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 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.

scholarly journals TOTAL VOLUMETRIC MASS TRANSFER COEFFICIENT AT CO2 GAS ABSORPTION USING K2CO3 BY MSG PROMOTER

Konversi ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Erlinda Ningsih ◽  
Abas Sato ◽  
Mochammad Alfan Nafiuddin ◽  
Wisnu Setyo Putranto
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Liquid Flow ◽  
Total Mass ◽  
Gas Flow ◽  
Liquid Flow Rate ◽  
Gas Flow Rate ◽  
Co2 Gas

Abstract- One of the most widely used processes for CO2 gas removal is Absorption. Carbon dioxide is the result of the fuel combustion process which of the hazardous gases. The aim of this research is to determine the total mass transfer coefficient and analyze the effect of the absorbent flow rate of the absorbent solution with the promoter and the gas flow rate to the total mass transfer coefficient value. The variables consisted of liquid flow rate: 1, 2, 3, 4, 5 liter/min, gas flow rate: 15, 25, 30, 40, 50 liter/min and MSG concentration: 0%, 1%, 3% and 5% by weight. The solution of Pottasium Carbonate as absorbent with MSG promoter is flowed through top column and CO2 gas flowed from bottom packed column. Liquids were analyzed by titration and the gas output was analyzed by GC. From this research, it is found that the flow rate of gas and the liquid flow rate is directly proportional to the value of KGa. The liquid flow rate variable 5 liters / minute, gas flow rate 15 l / min obtained value of KGa 11,1102 at concentration of MSG 5%. Keywords:  Absorption, CO2,  K2CO3, MSG. 

scholarly journals NO Separation Characteristics in Integrated Electromigration Membrane Reactor

2020 ◽  
Vol 10 (15) ◽  
pp. 5071
Author(s):  
Zuwu Wang ◽  
Guifen Shen
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Total Mass ◽  
Membrane Reactor ◽  
Gas Flow ◽  
Separation Efficiency ◽  
Discharge Voltage ◽  
Gas Flow Rate

An integrated electromigration membrane absorption method has been proposed for the separation of NO from simulated mixed gas. The experiments were conducted to investigate the effect of discharge voltage, gas flow rate, inlet concentrations, and absorbents on the NO separation efficiency and total mass transfer coefficient in the integrated electromigration membrane reactor. The experimental results demonstrated that the NO separation efficiency and total mass transfer coefficient increased with the increase in the applied discharge voltage of the integrated electromigration membrane reactor. Regardless of discharge or not, the separation efficiency of NO continuously decreased with the increase in the gas flow rate and inlet concentration of NO in the experimental process. The total mass transfer coefficient of NO increased first and then decreased with an increase in the gas flow rate, while it decreased with an increase in NO inlet concentration. Compared with the membrane absorption without discharge voltage under the condition tested, at a discharge voltage of 18kV, the NO separation efficiency and the total mass transfer coefficient increased by 48.7% and 9.7 times, respectively.

Direct molecular hydrogen sulphide scrubbing with hollow fibre membranes

2001 ◽  
Vol 44 (9) ◽  
pp. 135-142 ◽  
Author(s):  
N. Boucil ◽  
B. Jefferson ◽  
S.A. Parsons ◽  
S.J. Judd ◽  
R.M. Stuetz
Keyword(s):  
Mass Transfer ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Flow Rate ◽  
Hydrogen Sulphide ◽  
Gas Flow ◽  
Hollow Fibre ◽  
The Other ◽  
Gas Flow Rate

The emission of hydrogen sulphide is a major problem associated with anaerobic treatment of sulphate and sulphite containing wastewaters. Conventional absorbing processes, such as packed towers, spray towers or bubble columns, are all constrained by factors such as flooding and foaming. Membrane systems, on the other hand, enable independent control of the liquid and gas flow rate and a step change order of magnitude increase in the specific surface area of the contact process. The membrane acts as a gas absorber with a design similar to a shell and tube heat exchanger. On the other hand, they are limited by facets of the membrane such as its resistance to mass transfer and permselectivity, as well as its cost. The work presented in this paper refers to an absorption process based on a non-wetted hollow fibre membrane for the scrubbing of hydrogen sulphide from air, with water as the contact solvent. Results presented describe the performance of the unit in terms of overall transfer and outlet liquid concentration as a function of circulation regime, gas flow rate, liquid flow rate and specific surface area. In particular, results are presented using traditional plots of Sherwood number (Sh) against Graetz (Gr) number for the liquid flowing in the lumens, such that experimental and available empirical descriptions of the process performance are directly compared. Results suggest that, as expected, very efficient mass transfer is obtained. However, the mass transfer was found to reach a maximum value against Gr, contrary to available empirical models.

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.

Effect of Gas Flow Rate on Degradation of 2,4-D with O3 and O3/H2O2

2012 ◽  
Vol 433-440 ◽  
pp. 221-226
Author(s):  
Lan Chen ◽  
Yu Heng Quan
Keyword(s):  
Hydrogen Peroxide ◽  
Mass Transfer ◽  
Production Rate ◽  
Flow Rate ◽  
Gas Flow ◽  
Batch Reactor ◽  
Gas Flow Rate ◽  
Transfer Condition ◽  
Flow Rates ◽  
2,4 Dichlorophenoxyacetic Acid

The effect of gas flow rate on degradation of chlorinated phenoxy acetic acids herbicide 2,4-D(2,4-dichlorophenoxyacetic acid) in aqueous solution with O3 or O 3/H 2O2 process was investigated in a bubbling semi-batch reactor. The experiments were conducted to study the degradation rate constant, mass transfer condition, ozone consumption and formation of byproduct hydrogen peroxide at different gas flow rates. The results show that gas flow rate is a complicated parameter in the process. The contact time of gas and liquid phase varies with different gas flow rate, consequently ozone mass transfer condition changes with different gas flow rates. The production rate of ozone, amount of ozone in the end gas and ozone consumption during the degradation with ozonation and O 3/H2O2 process vary with different of gas flow rates. Hydrogen peroxide is a byproduct during the ozonation or O3/H2O2 process of 2,4-D. The production rate of hydrogen peroxide is also affected by the gas flow rate. In general gas flow rate has both positive and negative effect on the 2,4-D degradation.

scholarly journals Mass transfer parameters in spray columns: 2. The system benzene-wash oil

1989 ◽  
Vol 8 (2) ◽  
pp. 63-68
Author(s):  
A. J. Rautenbach ◽  
G. Kornelius
Keyword(s):  
Mass Transfer ◽  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Unit Volume ◽  
Liquid Flow Rate ◽  
Column Height ◽  
Gas Flow Rate ◽  
Side Resistance ◽  
Transfer Parameters

Spray columns are widely used in industry as a gas-liquid contacting apparatus because of the advantages of a high transfer area per unit volume and the tow gas side resistance. For a large number of systems, mass transfer parameters are not available and an experimental determination for the system benzene/wash oil was therefore carried out. The experimental technique and design are described. The variation in mass transfer coefficient as function of gas flow rate, liquid flow rate and column height agrees with those published elsewhere.

OPTIMIZATION OF NON THERMAL PLASMA REACTOR PERFORMANCE FOR THE DECOMPOSITION OF XYLENE

2016 ◽  
Vol 78 (8) ◽  
Author(s):  
Nor Faraliana Shazwani Nor Azmi ◽  
Abdullahi Mohammed Evuti ◽  
Mohd Ariffin Abu Hassan ◽  
R. K. Raja Ibrahim
Keyword(s):  
Flow Rate ◽  
Thermal Plasma ◽  
Applied Voltage ◽  
Gas Flow ◽  
Plasma Reactor ◽  
Gas Flow Rate ◽  
Reactor Performance ◽  
Model Predictions ◽  
Non Thermal Plasma ◽  
Discharge Gap

Non Thermal Plasma (NTP) is an emerging method used for the decomposition of volatile organic compounds (VOCs). This research focuses on the optimization of NTP reactor performance for decomposition of xylene from wastewater using response surface methodology (RSM) by operating the NTP reactor at applied voltage of 12-15 kV, discharge gap of 2.0-3.0 cm and gas flow rate of 2.0-5.0 L/min. An optimum xylene removal efficiency of 81.98% was obtained at applied voltage 15kV, discharge gap 2.09cm and gas flow rate at 2.36 L/min. The experimental removal efficiencies and model predictions were in close agreement with an error of 0.63%. 

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