A unified thermodynamic fouling mechanism based on forward osmosis membrane unique properties: An asymmetric structure and reverse solute diffusion

2021 ◽  
pp. 152219
Author(s):  
Jiaheng Teng ◽  
Hanmin Zhang ◽  
Hongjun Lin ◽  
Fangang Meng
Keyword(s):  
Forward Osmosis ◽  
Solute Diffusion ◽  
Asymmetric Structure ◽  
Fouling Mechanism

Quantifying the influence of divalent cations mass transport on critical flux and organic fouling mechanism of forward osmosis membrane

Desalination ◽  
2021 ◽  
Vol 512 ◽  
pp. 115146
Author(s):  
Thanh-Tin Nguyen ◽  
Rusnang Syamsul Adha ◽  
Chulmin Lee ◽  
Dong-Ho Kim ◽  
In S. Kim
Keyword(s):  
Mass Transport ◽  
Divalent Cations ◽  
Forward Osmosis ◽  
Critical Flux ◽  
Fouling Mechanism ◽  
Organic Fouling

scholarly journals Performance of layer-by-layer (LbL) polyelectrolyte forward osmosis membrane for humic acid removal and reverse solute diffusion

2017 ◽  
Vol 19 ◽  
pp. 75 ◽  
Author(s):  
Suriani Husaini ◽  
Mazrul Nizam Abu Seman
Keyword(s):  
Humic Acid ◽  
Chemical Engineering ◽  
Water Flux ◽  
Forward Osmosis ◽  
Feed Solution ◽  
Solute Diffusion ◽  
Membrane Properties ◽  
Layer By Layer ◽  
Engineering Research ◽  
Draw Solution

<p>Recent study claimed that forward osmosis (FO) process could handle the fouling problem due it driven force based on natural osmotic pressure. However, researchers observed that FO membrane had problem with reverse solute diffusion (RSD) of draw solution. Therefore, FO membrane properties must be improved either physically or chemically in order to overcome this problem. Among all, surface modification approach has been acknowledged as a best technique to alter the membrane properties without significantly change the bulk membrane properties. In this study, polyelectrolyte FO membrane has been produced through Layer by Layer (LbL) deposition method by using Poly (diallyl-dimethylammoniumchloride), PDADMAC and Poly (sodium 4-styrene-sulfonate), PSS as an active monomers. Humic acid (HA) as part of Natural Organic Matter constituents was used as the feed solution and NaCl as a draw solution. The chemical structure and morphology of the FO membrane were characterized by FTIR and FESEM, respectively. From this study, the highest water flux and humic acid rejection were achieved at 2.5M of draw solution with value of 2.56 L/m<sup>²</sup>.h and 99%, respectively. In general, the water flux increases as the concentration of draw solutions were increased. However, it was observed that reverse salt diffusion (RSD) become worse at higher concentration of draw solution.</p><p>Chemical Engineering Research Bulletin 19(2017) 75-79</p>

Fabrication of PSS/PDADMAC Polyelectrolyte Membrane via Layer-by-Layer (LbL) Technique for Forward Osmosis (FO) Application

2019 ◽  
Vol 797 ◽  
pp. 13-19
Author(s):  
Mok Tze How ◽  
Mazrul Nizam Abu Seman
Keyword(s):  
Deposition Time ◽  
Pure Water ◽  
Water Flux ◽  
Forward Osmosis ◽  
Solute Diffusion ◽  
Layer By Layer ◽  
Styrene Sulfonate ◽  
Membrane Performance ◽  
Coated Layer ◽  
Polyelectrolyte Membrane

In this study, FO membrane was fabricated by Layer-by-Layer (LbL) coating technique using Poly (sodium 4-styrene-sulfonate)(PSS) and Poly (diallyl-dimethylammoniumchloride) (PDADMAC) as the active polyelectrolytes. Different concentrations of polyelectrolytes and deposition time of polyelectrolytes were investigated. The success of the coated layer was confirmed using ATR-FTIR and FESEM images. The membrane performance was determined by water flux and reverse solute diffusion (RSD) using pure water and 1.75M Na2SO4 as feed and draw solution, respectively. It was observed that the highest water flux, 6.76 L/ was recorded at the lowest polyelectrolytes concentration and longer deposition time. Meanwhile, the minimum RSD was achieved by the membrane fabricated at the longest deposition time and highest polyelectrolyte concentration.

scholarly journals Membrane Fouling – The Enemy of Forward Osmosis

2021 ◽  
Vol 25 (2) ◽  
pp. 73-88
Author(s):  
Z. H. Chang ◽  
Y. H. Teow ◽  
S. P. Yeap ◽  
J. Y. Sum
Keyword(s):  
Membrane Fouling ◽  
Membrane Separation ◽  
Membrane Surface ◽  
Forward Osmosis ◽  
Feed Solution ◽  
Separation Process ◽  
Nutrient Recovery ◽  
Water Reclamation ◽  
Water Permeation ◽  
Fouling Mechanism

Forward osmosis (FO) is an osmotically driven membrane separation process. It is potentially applied in various industries for nutrient recovery and water reclamation. Although FO showed a lesser fouling tendency than other pressure-driven membrane processes, the solutes in the feed solution would still deposit on the membrane surface, forming a fouling layer that resists water permeation. For that reason, fouling mitigation is a trending issue in the FO process. A better understanding of the fouling mechanism is required before opting for the appropriate strategy to mitigate it. This article describes the fouling mechanism based on different foulant presented in the feed, followed by a method in relieving fouling in the FO process.

scholarly journals Optimization of Operating Conditions in Forward Osmosis for Osmotic Membrane Bioreactor

2009 ◽  
Vol 3 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Jian-Jun Qin ◽  
Maung Htun Oo ◽  
Guihe Tao ◽  
E. R. Cornelissen ◽  
C. J. Ruiken ◽  
...  
Keyword(s):  
Flow Pattern ◽  
Membrane Bioreactor ◽  
Concentration Polarization ◽  
Forward Osmosis ◽  
Operating Conditions ◽  
Solute Diffusion ◽  
External Concentration ◽  
Selective Layer ◽  
Draw Solution ◽  
Osmotic Membrane Bioreactor

Objective of this study was to conduct a baseline study of osmotic membrane bioreactor (OMBR) - optimization of operating conditions in forward osmosis (FO). Experiments were conducted with an FO pilot system. Tap water was used as the feed and NaCl and MgSO4 solutions were used as draw solution. Effects of various operating conditions on flux have been investigated. In addition, pure water permeability of the FO membrane was tested. It was observed that the plant operation could be stablized within 1 h. When the membrane selective layer faced to the feed, a flux of 6.3 lm-2h-1 (LMH) was achieved at 24 atm osmotic pressure and 25 °C and effects of feed velocity and air velocity on flux were not siganificant under the testing conditions due to low external concentration polarization (ECP). However, when the selective layer faced to the draw solution, the flux was enhanced by 64% due to much reduced internal concentration polarization (ICP), the flux sharply increased with an increase in velocity of the draw solution in the laminar flow pattern range due to a countable effect of dilutive external concentration polarization (DECP) and leveled off after the flow pattern became turbulent. NaCl performed much higher efficiency than MgSO4 as an osmotic agent due to a greater solute diffusion coefficient of NaCl.

News on alginate recovery by forward osmosis: Reverse solute diffusion is useful

Chemosphere ◽  
2021 ◽  
pp. 131483
Author(s):  
Da-Qi Cao ◽  
Xiu-Zhen Sun ◽  
Wen-Yu Zhang ◽  
Yu-Ting Ji ◽  
Xiao-Xuan Yang ◽  
...  
Keyword(s):  
Forward Osmosis ◽  
Solute Diffusion
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