scholarly journals Filtration analysis and fouling mechanisms of PVDF membrane for POME treatment

2020 ◽  
Vol 10 (3) ◽  
pp. 187-199
Author(s):  
Mohd Azwan Ahmad ◽  
Bidattul Syirat Zainal ◽  
Nashrah Hani Jamadon ◽  
Thomas Choong Shean Yaw ◽  
Luqman Chuah Abdullah
Keyword(s):  
Membrane Fouling ◽  
Membrane Surface ◽  
Water Flux ◽  
Permeate Flux ◽  
Cake Filtration ◽  
Pvdf Membrane ◽  
Fouling Mechanism ◽  
Promising Treatment ◽  
Palm Oil Mill ◽  
Treatment Design

Abstract Palm oil mill effluent (POME) is a hazardous wastewater which contains high organic constituents and salt concentrations. The ultrafiltration (UF) process is a promising treatment design used for secondary treatment such as POME. However, membrane fouling is the major problem which limits the performance of the UF. This paper describes a detailed investigation of polyvinylidiene fluoride (PVDF) membrane for the treatment of POME. The fouling behavior was analyzed by water flux, fouling mechanism, scanning electron microscopy (SEM), particle size distribution (PSD) and Energy Dispersive X-ray (EDX). It was found that a significant reduction in the permeate flux was caused by the build up of a fouling layer. Study on the fouling mechanism shows that cake filtration dominated the fouling activities on the membrane surface, compared to standard blocking, intermediate blocking, and complete blocking. This result is supported by membrane autopsy through SEM, PSD and EDX.

scholarly journals Effect of the Zwitterion, p(MAO-DMPA), on the Internal Structure, Fouling Characteristics, and Dye Rejection Mechanism of PVDF Membranes

Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 323
Author(s):  
Nelisa Ncumisa Gaxela ◽  
Philiswa Nosizo Nomngongo ◽  
Richard Motlhaletsi Moutloali
Keyword(s):  
Internal Structure ◽  
Membrane Fouling ◽  
Vinylidene Fluoride ◽  
Membrane Surface ◽  
Pure Water ◽  
Water Flux ◽  
Proton Nuclear Magnetic Resonance ◽  
Pvdf Membrane ◽  
Membrane Performance ◽  
Dye Rejection

The zwitterion poly-(maleic anhydride-alt-1-octadecene-3-(dimethylamino)-1-propylamine) (p(MAO-DMPA)) synthesized using a ring-opening reaction was used as a poly(vinylidene fluoride) (PVDF) membrane modifier/additive during phase inversion process. The zwitterion was characterized using proton nuclear magnetic resonance (1HNMR) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Atomic force microscopy (AFM), field emission scanning electron microscope (SEM), FTIR, and contact angle measurements were taken for the membranes. The effect of the zwitterionization content on membrane performance indicators such as pure water flux, membrane fouling, and dye rejection was investigated. The morphology of the membranes showed that the increase in the zwitterion amount led to a general decrease in pore size with a concomitant increase in the number of membrane surface pores. The surface roughness was not particularly affected by the amount of the additive; however, the internal structure was greatly influenced, leading to varying rejection mechanisms for the larger dye molecule. On the other hand, the wettability of the membranes initially decreased with increasing content to a certain point and then increased as the membrane homogeneity changed at higher zwitterion percentages. Flux and fouling properties were enhanced through the addition of zwitterion compared to the pristine PVDF membrane. The high (>90%) rejection of anionic dye, Congo red, indicated that these membranes behaved as ultrafiltration (UF). In comparison, the cationic dye, rhodamine 6G, was only rejected to <70%, with rejection being predominantly electrostatic-based. This work shows that zwitterion addition imparted good membrane performance to PVDF membranes up to an optimum content whereby membrane homogeneity was compromised, leading to poor performance at its higher loading.

scholarly journals DETERMINATION OF FOULING MECHANISM IN ULTRAFILTRATION OF ELECTROPLATING WASTEWATER

2018 ◽  
Vol 80 (3-2) ◽  
Author(s):  
Danu Ariono ◽  
Anita Kusuma Wardani ◽  
Putu Teta Prihartini Aryanti ◽  
Ahmad Nurul Hakim ◽  
I Gede Wenten
Keyword(s):  
Flow Velocity ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Cross Flow ◽  
Permeate Flux ◽  
High Concentration ◽  
Filtration Time ◽  
Electroplating Wastewater ◽  
Fouling Mechanism ◽  
Cross Flow Velocity

Wastewater from electroplating industries is usually contaminated with high concentration of hazardous materials, such as nickel, copper, and chromium. Therefore, the electroplating wastewater is one of the environmental problems that require a novel solution to reduce risks for human and environment. Ultrafiltration is a promising technology to overcome this problem due to its ability to reject all suspended solids. However, membrane fouling still becomes a major obstacle in ultrafiltration processes. Fouling reduces the permeate flux and increases membrane operational costs due to membrane cleaning. In this work, fouling mechanism that occurred in polyacrylonitrile based ultrafiltration for electroplating wastewater treatment was investigated. The effects of trans-membrane pressure (TMP) and cross flow velocity on fouling mechanism were also studied. The results showed that in the first 20 minutes, intermediate blocking was occurred on the membrane surface, while cake formation was happened for the rest of filtration time. These results were applied for all TMP and cross flow velocity.

scholarly journals Recovery of Methyl Green from Aqueous Solution using NF Membrane

2017 ◽  
Vol 12 (1) ◽  
Author(s):  
P. Sharma ◽  
M. M. Bora ◽  
S. Hazarika ◽  
S. Borthakur ◽  
C. Tamuli ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Transport Model ◽  
Membrane Surface ◽  
Water Flux ◽  
Applied Pressure ◽  
Membrane Resistance ◽  
Methyl Green ◽  
Permeate Flux ◽  
Pore Flow ◽  
Polyamide Membrane

Recovery of a cationic synthetic dye, methyl green by nanofiltration (NF 270–400) membrane from commercial source (Filmtec, USA) was used for this study. The effect of membrane characteristics, applied pressure gradient ( ΔP ) and aqueous phase concentration of dye on the rejection, membrane fouling and water flux was studied over a range of pressure and concentration of 2 to 5 bar and 0.01 mmole L–1 to 0.05 mmole L–1 respectively. The solution flux increases with pressure in the pressure range studied indicate the effect of concentration polarization is not significant in this range. The cation shield effects of the dye on the negatively charged polyamide membrane perhaps result in decrease of permeate flux with concentration. The permeation phenomenon has been analyzed on the basis of pore flow transport model and the data analysis revealed that adsorption of dye on the membrane surface and intrinsic membrane resistance control the permeate flux.

scholarly journals ZnO Microfiltration Membranes for Desalination by a Vacuum Flow-Through Evaporation Method

Membranes ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 156 ◽  
Author(s):  
Shailesh Dangwal ◽  
Ruochen Liu ◽  
Lyndon D. Bastatas ◽  
Elena Echeverria ◽  
Chengqian Huang ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Membrane Surface ◽  
Water Flux ◽  
Atomic Layer ◽  
Rejection Rate ◽  
Contact Angles ◽  
Transfer Resistance ◽  
Membrane Pore ◽  
Evaporation Method ◽  
Flow Through

ZnO was deposited on macroporous α-alumina membranes via atomic layer deposition (ALD) to improve water flux by increasing their hydrophilicity and reducing mass transfer resistance through membrane pore channels. The deposition of ZnO was systemically performed for 4–128 cycles of ALD at 170 °C. Analysis of membrane surface by contact angles (CA) measurements revealed that the hydrophilicity of the ZnO ALD membrane was enhanced with increasing the number of ALD cycles. It was observed that a vacuum-assisted ‘flow-through’ evaporation method had significantly higher efficacy in comparison to conventional desalination methods. By using the vacuum-assisted ‘flow-through’ technique, the water flux of the ZnO ALD membrane (~170 L m−2 h−1) was obtained, which is higher than uncoated pristine membranes (92 L m−2 h−1). It was also found that ZnO ALD membranes substantially improved water flux while keeping excellent salt rejection rate (>99.9%). Ultrasonic membrane cleaning had considerable effect on reducing the membrane fouling.

Electroflocculation as potential pretreatment in colloid ultrafiltration

2006 ◽  
Vol 6 (1) ◽  
pp. 69-78 ◽  
Author(s):  
T. Harif ◽  
M. Hai ◽  
A. Adin
Keyword(s):  
Membrane Fouling ◽  
Colloidal Suspension ◽  
Membrane Surface ◽  
Constant Current ◽  
Permeate Flux ◽  
Batch Mode ◽  
Membrane Behavior ◽  
Flux Decline ◽  
Stainless Steel Cathode ◽  
Marginal Improvement

Electroflocculation (EF) is a coagulation/flocculation process in which active coagulant species are generated in situ by electrolytic oxidation of an appropriate anode material. The effect of colloidal suspension pretreatment by EF on membrane fouling was measured by flux decline at constant pressure. An EF cell was operated in batch mode and comprised two flat sheet electrodes, an aluminium anode and stainless steel cathode, which were immersed in the treated suspension, and connected to an external DC power supply. The cell was run at constant current between 0.06–0.2A. The results show that pre-EF enhances the permeate flux at pH 5 and 6.5, but only marginal improvement is observed at pH 8. At all pH values cake formation on the membrane surface was observed. The differences in membrane behavior can be explained by conventional coagulation theory and transitions between aluminium mononuclear species which affect particle characteristics and consequently cake properties. At pH 6.5, where sweep floc mechanism dominates due to increased precipitation of aluminium hydroxide, increased flux rates were observed. It is evident that EF can serve as an efficient pretreatment to ultrafiltration of colloid particles.

A Wall Film Model for Membrane Fouling

2018 ◽  
Author(s):  
Sina Jahangiri Mamouri ◽  
Volodymyr V. Tarabara ◽  
André Bénard
Keyword(s):  
Multiphase Flow ◽  
Membrane Fouling ◽  
Oil And Gas ◽  
Membrane Separation ◽  
Film Formation ◽  
Membrane Surface ◽  
Permeate Flux ◽  
Water Separation ◽  
Wall Film ◽  
Oil Water

Deoiling of produced or impaired waters associated with oil and gas production represents a significant challenge for many companies. Centrifugation, air flotation, and hydrocyclone separation are the current methods of oil removal from produced water [1], however the efficiency of these methods decreases dramatically for droplets smaller than approximately 15–20 μm. More effective separation of oil-water mixtures into water and oil phases has the potential to both decrease the environmental footprint of the oil and gas industry and improve human well-being in regions such as the Gulf of Mexico. New membrane separation processes and design of systems with advanced flow management offer tremendous potential for improving oil-water separation efficacy. However, fouling is a major challenge in membrane separation [2]. In this study, the behavior of oil droplets and their interaction with crossflow filtration (CFF) membranes (including membrane fouling) is studied using computational fluid dynamics (CFD) simulations. A model for film formation on a membrane surface is proposed for the first time to simulate film formation on membrane surfaces. The bulk multiphase flow is modeled using an Eulerian-Eulerian multiphase flow model. A wall film is developed from mass and momentum balances [3] and implemented to model droplet deposition and membrane surface blockage. The model is used to predict film formation and subsequent membrane fouling, and allow to estimate the actual permeate flux. The results are validated using available experimental data.

scholarly journals The Modification of PVDF Membrane via Crosslinking with Chitosan and Glutaraldehyde as the Crosslinking Agent

2018 ◽  
Vol 18 (1) ◽  
pp. 1
Author(s):  
Romaya Sitha Silitonga ◽  
Nurul Widiastuti ◽  
Juhana Jaafar ◽  
Ahmad Fauzi Ismail ◽  
Muhammad Nidzhom Zainol Abidin ◽  
...  
Keyword(s):  
Contact Angle ◽  
Vinylidene Fluoride ◽  
Membrane Surface ◽  
Pure Water ◽  
Water Flux ◽  
Crosslinking Agent ◽  
Hydrophobic Properties ◽  
Pvdf Membrane ◽  
Pure Water Flux ◽  
Modified Membrane

Poly(vinylidene fluoride) (PVDF) has outstanding properties such as high thermal stability, resistance to acid solvents and good mechanical strength. Due to its properties, PVDF is widely used as a membrane matrix. However, PVDF membrane is hydrophobic properties, so as for specific applications, the surface of membrane needs to be modified to become hydrophilic. This research aims to modify PVDF membrane surface with chitosan and glutaraldehyde as a crosslinker agent. The FTIR spectra showed that the modified membrane has a peak at 1655 cm-1, indicating the imine group (–N=C)- that was formed due to the crosslink between amine group from chitosan and aldehyde group from glutaraldehyde. Results showed that the contact angle of the modified membrane decreases to 77.22° indicated that the membrane hydrophilic properties (< 90°) were enhanced. Prior to the modification, the contact angle of the PVDF membrane was 90.24°, which shows hydrophobic properties (> 90°). The results of porosity, Ɛ (%) for unmodified PVDF membrane was 55.39%, while the modified PVDF membrane has a porosity of 81.99%. Similarly, by modifying the PVDF membrane, pure water flux increased from 0.9867 L/m2h to 1.1253 L/m2h. The enhancement of porosity and pure water flux for the modified PVDF membrane was due to the improved surface hydrophilicity of PVDF membrane.

scholarly journals Characterization of the Initial Fouling Layer on the Membrane Surface in a Membrane Bioreactor: Effects of Permeation Drag

Membranes ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 121
Author(s):  
Shengli Wang ◽  
Xin Lu ◽  
Lanhe Zhang ◽  
Jingbo Guo ◽  
Haifeng Zhang
Keyword(s):  
Zeta Potential ◽  
Electron Donor ◽  
Energy Barrier ◽  
Polyvinylidene Fluoride ◽  
Membrane Bioreactor ◽  
Membrane Surface ◽  
Permeate Flux ◽  
Pvdf Membrane ◽  
Operating Modes

In this study, the properties of the initial fouling layer on the membrane surface of a bioreactor were investigated under different operating modes (with or without permeate flux) to improve the understanding of the effect of permeation drag on the formation of the initial fouling layer. It was found that protein was the major component in the two types of initial fouling layers, and that the permeation drag enhanced the tryptophan protein-like substances. The attraction of the initial foulants to the polyvinylidene fluoride (PVDF) membrane was ascribed to the high zeta potential and electron donor component (γ−) of the membrane. Thermodynamic analyses showed that the permeation drag-induced fouling layer possessed high hydrophobicity and low γ−. Due to permeation drag, a portion of the foulants overcame an energy barrier before they contacted the membrane surface, which itself possessed a higher fouling propensity. A declining trend of the cohesive strength among the foulants was found with the increasing development of both fouling layers.

Influence of humic acid on the long-term performance of direct contact membrane distillation

2018 ◽  
Vol 30 (1) ◽  
pp. 109-120 ◽  
Author(s):  
Dong-Wan Cho ◽  
Gihoon Kwon ◽  
Jeongmin Han ◽  
Hocheol Song
Keyword(s):  
Humic Acid ◽  
Membrane Fouling ◽  
Coalbed Methane ◽  
Direct Contact ◽  
Membrane Surface ◽  
Membrane Distillation ◽  
Permeate Flux ◽  
Direct Contact Membrane Distillation ◽  
High Level

In this study, the influence of humic acid on the treatment of coalbed methane water by direct contact membrane distillation was examined with bench-scale test unit. During short-term distillation (1000 min), high level of humic acid above 50 ppm resulted in significant decrease in permeate flux, while low level of humic acid (∼2 ppm) had little influence on the flux. For the long-term distillation (5000 min), the flux decline began at 3400 min in the presence of 5 ppm humic acid and 5 mM Ca2+, and decreased to ∼40% of initial flux at 5000 min. The spectroscopic analysis of the membrane used revealed that the surface was covered by hydrophilic layers mainly composed of calcite. The membrane fouling effect of humic acid became more significant in the presence of Ca2+ due to more facile calcite formation on the membrane surface. It was demonstrated that humic acid enhanced CaCO3 deposition on the membrane surfaces, thereby expediting the scaling phenomenon.

Ultrafiltration Behavior of Organic Mixtures Simulating Sweetwater Solutions: Influence of Membrane Surface and Feed Chemistry

2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Indok Nurul Hasyimah Mohd Amin ◽  
Abdul Wahab Mohammad
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Glycerol Water ◽  
Pvdf Membrane ◽  
Organic Mixtures ◽  
Rich Solution ◽  
Organic Solute ◽  
Pes Membrane

One of the major drawbacks for the successful of ultrafiltration (UF) during pretreatment of glycerin-rich solution is membrane fouling due to the deposition of triglycerides (TG) and fatty acids (FA). In the present study, attempts were made to examine the filtration behaviour of organic mixtures (oleic acid-triglycerides) compared to single organic solute (triglycerides) contained in synthetic glycerol-water solutions (known as sweetwater). Furthermore, the rejections of individual solutes were studied. The TG-FA mixtures permeated preferentially when compared with single TG which is mainly due to the solubility as well as diffusivity of small fatty acid in the TG-FA mixtures. Furthermore, PVDF membrane provided higher fluxes and experienced less fouling than PES membrane for both cases. In case of PVDF membrane, the rejection of fatty acid was 6.20% while oil rejection in glycerol-water plus TG and TG-FA mixtures was 82.42% and 84.67%, respectively. However, PES membrane underwent higher fatty acid rejection (20.93%) as well as oil rejection in single TG (94.70%) and TG-FA mixtures (91.08%). It is noteworthy that the nature of the membrane and the feed characteristics had a significant effect on the fouling potential and filtration performance.

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