OH-initiated transformation and hydrolysis of aspirin in AOPs system: DFT and experimental studies
| Autor: | Fan-ping Zhu, Xiaomin Sun, Lin He, Shaojie Ren, Shu-Guang Wang |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Environmental Engineering
02 engineering and technology 010501 environmental sciences 01 natural sciences chemistry.chemical_compound Hydrolysis Transition state theory Reaction rate constant Computational chemistry Environmental Chemistry Organic chemistry Benzene Waste Management and Disposal 0105 earth and related environmental sciences Aspirin Hydroxyl Radical Hydrogen Peroxide 021001 nanoscience & nanotechnology Pollution Bond-dissociation energy Kinetics chemistry Potential energy surface Degradation (geology) Density functional theory 0210 nano-technology Oxidation-Reduction |
| Zdroj: | The Science of the total environment. 592 |
| ISSN: | 1879-1026 |
| Popis: | Advanced oxidation processes (AOPs) are widely used in wastewater treatment of pharmaceutical and personal care products (PPCPs). In this work, the OH-initiated transformation as well as the hydrolysis of a typical PPCPs, aspirin, was investigated using density functional theory (DFT) calculations and laboratory experiments. For DFT calculations, the frontier electron densities and bond dissociation energies were analyzed. Profiles of the potential energy surface were constructed, and all the possible pathways were discussed. Additionally, rate constants for each pathway were calculated with transition state theory (TST) method. UV/H2O2 experiments of aspirin were performed and degradation intermediates were identified by UPLC-MS-MS analysis. Different findings from previous experimental works were reported that the H-abstraction pathways at methyl position were dominated and OH-addition pathways on benzene ring were also favored. Meantime, hydroxyl ASA was confirmed as the main stable intermediate. Moreover, it was the first time to use DFT method to investigate the hydrolysis mechanisms of organic ester compound. |
| Databáze: | OpenAIRE |
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