scholarly journals Industrial water reclamation using polymeric membranes – case studies involving a car manufacturer and a beverage producer

2013 ◽  
Vol 3 (4) ◽  
pp. 357-372 ◽  
Author(s):  
Bernard A. Agana ◽  
Darrell Reeve ◽  
John D. Orbell
Keyword(s):  
Membrane Surface ◽  
Oxygen Demand ◽  
Low Pressure ◽  
Polymeric Membranes ◽  
Wastewater Reclamation ◽  
Cathodic Electrodeposition ◽  
Flux Decline ◽  
Wastewater Stream ◽  
Ro Membrane ◽  
Uf Membranes

This study presents the evaluation of different polymeric membranes for the reclamation of wastewater generated by two manufacturers. Specifically, ultrafiltration (UF) membranes were evaluated for wastewater pretreatment use while nanofiltration (NF) and reverse osmosis (RO) membranes were evaluated for wastewater reclamation use. Results show that both the UF membranes used were not suitable for pretreatment of the oily wastewater stream due to the presence of suspended cathodic electrodeposition (CED) paint particles. The CED paint particles rapidly deposit on the membrane surface resulting in severe fouling and very low permeate fluxes. With respect to the metals and beverage wastewater streams, the polyvinylidine-difluoride (PVDF) UF membrane was shown to be more suitable for pretreatment than the polyacrylonitrile UF membrane. The PVDF-UF membrane had relatively lower flux decline rates, higher turbidity and higher total organic carbon reduction rates. Meanwhile, the low-pressure RO membrane proved to be suitable for wastewater reclamation of the oily and beverage wastewater streams – showing low flux decline rates, high conductivity and high chemical oxygen demand reduction rates. In terms of reclaiming the metals wastewater stream, the NF membrane proved more suitable than the low-pressure RO membrane. The NF membrane had relatively higher permeate fluxes and metals rejection rates compared to the RO membrane.

Intermittent operation of low pressure UF membranes for sewage reuse at household level

2013 ◽  
Vol 68 (4) ◽  
pp. 799-806 ◽  
Author(s):  
Vasileios I. Diamantis ◽  
Konstantinos Anagnostopoulos ◽  
Paraschos Melidis ◽  
Spyridon Ntougias ◽  
Alexander Aivasidis
Keyword(s):  
Oxygen Demand ◽  
Low Pressure ◽  
Transmembrane Pressure ◽  
Secondary Effluent ◽  
Nitrogen And Phosphorus ◽  
Household Level ◽  
Relaxation Period ◽  
Layer Cake ◽  
Cake Layer ◽  
Uf Membranes

A household-scale wastewater treatment system was operated with domestic sewage. The system could recover gardening/irrigation water from raw sewage or secondary effluent by low pressure ultrafiltration (UF). The UF membranes (surface area = 3.5 m2, pore size = 0.04 μm) were operated at constant transmembrane pressure (0.13 bar). The proposed technology was examined for approximately 2 months without membrane cleaning. Membrane operation was performed periodically (one or two times per week), simulating water usage for gardening irrigation. During raw sewage filtration (chemical oxygen demand (COD) total = 242 ± 71 mg L–1, COD soluble = 105 ± 51 mg L−1, suspended solids = 188 ± 58 mg L−1), low permeate COD was achieved (52 ± 25 mg L−1), whereas nitrogen and phosphorus were recovered in the permeate. The water recovered during 1 h of operation displayed a gradual decrease from 42 to 22 L m−2h−1 during the 50-d time period. For the secondary effluent filtration, the UF module achieved consistently a recovery rate of 39.6 ± 8.0 L m−2h−1, with an average permeate COD of 37 mg L−1. In this case, the fouling layer (cake layer) was completely reversible after the relaxation period, rendering the process suitable for unattended household applications.

scholarly journals Modification of a polyamide reverse osmosis membrane by heat treatment for enhanced fouling resistance

2013 ◽  
Vol 13 (6) ◽  
pp. 1553-1559 ◽  
Author(s):  
Takahiro Fujioka ◽  
Long D. Nghiem
Keyword(s):  
Heat Treatment ◽  
Reverse Osmosis ◽  
Membrane Surface ◽  
Pure Water ◽  
Surface Characteristics ◽  
Skin Layer ◽  
Secondary Effluent ◽  
Fouling Resistance ◽  
Flux Decline ◽  
Ro Membrane

The use of heat treatment to improve solute rejection and fouling resistance of a polyamide reverse osmosis (RO) membrane was investigated in this study. Heat treatment was carried out by immersing the membrane samples in Milli-Q water at 70 °C for a specific duration. Heat treatment (24 h) reduced the pure water permeability from 4.1 to 2.8 L/m2hbar but improved conductivity rejection from 95.5 to 97.0%. As a result, a correlation was observed between changes in the two parameters. Marginal changes in the membrane surface characteristics (i.e. zeta potential, hydrophobicity, chemistry and roughness) were observed as a result of heat treatment. Heat treatment significantly improved the fouling resistance property of the RO membrane. When the secondary effluent was filtrated at an elevated permeated flux, the virgin RO membrane exhibited 30% flux decline while the heat-treated membrane showed only 12% flux decline. This is possibly because heat treatment resulted in a denser cross-linked active skin layer, thus reducing the blockage caused by small organic foulants.

SEM/FESEM imaging of lamellar structures in melt extruded polyethylene films

1992 ◽  
Vol 50 (2) ◽  
pp. 1142-1143
Author(s):  
R.T. Chen ◽  
M.G. Jamieson ◽  
R. Callahan
Keyword(s):  
Imaging Techniques ◽  
Membrane Surface ◽  
High Stress ◽  
Extrusion Direction ◽  
Polymeric Membranes ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Crystalline Polymers ◽  
Lamellar Structures ◽  
Resolution Imaging

“Row lamellar” structures have previously been observed when highly crystalline polymers are melt-extruded and recrystallized under high stress. With annealing to perfect the stacked lamellar superstructure and subsequent stretching in the machine (extrusion) direction, slit-like micropores form between the stacked lamellae. This process has been adopted to produce polymeric membranes on a commercial scale with controlled microporous structures. In order to produce the desired pore morphology, row lamellar structures must be established in the membrane precursors, i.e., as-extruded and annealed polymer films or hollow fibers. Due to the lack of pronounced surface topography, the lamellar structures have typically been investigated by replica-TEM, an indirect and time consuming procedure. Recently, with the availability of high resolution imaging techniques such as scanning tunneling microscopy (STM) and field emission scanning electron microscopy (FESEM), the microporous structures on the membrane surface as well as lamellar structures in the precursors can be directly examined.The materials investigated are Celgard® polyethylene (PE) flat sheet membranes and their film precursors, both as-extruded and annealed, made at different extrusion rates (E.R.).

Fouling Is the Beginning: Upcycling Biopolymer-Fouled Substrates for Fabricating High-Permeance Thin-Film Composite Polyamide Membranes

2020 ◽  
Author(s):  
Ruobin Dai ◽  
Hongyi Han ◽  
Tianlin Wang ◽  
Jiayi Li ◽  
Chuyang Y. Tang ◽  
...  
Keyword(s):  
Thin Film ◽  
High Pressure ◽  
End Of Life ◽  
Water Purification ◽  
Low Pressure ◽  
Polymeric Membranes ◽  
Membrane Recycling ◽  
Film Composite ◽  
Thin Film Composite ◽  
First Time

Commercial polymeric membranes are generally recognized to have low sustainability as membranes need to be replaced and abandoned after reaching the end of their life. At present, only techniques for downcycling end-of-life high-pressure membranes are available. For the first time, this study paves the way for upcycling fouled/end-of-life low-pressure membranes to fabricate new high-pressure membranes for water purification, forming a closed eco-loop of membrane recycling with significantly improved sustainability.

scholarly journals Nanometals-Containing Polymeric Membranes for Purification Processes

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 513
Author(s):  
Anna Rabajczyk ◽  
Maria Zielecka ◽  
Krzysztof Cygańczuk ◽  
Łukasz Pastuszka ◽  
Leszek Jurecki
Keyword(s):  
Synergistic Effects ◽  
Membrane Surface ◽  
Antibacterial Properties ◽  
Polymeric Membranes ◽  
Treatment Processes ◽  
Wide Range ◽  
Different Types ◽  
Type Size ◽  
Titanium Zinc ◽  
Membrane Surface Charge

A recent trend in the field of membrane research is the incorporation of nanoparticles into polymeric membranes, which could produce synergistic effects when using different types of materials. This paper discusses the effect of the introduction of different nanometals such as silver, iron, silica, aluminum, titanium, zinc, and copper and their oxides on the permeability, selectivity, hydrophilicity, conductivity, mechanical strength, thermal stability, and antiviral and antibacterial properties of polymeric membranes. The effects of nanoparticle physicochemical properties, type, size, and concentration on a membrane’s intrinsic properties such as pore morphology, porosity, pore size, hydrophilicity/hydrophobicity, membrane surface charge, and roughness are discussed, and the performance of nanocomposite membranes in terms of flux permeation, contaminant rejection, and antifouling capability are reviewed. The wide range of nanocomposite membrane applications including desalination and removal of various contaminants in water-treatment processes are discussed.

scholarly journals Influence of bulk concentration on the organisation of molecules at a membrane surface and flux decline during reverse osmosis of an anionic surfactant

2016 ◽  
Vol 499 ◽  
pp. 257-268 ◽  
Author(s):  
Zhaohuan Mai ◽  
Vincent Butin ◽  
Mohammed Rakib ◽  
Haochen Zhu ◽  
Murielle Rabiller-Baudry ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Anionic Surfactant ◽  
Membrane Surface ◽  
Bulk Concentration ◽  
Flux Decline

Membrane filtration of wastewater effluents for reuse: effluent organic matter rejection and fouling

2001 ◽  
Vol 43 (10) ◽  
pp. 225-232 ◽  
Author(s):  
C. Jarusutthirak ◽  
G. Amy
Keyword(s):  
Organic Matter ◽  
Membrane Filtration ◽  
Treated Wastewater ◽  
High Concentration ◽  
Effluent Organic Matter ◽  
Dead End ◽  
Flux Decline ◽  
Uf Membranes ◽  
Stirred Cell ◽  
Filtration Unit

The reuse of treated wastewater to augment natural drinking water supplies is receiving serious consideration. Treatment of secondary and tertiary effluent by membrane filtration was investigated by assessing nanofiltration (NF) membrane and ultrafiltration (UF) membranes in bench-scale experiments. It was found that secondary and tertiary effluent contained high concentration of effluent organic matter (EfOM), contributing EfOM-related fouling. Flux decline and EfOM rejection tests were evaluated, using a dead-end stirred cell filtration unit. Surface charge and molecular weight cut-off (MWCO) of membranes were significant factors in membrane performance including permeability and EfOM-rejection.

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.

Topology Optimization of Spacers for Maximizing Permeate Flux on Membrane Surface in Reverse Osmosis Channel

2011 ◽  
Author(s):  
Seungjae Oh ◽  
Semyung Wang ◽  
Minkyu Park ◽  
Joonha Kim
Keyword(s):  
Topology Optimization ◽  
Pressure Drop ◽  
Reverse Osmosis ◽  
Membrane Surface ◽  
Design Development ◽  
Permeate Flux ◽  
Membrane Channel ◽  
Initial Attempt ◽  
Membrane Surfaces ◽  
Ro Membrane

The objective of this study is to design spacers using fluid topology optimization in 2D crossflow Reverse Osmosis (RO) membrane channel to improve the performance of RO processes. This study is an initial attempt to apply topology optimization to designing spacers in RO membrane channel. The performance was evaluated by the quantity of permeate flux penetrating both upper and lower membrane surfaces. A coupled Navier-Stokes and Convection-Diffusion model was employed to calculate the permeate flux. To get reliable solutions, stabilization methods were employed with standard finite element method. The nine reference models which consist of the combination of circle, rectangular, triangle shape and zigzag, cavity, submerge configuration of spacers were simulated. Such models were compared with new model designed by topology optimization. The permeate flux at both membrane surfaces was determined as an objective function. In addition, permissible pressure drop along the channel and spacer volume were used as constraints. As a result of topology optimization as the permissible pressure drop changes in channel, characteristics of spacer design development was founded. Spacer design based on topology optimization was reconstructed to a simple one considering manufactuability and characteristics of development spacer design. When a simplified design was compared with previous 9 models, new design has a better performance in terms of permeate flux and wall concentration at membrane surface.

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