Modeling of the fouling of inside-out hollow fiber UF membranes

2016 ◽  
Vol 17 (1) ◽  
pp. 300-310 ◽  
Author(s):  
Xudong Wang ◽  
Danxi Huang ◽  
Lei Wang ◽  
Xiaorong Meng ◽  
Yongtao Lv ◽  
...  
Keyword(s):  
Hollow Fiber ◽  
Membrane Fouling ◽  
Operating Conditions ◽  
Constant Current ◽  
Operating Pressure ◽  
Water Recovery ◽  
Permeate Flux ◽  
Uf Membranes ◽  
Blocking Coefficient ◽  
Inside Out

Membrane processes often experience a decline in the permeate flux or an increase in the operating pressure from membrane fouling. A mathematical model that describes the fouling of inside-out hollow fiber ultrafiltration (UF) membranes was derived from hydrodynamic equations coupled with the theory of depth filtration. The correlation predictions obtained in this study are simpler, as the effect of membrane characteristics, water recovery, and membrane washing processes on UF membrane fouling were expressed using a single parameter: the membrane blocking coefficient. Membrane filtration tests were conducted using diluted paper industry wastewater in a constant-pressure and constant-current operational mode. The effects of different operating conditions, such as water recovery and cleaning methods, and membrane characteristics, on the membrane blocking coefficient were evaluated. The predictive capability of the proposed model was excellent, according to a comparison of the experimental results and model simulations.

Numerical Simulation of Hollow Fiber Ultrafiltration Membrane

2009 ◽  
Author(s):  
Nina Zhou ◽  
A. G. Agwu Nnanna
Keyword(s):  
Numerical Model ◽  
Hollow Fiber ◽  
Membrane Fouling ◽  
Hollow Fiber Membrane ◽  
Membrane Surface ◽  
Operating Conditions ◽  
Permeate Flux ◽  
High Productivity ◽  
Design And Optimization ◽  
Membrane Performance

Low pressure driven ultrafiltraion (UF) processes has been applied in various industries due to its economical and easy operated benefits. Hollow fiber membrane is one of the most used membrane configuration in industry, membrane fouling is the major challenge for widely usage. Most of the investigation of UF was carried out by experiments to determine the effect of different operating conditions on permeate flux. However, experiments provide limited insight information on the membrane performance. In addition, the prediction of permeate flux under different operating conditions is necessary for experimental design and optimization. The purpose of the present study is to develop a numerical model to simulate the UF process and investigate the UF mechanism. A numerical model was developed using commercial CFD package (FLUENT). The effects of various operating conditions on permeate flux were determined by experiments and simulations, the comparison of the experimental and CFD results shows good agreements. Controlling membrane fouling will maintain a high productivity. The simulations were carried out to investigate the efficiency of removing accumulated particles on membrane surface by installing spacer filaments in membrane channels. The results suggested that the zigzag type spacer has d/h = 0.5 and l/h = 5 is more economical and efficient in reducing fouling.

scholarly journals Fouling Removal of UF Membrane with Coated TiO2Nanoparticles under UV Irradiation for Effluent Recovery during TFT-LCD Manufacturing

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
S. H. You ◽  
C. T. Wu
Keyword(s):  
Uv Irradiation ◽  
Membrane Fouling ◽  
Liquid Crystal Display ◽  
Membrane Surface ◽  
Thin Film Transistor ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Secondary Effluent ◽  
Operating Pressure ◽  
Permeate Flux

An ultrafiltration (UF) membrane process was employed to treat the secondary effluent discharged from a manufacturing of thin film transistor-liquid crystal display (TFT-LCD) in this study. A bench-scale system was performed to evaluate the fouling removal of a UF membrane with coated titanium dioxide (TiO2) nanoparticles under UV irradiation. The operating pressure and feed temperature were controlled at 300 KN/m2and 25°C, respectively. It was found that the optimum operating conditions were attained with TiO2concentrations of 10 wt% for both 5 KD and 10 KD MWCO. Continuous UV irradiation of 5 KD MWCO improved the permeate flux rate from 45.0% to 59.5% after 4 hours of operation. SEM-EDS analysis also showed that the photocatalytic effect had reduced the average thickness of cake fouling on the membrane from 6.40 μm to 2.70 μm for 5 KD MWCO and from 6.70 μm to 3.1 μm for 10 KD MWCO. In addition, the membrane contact angle was reduced from 54° to 44°. The photocatalytic properties of TiO2apparently increased the hydrophilicity of the membrane surface, thereby reducing membrane fouling.

scholarly journals Direct Membrane Filtration for Wastewater Treatment Using an Intermittent Rotating Hollow Fiber Module

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1836
Author(s):  
Ignacio Ruigómez ◽  
Enrique González ◽  
Luis Rodríguez-Gómez ◽  
Luisa Vera
Keyword(s):  
Hollow Fiber ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Colloidal Particles ◽  
Rotation Speed ◽  
Operating Conditions ◽  
Permeate Flux ◽  
Cake Filtration ◽  
Fouling Control ◽  
Continuous Rotation

Direct membrane filtration of municipal wastewater has attracted a considerable interest in recent years. Preventing severe membrane fouling is a crucial issue in the process development. This paper aims to assess the effectiveness of a rotating hollow fiber module in enhancing fouling control. The effect of rotation speed, intermittence and permeate flux was studied in short-term tests at lab-scale. A combined filtration model considering residual fouling, intermediate pore blocking and cake filtration was used to analyze the effect of the shear induced by rotation. Results showed a significant flux improvement by increasing rotation shear stress and showed a nearly linear correlation between the threshold flux (ranged between 12 and 32 L·h−1·m−2) and the rotation speed. A proper rotation intermittence (10/15 on/off) was found, which may maintain a fouling control comparable to that achieved for continuous rotation. For a given energy demand, the optimal operating conditions involve high speeds (≥180 rev·min−1) with low to moderate intermittences. Analyzing the relative contribution of the different feedwater fractions on membrane fouling, colloidal particles and macromolecules were found to be the main contributors.

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.

scholarly journals Zwitterion-Modified Ultrafiltration Membranes for Permian Basin Produced Water Pretreatment

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1710 ◽  
Author(s):  
Mirjalal Babayev ◽  
Hongbo Du ◽  
Venkata S. V. Botlaguduru ◽  
Raghava R. Kommalapati
Keyword(s):  
Membrane Fouling ◽  
Oil And Gas ◽  
Produced Water ◽  
Forward Osmosis ◽  
Dip Coating ◽  
Permeate Flux ◽  
Permian Basin ◽  
Water Pretreatment ◽  
Uf Membranes ◽  
Surface Modified

Unconventional oil and gas extraction generates large quantities of produced water (PW). Due to strict environmental regulations, it is important to recover and reuse PW. In this study, commercial polyethersulfone (PES) ultrafiltration (UF) membranes were surface-modified with zwitterionic polymer 3-(3,4-Dihydroxyphenyl)-l-alanine (l-DOPA) solution to alleviate membrane fouling during the ultrafiltration of shale oil PW of the Permian Basin. UF membranes were coated in l-DOPA solution by using a dip coating technique. Membrane characterization tests confirmed successful l-DOPA coating on UF membranes. While performing the experiments, permeate flux behaviors of the uncoated and coated membranes and antifouling resistance of the zwitterionic coating were evaluated. Among the coated UF membranes with varying coating times from one day to three days, the three-day coated UF membrane showed a good flux performance and the highest fouling resistance. The flux reduced by 38.4% for the uncoated membrane, while the reduction was 16% for the three-day coated membrane after the 5 h ultrafiltration of PW. Both improvements of the flux performance and recovery ratio are attributed to a negatively-charged surface developed on the membranes after the zwitterionic coating. The UF pretreatment also improved the flux behavior of the later forward osmosis (FO) process for PW treatment.

Effect of the operating parameters on the separation of metal chelates using low pressure reverse osmosis membrane (LPROM)

2000 ◽  
Vol 41 (10-11) ◽  
pp. 135-142 ◽  
Author(s):  
Z. Ujang ◽  
G.K. Anderson
Keyword(s):  
Factorial Design ◽  
Metal Removal ◽  
Feed Solution ◽  
Metal Chelates ◽  
Operating Conditions ◽  
Operating Parameters ◽  
Operating Pressure ◽  
Permeate Flux ◽  
Experimental Conditions ◽  
Central Composite

This paper describes an investigation on the effect of operating parameters on the separation of metal chelates using LPROM. The objective of this study was to optimise the process of metal chelates removal by a LPROM using statistical factorial design. Factorial experiment by statistical design was applied, in which a central composite factorial design (half replicate) was used, then followed up by a star design to give a central composite factorial design. A bench-scale spiral wound configuration of sulphonated polysulphone LPROM was used at various operating conditions, i.e. operating conditions, solute concentrations, EDTA, pH and temperature. It has been shown experimentally that the effect of pressure is non-linear with respect to percentage of metal removal at different concentrations of metal ions in the feed solution. Observation of the response surface implies that the operating pressure was not the significant parameter in determining the percentage of zinc removal in the LPROM. The operating pressure, temperature and concentration of EDTA in the feed solution were the most significant parameters for permeate flux variation. It can also be concluded that for a given set of feed and experimental conditions, permeate flux increased linearly with operating pressure and temperature. The other parameters, i.e. the concentration of zinc in the feed solution and pH, were not statistically significant.

scholarly journals Effects of tannic acid on membrane fouling and membrane cleaning in forward osmosis

2017 ◽  
Vol 76 (11) ◽  
pp. 3160-3170 ◽  
Author(s):  
Wanzhu Zhang ◽  
Lin Wang ◽  
Bingzhi Dong
Keyword(s):  
Tannic Acid ◽  
Calcium Ions ◽  
Membrane Fouling ◽  
Driving Forces ◽  
Forward Osmosis ◽  
Operating Conditions ◽  
Permeate Flux ◽  
Membrane Cleaning ◽  
Draw Solution ◽  
Cleaning Methods

Abstract The fouling behavior during forward osmosis (FO) was investigated. Tannic acid was used as a model organic foulant for natural organic matter analysis since the main characteristics are similar, and calcium ions were added at different concentrations to explore the anti-pollution capability of FO membranes. The initial permeate flux and calcium ions strength were varied in different operating conditions to describe membrane fouling with membrane cleaning methods. The observed flux decline in FO changed dramatically with the type of foulant and the type of draw solution used to provide the osmotic driving force. Calcium ions aggravated membrane fouling and decreased transmembrane flux. Membrane cleaning methods included physical and physicochemical approaches, and there was no obvious difference among the typical cleaning methods (i.e., membrane flushing with different types of cleaning fluids at various crossflow velocities and backwashing with varying osmotic driving forces) with respect to flux recovery. Ultrasonic cleaning damaged the membrane structure and decreased permeate flux, and reverse diffusion of salt from the draw solution to the feed side accelerated after cleaning.

Filtration of crude canola oil miscella utilizing PVDF membrane: the effects of pretreatments and operating conditions

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Razieh Niazmand ◽  
Reza Farhoosh ◽  
Seyed Mohammad Ali Razavi
Keyword(s):  
Canola Oil ◽  
Polyvinylidene Fluoride ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Permeate Flux ◽  
Pvdf Membrane ◽  
Flat Membrane ◽  
Temperature And Pressure ◽  
Increasing Temperature ◽  
Membrane Cell

Abstract This study was conducted on adding chemical agents (aqueous solutions of CaCl2, EDTA and SDS) to crude canola oil miscella before ultrafiltration through polyvinylidene fluoride (PVDF) membrane with MWCO 50 kDa in a magnetically stirred flat membrane cell. Operating conditions including pressures 2-5 bar and temperatures 25-55 °C were employed. Permeate flux of pretreated oil samples exhibited sharp risings with increasing temperature and pressure. Except for the oils pretreated with SDS, the rejection of free fatty acids (FFAs) decreased in all oil samples. Increasing the operating pressure to 4 bar decreased the rejection of FFAs. Pretreatment of the oils with SDS and EDTA resulted in higher amounts of phosphorous rejection, while increasing temperature decreased it. Reduction of color values (L, a, and b) of the oil samples was not considerable through the PVDF membrane.

Analysis of nanoporous membrane fouling relying on experimental observation and theoretical model for landfill leachate treatment

2015 ◽  
Vol 73 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Mohsen Jahanshahi ◽  
Majid Peyravi ◽  
Nader Shafaei ◽  
Hatef Mirani
Keyword(s):  
Landfill Leachate ◽  
Membrane Fouling ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Operating Pressure ◽  
Feed Concentration ◽  
Leachate Treatment ◽  
Nanoporous Membrane ◽  
Flux Decline ◽  
Pore Blockage

This paper is focused on the fouling behaviour of the ultrafiltration membrane for landfill leachate treatment. Natural organic matter fouling is considered a critical factor controlling the membrane performance. In this regard, the polyethersulphone nanoporous membrane was fabricated by phase inversion. In order to investigate the effects of operating conditions on fouling, landfilled leachate treatment was done at different transmembrane pressure and feed concentration. At high concentration of landfill leachate, the effect of operating pressure can be negligible. The maximum amount of RFR was 0.961 for raw landfill leachate. Flux decline data were also obtained for the filtration of landfill leachate. The rates of flux decline drastically dropped to about 46–48% of the initial values in the first 30 minutes of the experiment at all the examined pressures. The data were also analyzed using a model in order to provide explanations for simultaneous pore blockage and cake formation. The model showed very good agreement with the data for all transmembrane pressures and feed concentrations. The initial fouling due to pore blockage is related to the feed concentration at constant pressure, so by diluting the feed concentration, the effect of pore blocking was increased.

Sign in / Sign up

Export Citation Format

Share Document