Removal of Trichloroethylene by Corona Radical Injection

2019 ◽  
Vol 960 ◽  
pp. 115-121
Author(s):  
Zhan Guo Li ◽  
Hong Jie Zhao
Keyword(s):  
Water Vapor ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Gas Flow ◽  
Active Oxygen Species ◽  
High Energy ◽  
Decomposition Mechanism ◽  
Gas Flow Rate ◽  
Initial Concentration ◽  
Vapor Injection

The removal of trichloroethylene (TCE) by corona discharge plasma was investigated. The influences of initial concentration, gas flow rate, injection of water vapor and ozone (O3) on removal efficiency were discussed. The results show that removal efficiency reduces with the initial concentration and gas flow rate increasing. A proper quantity of water vapor injection can improve the removal efficiency, but which is not always increased, due to the electronegative characteristic of water molecule. The maximum removal efficiency of 90.7% can be obtained in wet air flow with relative humidity of 70.6%. The removal efficiency increases obviously with O3 injection. The decomposition products are 2,2-Dichloroacetyl chloride (CHCl2COCl), carbonyl chloride (COCl2), hydrogen chloride (HCl) and carbon dioxide (CO2), based on which the decomposition mechanism is discussed. The oxygen chain reaction is the primary decomposition mechanism, and high energy electrons and active oxygen species play a leading role in the decomposition process. Therefore, removal efficiency of TCE can be improved greatly when water vapor and O3 is injected.

Degradation of Organophosphorus Pesticide in a Packed-Bed Plasma Reactor: Effects of Operating Parameters and Kinetics Study

2013 ◽  
Vol 781-784 ◽  
pp. 1637-1645 ◽  
Author(s):  
Ting Jun Ma ◽  
Yi Qing Xu
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Gas Flow ◽  
Plasma Reactor ◽  
Organophosphorus Pesticide ◽  
Packed Bed ◽  
Pulse Frequency ◽  
Gas Flow Rate ◽  
Peak Voltage ◽  
Initial Concentration

The degradation effectiveness and reaction kinetics of representative organophosphorus (OP) pesticide in a packed-bed plasma reactor have been studied. Important parameters, including peak voltage, pulse frequency, gas-flow rate, initial concentration, diameter of catalyst particles, and thickness of catalyst bed which influences the removal efficiency, were investigated. Experimental results indicated that rogor removal efficiency as high as 80% can be achieved at 35 kV with the gas flow rate of 800 mL/min and initial concentration of 11.2 mg/m3.The removal efficiency increased with the increase of pulsed high voltage, and pulse frequency, the decrease of the diameter of catalyst particles and the thickness of catalyst bed. Finally, a model was established to predict the degradation of the rogor, which generally can simulate the experimental measurements to some degree.

Influence Parameters in the Ozonation of Clofibric Acid Using a Cascade Bubble Column

2012 ◽  
Vol 573-574 ◽  
pp. 538-541
Author(s):  
Yan Ping Duan ◽  
Sven Geissen ◽  
Ling Chen
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Gas Flow ◽  
Liquid Flow Rate ◽  
Bubble Column ◽  
Continuous Operation ◽  
Clofibric Acid ◽  
Gas Flow Rate ◽  
Toc Removal ◽  
Operation Parameters

Ozonation of clofibric acid (CA) in aqueous solution was carried out under continuous operation in a cascade bubble column. The influence of operation parameters including initial CA concentration, gas flow rate, liquid flow rate and pH on the removal of CA and TOC was investigated. The results indicated that ozonation could be used to effectively remove CA from water. Increasing the initial CA concentration resulted in a decrease of the CA and TOC removal efficiency. A comparison of CA removal efficiency and ozone utilization between cascade and conventional bubble column indicated that cascade bubble column was an effective way for increasing the solubility ozone in the reactor.

The Effect of Water-Vapor Content and Gas Flow Rate on the Oxidation Mechanism of a 10%Cr-Ferritic Steel in Ar-H2O Mixtures

2005 ◽  
Vol 63 (5-6) ◽  
pp. 401-422 ◽  
Author(s):  
J. Żurek ◽  
M. Michalik ◽  
F. Schmitz ◽  
T. -U. Kern ◽  
L. Singheiser ◽  
...  
Keyword(s):  
Water Vapor ◽  
Flow Rate ◽  
Ferritic Steel ◽  
Gas Flow ◽  
Oxidation Mechanism ◽  
Water Vapor Content ◽  
Gas Flow Rate ◽  
Effect Of Water

scholarly journals The Effect of Mass Transfer Rate-Time in Bubbles on Removal of Azoxystrobin in Water by Micro-Sized Jet Array Discharge

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1169
Author(s):  
Feng Chen ◽  
Dezheng Yang ◽  
Feng Yu ◽  
Yang Kun ◽  
Ying Song
Keyword(s):  
Mass Transfer ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Applied Voltage ◽  
Transfer Rate ◽  
Gas Flow ◽  
Mass Transfer Rate ◽  
Initial Solution ◽  
Solution Temperature ◽  
Gas Flow Rate

In this work, the azoxystrobin removal in water by using a micro-size discharge array was investigated, and the removal efficiency can reach as high as 98.1% after 9 min plasma treatment as well as the energy utilization being only 0.73 g/(kW·h). Based on the relationship between the generation of gas bubbles and parameters of gas-liquid discharge, it was found that the variation of applied voltage, gas flow rate and initial solution temperature could cause particle number change, mass transfer rate change and the mass transfer time change, which significantly affected the practical applications at last. The experimental results indicated that when gas flow rate was 0.7 SLM (Standard Liter per Minute) and the initial solution temperature was 297 K with the applied voltage of 8 kV and discharge frequency of 6 kHz, the removal efficiency of azoxystrobin achieved maximum. Based on the analysis results of liquid mass spectrometry, the removal pathways of azoxystrobin were supposed by the decomposed by-products. Toxicity tests indicated that the decomposed products were safe and non-toxic. So, this study may reveal an azoxystrobin degradation mechanism and provide a safe, reliable and effective way for azoxystrobin degradation.

Degradation of Silicon Carbide in Combustion Gas Flow at High-Temperature and Speed

2000 ◽  
Author(s):  
I. Yuri ◽  
T. Hisamatsu ◽  
Y. Etori ◽  
T. Yamamoto
Keyword(s):  
Silicon Carbide ◽  
Weight Loss ◽  
Water Vapor ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Flow Rate ◽  
Gas Flow ◽  
Gas Flow Rate ◽  
Vapor Partial Pressure ◽  
Water Vapor Partial Pressure

Effects of various basic factors of combustion gas flow conditions on degradation behaviors of silicon carbide have been experimentally determined. The exposure tests were performed for widely varied experimental parameters of the gas temperatures (T = 900–1500°C), pressure (P = 0.3–0.8MPa), gas flow rate (V = 50–250m/s), water vapor partial pressure (PH2O = 32–82kPa) and oxygen partial pressure (PO2 = 24–44kPa). Degradation behaviors of silicon carbide were expressed as the weight loss of the substrate. The weight loss rate depends on the water vapor partial pressure remarkably. The effect of the oxygen partial pressure on the weight loss was smaller than that of the water vapor partial pressure, and the weight loss decreased with the increase of the oxygen partial pressure. Considering the effects of partial pressures of oxygen and water vapor, the gas temperature and the pressure didn’t have much effect on the weight loss. The weight loss depends on the gas flow rate, the increase rate of the weight loss for the gas flow rate becomes small with the gas flow rate. Consequently, the water vapor partial pressure, the oxygen partial pressure, the gas temperature, the pressure and the gas flow rate dependence of the weight loss rate is expressed as PH2O1.9 V0.6 P0.3 / PO20.6.

Removal of Toluene by Dielectric Barrier Discharge Combined with Modified Photocatalyst

2015 ◽  
Vol 737 ◽  
pp. 561-564
Author(s):  
Jing Xin Li ◽  
Bao Hui Li ◽  
Zhi Yong Li
Keyword(s):  
Energy Efficiency ◽  
Dielectric Barrier Discharge ◽  
Flow Rate ◽  
Gas Flow ◽  
Barrier Discharge ◽  
Gas Flow Rate ◽  
Dielectric Barrier ◽  
Optimal Doping ◽  
Initial Concentration ◽  
Doping Ratio

The toluene being removed by dielectric barrier discharge (DBD) combined with modified photocatalyst was studied in the paper. Transition metal manganese was doped into crystal lattice of TiO2 in order to improve the activity of photocatalyst, and the optimal doping ratio was confirmed in the study. As one of main factors, the influence on toluene removal efficiency of gas flow rate, initial concentration and electric field intensity was analyzed in the study. Furthermore, the energy efficiency was another important index which had been compared amongγ-Al2O3, TiO2/γ-Al2O3 and Mn-TiO2/γ-Al2O3. The result of study showed that DBD combined with Mn-TiO2/γ-Al2O3 had the best buffer action against increasing of gas flow rate and initial concentration, the energy efficiency had the tendency as Mn-TiO2/γ-Al2O3 > TiO2/γ-Al2O3>γ-Al2O3, and the optimal doping ratio of manganese was 0.01.

Evaluation of NOX Removal from Simulated Flue Gas by "Absorption-Oxidation-Reduction" Method

2014 ◽  
Vol 884-885 ◽  
pp. 261-265
Author(s):  
Bao Lin Li ◽  
Ming Yu Li ◽  
Hai Hao Liu ◽  
Gang Cao ◽  
Gang Ren ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Flue Gas ◽  
Ferrous Sulfate ◽  
Gas Flow ◽  
Reduction Method ◽  
Ph Value ◽  
Sulfate Solution ◽  
Gas Flow Rate ◽  
Oxidation Reduction

This paper presented a new method of absorption-oxidation-reduction which used ferrous sulfate solution as absorbent, oxygen as oxidizer and urea as reducer to remove NOX from flue gas based on the properties of Fe2+, NO, [Fe (NO)]2+ and urea. These properties included that Fe2+ and NO could produce [Fe (NO)]2+, furthermore [Fe (NO)]2+ was easy to be oxidized by O2, as well as urea can reduce HNO2 and HNO3 in the absorption liquid. This research was to discuss its absorption and removal mechanism with the influence of the initial urea concentration, pH value, initial NOX concentration and gas flow rate on the NOX removal efficiency. The results showed that the removal efficiency of NOX would increase when the initial concentration of urea and NOX increased, while the pH value and gas flow rate decreased.

Study of Toluene Removal by Bipolar Corona Discharge Coupled with Photocatalytic

2014 ◽  
Vol 955-959 ◽  
pp. 2357-2361
Author(s):  
Hai Feng Chen
Keyword(s):  
Corona Discharge ◽  
Removal Efficiency ◽  
Gas Flow ◽  
Coupling Effect ◽  
Degradation Efficiency ◽  
Gas Flow Rate ◽  
Initial Concentration ◽  
Toluene Removal ◽  
Optimized Conditions ◽  
Important Significance

Experimental study the degradation efficiency of toluene by bipolar corona discharge coupled with TiO2 photocatalysis. Bipolar corona discharge can degrade the toluene efficiently and rapidly, the final products are mainly carbon dioxide and water. Toluene removal efficiency reduces when the initial concentration of toluene increasing, while toluene removal quantity is increased. Removal of toluene decreases with the gas flow rate increasing, the removal quantity first increases and then decreases. Bipolar corona discharge and a photocatalytic coupling can inprove the degradation efficiency further. Increase of the applied voltage help to improve the removal of toluene, and also to improve the coupling effect of the photocatalyst. In optimized conditions, the removal efficiency of toluene can be more than 90%. The chemical reaction process of the toluene oxidation and the TiO2 catalysis mechanism are discussed. It is pointed out that the OH* produced by corona discharge has important significance for rapid oxidation of toluene.

scholarly journals Simultaneous removal efficiency of H2S and CO2 by high-gravity rotating packed bed: Experiments and simulation

2021 ◽  
Vol 19 (1) ◽  
pp. 288-298
Author(s):  
Lien Thi Tran ◽  
Tuan Minh Le ◽  
Tuan Minh Nguyen ◽  
Quoc Toan Tran ◽  
Xuan Duy Le ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Gas Flow ◽  
Liquid Flow Rate ◽  
Packed Bed ◽  
High Gravity ◽  
Gas Flow Rate ◽  
Solution Ph ◽  
Rotating Speed ◽  
Rotating Packed Bed

Abstract This study explores the possibility of applying high-gravity rotating packed bed (HGRPB) in removing H2S and CO2 from biogas. Ca(OH)2 aqueous solution was used as the absorbent in this study. Different experimental conditions including solution pH, rotating speed (R S) of HGRPB, gas flow rate (Q G), and liquid flow rate (Q L) were investigated with respect to the removal efficiency (E) of H2S and CO2. The experimental and simulated results show that the optimal removal efficiency of H2S and CO2 using HGRPB achieved nearly the same as 99.38 and 99.56% for removal efficiency of H2S and 77.28 and 77.86% for removal efficiency of CO2, respectively. Such efficiencies corresponded with the following optimal conditions: a solution pH of 12.26, HGRPB reactor with the rotating speed of 1,200 rpm, the gas flow rate of 2.46 (L/min), and the liquid flow rate of 0.134 (L/min).

Plasma degradation of trichloroethylene: Process optimization and reaction mechanism analysis

2021 ◽  
Author(s):  
Tian Chang ◽  
Chuanlong Ma ◽  
Anton Yu Nikiforov ◽  
Savita K.P. Veerapandian ◽  
Nathalie De Geyter ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Gas Flow ◽  
Discharge Power ◽  
Mechanism Analysis ◽  
Gas Flow Rate ◽  
Chlorinated Volatile Organic Compounds ◽  
Volatile Organic ◽  
Process Factors ◽  
Decomposition Pathway

Abstract In this study, a multi-pin-to-plate negative glow discharge reactor was employed to degrade the hazardous compound, trichloroethylene (TCE). The response surface methodology (RSM) was applied to examine the influences of various process factors (relative humidity (RH), gas flow rate, and discharge power) on the TCE decomposition process, with regard to the TCE removal efficiency, CO2 and CO selectivities. The variance analysis was used to estimate the significance of the single process factors and their interactions. It has been proved that the discharge power had the utmost influential impact on the TCE removal efficiency, CO2 and CO selectivities, subsequently the gas flow rate, and finally RH. Under the optimal conditions with 20.83% RH, 2 W discharge power and 0.5 L·min–1 gas flow rate, the optimal TCE removal efficiency (86.05%), CO2 selectivity (8.62%), and CO selectivity (15.14%) were achieved. In addition, a possible TCE decomposition pathway was proposed based on the investigation of byproducts identified in the exhaust gas of the NTP reactor. This work paves a way for the control of chlorinated volatile organic compounds.

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