Abstract
The photodegradation of herbicide 2,4-Dichlorophenoxyacetic acid (2,4-D) by bismuth tungstate with or without hydrogen peroxide by visible light was investigated. The photocatalytical reactions were studied under various conditions including the examination of the effects of initial pH, 2,4-D concentrations, light intensities, and hydrogen peroxide. Photocatalytic reactions were optimized at pH 5, higher or lower pH levels will reduce the decay rate due to the phase change of 2,4-D molecules and/or bismuth tungstate. The increase of catalyst/[2,4-D] ratio and light intensity were found to improve the 2,4-D decay rates, due to the increment of number of active sites and electron-holes on the Bi2WO6surface, respectively. The involvement of H2O2in the Bi2WO6photocatalytic process can effectively double the 2,4-D decay rate, however, this was observed within a narrow gap of H2O2dosages and easily overdosed, a precise control of H2O2dosing is critical for a successful application. Kinetic models were derived successfully, so that the process performance is predictable by incorporating initial pH level, 2,4-D concentration, light intensities, and hydrogen peroxide.
Original language | English |
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Pages (from-to) | 665-669 |
Number of pages | 5 |
Journal | Chemical Engineering Journal |
Volume | 223 |
DOIs | |
Publication status | Published - 1 May 2013 |
Keywords
- 2,4-Dichlorophenoxyacetic acid
- Bismuth tungstate
- Hydrogen peroxide
- Visible light
ASJC Scopus subject areas
- General Chemical Engineering
- General Chemistry
- Industrial and Manufacturing Engineering
- Environmental Chemistry