand, Université Clermont Auvergne, 10448, F-63000 Clermont-Ferrand, FranceThe phototransformation of carbaryl was investigated upon solar light exposure on three surfaces, silica, kaolin and sand, as soil models. By excitation with a Suntest set up at the surface of the three solid supports, the degradation of carbaryl followed first-order kinetics with a rate constant of 0.10 h−1. By using the Kubelka Munk model, the quantum yield disappearance at the surface of kaolin was evaluated to 2.4 × 10−3. Such a value is roughly one order of magnitude higher than that obtained in aqueous solutions. The results indicated that the particle size and the specific surface area of the various models have significant effects. The photo-oxidative properties as well as the byproduct elucidation by liquid chromatography combined with diode arrays (LC-DAD) and liquid chromatography coupled mass spectrometry (LC-MS) analyses allowed us to propose the degradation mechanism pathways. The main products were 1-naphtol and 2-hydroxy-1,4-naphthoquinone, which arise from a photo-oxidation process together with products from photo-Fries, photo-ejection and methyl carbamate hydrolysis. The toxicity tests clearly showed a significant decrease of the toxicity in the early stages of the irradiation. This clearly shows that the generated products are less toxic than the parent compound.http://www.mdpi.com/2571-8789/3/1/17photodegradationcarbarylkaolinitesoilsolar irradiation |
| spellingShingle | Marie Siampiringue Rajae Chahboune Pascal Wong-Wah-Chung Mohamed Sarakha Carbaryl Photochemical Degradation on Soil Model Surfaces Soil Systems photodegradation carbaryl kaolinite soil solar irradiation |
| title | Carbaryl Photochemical Degradation on Soil Model Surfaces |
| title_full | Carbaryl Photochemical Degradation on Soil Model Surfaces |
| title_fullStr | Carbaryl Photochemical Degradation on Soil Model Surfaces |
| title_full_unstemmed | Carbaryl Photochemical Degradation on Soil Model Surfaces |
| title_short | Carbaryl Photochemical Degradation on Soil Model Surfaces |
| title_sort | carbaryl photochemical degradation on soil model surfaces |
| topic | photodegradation carbaryl kaolinite soil solar irradiation |
| url | http://www.mdpi.com/2571-8789/3/1/17 |
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