| Title: | Influence of pesticide concentration on their heterogeneous atmospheric degradation by ozone |
| Author(s): | Mattei C; Dupont J; Wortham H; Quivet E; |
| Address: | "Aix Marseille Univ, CNRS, LCE, Marseille, France; French Environment and Energy Management Agency 20, Avenue du Gresille, BP 90406, Angers Cedex 01, 49004, France. Aix Marseille Univ, CNRS, LCE, Marseille, France. Aix Marseille Univ, CNRS, LCE, Marseille, France. Electronic address: etienne.quivet@univ-amu.fr" |
| DOI: | 10.1016/j.chemosphere.2019.04.082 |
| ISSN/ISBN: | 1879-1298 (Electronic) 0045-6535 (Linking) |
| Abstract: | "A fraction of the atmospheric pesticides can be adsorbed on particles surface according to their physicochemical properties. After adsorption, pesticides can undergo heterogeneous reactivity with atmospheric oxidants such as ozone, but the influence of the pesticide surface coating (i.e., the percentage of the particle surface covered by pesticide molecules) on the degradation kinetics is not well-understood. To estimate the importance of this phenomenon, the influence of the surface coating level in pesticides on the heterogeneous ozonolysis of cyprodinil, deltamethrin, permethrin, and pendimethalin adsorbed on hydrophobic and hydrophilic silicas was investigated. Surface coating level varied from 0.3% to 15% of a monolayer. Generally, the increase of the surface coating level induced a slower degradation of the pesticides above 1%-3% of a monolayer. This decrease was attributed to a shielding effect. More aggregates of pesticides form with increasing surface coating leading to lower accessibility for ozone to the adsorbed pesticide molecules. Moreover, it was observed that the particle type could play a role in the influence of the surface coating level on the degradation rates. Results obtained will contribute to a better understanding of the atmospheric fate of pesticides and semi-volatile organic compounds in the particulate phase and show the importance of working with consistent surface coating level in order to compare the obtained degradation constants" |
| Keywords: | Adsorption Air Pollutants/analysis/chemistry Kinetics Nitriles Ozone/*chemistry Particulate Matter/chemistry Permethrin Pesticides/analysis/*chemistry Pyrethrins Atmosphere Degradation Heterogeneous Ozone Pesticides Surface coating; |
| Notes: | "MedlineMattei, Coraline Dupont, Julien Wortham, Henri Quivet, Etienne eng England 2019/04/26 Chemosphere. 2019 Aug; 228:75-82. doi: 10.1016/j.chemosphere.2019.04.082. Epub 2019 Apr 17" |
