scholarly journals Electrospun Nylon 6,6/ZIF-8 Nanofiber Membrane for Produced Water Filtration

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2111 ◽  
Author(s):  
Nur Syakinah Abd Halim ◽  
Mohd Dzul Hakim Wirzal ◽  
Muhammad Roil Bilad ◽  
Nik Abdul Hadi Md Nordin ◽  
Zulfan Adi Putra ◽  
...  

This study develops electrospun nylon 6,6 nanofiber membrane (NFM), incorporating zeolitic imidazolate framework-8 (ZIF-8) as the additive for produced water (PW) filtration. Electrospun NFM is suitable to be used as a filter, especially for water treatment, since it has a huge surface area to volume ratio, high porosity, and great permeability compared to the conventional membranes. These properties also enhance its competitiveness to be used as reverse osmosis pre-treatment, as the final stage of PW treatment water reuse purpose. However, the fouling issue and low mechanical strength of NFM reduces hydraulic performance over time. Therefore, this study employs ZIF-8 as an additive to improve nylon 6,6 NFM properties to reduce fouling and increase membrane tensile strength. Results show that the optimum loading of ZIF-8 was at 0.2%. This loading gives the highest oil rejection (89%), highest steady-state pure water permeability (1967 L/(m2·h·bar)), 2× higher than untreated nylon 6,6 NFM with tensile strength 5× greater (3743 MPa), and a steady-state permeability of 1667 L/(m2·h·bar) for filtration of real produced water.

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 252 ◽  
Author(s):  
Normi Izati Mat Nawi ◽  
Nur Syakinah Abd Halim ◽  
Leong Chew Lee ◽  
Mohd Dzul Hakim Wirzal ◽  
Muhammad Roil Bilad ◽  
...  

The competitiveness of algae as biofuel feedstock leads to the growth of membrane filtration as one of promising technologies for algae harvesting. Nanofiber membrane (NFM) was found to be efficient for microalgae harvesting via membrane filtration, but it is highly limited by its weak mechanical strength. The main objective of this study is to enhance the applicability of nylon 6,6 NFM for microalgae filtration by optimizing the operational parameters and applying solvent vapor treatment to improve its mechanical strength. The relaxation period and filtration cycle could be optimized to improve the hydraulic performance. For a cycle of 5 min., relaxation period of ≤2 min shows the highest steady-state permeability of 365 ± 14.14 L m−2 h−1 bar−1, while for 10 min cycle, 3 min. of relaxation period was found optimum that yields permeability of 402 ± 34.47 L m−2 h−1 bar−1. The treated nylon 6,6 NFM was also used to study the effect of aeration rate. It is confirmed that the aeration rate enhances the steady-state performance for both intermittent and continuous mode of aeration. Remarkably, intermittent aeration shows 7% better permeability than the full aeration for all tested condition, which is beneficial for reducing the total energy consumption.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2117 ◽  
Author(s):  
Nur Syakinah Abd Halim ◽  
Mohd Dzul Hakim Wirzal ◽  
Muhammad Roil Bilad ◽  
Nik Abdul Hadi Md Nordin ◽  
Zulfan Adi Putra ◽  
...  

Electrospun nanofiber membrane (NFM) has a high potential to be applied as a filter for produced water treatment due to its highly porous structure and great permeability. However, it faces fouling issues and has low mechanical properties, which reduces the performance and lifespan of the membrane. NFM has a low integrity and the fine mat easily detaches from the sheet. In this study, nylon 6,6 was selected as the polymer since it offers great hydrophilicity. In order to increase mechanical strength and separation performance of NFM, solvent vapor treatment was implemented where the vapor induces the fusion of fibers. The fabricated nylon 6,6 NFMs were treated with different exposure times of formic acid vapor. Results show that solvent vapor treatment helps to induce the fusion of overlapping fibers. The optimum exposure time for solvent vapor is 5 h to offer full retention of dispersed oil (100% of oil rejection), has 62% higher in tensile strength (1950 MPa) compared to untreated nylon 6,6 NFM (738 MPa), and has the final permeability closest to the untreated nylon 6,6 NFM (733 L/m2.h.bar). It also took more time to get fouled (220 min) compared to untreated NFM (160 min).


Author(s):  
Muhammad Amir Nasrin Mohd Asri ◽  
Nur Syakinah Abd Halim ◽  
Mohd Dzul Hakim Wirzal ◽  
Abdull Rahim Mohd Yusoff ◽  
Muhammad Roil Bilad

As the forefront in fiber materials development, electrospun nanofiber membrane (NFM) is potentially reliable for wastewater treatment due to its excellent properties for instance; large surface area, high porosity, tuneable pore size, and has great flux as compared to other conventional membranes. However, fouling issue will lead to degradation of membrane performance. Fouling issue can be alleviated by applying membrane surface modification. In this study, thermal annealing is applied onto nylon 6,6 nanofiber membrane with three different temperatures (60°C, 80°C and 120°C). Results show that annealing causes membrane shrinkage and reduction of membrane fiber diameter where the fiber reduced from 138.5 nm to 108.5 nm when annealed at 120°C. The optimum annealing temperature for the membrane was found to be at 60˚C as the membrane shows the highest flux at 1200 L/m2.h at 75 minutes filtration time and took longer time to get fouled (>75 minutes) compared with un-annealed membrane (55 minutes). Nylon 6,6 nanofiber membrane is also proven to give more than 90% of COD and turbidity rejection.


2020 ◽  
Vol 15 (3) ◽  
pp. 44-49
Author(s):  
Ibiyemi A. Idowu ◽  
Olutosin O. Ilori

The study examined the effect of fillers on the mechanical properties of the recycled low density polyethylene composites under weathered condition with a view of managing the generation and disposal of plastic wastes. Discarded pure water sachets and fillers (glass and talc) were sourced and recycled. Recycled low density polyethylene (RLDPE) and preparation of RLDPE/glass, RLDPE/talc and RLDPE/glass/talc composites were carried out using a furnace at compositions of 0 – 40% in steps of 10% by weight. The mixtures were poured into hand-laid mould. The samples produced were exposed to sunlight for eight (8) weeks and their mechanical properties were studied. The results of mechanical tests revealed that tensile strength decreased with increasing filler loading while impact strength and hardness property increased marginally and considerably with increasing filler loading for all the composites respectively. The study concluded that glass and talc were able to reinforce recycled low density polyethylene under weathered condition. Keywords: Recycled Low Density Polyethylene (RLDPE); Fillers; Glass, Talc; Weathering condition; Sunlight; and Mechanical properties; Tensile strength, Impact and hardness


2021 ◽  
Author(s):  
Max Olsen ◽  
Ragni Hatlebakk ◽  
Chris Holcroft ◽  
Roar Egil Flatebø ◽  
Asif Hoq ◽  
...  

Abstract This paper reports the development and testing, of a Phosphate controlled dissolution glass composition used to strengthen the matrix of chalk whilst retaining the permeability of the rock, facilitating improved hydrocarbon recovery in unstable wells. Multiple versions of the glass solutions and different types of colloidal silica were extensively tested in the laboratory to determine injectability and reactivity with calcium carbonate rocks. The goal of the testing was to determine the best performing solution for use in a field trial in the Norwegian North Sea. The laboratory testing included filtration and core flood tests to determine the injectability of the solutions and post treatment permeability, and Brazilian strength tests to determine the tensile strength of the treated chalk cores. The filterability was tested through filter screen sizes ranging from 5 to 0.6 µm. Core flood testing was performed on 10 cm long chalk cores with 1.5 mD permeability. The glass solutions showed the best results in the filtration and core flood testing, achieving significantly greater invasion depth than any of the colloidal silica samples. The phosphate glass treated chalk cores maintained 70 to 100% of the original permeability while delivering a 3 to 5 fold tensile strength increase. The lab tests demonstrated the potential of a glass based treatment to strengthen chalk formations without impeding permeability.Based on the promising results from the lab tests, it was decided to trial the selected glass solution in a mature vertical proppant fractured well. The test confirmed that the glass solution could be pumped into the well, but the test failed pre-maturely after two months of varied production, and the trial will not be covered in this paper.However, due to the high value in being able to stabilize chalk in the field, the Operator is evaluating a new trial in a horizontal well, and learnings from the first trial will be used to inform further lab tests in the next phase. The glass solution used in this trial is being further developed to be used in other formation types, such as sand and non-calcium containing reservoirs.


2006 ◽  
Vol 54 (11-12) ◽  
pp. 207-214 ◽  
Author(s):  
B. Rezania ◽  
J.A. Oleszkiewicz ◽  
N. Cicek

An anaerobic submerged membrane bioreactor was coupled with a novel hydrogen delivery system for hydrogenotrophic denitrification of municipal final effluent containing nitrate. The biological treatment unit and hydrogen delivery unit were proven successful in removing nitrate and delivering hydrogen, respectively. Complete hydrogen transfer resulted in reducing nitrate below detectable levels at a loading of 0.14 kg N m−3 d−1. The produced water met all drinking water guidelines except for color and organic carbon. However, the organic carbon was removed by 72% mostly by membrane rejection. To reduce the organic carbon and color of the effluent, post treatment of the produced water is required.


2021 ◽  
Vol 877 (1) ◽  
pp. 012012
Author(s):  
Zahraa N. Mahbouba ◽  
Abdulkhalik K. Mahmood ◽  
Musa H. Alshammari

Abstract Oil and gas sectors generate large amounts of oily wastewater, which is called produced water. In which, it contains high concentrations of hazardous organic and inorganic pollutants. This paper attempts to evaluate the performance and quality of using a polyethersulfone ultrafiltration membrane (UFM) to treat the produced water of Al-Ahdab oil field (Wassit, Iraq). 8 rectangular flat sheets of polyethersulfone ultrafiltration membrane were used. The area of each is 60 cm2 and pore size about 15 nm used in the experimental work. Prepared UFM is characterized by determining the surface morphology by scanning electron microscopy (SEM). The result showed that the UFM indicated high removal efficiency in all parameters and especially oil and grease and total suspended solid but in general it still less than the requirement of water reuse. The results showed that, a combination of a conventional treatment method and UFM technology have higher efficiency than using UFM only.


Author(s):  
N. Chin ◽  
S. O. Lai ◽  
K. C. Chong ◽  
S. S. Lee ◽  
C. H. Koo ◽  
...  

The study was concerned with the treatment of tank dewatering produced water using hybrid microfiltration (MF) and ultrafiltration (UF) processes. The pre-treatment MF membrane was fabricated with polyethersulfone (PES), n-methyl-2-pyrrolidone (NMP) and polyvinylpyrrolidone (PVP). The UF membranes meanwhile contained additional component, i.e., titanium dioxide (TiO2) nanoparticles in the range of zero to 1.0 wt.%. The membrane performances were analysed with respect to permeate flux, oil removal and flux recovery ratio. An increase in TiO2 nanoparticles enhanced the pore formation, porosity and pure water permeability due to improved hydrophilicity. The permeate flux of UF membranes increased with the increase of TiO2 nanoparticles and pressure. The oil removal rate by MF process was only 52.35%, whereas the oil rejection efficiency was between 82.34% and 95.71% for UF process. It should be highlighted that the overall oil removal rate could achieve as high as 97.96%. Based on the results, the PES membrane incorporated with 1.0 wt.% TiO2 was proved to be the most promising membrane at a transmembrane pressure of 3 bar. Although 1.0 M NaOH solution could be used as cleaning agent to recover membrane water flux, it is not capable of achieving good results as only 52.18% recovery rate was obtained.


Ceramics ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 161-179 ◽  
Author(s):  
Frances Su ◽  
Joyce Mok ◽  
Joanna McKittrick

Freeze casting is a technique used to manufacture porous ceramics with aligned microstructures. In conventional freeze casting, these microstructures are aligned along a single direction of freezing. However, a caveat to these ceramics has been their ensuing lack of strength and toughness due to their high porosity, especially in the direction orthogonal to the direction of alignment. In this work, a novel freezing casting method referred to as “radial-concentric freeze casting” is presented, which takes its inspiration from the radially and concentrically aligned structure of the defensive spines of the porcupine fish. The method builds off the radial freeze casting method, in which the microstructure is aligned radially, and imposes a concentric alignment. Axial compression and Brazilian tests were performed to obtain axial compressive strengths, axial compressive moduli, and splitting tensile strengths of freeze cast samples with and without epoxy infiltration. Notably, radial-concentric freeze cast samples had the greatest improvements in axial compressive modulus and splitting tensile strength with infiltration, when compared against the changes in mechanical properties of conventional and radial freeze cast ceramics with infiltration. These results provide further evidence for the importance of structure in multiphase materials and the possibility of enhancing mechanical properties through the controlled alignment of microstructures.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 305 ◽  
Author(s):  
Bishweshwar Pant ◽  
Mira Park ◽  
Soo-Jin Park

Electrospinning has emerged as one of the potential techniques for producing nanofibers. The use of electrospun nanofibers in drug delivery has increased rapidly over recent years due to their valuable properties, which include a large surface area, high porosity, small pore size, superior mechanical properties, and ease of surface modification. A drug loaded nanofiber membrane can be prepared via electrospinning using a model drug and polymer solution; however, the release of the drug from the nanofiber membrane in a safe and controlled way is challenging as a result of the initial burst release. Employing a core-sheath design provides a promising solution for controlling the initial burst release. Numerous studies have reported on the preparation of core-sheath nanofibers by coaxial electrospinning for drug delivery applications. This paper summarizes the physical phenomena, the effects of various parameters in coaxial electrospinning, and the usefulness of core-sheath nanofibers in drug delivery. Furthermore, this report also highlights the future challenges involved in utilizing core-sheath nanofibers for drug delivery applications.


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