Non-Thermal Plasma Mini-Reactors for Water Treatment (original) (raw)
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This work researches the possibility of increasing the dye removal efficiency from wastewater using nonthermal plasma. A study for the optimal air gap distance between dual pin and surface of Acid Blue 25 dye solution and thickness of ground plate is carried out using 3D-EM simulator to find maximum electric field intensity at the tip of both pins. The consequences display that the best gap for corona discharge is approximately 5 mm using 15 kV source. In addition, the optimum plate thickness is 0.1 mm. These distance and thickness were mentioned are constant during the study of other factors. Dual pin-to-plate high-voltage corona discharge plasma system is presented to investigation experimentally the gap distance, thickness of ground plate, initial dye concentration, pH solution and conductivity on the amount of Acid Blue 25 dye color removal efficiency from wastewater. There is a large consensus among the simulation and experimental work in the air gap and thickness of ground plate. Where the decolorization for air gap 5 mm is 95.74 at time 35 min compared with 91% and 17% for 1 mm and 20 mm gap distance respectively. Also, the discharge energy at each air gap are calculated. Measurement results for the impact of thickness of an Aluminum ground plate on color removal competence showed color removal efficiencies of 86.3%, 90.78% and 98.06%, after treatment time 15 min for thicknesses of 2, 0.5 and 0.1 mm respectively. The decolorization behavior utilizing dual pin-to-plate corona discharge plasma system display 82% pigment evacuation proficiency inside 11min. The complete decolorization was accomplished within 28min for distinctive examined introductory color focuses 5 ppm up to 100 ppm. Likewise, the impacts of conductivity by utilizing diverse salts as AlCl3, CaCl 2 , KCl and NaCl and with distinctive focuses have been explored. The rising of the solution conductivity leads to the reduction of decolorization efficiency. The decolorization efficiency and discharge energy are calculated at different concentration molarity for AlCl3, CaCl2, KCl and NaCl. It was observed that the presence of salts at the same concentration level substantially decreased the rate and the extent of decolorization. The results indicate that the optimum pH for the decolorization of Acid Blue 25 dye is in the range between 3 and 6. Furthermore the conductivity and discharge energy were measurement at each value of pH. Energy yield for decolorization and Electrical Energy per Order (EE/O) under different initial pH value were calculated. A kinetic model is used to define the performance of corona discharge system under different value of pH. The model of pseudo-zero, pseudo-first order, and pseudo-second order reactions kinetic are utilized to investigate the decolorization of Acid Blue 25 dye. The rate of degradation of Acid Blue 25 dye follows the pseudo-first order kinetics in the dye concentration. Energy consumption requirements for decolorization was considered. The outcomes will be useful for designing the plasma treatment systems suitable for industrial wastewaters.
Energies, 2016
In dye decolorization tests a non-thermal plasma (NTP) corona discharge generated by a high voltage pin-to-ground plate displayed 82% color removal within 11 min. Total color removal was accomplished after 28 min. Different salts such as KCl, NaCl, CaCl 2 and AlCl 3 were utilized to check the influence of conductivity changes on the dye decolorization process. Higher dye solution conductivity improved the color removal efficiency. The discharge energy and degradation efficiency were computed for diverse concentrations for NaCl, KCl, CaCl 2 and AlCl 3 , whereby it was noticed that the salts generally have a small impact on the level of dye decolorization using corona discharge. In addition, the essential reactive species involved in the oxidation of organic dye compounds such as ozone (O 3) generated in treated water and hydrogen peroxide (H 2 O 2) were investigated and the energetic species that produced the non-thermal plasma at the optimum operation time were determined. Energy yields for decolorization and Electrical Energy per Order (EE/O) were calculated for different concentrations of NaCl, KCl, CaCl 2 and AlCl 3. This work may help in designing plasma systems appropriate for treatment of industrial wastewaters polluted by dyes.
Investigating the Performance of Cold Plasma in Removing Methylene Blue Dye from Textile Wastewater
Journal of Water and Wastewater, 2024
Advanced oxidation process is an efficient and innovative method for the complete removal of organic pollutants, which works by using active species, especially hydroxyl radicals. In this process, different oxidation mechanisms are used. Direct electrical discharge on the surface and inside the liquid is a more complex and effective process than electrical discharge on gases. In this process, the electronic current is transferred by surface and water ions and produces plasma, which leads to chemical and physical effects such as the production of radicals and ultraviolet light. In this study, wastewater from textile industries was selected as the target wastewater. The removal of methylene blue as one of the important and toxic dyes in this type of wastewater was investigated under the influence of atmospheric pressure plasma. The electrodes used to generate plasma were made of 316 stainless steel. The experiment was carried out for a duration of 2.5 to 60 minutes. In the conducted analyses, optimal pH, suitable injected gas into the reactor, chemical oxygen demand, effective voltage (V), and distance between electrodes (d) were also studied. The results showed that corona pulse plasma had a high efficiency in dye removal, with over 99% color removal achieved in less than 10 minutes using injected oxygen gas into the system at a pH of 8 and an effective voltage of 130 kV. Additionally, the highest reduction in COD value in the corona pulse method for real textile wastewater reached from 1760 to 200 mg/L, and complete color removal was achieved, reducing its color from 2500 Pt/CO to 75 Pt/CO, indicating the extraordinary impact of this method.
Decomposition of organic dyes in water using non-thermal plasma
2009
The decomposition of the azo dye methyl red in aqueous solution was performed using a pulsed dielectric barrier discharge in coaxial configuration. The solution was made to flow as a thin layer on the surface of the inner electrode of the DBD reactor, so that the oxidizing species formed in the discharge can easily penetrate the solution, react with the dye molecules and decompose them. After 10 minutes plasma treatment 93% removal of the dye was reached for 50 mg/L initial concentration of methyl red in solution. The corresponding removal yield was 52.5 g/kWh. Lower concentrations of the dye are removed faster, however, the efficiency is lower in this case.
Treatment of Dye Wastewater by Using a Hybrid Gas/Liquid Pulsed Discharge Plasma Reactor
Plasma Science and Technology, 2012
A hybrid gas/liquid pulsed discharge plasma reactor using a porous ceramic tube is proposed for dye wastewater treatment. High voltage pulsed discharge plasma was generated in the gas phase and simultaneously the plasma channel was permeated through the tiny holes of the ceramic tube into the water phase accompanied by gas bubbles. The porous ceramic tube not only separated the gas phase and liquid phase but also offered an effective plasma spreading channel. The effects of the peak pulse voltage, additive gas varieties, gas bubbling rate, solution conductivity and TiO2 addition were investigated. The results showed that this reactor was effective for dye wastewater treatment. The decoloration efficiency of Acid Orange II was enhanced with an increase in the power supplied. Under the studied conditions, 97% of Acid Orange II in aqueous solution was effectively decolored with additive oxygen gas, which was 51% higher than that with argon gas, and the increasing O2 bubbling rate also benefited the decoloration of dye wastewater. Water conductivity had a small effect on the level of decoloration. Catalysis of TiO2 could be induced by the pulsed discharge plasma and addition of TiO2 aided the decoloration of Acid Orange II.
Degradation and detoxification efficiency of high concentrations of commercially available reactive textile dye Reactive Black 5 solution (40, 80, 200, 500, 1000 mg L-1), were studied. Advanced oxidation processes in water falling film based on dielectric barrier discharge in a non-thermal plasma reactor were used. For the first time, this reactor was used for the treatment of high concentrations of organic pollutants such as reactive textile dye Reactive Black 5 in water. Solution of the dye was plasma treated in a thin aqueous solution film that was constantly regenerated. The reactor works as a continuous flow reactor and the electrical discharge itself takes place at the gas– –liquid interphase. The dye solution was recirculated through the reactor with an applied energy density of 0–374 kJ L-1. Decolorization efficiency (%) was monitored by UV–Vis spectrophotometry. Samples were taken after every recirculation (~ 22 kJ L-1) and decolorization percentage was measured after 5 min and 24 h post plasma treatment. The efficiency of degradation (i.e., mineralization) and possible degradation products were also monitored by determination of the chemical oxygen demand (COD) and by ion chromatography (IC). Initial toxicity and toxicity of the solutions after the treatment were studied using Artemia salina test organisms. Efficiency of decolorization decreased with the increase of the dye concentration. Complete decolorization, high mineralization and non-toxicity of the solution (<10 %) were acomplished after plasma treatment using energy density of 242 kJ L-1 , while the initial concentrations of Reactive Black 5 were 40 and 80 mg L-1 .
Degradation of organic dye using plasma discharge: optimization, pH and energy
Plasma Research Express
Decolorization of Acid Orange 142 (AO142) as important water pollutant was observed on the exposure of the dye solutions to an atmospheric non-thermal gas plasma. A response surface methodology (RSM) combined with a central composite design (CCD) was utilized to optimize the main factors (variables) affecting the degradation efficiency (response) of AO142, such as the applied voltage, the gap distance between the high voltage electrode and the surface of the solution. The regression analysis showed that a first-order polynomial model well fits the experimental data with a coefficient of determination R 2 = 0.96. FT-IR, UV-Vis, TOC and GC-MS measurements were used to investigate the decolorization of the dye on exposure to the plasma discharges. A possible degradation pathway was postulated. Additionally, the conductivity and pH changes during the treatment were also evaluated. The plasma treatment combined with Fe 2+ (plasma Fenton reaction) exhibited a higher degradation efficiency, higher energy yield connected with lower energy consumption in comparison to the plasma treatment without Fe 2+ addition.
E3S Web of Conferences
Plasma electrolysis has been proved have much higher effectivity in degrading complex pollutant contained in batik dye wastewater. This study aims to investigate the effect of gas bubbles with air injection of plasma electrolysis in decolorization process. A new method to form bubbles using injection of air directly through anode with a tiny hole of glass tube is proposed. This research work presents the effects of gas injection rates on various phenomena such as electrical power of discharge pulses, concentration of OH radicals, and the decolorization percentage of remazol red as the dye waste in a batch reactor system. Experimental results showed that direct injection of air through anode can reduce the required energy for plasma generation significantly compared to non gas injection. Energy consumption for discharge plasma was observed lowered at higher rates of gas injected. Optimum gas flow rate at different voltage has been evaluated based on the physical and chemical characte...
Journal of the Brazilian Chemical Society, 2011
Este estudo investigou o efeito da temperatura da solução sobre a descoloração do azul de metileno em um reator de plasma de descarga elétrica do tipo ponta-plano. Os resultados mostraram um aumento da porcentagem inicial de descoloração do corante com o aumento da temperatura da solução de 4 para 28 o C, mas de 28 para 37 o C não houve alteração. Entretanto, quando a temperatura foi elevada para 47 o C a porcentagem de descoloração inicial do corante diminuiu. A formação de peróxido de hidrogênio em água durante o tratamento por plasma diminuiu com o aumento da temperatura de 4 para 47 o C. A reação de descoloração ocorreu por um complexo mecanismo onde processos de zero e primeira ordem ocorreram numa mesma temperatura, seguindo ordem zero no início do processo e primeira ordem com o progresso da reação. A energia de ativação envolvida no processo de primeira ordem foi de 13,09 kJ mol -1 .
Degradation of reactive orange 16 using a prototype atmospheric-pressure non-thermal plasma reactor
Facta universitatis - series: Physics, Chemistry and Technology
A prototype atmospheric pressure non-thermal corona plasma reactor system is developed and tested for the removal of commercial textile reactive dye from water. The dye can be completely degraded in water by the presented reactor system in the initial concentration range of 10-100 mg dm-3. Dye degradation rate decreases with the increase of initial dye concentration and pulse frequency. The pH of treated solutions decreases with the increase of treatment time and with the decrease of the applied frequency. Solutions electrical conductivity increases with an increase of treatment time and with the decrease of the applied frequency. The decolorization reactions follow the pseudo-first kinetics order. The changes in the treated dye solutions compositions are the consequences of injection of plasma generated reactive species from gas into the liquid through the interfacial zone.