Environmental Remediation by an Integrated Microwave/UV Illumination Technique. 8. Fate of Carboxylic Acids, Aldehydes, Alkoxycarbonyl and Phenolic Substrates in a Microwave Radiation Field in the Pre
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- 作者：Satoshi Horikoshi ; Fukuyo Hojo ; Hisao Hidaka ; and Nick Serpone
- 刊名：Environmental Science & Technology
- 出版年：2004
- 出版时间：April 1, 2004
- 年：2004
- 卷：38
- 期：7
- 页码：2198 - 2208
- 全文大小：305K
- 年卷期：v.38,no.7(April 1, 2004)
- ISSN：1520-5851
文摘
Thermal and nonthermal effects originating when asystem is subjected to a microwave radiation field in the TiO2-photocatalyzed transformation of model substancescontaining various functional groups (e.g., benzoic acid,phthalic acid, o-formylbenzoic acid, phthalaldehyde, succinicacid, dimethyl phthalate, diethyl phthalate, and phenol)have been examined under simultaneous irradiation byultraviolet (UV) and microwave (MW) radiations. Characteristics of the microwave effects and the fate of eachsubstrate during the microwave-assisted photocatalyticprocess were monitored by UV absorption spectroscopy,HPLC methods, total organic carbon assays, and identificationof intermediates using electrospray mass spectraltechniques. Microwave thermal and nonthermal effectswere delineated by comparing results from MW-generatedinternal heat versus conventional external heating, andat constant ambient temperature under a microwave field.Factors involved in the nonthermal component of themicrowave radiation were inferred for the initial adsorptionof the substrate and its subsequent degradation occurringon the surface of TiO2 particles. Microwave effectsbear on the mechanism through which a model substrateundergoes oxidative degradation. A characteristic featureof these effects was briefly examined by considering thebehavior of polar (dipole moments) substrates in a microwaveradiation field.