scholarly journals Current Status and Future Trend of Dominant Commercial Reverse Osmosis Membranes

Membranes ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 906
Author(s):  
Masaru Kurihara
Keyword(s):  
Reverse Osmosis ◽  
Hollow Fiber ◽  
Water Solution ◽  
Cellulose Triacetate ◽  
Future Trend ◽  
Global Market ◽  
Water Desalination ◽  
Current Status ◽  
Membrane Process ◽  
Spiral Wound

Since 2000, seawater reverse osmosis method has been a dominant desalination technology against the distillation method in the global market. The large project called “Mega-SWRO” (half mega-ton per day and larger) plant in the Middle East is quite popular making full use of the combination with solar energy. Today, the price of desalinated water is affordable at as low as $0.28/m3 to $0.53/m3. Likewise, dominant commercial reverse osmosis membrane is a cross-linked fully aromatic polyamide composite membrane-spiral wound element including FT-30 (DuPont Water Solution) and UTC-80 (Toray Industries., Inc., Otsu, Shiga, Japan). The said membranes are much superior in terms of performance compared to the cellulose triacetate membranes-hollow fiber for variety of applications including seawater desalinations, brackish water desalination, wastewater reuse, ultra-pure production for semiconductor, home-use water purifier, etc. SWCC of Saudi Arabia has announced that it intends to shift from cellulose triacetate hollow fiber to spiral wound RO membranes at all of its plants. Furthermore, the state-sponsored R&D on membrane and membrane process has been put into practice in major countries, including Japan and Korea, which contributed to the progress of membrane science and membrane process, suitable for spiral-wound polyamide membranes. SWCC has announced their plans for SWRO, mainly focusing on brine mining to obtain precious materials from the brine of SWRO. New and innovative brine-mining technology has been introduced for green desalination.

scholarly journals Determination of log removal values of bacteria by spiral-wound reverse osmosis modules and a hollow fiber ultrafiltration module using Escherichia coli and indigenous heterotrophic bacteria as indicators

2020 ◽  
Vol 18 (6) ◽  
pp. 956-967
Author(s):  
Yumiko Ohkouchi ◽  
Tomonobu Ase
Keyword(s):  
Escherichia Coli ◽  
Reverse Osmosis ◽  
Hollow Fiber ◽  
Heterotrophic Bacteria ◽  
Operation Mode ◽  
Continuous Mode ◽  
E Coli ◽  
Mode Operation ◽  
Wide Range ◽  
Spiral Wound

Abstract The use of reverse osmosis (RO) membranes has been expanding not only to medical applications but also to water supply and reclaimed water applications due to its strong ability to remove a wide range of contaminants. Many researchers reported RO performance as a barrier against waterborne viruses; however, there are limited reports on its ability to remove bacteria from water. This investigation evaluated the removal performances of several spiral-wound RO modules and a hollow fiber ultrafiltration (UF) module in two different ways: dosing tests in batch-wise mode operation and in continuous-mode operation. The dosing tests of Escherichia coli using RO modules confirmed that E. coli could leak from the feed-side into the permeate. The log removal values (LRVs) (4.21- to >7.44-log10) by the RO modules from different production lots were found to vary greatly. In continuous-mode operation of the RO module, the LRVs for indigenous heterotrophic bacteria decreased over the operation period. These results clearly illustrate that bacteria, which originate on the feed-side, can leak into the permeate-side and then begin to proliferate in the permeate. On the other hand, using a UF module, E. coli was not detected in the permeate regardless of the operation mode.

scholarly journals Ultra-strong polymeric hollow fiber membranes for saline dewatering and desalination

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Can Zeng Liang ◽  
Mohammad Askari ◽  
Looh Tchuin Choong ◽  
Tai-Shung Chung
Keyword(s):  
Reverse Osmosis ◽  
Hollow Fiber ◽  
Pure Water ◽  
Water Desalination ◽  
Hydraulic Pressure ◽  
Hollow Fiber Membranes ◽  
Polymeric Thin Film ◽  
Fiber Membranes ◽  
Water Treatments ◽  
Water Permeance

AbstractOsmotically assisted reverse osmosis (OARO) has become an emerging membrane technology to tackle the limitations of a reverse osmosis (RO) process for water desalination. A strong membrane that can withstand a high hydraulic pressure is crucial for the OARO process. Here, we develop ultra-strong polymeric thin film composite (TFC) hollow fiber membranes with exceptionally high hydraulic burst pressures of up to 110 bar, while maintaining high pure water permeance of around 3 litre/(m2 h bar) and a NaCl rejection of about 98%. The ultra-strong TFC hollow fiber membranes are achieved mainly by tuning the concentration of the host polymer in spinning dopes and engineering the fiber dimension and morphology. The optimal TFC membranes display promising water permeance under the OR and OARO operation modes. This work may shed new light on the fabrication of ultra-strong TFC hollow fiber membranes for water treatments and desalination.

scholarly journals Comparison of Pressure-Retarded Osmosis Performance between Pilot-Scale Cellulose Triacetate Hollow-fiber and Polyamide Spiral-Wound Membrane Modules

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 177
Author(s):  
Yuriko Kakihana ◽  
Nora Jullok ◽  
Masafumi Shibuya ◽  
Yuki Ikebe ◽  
Mitsuru Higa
Keyword(s):  
Power Density ◽  
Hollow Fiber ◽  
Cellulose Triacetate ◽  
Pilot Scale ◽  
Maximum Power ◽  
Optimum Operating ◽  
Maximum Power Density ◽  
Pressure Retarded Osmosis ◽  
Membrane Modules ◽  
Spiral Wound

Pressure-retarded osmosis (PRO) has recently received attention because of its ability to generate power via an osmotic pressure gradient between two solutions with different salinities: high- and low-salinity water sources. In this study, PRO performance, using the two pilot-scale PRO membrane modules with different configurations—five-inch cellulose triacetate hollow-fiber membrane module (CTA-HF) and eight-inch polyamide spiral-wound membrane modules (PA-SW)—was evaluated by changing the draw solution (DS) concentration, applied hydrostatic pressure difference, and the flow rates of DS and feed solution (FS), to obtain the optimum operating conditions in PRO configuration. The maximum power density per unit membrane area of PA-SW at 0.6 M NaCl was 1.40 W/m2 and 2.03-fold higher than that of CTA-HF, due to the higher water permeability coefficient of PA-SW. In contrast, the maximum power density per unit volume of CTA-SW at 0.6 M NaCl was 4.67 kW/m3 and 6.87-fold higher than that of PA-SW. The value of CTA-HF increased to 13.61 kW/m3 at 1.2 M NaCl and was 12.0-fold higher than that of PA-SW because of the higher packing density of CTA-HF.

scholarly journals Advances and Applications of Hollow Fiber Nanofiltration Membranes: A Review

Membranes ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 890
Author(s):  
Tim Sewerin ◽  
Maria G. Elshof ◽  
Sonia Matencio ◽  
Marcel Boerrigter ◽  
Jimmy Yu ◽  
...  
Keyword(s):  
Drinking Water ◽  
Hollow Fiber ◽  
Municipal Wastewater ◽  
Industrial Applications ◽  
Global Market ◽  
Special Focus ◽  
Extreme Conditions ◽  
Nanofiltration Membranes ◽  
Separation Layers ◽  
Spiral Wound

Hollow fiber nanofiltration (NF) membranes have gained increased attention in recent years, partly driven by the availability of alternatives to polyamide-based dense separation layers. Moreover, the global market for NF has been growing steadily in recent years and is expected to grow even faster. Compared to the traditional spiral-wound configuration, the hollow fiber geometry provides advantages such as low fouling tendencies and effective hydraulic cleaning possibilities. The alternatives to polyamide layers are typically chemically more stable and thus allow operation and cleaning at more extreme conditions. Therefore, these new NF membranes are of interest for use in a variety of applications. In this review, we provide an overview of the applications and emerging opportunities for these membranes. Next to municipal wastewater and drinking water processes, we have put special focus on industrial applications where hollow fiber NF membranes are employed under more strenuous conditions or used to recover specific resources or solutes.

scholarly journals Cellulose Triacetate (CTA) Hollow-Fiber (HF) Membranes for Sustainable Seawater Desalination: A Review

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 183
Author(s):  
Takahito Nakao ◽  
Yuki Miura ◽  
Kenji Furuichi ◽  
Masahiro Yasukawa
Keyword(s):  
Reverse Osmosis ◽  
Hollow Fiber ◽  
High Performance ◽  
Cellulose Triacetate ◽  
Optimization Strategy ◽  
Semipermeable Membranes ◽  
Additional Energy ◽  
Recent Developments ◽  
Drinking Water Production ◽  
Seawater Reverse Osmosis

Cellulose triacetate (CTA)-based hollow fiber (HF) membrane is one of the commercially successful semipermeable membranes that has had a long progress since the time the excellent semi-permeable feature of cellulose-based polymers was found in 1957. Because of the reliable and excellent performances, especially for drinking water production from seawater, CTA-HFs have been widely used as reverse osmosis (RO) membranes, especially in arid regions. In this review, recent developments and research trends on CTA-HF membranes for seawater reverse osmosis (SWRO) plants were presented. A flux analytical model, an optimization strategy for chlorine injection without losing salt rejection performance, and a module of current high performance CTA RO membranes along with its plant operation data were updated in this paper. Furthermore, a newly developed CTA-HF membrane for brine concentration (BC) application (called BC membrane) was also addressed. Finally, RO/BC hybrid operation was introduced as an effective SWRO desalination technique that enables minimizing the volume of brine disposal from the RO plant by increasing the recovery ratio and the subsequent amount of produced freshwater, without an additional energy input.

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