Synergy of ozonation and photocatalysis to mineralize low concentration 2,4-dichlorophenoxyacetic acid in aqueous solution
| Autor: | Hiroaki Ozaki, Rabindra Raj Giri, Takehiro Ishida, Shogo Taniguchi, Ryohei Takanami |
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| Rok vydání: | 2007 |
| Předmět: |
Environmental Engineering
Photochemistry Ultraviolet Rays Health Toxicology and Mutagenesis Kinetics Catalysis Water Purification Chemical kinetics chemistry.chemical_compound Ozone Reaction rate constant Environmental Chemistry Titanium Aqueous solution Public Health Environmental and Occupational Health General Medicine General Chemistry Mineralization (soil science) Pollution chemistry Photocatalysis Hydroxyl radical 2 4-Dichlorophenoxyacetic Acid Water Pollutants Chemical |
| Zdroj: | Chemosphere. 66:1610-1617 |
| ISSN: | 0045-6535 |
| DOI: | 10.1016/j.chemosphere.2006.08.007 |
| Popis: | Concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) may affect its degradation kinetics in advanced oxidation systems, and combinations of two or more systems can be more effective for its mineralization at low concentration levels. Degradations and mineralizations of 0.045mM 2,4-D using O(3), O(3)/UV, UV/TiO(2) and O(3)/UV/TiO(2) systems were compared, and influence of reaction temperature on the mineralization in O(3)/UV/TiO(2) system was investigated. 2,4-D degradations by O(3), O(3)/UV and UV/TiO(2) systems were similar to the results of earlier investigations with higher 2,4-D concentrations. The degradations and total organic carbon (TOC) removals in the four systems were well described by the first-order reaction kinetics. The degradation and removal were greatly enhanced in O(3)/UV/TiO(2) system, and further enhancements were observed with larger O(3) supplies. The enhancements were attributed to hydroxyl radical (()OH) generation from more than one reaction pathway. The degradation and removal in O(3)/UV/TiO(2) system were very efficient with reaction temperature fixed at 20 degrees C. It was suspected that reaction temperature might have influenced ()OH generation in the system, which needs further attention. |
| Databáze: | OpenAIRE |
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