Effect of flow rate, draw solution concentration and temperature on the performance of TFC FO membrane, and the potential use of RO reject brine as a draw solution in FO-RO hybrid systems

2018 ◽  
Vol 136 ◽  
pp. 65-71 ◽  
Author(s):  
Nawshad Akther ◽  
Sahar Daer ◽  
Shadi W. Hasan
Keyword(s):  
Hybrid Systems ◽  
Flow Rate ◽  
Solution Concentration ◽  
Draw Solution ◽  
Potential Use

scholarly journals Comparative Study for Organic and Inorganic Draw Solutions in Forward Osmosis

2017 ◽  
Vol 13 (1) ◽  
pp. 94-102
Author(s):  
Ahmed Faiq Al-Alalawy ◽  
Talib Rashid Abbas ◽  
Hadeer Kadhim Mohammed
Keyword(s):  
Flow Rate ◽  
Water Flux ◽  
Forward Osmosis ◽  
Solution Concentration ◽  
Salt Flux ◽  
Effect Of Temperature ◽  
Solution Flow Rate ◽  
Solution Flow ◽  
Draw Solution ◽  
Reverse Salt Flux

The present work aims to study forward osmosis process using different kinds of draw solutions and membranes. Three types of draw solutions (sodium chloride, sodium formate, and sodium acetate) were used in forward osmosis process to evaluate their effectiveness with respect to water flux and reverse salt flux. Experiments conducted in a laboratory-scale forward osmosis (FO) unit in cross flow flat sheet membrane cell.  Three types of membranes (Thin film composite (TFC), Cellulose acetate (CA), and Cellulose triacetate (CTA)) were used to determine the water flux under osmotic pressure as a driving force. The effect of temperature, draw solution concentration, feed and draw solution flow rate, and membrane types, were studied with respect to water flux. The results showed an increase in water flux with increasing feed temperature and draw solution concentrations In addition, the flux increased with increasing feed flow rate while the flux was inversely proportional with the draw solution flow rate. The results showed that reverse osmosis membranes (TFC and CA) are not suitable for using in FO process due to the relatively obtained low water flux when compared with the flux obtained by forward osmosis membrane (CTA). NaCl draw solution gave higher water flux than other draw solutions and at the same time, revealed higher reverse salt flux.

Research on Electrospinning Process of Pullulan Nanofibers

2012 ◽  
Vol 268-270 ◽  
pp. 198-201 ◽  
Author(s):  
Xiao Bin Sun ◽  
D. Jia ◽  
Wei Min Kang ◽  
Bo Wen Cheng ◽  
Ya Bin Li
Keyword(s):  
Flow Rate ◽  
Applied Voltage ◽  
Great Influence ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Diameter Distribution ◽  
Optimal Parameters ◽  
Redistilled Water ◽  
Water As Solvent

A kind of pullulan biopolymer nanofibers with diameter of 100～700nm were obtained using redistilled water as solvent through electrospinning technology in this paper. The effects of the spinning solution concentration, applied voltage, flow rate and capillary–screen distance on morphology and diameter distribution of pullulan nanofiber were studied by SEM. The results show that, different parameters had great influence on nanofibers’ morphology and diameter. The optimal parameters of pullulan nanofibers electrospinning were: 22wt.% spinning solution concentration, 31 kV voltage, 20 cm capillary–screen distance and 0.5ml/h flow rate.

scholarly journals Neutralization Dialysis for Phenylalanine and Mineral Salt Separation. Simple Theory and Experiment

Membranes ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 171 ◽  
Author(s):  
Anton Kozmai ◽  
Elena Goleva ◽  
Vera Vasil’eva ◽  
Victor Nikonenko ◽  
Natalia Pismenskaya
Keyword(s):  
Amino Acid ◽  
Flow Rate ◽  
Solution Concentration ◽  
Exchange Capacity ◽  
Ion Concentration ◽  
Solution Flow Rate ◽  
Strong Electrolyte ◽  
Mineral Salts ◽  
Solution Flow ◽  
Hydrodynamic Mode

A simple non-steady state mathematical model is proposed for the process of purification of an amino acid solution from mineral salts by the method of neutralization dialysis (ND), carried out in a circulating hydrodynamic mode. The model takes into account the characteristics of membranes (thickness, exchange capacity and electric conductivity) and solution (concentration and components nature) as well as the solution flow rate in dialyzer compartments. In contrast to the known models, the new model considers a local change in the ion concentration in membranes and the adjacent diffusion layers. In addition, the model takes into consideration the ability of the amino acid to enter the protonation/deprotonation reactions. A comparison of the results of simulations with experimental data allows us to conclude that the model adequately describes the ND of a strong electrolyte (NaCl) and amino acid (phenylalanine) mixture solutions in the case where the diffusion ability of amino acids in membranes is much less, than mineral salts. An example shows the application of the model to predict the fluxes of salt ions through ion exchange membranes as well as pH of the desalination solution at a higher than in experiments flow rate of solutions in ND dialyzer compartments.

Removal of nitrate using activated carbon-based electrodes for capacitive deionization

2018 ◽  
Vol 18 (6) ◽  
pp. 2028-2034 ◽  
Author(s):  
Shaojie Jiang ◽  
Hongwu Wang ◽  
Guanquan Xiong ◽  
Xinlei Wang ◽  
Siying Tan
Keyword(s):  
Activated Carbon ◽  
Phosphoric Acid ◽  
Flow Rate ◽  
Nitrate Removal ◽  
Cell Voltage ◽  
Solution Concentration ◽  
Capacitive Deionization ◽  
Optimal Conditions ◽  
Ion Removal ◽  
Initial Solution Concentration

Abstract The removal performance of nitrate using capacitive deionization (CDI) of activated carbon (AC)-based electrodes were studied. The AC electrode was prepared and the effect of cell voltage, flow rate and initial solution concentration on ion removal were investigated. Furthermore, the AC was modified with phosphoric acid (ACP) and the surface structure of AC and ACP were analyzed. The results showed that the specific surface area of AC increased by 10.71% after the modification. The mesopore ratio and micropore ratio increased by 14.69% and 24.06%, respectively. The optimal conditions of AC electrode was a voltage of 1.4 V and flow rate of 20 mL/min while the ACP electrode was a voltage of 1.4 V and flow rate of 10 mL/min. The electrosorption capacity of ACP electrode was improved and the unit of electrosorption load was high to 19.28 mg/L. For the AC or ACP electrode, the nitrate removal efficiency decreases with the increase in the initial feed solutions, but the unit electrosorption load gradually increased with the improvement of initial feed solutions' concentration and the ACP electrode was superior to the AC electrode. Therefore, the ACP electrode would be suitable for the application of CDI on the nitrate removal.

scholarly journals Preparation of electrospun nanofiber membrane for air filtration and process optimization based on BP neural network

2021 ◽  
Author(s):  
Le Kang ◽  
Yuankun Liu ◽  
Liping Wang ◽  
Xiaoping Gao
Keyword(s):  
Neural Network ◽  
Quality Factor ◽  
Flow Rate ◽  
Bp Neural Network ◽  
Polyvinylidene Fluoride ◽  
Orthogonal Experiment ◽  
Solution Concentration ◽  
Filtration Efficiency ◽  
Air Filtration ◽  
Filtration Resistance

Abstract The filtration layer in a medical protective mask can effectively prevent aerosol particles that might carry viruses from air. A nanofiber/microfiber composite membrane (NMCM) was successfully fabricated by electrospinning polyvinylidene fluoride (PVDF) nanofibers collected on the electrified and melt-blown polypropylene (PP) nonwovens, aiming to improve the filtration efficiency and reduce the resistance of respiration of mask. A four-factor and three-level orthogonal experiment was designed to study the effect of electrospinning parameters such as spinning solution concentration, voltage, tip-collect distance (TCD), and flow rate of solution on the filtration efficiency, resistance of respiration as well as quality factor of NMC developed to predict the resistance of respiration. Experimental results demonstrated that the filtration efficiency of NMCM≥95% in comparison to that of electrified and melt-blown PP nonwovens 79.38%, which increases by 19.68%. Additionally, the average resistance of respiration is 94.78 Pa, which meets the protection requirements. Multivariate analysis of variance indicated that the resistance of respiration of the NMCM has significantly dependent on the concentration, voltage, TCD, and flow rate of the spinning solution and the quality factor of the NMCM has dependent on the resistance of respiration. The air permeability ranges from 166.23 to 314.35mm/s, which is inversely proportional to the filtration resistance. As far as the filtration resistance is concerned, the optimal spinning parameters were obtained as follows. The concentration of spinning solution is 15%, the voltage is 27 kV, the TCD is 22 cm, and the flow rate is 2.5 mL/h. The relative error of the BP neural network varies from 0.49505% to 1.49217%, i.e. the error value varies from 0.17 to1.33 Pa. The predicted resistance of respiration corresponding to the optimal process is 68.1374 Pa.

scholarly journals Analysis of the Process Parameters for Obtaining a Stable Electrospun Process in Different Composition Epoxy/Poly ε-Caprolactone Blends with Shape Memory Properties

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 475 ◽  
Author(s):  
Alvaro Iregui ◽  
Lourdes Irusta ◽  
Loli Martin ◽  
Alba González
Keyword(s):  
Shape Memory ◽  
Flow Rate ◽  
Composition Dependence ◽  
Fiber Diameter ◽  
Stable Process ◽  
Solution Concentration ◽  
Diglycidyl Ether ◽  
Process Variables ◽  
Shape Memory Properties

In this work Poly ε-caprolactone (PCL)/ Diglycidyl ether of bisphenol A (DGEBA) blends were electrospun and the obtained mats were UV cured to achieve shape memory properties. In the majority of studies, when blends with different compositions are electrospun, the process variables such as voltage or flow rate are fixed independently of the composition and consequently the quality of the fibers is not optimized in all of the range studied. In the present work, using the design of experiments methodology, flow rate and voltage required to obtain a stable process were evaluated as responses in addition to the fiber diameter and shape memory properties. The results showed that the solution concentration and amount of PCL played an important role in the voltage and flow rate. For the shape memory properties excellent values were achieved and no composition dependence was observed. In the case of fiber diameter, similar results to previous works were observed.

Investigation of the power generation performance of a stack by reverse electrodialysis and its influencing factors

2021 ◽  
pp. 1-9
Author(s):  
Mei Li ◽  
Yiwei Wang ◽  
Jiabin Guo ◽  
Xiaoliang Li ◽  
Pengcheng Guo
Keyword(s):  
Power Generation ◽  
Flow Rate ◽  
Power Output ◽  
Concentration Polarization ◽  
Solution Concentration ◽  
Generation Process ◽  
Cell Pair ◽  
Ohmic Resistance ◽  
Pair Number ◽  
Membrane Type

Abstract This paper presents an experimental study on the performance of a RED stack for SELEMION, ASTOM and FUJI membranes with the cell pair number from 3 to 15 and flow rate from 5 to 60 L/h over a wide solution concentration range from 1 to 120 g/L. DC and AC measurements are employed to identify quantatively the contribution of ohmic and non-ohmic resistances to the stack resistance and then, the power output is predicted theoretically. The results show that the ohmic resistance dominates in the stack resistance and accounts for about 90%. The factors such as the membrane type, cell pair, solution concentration and flow rate have a considerable impact on power generation process of RED. Especially, simultaneous increasing the HC and LC solution concentrations is more conducive to suppressing the concentration polarization when compared with increasing LC solution concentration alone. Although the concentration polarization maintains declining with the increase in flow rate, the flow rate should not be too large in order to harvest the highest power output by reason of serious tangential flow at higher flow rates. The optimal performance of RED stack is obtained when SELEMION membranes are used with cell pairs of 5, HC-LC solution concentration of 120-4 g/L and feed flow rate of 20 L/h.

Preparation of Ethyl-Cellulose Nanofibers via An Electrospinning

2007 ◽  
Vol 119 ◽  
pp. 255-258 ◽  
Author(s):  
Joon Pyo Jeun ◽  
Youn Mook Lim ◽  
Jae Hak Choi ◽  
Hyun Shil La ◽  
Phil Hyun Kang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Flow Rate ◽  
Ethyl Cellulose ◽  
Cellulose Nanofibers ◽  
Solution Concentration ◽  
Fiber Morphology ◽  
Electric Voltage ◽  
Scanning Electron

Ethyl-cellulose (EC) nanofibers were fabricated by an electrospinning of an EC solution with a 6-12 wt% concentration. Fiber morphology was observed under a scanning electron microscope and the effects of instrument parameters including the solution concentration, flow rate and electric voltage were investigated.

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