Advantages of TiO2/5A composite catalyst for photocatalytic degradation of antibiotic oxytetracycline in aqueous solution: Comparison between TiO2 and TiO2/5A composite system
Advantages of TiO2/5A composite catalyst for photocatalytic degradation of antibiotic oxytetracycline in aqueous solution: Comparison between TiO2 and TiO2/5A composite system
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DOI：
10.1016/j.cej.2014.03.050
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发表时间：
2014-07
影响因子：
15.1
通讯作者：
Chun Zhao;Yu Zhou;D. Ridder;J. Zhai;Yunmei Wei;Huiping Deng
中科院分区：
文献类型：
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作者：
Chun Zhao;Yu Zhou;D. Ridder;J. Zhai;Yunmei Wei;Huiping Deng
为探索TiO 2/5A沸石复合体系的优越性，研究了负载型TiO 2和负载15%TiO2（15%T5A）的5A沸石在一系列条件下对土霉素（OTC）的光催化降解和吸附性能。初步吸附结果表明，除高pH值（pH ≥ 11）外，5A对土霉素的吸附效果均优于TiO 2。采用多变量分析和响应曲面法（RSM）建立了土霉素去除率与初始pH值和催化剂投加量之间的二次函数模型。当T5 A投加量为15%时，最佳的土霉素去除条件为：pH为5和7时为1.00 g/L，pH为9时为0.80 g/L，pH为11时为0.68 g/L。在此条件下，15%T5A复合光催化剂比非负载型TiO 2显示出更快的OTC去除和降解速度。此外，在pH为7的条件下，在UV + TiO 2和UV + 15%T5A光催化降解土霉素的过程中，加入了竞争性有机物叔丁醇（TBA）、甲醇和湿润酸。实验结果表明，15%T5A复合体系比未负载TiO 2具有更好的抗自由基清除剂和低浓度潮湿酸的干扰能力。此外，15%T5A在回收使用过程中表现出更稳定的活性，并且比纳米TiO 2具有更快的沉降性能。
To probe advantages in TiO2/5A zeolite composite system, the photocatalytic degradation and adsorption of the antibiotic oxytetracycline (OTC) by unsupported TiO2and 5A zeolite coated with 15 mass% TiO2(15%T5A) under a series of conditions were investigated. The primary adsorption results indicated that 5A had much better adsorptive capability of OTC than TiO2except at high pH values (pH ≧ 11). A multivariate analysis and a response surface methodology (RSM) were applied to develop a quadratic model as a functional relationship between OTC removal efficiency and the independent variables (the initial pH values and the dosage of the catalyst). The optimal OTC removal conditions found with 15%T5A dosage were 1.00 g/L for pH 5 and 7, 0.80 g/L for pH 9, and 0.68 g/L for pH 11. Under these conditions, the 15%T5A composite photocatalysis showed a quicker OTC removal and degradation speed than unsupported TiO2. Besides, competitive organics liketert-butyl alcohol (TBA), methanol and humid acid, were added during the photocatalytic degradation of OTC by UV + TiO2and UV + 15%T5A at pH 7. The experimental results indicated that the 15%T5A composite system had a better anti-interference capability of radical scavengers, and humid acid at a low concentration than unsupported TiO2. Moreover, the 15%T5A proved a more stable activity during recycled use and a much quicker sedimentation performance than nano-TiO2.