Highly efficient degradation of azo dye Orange G using laterite soil as catalyst under irradiation of non-thermal plasma
Highly efficient degradation of azo dye Orange G using laterite soil as catalyst under irradiation of non-thermal plasma
复制标题
DOI：
10.1016/j.apcatb.2019.01.066
复制
发表时间：
2019-06
期刊：
影响因子：
--
通讯作者：
Jean-Baptiste Tarkwa;E. Acayanka;B. Jiang;N. Oturan;Georges Y. Kamgang;S. Laminsi;M. Oturan
中科院分区：
文献类型：
--
作者：
Jean-Baptiste Tarkwa;E. Acayanka;B. Jiang;N. Oturan;Georges Y. Kamgang;S. Laminsi;M. Oturan
本研究以含有多种矿物氧化物(如Al_2O_3、Fe_2O_3、TiO_2)的红壤为催化剂，结合滑动弧光等离子体处理技术，对水溶液中橙黄G(OG)的降解进行了研究。结果表明，在等离子体处理的OG溶液中加入红壤(作为催化剂)，降解效率从单独等离子体处理的17%提高到近100%。与P25TiO2光催化剂、Fe2O3光催化剂和TiO2Fe2O3光催化剂相比，红土等离子体处理60 后，OG的脱色率分别从56%、68%和75%提高到100.00%。在焙烧红土中，Fe_2O_3不仅由于其窄的带隙被认为是TiO_2敏化剂，而且还被认为是多相Fenton催化剂。这些协同作用增强了滑动弧光等离子体系统中活性物种，即自由基dotOH的生成，从而提高了脱除OG的工艺效率。在优化的操作条件下，联合工艺处理OG溶液在60 分钟内可达到约83%的矿化度。从动力学角度看，OG的氧化符合朗缪尔-辛舍伍德模型，二级速率常数KR和吸附常数Ks分别为5.74 mg −1和0.12 L mg−1，表明反应发生在催化剂表面。连续循环5次后，催化剂仍具有较高的稳定性。
In this study, laterite soil containing various mineral oxides (e.g., Al2O3, Fe2O3and TiO2), used as an alternative catalyst, was combined with gliding arc plasma treatment for Orange G (OG) degradation in aqueous solution. The results showed that the incorporation of laterite soil (as catalyst) in (OG solution exposed to plasma led to a significant degradation enhancement from 17% for plasma treatment alone to almost 100%. Compared with P25 TiO2, Fe2O3, and TiO2/Fe2O3photocatalysts, the decolorization rate of OG can be increased from 56, 68 and 75% respectively to 100% after 60 min laterite-mediated plasma treatment. In the calcinated laterite, Fe2O3was considered not only as TiO2sensitizer due to its narrow band-gap but also as the heterogeneous Fenton catalyst. These synergistically enhanced the generation of the reactive species, i.e.,radical dotOH, in the gliding arc plasma system and thus process efficiency for OG removal. Under optimized operating conditions, approximately 83% mineralization of OG solution was achieved within 60 min of treatment with the combined process. From the kinetics point of view, OG oxidation fitted with Langmuir–Hinshelwood model with the second-order rate constant (kr) and adsorption constant (Ks) of 5.74 mg min−1and 0.12 L mg−1, respectively, suggesting that the reaction occurs at the catalyst surface. The catalyst was highly stable even after 5 consecutive cycles.