Photocatalytic decomposition of direct red 16 and kinetics analysis in a conic body packed bed reactor with nanostructure titania coated Raschig rings
Photocatalytic decomposition of direct red 16 and kinetics analysis in a conic body packed bed reactor with nanostructure titania coated Raschig rings
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DOI：
10.1016/j.cej.2009.03.011
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发表时间：
2009-08
影响因子：
15.1
通讯作者：
J. Saien;M. Asgari;A. Soleymani;N. Taghavinia
中科院分区：
文献类型：
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作者：
J. Saien;M. Asgari;A. Soleymani;N. Taghavinia
采用锥体填充床反应器，内照射UV-C灯，配备循环上游，研究了广泛使用的偶氮染料直接红16在水中的分解。将合成的纳米结构TiO2光催化剂颗粒固定在透明的Raschig环填料表面。染料的初始浓度为30mgL−1的溶液在纺织废水中的典型浓度范围内，在自然pH值为6.75、温度为25℃的温和操作条件下进行处理。对活性物种的研究表明，羟基在该过程中起主要作用，在90min内完全降解，因此在约60min内降解93%，在120min内约71%的芳香族基团被分解。在动力学研究中，染料的降解速率可表示为单个光解速率和光催化过程分支的速率之和，符合幂定律模型。同时，Langmuir-HinShelwood动力学模型描述了纯光催化分支的变化，符合一级幂定律模型。
A conic body packed bed reactor, internally irradiated with a UV-C lamp and equipped with circulating upflow stream was employed to investigate the decomposition of a widely used azo dye, direct red 16, in water. The synthesized nanostructure TiO2photocatalyst particles were immobilized on the surface of transparent Raschig ring packings. Solutions with initial concentration of 30mgL−1of dye, within the range of typical concentration in textile waste waters, were treated under the mild operating conditions of natural pH of 6.75 and temperature of 25°C. Investigations on the active species showed that hydroxyl radicals play the major role in the process, providing a perfect degradation in 90min of irradiation and hence 93% in about 60min; and also about 71% desired decomposition of aromatic groups in 120min. For kinetic investigations, the rate of degradation of the dye was expressed as the sum of the rates of individual photolysis and photocatalysis process branches in power law model. Meanwhile, the Langmuir–Hinshelwood kinetic model describes the variations in pure photocatalytic branch in consistent with a first order power law model.