Gliding arc plasma assisted photocatalytic degradation of anthraquinonic acid green 25 in solution with TiO2

• Published in: Applied catalysis. B, Environmental Vol. 72; no. 3-4; pp. 304 - 313
• Main Authors: Ghezzar, M.R., Abdelmalek, F., Belhadj, M., Benderdouche, N., Addou, A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30-03-2007; Elsevier
• Subjects: Anthraquinonic dye; Catalysis; Chemistry; Degradation; Exact sciences and technology; General and physical chemistry; Gliding arc; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Plasmacatalysis; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; TiO2; Degradation; Anthraquinonic dye; Gliding arc; Plasmacatalysis; TiO2; Plasma; Anthraquinone derivatives; Dyes; Photocatalysis; Transition element compounds; Heterogeneous catalysis; Acids; Titanium oxide; Environmental protection
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2006.11.008

Anthraquinonic acid green 25 (AG 25) removal was investigated by plasmachemistry using non-thermal gliding arc at atmospheric pressure. The gaseous species formed in the discharge, and especially OH radicals, induce strong oxidizing effects in the target solution. The removal of the dye was carried out in the absence and presence of TiO2 as photocatalyst. The decolourization of AG 25 was followed by UV–vis spectrometry (at 643nm), while the degradation was followed by COD measurements. The effects of operating variables such as initial concentration of AG 25 and catalyst concentration were investigated. Experiments were carried out to optimise the amount of TiO2. The results showed that maximum degradation was attained for 2gL−1 TiO2 concentration. At this optimum concentration, the dye (80μM) was totally decolourized within 15min of plasma-treatment time, and 93% removal of initial COD was attained after a 180-min plasma-treatment time. In the absence of catalyst, colour removal was 46% after 15min, while COD abatement reached 84% after 180min. The extent of degradation decreased with initial concentration and the time required for complete degradation increased. In all cases, the plasma-treated samples in the presence or absence of catalyst were found to follow pseudo-first order reaction kinetics. The TiO2-mediated plasmachemical process showed potential application for the treatment of dye solutions, resulting in the mineralization of the dye confirmed by sulfate ion formation.