scholarly journals Advanced multi-nozzle electrospun functionalized titanium dioxide/polyvinylidene fluoride-co-hexafluoropropylene (TiO2/PVDF-HFP) composite membranes for direct contact membrane distillation

2017 ◽  
Vol 524 ◽  
pp. 712-720 ◽  
Author(s):  
Eui-Jong Lee ◽  
Alicia Kyoungjin An ◽  
Pejman Hadi ◽  
Sangho Lee ◽  
Yun Chul Woo ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Direct Contact ◽  
Polyvinylidene Fluoride ◽  
Composite Membranes ◽  
Membrane Distillation ◽  
Direct Contact Membrane Distillation

Porous hydrophobic-hydrophilic composite membranes for direct contact membrane distillation

2019 ◽  
Vol 591 ◽  
pp. 117225 ◽  
Author(s):  
Aishwarya A. Puranik ◽  
Lydia N. Rodrigues ◽  
John Chau ◽  
Lin Li ◽  
Kamalesh K. Sirkar
Keyword(s):  
Direct Contact ◽  
Composite Membranes ◽  
Membrane Distillation ◽  
Direct Contact Membrane Distillation

Characteristic and Performance of Polyvinylidene Fluoride Membranes Blended with Lithium Chloride in Direct Contact Membrane Distillation

2014 ◽  
Vol 69 (9) ◽  
Author(s):  
S. O. Lai ◽  
K. C. Chong ◽  
K. M. Lee ◽  
W. J. Lau ◽  
B. S. Ooi
Keyword(s):  
Lithium Chloride ◽  
Direct Contact ◽  
Polyvinylidene Fluoride ◽  
Membrane Separation ◽  
Polymeric Materials ◽  
Membrane Distillation ◽  
Inversion Method ◽  
Permeate Flux ◽  
Separation Processes ◽  
Direct Contact Membrane Distillation

Membrane distillation (MD) is one of the recent rising membrane separation techniques adopted in the desalination and wastewater treatment. Unlike other pressure-driven separation processes such as reverse osmosis and nanofiltration, MD is a thermal-driven process which involves vapor pressure difference across the feed and permeates solutions. As such, MD requires low energy consumption. Hydrophobic polymeric materials such as polyvinylidene fluoride (PVDF) are frequently used in direct contact membrane distillation (DCMD) due to low surface energy and promising thermal resistance. In this study, the DCMD hollow fiber membranes were separately prepared with PVDF and PVDF blended with lithium chloride (LiCl) through dry/wet phase inversion method. Subsequently, the membranes were used in a DCMD process to remove sodium chloride (NaCl) under different feed inlet temperatures to examine the effect of LiCl additives on the neat membrane. The result showed that by adding LiCl into the neat membrane solution, the finger-like structure was change to a sponge-like structure with microvoids. Furthermore, the performance of the LiCl additive membrane in term of permeate flux was found to be 20% higher compared to that of the neat membrane. Other results of the membrane characteristics were also discussed.      

Integration of Photocatalysis with Ultrafiltration or Membrane Distillation for Removal of Azo Dye Direct Green 99 from Water

2009 ◽  
Vol 12 (1) ◽  
Author(s):  
Sylwia Mozia ◽  
Antoni W. Morawski
Keyword(s):  
Titanium Dioxide ◽  
Azo Dye ◽  
Direct Contact ◽  
Membrane Distillation ◽  
Membrane Processes ◽  
Hybrid Processes ◽  
Direct Contact Membrane Distillation

AbstractAn application of hybrid processes photocatalysis - ultrafiltration (UF) and photocatalysis - direct contact membrane distillation (DCMD, MD) for removal of azo-dye Direct Green 99 from water is presented. Titanium dioxide Aeroxide® P25 (Degussa, Germany) was used as a photocatalyst. It was found that both membrane processes were effective in separation of TiO

Performance evaluation of ePTFE and PVDF flat-sheet module direct contact membrane distillation

2010 ◽  
Vol 62 (2) ◽  
pp. 347-352 ◽  
Author(s):  
Ching-Jung Chuang ◽  
Kuo-Lun Tung ◽  
Yang-Hsiang Fan ◽  
Chii-Dong Ho ◽  
James Huang
Keyword(s):  
Direct Contact ◽  
Polyvinylidene Fluoride ◽  
Membrane Distillation ◽  
Membrane Properties ◽  
Energy Integration ◽  
Permeate Flux ◽  
Increase Energy Efficiency ◽  
Module Design ◽  
Direct Contact Membrane Distillation ◽  
Flat Sheet

This paper reports experiments using a flat-sheet module with 0.18 ∼ 0.45 μm ePTFE (expanded polytetrafluoroethylene) and PVDF (polyvinylidene fluoride) membranes to show the effects of membrane properties, salt concentration and fluid hydrodynamics on the permeate flux and salt rejection of DCMD (direct contact membrane distillation). A theoretical prediction of the permeate flux was carried out, and was in close agreement with the experimental results. In addition, the energy integration of the process was also analyzed in order to evaluate module design to increase energy efficiency. According to the simulated results of the energy integration design, a combination of simultaneous cooling of the permeate stream and an additional heat exchanger to lower the temperature of the permeate stream not only enhances the MD flux, but also reduces energy consumption.

scholarly journals Porous Hydrophobic–Hydrophilic Composite Hollow Fiber and Flat Membranes Prepared by Plasma Polymerization for Direct Contact Membrane Distillation

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 120 ◽  
Author(s):  
Ashok K. Sharma ◽  
Adam Juelfs ◽  
Connor Colling ◽  
Saket Sharma ◽  
Stephen P. Conover ◽  
...  
Keyword(s):  
Hollow Fiber ◽  
Direct Contact ◽  
Plasma Polymerization ◽  
Polyvinylidene Fluoride ◽  
Hydrophobic Surface ◽  
Diffusion Path ◽  
High Water ◽  
Membrane Distillation ◽  
Vapor Flux ◽  
Direct Contact Membrane Distillation

High water vapor flux at low brine temperatures without surface fouling is needed in membrane distillation-based desalination. Brine crossflow over surface-modified hydrophobic hollow fiber membranes (HFMs) yielded fouling-free operation with supersaturated solutions of scaling salts and their precipitates. Surface modification involved an ultrathin porous polyfluorosiloxane or polysiloxane coating deposited on the outside of porous polypropylene (PP) HFMs by plasma polymerization. The outside of hydrophilic MicroPES HFMs of polyethersulfone was also coated by an ultrathin coating of porous plasma-polymerized polyfluorosiloxane or polysiloxane rendering the surface hydrophobic. Direct contact membrane distillation-based desalination performances of these HFMs were determined and compared with porous PP-based HFMs. Salt concentrations of 1, 10, and 20 wt% were used. Leak rates were determined at low pressures. Surface and cross-sections of two kinds of coated HFMs were investigated by scanning electron microscopy. The HFMs based on water-wetted MicroPES substrate offered a very thin gas gap in the hydrophobic surface coating yielding a high flux of 26.4–27.6 kg/m2-h with 1 wt% feed brine at 70 °C. The fluxes of HFMs on porous PP substrates having a long vapor diffusion path were significantly lower. Coated HFM performances have been compared with flat hydrophilic membranes of polyvinylidene fluoride having a similar plasma-polymerized hydrophobic polyfluorosiloxane coating.

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