Hydrophobicity versus Pore Size: Polymer Coatings to Improve Membrane Wetting Resistance for Membrane Distillation

2020 ◽  
Vol 2 (3) ◽  
pp. 1256-1267 ◽  
Author(s):  
Allyson L. McGaughey ◽  
Prathamesh Karandikar ◽  
Malancha Gupta ◽  
Amy E. Childress
Keyword(s):  
Pore Size ◽  
Polymer Coatings ◽  
Membrane Distillation ◽  
Membrane Wetting

scholarly journals Large-pore-size membranes tuned by chemically vapor deposited nanocoatings for rapid and controlled desalination

RSC Advances ◽  
2020 ◽  
Vol 10 (66) ◽  
pp. 40562-40568
Author(s):  
Mengfan Zhu ◽  
Yu Mao
Keyword(s):  
Pore Size ◽  
Chemical Vapor ◽  
Membrane Distillation ◽  
Permeate Flux ◽  
Flux Enhancement ◽  
Large Pore ◽  
Chemically Vapor Deposited ◽  
Membrane Wetting ◽  
Large Pore Size ◽  
Significant Flux

Chemical vapor modification simultaneously improved the membrane wetting resistance and permeate flux for membrane distillation. The modification enabled desalination using membranes with pore size > 1 μm and demonstrated significant flux enhancement.

scholarly journals Refinery processed water treatment via the low energy Direct Contact Membrane Distillation (DCMD)

2019 ◽  
Vol 74 ◽  
pp. 3 ◽  
Author(s):  
Khadije El Kadi ◽  
Isam Janajreh ◽  
Raed Hashaikeh ◽  
Rizwan Ahmed
Keyword(s):  
Water Treatment ◽  
Pore Size ◽  
Mass Flux ◽  
Thermal Efficiency ◽  
Membrane Distillation ◽  
Low Energy ◽  
Water Separation ◽  
Oil Water Separation ◽  
Oil Water ◽  
Oil Fouling

The amount of refinery water discharged to the environment from oil industry has increased vigorously in current times. Recent research has been focusing on the use of membrane technology for the refinery processed water treatment. Membrane Distillation (MD) is an emerging technology that has been highly marked by its low-energy requirement and high desalination efficiency. However, conventional MD membranes (i.e. PVDF) are not feasible for oil-water separation processes. That is due to the oleo-philic property of the membrane and thus, causes membrane fouling and halts the production of mass flux. An anti-oil-fouling membrane is essential for a successful oil-water separation by MD. Underwater-oleophobic as well as omniphobic are two different approaches in fabricating such membranes. The former approach is based on the asymmetric surface wettability, whereas the latter is attributed to the surface structure that is characterized by having a very large contact angle for all liquids. However, such composite membranes are characterized by their lower porosity, smaller pore size, but with unique surface slippage, in comparable with the conventional PVDF membranes. As such, in this work, high fidelity numerical simulation of DCMD is performed using non-isothermal Computational Fluid Dynamics (CFD) validated model in order to assess the role of the anti-oil-fouling membrane properties on the performance of the DCMD. Results are presented in terms of temperature polarization coefficient, mass flux, latent heat flux, and thermal efficiency. Results show the compromising effect of membrane porosity to 45% reduces the mass flux and thermal efficiency respectively by 68% and 40%, and reduction of pore size to the half (i.e. 50 nm) can cause a reduction by 50.6% in mass flux and 24.18% in thermal efficiency compared to the baseline (i.e. 100 nm). On the other hand, the omniphobic slippage effect leads to a noticeable gain of 16% in DCMD mass flux with slight gain in thermal efficiency. This can maximize mass flux and thermal efficiency to be as much as 50.3 kg/m2 h and 69%, respectively.

scholarly journals The Water Flux Dynamic in a Hybrid Forward Osmosis-Membrane Distillation for Produced Water Treatment

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 225
Author(s):  
Normi Izati Mat Nawi ◽  
Muhammad Roil Bilad ◽  
Ganeswaran Anath ◽  
Nik Abdul Hadi Nordin ◽  
Jundika Candra Kurnia ◽  
...  
Keyword(s):  
Water Treatment ◽  
Produced Water ◽  
Water Flux ◽  
Forward Osmosis ◽  
Membrane Distillation ◽  
Flux Dynamics ◽  
Flux Dynamic ◽  
Produced Water Treatment ◽  
Dynamic Hybrid ◽  
Membrane Wetting

Standalone membrane distillation (MD) and forward osmosis (FO) have been considered as promising technologies for produced water treatment. However, standalone MD is still vulnerable to membrane-wetting and scaling problems, while the standalone FO is energy-intensive, since it requires the recovery of the draw solution (DS). Thus, the idea of coupling FO and MD is proposed as a promising combination in which the MD facilitate DS recovery for FO—and FO acts as pretreatment to enhance fouling and wetting-resistance of the MD. This study was therefore conducted to investigate the effect of DS temperature on the dynamic of water flux of a hybrid FO–MD. First, the effect of the DS temperature on the standalone FO and MD was evaluated. Later, the flux dynamics of both units were evaluated when the FO and DS recovery (via MD) was run simultaneously. Results show that an increase in the temperature difference (from 20 to 60 °C) resulted in an increase of the FO and MD fluxes from 11.17 ± 3.85 to 30.17 ± 5.51 L m−2 h−1, and from 0.5 ± 0.75 to 16.08 L m−2 h−1, respectively. For the hybrid FO–MD, either MD or FO could act as the limiting process that dictates the equilibrium flux. Both the concentration and the temperature of DS affected the flux dynamic. When the FO flux was higher than MD flux, DS was diluted, and its temperature decreased; both then lowered the FO flux until reaching an equilibrium (equal FO and MD flux). When FO flux was lower than MD flux, the DS was concentrated which increased the FO flux until reaching the equilibrium. The overall results suggest the importance of temperature and concentration of solutes in the DS in affecting the water flux dynamic hybrid process.

scholarly journals Reversing membrane wetting in membrane distillation: comparing dryout to backwashing with pressurized air

2017 ◽  
Vol 3 (5) ◽  
pp. 930-939 ◽  
Author(s):  
David M. Warsinger ◽  
Amelia Servi ◽  
Grace B. Connors ◽  
Musthafa O. Mavukkandy ◽  
Hassan A. Arafat ◽  
...  
Keyword(s):  
Saline Water ◽  
Membrane Distillation ◽  
Feed Water ◽  
Membrane Wetting

Wetting of saline water through membrane distillation pores can be reversed with either drying out the membrane, or more effectively, by backwashing with pressurized air to force out wetting feed water.

Application and modification of polysulfone membranes

2018 ◽  
Vol 34 (5) ◽  
pp. 657-693 ◽  
Author(s):  
Sareh Kheirieh ◽  
Morteza Asghari ◽  
Morteza Afsari
Keyword(s):  
Thermal Stability ◽  
Membrane Fouling ◽  
Chemical Resistance ◽  
Lithium Ion ◽  
Composite Membranes ◽  
Membrane Distillation ◽  
Pollutant Removal ◽  
Water And Wastewater Treatment ◽  
Water And Wastewater ◽  
Membrane Wetting

Abstract Polysulfone (PSf) is a favorite polymer for the production of membrane due to its excellent physicochemical properties, including thermal stability; good chemical resistance to different materials such as different bases, acids, and chlorine; sufficient mechanical strength; and good processability. The present study offers an overview of the recent development in the application and modification of PSf membranes, focusing on some applications such as water and wastewater treatment, membrane distillation, pollutant removal, gas separation, separator for lithium ion battery, and support of composite membranes. In general, there are two major difficulties in the use of membranes made of PSf: membrane fouling and membrane wetting. Therefore, PSf membrane with good anticompaction and antifouling properties is reviewed. Finally, important issues related to the modification of PSf membranes for real applications are discussed. This article provides an intelligent direction for the progress of PSf membranes in the future.

scholarly journals Separation of volatile compounds from fermentation broth by membrane distillation

2011 ◽  
Vol 13 (3) ◽  
pp. 56-60 ◽  
Author(s):  
Marek Gryta ◽  
Marta Barancewicz
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Pore Size ◽  
Volatile Compounds ◽  
Fermentation Broth ◽  
Membrane Distillation ◽  
Volatile Components ◽  
Hydrophobic Properties ◽  
Fermentation Products ◽  
Polypropylene Membrane ◽  
Acetic Acids

Separation of volatile compounds from fermentation broth by membrane distillation The diluted ethanol solutions and fermentation broth (Saccharomyces cerevisiae) were separated by membrane distillation (MD). Hydrophobic macroporous (pore size 0.2 μm) capillary polypropylene membranes, Accurel PP V8/2 HF and Accurel PP S6/2, were used for these studies. The MD process can be successfully applied to remove the volatile components from the fermentation broth. Besides ethanol, propionic and acetic acids were moved from the broth to the distillate. Therefore, the course of the fermentation carried out in a membrane distillation bioreactor considerably accelerate its rate and increase the efficiency by a selective removal of fermentation products. It was found that the broth subjected to the separation did not affect the hydrophobic properties of the polypropylene membrane assembled in the MD modules.

scholarly journals Modification of porous polyetherimide hollow fiber membrane by dip-coating of Zonyl® BA for membrane distillation of dyeing wastewater

2021 ◽  
Author(s):  
S. A. Mousavi ◽  
Z. Arab Aboosadi ◽  
A. Mansourizadeh ◽  
B. Honarvar
Keyword(s):  
Pore Size ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Membrane Surface ◽  
Pure Water ◽  
Dip Coating ◽  
Membrane Distillation ◽  
Permeate Flux ◽  
Fiber Membrane ◽  
Air Gap Membrane Distillation

Abstract Wetting and fouling have significantly affected the application of membrane distillation (MD). In this work, a dip-coating method was used for improving surface hydrophobicity of the polyetherimide (PEI) hollow fiber membrane. An air gap membrane distillation (AGMD) process was applied for treatment of the methylene blue (MB) solution. The porous PEI membrane was fabricated by a dry-wet spinning process and the hydrophobic 2-(Perfluoroalkyl) ethanol (Zonyl® BA) was used as the coating material. From FESEM, the modified PEI-Zonyl membrane showed an open structure with large finger-like cavities. The modified membrane displayed a narrow pore size distribution with mean pore size of 0.028 μm. The outer surface contact angle of the PEI-Zonly membrane increased from 81.3° to 100.4° due to the formation of an ultra-thin coated layer. The pure water flux of the PEI-Zonyl membrane was slightly reduced compared to the pristine PEI membrane. The permeate flux of 6.5 kg/m2 h and MB rejection of 98% was found for the PEI-Zonyl membrane during 76 h of the AGMD operation. Adsorption of MB on the membrane surface was confirmed based on the Langmuir isotherm evaluation, AFM and FESM analysis. The modified PEI-Zonyl membrane can be a favorable alternative for AGMD of dyeing wastewaters.

scholarly journals Membrane distillation crystallization using PVDF membrane incorporated with TiO2 nanoparticles and nanocellulose

2020 ◽  
Vol 20 (5) ◽  
pp. 1629-1642 ◽  
Author(s):  
Hoi-Fang Tan ◽  
Why-Ling Tan ◽  
N. Hamzah ◽  
M. H. K. Ng ◽  
B. S. Ooi ◽  
...  
Keyword(s):  
Pore Size ◽  
Tio2 Nanoparticles ◽  
Polyvinylidene Fluoride ◽  
Phase Inversion ◽  
Membrane Distillation ◽  
Coagulation Bath ◽  
Membrane Thickness ◽  
Permeate Flux ◽  
Sem Images ◽  
Pvdf Membrane

Abstract Polyvinylidene fluoride (PVDF) membrane was improved using TiO2 nanoparticles and nanocellulose for membrane distillation crystallization in this work. Besides the addition of TiO2 nanoparticles and nanocellulose, PVDF membrane was post-modified with octadecyltrichlorosilane after phase inversion using a dual coagulation bath. The addition of hydrophilic TiO2 nanoparticles and nanocellulose reduced membrane hydrophobicity, but the dispersed TiO2 nanoparticles assisted silane modification to improve surface hydrophobicity. Besides reducing the agglomeration of TiO2 nanoparticles, nanocellulose induced the formation of larger pore size and higher porosity as proven in SEM images and gravimetric measurement, respectively. The abundant moieties of nanocellulose accelerated the exchange between solvent and non-solvent during phase inversion for the formation of large pore size and porosity, but membrane thickness increased due to the thickening effects. The modified membrane showed higher water permeate flux in membrane distillation with salt rejection greater than 97%. Severe fouling in membrane distillation crystallization was not observed.

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