Microwave assisted photocatalytic degradation of high concentration azo dye Reactive Brilliant Red X-3B with microwave electrodeless lamp as light source
Microwave assisted photocatalytic degradation of high concentration azo dye Reactive Brilliant Red X-3B with microwave electrodeless lamp as light source
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DOI：
10.1016/j.dyepig.2006.03.012
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发表时间：
2007
影响因子：
4.5
通讯作者：
Xiwang Zhang;Guoting Li;Yizhong Wang
中科院分区：
文献类型：
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作者：
Xiwang Zhang;Guoting Li;Yizhong Wang
在家用微波炉的基础上，采用新型微波无极灯作为紫外-可见光照射源，研制了一种微波辅助光催化降解水介质中高浓度环境污染物的装置（TiO 2/MWL）。以偶氮染料活性艳红X-3B为研究对象，考察了该器件在紫外-可见光/微波耦合作用下的光催化降解性能。紫外-可见光/微波辐射耦合导致更高浓度的染料在TiO 2/MWL比在传统的光催化剂的有效降解。TiO 2/MWL的光降解效率较高，染料与羟基自由基的表面反应速率常数（k）较大，染料初始浓度对光降解的影响较小。400 mg/L的X-3B在180 min内对色度和总有机碳（TOC）的去除率分别达到100%和65%。同时，以BOD 5/COD表示的染料溶液的可生化性由初始的0.03提高到0.35，表明TiO 2/MWL也可以作为生物处理的预处理工艺。无机氧化剂（H2 O2、Na 2S 2 O 8和Fe（NO3）3）的加入可显著提高TiO 2/MWL的光降解速率。
A device for microwave assisted photocatalysis (TiO2/MWL) was described based on a modified domestic microwave oven that incorporated a novel microwave electrodeless lamp as the source of UV–vis irradiation to photodegrade environmental pollutants of high concentration in aqueous media. The performance of this device was examined using the photodegradation of azo dye Reactive Brilliant Red X-3B driven by a coupled UV–vis/microwave irradiation in an aqueous TiO2dispersion. The coupled UV–vis/microwave irradiation led to effective degradation of higher concentration dyes in TiO2/MWL than in conventional photocatalysis. Higher photodegradation efficiency, higher rate constant (k) of surface reaction between dyes and hydroxyl radicals and slighter influence of the initial dye concentration on photodegradation were found in TiO2/MWL. For 400mg/L X-3B, removal of color and total organic carbon (TOC) reached 100% and 65% after 180min, respectively. Meanwhile, the biodegradability of dye solution indicated by the value of BOD5/COD increased from initial 0.03 to 0.35 which indicated that TiO2/MWL could be used as a pre-treatment process of biotreatment as well. Moreover, photodegradation rate could be enhanced evidently in TiO2/MWL by inorganic oxidizing species (H2O2, Na2S2O8and Fe(NO3)3).