Performance of Surface Modification of Polyvinylidene Fluoride Hollow Fiber Membrane in Membrane Distillation

Membrane distillation (MD) is one of the novel separation methods used in water and wastewater treatment processes. MD is a thermal driven process which has the potential to be integrated with renewable energy source and can be operated at very low pressure. Polyvinylidene fluoride (PVDF) is a hydrophobic polymeric material which is commonly used to prepare MD membrane. In this study, surface modifying macromolecule (SMM) was added as additive into PVDF dope solution and then the hollow fiber membrane was prepared using phase inversion process. The membrane was characterized with respect to morphology and permeates flux at different temperatures. The results revealed that the PVDF membrane blended with SMM exhibited higher permeate flux than PVDF neat membrane did, mainly due to the better pore size distribution and thinner skin layer. This finding indicated the role of SMM in modifying the properties of PVDF membrane for MD process.

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

Water Science & Technology ◽

10.2166/wst.2021.201 ◽

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.

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Lake Water Treatment Using Polyurethane-Polyvinylidene Fluoride Hollow Fiber Blend Membrane and Polyvinylidene Fluoride Hollow Fiber Membrane in a Coagulation-Microfiltration Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.755 ◽

2012 ◽

Vol 518-523 ◽

pp. 755-759

Author(s):

Liang Wang ◽

Bin Zhao ◽

Shu Ling Ma ◽

Hong Wei Zhang ◽

Qin Yang

Keyword(s):

Hollow Fiber ◽

Lake Water ◽

Polyvinylidene Fluoride ◽

Hollow Fiber Membrane ◽

Pollutant Removal ◽

Transmembrane Pressure ◽

Permeate Flux ◽

Fiber Membrane ◽

Blend Membrane ◽

Ring Structures

Polyurethane-polyvinylidene fluoride (PU-PVDF) hollow fiber blend membrane prepared by melting, spinning and drawing processes was used to treat lake water in a submerged coagulation-microfiltration (SCMF) process. This novel membrane is characterized by its elastic pore size increase with the pressure increase; therefore, the backwashing step could effectively remove the depositions stuck in membrane pores. Compared to the system using polyvinylidene fluoride (PVDF) hollow fiber membrane, the membrane anti-fouling ability was stronger in the system using PU-PVDF blend membrane, and the transmembrane pressure increased more slowly at a fixed permeate flux. Organic matters were removed comparably for both membranes during the first 3 h treatment, but those with benzene ring structures were susceptibly restricted by PU-PVDF blend membrane as the filtration went on. The turbidity removal was stable in the PU-PVDF system with an average of 97%, and was slightly higher than that in the PVDF system. The outstanding anti-fouling ability and excellent pollutant removal performance make the PU-PVDF hollow fiber blend membrane a better candidate for the SCMF process.

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Seawater Desalination by Modified Membrane Distillation: Effect of Hydrophilic Surface Modifying Macromolecules Addition into PVDF Hollow Fiber Membrane

Membranes ◽

10.3390/membranes11120924 ◽

2021 ◽

Vol 11 (12) ◽

pp. 924

Author(s):

Mochammad Purwanto ◽

Nindita Cahya Kusuma ◽

Ma’rup Ali Sudrajat ◽

Juhana Jaafar ◽

Atikah Mohd Nasir ◽

...

Keyword(s):

Hollow Fiber ◽

Polyvinylidene Fluoride ◽

Hollow Fiber Membrane ◽

Membrane Distillation ◽

Hydrophilic Surface ◽

Hollow Fiber Membranes ◽

Permeate Flux ◽

Seawater Desalination ◽

Salt Rejection ◽

Fiber Membranes

Hollow fiber membranes of polyvinylidene fluoride (PVDF) were prepared by incorporating varying concentrations of hydrophilic surface-modifying macromolecules (LSMM) and a constant amount of polyethylene glycol (PEG) additives. The membranes were fabricated by the dry-wet spinning technique. The prepared hollow fiber membranes were dip-coated by hydrophobic surface-modifying macromolecules (BSMM) as the final step fabrication. The additives combination is aimed to produce hollow fiber membranes with high flux permeation and high salt rejection in the matter of seawater desalination application. This study prepares hollow fiber membranes from the formulation of 18 wt. % of PVDF mixed with 5 wt. % of PEG and 3, 4, and 5 wt. % of LSMM. The membranes are then dip-coated with 1 wt. % of BSMM. The effect of LSMM loading on hydrophobicity, morphology, average pore size, surface porosity, and membrane performance is investigated. Coating modification on LSMM membranes showed an increase in contact angle up to 57% of pure, unmodified PVDF/PEG membranes, which made the fabricated membranes at least passable when hydrophobicity was considered as one main characteristic. Furthermore, The PVDF/PEG/4LSMM-BSMM membrane exhibits 161 °C of melting point as characterized by the DSC. This value indicates an improvement of thermal behavior shows so as the fabricated membranes are desirable for membrane distillation operation conditions range. Based on the results, it can be concluded that PVDF/PEG membranes with the use of LSMM and BSMM combination could enhance the permeate flux up to 81.32 kg·m−2·h−1 at the maximum, with stable salt rejection around 99.9%, and these are found to be potential for seawater desalination application.

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Dye wastewater treatment by direct contact membrane distillation using polyvinylidene fluoride hollow fiber membranes

Journal of Polymer Engineering ◽

10.1515/polyeng-2014-0214 ◽

2015 ◽

Vol 35 (5) ◽

pp. 471-479 ◽

Cited By ~ 19

Author(s):

Nadzirah M. Mokhtar ◽

Woei J. Lau ◽

Ahmad F. Ismail

Keyword(s):

Hollow Fiber ◽

Membrane Fouling ◽

Direct Contact ◽

Polyvinylidene Fluoride ◽

Gas Permeability ◽

Hollow Fiber Membrane ◽

Membrane Distillation ◽

Reactive Black 5 ◽

Pvdf Membrane ◽

Direct Contact Membrane Distillation

Abstract The potential of 18 wt.% polyvinylidene fluoride (PVDF) hollow fiber membrane blended with ethylene glycol (EG) for the treatment of dye solution using direct contact membrane distillation (DCMD) system was investigated. The PVDF membrane was prepared using the dry-jet wet spinning method and was characterized in terms of membrane morphology, porosity, wetting pressure, gas permeability and degree of hydrophobicity. The membrane was tested using dye solution containing 0.5 g l-1 reactive black 5 (RB5). The experimental period was prolonged to 6 h in order to analyze the fouling tendency and membrane durability during the DCMD process. The results showed that the modified PVDF membrane was able to produce consistent flux (i.e., 9.82±0.52 kg m-2 h-1) throughout the DCMD experiment while maintaining excellent dye rejection (i.e., 99.86±0.04%). With respect to membrane fouling, it was found that the lumen side of the membrane was significantly stained with color (compared to outer membrane surface) due to the physical-chemical interaction between reactive dye and membrane structure. Although membrane fouling was experienced in this study, its impact on MD performance in terms of flux and rejection was negligible, mainly because MD is not a pressure-driven process.

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Permeate Flux and Rejection Behavior in Submerged Direct Contact Membrane Distillation Process Treating a Low-Strength Synthetic Wastewater

Applied Sciences ◽

10.3390/app10020677 ◽

2020 ◽

Vol 10 (2) ◽

pp. 677 ◽

Cited By ~ 1

Author(s):

Woobin Bae ◽

Jeonghwan Kim

Keyword(s):

Hollow Fiber ◽

Direct Contact ◽

Hollow Fiber Membrane ◽

Membrane Distillation ◽

Synthetic Wastewater ◽

Permeate Flux ◽

Fiber Membrane ◽

Direct Contact Membrane Distillation ◽

Mixing Intensity ◽

Low Strength

The effects of operational conditions such as permeate recirculation velocity, mixing intensity, and trans-membrane temperature on the performances of hydrophobic polyethylene (PE) hollow-fiber membrane were investigated by operating the submerged direct contact membrane distillation (SDCMD) process treating a synthetic low-strength wastewater. Permeate flux of the membrane increased with increasing a permeate recirculation velocity through the fiber lumen. However, the effectiveness was less pronounced as the velocity was higher than 0.5 m/s. Increasing rotational speed to 600 rpm, which can lead to mixing intensity from a bulk wastewater toward hollow-fiber membrane, enhanced permeate flux. Feed temperature played a more significant role in enhancing permeate flux rather than a permeate temperature under constant trans-membrane temperature. The SDCMD process treating a synthetic low-strength wastewater achieved an excellent rejection efficiency which is higher than 97.8% for both chemical oxygen demand (CODCr) and total phosphorus (T-P) due to the hydrophobic property of membrane material which can allow water vapor through membrane. However, the rejection efficiency of the ammonia nitrogen (NH3-N) was relatively low at about 87.5% because ammonia gas could be volatized easily through membrane pores in SDCMD operation. In a long-term operation of the SDCMD process, the permeate flux decreased significantly due to progressive formation of inorganic scaling on membrane.

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Removal of 1,1,1-trichloroethane from water using a polyvinylidene fluoride hollow fiber membrane module: Vacuum membrane distillation operation

Separation and Purification Technology ◽

10.1016/j.seppur.2006.05.013 ◽

2006 ◽

Vol 52 (2) ◽

pp. 301-309 ◽

Cited By ~ 58

Author(s):

Bing Wu ◽

Xiaoyao Tan ◽

K. Li ◽

W.K. Teo

Keyword(s):

Hollow Fiber ◽

Polyvinylidene Fluoride ◽

Hollow Fiber Membrane ◽

Membrane Distillation ◽

Membrane Module ◽

Fiber Membrane ◽

Vacuum Membrane Distillation

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Development of mass and heat transfer coupled model of hollow fiber membrane for salt recovery from brine via osmotic membrane distillation

Environmental Sciences Europe ◽

10.1186/s12302-021-00520-z ◽

2021 ◽

Vol 33 (1) ◽

Author(s):

Sher Ahmad ◽

Gabriela Vollet Marson ◽

Waheed Ur Rehman ◽

Mohammad Younas ◽

Sarah Farrukh ◽

...

Keyword(s):

Mass Transfer ◽

Transfer Coefficient ◽

Mass Transfer Coefficient ◽

Heat And Mass Transfer ◽

Hollow Fiber ◽

Hollow Fiber Membrane ◽

Membrane Distillation ◽

Fiber Membrane ◽

Salt Recovery ◽

Osmotic Solution

Abstract Background In this research work, a coupled heat and mass transfer model was developed for salt recovery from concentrated brine water through an osmotic membrane distillation (OMD) process in a hollow fiber membrane contactor (HFMC).The model was built based on the resistance-in-series concept for water transport across the hydrophobic membrane. The model was adopted to incorporate the effects of polarization layers such as temperature and concentration polarization, as well as viscosity changes during concentration. Results The modeling equations were numerically simulated in MATLAB® and were successfully validated with experimental data from literature with a deviation within the range of 1–5%. The model was then applied to study the effects of key process parameters like feed concentrations, osmotic solution concentration, feed, and osmotic solution flow rates and feed temperature on the overall heat and mass transfer coefficient as well as on water transport flux to improve the process efficiency. The mass balance modeling was applied to calculate the membrane area based on the simulated mass transfer coefficient. Finally, a scale-up for the MD process for salt recovery on an industrial scale was proposed. Conclusions This study highlights the effect of key parameters for salt recovery from wastewater using the membrane distillation process. Further, the applicability of the OMD process for salt recovery on large scale was investigated. Sensitivity analysis was performed to identify the key parameters. From the results of this study, it is concluded that the OMD process can be promising in salt recovery from wastewater.

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