Modeling and optimizing Acid Orange 142 degradation in aqueous solution by non-thermal plasma

Fahmy, Alaa; El-Zomrawy, Adham A.; Saeed, Ahmed Mohammed; Sayed, Ahmed Z.; El-Arab, Mohamed A. Ezz; Shehata, Hassan

doi:10.1016/j.chemosphere.2018.06.176

Cited by 47 publications

(16 citation statements)

References 44 publications

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“…The pH values of all the MB solutions gradually reached a certain level at the range of acidic condition. It was probably due to several special acidic compounds such as nitrous acid and nitric acid, which were originated from nitrogen in air during the discharge process as given in Equations (4)-(8) [10,22,23]. In addition, carboxylic intermediates which were produced in the MB degradation process can also contribute to a certain pH variation in solution.…”

Section: Effect Of Initial Solution Phmentioning

confidence: 99%

Degradation of Methylene Blue via Dielectric Barrier Discharge Plasma Treatment

Xie

et al. 2019

Water

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The degradation of methylene blue (MB) using an upgraded dielectric barrier discharge (DBD) plasma reactor was investigated in this paper. Air plasma was generated in the glass bead packed bed in the reactor, which was propagated into MB solution through a microporous diffuser plate. Microdischarge phenomenon can be observed on the interface of MB solution and the diffuser plate, where plasma active species were generated. The effects of air flow rate, initial solution concentration, initial solution pH, and initial solution conductivity on MB degradation were examined. Experimental results indicated that the proposed plasma reactor was effective for MB degradation. No obvious change in MB degradation efficiency was obtained for solution with various initial pH and conductivities, which suggested the potential of the reactor in actual wastewater treatment. The possible mechanism of the generation of plasma active species for MB degradation was proposed. In addition, the total organic carbon removal and chemical oxidation demand removal after 30 min treatment were 38.5% and 48.3%, which was higher than that obtained by ozone. The energy yield for MB degradation reached up to 9.3 g/kWh. Finally, a possible degradation pathway of MB solution was proposed.agents. As a promising plasma discharge mode, non-thermal plasma (NTP) technique can be utilized to degrade pollutants in wastewater at atmospheric pressure and room temperature with lower input energy than thermal plasma [8]. The typical NTP discharge in, and in contact with, liquids can be divided into three parts, namely, direct discharge in liquids, discharge in gas phase over a liquid, and discharge in multiphase environment such as bubbles or foams inside liquids [7].For discharge in gas phase over a liquid, the gas breakdown occurs in the gap between liquid and high voltage plate. Thus, plasma active species and high energy electrons are generated and then transferred into liquids to react with organic compound [9,10]. The efficiency of NTP reactors is mainly relevant to the efficiency of mass transfer between gas and liquid phases. A packed water jet bed plasma reactor was put forward by Foster et al. [11] to maximize the plasma contact area with the water. The parallel operation of multiple plasma jets or packed bed arrays of water streams are potential solutions to the scale-up problem. Tichonovas et al. [4] and Li et al. [12] proposed a dielectric barrier discharge (DBD) reactor and a gas-liquid plasma reactor, respectively. In their reactors, the gas was sent into the discharge zone, with plasma generated and dispersed into liquid phase by porous ceramic diffusers. This process can increase the efficiency of mass transfer of active species into liquid, resulting in enhanced degradation efficiency. However, the active species diffused into liquid are mostly ozone since the other active radicals dissipate during diffusion process due to their short lifetime [13]. Thus, the mineralization of contaminants in wastewater is difficult to achieve. Therefore, it ...

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Section: Effect Of Initial Solution Phmentioning

confidence: 99%

Degradation of Methylene Blue via Dielectric Barrier Discharge Plasma Treatment

Xie

et al. 2019

Water

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“…However, the homogeneous character of these catalysts should be underlined, besides potential complications in their management, during the treatment and final disposal of the wastewater, due to the possible formation of sludge caused by the precipitation of the metals used or due to the presence of a residue in high concentrations. More specifically, as regards the degradation of the dyes in aqueous solution, in the literature, there are some studies that report the use of catalyst in an NTP reactor [38][39][40]. Fahmy et al [38] reported the results of the use of a corona discharge NTP reactor, operating with a voltage of 12.5 kV and coupled with a catalyst based on Fe 2+ (homogenous phase) for the degradation of acid orange 142 (20 mg/L) in aqueous solution.…”

Section: Introductionmentioning

confidence: 99%

“…More specifically, as regards the degradation of the dyes in aqueous solution, in the literature, there are some studies that report the use of catalyst in an NTP reactor [38][39][40]. Fahmy et al [38] reported the results of the use of a corona discharge NTP reactor, operating with a voltage of 12.5 kV and coupled with a catalyst based on Fe 2+ (homogenous phase) for the degradation of acid orange 142 (20 mg/L) in aqueous solution. Optimal results were obtained using a specific catalyst dosage (0.9 mM of Fe 2+ ): after 20 min of treatment, in the presence of Fe 2+ catalyst, the discoloration was equal to 95%.…”

Section: Introductionmentioning

confidence: 99%

Degradation of Acid Orange 7 Azo Dye in Aqueous Solution by a Catalytic-Assisted, Non-Thermal Plasma Process

et al. 2020

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The aim of this work was the optimization of the performance of the cold plasma technology coupled with a structured catalyst for the discoloration and mineralization of “acid orange 7” (AO7) azo dye. The structured catalyst consists of Fe2O3 immobilized on glass spheres, and it was prepared by the “dip coating” method and characterized by different chemico-physical techniques. The experiments were carried out in a dielectric barrier discharge (DBD) reactor. Thanks to the presence of the catalytic packed material, the complete discoloration and mineralization of the dye was achieved with voltage equal to 12 kV, lower than those generally used with this technology (approximately 20–40 kV). The best result in terms of discoloration and mineralization (80% after only 5 min both for discoloration and mineralization) was obtained with 0.25 wt% of Fe2O3 immobilized on the glass spheres, without formation of reaction by-products, as shown by the HPLC analysis. The optimized catalyst was reused for several reuse cycles without any substantial decrease of performances. Moreover, tests with radical scavengers evidenced that the most responsible oxidizing species for the degradation of AO7 dye was O2•−.

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“…7 When an appropriate amount of Fe 2+ -containing substance is added, a Fenton system is formed, and a large amount of $OH is generated aer the reaction, which increases the amount of active substance, thereby accelerating the degradation of organic matter. 8 Plasma technologies applied for the plasma/Fenton process include glow discharge (GDP) plasma, 9,10 high voltage pulsed discharge plasma (PDP), 11 gliding arc discharge (GAP) plasma 12,13 and DBD plasma. 14 Hu et al 9 studied the synergistic effect of the GDP/ Fenton system and found that GDP can be signicantly enhanced by the addition of iron ions as both Fenton catalysts and occulants.…”

Section: Introductionmentioning

confidence: 99%