Removal of caffeine from water by combining dielectric barrier discharge (DBD) plasma with goethite

• Published in: Journal of Saudi Chemical Society Vol. 21; no. 5; pp. 545 - 557
• Main Authors: Wang, Jian, Sun, Yabing, Jiang, Hao, Feng, Jingwei
• Format: Journal Article
• Language: English
• Published: Riyadh, Saudi Arabia Elsevier B.V 01.07.2017; Saudi Chemical Society; Elsevier
• Subjects: Caffeine; Dielectric barrier discharge; Goethite; Plasma; التفريغ الكهربائي; الجيوثايت; الكافيين; Plasma; Dielectric barrier discharge; Goethite; Caffeine
• ISSN: 1319-6103
• DOI: 10.1016/j.jscs.2016.08.002

In this research, dielectric barrier discharge plasma was developed to cooperate with goethite for removing caffeine in aqueous solution. Goethite was characterized by X-ray diffraction and scanning electron microscopy. The effects of input power, initial concentration and catalysts concentration on the removal efficiency of caffeine were evaluated. Furthermore, the degradation pathways of caffeine were also discussed preliminarily. In the case of caffeine concentration at 50mgL−1, the degradation efficiency of caffeine was improved from 41% to 94% after 24min on the conditions of input power of 75W by combining goethite catalysts (2.5gL−1), while the energy efficiency could be enhanced 1.6–2.3 times compared to the single DBD reactor. The reaction mechanism experiments demonstrated that attack by hydroxyl radical and ozone was the main degradation process of caffeine in aqueous solution. These studies also provided a theoretical and practical basis for the application of DBD-goethite in treatment of caffeine from water.