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Sample records for osmosis ro water

  1. Efficiently Combining Water Reuse and Desalination through Forward Osmosis-Reverse Osmosis (FO-RO) Hybrids: A Critical Review.

    Science.gov (United States)

    Blandin, Gaetan; Verliefde, Arne R D; Comas, Joaquim; Rodriguez-Roda, Ignasi; Le-Clech, Pierre

    2016-07-01

    Forward osmosis (FO) is a promising membrane technology to combine seawater desalination and water reuse. More specifically, in a FO-reverse osmosis (RO) hybrid process, high quality water recovered from the wastewater stream is used to dilute seawater before RO treatment. As such, lower desalination energy needs and/or water augmentation can be obtained while delivering safe water for direct potable reuse thanks to the double dense membrane barrier protection. Typically, FO-RO hybrid can be a credible alternative to new desalination facilities or to implementation of stand-alone water reuse schemes. However, apart from the societal (public perception of water reuse for potable application) and water management challenges (proximity of wastewater and desalination plants), FO-RO hybrid has to overcome technical limitation such as low FO permeation flux to become economically attractive. Recent developments (i.e., improved FO membranes, use of pressure assisted osmosis, PAO) demonstrated significant improvement in water flux. However, flux improvement is associated with drawbacks, such as increased fouling behaviour, lower rejection of trace organic compounds (TrOCs) in PAO operation, and limitation in FO membrane mechanical resistance, which need to be better considered. To support successful implementation of FO-RO hybrid in the industry, further work is required regarding up-scaling to apprehend full-scale challenges in term of mass transfer limitation, pressure drop, fouling and cleaning strategies on a module scale. In addition, refined economics assessment is expected to integrate fouling and other maintenance costs/savings of the FO/PAO-RO hybrid systems, as well as cost savings from any treatment step avoided in the water recycling.

  2. Pengaruh Kepuasan Dan Kepercayaan Terhadap Keputusan Pembelian Ulang Pada Depot Air Minum Tris Water Reverse Osmosis System (Ro)

    OpenAIRE

    Fitria, Ika

    2011-01-01

    Kind of this survey is asociative survey which watch influence of customer satisfaction and trust to re-purchase decision on Depot Air Minum Tris Water Reverse Osmosis System (RO) and test of hypothesis use Multiple Linear Regression Analysist on α=5%. This survey used SPSS 16.00 version for windows. Research population is consumers of Depot Air Minum Tris Water Reverse Osmosis System (RO). Sample was used in this survey from customers of Depot Air Minum Tris Water Reverse Osmosis System (RO)...

  3. Performances of nano filtration (NF) and reverse osmosis (RO) in textile industry waste water treatment

    International Nuclear Information System (INIS)

    Ellouze, E.; Souissi, S.; Ben Amar, R.; Ben Salah, A.; Jrad, A.

    2009-01-01

    Textile industry process (dyeing, bleaching, printing and finishing) require a high-water consumption generating high amounts of water. Reactive dyeing of 1Kg of cotton requires about 150 Litres of water and 40g reactive dye resulting in a large volume of strongly coloured effluents. This fact in combination with the current water scarcity makes necessary textile waste water reuse. In this paper experimental results obtained from the treatment by different membranes Micro filtration (MF), Nano filtration (NF) and Reverse Osmosis (RO) of Sitex industry waste water pretreated by biological activated sludge are presented and compared. The results obtained from direct Nano filtration performed at different transmembrane pressures (8 - 1 m - 2 for a Volumetric Concentration Factor (VCF) of 4 and that the osmotic pressure π= 4Bars. A high quality of treated effluent in term of colour removal and desalination was obtained for a VCF of 2: salinity retention rate (RR) 57 pour cent and discoloration almost 100 pour cent at pressure of 12 bar. While, the permeate flux obtained using the combination MF/RO at a different pressures 25 - 1 m- 2 for a VCF of 6 indicating an important fouling. In this case, the osmotic pressure varied from 6 to 28 bars. The optimum salinity and colour retention rate (RR) were 86 pour cent and 100 pour cent respectively obtained at a VCF of 2.

  4. An investigation of desalination by nanofiltration, reverse osmosis and integrated (hybrid NF/RO) membranes employed in brackish water treatment.

    Science.gov (United States)

    Talaeipour, M; Nouri, J; Hassani, A H; Mahvi, A H

    2017-01-01

    As an appropriate tool, membrane process is used for desalination of brackish water, in the production of drinking water. The present study aims to investigate desalination processes of brackish water of Qom Province in Iran. This study was carried out at the central laboratory of Water and Wastewater Company of the studied area. To this aim, membrane processes, including nanofiltration (NF) and reverse osmosis (RO), separately and also their hybrid process were applied. Moreover, water physical and chemical parameters, including salinity, total dissolved solids (TDS), electric conductivity (EC), Na +1 and Cl -1 were also measured. Afterward, the rejection percent of each parameter was investigated and compared using nanofiltration and reverse osmosis separately and also by their hybrid process. The treatment process was performed by Luna domestic desalination device, which its membrane was replaced by two NF90 and TW30 membranes for nanofiltration and reverse osmosis processes, respectively. All collected brackish water samples were fed through membranes NF90-2540, TW30-1821-100(RO) and Hybrid (NF/RO) which were installed on desalination household scale pilot (Luna water 100GPD). Then, to study the effects of pressure on permeable quality of membranes, the simulation software model ROSA was applied. Results showed that percent of the salinity rejection was recorded as 50.21%; 72.82 and 78.56% in NF, RO and hybrid processes, respectively. During the study, in order to simulate the performance of nanofiltartion, reverse osmosis and hybrid by pressure drive, reverse osmosis system analysis (ROSA) model was applied. The experiments were conducted at performance three methods of desalination to remove physic-chemical parameters as percentage of rejections in the pilot plant are: in the NF system the salinity 50.21, TDS 43.41, EC 43.62, Cl 21.1, Na 36.15, and in the RO membrane the salinity 72.02, TDS 60.26, EC 60.33, Cl 43.08, Na 54.41. Also in case of the rejection in

  5. Efficiently Combining Water Reuse and Desalination through Forward Osmosis—Reverse Osmosis (FO-RO Hybrids: A Critical Review

    Directory of Open Access Journals (Sweden)

    Gaetan Blandin

    2016-07-01

    Full Text Available Forward osmosis (FO is a promising membrane technology to combine seawater desalination and water reuse. More specifically, in a FO-reverse osmosis (RO hybrid process, high quality water recovered from the wastewater stream is used to dilute seawater before RO treatment. As such, lower desalination energy needs and/or water augmentation can be obtained while delivering safe water for direct potable reuse thanks to the double dense membrane barrier protection. Typically, FO-RO hybrid can be a credible alternative to new desalination facilities or to implementation of stand-alone water reuse schemes. However, apart from the societal (public perception of water reuse for potable application and water management challenges (proximity of wastewater and desalination plants, FO-RO hybrid has to overcome technical limitation such as low FO permeation flux to become economically attractive. Recent developments (i.e., improved FO membranes, use of pressure assisted osmosis, PAO demonstrated significant improvement in water flux. However, flux improvement is associated with drawbacks, such as increased fouling behaviour, lower rejection of trace organic compounds (TrOCs in PAO operation, and limitation in FO membrane mechanical resistance, which need to be better considered. To support successful implementation of FO-RO hybrid in the industry, further work is required regarding up-scaling to apprehend full-scale challenges in term of mass transfer limitation, pressure drop, fouling and cleaning strategies on a module scale. In addition, refined economics assessment is expected to integrate fouling and other maintenance costs/savings of the FO/PAO-RO hybrid systems, as well as cost savings from any treatment step avoided in the water recycling.

  6. Efficiently Combining Water Reuse and Desalination through Forward Osmosis—Reverse Osmosis (FO-RO) Hybrids: A Critical Review

    Science.gov (United States)

    Blandin, Gaetan; Verliefde, Arne R.D.; Comas, Joaquim; Rodriguez-Roda, Ignasi; Le-Clech, Pierre

    2016-01-01

    Forward osmosis (FO) is a promising membrane technology to combine seawater desalination and water reuse. More specifically, in a FO-reverse osmosis (RO) hybrid process, high quality water recovered from the wastewater stream is used to dilute seawater before RO treatment. As such, lower desalination energy needs and/or water augmentation can be obtained while delivering safe water for direct potable reuse thanks to the double dense membrane barrier protection. Typically, FO-RO hybrid can be a credible alternative to new desalination facilities or to implementation of stand-alone water reuse schemes. However, apart from the societal (public perception of water reuse for potable application) and water management challenges (proximity of wastewater and desalination plants), FO-RO hybrid has to overcome technical limitation such as low FO permeation flux to become economically attractive. Recent developments (i.e., improved FO membranes, use of pressure assisted osmosis, PAO) demonstrated significant improvement in water flux. However, flux improvement is associated with drawbacks, such as increased fouling behaviour, lower rejection of trace organic compounds (TrOCs) in PAO operation, and limitation in FO membrane mechanical resistance, which need to be better considered. To support successful implementation of FO-RO hybrid in the industry, further work is required regarding up-scaling to apprehend full-scale challenges in term of mass transfer limitation, pressure drop, fouling and cleaning strategies on a module scale. In addition, refined economics assessment is expected to integrate fouling and other maintenance costs/savings of the FO/PAO-RO hybrid systems, as well as cost savings from any treatment step avoided in the water recycling. PMID:27376337

  7. The feasibility of nanofiltration membrane bioreactor (NF-MBR)+reverse osmosis (RO) process for water reclamation: Comparison with ultrafiltration membrane bioreactor (UF-MBR)+RO process.

    Science.gov (United States)

    Tay, Ming Feng; Liu, Chang; Cornelissen, Emile R; Wu, Bing; Chong, Tzyy Haur

    2018-02-01

    This study examines the feasibility of a novel nanofiltration membrane bioreactor (NF-MBR) followed by reverse osmosis (RO) process for water reclamation at 90% recovery and using an ultrafiltration MBR (UF-MBR)+RO as baseline for comparison. Both MBRs adopted the same external hollow fiber membrane configurations and operating conditions. The collected permeates of the MBRs were subsequently fed to the respective RO systems. The results showed that the NF-MBR (operated at a constant flux of 10 L/m 2 h) achieved superior MBR permeate quality due to enhanced biodegradation and high rejection capacity of the NF membrane, leading to lower RO fouling rates (∼3.3 times) as compared to the UF-MBR. Further analysis indicated that the cake layer fouling that caused the cake-enhanced osmotic pressure (CEOP) effect contributed predominantly to the transmembrane pressure (TMP) increase in the NF-MBR, while irreversible pore fouling was the major reason for UF membrane fouling. Furthermore, it was found that the biopolymers (i.e., organics with MW > 10 kDa) were the main components present in the foulants of the NF/UF membranes and RO membranes. The analysis indicated that the NF-MBR + RO system at recovery of 90% has comparable energy consumption as the UF-MBR + RO system at recovery of 75%. Our findings proved the feasibility of the NF-MBR + RO for water reclamation at a high recovery rate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Health, Sanitary and Economic Evaluation of Home-like Systems of Water Treatment (Reverse Osmosis, RO in Qom City

    Directory of Open Access Journals (Sweden)

    Mohammadreza Jafaripour

    2011-07-01

    Full Text Available Reverse Osmosis (RO is one of the most useful techniques to improve the elimination of organic and mineral Substances from ground and surface water after primary purification processes such as coagulation, sedimentation and filtration.This System provides the required water quality characteristics to somehow.  However, in selection RO systems civil management decision and general public opinion along with cost and health impact must be considered. This study was done in 2010. Statistical methods have used to gather data about of families who used RO In their private homes and mode of eliminate of the wastewater generated by this process. The results indicated that in the normal operational conditions such as pressure 6- 10 kg / cm2 the, optimum recovery % 30 and flow rate 1lit/min , and water temperature 4- 38C°, an Amount of 14191200 kwh of power energy have been consumed to produce 157680 m3 / year treated water required for 36000 families. This has also generated 367920 m3 / year of wastewater being disposed without any management and environmental considerations. Apart from that more than 198000 of filters have been ejected to the environment. Also regarding health aspects, reducing the hardness and fluoride levels in treated water could be undesirable. It could be concluded that increasing the number of local water distribution points and speeding up the water supplying project from Dez river toQom can decrease the investment on RO system.

  9. Utilization of reverse osmosis (RO) for reuse of MBR-treated wastewater in irrigation-preliminary tests and quality analysis of product water.

    Science.gov (United States)

    Bunani, Samuel; Yörükoğlu, Eren; Sert, Gökhan; Kabay, Nalan; Yüksel, Ümran; Yüksel, Mithat; Egemen, Özdemir; Pek, Taylan Özgür

    2018-02-01

    Membrane bioreactor (MBR) effluent collected from a wastewater treatment plant installed at an industrial zone was used for reverse osmosis (RO) membrane tests in the laboratory. For this, two different GE Osmonics RO membranes (AK-BWRO and AD-SWRO) were employed. The results showed that AK-brackish water reverse osmosis (AK-BWRO) and AD-seawater reverse osmosis (AD-SWRO) membranes have almost similar rejection performances regarding analyzed parameters such as conductivity, salinity, color, chemical oxygen demand (COD), and total organic carbon (TOC). On the other hand, these membranes behaved quite differently considering their permeate water flux at the same applied pressure of 10 bar. AD-SWRO membrane was also tested at 20 bar. The results revealed that AD-SWRO membrane had almost the same rejections either at 10 or at 20 bar of applied pressure. Compared with irrigation water standards, AK-BWRO and AD-SWRO gave an effluent with low salinity value and sodium adsorption ratio (SAR) which makes it unsuitable for irrigation due to the infiltration problems risi0ng from unbalanced values of salinity and SAR. Combination of MBR effluent and RO effluent at respective proportions of 0.3:0.7 and 0.4:0.6 for AK-BWRO and AD-SWRO, respectively, are the optimum mixing ratios to overcome the infiltration hazard problem. Choice of less-sensitive crops to chloride and sodium ions is another strategy to overcome all hazards which may arise from above suggested mixing proportions.

  10. Evaluation of Military Field-Water Quality. Volume 7. Performance Evaluation of the 600-GPH Reverse Osmosis Water Purification Unit (ROWPU): reverse Osmosis (RO) Components

    Science.gov (United States)

    1986-02-01

    about 0.02 Prm according to one report2 or 0,1 pm according to another, 1 1 the sieving process is called microfiltration (MF), Microfiltration membranes...product-water flux when the solutes contained five or more carbon atoms. The product-water flux was restored completely when the solutes were removed from...rejection, affinity for salt-rejection restoratives , chemical stability, and long-term durability. 3 1 Past specifications advertised for the UOP TFC-1501

  11. FATE OF REVERSE OSMOSIS (RO) MEMBRANES DURING OXIDATION BY DISINFECTANTS USED IN WATER TREATMENT: IMPACT ON MEMBRANE STRUCTURE AND PERFORMANCES

    KAUST Repository

    Maugin, Thomas

    2013-12-01

    Providing pretreatment prior RO filtration is essential to avoid biofouling and subsequent loss of membrane performances. Chlorine is known to degrade polymeric membrane, improving or reducing membrane efficiency depending on oxidation conditions. This study aimed to assess the impact of alternative disinfectant, NH2Cl, as well as secondary oxidants formed during chloramination of seawater, e.g. HOBr, HOI, or used in water treatment e.g. ClO2, O3, on membrane structure and performances. Permeability, total and specific rejection (Cl-, SO4 2-, Br-, Boron), FTIR profile, elemental composition were analyzed. Results showed that each oxidant seems to react differently with the membrane. HOCl, HOBr, ClO2 and O3 improved membrane permeability but decreased rejection in different extent. In comparison, chloramines resulted in identical trends but oxidized membrane very slowly. On the contrary, iodine improved membrane rejection e.g. boron, but decreased permeability. Reaction conducted with chlorine, bromine, iodine and chloramines resulted in the incorporation of halogen in the membrane structure. All oxidant except iodine were able to break amide bonds of the membrane structure in our condition. In addition, chloramine seemed to react with membrane differently, involving a potential addition of nitrogen. Chloramination of seawater amplified membrane performances evolutions due to generation of bromochloramine. Moreover, chloramines reacted both with NOM and membrane during oxidation in natural seawater, leading to additional rejection drop.

  12. RO-75, Reverse Osmosis Plant Design Optimization and Cost Optimization

    International Nuclear Information System (INIS)

    Glueckstern, P.; Reed, S.A.; Wilson, J.V.

    1999-01-01

    1 - Description of problem or function: RO75 is a program for the optimization of the design and economics of one- or two-stage seawater reverse osmosis plants. 2 - Method of solution: RO75 evaluates the performance of the applied membrane module (productivity and salt rejection) at assumed operating conditions. These conditions include the site parameters - seawater salinity and temperature, the membrane module operating parameters - pressure and product recovery, and the membrane module predicted long-term performance parameters - lifetime and long flux decline. RO75 calculates the number of first and second stage (if applied) membrane modules needed to obtain the required product capacity and quality and evaluates the required pumping units and the power recovery turbine (if applied). 3 - Restrictions on the complexity of the problem: The program does not optimize or design the membrane properties and the internal structure and flow characteristics of the membrane modules; it assumes operating characteristics defined by the membrane manufacturers

  13. Behavior of pharmaceuticals and drugs of abuse in a drinking water treatment plant (DWTP) using combined conventional and ultrafiltration and reverse osmosis (UF/RO) treatments

    Energy Technology Data Exchange (ETDEWEB)

    Boleda, Ma Rosa [AGBAR-Aiguees de Barcelona, Gral Batet 5-7, 08028 Barcelona (Spain); Galceran, Ma Teresa [University of Barcelona, Department Analytical Chemistry, Av. Diagonal 647, 08028 Barcelona (Spain); Ventura, Francesc, E-mail: fventura@agbar.es [AGBAR-Aiguees de Barcelona, Gral Batet 5-7, 08028 Barcelona (Spain)

    2011-06-15

    The behavior along the potabilization process of 29 pharmaceuticals and 12 drugs of abuse identified from a total of 81 compounds at the intake of a drinking water treatment plant (DWTP) has been studied. The DWTP has a common treatment consisting of dioxychlorination, coagulation/flocculation and sand filtration and then water is splitted in two parallel treatment lines: conventional (ozonation and carbon filtration) and advanced (ultrafiltration and reverse osmosis) to be further blended, chlorinated and distributed. Full removals were reached for most of the compounds. Iopromide (up to 17.2 ng/L), nicotine (13.7 ng/L), benzoylecgonine (1.9 ng/L), cotinine (3.6 ng/L), acetaminophen (15.6 ng/L), erythromycin (2.0 ng/L) and caffeine (6.0 ng/L) with elimination efficiencies {>=}94%, were the sole compounds found in the treated water. The advanced treatment process showed a slightly better efficiency than the conventional treatment to eliminate pharmaceuticals and drugs of abuse. - Highlights: > The presence of pharmaceuticals and drugs of abuse in surface water was demonstrated. > Elimination in both potabilization processes reached levels >99% for most compounds. > Four pharmaceuticals and three drugs of abuse survived the potabilization process. - The efficiency of potabilization processes to eliminate or transform pharmaceuticals and illicit drugs is evaluated.

  14. Behavior of pharmaceuticals and drugs of abuse in a drinking water treatment plant (DWTP) using combined conventional and ultrafiltration and reverse osmosis (UF/RO) treatments

    International Nuclear Information System (INIS)

    Boleda, Ma Rosa; Galceran, Ma Teresa; Ventura, Francesc

    2011-01-01

    The behavior along the potabilization process of 29 pharmaceuticals and 12 drugs of abuse identified from a total of 81 compounds at the intake of a drinking water treatment plant (DWTP) has been studied. The DWTP has a common treatment consisting of dioxychlorination, coagulation/flocculation and sand filtration and then water is splitted in two parallel treatment lines: conventional (ozonation and carbon filtration) and advanced (ultrafiltration and reverse osmosis) to be further blended, chlorinated and distributed. Full removals were reached for most of the compounds. Iopromide (up to 17.2 ng/L), nicotine (13.7 ng/L), benzoylecgonine (1.9 ng/L), cotinine (3.6 ng/L), acetaminophen (15.6 ng/L), erythromycin (2.0 ng/L) and caffeine (6.0 ng/L) with elimination efficiencies ≥94%, were the sole compounds found in the treated water. The advanced treatment process showed a slightly better efficiency than the conventional treatment to eliminate pharmaceuticals and drugs of abuse. - Highlights: → The presence of pharmaceuticals and drugs of abuse in surface water was demonstrated. → Elimination in both potabilization processes reached levels >99% for most compounds. → Four pharmaceuticals and three drugs of abuse survived the potabilization process. - The efficiency of potabilization processes to eliminate or transform pharmaceuticals and illicit drugs is evaluated.

  15. Nanofiltration vs. reverse osmosis for the removal of emerging organic contaminants in water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor; Maeng, Sungkyu; Fujioka, Takahiro; Kennedy, Maria Dolores; Li, Zhenyu; Amya, Gary

    2011-01-01

    Reverse osmosis (RO) in existing water reuse facilities is a water industry standard. However, that approach may be questioned taking into consideration that "tight" NF can be equal or "better" than RO. NF can achieve the same removals of RO

  16. Behavior of pharmaceuticals and drugs of abuse in a drinking water treatment plant (DWTP) using combined conventional and ultrafiltration and reverse osmosis (UF/RO) treatments.

    Science.gov (United States)

    Boleda, M A Rosa; Galceran, M A Teresa; Ventura, Francesc

    2011-06-01

    The behavior along the potabilization process of 29 pharmaceuticals and 12 drugs of abuse identified from a total of 81 compounds at the intake of a drinking water treatment plant (DWTP) has been studied. The DWTP has a common treatment consisting of dioxychlorination, coagulation/flocculation and sand filtration and then water is splitted in two parallel treatment lines: conventional (ozonation and carbon filtration) and advanced (ultrafiltration and reverse osmosis) to be further blended, chlorinated and distributed. Full removals were reached for most of the compounds. Iopromide (up to 17.2 ng/L), nicotine (13.7 ng/L), benzoylecgonine (1.9 ng/L), cotinine (3.6 ng/L), acetaminophen (15.6 ng/L), erythromycin (2.0 ng/L) and caffeine (6.0 ng/L) with elimination efficiencies ≥ 94%, were the sole compounds found in the treated water. The advanced treatment process showed a slightly better efficiency than the conventional treatment to eliminate pharmaceuticals and drugs of abuse. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Integrated removal of inorganic contaminants from acid mine drainage using BOF slag, lime, soda ash and reverse osmosis (RO): Implication for the production of drinking water

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2017-06-01

    Full Text Available softeners will pro- duce water of drinking standard. Acknowledgements The authors wish to express their sincere gratitude to the Council for Scientific and Industrial research (CSIR), Tshwane University of Technology for providing lab space to execute... quality. As such, this study proved that the coupling of RO process to BOF slag and different softeners will produce water of drinking standard. Acknowledgements The authors wish to express their sincere gratitude to the Council for Scientific...

  18. Effectiveness of Subsidies in Technology Adoption: A Case Study Involving Reverse Osmosis (RO Membrane Technology

    Directory of Open Access Journals (Sweden)

    Nur Laili

    2016-12-01

    Full Text Available Adoption of new technologies is a process that involves technological learning and penetration of new products into the market. Within the process of new technologies adoption, government usually intervened by providing incentives, in order to support the technology adoption to be succeed. This paper examines the effectiveness of incentives for the sustainability of reverse osmosis (RO membrane technology adoption. The study conducted through single case study on SWRO installation in Mandangin Island, East Java, Indonesia. Results of case study indentify the existence of government incentive in the form of direct subsidies to decrease the price of clean water. Although successful in reducing the price of water, but effectiveness of the subsidy on the sustainability of SWRO is still low, which is operates only 30% in a year. Further analysis shows that these subsidies actually be counter-productive to the sustainability of SWRO installation.

  19. Reverse osmosis water purification system

    Science.gov (United States)

    Ahlstrom, H. G.; Hames, P. S.; Menninger, F. J.

    1986-01-01

    A reverse osmosis water purification system, which uses a programmable controller (PC) as the control system, was designed and built to maintain the cleanliness and level of water for various systems of a 64-m antenna. The installation operates with other equipment of the antenna at the Goldstone Deep Space Communication Complex. The reverse osmosis system was designed to be fully automatic; with the PC, many complex sequential and timed logic networks were easily implemented and are modified. The PC monitors water levels, pressures, flows, control panel requests, and set points on analog meters; with this information various processes are initiated, monitored, modified, halted, or eliminated as required by the equipment being supplied pure water.

  20. Integrated treatment of acid mine drainage using BOF slag, lime/soda ash and reverse osmosis (RO): Implication for the production of drinking water

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2017-12-01

    Full Text Available -up with environmental friendly and zeroliquid-discharge technologies. The purpose of this novel study was to produce drinking water and recover valuable minerals from acid mine drainage using an integration of Basic Oxygen Furnace (BOF) slag, lime, soda ash and Reverse...

  1. Impact of RO-desalted water on distribution water qualities.

    Science.gov (United States)

    Taylor, J; Dietz, J; Randall, A; Hong, S

    2005-01-01

    A large-scale pilot distribution study was conducted to investigate the impacts of blending different source waters on distribution water qualities, with an emphasis on metal release (i.e. corrosion). The principal source waters investigated were conventionally treated ground water (G1), surface water processed by enhanced treatment (S1), and desalted seawater by reverse osmosis membranes (RO). Due to the nature of raw water quality and associated treatment processes, G1 water had high alkalinity, while S1 and RO sources were characterized as high sulfate and high chloride waters, respectively. The blending ratio of different treated waters determined the quality of finished waters. Iron release from aged cast iron pipes increased significantly when exposed to RO and S1 waters: that is, the greater iron release was experienced with alkalinity reduced below the background of G1 water. Copper release to drinking water, however, increased with increasing alkalinity and decreasing pH. Lead release, on the other hand, increased with increasing chloride and decreasing sulfate. The effect of pH and alkalinity on lead release was not clearly observed from pilot blending study. The flat and compact corrosion scales observed for lead surface exposed to S1 water may be attributable to lead concentration less than that of RO water blends.

  2. Removal of organic micro-pollutants (phenol, aniline and nitrobenzene) via forward osmosis (FO) process: Evaluation of FO as an alternative method to reverse osmosis (RO).

    Science.gov (United States)

    Cui, Yue; Liu, Xiang-Yang; Chung, Tai-Shung; Weber, Martin; Staudt, Claudia; Maletzko, Christian

    2016-03-15

    In this study, we have explored and compared the effectiveness of using (1) lab-fabricated forward osmosis (FO) membranes under both FO and reverse osmosis (RO) modes and (2) commercially available RO membranes under the RO mode for the removal of organic micro-pollutants. The lab-fabricated FO membranes are thin film composite (TFC) membranes consisting of a polyamide layer and a porous substrate cast from three different materials; namely, Matrimid, polyethersulfone (PESU) and sulfonated polyphenylene sulfone (sPPSU). The results show that the FO mode is superior to the RO mode in the removal of phenol, aniline and nitrobenzene from wastewater. The rejections of all three TFC membranes to all the three organic micro-pollutants under the FO processes are higher than 72% and can be even higher than 90% for aniline when a 1000 ppm aromatic aqueous solution and 1 M NaCl are employed as feeds. These performances outperform the results obtained from themselves and commercially available RO membranes under the RO mode. In addition, the rejection can be maintained even when treating a more concentrated feed solution (2000 ppm). The removal performance can be further enhanced by using a more concentrated draw solution (2 M). The water flux is almost doubled, and the rejection increment can reach up to 17%. Moreover, it was observed that annealing as a post-treatment would help compact the membrane selective layer and further enhance the separating efficiency. The obtained organic micro-pollutant rejections and water fluxes under various feasible operating conditions indicate that the FO process has potential to be a viable treatment for wastewater containing organic micro-pollutants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Removal of organic micro-pollutants (phenol, aniline and nitrobenzene) via forward osmosis (FO) process: Evaluation of FO as an alternative method to reverse osmosis (RO)

    KAUST Repository

    Cui, Yue

    2016-01-05

    In this study, we have explored and compared the effectiveness of using (1) lab-fabricated forward osmosis (FO) membranes under both FO and reverse osmosis (RO) modes and (2) commercially available RO membranes under the RO mode for the removal of organic micro-pollutants. The lab-fabricated FO membranes are thin film composite (TFC) membranes consisting of a polyamide layer and a porous substrate cast from three different materials; namely, Matrimid, polyethersulfone (PESU) and sulfonated polyphenylene sulfone (sPPSU). The results show that the FO mode is superior to the RO mode in the removal of phenol, aniline and nitrobenzene from wastewater. The rejections of all three TFC membranes to all the three organic micro-pollutants under the FO processes are higher than 72% and can be even higher than 90% for aniline when a 1000 ppm aromatic aqueous solution and 1 M NaCl are employed as feeds. These performances outperform the results obtained from themselves and commercially available RO membranes under the RO mode. In addition, the rejection can be maintained even when treating a more concentrated feed solution (2000 ppm). The removal performance can be further enhanced by using a more concentrated draw solution (2 M). The water flux is almost doubled, and the rejection increment can reach up to 17%. Moreover, it was observed that annealing as a post-treatment would help compact the membrane selective layer and further enhance the separating efficiency. The obtained organic micro-pollutant rejections and water fluxes under various feasible operating conditions indicate that the FO process has potential to be a viable treatment for wastewater containing organic micro-pollutants.

  4. Installations for water desalination by reverse osmosis. P. 2

    International Nuclear Information System (INIS)

    Bauermann, H.D.; Ermert, U.

    1974-01-01

    Starting with the explanation of an installation scheme of a reverse osmosis (RO) plant for water desalination, the various parts of such a plant are firstly discussed briefly. After a chapter dealing with the feed pre-treatment required, the operation of RO-plants is dealt with. The usual variations of arrangement are shown, as well as some information given on maintenance and costs of such methods of desalination. The last part contains some examples of plants installed so far. (orig.) [de

  5. Water Desalination Studies Using Forward Osmosis Technology, A Review

    International Nuclear Information System (INIS)

    Abou El-Nour, F.H.

    2016-01-01

    Fresh water and energy shortage represent a great challenge facing the whole world now. To cover the global water demand, an energy-efficient approach is required to be applied in the suitable technology to achieve the shortage in the fresh water demand. Different techniques are used to solve this problem. A mong the different methods applied to desalinate seawater is the osmosis technologies . Although reversible osmosis (RO) is the most familiar method used for this purpose, forward osmosis (FO) represents a more suitable technique due to several arguments including low energy cost. The present study represents the use of FO technique for water desalination with adsorption regeneration. In this respect, a self-prepared granular active carbon produced from dates is to be used as an adsorbent agent. The physical characteristics of the active carbon are studied such as BET specific surface area, pore size, particle size and the structure using scanning electron microscope (SEM). Different advanced apparatus are used for such measurements. In addition, the adsorption is otherms (Langmuier and Freundlich) are established to explain the adsorption mechanism of the process. Accordingly, the review includes essential information and sufficient backgrounds in the field of desalination using FO or simply direct osmosis, which overcome the different difficulties present in reversible RO

  6. A Comprehensive Study on the Application of Reverse Osmosis (RO Technology for the Petroleum Industry Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Shahryar Jafarinejad

    2017-10-01

    Full Text Available Large quantities of oily wastewaters can be generated from the activities and processes in the petroleum industry which draining of these effluents not only pollutes the environment but also reduces the yield of oil and water. Therefore, development of treatment processes for petroleum industry wastewaters is vital in order to prevent serious environmental damage and provide a source of water for beneficial use. Reverse osmosis (RO can be the most common membrane process used for desalination from oily wastewater and can produce water suitable for reuse at the petroleum industry. In this study, the application of RO technology for the petroleum industry wastewater treatment in different laboratory, pilot, field, and industrial scales have been reviewed. In addition, membrane fouling control, performance efficiency, treatment system configurations, pretreatment methods, quality of treated water, and economic issues have been investigated. With mixtures as complex as petroleum industry wastewaters, membrane fouling becomes a significant hurdle to implement the RO-based purification system. Operating the system within the critical flux range or adding chemicals, and/or pretreatment can usually control membrane fouling. Salt rejection of RO membranes can be 99% or higher.

  7. Rotating Reverse-Osmosis for Water Purification

    Science.gov (United States)

    Lueptow, RIchard M.

    2004-01-01

    A new design for a water-filtering device combines rotating filtration with reverse osmosis to create a rotating reverse- osmosis system. Rotating filtration has been used for separating plasma from whole blood, while reverse osmosis has been used in purification of water and in some chemical processes. Reverse- osmosis membranes are vulnerable to concentration polarization a type of fouling in which the chemicals meant not to pass through the reverse-osmosis membranes accumulate very near the surfaces of the membranes. The combination of rotating filtration and reverse osmosis is intended to prevent concentration polarization and thereby increase the desired flux of filtered water while decreasing the likelihood of passage of undesired chemical species through the filter. Devices based on this concept could be useful in a variety of commercial applications, including purification and desalination of drinking water, purification of pharmaceutical process water, treatment of household and industrial wastewater, and treatment of industrial process water. A rotating filter consists of a cylindrical porous microfilter rotating within a stationary concentric cylindrical outer shell (see figure). The aqueous suspension enters one end of the annulus between the inner and outer cylinders. Filtrate passes through the rotating cylindrical microfilter and is removed via a hollow shaft. The concentrated suspension is removed at the end of the annulus opposite the end where the suspension entered.

  8. A new approach for determination of fouling potential by colloidal nanoparticles during reverse osmosis (RO) membrane filtration of seawater

    International Nuclear Information System (INIS)

    Park, Ji Yeon; Lim, Sungil; Park, Kihong

    2013-01-01

    A direct measurement of number concentration of colloidal nanoparticles (15–450 nm) in water was made with the membrane filtration-differential mobility analyzer technique, and its corresponding flux decline rate (FDR) was determined by laboratory-scale RO fouling test unit using varying number concentrations of silica nanoparticles in artificial seawaters. This relationship was used to predict fouling potential of colloidal nanoparticles in reverse osmosis (RO) membrane process of seawaters in RO plant. It was found that the FDR linearly increased with the increasing number of colloidal nanoparticles for the given concentration range and that the relationship between the number concentration and the FDR also depended on RO membrane surface properties. Data for estimated FDR values for natural seawaters after pretreatment showed a clear difference among samples, which is contrary to the pre-existing index such as silt density index and modified fouling index. Our data suggest that measurement of colloidal nanoparticles is useful for selection of proper pretreatment and successful operation of RO membrane process along with other particle fouling predictors accounting for large particles (>450 nm).

  9. A new approach for determination of fouling potential by colloidal nanoparticles during reverse osmosis (RO) membrane filtration of seawater

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji Yeon; Lim, Sungil; Park, Kihong, E-mail: kpark@gist.ac.kr [Gwangju Institute of Science and Technology (GIST), School of Environmental Science and Engineering (Korea, Republic of)

    2013-04-15

    A direct measurement of number concentration of colloidal nanoparticles (15-450 nm) in water was made with the membrane filtration-differential mobility analyzer technique, and its corresponding flux decline rate (FDR) was determined by laboratory-scale RO fouling test unit using varying number concentrations of silica nanoparticles in artificial seawaters. This relationship was used to predict fouling potential of colloidal nanoparticles in reverse osmosis (RO) membrane process of seawaters in RO plant. It was found that the FDR linearly increased with the increasing number of colloidal nanoparticles for the given concentration range and that the relationship between the number concentration and the FDR also depended on RO membrane surface properties. Data for estimated FDR values for natural seawaters after pretreatment showed a clear difference among samples, which is contrary to the pre-existing index such as silt density index and modified fouling index. Our data suggest that measurement of colloidal nanoparticles is useful for selection of proper pretreatment and successful operation of RO membrane process along with other particle fouling predictors accounting for large particles (>450 nm).

  10. Beneficial phosphate recovery from reverse osmosis (RO) concentrate of an integrated membrane system using polymeric ligand exchanger (PLE).

    Science.gov (United States)

    Kumar, Manish; Badruzzaman, Mohammad; Adham, Samer; Oppenheimer, Joan

    2007-05-01

    Phosphorus (P) discharge to surface water is a major environmental problem. Wastewater treatment is targeted towards removal of this nutrient to prevent degradation of surface water. Integrated membrane systems (IMS) are increasingly being considered for wastewater reclamation, and provide excellent removal of P compounds. However, reverse osmosis (RO), which forms an integral part of these IMSs, concentrates most dissolved substances including P-species such as phosphates in the RO waste stream. In this study, removal of phosphate from this stream using polymeric ligand exchange (PLE) resins was investigated. Further, the possibility of phosphate recovery through struvite (MgNH(4)PO(4).6H(2)O) precipitation was tested. Struvite has been promoted as a slow release fertilizer in recent years. This study demonstrates that PLEs can be successfully used to remove phosphate from RO-concentrate, and to recover more than 85% of the adsorbed phosphorus from the exhausted media and precipitated as a beneficial product (struvite). The approach, presented in this study, suggests advantages of providing economic benefit from a waste product (RO) while avoiding phosphorus discharge to the environment.

  11. Purification of Drinking Water from Fluorides by Reverse Osmosis

    Directory of Open Access Journals (Sweden)

    Aleksander A.

    2018-03-01

    Full Text Available Introduction: An important task in the sphere of sanitary and epidemiological welfare of the population of the Russian Federation is provision of drinking water. Tap water must not contain pathogenic bacteria and dangerous chemicals. Purification systems regulate the concentration of fluoride ions in drinking water. The aim of this paper is to study the possibility of purifying tap water from fluoride ions by reverse osmosis. Materials and Methods: We used the Alfa Laval PilotUnit 2.5 "RO/NF with a set of spiral-type membrane elements RO99-2517/48 to remove fluoride ions. We measured the concentration of fluoride ions by the potentiometric method using the Hanna HI 2211 (pH/mV/T. Fluoride-selective electrode ELIS 131 F was used as an indicator electrode and the standard chloride-silver electrode EVL-1M3 was used as a reference electrode. Both the calibration and buffer solutions were prepared from chemically pure reagents and A. R. purity for analysis reagents according to GOST 4386-89. Results: A single passage of water through the reverse osmosis membrane reduced the concentration of fluoride ions from 2.29 ± 0.02 to 0.240 ± 0.015 mg/l. Double passage of water reduced the concentration by a factor of two. As the concentration of fluoride ions increased in the retentate, the concentration in the filtrate slightly increased too. Purification of water reduced the concentration of fluoride ions from 20 mg/l, to 0.5 mg/l. Discussion and Conclusions: Thus, using the Alfa Laval PilotUnit 2.5" RO/NF with a set of spiral-type membrane elements RO99-2517/48 filters tap water of ions of fluoride to the maximum allowable concentration. This study opens the perspective of using reverse osmosis to purify tap water with high concentration of fluoride ions.

  12. Feasibility of municipal solid waste (MSW as energy sources for Saudi Arabia’s future Reverse osmosis (RO desalination plants

    Directory of Open Access Journals (Sweden)

    Agboola Phillips O.

    2016-12-01

    Full Text Available The Kingdom of Saudi Arabia (KSA generates between 1.4–1.75 kg/person/day of Municipal Solid Waste (MSW that accounts for over 16 million tons of MSW/year. The solid waste collected from different sources is dumped in landfills, thereby creating environmental concerns. In this paper, the potential of solid waste as an energy source (Waste to Energy (WTE for Reverse Osmosis (RO water purification was evaluated. The KSA is known for its acute fresh water shortages and uses desalination technology in meeting its daily water requirements; a process that is energy intensive. The evaluation of the energy content of MSW shows a potential to produce about 927 MW in 2015, based on a total mass burn, and about 1,692 MW in 2032. The MSW-WTE plants can produce about 1.5% of the targeted 120 GW of energy for 2032. For the R.O system, it will give approximately 16.8% of the daily fresh water needed for total mass burn and 2.4% with the recycling option.

  13. Reclaiming Water from Wastewater using Forward Osmosis

    NARCIS (Netherlands)

    Lutchmiah, K.

    2014-01-01

    Water scarcity is a global issue and waste accumulation is a steadily growing one. The innovative Sewer Mining concept, described in this thesis, is an example of an integrated forward osmosis application which incorporates different technologies to attain one goal: water recovery from wastewater,

  14. Water Quality of Hills Water, Supply Water and RO Water Machine at Ulu Yam Selangor

    Science.gov (United States)

    Ngadiman, N.; ‘I Bahari, N.; Kaamin, M.; Hamid, N. B.; Mokhtar, M.; Sahat, S.

    2016-07-01

    The rapid development resulted in the deterioration of the quality of drinking water in Malaysia. Recognizing the importance of water quality, new alternatives for drinking water such as mineral water processing from reverse osmosis (RO) machine become more popular. Hence, the demand for mineral water, natural spring water or water from the hills or mountains rose lately. More consumers believed the quality of these spring water better than other source of drinking water. However, the quality of all the drinking water sources is to meet the required quality standard. Therefore, this paper aims to measure the quality of the waters from hills, from RO machine and the water supply in Ulu Yam, Selangor Batang Kali, Malaysia. The water quality was determined based on following parameters: ammoniacal nitrogen (NH3), iron (Fe), turbidity (NTU) and pH. The results show that the water from hills has better quality compared to water supply and water from RO machine. The value of NH3 ranged from 0.03 mg/L- 0.67 mg/L; Fe was from 0.03mg/L - 0.12 mg/L, turbidity at 0.42 NTU - 0.88 NTU and pH is at 6.60 - 0.71. Based on the studied parameters, all three types of water are fit for drinking and have met the required national drinking water quality standard.

  15. Treatment of low level waste water by reverse osmosis

    International Nuclear Information System (INIS)

    Li Kaijun; Zhang Chuanzhi; Xue Qinhua; Liu Meijun

    1987-11-01

    A Study on the removal of certain radioactive elements Such as 141 Ce, 51 Cr 134 Cu, 106 Ru and 131 I by Reverse Osmosis and the effect of surface activity agent on property of membrance are described in this paper. RO model is carried out to examine the treatment of actual reactor waste water and radioactive laundry waste water. The removal efficiency of total β is 98%. Three preprocessing (cloth pocket filtrator, hivefiltrator and zone) and membrane cleaning methods (acid, ozone and spongeball) are also investigated

  16. Gray water recycle: Effect of pretreatment technologies on low pressure reverse osmosis treatment

    Science.gov (United States)

    Gray water can be a valuable source of water when properly treated to reduce the risks associated with chemical and microbial contamination to acceptable levels for the intended reuse application. In this study, the treatment of gray water using low pressure reverse osmosis (RO) filtration after pre...

  17. Indirect desalination of Red Sea water with forward osmosis and low pressure reverse osmosis for water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor; Li, Zhenyu; Valladares Linares, Rodrigo; Li, Qingyu; Amy, Gary L.

    2011-01-01

    The use of energy still remains the main component of the costs of desalting water. Forward osmosis (FO) can help to reduce the costs of desalination, and extracting water from impaired sources can be beneficial in this regard. Experiments with FO membranes using a secondary wastewater effluent as a feed water and Red Sea water as a draw solution demonstrated that the technology is promising. FO coupled with low pressure reverse osmosis (LPRO) was implemented for indirect desalination. The system consumes only 50% (~1.5 kWh/m3) of the energy used for high pressure seawater RO (SWRO) desalination (2.5-4 kWh/m3), and produces a good quality water extracted from the impaired feed water. Fouling of the FO membranes was not a major issue during long-term experiments over 14 days. After 10 days of continuous FO operation, the initial flux declined by 28%. Cleaning the FO membranes with air scouring and clean water recovered the initial flux by 98.8%. A cost analysis revealed FO per se as viable technology. However, a minimum average FO flux of 10.5 L/m2-h is needed to compete with water reuse using UF-LPRO, and 5.5 L/m2-h is needed to recover and desalinate water at less cost than SWRO. © 2011 Elsevier B.V.

  18. Indirect desalination of Red Sea water with forward osmosis and low pressure reverse osmosis for water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor

    2011-10-01

    The use of energy still remains the main component of the costs of desalting water. Forward osmosis (FO) can help to reduce the costs of desalination, and extracting water from impaired sources can be beneficial in this regard. Experiments with FO membranes using a secondary wastewater effluent as a feed water and Red Sea water as a draw solution demonstrated that the technology is promising. FO coupled with low pressure reverse osmosis (LPRO) was implemented for indirect desalination. The system consumes only 50% (~1.5 kWh/m3) of the energy used for high pressure seawater RO (SWRO) desalination (2.5-4 kWh/m3), and produces a good quality water extracted from the impaired feed water. Fouling of the FO membranes was not a major issue during long-term experiments over 14 days. After 10 days of continuous FO operation, the initial flux declined by 28%. Cleaning the FO membranes with air scouring and clean water recovered the initial flux by 98.8%. A cost analysis revealed FO per se as viable technology. However, a minimum average FO flux of 10.5 L/m2-h is needed to compete with water reuse using UF-LPRO, and 5.5 L/m2-h is needed to recover and desalinate water at less cost than SWRO. © 2011 Elsevier B.V.

  19. Assessment of silt density index (SDI) as fouling propensity parameter in reverse osmosis (RO) desalination systems

    KAUST Repository

    Rachman, Rinaldi; Ghaffour, NorEddine; Wali, F.; Amy, Gary L.

    2013-01-01

    Due to its simplicity, silt density index (SDI) is extensively used in reverse osmosis systems despite its limitations in predicting membrane fouling. Employing a reliable fouling index with good reproducibility and precision is necessary. The aim of this investigation is to assess the reliability of SDI in order to understand the reasons for the low level of precision and accuracy. Different commercial SDI membranes and feed water quality were used in this study. Results showed the existence of membrane properties' variation within manufacturers, which then causes a lack of accuracy in fouling risk estimation. The nature of particles during SDI filtration provides information that particle concentration and size play a significant role in SDI quantification with substantial representation given by particles with size close to membrane nominal pore size. Moreover, turbidity-assisted SDI measurements along with determination of ultrafiltration permeate and clean water fouling potential, establish the indication of nonfouling-related phenomena involved on SDI measurement such as natural organic matter adsorption and hydrodynamic conditions that alters during filtration. Additionally, it was found that the latter affects the sensitivity of SDI by being represented by some portions of SDI values. © 2013 Desalination Publications.

  20. Assessment of silt density index (SDI) as fouling propensity parameter in reverse osmosis (RO) desalination systems

    KAUST Repository

    Rachman, Rinaldi

    2013-01-01

    Due to its simplicity, silt density index (SDI) is extensively used in reverse osmosis systems despite its limitations in predicting membrane fouling. Employing a reliable fouling index with good reproducibility and precision is necessary. The aim of this investigation is to assess the reliability of SDI in order to understand the reasons for the low level of precision and accuracy. Different commercial SDI membranes and feed water quality were used in this study. Results showed the existence of membrane properties\\' variation within manufacturers, which then causes a lack of accuracy in fouling risk estimation. The nature of particles during SDI filtration provides information that particle concentration and size play a significant role in SDI quantification with substantial representation given by particles with size close to membrane nominal pore size. Moreover, turbidity-assisted SDI measurements along with determination of ultrafiltration permeate and clean water fouling potential, establish the indication of nonfouling-related phenomena involved on SDI measurement such as natural organic matter adsorption and hydrodynamic conditions that alters during filtration. Additionally, it was found that the latter affects the sensitivity of SDI by being represented by some portions of SDI values. © 2013 Desalination Publications.

  1. Plant experience with temporary reverse osmosis makeup water systems

    International Nuclear Information System (INIS)

    Polidoroff, C.

    1986-01-01

    Pacific Gas and Electric (PG and E) Company's Diablo Canyon Power Plant (DCPP), which is located on California's central coast, has access to three sources of raw water: creek water, well water, and seawater. Creek and well water are DCPP's primary sources of raw water; however, because their supply is limited, these sources are supplemented with seawater. The purpose of this paper is to discuss the temporary, rental, reverse osmosis systems used by PG and E to process DCPP's raw water into water suitable for plant makeup. This paper addresses the following issues: the selection of reverse osmosis over alternative water processing technologies; the decision to use vendor-operated temporary, rental, reverse osmosis equipment versus permanent PG and E-owned and -operated equipment; the performance of DCPP's rental reverse osmosis systems; and, the lessons learned from DCPP's reverse osmosis system rental experience that might be useful to other plants considering renting similar equipment

  2. Characterization and biotoxicity assessment of dissolved organic matter in RO concentrate from a municipal wastewater reclamation reverse osmosis system.

    Science.gov (United States)

    Sun, Ying-Xue; Gao, Yue; Hu, Hong-Ying; Tang, Fang; Yang, Zhe

    2014-12-01

    Reverse osmosis (RO) concentrate from municipal wastewater reclamation reverse osmosis (mWRRO) system containing organic compounds may associate with toxic risk, and its discharge might pose an environmental risk. To identify a basis for the selection of feasible technology in treating RO concentrates, the characteristics and biotoxicity of different fractions of dissolved organic matter (DOM) in RO concentrates from an mWRRO system were investigated. The results indicated that the hydrophilic neutrals (HIN), hydrophobic acids (HOA) and hydrophobic bases (HOB) accounted for 96% of the dissolved organic carbon (DOC) of the total DOM in the RO concentrate. According to the SEC chromatograph detected at 254 nm wavelength of UV, the DOM with molecular weight (MW) 1-3 kDa accounted for the majority of the basic and neutral fractions. The fluorescence spectra of the excitation emission matrix (EEM) indicated that most aromatic proteins, humic/fulvic acid-like and soluble microbial by-product-like substances existed in the fractions HOA and hydrophobic neutrals (HON). The genotoxicity and anti-estrogenic activity of the RO concentrate were 1795.6 ± 57.2 μg 4-NQOL(-1) and 2.19 ± 0.05 mg TAM L(-1), respectively. The HIN, HOA, and HOB contributed to the genotoxicity of the RO concentrate, and the HIN was with the highest genotoxic level of 1007.9 ± 94.8 μg 4-NQOL(-1). The HOA, HON, and HIN lead to the total anti-estrogenic activity of the RO concentrate, and HOA occupied approximately 60% of the total, which was 1.3 ± 0.17 mg TAM L(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Arsenic removal in drinking water by reverse osmosis

    OpenAIRE

    Ahmad, Md. Fayej

    2012-01-01

    Arsenic is widely distributed in nature in the air, water and soil. Acute and chronic arsenic exposure by drinking water has been reported in many countries, especially Argentina, Bangladesh, India, Mexico, Mongolia, Thailand and Taiwan. There are many techniques used to remove arsenic from drinking water. Among them reverse osmosis is widely used. Therefore the purpose of this study is to find the conditions favorable for removal of arsenic from drinking water by using reverse osmosis ...

  4. Fluoride Removal from Water by Reverse Osmosis Membrane

    Directory of Open Access Journals (Sweden)

    Sara Namavar

    2013-09-01

    Full Text Available As fluoride concentration in drinking water is one of the effective parameters in human health, finding the way to remove excess amount of fluoride from drinking water is very important in water supply projects. Today, with developing in technology and finding new methods, the use of membrane technology for producing fresh water get improved. In this study the efficiency of reverse osmosis method to remove fluoride from water was investigated. Initial concentration of fluoride, sulfate and electrical conductivity in feed water and the effect of associated cation with fluoride ion were studied. All tests adapted from “Standard Methods for Examination of Water and Wastewater”. Determination of fluoride concentration was done according the standard SPANDS method by using a spectrophotometer DR/5000. Obtain results show that with increasing in concentration of fluoride and sulfate and electrical conductivity in feed water the efficiency of RO membrane to remove fluoride reduced. In addition, this efficiency for CaF2 was higher than NaF.

  5. Osmotic versus conventional membrane bioreactors integrated with reverse osmosis for water reuse: Biological stability, membrane fouling, and contaminant removal.

    Science.gov (United States)

    Luo, Wenhai; Phan, Hop V; Xie, Ming; Hai, Faisal I; Price, William E; Elimelech, Menachem; Nghiem, Long D

    2017-02-01

    This study systematically compares the performance of osmotic membrane bioreactor - reverse osmosis (OMBR-RO) and conventional membrane bioreactor - reverse osmosis (MBR-RO) for advanced wastewater treatment and water reuse. Both systems achieved effective removal of bulk organic matter and nutrients, and almost complete removal of all 31 trace organic contaminants investigated. They both could produce high quality water suitable for recycling applications. During OMBR-RO operation, salinity build-up in the bioreactor reduced the water flux and negatively impacted the system biological treatment by altering biomass characteristics and microbial community structure. In addition, the elevated salinity also increased soluble microbial products and extracellular polymeric substances in the mixed liquor, which induced fouling of the forward osmosis (FO) membrane. Nevertheless, microbial analysis indicated that salinity stress resulted in the development of halotolerant bacteria, consequently sustaining biodegradation in the OMBR system. By contrast, biological performance was relatively stable throughout conventional MBR-RO operation. Compared to conventional MBR-RO, the FO process effectively prevented foulants from permeating into the draw solution, thereby significantly reducing fouling of the downstream RO membrane in OMBR-RO operation. Accumulation of organic matter, including humic- and protein-like substances, as well as inorganic salts in the MBR effluent resulted in severe RO membrane fouling in conventional MBR-RO operation. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  6. Chemical evaluation and treatment of ground water for university town Peshawar, Pakistan by reverse osmosis technology

    International Nuclear Information System (INIS)

    Saddique, M.; Gilani, S.N.; Ishaq, M.; Gul, F.

    2012-01-01

    Present study is focused on the ground water treatment for the University Town Peshawar by reverse osmosis technology, based on the principle of reverse-osmosis pure water and ultra pure water filtration. Water collected from three locations was analyzed. The results showed that the first two water samples were neutral having pH 7.09 and 7.16 comparable with the range (6.50-8.50), while the pH for the water sample getting purified and passed from RO process was 5.33 i.e. slightly acidic. The ionic content of the water sample was low, whereas the conductivity ranged from 624-634 micro S/cm for the first two samples and reduced to 1.37 muS/cm. The parameters investigated are below the safety baseline levels of the national and international standards with the exception of Pb. (author)

  7. EFFICIENCY OF DOMESTIC REVERSE OSMOSIS IN REMOVAL OF TRIHALOMETHANES FROM DRINKING WATER

    Directory of Open Access Journals (Sweden)

    S. Mazloomi ، R. Nabizadeh ، S. Nasseri ، K. Naddafi ، S. Nazmara ، A. H. Mahvi

    2009-10-01

    Full Text Available The reaction of disinfectants with natural organic matters existing in water lead to the formation of Disinfection By-Products. Potentially hazardous and carcinogenic characteristics of trihalomethanes (THMs are recognized. Thus removal of THMs or its precursors are necessary for human health. The aim of this study was to study the efficiency of domestic reverse osmosis (RO in removal of trihalomethanes from drinking water. A pilot scale of RO system with Polyamide membrane as Spiral-Wound, Tape wrapping module was used. Feed solution was made by using of pure chloroform. The samples containing chloroform were analyzed using a gas chromatograph equipped with a flame ionization detector. By increasing the flow, the removal rate of chloroform decreased and with declining removal of EC, the removal of chloroform declined too. In this research, at the worst condition, the efficiency of the pilot scale reverse osmosis reached to 80 % removal of chloroform.

  8. Nanofiltration vs. reverse osmosis for the removal of emerging organic contaminants in water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor

    2011-10-01

    Reverse osmosis (RO) in existing water reuse facilities is a water industry standard. However, that approach may be questioned taking into consideration that "tight" NF can be equal or "better" than RO. NF can achieve the same removals of RO membranes when dealing with emerging organic contaminants (pharmaceuticals, pesticides, endocrine disruptors and others). Experiments using 18 emerging contaminants were performed using membranes NF200 and NF90 at bench-scale units, and for a more complete study, results of NF and RO pilot and full-scale experiments where compared to our experimental results. The removal results showed that NF can remove many emerging contaminants. The average removal by tight NF was 82% for neutral contaminants and 97% for ionic contaminants. The average removal by RO was 85% for neutral contaminants and 99% for ionic contaminants. Aquifer recharge and recovery (ARR) followed by NF can effectively remove emerging contaminants with removals over 90% when loose NF membranes are used.

  9. On a novel strategy for water recovery and recirculation in biorefineries through application of forward osmosis membranes

    DEFF Research Database (Denmark)

    Kalafatakis, Stavros; Braekevelt, Sylvie; Carlsen, Vilhelmsen

    2017-01-01

    A great amount of research has been performed during the last 10 years focusing on forward osmosis (FO)processes. The main driving force is to find an effective and low energy demanding methodology for water recovery as well as up-concentration of valuable products. Nevertheless, the energetic...... and financial benefits of this technology can be undermined from the fact that FO should be usually coupled with reverse osmosis (RO) for subsequent water purification and draw solution regeneration. Hence, a different approach was applied in order to omit the RO step. Crude glycerol and enzymatically...... pretreated wheat straw, which are common 2nd generation biorefinery feedstocks, have been evaluated as possible draw solution. In this way, water can be directly recovered and transferred back into the fermentation loop without further purification. Applying the Aquaporin InsideTM Forward Osmosis system...

  10. Forward osmosis :a new approach to water purification and desalination.

    Energy Technology Data Exchange (ETDEWEB)

    Miller, James Edward; Evans, Lindsey R.

    2006-07-01

    Fresh, potable water is an essential human need and thus looming water shortages threaten the world's peace and prosperity. Waste water, brackish water, and seawater have great potential to fill the coming requirements. Unfortunately, the ability to exploit these resources is currently limited in many parts of the world by both the cost of the energy and the investment in equipment required for purification/desalination. Forward (or direct) osmosis is an emerging process for dewatering aqueous streams that might one day help resolve this problem. In FO, water from one solution selectively passes through a membrane to a second solution based solely on the difference in the chemical potential (concentration) of the two solutions. The process is spontaneous, and can be accomplished with very little energy expenditure. Thus, FO can be used, in effect, to exchange one solute for a different solute, specifically chosen for its chemical or physical properties. For desalination applications, the salts in the feed stream could be exchanged for an osmotic agent specifically chosen for its ease of removal, e.g. by precipitation. This report summarizes work performed at Sandia National Laboratories in the area of FO and reviews the status of the technology for desalination applications. At its current state of development, FO will not replace reverse osmosis (RO) as the most favored desalination technology, particularly for routine waters. However, a future role for FO is not out of the question. The ability to treat waters with high solids content or fouling potential is particularly attractive. Although our analysis indicates that FO is not cost effective as a pretreatment for conventional BWRO, water scarcity will likely drive societies to recover potable water from increasingly marginal resources, for example gray water and then sewage. In this context, FO may be an attractive pretreatment alternative. To move the technology forward, continued improvement and

  11. Reverse Osmosis Filter Use and High Arsenic Levels in Private Well Water

    Science.gov (United States)

    George, Christine M.; Smith, Allan H.; Kalman, David A.; Steinmaus, Craig M.

    2013-01-01

    Inorganic arsenic causes cancer, and millions of people worldwide are exposed to arsenic-contaminated water. Regulatory standards for arsenic levels in drinking water generally do not apply to private domestic wells. Reverse osmosis (RO) units commonly are used by well owners to reduce arsenic concentrations, but may not always be effective. In a survey of 102 homes in Nevada, 19 used RO devices. Pre- and post-RO filtration arsenic concentrations averaged 443 μg/l and 87 μg/l, respectively. The average absolute and percent reductions in arsenic concentrations after filtration were 356 μg/l and 79%, respectively. Postfiltration concentrations were higher than 10 μg/l in 10 homes and higher than 100 μg/l in 4 homes. These findings provide evidence that RO filters do not guarantee safe drinking water and, despite regulatory standards, some people continue to be exposed to very high arsenic concentrations. PMID:17867571

  12. Purification and decontamination of a caustic water by reverse osmosis

    International Nuclear Information System (INIS)

    Plock, C.E.; Travis, T.N.

    1981-01-01

    A reverse osmosis pilot plant was used to decontaminate a caustic water containing low concentrations of uranium, plutonium, and americium. The concentrations of the plutonium and americium were less than one picocurie per liter in the product water. The concentrations of the uranium was reduced to 4.4 picocuries per liter in the product water, which is a reduction of greater than 99%. The reverse osmosis pilot plant was operated at a 98% water recovery, which produced 25,000 gallons per day of product water

  13. Removal of organic micro-pollutants (phenol, aniline and nitrobenzene) via forward osmosis (FO) process: Evaluation of FO as an alternative method to reverse osmosis (RO)

    KAUST Repository

    Cui, Yue; Liu, Xiang-Yang; Chung, Neal Tai-Shung; Weber, Martin; Staudt, Claudia; Maletzko, Christian

    2016-01-01

    under the RO mode. In addition, the rejection can be maintained even when treating a more concentrated feed solution (2000 ppm). The removal performance can be further enhanced by using a more concentrated draw solution (2 M). The water flux is almost

  14. Pseudomonas-related populations associated with reverse osmosis in drinking water treatment.

    Science.gov (United States)

    Sala-Comorera, Laura; Blanch, Anicet R; Vilaró, Carles; Galofré, Belén; García-Aljaro, Cristina

    2016-11-01

    Reverse osmosis membrane filtration technology (RO) is used to treat drinking water. After RO treatment, bacterial growth is still observed in water. However, it is not clear whether those microorganisms belong to species that can pose a health risk, such as Pseudomonas spp. The goal of this study is to characterize the bacterial isolates from a medium that is selective for Pseudomonas and Aeromonas which were present in the water fraction before and after the RO. To this end, isolates were recovered over two years and were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. They were then biochemically phenotyped and the population similarity indexes were calculated. The isolates were analysed for their capacity to form biofilms in vitro and antimicrobial susceptibility. There were significant differences between the microbial populations in water before and after RO. Furthermore, the structures of the populations analysed at the same sampling point were similar in different sampling campaigns. Some of the isolates had the capacity to form a biofilm and showed resistance to different antibiotics. A successful level filtration via RO and subsequent recolonization of the membrane with different species from those in the feed water was found. Pseudomonas aeruginosa was not recovered from among the isolates. This study increases the knowledge on the microorganisms present in water after RO treatment, with focus in one of the genus causing problems in RO systems associated with human health risk, Pseudomonas. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Molecular Characterization of the Bacterial Communities in the Different Compartments of a Full-Scale Reverse-Osmosis Water Purification Plant

    NARCIS (Netherlands)

    Bereschenko, L.A.; Heilig, G.H.J.; Nederlof, M.M.; Loosdrecht, M.C.M. van; Stams, A.J.M.; Euverink, G.J.W.

    2008-01-01

    The origin, structure, and composition of biofilms in various compartments of an industrial full-scale reverse-osmosis (RO) membrane water purification plant were analyzed by molecular biological methods. Samples were taken when the RO installation suffered from a substantial pressure drop and

  16. Molecular characterization of the bacterial communities in the different compartments of a full-scale reverse-osmosis water purification plant

    NARCIS (Netherlands)

    Bereschenko, L.A.; Heilig, G.H.J.; Nederlof, M.M.; Loosdracht, van M.C.M.; Stams, A.J.M.; Euverink, G.J.W.

    2008-01-01

    The origin, structure, and composition of biofilms in various compartments of an industrial full-scale reverse-osmosis (RO) membrane water purification plant were analyzed by molecular biological methods. Samples were taken when the RO installation suffered from a substantial pressure drop and

  17. Power generation from water salinity gradient via osmosis and reverse osmosis

    International Nuclear Information System (INIS)

    Ivanov, Milancho

    2015-01-01

    To reduce dependence on fossil fuels, while at the same time to meet the growing energy demands of the world, it is necessary to explore and promote new alternative energy sources. One such type of renewable energy sources, which recently gained greater credibility is the energy extracted from the water salinity gradient, which is also called blue energy. In this research project will be described a new model of osmotic power plant (MIOS plant), which uses a combination of reverse osmosis and osmosis to convert the energy from the water salinity gradient into electricity. MIOS plant can be built as a vessel anywhere on the surface of the oceans or in the form of dam on the land, which will have a huge advantage over existing plants that can be built only on mouths of rivers. (author)

  18. Removal of radionuclides in drinking water by membrane treatment using ultrafiltration, reverse osmosis and electrodialysis reversal

    International Nuclear Information System (INIS)

    Montaña, M.; Camacho, A.; Serrano, I.; Devesa, R.; Matia, L.; Vallés, I.

    2013-01-01

    A pilot plant had been built to test the behaviour of ultrafiltration (UF), reverse osmosis (RO), and electrodialysis reversal (EDR) in order to improve the quality of the water supplied to Barcelona metropolitan area from the Llobregat River. This paper presents results from two studies to reduce natural radioactivity. The results from the pilot plant with four different scenarios were used to design the full-scale treatment plant built (SJD WTP). The samples taken at different steps of the treatment were analysed to determine gross alpha, gross beta and uranium activity. The results obtained revealed a significant improvement in the radiological water quality provided by both membrane techniques (RO and EDR showed removal rates higher than 60%). However, UF did not show any significant removal capacity for gross alpha, gross beta or uranium activities. RO was better at reducing the radiological parameters studied and this treatment was selected and applied at the full scale treatment plant. The RO treatment used at the SJD WTP reduced the concentration of both gross alpha and gross beta activities and also produced water of high quality with an average removal of 95% for gross alpha activity and almost 93% for gross beta activity at the treatment plant. -- Highlights: ► A study with a pilot plant using different membranes technologies was made. ► Big reduction on natural uranium and 40 K by reverse osmosis was found. ► Pilot plant and full-scale treatment plant behave similarly

  19. The effect of flow and chemical corrosion in reverse osmosis over desalinated water

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Jae [Chunnam National Univ., Gwangju (Korea, Republic of); Pak, Byung Gu [Doosan Heavy Industry Co., Tongyoung (Korea, Republic of)

    2015-12-15

    Desalinated water produced by a reverse osmosis (RO) filtering method forms about 22% of total production of desalinated water in the world. However, the RO environment is very corrosive due to the presence of various chemicals for water treatment and the flow of sand particles leading to corrosion. Recently, there has been much effort to substitute cheaper and more corrosion resistant stainless steels for copper based alloys as a valve material in RO. Nevertheless, the effects of chemicals and particles on the corrosion of stainless steels have rarely been studied. Erosion phenomenon was detected under the condition with the flow rate of more than 8ms{sup -1} in spite of the absence of sand particles. In seawater containing sand particles, the erosion in stainless steels was accelerated further.

  20. Improvement of water desalination technologies in reverse osmosis plants

    Science.gov (United States)

    Vysotskii, S. P.; Konoval'chik, M. V.; Gul'ko, S. E.

    2017-07-01

    The strengthening of requirements for the protection of surface-water sources and increases in the cost of reagents lead to the necessity of using membrane (especially, reverse osmosis) technologies of water desalination as an alternative to ion-exchange technologies. The peculiarities of using reverse osmosis technologies in the desalination of waters with an increased salinity have been discussed. An analogy has been made between the dependence of the adsorptive capacity of ion-exchange resins on the reagent consumption during ion exchange and the dependence of the specific ion flux on the voltage in the electrodialysis and productivity of membrane elements on the excess of the pressure of source water over the osmotic pressure in reverse osmosis. It has been proposed to regulate the number of water desalination steps in reverse osmosis plants, which makes it possible to flexibly change the productivity of equipment and the level of desalinization, depending on the requirements for the technological process. It is shown that the selectivity of reverse osmotic membranes with respect to bivalent ions (calcium, magnesium, and sulfates) is approximately four times higher than the selectivity with respect to monovalent ions (sodium and chlorine). The process of desalination in reverse osmosis plants depends on operation factors, such as the salt content and ion composition of source water, the salt content of the concentrate, and the temperatures of solution and operating pressure, and the design features of devices, such as the length of the motion of the desalination water flux, the distance between membranes, and types of membranes and turbulators (spacers). To assess the influence of separate parameters on the process of reverse osmosis desalination of water solutions, we derived criteria equations by compiling problem solution matrices on the basis of the dimensional method, taking into account the Huntley complement. The operation of membrane elements was

  1. Reserve osmosis and its application in water desalination; Osmosis inversa y su aplicacion en la desalacion de las aguas

    Energy Technology Data Exchange (ETDEWEB)

    Lazaro, I. [Departamento de Ingenieria Aplicada, EPS Universidad Murcia, Cartagena (Spain); Almela, L. [Departamento de Quimica Agricola, Universidad de Murcia, Murcia (Spain); Huete, J.

    1996-08-01

    The limited availability of water resources raises two fundamental issues: those of restructuring traditional irrigated land and scarching for new resources to alleviate water shortage. Among the diverse methods that can be utilized for the desalination of water, reverse osmosis is now of great importance. One the advantages of this techniques is that it can be applied equally to big installations as to smaller rural holdings. This paper briefly describes the different methods of desalination, placing emphasis on reverse osmosis. (Author) 8 refs.

  2. Data on daily fluoride intake based on drinking water consumption prepared by household desalinators working by reverse osmosis process.

    Science.gov (United States)

    Karbasdehi, Vahid Noroozi; Dobaradaran, Sina; Esmaili, Abdolhamid; Mirahmadi, Roghayeh; Ghasemi, Fatemeh Faraji; Keshtkar, Mozhgan

    2016-09-01

    In this data article, we evaluated the daily fluoride contents in 20 household desalinators working by reverse osmosis (RO) process in Bushehr, Iran. The concentration levels of fluoride in inlet and outlet waters were determined by the standard SPADNS method using a spectrophotometer (M501 Single Beam Scanning UV/VIS, UK). The fluoride content in outlet waters were compared with EPA and WHO guidelines for drinking water.

  3. Phosphorus and water recovery by a novel osmotic membrane bioreactor-reverse osmosis system.

    Science.gov (United States)

    Luo, Wenhai; Hai, Faisal I; Price, William E; Guo, Wenshan; Ngo, Hao H; Yamamoto, Kazuo; Nghiem, Long D

    2016-01-01

    An osmotic membrane bioreactor-reverse osmosis (OMBR-RO) hybrid system integrated with periodic microfiltration (MF) extraction was evaluated for simultaneous phosphorus and clean water recovery from raw sewage. In this hybrid system, the forward osmosis membrane effectively retained inorganic salts and phosphate in the bioreactor, while the MF membrane periodically bled them out for phosphorus recovery with pH adjustment. The RO process was used for draw solute recovery and clean water production. Results show that phosphorus recuperation from the MF permeate was most effective when the solution pH was adjusted to 10, whereby the recovered precipitate contained 15-20% (wt/wt) of phosphorus. Periodic MF extraction also limited salinity build-up in the bioreactor, resulting in a stable biological performance and an increase in water flux during OMBR operation. Despite the build-up of organic matter and ammonia in the draw solution, OMBR-RO allowed for the recovery of high quality reused water. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  4. Apparatus, System, and Method for Forward Osmosis in Water Reuse

    KAUST Repository

    Yangali-Quintanilla, Victor

    2013-01-03

    An apparatus, system, and method for desalinating water is presented. The invention relates to recovery of water from impaired water sources by using FO and seawater as draw solution (DS). The seawater becomes diluted over time and can be easily desalinated at very low pressures. Thus, a device consumes less energy when recovering water. The apparatus, system and method comprise an immersed forward osmosis cell.

  5. Water permeability of nanoporous graphene at realistic pressures for reverse osmosis desalination

    Energy Technology Data Exchange (ETDEWEB)

    Cohen-Tanugi, David; Grossman, Jeffrey C. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2014-08-21

    Nanoporous graphene (NPG) shows tremendous promise as an ultra-permeable membrane for water desalination thanks to its atomic thickness and precise sieving properties. However, a significant gap exists in the literature between the ideal conditions assumed for NPG desalination and the physical environment inherent to reverse osmosis (RO) systems. In particular, the water permeability of NPG has been calculated previously based on very high pressures (1000–2000 bars). Does NPG maintain its ultrahigh water permeability under real-world RO pressures (<100 bars)? Here, we answer this question by drawing results from molecular dynamics simulations. Our results indicate that NPG maintains its ultrahigh permeability even at low pressures, allowing a permeate water flux of 6.0 l/h-bar per pore, or equivalently 1041 ± 20 l/m{sup 2}-h-bar assuming a nanopore density of 1.7 × 10{sup 13} cm{sup −2}.

  6. Assessment of the extent of bacterial growth in reverse osmosis system for improving drinking water quality.

    Science.gov (United States)

    Park, Se-keun; Hu, Jiang Yong

    2010-01-01

    This study was carried out to assess reverse osmosis (RO) treatment efficacy of drinking water in terms of biological stability in the distribution system. Two flat-sheet RO membranes were used in this study. Experiments were designed to investigate the growth of biofilm and bulk phase bacteria for the RO-treated water flowing through a model distribution system under controlled conditions without disinfectants. RO membranes improved the water quality of drinking water in terms of inorganic, organic and bacterial contents. Organic matter including the fraction available for microbes was efficiently removed by the RO membranes tested. More than 99% of bacterial cells in the tap water was retained by the RO membranes, leaving water. In spite of the low nutrient contents and few cells in the RO permeates, monitoring of the model distribution systems receiving the RO permeates showed that remarkable biofilm accumulation and bulk cell growth occurred in the RO permeate water. In quasi-steady state, the total cell numbers in the biofilm and bulk water were of order 10(3) cells/cm(2) and 10(3) cells/mL, respectively, which were about 2 orders of magnitude lower than those grown in the tap water produced from conventional water treatment. The culturable heterotrophic bacteria constituted a significant part of the total cells (20.7-32.1% in biofilms and 21.3-46.3% in bulk waters). Biofilm maximum density and production rate were of the order 10(4) cells/cm(2) and 10(2) cells/cm(2)/day, respectively. The specific cell growth rate of bacteria in the biofilms was found to be much lower than those in the bulk waters (0.04-0.05 day(-1) versus 0.28-0.36 day(-1)). The overall specific cell growth rate which indicates the growth potential in the whole system was calculated as 0.07-0.08 day(-1), representing a doubling time of 9.1-10.1 days. These observations can be indicative of possibilities for bacterial growth in the RO permeate water with easily assimilable organic carbon

  7. Forward osmosis applied to evaporative cooling make-up water

    Energy Technology Data Exchange (ETDEWEB)

    Nicoll, Peter; Thompson, Neil; Gray, Victoria [Modern Water plc, Guildford (United Kingdom)

    2012-11-15

    Modern Water is in the process of developing a number of forward osmosis based technologies, ranging from desalination to power generation. This paper outlines the progress made to date on the development and commercial deployment of a forward osmosis based process for the production of evaporative cooling tower make-up water from impaired water sources, including seawater. Evaporative cooling requires significant amounts of good quality water to replace the water lost by evaporation, drift and blowdown. This water can be provided by conventional desalination processes or by the use of tertiary treated sewage effluent. The conventional processes are well documented and understood in terms of operation and power consumption. A new process has been successfully developed and demonstrated that provides make-up water directly, using a core platform 'forward osmosis' technology. This new technology shows significant promise in allowing various raw water sources, such as seawater, to be used directly in the forward osmosis step, thus releasing the use of scarce and valuable high grade water for other more important uses. The paper presents theoretical and operational results for the process, where it is shown that the process can produce make-up water at a fraction of the operational expenditure when compared to conventional processes, in particular regarding power consumption, which in some cases may be as low as 15 % compared to competing processes. Chemical additives to the cooling water (osmotic agent) are retained within the process, thus reducing their overall consumption. Furthermore the chemistry of the cooling water does not support the growth of Legionella pneumophila. Corrosion results are also reported. (orig.)

  8. Suitability of second pass RO as a substitute for high quality MSF product water in Nuclear Desalination Demonstration Plant

    International Nuclear Information System (INIS)

    Murugan, V.; Venkatesh, P.; Balasubramanian, C.; Nagaraj, R.; Yadav, Manoj Kumar; Prabhakar, S.; Tewari, P.K.

    2012-01-01

    Nuclear Desalination Demonstration Plant at Kalpakkam consists of both Multi Stage Flash Distillation (MSF) and Seawater Reverse Osmosis (SWRO) process to produce desalinated water. It supplies part of highly pure water from MSF to Madras Atomic Power Station for its boiler feed requirements and remaining water is blend with SWRO product water and sent to other common facilities located inside Kalpakkam campus. A critical techno-economic analysis is carried out to find out the suitability of second pass RO to sustain the availability of highly pure water in case of MSF plant shutdown. (author)

  9. Desalination of brackish mine waters by reverse osmosis

    Energy Technology Data Exchange (ETDEWEB)

    Kepinski, J; Lipinski, K; Chlubek, N; Delyannis, A; Delyannis, E [eds.

    1976-01-01

    The situation concerning the pollution, by excessive salinity, of the main rivers in Poland is analyzed. The significant contribution of saline coal mine waters is evaluated, with emphasis on large quantities of brackish water in new coal mines. The results are given of preliminary experiments undertaken in order to elaborate the suitable technology. Pretreatment, concentration by reverse osmosis and disinfection of the permeate are the proposed steps. The concentrate as obtained is suitable for further utilization by evaporation.

  10. Three-gradual pilot unit of JP3RO for cleanings and concentration of radioactive sewage by method of upturned osmosis

    International Nuclear Information System (INIS)

    Chmielewski, A.G.; Harasimowicz, M.; Tyminski, B.; Zakrzewska-Trznadel, G.

    2001-01-01

    For many years the Institute of Nuclear Chemistry and Technology has worked on the application of different membrane processes to nuclear technology. The experiments with ultrafiltration, ultrafiltration combined with chemical complexation, membrane distillation and reverse osmosis were conducted. Reverse osmosis (RO) as a method for liquid radioactive waste treatment has been examined at laboratory and pilot plant installations. Thr purification of radioactive model solutions as well as liquid low and medium level radioactive waste samples has been examined with various reverse osmotic modules equipped with thin composite polymeric membranes. The experience with the process led to design and construction of the JP3RO industrial plant, 1 m 3 capacity, composed of three RO stages. On the basis of earlier investigations, membrane modules were selected for the plant. The installation is described in this paper, and the results of experiments are presented. The JP3RO installation was included into the system of liquid low and medium-level radioactive wastes treatment at Institute of Nuclear Energy in Swierk. (author)

  11. Reverse osmosis membrane of high urea rejection properties. [water purification

    Science.gov (United States)

    Johnson, C. C.; Wydeven, T. J. (Inventor)

    1980-01-01

    Polymeric membranes suitable for use in reverse osmosis water purification because of their high urea and salt rejection properties are prepared by generating a plasma of an unsaturated hydrocarbon monomer and nitrogen gas from an electrical source. A polymeric membrane is formed by depositing a polymer of the unsaturated monomer from the plasma onto a substrate, so that nitrogen from the nitrogen gas is incorporated within the polymer in a chemically combined form.

  12. The treatment of river water by reverse osmosis

    International Nuclear Information System (INIS)

    Ray, N.J.; Jenkins, M.A.; Coates, A.

    1977-01-01

    The suitability of rod, spirally would and hollow fibre reverse osmosis systems has been assessed for the treatment of River Trent water to produce water of boiler feed quality. Particular attention has been paid to the effects of the suspended solids level of the influent water supply on operating and cleaning regimes. The best performance was given by the rod-type membranes which could be used with relatively dirty water if suitable chemical and/or physical cleaning techniques were applied. However, even this system, requires some form of clarification of the raw supply, and this affects capital and overall running costs. The hollow fibre membrane, which cannot be readily cleaned required an excessively clean water supply to avoid rapid and irreversible loss of output and is unlikely to have full-scale application on this, or similar, water. The spirally wound membranes, whilst not so susceptible to suspended solids as the hollow fibre system, did not tolerate dirty water, and required the raw water to be clarified to a level that is unlikely to be continuously guaranteed. In its current stage of development reverse osmosis is unlikely to give a cost advantage over the main cation/anion exchange stage of present water treatment plant, even for the treatment of waters relatively high in dissolved salts (500 mg kg -1 ). Moreover, conventional pretreatment and final mixed ion-exchange beds would still be required to produce water of boiler feed quality. Reverse osmosis does, however, remove organic species and non reactive silicon; its selection is likely to be dictated by such requirements or where space is at a premium e.g. extensions to existing water treatment plants. (orig.) [de

  13. A comparative study of boron and arsenic (III) rejection from brackish water by reverse osmosis membranes

    KAUST Repository

    Teychene, Benoî t; Collet, Gaelle; Gallard, Hervé ; Croue, Jean Philippe

    2013-01-01

    This study aims to compare at lab-scale the rejection efficiency of several reverse osmosis membranes (RO) toward arsenic (III) and boron during the filtration of a synthetic brackish water. The effect of pH and operating conditions on the rejection of each RO membrane was studied. Two types of membrane were investigated: "brackish water" and "sea water" membranes. Our results showed that the metalloid rejection depends on the membrane type, pH and transmembrane pressure applied. Increasing pH above the dissociation constant (pKa) of each specie improves significantly the metalloid rejection by RO membranes, whatever the membrane type. Moreover, at identical operating conditions (pH, transmembrane pressure), results showed that the brackish water membranes have a higher water flux and exhibit lower metalloid rejection. The highest As(III) rejection value for the tested brackish water membranes was 99% obtained at pH = 9.6 and 40 bars, whereas it was found that the sea water RO membranes could highly reject As(III), more than 99%, even at low pH and low pressure (pH = 7.6 and 24 bars).Regarding Boron rejection, similar conclusions could be drawn. The sea water RO membranes exert higher removal, with a high rejection value above 96% over the tested conditions. More generally, this study showed that, whatever the operating conditions or the tested membranes, the boron and As(III) permeate concentrations are below the WHO guidelines. In addition, new data about the boron and arsenic permeability of each tested RO membrane was brought thanks to a theoretical calculation. © 2012 Elsevier B.V.

  14. A comparative study of boron and arsenic (III) rejection from brackish water by reverse osmosis membranes

    KAUST Repository

    Teychene, Benoît

    2013-02-01

    This study aims to compare at lab-scale the rejection efficiency of several reverse osmosis membranes (RO) toward arsenic (III) and boron during the filtration of a synthetic brackish water. The effect of pH and operating conditions on the rejection of each RO membrane was studied. Two types of membrane were investigated: "brackish water" and "sea water" membranes. Our results showed that the metalloid rejection depends on the membrane type, pH and transmembrane pressure applied. Increasing pH above the dissociation constant (pKa) of each specie improves significantly the metalloid rejection by RO membranes, whatever the membrane type. Moreover, at identical operating conditions (pH, transmembrane pressure), results showed that the brackish water membranes have a higher water flux and exhibit lower metalloid rejection. The highest As(III) rejection value for the tested brackish water membranes was 99% obtained at pH = 9.6 and 40 bars, whereas it was found that the sea water RO membranes could highly reject As(III), more than 99%, even at low pH and low pressure (pH = 7.6 and 24 bars).Regarding Boron rejection, similar conclusions could be drawn. The sea water RO membranes exert higher removal, with a high rejection value above 96% over the tested conditions. More generally, this study showed that, whatever the operating conditions or the tested membranes, the boron and As(III) permeate concentrations are below the WHO guidelines. In addition, new data about the boron and arsenic permeability of each tested RO membrane was brought thanks to a theoretical calculation. © 2012 Elsevier B.V.

  15. Fouling Characterization of Forward Osmosis Biomimetic Aquaporin Membranes Used for Water Recovery from Municipal Wastewater

    DEFF Research Database (Denmark)

    Zarebska, Agata; Petrinic, Irena; Hey, Tobias

    , organic, and biological fouling, membrane characterization is not a trivial task. The aim of this work is to characterize fouling of FO biomimetic aquaporin membranes during water recovery from municipal wastewater. Membrane fouling was characterized using Scanning Electron Microscopy, X-ray Dispersive......Generally more than 99.93% of municipal wastewater is composed of water, therefore water recovery can alleviate global water stress which currently exists. Traditional ways to extract water from wastewater by the use of membrane bioreactors combined with reverse osmosis (RO), or micro...... compared to other pressure driven membrane processes, some fouling can occur. This entails that by reducing fouling, increased FO membrane performance can be expected, thus increasing the economic viability of FO processes. Since various types of fouling might occur in membrane systems such as inorganic...

  16. Reverse Osmosis Optimization

    Energy Technology Data Exchange (ETDEWEB)

    McMordie Stoughton, Kate; Duan, Xiaoli; Wendel, Emily M.

    2013-08-26

    This technology evaluation was prepared by Pacific Northwest National Laboratory on behalf of the U.S. Department of Energy’s Federal Energy Management Program (FEMP). ¬The technology evaluation assesses techniques for optimizing reverse osmosis (RO) systems to increase RO system performance and water efficiency. This evaluation provides a general description of RO systems, the influence of RO systems on water use, and key areas where RO systems can be optimized to reduce water and energy consumption. The evaluation is intended to help facility managers at Federal sites understand the basic concepts of the RO process and system optimization options, enabling them to make informed decisions during the system design process for either new projects or recommissioning of existing equipment. This evaluation is focused on commercial-sized RO systems generally treating more than 80 gallons per hour.¬

  17. Reverse Osmosis Optimization

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-08-01

    This technology evaluation was prepared by Pacific Northwest National Laboratory on behalf of the U.S. Department of Energy’s Federal Energy Management Program (FEMP). The technology evaluation assesses techniques for optimizing reverse osmosis (RO) systems to increase RO system performance and water efficiency. This evaluation provides a general description of RO systems, the influence of RO systems on water use, and key areas where RO systems can be optimized to reduce water and energy consumption. The evaluation is intended to help facility managers at Federal sites understand the basic concepts of the RO process and system optimization options, enabling them to make informed decisions during the system design process for either new projects or recommissioning of existing equipment. This evaluation is focused on commercial-sized RO systems generally treating more than 80 gallons per hour.

  18. Nanofiltration vs. reverse osmosis for the removal of emerging organic contaminants in water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor

    2011-01-01

    Reverse osmosis (RO) in existing water reuse facilities is a water industry standard. However, that approach may be questioned taking into consideration that "tight" NF can be equal or "better" than RO. NF can achieve the same removals of RO membranes when dealing with emerging organic contaminants (pharmaceuticals, pesticides, endocrine disruptors and others). Experiments using 18 emerging contaminants were performed using membranes NF200 and NF90 at bench-scale units, and for a more complete study, results of NF and RO pilot and fullscale experiments where compared to our experimental results. The removal results showed that NF can remove many emerging contaminants. The average removal by tight NF was 82% for neutral contaminants and 97% for ionic contaminants. The average removal by RO was 85% for neutral contaminants and 99% for ionic contaminants. Aquifer recharge and recovery (ARR) followed by NF can effectively remove emerging contaminants with removals over 90% when loose NF membranes are used. © 2011 2011 Desalination Publications. All rights reserved.

  19. Assessment of nanofiltration and reverse osmosis potentialities to recover metals, sulfuric acid, and recycled water from acid gold mining effluent.

    Science.gov (United States)

    Ricci, Bárbara C; Ferreira, Carolina D; Marques, Larissa S; Martins, Sofia S; Amaral, Míriam C S

    This work assessed the potential of nanofiltration (NF) and reverse osmosis (RO) to treat acid streams contaminated with metals, such as effluent from the pressure oxidation process (POX) used in refractory gold ore processing. NF and RO were evaluated in terms of rejections of sulfuric acid and metals. Regarding NF, high sulfuric acid permeation (∼100%), was observed, while metals were retained with high efficiencies (∼90%), whereas RO led to high acid rejections (acid solutions contaminated by metals, such as POX effluent. In this context, a purified acid stream could be recovered in NF permeate, which could be further concentrated in RO. Recovered acid stream could be reused in the gold ore processing or commercialized. A metal-enriched stream could be also recovered in NF retentate and transferred to a subsequent metal recovery stage. In addition, considering the high acid rejection obtained through the proposed system, RO permeate could be used as recycling water.

  20. State of the art and review on the treatment technologies of water reverse osmosis concentrates.

    Science.gov (United States)

    Pérez-González, A; Urtiaga, A M; Ibáñez, R; Ortiz, I

    2012-02-01

    The growing demand for fresh water is partially satisfied by desalination plants that increasingly use membrane technologies and among them reverse osmosis to produce purified water. Operating with water recoveries from 35% to 85% RO plants generate huge volumes of concentrates containing all the retained compounds that are commonly discharged to water bodies and constitute a potentially serious threat to marine ecosystems; therefore there is an urgent need for environmentally friendly management options of RO brines. This paper gives an overview on the potential treatments to overcome the environmental problems associated to the direct discharge of RO concentrates. The treatment options have been classified according to the source of RO concentrates and the maturity of the technologies. For the sake of clarity three different sources of RO concentrates are differentiated i) desalination plants, ii) tertiary processes in WWTP, and iii) mining industries. Starting with traditional treatments such as evaporation and crystallization other technologies that have emerged in last years to reduce the volume of the concentrate before disposal and with the objective of achieving zero liquid discharge and recovery of valuable compounds from these effluents are also reviewed. Most of these emerging technologies have been developed at laboratory or pilot plant scale (see Table 1). With regard to RO concentrates from WWTP, the manuscript addresses recent studies that are mainly focused on reducing the organic pollutant load through the application of innovative advanced oxidation technologies. Finally, works that report the treatment of RO concentrates from industrial sources are analyzed as well. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Sanitization of an Automatic Reverse-Osmosis Watering System: Removal of a Clinically Significant Biofilm

    Science.gov (United States)

    Molk, Denise M; Karr-May, Charlene L; Trang, Elaine D; Sanders, George E

    2013-01-01

    During environmental monitoring of our institution's rodent watering systems, one vivarium was found to have high bacterial loads in the reverse-osmosis (RO) automatic water system. These findings prompted evaluation of the entire RO water production and distribution system. Investigation revealed insufficient rack and RO system sanitization, leading to heavy biofilm accumulation within the system. Approximately 2 wk after discovery in the water system, one of the bacterial organisms isolated in the water supply, Sphingomonas paucimobilis, was isolated from a peritoneal abscess of a severely immunodeficient B6.Cg-Slc11a1r Rag1tm1Mom/Cwi mouse housed in the same vivarium, suggesting that rodents drinking from this system were being exposed randomly to fragments of biofilm. Plans were developed to sanitize the entire system. Hypercholorination was used first, followed by treatment with a combination of peracetic acid and hydrogen peroxide. Between system sanitizations, a low-level chlorine infusion was added to the system as a biocide. Heterotrophic plate counts and bacterial isolation were performed on water samples obtained before and after sanitization procedures. We here discuss the process of identifying and correcting this important water-quality issue. PMID:23562105

  2. Advanced Control Synthesis for Reverse Osmosis Water Desalination Processes.

    Science.gov (United States)

    Phuc, Bui Duc Hong; You, Sam-Sang; Choi, Hyeung-Six; Jeong, Seok-Kwon

    2017-11-01

      In this study, robust control synthesis has been applied to a reverse osmosis desalination plant whose product water flow and salinity are chosen as two controlled variables. The reverse osmosis process has been selected to study since it typically uses less energy than thermal distillation. The aim of the robust design is to overcome the limitation of classical controllers in dealing with large parametric uncertainties, external disturbances, sensor noises, and unmodeled process dynamics. The analyzed desalination process is modeled as a multi-input multi-output (MIMO) system with varying parameters. The control system is decoupled using a feed forward decoupling method to reduce the interactions between control channels. Both nominal and perturbed reverse osmosis systems have been analyzed using structured singular values for their stabilities and performances. Simulation results show that the system responses meet all the control requirements against various uncertainties. Finally the reduced order controller provides excellent robust performance, with achieving decoupling, disturbance attenuation, and noise rejection. It can help to reduce the membrane cleanings, increase the robustness against uncertainties, and lower the energy consumption for process monitoring.

  3. Removal of radionuclides in drinking water by membrane treatment using ultrafiltration, reverse osmosis and electrodialysis reversal.

    Science.gov (United States)

    Montaña, M; Camacho, A; Serrano, I; Devesa, R; Matia, L; Vallés, I

    2013-11-01

    A pilot plant had been built to test the behaviour of ultrafiltration (UF), reverse osmosis (RO), and electrodialysis reversal (EDR) in order to improve the quality of the water supplied to Barcelona metropolitan area from the Llobregat River. This paper presents results from two studies to reduce natural radioactivity. The results from the pilot plant with four different scenarios were used to design the full-scale treatment plant built (SJD WTP). The samples taken at different steps of the treatment were analysed to determine gross alpha, gross beta and uranium activity. The results obtained revealed a significant improvement in the radiological water quality provided by both membrane techniques (RO and EDR showed removal rates higher than 60%). However, UF did not show any significant removal capacity for gross alpha, gross beta or uranium activities. RO was better at reducing the radiological parameters studied and this treatment was selected and applied at the full scale treatment plant. The RO treatment used at the SJD WTP reduced the concentration of both gross alpha and gross beta activities and also produced water of high quality with an average removal of 95% for gross alpha activity and almost 93% for gross beta activity at the treatment plant. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Application of pressure assisted forward osmosis for water purification and reuse of reverse osmosis concentrate from a water reclamation plant

    KAUST Repository

    Jamil, Shazad

    2016-07-26

    The use of forward osmosis (FO) is growing among the researchers for water desalination and wastewater treatment due to use of natural osmotic pressure of draw solute. In this study pressure assisted forward osmosis (PAFO) was used instead of FO to increase the water production rate. In this study a low concentration of draw solution (0.25 M KCl) was applied so that diluted KCl after PAFO operation can directly be used for fertigation. The performance of PAFO was investigated for the treatment of reverse osmosis concentrate (ROC) from a water reclamation plant. The water production in PAFO was increased by 9% and 29% at applied pressure of 2 and 4 bars, respectively, to feed side based on 90 h of experiments. Granular activated carbon (GAC) pretreatment and HCl softening were used to reduce organic fouling and scaling prior to application of PAFO. It reduced total organic carbon (TOC) and total inorganic carbon (TIC) by around 90% and 85%, respectively from untreated ROC. Subsequently, this led to an increase in permeate flux. In addition, GAC pretreatment adsorbed 12 out of 14 organic micropollutants tested from ROC to below detection limit. This application enabled to minimise the ROC volume with a sustainable operation and produced high quality and safe water for discharge or reuse. The draw solution (0.25 M KCl) used in this study was diluted to 0.14 M KCl, which is a suitable concentration (10 kg/m3) for fertigation, due to water transport from feed solution. © 2016 Elsevier B.V.

  5. Particle count monitoring of reverse osmosis water treatment for removal of low-level radionuclides

    International Nuclear Information System (INIS)

    Moritz, E.J.; Hoffman, C.R.; Hergert, T.R.

    1995-01-01

    Laser diode particle counting technology and analytical measurements were used to evaluate a pilot-scale reverse osmosis (RO) water treatment system for removal of particulate matter and sub-picocurie low-level radionuclides. Stormwater mixed with Waste Water Treatment Plant (WWTP) effluent from the Rocky Flats Environmental Technology Site (RFETS), formerly a Department of Energy (DOE) nuclear weapons production facility, were treated. No chemical pretreatment of the water was utilized during this study. The treatment system was staged as follows: multimedia filtration, granular activated carbon adsorption, hollow tube ultrafiltration, and reverse osmosis membrane filtration. Various recovery rates and two RO membrane models were tested. Analytical measurements included total suspended solids (TSS), total dissolved solids (TDS), gross alpha (α) and gross beta (β) activity, uranium isotopes 233/234 U and 238 U, plutonium 239/240 Pu, and americium 241 Am. Particle measurement between 1--150 microns (μ) included differential particle counts (DPC), and total particle counts (TPC) before and after treatment at various sampling points throughout the test. Performance testing showed this treatment system produced a high quality effluent in clarity and purity. Compared to raw water levels, TSS was reduced to below detection of 5 milligrams per liter (mg/L) and TDS reduced by 98%. Gross α was essentially removed 100%, and gross β was reduced an average of 94%. Uranium activity was reduced by 99%. TPC between 1-150μ were reduced by an average 99.8% to less than 1,000 counts per milliliter (mL), similar in purity to a good drinking water treatment plant. Raw water levels of 239/240 Pu and 241 Am were below reliable quantitation limits and thus no removal efficiencies could be determined for these species

  6. Reverse osmosis using for water demineralization for supplying the NPP and TPP steam generators

    International Nuclear Information System (INIS)

    Mamet, A.P.; Sitnyakovskij, Yu.A.

    2000-01-01

    Paper analyzes the conditions affecting the efficiency of water reverse-osmosis demineralization for NPP and TPP steam generators and presents an example of efficient application of a membrane reverse-osmosis facility serving as the first stage of water demineralization at the Mosehnergo Joint-Stock Company heating and power plant no. 23 to feed boilers [ru

  7. Contaminants of emerging concern in reverse osmosis brine concentrate from indirect/direct water reuse applications.

    Science.gov (United States)

    Romeyn, Travis R; Harijanto, Wesley; Sandoval, Sofia; Delagah, Saied; Sharbatmaleki, Mohamadali

    2016-01-01

    Water shortage is becoming more common due to droughts and global population increases resulting in the increasing popularity of water reuse to create new water sources. Reverse osmosis (RO) membrane systems are popular in these applications since they can produce drinking water quality effluent. Unfortunately, RO systems have the drawback of generating concentrate streams that contain contaminants rejected by the membrane including chemicals of emerging concern (CECs). CECs are chemicals such as hormones, steroids, pesticides, pharmaceuticals, and personal care products that are used for their intended purpose and then released into wastewater. CECs are believed to be detrimental to aquatic wildlife health and pose an unknown human health risk. This research gathered the existing knowledge on CEC presence in concentrate, available proven concentrate treatment methods, their CEC removal abilities, and current CEC regulations. It was found that 127 CECs have been measured in RO concentrate with 100 being detected at least once. The most potent treatment process available is UV/H2O2 as it offers the highest removal rates for the widest range of chemicals. The less expensive process of ozone/biologically activated carbon offers slightly lower removal abilities. This comprehensive report will provide the groundwork for better understanding, regulating and treating concentrate stream CECs.

  8. Plutonium decontamination studies using Reverse Osmosis

    International Nuclear Information System (INIS)

    Plock, C.E.; Travis, T.N.

    1980-01-01

    Water in batches of 45 gallons each, from a creek crossing the Rocky Flats Plant, was transferred to the Reverse Osmosis (RO) laboratory for experimental testing. The testing involved using RO for plutonium decontamination. For each test, the water was spiked with plutonium, had its pH adjusted, and was then processed by RO. At a water recovery level of 87%, the plutonium decontamination factors ranged from near 100 to 1200, depending on the pH of the processed water

  9. Direct osmosis method of purification and desalination of drinking water

    International Nuclear Information System (INIS)

    Khaydarov, R.A.; Khaydarov, R.R.

    2005-01-01

    Full text: Drinking water quality is one of the general factors influencing people's health. The human activity in industry and agriculture has led to pollution of the environment: soil, air, both surface and ground waters that are polluted with chemical substances. It has a disastrous effect on the health of the population, especially of children. At present, the known equipment, based on ion exchange, electrodialysis and reverse osmosis, require great expense, energy expenditures, and highly qualified personnel that are inaccessible to the population especially living in remote regions. Methods, which are usually used in water supplying plants, cannot remove spore forms of bacteria and many types of chemical substances. The purpose of this Project is to create an absolutely new method for purification of drinking water from chemical and biological agents. The method is based on using direct osmosis process that removes all contaminants except one and removing last contaminant. This method will be used for making new low energy-consuming and cheap mini-systems for individual and collective use for desalination of drinking water and purification from bacteria, radionuclides, heavy metal ions, and organic contaminants. Preliminary experiments and calculations conducted in Uzbekistan show that the energy consumption is 0.8 MW per 1 m 3 of water. Advantage of the method is low energy consumption, potentially purifying water without pretreatment and removing different types of bacteria including spore forms, radionuclides, heavy metal ions, organic contaminants. Devices can be powered by solar units in remote locations. The purpose of this work is further elaboration of this technology creation of new method and its accommodation to conditions of different countries. Test models will be made and tested in laboratories of interested countries

  10. Rejection of pharmaceuticals in nanofiltration and reverse osmosis membrane drinking water treatment.

    Science.gov (United States)

    Radjenović, J; Petrović, M; Ventura, F; Barceló, D

    2008-08-01

    This paper investigates the removal of a broad range of pharmaceuticals during nanofiltration (NF) and reverse osmosis (RO) applied in a full-scale drinking water treatment plant (DWTP) using groundwater. Pharmaceutical residues detected in groundwater used as feed water in all five sampling campaigns were analgesics and anti-inflammatory drugs such as ketoprofen, diclofenac, acetaminophen and propyphenazone, beta-blockers sotalol and metoprolol, an antiepileptic drug carbamazepine, the antibiotic sulfamethoxazole, a lipid regulator gemfibrozil and a diuretic hydrochlorothiazide. The highest concentrations in groundwater were recorded for hydrochlorothiazide (58.6-2548ngL(-1)), ketoprofen (85%). Deteriorations in retentions on NF and RO membranes were observed for acetaminophen (44.8-73 %), gemfibrozil (50-70 %) and mefenamic acid (30-50%). Furthermore, since several pharmaceutical residues were detected in the brine stream of NF and RO processes at concentrations of several hundreds nanogram per litre, its disposal to a near-by river can represent a possible risk implication of this type of treatment.

  11. Reverse osmosis integrity monitoring in water reuse: The challenge to verify virus removal - A review.

    Science.gov (United States)

    Pype, Marie-Laure; Lawrence, Michael G; Keller, Jurg; Gernjak, Wolfgang

    2016-07-01

    A reverse osmosis (RO) process is often included in the treatment train to produce high quality reuse water from treated effluent for potable purposes because of its high removal efficiency for salinity and many inorganic and organic contaminants, and importantly, it also provides an excellent barrier for pathogens. In order to ensure the continued protection of public health from pathogen contamination, monitoring RO process integrity is necessary. Due to their small sizes, viruses are the most difficult class of pathogens to be removed in physical separation processes and therefore often considered the most challenging pathogen to monitor. To-date, there is a gap between the current log credit assigned to this process (determined by integrity testing approved by regulators) and its actual log removal capability as proven in a variety of laboratory and pilot studies. Hence, there is a challenge to establish a methodology that more closely links to the theoretical performance. In this review, after introducing the notion of risk management in water reuse, we provide an overview of existing and potentially new RO integrity monitoring techniques, highlight their strengths and drawbacks, and debate their applicability to full-scale treatment plants, which open to future research opportunities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Corrosion Inhibition of the Galvanic Couple Copper-Carbon Steel in Reverse Osmosis Water

    Directory of Open Access Journals (Sweden)

    Irene Carrillo

    2011-01-01

    Full Text Available The purpose of this paper is to evaluate the electrochemical behaviour of corrosion inhibition of the copper-carbon steel galvanic couple (Cu-CS, exposed to reverse osmosis water (RO used for rinsing of heat exchangers for heavy duty machinery, during manufacture. Molybdate and nitrite salts were utilized to evaluate the inhibition behaviour under galvanic couple conditions. Cu-CS couple was used as working electrodes to measure open circuit potential (OCP, potentiodynamic polarization (PP, and electrochemical impedance spectroscopy (EIS. The surface conditions were characterized by scanning electron microscopy (SEM and electron dispersive X-ray spectroscopy (EDS. The most effective concentration ratio between molybdate and nitrite corrosion inhibitors was determined. The morphological study indicated molybdate deposition on the anodic sites of the galvanic couple. The design of molybdate-based corrosion inhibitor developed in the present work should be applied to control galvanic corrosion of the Cu-CS couple during cleaning in the manufacture of heat exchangers.

  13. REMOVAL OF CHLORINATED ALKENE SOLVENTS FROM DRINKING WATER BY VARIOUS REVERSE OSMOSIS MEMBRANES

    Science.gov (United States)

    Historically, membranes have been used to desalinate water. As new membrane materials are developed, traditional water treatment schemes may incorporate membrane technologies, such as reverse osmosis, to address a variety of new concerns such as low molecular weight volatile org...

  14. REMOVAL OF CHLORINATED AND BROMINATED ALKANES FROM DRINKING WATER USING REVERSE OSMOSIS

    Science.gov (United States)

    Membrane use in water treatment has historically focused on desalination. With the development of new membrane materials, attention began to focus on reverse osmosis and pervaporation as alternatives to traditional water treatment processes. This paper addresses the use of reve...

  15. Diagnosis of small capacity reverse osmosis desalination unit for domestic water

    International Nuclear Information System (INIS)

    Hillali, Z.; Hamed, A.; Elfil, Hamza; Ferjani, E.

    2009-01-01

    Tunisian norm of drinking water tolerates a maximum TDS of 1.5 g/L, and the domestic water presents usually a salinity grater than 500 mg/L. In the last years, several small capacity reverse osmosis desalination prototypes have been marketed. They are used to desalinate brackish water with TDS lower than 1.5 g/L. This RO unit, tested with tap waters during four years, was diagnosed. The RO unit produces 10-15 L/Hour with a recovery rate between 25 and 40 pour cent and salt rejection in order of 90 pour cent. The salinity of the tested domestic water is located between 0.4 and 1.4 g/L. Water pretreatment is composed of three filtration operations (cartridge filter, granulate active carbon filter and 5 =m cartridge filter). Pretreated water is pumped through RO membrane with maximum pressure of 6 bars. At the 4th year, the RO unit performances were substantial decreased. Recovery rate and salt rejection fall down more than 50 and 100% respectively and the pressure drop increase from 1 to 2.1 bar The membrane regeneration allowed only the rate recovery restoration. The membrane selectivity was not improved. The membrane seems irreversibly damaged by the tap water chlorine none retained by the deficient pretreatment. An autopsy of the used RO membrane was done by different analysis techniques as SEM/EDX, AFM, XRD and FTIR spectroscopy. The analysis of membrane (proper and used) surfaces show a deposit film on the used membrane witch evaluated to environ 2 =m, it indicates a fooling phenomenon. The SEM photos show deterioration on the active layer material of the membrane witch seems attacked by the tap water chlorine. The X Rays Diffraction and FTIR show that the deposit collected on the used membrane contains organic and mineral (Gypsum, SiO 2 and clays) materials. Silicates and clays can exist in tap waters and reach the RO membrane when the pretreatment micro-filter became deficient. The Gypsum presence is due only to germination on the membrane.

  16. Reverse osmosis based water treatment and purification systems for nuclear power installations

    International Nuclear Information System (INIS)

    Epimakhov, V.N.; Olejnik, M.S.; Moskvin, L.N.

    2004-01-01

    Experiments on the realization and service of specialized water treatment and purification plants based on the principle of reverse osmosis filtration of water at the NPU benches of the A.P. Aleksandrov Scientific Research Technological Institute (SRTI) are analyzed. Membrane-sorption unit including module of micro-, ultrafiltration, reverse osmosis and ion exchange with productivity to 0.5 m 3 /h is developed and operated at SRTI. It is demonstrated that reverse osmosis purification of manufacturing water significantly improves service conditions of NPU and decreases salinity [ru

  17. Obtaining water with a high degree of purity by using reverse osmosis

    Directory of Open Access Journals (Sweden)

    Nicolae Chirilă

    2011-12-01

    Full Text Available In this paper, we used the method of reverse osmosis in order to obtain water with a high degree of purity. For this aim, we used the TKA 20-120ECO device. We completed physic-chemical determinations for the water of supply, as well as for the water obtained after the osmosis process. The results that we obtained are relevant and interesting.

  18. A comparison of surface water natural organic matter in raw filtered water samples, XAD, and reverse osmosis isolates

    Science.gov (United States)

    Maurice, P.A.; Pullin, M.J.; Cabaniss, S.E.; Zhou, Q.; Namjesnik-Dejanovic, K.; Aiken, G.R.

    2002-01-01

    This research compared raw filtered waters (RFWs), XAD resin isolates (XAD-8 and XAD-4), and reverse osmosis (RO) isolates of several surface water samples from McDonalds Branch, a small freshwater fen in the New Jersey Pine Barrens (USA). RO and XAD-8 are two of the most common techniques used to isolate natural organic matter (NOM) for studies of composition and reactivity; therefore, it is important to understand how the isolates differ from bulk (unisolated) samples and from one another. Although, any comparison between the isolation methods needs to consider that XAD-8 is specifically designed to isolate the humic fraction, whereas RO concentrates a broad range of organic matter and is not specific to humics. The comparison included for all samples: weight average molecular weight (Mw), number average molecular weight (Mn), polydispersity (??), absorbance at 280nm normalized to moles C (??280) (RFW and isolates); and for isolates only: elemental analysis, % carbon distribution by 13C NMR, and aqueous FTIR spectra. As expected, RO isolation gave higher yield of NOM than XAD-8, but also higher ash content, especially Si and S. Mw decreased in the order: RO>XAD-8>RFW>XAD-4. The Mw differences of isolates compared with RFW may be due to selective isolation (fractionation), or possibly in the case of RO to condensation or coagulation during isolation. 13C NMR results were roughly similar for the two methods, but the XAD-8 isolate was slightly higher in 'aromatic' C and the RO isolate was slightly higher in heteroaliphatic and carbonyl C. Infrared spectra indicated a higher carboxyl content for the XAD-8 isolates and a higher ester:carboxyl ratio for the RO isolates. The spectroscopic data thus are consistent with selective isolation of more hydrophobic compounds by XAD-8, and also with potential ester hydrolysis during that process, although further study is needed to determine whether ester hydrolysis does indeed occur. Researchers choosing between XAD and RO

  19. Forward osmosis for the treatment of reverse osmosis concentrate from water reclamation: process performance and fouling control.

    Science.gov (United States)

    Kazner, C; Jamil, S; Phuntsho, S; Shon, H K; Wintgens, T; Vigneswaran, S

    2014-01-01

    While high quality water reuse based on dual membrane filtration (membrane filtration or ultrafiltration, followed by reverse osmosis) is expected to be progressively applied, treatment and sustainable management of the produced reverse osmosis concentrate (ROC) are still important issues. Forward osmosis (FO) is a promising technology for maximising water recovery and further dewatering ROC so that zero liquid discharge is produced. Elevated concentrations of organic and inorganic compounds may act as potential foulants of the concentrate desalting system, in that they consist of, for example, FO and a subsequent crystallizer. The present study investigated conditions under which the FO system can serve as concentration phase with the focus on its fouling propensity using model foulants and real ROC. Bulk organics from ROC consisted mainly of humic acids (HA) and building blocks since wastewater-derived biopolymers were retained by membrane filtration or ultrafiltration. Organic fouling of the FO system by ROC-derived bulk organics was low. HA was only adsorbed moderately at about 7% of the initial concentration, causing a minor flux decline of about 2-4%. However, scaling was a major impediment to this process if not properly controlled, for instance by pH adjustment or softening.

  20. RECYCLING NICKEL ELECTROPLATING RINSE WATERS BY LOW TEMPERATURE EVAPORATION AND REVERSE OSMOSIS

    Science.gov (United States)

    Low temperature evaporation and reverse osmosis systems were each evaluated (on a pilot scale) on their respective ability to process rinse water collected from a nickel electroplating operation. Each system offered advantages under specific operating conditions. The low temperat...

  1. Application of monochloramine for wastewater reuse: Effect on biostability during transport and biofouling in RO membranes

    KAUST Repository

    Siddiqui, Amber; Loubineaud, E.; Prest, E.I.E.C.; El Chakhtoura, Joline; Salles, C.; Bucs, Szilard; Trampé , J.; Van den Broek, W.B.P.; Van Agtmaal, J.M.C.; Van Loosdrecht, M.C.M.; Kruithof, J.C.; Vrouwenvelder, Johannes S.

    2018-01-01

    The rising demand for clean and safe water has increased the interest in advanced wastewater treatment and reuse. Reverse osmosis (RO) can provide reliable and high-quality water from treated wastewater. Biofouling inevitably occurs, certainly

  2. Using reverse osmosis to remove natural organic matter from power plant makeup water

    International Nuclear Information System (INIS)

    Mattaraj, S.; Kilduff, J.E.

    2003-01-01

    A field-scale reverse osmosis (RO) system was used to remove salts and natural organic matter (NOM) from a surface water source. The RO membrane exhibited an NOM solution hydraulic permeability of 8.33 x 10 -9 m x s -1 x kPa -1 , about 6% less than the clean water value, over pressures ranging from 414 to 1 000 kPa (60 to 145 psi). The rejection of salt and NOM were greater than 98% and 99%, respectively. Under controlled laboratory conditions, greater than 99% mass recovery of NOM could be obtained. A small fraction of NOM was not recovered using hydrodynamic cleaning but could be recovered with chemical cleaning (NaOH wash solution). The mass recovered in the NaOH solution increased from 6% with increasing transmembrane pressures from 414 kPa to 1 000 kPa, respectively. This is consistent with fouling that results from an increase in solution flux, and a concomitant decrease in tangential crossflow velocity. (orig.)

  3. Theory of Ion and Water Transport in Reverse-Osmosis Membranes

    Science.gov (United States)

    Oren, Y. S.; Biesheuvel, P. M.

    2018-02-01

    We present a theory for ion and water transport through reverse-osmosis (RO) membranes based on a Maxwell-Stefan framework combined with hydrodynamic theory for the reduced motion of particles in thin pores. We take into account all driving forces and frictions both on the fluid (water) and on the ions including ion-fluid friction and ion-wall friction. By including the acid-base characteristic of the carbonic acid system, the boric acid system, H3O+/OH- , and the membrane charge, we locally determine p H , the effective charge of the membrane, and the dissociation degree of carbonic acid and boric acid. We present calculation results for an experiment with fixed feed concentration, where effluent composition is a self-consistent function of fluxes through the membrane. A comparison with experimental results from literature for fluid flow vs pressure, and for salt and boron rejection, shows that our theory agrees very well with the available data. Our model is based on realistic assumptions for the effective size of the ions and makes use of a typical pore size of a commercial RO membrane.

  4. Removal of fouling species from brackish water reverse osmosis reject stream.

    Science.gov (United States)

    Ayoub, G M; Korban, L; Al-Hindi, M; Zayyat, R

    2018-03-01

    Brine disposal from reverse osmosis (RO) systems remains a major challenge for the desalination industry especially in inland areas where discharge options are very limited. Solutions will entail the introduction of economic treatment processes that will alleviate the brine's negative impact on the environment and reduce its discharge volume. Such processes could act as an intermediary treatment process for the recycling of the brine through an additional RO stage which, for brackish water (BW) desalination, could lead to saving valuable water while reducing the amount of brine discharge. In this context, the study at hand attempts to evaluate the effectiveness of a one-step chemical process for the treatment of BWRO brine. This study seeks to determine optimal operating conditions relative to type, ratio, and dosage of alkalizing chemicals, pH and temperature, for substantially reducing the concentrations of scaling parameters such as calcium, magnesium, silica, and strontium. The results indicate that precipitation softening at pH = 11.5 using combined chemical dosages of NaOH and Na 2 CO 3 in a ratio of 2:1 leads to substantial removal of calcium and magnesium (>95%) and moderately high removal of strontium and silica (>71%).

  5. Using microbial desalination cells to reduce water salinity prior to reverse osmosis

    KAUST Repository

    Mehanna, Maha

    2010-01-01

    A microbial desalination cell (MDC) is a new method to reduce the salinity of one solution while generating electrical power from organic matter and bacteria in another (anode) solution. Substantial reductions in the salinity can require much larger volumes of the anode solution than the saline water, but any reduction of salinity will benefit the energy efficiency of a downstream reverse osmosis (RO) desalination system. We investigated here the use of an MDC as an RO pre-treatment method using a new type of air-cathode MDC containing three equally sized chambers. A single cycle of operation using a 1 g L -1 acetate solution reduced the conductivity of salt water (5 g L-1 NaCl) by 43 ± 6%, and produced a maximum power density of 480 mW m-2 with a coulombic efficiency of 68 ± 11%. A higher concentration of acetate (2 g L-1) reduced solution conductivity by 60 ± 7%, and a higher salt concentration (20 g L-1 NaCl) reduced solution conductivity by 50 ± 7%. The use of membranes with increased ion exchange capacities further decreased the solution conductivity by 63 ± 2% (20 g L-1 NaCl). These results demonstrate substantial (43-67%) desalination of water is possible using equal volumes of anode solution and salt water. These results show that MDC treatment could be used to substantially reduce salt concentrations and thus energy demands for downstream RO processing, while at the same time producing electrical power. © 2010 The Royal Society of Chemistry.

  6. A Well Water Reverse Osmosis Desalination Unit Diagnosis

    International Nuclear Information System (INIS)

    Elfil, H.; Hila, M.; Hannachi, A.; Yeza, A.

    2009-01-01

    In this present work the diagnosis results of a reverse osmosis desalination unit are reported. Since 1997, the desalination unit was supplying a 1200 bed hotel. The feed water was driven from a well situated 300 m away form the sea. The water has an approximate salinity of 6gg.L -1 . The unit was producing 600 m 3 per day of desalinated water with a Total Dissolved Salts (TDS) of nearly 400 mg.L -1 . The desalination unit has two stages with 67 pour cent and 42 pour cent yields respectively giving an average yield of 81 pour cent. The behavior of all water streams with respect to aggressiveness and scaling tendency was assessed. The 2nd stage reject water was shown to exhibit a very high scaling behavior with an instantaneous precipitation in the absence of feed water chemical treatment. The analyses have shown that the produced water was very aggressive. The second stage module autopsy has revealed a sharp decrease of the membrane performances because of mineral as well as organic fooling buildup. The inorganic scale was essentially made of coesite and calcite and kaolinite clay. The presence of silica and clay could be attributed to an inadequate filtration pre-treatment process that was not able to retain all the suspended matter in the feed water. Whereas the presence calcite crystals at the membrane surface, reveals that the chemical inhibition performed at the pre-treatment process without adjusting the water pH was not able to prevent calcium carbonate precipitation. A periodic acid wash of the 2nd stage membranes is then necessary to guarantee this stage desired objectives.

  7. Reverse osmosis for wash water recovery in space vehicles.

    Science.gov (United States)

    Lawrence, R. W.; Saltonstall, C. W., Jr.

    1973-01-01

    Tests were carried out on both synthetic and real wash water derived from clothes laundry to determine the utility of reverse osmosis in recovering the water for recycle use. A blend membrane made from cellulose di- and triacetates, and a cross-linked cellulose acetate/methacrylate were evaluated. Both were found acceptable. A number of detergents were evaluated, including a cationic detergent, sodium dodecyl sulfate, potassium palmitate, and sodium dodecylbenzenesulfonate. The tests were all made at a temperature of 165 F to minimize microbial growth. Long-term (15 to 30 day) runs were made at 600 and 400 psi on laundry water which was pretreated either by alum addition and sand filtration or by filtration only through 0.5 micron filters. A 30-day run was made using a 2-in. diameter by 22-in. long spiral module at 400 psig with filtering as the pretreatment. The membrane fouling by colloidal matter was found to be controllable. The unit produced initially 55 gal/day and 27 gal/day after 30 days.

  8. MODIFIED REVERSE OSMOSIS SYSTEM FOR TREATMENT OF PRODUCED WATERS

    Energy Technology Data Exchange (ETDEWEB)

    T.M. Whitworth; Liangxiong Li

    2002-09-15

    This report describes work performed during the second year of the project ''Modified reverse osmosis system for treatment of produced waters.'' We performed two series of reverse osmosis experiments using very thin bentonite clay membranes compacted to differing degrees. The first series of 10 experiments used NaCl solutions with membranes that ranged between 0.041 and 0.064mm in thickness. Our results showed compaction of such ultra-thin clay membranes to be problematic. The thickness of the membranes was exceeded by the dimensional variation in the machined experimental cell and this is believed to have resulted in local bypassing of the membrane with a resultant decrease in solute rejection efficiency. In two of the experiments, permeate flow was varied as a percentage of the total flow to investigate results of changing permeate flow on solute rejection. In one experiment, the permeate flow was varied between 2.4 and 10.3% of the total flow with no change in solute rejection. In another experiment, the permeate flow was varied between 24.6 and 52.5% of the total flow. In this experiment, the solute rejection rate decreased as the permeate occupied greater fractions of the total flow. This suggests a maximum solute rejection efficiency for these clay membranes for a permeate flow of between 10.3 and 24.6% of the total; flow. Solute rejection was found to decrease with increasing salt concentration and ranged between 62.9% and 19.7% for chloride and between 61.5 and 16.8% for sodium. Due to problems with the compaction procedure and potential membrane bypassing, these rejection rates are probably not the upper limit for NaCl rejection by bentonite membranes. The second series of four reverse osmosis experiments was conducted with a 0.057mm-thick bentonite membrane and dilutions of a produced water sample with an original TDS of 196,250 mg/l obtained from a facility near Loco Hill, New Mexico, operated by an independent. These experiments

  9. MODIFIED REVERSE OSMOSIS SYSTEM FOR TREATMENT OF PRODUCED WATERS

    Energy Technology Data Exchange (ETDEWEB)

    T.M. Whitworth; Liangxiong Li

    2002-09-15

    This report describes work performed during the first year of the project ''Modified Reverse Osmosis System for Treatment of Produced Waters.'' This research project has two objectives. The first objective is to test the use of clay membranes in the treatment of produced waters by reverse osmosis. The second objective is to test the ability of a system patented by the New Mexico Tech Research Foundation to remove salts from reverse osmosis waste streams as a solid. We performed 12 experiments using clay membranes in cross-flow experimental cells. We found that, due to dispersion in the porous frit used adjacent to the membrane, the concentration polarization layer seems to be completely (or nearly completely) destroyed at low flow rates. This observation suggests that clay membranes used with porous frit material many reach optimum rejection rates at lower pumping rates than required for use with synthetic membranes. The solute rejection efficiency decreases with increasing solution concentration. For the membranes and experiments reported here, the rejection efficiency ranged from 71% with 0.01 M NaCl solution down to 12% with 2.3 M NaCl solution. More compacted clay membranes will have higher rejection capabilities. The clay membranes used in our experiments were relatively thick (approximately 0.5 mm). The active layer of most synthetic membranes is only 0.04 {micro}m (0.00004 mm), approximately 1250 times thinner than the clay membranes used in these experiments. Yet clay membranes as thin as 12 {micro}m have been constructed (Fritz and Eady, 1985). Since Darcy's law states that the flow through a material of constant permeability is inversely proportional to it's the material's thickness, then, based on these experimental observations, a very thin clay membrane would be expected to have much higher flow rates than the ones used in these experiments. Future experiments will focus on testing very thin clay membranes. The

  10. Electro-oxidation of reverse osmosis concentrates generated in tertiary water treatment.

    Science.gov (United States)

    Pérez, G; Fernández-Alba, A R; Urtiaga, A M; Ortiz, I

    2010-05-01

    This work investigates the application of the electro-oxidation technology provided with boron doped diamond (BDD), an electrode material which has shown outstanding properties in oxidation of organic and inorganic compounds, for the treatment of reverse osmosis (RO) concentrates generated in tertiary wastewater treatment plants (WWTP). Chemical oxygen demand (COD), ammonium and several anions were measured during the electro-oxidation process, and the influence of the applied current density (20-200A/m(2)) was analysed on process kinetics. Analytical assessment showed that several emerging pollutants (pharmaceuticals, personal care products, stimulants, etc.) were presented both in the effluent of the secondary WWTP as well as in the RO concentrate. For this reason, a group of 10 emerging pollutants, those found with higher concentrations, was selected in order to test whether electro-oxidation can be also applied for their mitigation. In the removal of emerging pollutants the electrical current density in the range 20-100A/m(2) did not show influence likely due to the mass transfer resistance developed in the process when the oxidized solutes are present in such low concentrations. Their removal rates were fitted to first order expressions, and the apparent kinetic constants for the anodic oxidation of each compound were calculated. Finally, the formation of trihalomethanes (THMs) has been checked; concluding that after selecting the appropriate operational conditions the attained concentration is lower than the standards for drinking water established in European and EPA regulations. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  11. Selective removal of arsenic and monovalent ions from brackish water reverse osmosis concentrate.

    Science.gov (United States)

    Xu, Pei; Capito, Marissa; Cath, Tzahi Y

    2013-09-15

    Concentrate disposal and management is a considerable challenge for the implementation of desalination technologies, especially for inland applications where concentrate disposal options are limited. This study has focused on selective removal of arsenic and monovalent ions from brackish groundwater reverse osmosis (RO) concentrate for beneficial use and safe environmental disposal using in situ and pre-formed hydrous ferric oxides/hydroxides adsorption, and electrodialysis (ED) with monovalent permselective membranes. Coagulation with ferric salts is highly efficient at removing arsenic from RO concentrate to meet a drinking water standard of 10 μg/L. The chemical demand for ferric chloride however is much lower than ferric sulfate as coagulant. An alternative method using ferric sludge from surface water treatment plant is demonstrated as an efficient adsorbent to remove arsenic from RO concentrate, providing a promising low cost, "waste treat waste" approach. The monovalent permselective anion exchange membranes exhibit high selectivity in removing monovalent anions over di- and multi-valent anions. The transport of sulfate and phosphate through the anion exchange membranes was negligible over a broad range of electrical current density. However, the transport of divalent cations such as calcium and magnesium increases through monovalent permselective cation exchange membranes with increasing current density. Higher overall salt concentration reduction is achieved around limiting current density while higher normalized salt removal rate in terms of mass of salt per membrane area and applied energy is attained at lower current density because the energy unitization efficiency decreases at higher current density. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Disinfection byproduct formation in reverse-osmosis concentrated and lyophilized natural organic matter from a drinking water source.

    Science.gov (United States)

    Pressman, Jonathan G; McCurry, Daniel L; Parvez, Shahid; Rice, Glenn E; Teuschler, Linda K; Miltner, Richard J; Speth, Thomas F

    2012-10-15

    Drinking water treatment and disinfection byproduct (DBP) research can be complicated by natural organic matter (NOM) temporal variability. NOM preservation by lyophilization (freeze-drying) has been long practiced to address this issue; however, its applicability for drinking water research has been limited because the selected NOM sources are atypical of most drinking water sources. The purpose of this research was to demonstrate that reconstituted NOM from a lyophilized reverse-osmosis (RO) concentrate of a typical drinking water source closely represents DBP formation in the original NOM. A preliminary experiment assessed DBP formation kinetics and yields in concentrated NOM, which demonstrated that chlorine decays faster in concentrate, in some cases leading to altered DBP speciation. Potential changes in NOM reactivity caused by lyophilization were evaluated by chlorination of lyophilized and reconstituted NOM, its parent RO concentrate, and the source water. Bromide lost during RO concentration was replaced by adding potassium bromide prior to chlorination. Although total measured DBP formation tended to decrease slightly and unidentified halogenated organic formation tended to increase slightly as a result of RO concentration, the changes associated with lyophilization were minor. In lyophilized NOM reconstituted back to source water TOC levels and then chlorinated, the concentrations of 19 of 21 measured DBPs, constituting 96% of the total identified DBP mass, were statistically indistinguishable from those in the chlorinated source water. Furthermore, the concentrations of 16 of 21 DBPs in lyophilized NOM reconstituted back to the RO concentrate TOC levels, constituting 86% DBP mass, were statistically indistinguishable from those in the RO concentrate. This study suggests that lyophilization can be used to preserve concentrated NOM without substantially altering the precursors to DBP formation. Published by Elsevier Ltd.

  13. Oilfield water treatment by electrocoagulation-reverse osmosis for agricultural use: effects on germination and early growth characteristics of sunflower.

    Science.gov (United States)

    de Souza, Paulo S A; Cerqueira, Alexandre A; Rigo, Michelle M; de Paiva, Julieta L; Couto, Rafael S P; Merçon, Fábio; Perez, Daniel V; Marques, Monica R C

    2017-05-01

    This study aims to evaluate the effects of oilfield water (OW), treated by a hybrid process of electrocoagulation and reverse osmosis (EC-RO), on seed germination and early growth characteristics of sunflower (Heliantus annus L.). In the EC step, tests were conducted with 28.6 A m -2 current density and 4 min. reaction time. In the RO step, the system was operated with 1 L min -1 constant flow and 2 MPa, 2.5 MPa and 3 MPa feed pressures. In all feed pressures, RO polymeric membranes achieved very high removals of chemical oxygen demand (up to 89%) and oils and greases (100%) from EC-treated effluent. In best feed pressure (2.5 MPa), turbidity, total dissolved salts, electrical conductivity, salinity, toxic ions and sodium adsorption ratio values attained internationally recognized standards for irrigation water. Using EC-RO (feed pressure:2.5 MPa) treated OW, germinated sunflower seeds percentage (86 ± 6%), speed of germination (30 ± 2) and biomass production (49 ± 5 mg) were statistically similar to control (distilled water) results. Vigor index average values obtained using OW treated by EC-RO (3871)were higher than that obtained by OW water treated by EC (3300). The results of this study indicate that EC-RO seems to be a promising alternative for treatment of OW aiming sunflower crops irrigation, since the use of this treated effluent did not affect adversely seed germination and seedling development, and improved seedling vigor. Furthermore, OW treatment by EC-RO reduces sodium levels into acceptable standards values avoiding soil degradation.

  14. Reverse osmosis application studies

    International Nuclear Information System (INIS)

    Golomb, A.

    1982-02-01

    To assess the feasibility of applying reverse osmosis (RO) and ultrafiltration (UF) for effective treatment of process and waste streams from operations at Ontario Hydro's thermal and nuclear stations, an extensive literature survey has been carried out. It is concluded that RO is not at present economic for pretreatment of Great Lakes water prior to ion exchange demineralization for boiler makeup. Using both conventional and novel commercial membrane modules, RO pilot studies are recommended for treatment of boiler cleaning wastes, fly ash leachates, and flue gas desulphurization scrubber discharges for removal of heavy metals. Volume reduction and decontamination of nuclear station low-level active liquid waste streams by RO/UF also appear promising. Research programmes are proposed

  15. A floating cogeneration system using the Russian KLT-40 reactor and Canadian reverse osmosis water purification technology

    International Nuclear Information System (INIS)

    Humphries, J.R.; Davies, K.

    1997-01-01

    As the global consumption of water increases with growing populations and rising levels of industrialization, major new sources of potable water production must be developed. To address this issue efficiently and economically, a new approach has been developed in Canada for the integration of reverse osmosis (RO) desalination systems with nuclear reactors as an energy source. The use of waste heat from the electrical generation process to preheat the RO feedwater, advanced feedwater pre-treatment and sophisticated system design integration and optimization techniques have led to improved water production efficiency, lower water production costs and reduced environmental impacts. CANDESAL Inc., has studied the use of its approach to the application of RO technology in the Russian APWS-80 floating nuclear desalination plant. Case studies show that water production efficiently improvements up to about 16% can be achieved. The energy consumed for the CANDESAL optimized APWS-80 design configuration is 4.2 kW·h/m 3 compared to the base APWS-80 design value of 4.9 kW·h/m 3 . Although only a preliminary study, these results suggest that significant improvements in the cost of water production can be achieved. The potential benefits warrant further detailed evaluation followed by a demonstration project. (author). 1 ref., 6 figs, 2 tabs

  16. Highly water soluble nanoparticles as a draw solute in forward osmosis for the treatment of radioactive liquid waste

    International Nuclear Information System (INIS)

    Yang, Heeman; Choi, Hye Min; Jang, Sungchan; Seo, Bumkyoung; Lee, Kune Woo; Moon, Jei Kwon

    2014-01-01

    . In this study, we introduced highly water-soluble hyperbranched caroboxylated polyglycerol-coated magnetic nanoparticles (CPG-MNPs). It is known that the highly branched, globular architecture of PG significantly increase solubility compared to linear polymer and they are eco-friendly. The CPG-MNPs showed no aggregate of particles in water even after placing external magnet, and exhibited a high water flux in FO process. The CPG-MNPs are, therefore, potentially useful as a draw solute in FO processes. The operation of nuclear pressurized water reactors (PWRs) results in numerous radioactive waste streams which vary in radioactivity content. Most PWR stations have experienced leakages of boric acid into liquid radioactive waste systems. These wastes contain about 0.3∼0.8 wt% of boric acid. It is known that reverse osmosis (RO) membrane can eliminate boron at high pH and boron of 40∼90% can be removed by RO membrane in pH condition. RO uses hydraulic pressure to oppose, and exceed, the osmotic pressure of an aqueous feed solution containing boric acid. Forward osmosis (FO), a low energy technique based on membrane technologies, has recently garnered attention for its utility in wastewater treatment and desalination applications. In the FO process, water flows across a semi-permeable membrane from a solution with a low osmotic pressure (the feed solution) to a solution with a high osmotic pressure (the draw solution). The driving force in FO processes is provided by the osmotic gradient between the two solutions. Low energy costs and low degrees of membrane fouling are two of the advantages conveyed by FO processes over other processes, such as reverse osmosis processes that rely on a hydraulic pressure driving force. However, the challenges of FO still lie in the fabrication of eligible FO membranes and the readily separable draw solutes of high osmotic pressures. Superparamagnetic Fe3O4 nanoparticles can be separated from water by an external magnet field

  17. Highly water soluble nanoparticles as a draw solute in forward osmosis for the treatment of radioactive liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Heeman; Choi, Hye Min; Jang, Sungchan; Seo, Bumkyoung; Lee, Kune Woo; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    . In this study, we introduced highly water-soluble hyperbranched caroboxylated polyglycerol-coated magnetic nanoparticles (CPG-MNPs). It is known that the highly branched, globular architecture of PG significantly increase solubility compared to linear polymer and they are eco-friendly. The CPG-MNPs showed no aggregate of particles in water even after placing external magnet, and exhibited a high water flux in FO process. The CPG-MNPs are, therefore, potentially useful as a draw solute in FO processes. The operation of nuclear pressurized water reactors (PWRs) results in numerous radioactive waste streams which vary in radioactivity content. Most PWR stations have experienced leakages of boric acid into liquid radioactive waste systems. These wastes contain about 0.3∼0.8 wt% of boric acid. It is known that reverse osmosis (RO) membrane can eliminate boron at high pH and boron of 40∼90% can be removed by RO membrane in pH condition. RO uses hydraulic pressure to oppose, and exceed, the osmotic pressure of an aqueous feed solution containing boric acid. Forward osmosis (FO), a low energy technique based on membrane technologies, has recently garnered attention for its utility in wastewater treatment and desalination applications. In the FO process, water flows across a semi-permeable membrane from a solution with a low osmotic pressure (the feed solution) to a solution with a high osmotic pressure (the draw solution). The driving force in FO processes is provided by the osmotic gradient between the two solutions. Low energy costs and low degrees of membrane fouling are two of the advantages conveyed by FO processes over other processes, such as reverse osmosis processes that rely on a hydraulic pressure driving force. However, the challenges of FO still lie in the fabrication of eligible FO membranes and the readily separable draw solutes of high osmotic pressures. Superparamagnetic Fe3O4 nanoparticles can be separated from water by an external magnet field

  18. Domestic wash water reclamation for reuse as commode water supply using filtration: Reverse-osmosis separation technique

    Science.gov (United States)

    Hall, J. B., Jr.; Batten, C. E.; Wilkins, J. R.

    1974-01-01

    A combined filtration-reverse-osmosis water recovery system has been evaluated to determine its capability to reclaim domestic wash water for reuse as a commode water supply. The system produced water that met all chemical and physical requirements established by the U.S. Public Health Service for drinking water with the exception of carbon chloroform extractables, methylene blue active substances, and phenols. It is thought that this water is of sufficient quality to be reused as commode supply water. The feasibility of using a combined filtration and reverse-osmosis technique for reclaiming domestic wash water has been established. The use of such a technique for wash-water recovery will require a maintenance filter to remove solid materials including those less than 1 micron in size from the wash water. The reverse-osmosis module, if sufficiently protected from plugging, is an attractive low-energy technique for removing contaminants from domestic wash water.

  19. Association of Vitamin B12 Deficiency and Use of Reverse Osmosis Processed Water for Drinking: A Cross-Sectional Study from Western India.

    Science.gov (United States)

    Gupta, Ekant Surendra; Sheth, Sanket Pranjivan; Ganjiwale, Jaishree Deepak

    2016-05-01

    Prevalence of Vitamin B12 deficiency has increased in community in recent time. Possibility is raised for new and yet unidentified factors being associated with this increased prevalence. One of these factors frequently questioned is use of Reverse Osmosis (RO) processed water for drinking. We aimed to study association of use of RO processed water for drinking with Vitamin B12 deficiency. This cross-sectional study was done at tertiary care centre of Western India. Total 250 participants were recruited after excluding those participants with known factors responsible for Vitamin B12 deficiency. Information about gender, type of diet, milk intake and duration, dairy product intake, use of RO water and Vitamin B12 level was collected. Total 70 (28%) participants out of 250 were having Vitamin B12 deficiency. Forty (50.6%) of 79 participants using RO water were Vitamin B12 deficient against 30 (17.5%) of 171 using other sources. Logistic regression analysis showed independent association between use of RO water and Vitamin B12 deficiency. Although association of male gender, milk quantity of less than 100 ml per day and duration of RO water intake with occurrence of Vitamin B12 deficiency was found statistically significant in univariate analysis, logistic regression analysis did not show significant association. Use of RO processed drinking water was associated with Vitamin B12 deficiency. This being cross- sectional study, further longitudinal studies with large sample size and taking confounding factors into consideration, are required to establish this association.

  20. Progress in the development of the reverse osmosis process for spacecraft wash water recovery.

    Science.gov (United States)

    Pecoraro, J. N.; Podall, H. E.; Spurlock, J. M.

    1972-01-01

    Research work on ambient- and pasteurization-temperature reverse osmosis processes for wash water recovery in a spacecraft environment is reviewed, and the advantages and drawbacks of each are noted. A key requirement in each case is to provide a membrane of appropriate stability and semipermeability. Reverse osmosis systems intended for such use must also take into account the specific limitations and requirements imposed by the small volume of water to be processed and the high water recovery desired. The incorporation of advanced high-temperature membranes into specially designed modules is discussed.

  1. Removal of heavy-metal pollutants from ground water using a reverse-osmosis/coupled-transport hybrid system

    International Nuclear Information System (INIS)

    Edlund, D.J.; Friesen, D.T.; Ray, R.J.; Scholfield, R.W.

    1993-01-01

    Two membrane processes - reverse osmosis (RO) and coupled transport (CT) - are useful in removing heavy metals from aqueous solutions and producing purified water. Each process has advantages. RO produces clean water reliably and relatively inexpensively. However, the pollutants are removed nonselectively and cannot be appreciably concentrated. CT removes pollutants selectively and can concentrate them by several orders of magnitude, but CT suffers from limited reliability and performs poorly at low pollutant concentrations. By combining these two unit processes in a hybrid process, it is possible to capitalize on the advantages of each process and to minimize their disadvantages. The RO/CT hybrid process the authors are developing removes more than 98% of the uranium and chromium in a contaminated groundwater stream - reducing concentrations of each pollutant to less than 100 ppb. These pollutants are simultaneously recovered as a concentrate at metal-ion concentrations greater than 1 wt% in relatively pure form. The hybrid process promises to be reliable and to reduce treatment costs below that for costs if either CT or RO were used alone. Even more importantly, the high selectivity of the hybrid process minimizes the volume of waste requiring disposal

  2. The Use of Reverse Osmosis for the Removal of As(III) and As(V) in Drinking Water

    OpenAIRE

    Garcia Ortiz, Christian Adriana

    2012-01-01

    The following thesis project was designed to collect data on the use of reverse osmosis for arsenic removal in drinking water and to explore economic methods for sample analysis with emphasis on the use of an ion exchange resin for arsenic speciation. The data collected was meant for verification of existing results, finding an optimal operating point for the reverse osmosis unit provided by Malthe Winje DWS, and to determine whether double filtration by reverse osmosis increases the removal ...

  3. Hexavalent Chromium Removal from Model Water and Car Shock Absorber Factory Effluent by Nanofiltration and Reverse Osmosis Membrane

    Directory of Open Access Journals (Sweden)

    Amine Mnif

    2017-01-01

    Full Text Available Nanofiltration and reverse osmosis are investigated as a possible alternative to the conventional methods of Cr(VI removal from model water and industrial effluent. The influences of feed concentration, water recovery, pH, and the coexisting anions were studied. The results have shown that retention rates of hexavalent chromium can reach 99.7% using nanofiltration membrane (NF-HL and vary from 85 to 99.9% using reverse osmosis membrane (RO-SG depending upon the composition of the solution and operating conditions. This work was also extended to investigate the separation of Cr(VI from car shock absorber factory effluent. The use of these membranes is very promising for Cr(VI water treatment and desalting industry effluent. Spiegler-Kedem model was applied to experimental results in the aim to determine phenomenological parameters, the reflection coefficient of the membrane (σ, and the solute permeability coefficient (Ps. The convective and diffusive parts of the mass transfer were quantified with predominance of the diffusive contribution.

  4. DRINKING WATER FROM DESALINATION OF SEAWATER: OPTIMIZATION OF REVERSE OSMOSIS SYSTEM OPERATING PARAMETERS

    Directory of Open Access Journals (Sweden)

    MARWAN M. SHAMEL

    2006-12-01

    Full Text Available This paper reports on the use of pilot scale membrane separation system coupled with another pilot scale plate heat exchanger to investigate the possibilities of sweetening seawater from Telok Kalong Beach, Terengganu, Malaysia. Reverse osmosis (RO membrane of a surface area of 0.5 m2 was used during the experimental runs. Experiments were conducted at different transmembrane pressures (TMP ranged from 40 to 55 bars, operation temperature ranged from 35 to 45oC, feed concentration (TDS ranged from 34900 to 52500 ppm and cross flow velocities ranged from 1.4 to 2.1 m/s. The result show that the flux values increased linearly with TMP as well as sodium ion rejection. Permeate flux values increased proportionally with the temperature and the later effect was more significant at high pressures. The temperature changing has also influenced the rejection of sodium ion. The minerals content especially NaCl and total dissolved solid (TDS in the drinking water produced in this research are conforming to the standards of World Health Organization (WHO.

  5. Chemical treatment of commercial reverse osmosis membranes for use in FO

    Science.gov (United States)

    Commercially available reverse osmosis (RO) membranes – SW30HR, BW30, and AG – were chemically treated for use in forward osmosis (FO). Nitric acid, phosphoric acid, sulfuric acid, ethanol, and ethanol–acid–water ternary solutions were employed for the treatment. All three membra...

  6. MODIFIED REVERSE OSMOSIS SYSTEM FOR TREATMENT OF PRODUCED WATERS

    Energy Technology Data Exchange (ETDEWEB)

    Robert L. Lee; Junghan Dong

    2004-06-03

    This final report of ''Modified Reverse Osmosis System for Treatment of Produced Water,'' DOE project No. DE-FC26-00BC15326 describes work performed in the third year of the project. Several good results were obtained, which are documented in this report. The compacted bentonite membranes were replaced by supported bentonite membranes, which exhibited the same salt rejection capability. Unfortunately, it also inherited the clay expansion problem due to water invasion into the interlayer spaces of the compacted bentonite membranes. We noted that the supported bentonite membrane developed in the project was the first of its kind reported in the literature. An {alpha}-alumina-supported MFI-type zeolite membrane synthesized by in-situ crystallization was fabricated and tested. Unlike the bentonite clay membranes, the zeolite membranes maintained stability and high salt rejection rate even for a highly saline solution. Actual produced brines from gas and oil fields were then tested. For gas fields producing brine, the 18,300 ppm TDS (total dissolved solids) in the produced brine was reduced to 3060 ppm, an 83.3% rejection rate of 15,240 ppm salt rejection. For oilfield brine, while the TDS was reduced from 181,600 ppm to 148,900 ppm, an 18% rejection rate of 32,700 ppm reduction, the zeolite membrane was stable. Preliminary results show the dissolved organics, mainly hydrocarbons, did not affect the salt rejection. However, the rejection of organics was inconclusive at this point. Finally, the by-product of this project, the {alpha}-alumina-supported Pt-Co/Na Y catalytic zeolite membrane was developed and demonstrated for overcoming the two-step limitation of nonoxidation methane (CH{sub 4}) conversion to higher hydrocarbons (C{sub 2+}) and hydrogen (H{sub 2}). Detailed experiments to obtain quantitative results of H{sub 2} generation for various conditions are now being conducted. Technology transfer efforts included five manuscripts submitted to

  7. Application of reverse osmosis membrane for separation of toxic metal in water

    International Nuclear Information System (INIS)

    Syahril Ahmad

    2010-01-01

    Experimental separation of toxic metal in water has been done using reverse osmosis membrane made from composite material. Experiment was done by simulation in which metals that will be observed solved with water in different concentration and then used as feed solution in reverse osmosis process. Metals observed were Cr"6"+, Mn"2"+ and Pb"2"+ and reverse osmosis process was done at pressure of 40 Bar for all metals. Experiment result showed that value of feed solution concentration would affect flux and coefficient rejection of membrane. Composite membrane with polyacrylamide as active layer of membrane can reject metals observed with value of rejection coefficient more than 90%, except for Mn"2"+metal that have concentration 250 ppm and 500 ppm. (author)

  8. The Development of a Renewable-Energy-Driven Reverse Osmosis System for Water Desalination and Aquaculture Production

    Institute of Scientific and Technical Information of China (English)

    Clark C K Liu

    2013-01-01

    Water and energy are closely linked natural resources-the transportation, treatment, and distribution of water depends on low-cost energy;while power generation requires large volumes of water. Seawater desalination is a mature technology for increasing freshwater supply, but it is essentially a trade of energy for freshwater and is not a viable solution for regions where both water and energy are in short supply. This paper discusses the development and application of a renewable-energy-driven reverse osmosis (RO) system for water desalination and the treatment and reuse of aquaculture wastewater. The system consists of (1) a wind-driven pumping subsystem, (2) a pressure-driven RO membrane desalination subsystem, and (3) a solar-driven feedback control module. The results of the pilot experiments indicated that the system, operated under wind speeds of 3 m s-1 or higher, can be used for brackish water desalination by reducing the salinity of feedwater with total dissolved solids (TDS) of over 3 000 mg L-1 to product water or permeate with a TDS of 200 mg L-1 or less. Results of the pilot experiments also indicated that the system can remove up to 97%of the nitrogenous wastes from the fish pond effluent and can recover and reuse up to 56%of the freshwater supply for fish pond operation.

  9. Sterile Reverse Osmosis Water Combined with Friction Are Optimal for Channel and Lever Cavity Sample Collection of Flexible Duodenoscopes

    Directory of Open Access Journals (Sweden)

    Michelle J. Alfa

    2017-11-01

    Full Text Available IntroductionSimulated-use buildup biofilm (BBF model was used to assess various extraction fluids and friction methods to determine the optimal sample collection method for polytetrafluorethylene channels. In addition, simulated-use testing was performed for the channel and lever cavity of duodenoscopes.Materials and methodsBBF was formed in polytetrafluorethylene channels using Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Sterile reverse osmosis (RO water, and phosphate-buffered saline with and without Tween80 as well as two neutralizing broths (Letheen and Dey–Engley were each assessed with and without friction. Neutralizer was added immediately after sample collection and samples concentrated using centrifugation. Simulated-use testing was done using TJF-Q180V and JF-140F Olympus duodenoscopes.ResultsDespite variability in the bacterial CFU in the BBF model, none of the extraction fluids tested were significantly better than RO. Borescope examination showed far less residual material when friction was part of the extraction protocol. The RO for flush-brush-flush (FBF extraction provided significantly better recovery of E. coli (p = 0.02 from duodenoscope lever cavities compared to the CDC flush method.Discussion and conclusionWe recommend RO with friction for FBF extraction of the channel and lever cavity of duodenoscopes. Neutralizer and sample concentration optimize recovery of viable bacteria on culture.

  10. Case Study of a Small Scale Reverse Osmosis System for Treatment of Mixed Brackish Water and STP Effluent

    Directory of Open Access Journals (Sweden)

    I Nyoman Widiasa

    2017-04-01

    Full Text Available A case study on utilizing reverse osmosis (RO technology to fulfill fresh water needs at a mall and a hotel has been done on Bali Island, Indonesia. A mix of brackish water and sewage treatment plant (STP effluent was used as feed water in the RO system. The system used 36 membrane elements (CSM RE 8040 BLN arranged into two stages: 8 pressure vessels (PVs in the first stage and 4 PVs in the second stage, each loaded with 3 membranes. The objectives of this research were to assess the cleaning effectivity in the plant, to evaluate the cleaning of 1 membrane element using a CIP system, and to assess the use of the membrane for filtration in the pre-treatment system. SEM and FTIR analysis indicated that the foulants on the membrane surface were dominated by organic foulants and inorganic deposits. To clean the discarded membrane the proposed method used NaOH solution (pH 12 and pH 13 and citric acid (pH 2 and pH 3. All membranes displayed a dramatic decline in rejection of about 80%. Based on the rejection tests of SO42-, Cl-, turbidity reduction approached 100%. It can be concluded that an RO membrane that has undergone selectivity decline can be re-used as a filtration membrane in the pre-treatment system.

  11. Forward Osmosis/Low Pressure Reverse Osmosis for Water Reuse: Removal of Organic Micropollutants, Fouling and Cleaning

    KAUST Repository

    Linares, Rodrigo

    2011-07-01

    Forward osmosis (FO) is a natural process in which a solution with high concentration of solutes is diluted when being in contact, through a semipermeable membrane, with a low concentration solution. This osmotic process has been demonstrated to be efficient to recover wastewater effluents while diluting a saline draw solution. Nevertheless, the study of the removal of micropollutants by FO is barely described in the literature. This research focuses on the removal of these substances spiked in a secondary wastewater effluent, while diluting water from the Red Sea, generating feed water that can be desalinated with a low pressure reverse osmosis (LPRO) system. Another goal of this work is to characterize the fouling of the FO membrane, and its effect on micropollutants rejection, as well as the membrane cleaning efficiency of different methods. When considering only FO with a clean membrane, the rejection of the hydrophilic neutral compounds was between 48.6% and 84.7%, for the hydrophobic neutrals the rejection ranged from 40.0% to 87.5%, and for the ionic compounds the rejections were between 92.9% and 96.5%. With a fouled membrane, the rejections were between 44.6% to 95.2%, 48.7% to 91.5% and 96.9% to 98.6%, respectively. These results suggest that, except for the hydrophilic neutral compounds, the rejection of the micropollutants is increased by the fouling layer, possibly due to the higher hydrophilicity of the FO fouled membrane compared to the clean one, the increased adsorption capacity and reduced mass transport capacity, membrane swelling, and the higher negative charge of the surface, related to the foulants. However, when coupled with low pressure reverse osmosis, the rejections for both, the clean and fouled membrane, increased above 98%. The fouling layer, after characterizing the wastewater effluent and the concentrated wastewater after the FO process, proved to be composed of biopolymers, which can be removed with air scouring during short periods

  12. Removal of haloacetic acids from swimming pool water by reverse osmosis and nanofiltration.

    Science.gov (United States)

    Yang, Linyan; She, Qianhong; Wan, Man Pun; Wang, Rong; Chang, Victor W-C; Tang, Chuyang Y

    2017-06-01

    Recent studies report high concentrations of haloacetic acids (HAAs), a prevalent class of toxic disinfection by-products, in swimming pool water (SPW). We investigated the removal of 9 HAAs by four commercial reverse osmosis (RO) and nanofiltration (NF) membranes. Under typical SPW conditions (pH 7.5 and 50 mM ionic strength), HAA rejections were >60% for NF270 with molecular weight cut-off (MWCO) equal to 266 Da and equal or higher than 90% for XLE, NF90 and SB50 with MWCOs of 96, 118 and 152 Da, respectively, as a result of the combined effects of size exclusion and charge repulsion. We further included 7 neutral hydrophilic surrogates as molecular probes to resolve the rejection mechanisms. In the absence of strong electrostatic interaction (e.g., pH 3.5), the rejection data of HAAs and surrogates by various membranes fall onto an identical size-exclusion (SE) curve when plotted against the relative-size parameter, i.e., the ratio of molecular radius over membrane pore radius. The independence of this SE curve on molecular structures and membrane properties reveals that the relative-size parameter is a more fundamental SE descriptor compared to molecular weight. An effective molecular size with the Stokes radius accounting for size exclusion and the Debye length accounting for electrostatic interaction was further used to evaluate the rejection. The current study provides valuable insights on the rejection of trace contaminants by RO/NF membranes. Copyright © 2017. Published by Elsevier Ltd.

  13. Performance of tubular reverse osmosis for the desalination ...

    African Journals Online (AJOL)

    Municipal solid waste leachate (MSWL) has the potential to pollute the water environment and to affect biological treatment processes adversely if not properly handled. Reverse osmosis (RO) has the ability to remove both organics and inorganics effectively from effluents. Therefore, RO was evaluated for the treatment of ...

  14. Effect of pH and Pressure on Uranium Removal from Drinking Water Using NF/RO Membranes.

    Science.gov (United States)

    Schulte-Herbrüggen, Helfrid M A; Semião, Andrea J C; Chaurand, Perrine; Graham, Margaret C

    2016-06-07

    Groundwater is becoming an increasingly important drinking water source. However, the use of groundwater for potable purposes can lead to chronic human exposure to geogenic contaminants, for example, uranium. Nanofiltration (NF) and reverse osmosis (RO) processes are used for drinking water purification, and it is important to understand how contaminants interact with membranes since accumulation of contaminants to the membrane surface can lead to fouling, performance decline and possible breakthrough of contaminants. During the current study laboratory experiments were conducted using NF (TFC-SR2) and RO (BW30) membranes to establish the behavior of uranium across pH (3-10) and pressure (5-15 bar) ranges. The results showed that important determinants of uranium-membrane sorption interactions were (i) the uranium speciation (uranium species valence and size in relation to membrane surface charge and pore size) and (ii) concentration polarization, depending on the pH values. The results show that it is important to monitor sorption of uranium to membranes, which is controlled by pH and concentration polarization, and, if necessary, adjust those parameters controlling uranium sorption.

  15. Evaluating the efficiency of different microfiltration and ultrafiltration membranes used as pretreatment for Red Sea water reverse osmosis desalination

    KAUST Repository

    Almashharawi, Samir

    2013-01-01

    Conventional processes are widely used as pretreatment for reverse osmosis (RO) desalination technology since its development. However, these processes require a large footprint and have some limitation issues such as difficulty to maintain a consistent silt density index, coagulation control at low total suspended solids, and management of higher waste sludge. Recently, there has been a rapid growth in the use of low-pressure membranes as pretreatment for RO systems replacing the conventional processes. However, despite the numerous advantages of using this integrated membrane system mainly providing good and stable water quality to RO membranes, many issues have to be addressed. The primary limitation is membrane fouling which reduces the permeate flux; therefore, higher pumping intensity is required to maintain a consistent volume of product. This paper aims to optimize the permeation flux and cleaning frequency by providing high permeate quality. Different low-pressure polyethersulfone membranes with different pore sizes ranging from 0.1 lm to 50 kDa were tested. Eight different filtration configurations have been applied including the variation of coagulant doses aiming to control membrane fouling. Results showed that all the configurations with/without coagulation, provided permeate with excellent water quality which improves the stability of RO performance. However, more stable fluxes with less-energy consumption were achieved by using the 0.1 lm and 100 kDa membranes with 1 mg/L FeCl3 coagulation. The use of UF membranes, having tight pores, without coagulation also proved to be an excellent option for Red Sea water RO pretreatment. © 2013 Desalination Publications.

  16. Biogenic nanosilver incorporated reverse osmosis membrane for antibacterial and antifungal activities against selected pathogenic strains: an enhanced eco-friendly water disinfection approach.

    Science.gov (United States)

    Manjumeena, R; Duraibabu, D; Sudha, J; Kalaichelvan, P T

    2014-01-01

    Reverse osmosis (RO) membranes have been used extensively in water desalination plants, waste water treatment in industries, agricultural farms and drinking water production applications. The objective of this work is to impart antibacterial and antifungal activities to commercially available RO membrane used in water purification systems by incorporating biogenic silver nanoparticles(AgNPs) synthesized using Rosa indica wichuriana hybrid leaf extract. The morphology and surface topography of uncoated and AgNPs-coated RO membrane were studied using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Elemental composition of the AgNPs-coated RO membrane was analyzed by energy-dispersive X-ray spectroscopy (EDAX). The functional groups were identified by Fourier Transform Infrared spectroscopy (FT-IR). Hydrophilicity of the uncoated and AgNPs-coated RO membrane was analyzed using water contact angle measurements. The thermal properties were studied by thermogravimetric analysis (TGA). The AgNPs incorporated RO membrane exhibited good antibacterial and antifungal activities against pathogenic bacterial strains such as E. coli, S. aureus, M. luteus, K. pneumoniae, and P. aeruginosa and fungal strains such as Candida tropicalis, C. krusei, C. glabrata, and C. albicans.

  17. Rejection of Emerging Organic Contaminants by Nanofiltration and Reverse Osmosis Membranes : Effects of Fouling, Modelling and Water Reuse

    NARCIS (Netherlands)

    Yangali Quintanilla, V.

    2010-01-01

    The book contains a description of the presence of micropollutants (medicines, hormones, pesticides) in surface water and shows that conventional water treatment poorly removes micropollutants. Nanofiltration and reverse osmosis are more appropriate technologies; however removals can vary depending

  18. Preparation and water desalination properties of POSS-polyamide nanocomposite reverse osmosis membranes

    KAUST Repository

    Duan, Jintang; Litwiller, Eric; Pinnau, Ingo

    2015-01-01

    osmosis membranes was systematically investigated. Four POSS materials (P-8Phenyl, P-8NH3Cl, P-8NH2 and P-1NH2) were introduced into the selective layer by physical blending or chemical fixation during standard interfacial polymerization. Water flux and Na

  19. A feasibility study of ultrafiltration/reverse osmosis (UF/RO)-based wastewater treatment and reuse in the metal finishing industry

    DEFF Research Database (Denmark)

    Petrinic, Irena; Korenak, Jasmina; Povodnik, Damijan

    2015-01-01

    that the ultrafiltration-reverse osmosis treatment removed between 91.3% and 99.8% of the contaminants from the effluent, such as metal elements, organic, and inorganic compounds. Contaminants such as suspended solids, nickel, ammonium nitrogen, sulphate nitrogen, chemical oxygen demand, and biochemical oxygen demand were...... completely removed, the concentrations in the permeate being under the detection limits, thus the quality of the ultrafiltration-reverse osmosis process met the reuse criteria. This demonstrates the technological feasibility of wastewater reuse during electro-plating processes and the pre-treatment of powder...

  20. Factors affecting fluoride and natural organic matter (NOM) removal from natural waters in Tanzania by nanofiltration/reverse osmosis.

    Science.gov (United States)

    Shen, Junjie; Schäfer, Andrea I

    2015-09-15

    This study examined the feasibility of nanofiltration (NF) and reverse osmosis (RO) in treating challenging natural tropical waters containing high fluoride and natural organic matter (NOM). A total of 166 water samples were collected from 120 sources within northern Tanzania over a period of 16 months. Chemical analysis showed that 81% of the samples have fluoride levels exceeding the WHO drinking guideline of 1.5mg/L. The highest fluoride levels were detected in waters characterized by high ionic strength, high inorganic carbon and on some occasions high total organic carbon (TOC) concentrations. Bench-scale experiments with 22 representative waters (selected based on fluoride concentration, salinity, origin and in some instances organic matter) and 6 NF/RO membranes revealed that ionic strength and recovery affected fluoride retention and permeate flux. This is predominantly due to osmotic pressure and hence the variation of diffusion/convection contributes to fluoride transport. Different membranes had distinct fluoride removal capacities, showing different raw water concentration treatability limits regarding the WHO guideline compliance. BW30, BW30-LE and NF90 membranes had a feed concentration limit of 30-40 mg/L at 50% recovery. NOM retention was independent of water matrices but is governed predominantly by size exclusion. NOM was observed to have a positive impact on fluoride removal. Several mechanisms could contribute but further studies are required before a conclusion could be drawn. In summary, NF/RO membranes were proved to remove both fluoride and NOM reliably even from the most challenging Tanzanian waters, increasing the available drinking water sources. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Exergy Analysis of a Two-Pass Reverse Osmosis (RO Desalination Unit with and without an Energy Recovery Turbine (ERT and Pressure Exchanger (PX

    Directory of Open Access Journals (Sweden)

    Nuri M. Eshoul

    2015-07-01

    Full Text Available This paper presents an exergy analysis of an actual two-pass (RO desalination system with the seawater solution treated as a real mixture and not an ideal mixture. The actual 127 ton/h two pass RO desalination plant was modeled using IPSEpro software and validated against operating data. The results show that using the (ERT and (PX reduced the total power consumption of the SWRO desalination by about 30% and 50% respectively, whereas, the specific power consumption for the SWRO per m3 water decreased from 7.2 kW/m3 to 5.0 kW/m3 with (ERT and 3.6 kW/m3 with (PX. In addition, the exergy efficiency of the RO desalination improved by 49% with ERT and 77% with PX and exergy destruction was reduced by 40% for (ERT and 53% for (PX. The results also showed that, when the (ERT and (PX were not in use, accounted for 42% of the total exergy destruction. Whereas, when (ERT and (PX are in use, the rejected seawater account maximum is 0.64%. Moreover, the (PX involved the smallest area and highest minimum separation work.

  2. Selection of inorganic-based fertilizers in forward osmosis for water desalination

    Directory of Open Access Journals (Sweden)

    Tripti Mishra

    2015-06-01

    Full Text Available The current study aims at the selection of an appropriate draw solute for forward osmosis process. Separation and recovery of the draw solute are the major criteria for the selection of draw solute for forward osmosis process. Therefore in this investigation six inorganic fertilizers draws solute were selected. The selections of inorganic fertilizers as draw solute eliminate the need of removal and recovery of draw solute from the final product. The final product water of forward osmosis process has direct application in agricultural as nutrient rich water for irrigation. These inorganic fertilizers were tested based on their water extraction (water flux capacity. This experimental water flux was compared with the observed water flux. It was noted that the observed water flux is much higher than the attained experimental water flux. The difference of these two fluxes was used to calculate the performance ratio of each selected fertilizer. Highest performance ratio was shown by low molecular weight compound ammonium nitrate (22.73 and potassium chloride (21.03 at 1 M concentration, whereas diammonium phosphate (DAP which has highest molecular weight among all the selected fertilizer show the lowest performance ratio (10.02 at 2 M concentration. DOI: http://dx.doi.org/10.3126/ije.v4i2.12660 International Journal of Environment Vol.4(2 2015: 319-329

  3. Med-Ro Hybrid desalination as option to supply fresh water in BABEL Islands Province

    International Nuclear Information System (INIS)

    Siti Alimah; Sudi Ariyanto; June Mellawati; Budiarto

    2011-01-01

    Med-Ro hybrid desalination systems are combining both thermal (Med) and membrane (Ro) desalination processes with power generation systems. This configuration has more economical and operational benefits in comparison with single desalination plant. Hybrid configurations are characterized by flexibility in operation, specific energy consumption (33.50 kWh/m 3 ) is lower than Med (36.54 kWh/m 3 ) and high plant availability. The objective of study is to analyze the Med-Ro hybrid desalination as an option to add supply fresh water in Babel Islands Province, in terms of technology and economy aspects. The result of study showed that adopting nuclear power plants as dual-purpose for power generation and producing fresh water is has economic competitiveness than fossil-fired generation plants. Med-Ro hybrid configuration, with feed Ro from heat rejection of Med system is suitable as fresh water supply add option because increase of Ro feed temperature will increase flux. Economic analysis of water cost are performed using the Deep-3.2. Water cost of hybrid Med-Ro desalination with energy of NPP (0.581 $/m ) is lower than that of Med water cost (0.752 $/m ) . Water cost of hybrid Med-Ro with energy of NPP (0.581 $/m ) is lower than that of water cost of energy with fossil-fired generation plants (0.720 $/m 3 ). (author)

  4. Reverse Osmosis

    Indian Academy of Sciences (India)

    Osmosis is a phenomenon which regulates many biological functions in plants and animals. That the plants stand upright, or the water reaches the tip of every leaf of a plant is due to osmotic pressure. The fact that we cannot survive by drinking seawater is also linked to this same phenomenon. J H van 't. Hoff showed in ...

  5. Experiences on sea water reverse osmosis plant at Anuvijay township, Kudankulam Nuclear Power Plant

    International Nuclear Information System (INIS)

    Balasubramanian, M.R.; Selvavinayagam, P.; Singaravelan, S.; Ramdoss, R.; Sundar, R.S.

    2007-01-01

    Sea water reverse Osmosis plant SWRO of KKNPP is located at Anuvijay township, Chettikulam, Tirunelveli District, Tamilnadu. The objective of SWRO is to produce 2400 M 3 of potable quality water per day. This plant consists of four streams, each having a capacity of 25 M 3 /hr. Each stream is having 9 pressure tube in parallel and each pressure tube has 6 polyamide spiral wound membrane in series. (author)

  6. Environmental and economic assessment of hybrid FO-RO/NF system with selected inorganic draw solutes for the treatment of mine impaired water

    KAUST Repository

    Kim, Jung Eun

    2018-01-01

    A hybrid forward osmosis (FO) and reverse osmosis (RO)/nanofiltration (NF) system in a closed-loop operation with selected draw solutes was evaluated to treat coal mine impaired water. This study provides an insight of selecting the most suitable draw solution (DS) by conducting environmental and economic life cycle assessment (LCA). Baseline environmental LCA showed that the dominant components to energy use and global warming are the DS recovery processes (i.e. RO or NF processes) and FO membrane materials, respectively. When considering the DS replenishment in FO, the contribution of chemical use to the overall global warming impact was significant for all hybrid systems. Furthermore, from an environmental perspective, the FO-NF hybrid system with Na2SO4 shows the lowest energy consumption and global warming with additional considerations of final product water quality and FO brine disposal. From an economic perspective, the FO-NF with Na2SO4 showed the lowest total operating cost due to its lower DS loss and relatively low solute cost. In a closed-loop system, FO-NF with NaCl and Na2SO4 had the lowest total water cost at optimum NF recovery rates of 90 and 95%, respectively. FO-NF with Na2SO4 had the lowest environmental and economic impacts. Overall, draw solute performances and cost in FO and recovery rate in RO/NF play a crucial role in determining the total water cost and environmental impact of FO hybrid systems in a closed-loop operation.

  7. Reverse Osmosis

    Indian Academy of Sciences (India)

    many applications, one of which is desalination of seawater. The inaugural Nobel Prize in Chemistry was awarded in 1901 to van 't Hoff for his seminal work in this area. The present article explains the principle of osmosis and reverse osmosis. Osmosis and Reverse Osmosis. As the name suggests, reverse osmosis is the ...

  8. A 5 year longitudinal study of water quality for final rinsing in the single chamber washer-disinfector with a reverse osmosis plant.

    Science.gov (United States)

    Uetera, Yushi; Kishii, Kozue; Yasuhara, Hiroshi; Kumada, Naohito; Moriya, Kyoji; Saito, Ryoichi; Okazaki, Mitsuhiro; Misawa, Yoshiki; Kawamura, Kunio

    2013-01-01

    This report deals with the construction and management of the reverse osmosis (RO) water system for final rinsing of surgical instruments in the washer-disinfector. Numerous operational challenges were encountered in our RO water system and these were analyzed utilizing the Ishikawa Fishbone diagram. The aim was to find potential problems and promote preventive system management for RO water. It was found that the measures that existed were inappropriate for preventing contamination in the heat-labile RO water system. The storage tank was found to be significantly contaminated and had to be replaced with a new one equipped with a sampling port and water drainage system. Additional filters and an UV treatment lamp were installed. The whole system disinfection started 1.5 years later using a peracetic acid-based compound after confirming the material compatibility. Operator errors were found when a new water engineer took over the duty from his predecessor. It was also found that there were some deficiencies in the standard operating procedures (SOPs), and that on-the-job training was not enough. The water engineer failed to disinfect the sampling port and water drainage system. The RO membrane had been used for 4 years, even though the SOP standard specified changing it as every 3 years. Various bacteria, such as Rothia mucilaginosa, were cultured from the RO water sampled from the equipment. Because Rothia mucilaginosa is a resident in the oral cavity and upper respiratory tract, it is believed that the bacteria were introduced into the system by the maintenance personnel or working environment. Therefore, the presence of R. mucilaginosa implied the failure of sanitary maintenance procedures. This study suggests that water systems should be designed based on the plans for profound system maintenance. It also suggests that SOP and on-the job training are essential to avoid any operator errors. These results must be carefully considered when either constructing new

  9. Life cycle cost of a hybrid forward osmosis – low pressure reverse osmosis system for seawater desalination and wastewater recovery

    KAUST Repository

    Valladares Linares, Rodrigo

    2015-10-19

    In recent years, forward osmosis (FO) hybrid membrane systems have been investigated as an alternative to conventional high-pressure membrane processes (i.e. reverse osmosis (RO)) for seawater desalination and wastewater treatment and recovery. Nevertheless, their economic advantage in comparison to conventional processes for seawater desalination and municipal wastewater treatment has not been clearly addressed. This work presents a detailed economic analysis on capital and operational expenses (CAPEX and OPEX) for: i) a hybrid forward osmosis – low-pressure reverse osmosis (FO-LPRO) process, ii) a conventional seawater reverse osmosis (SWRO) desalination process, and iii) a membrane bioreactor – reverse osmosis – advanced oxidation process (MBR-RO-AOP) for wastewater treatment and reuse. The most important variables affecting economic feasibility are obtained through a sensitivity analysis of a hybrid FO-LPRO system. The main parameters taken into account for the life cycle costs are the water quality characteristics (similar feed water and similar water produced), production capacity of 100,000 m3 d−1 of potable water, energy consumption, materials, maintenance, operation, RO and FO module costs, and chemicals. Compared to SWRO, the FO-LPRO systems have a 21% higher CAPEX and a 56% lower OPEX due to savings in energy consumption and fouling control. In terms of the total water cost per cubic meter of water produced, the hybrid FO-LPRO desalination system has a 16% cost reduction compared to the benchmark for desalination, mainly SWRO. Compared to the MBR-RO-AOP, the FO-LPRO systems have a 7% lower CAPEX and 9% higher OPEX, resulting in no significant cost reduction per m3 produced by FO-LPRO. Hybrid FO-LPRO membrane systems are shown to have an economic advantage compared to current available technology for desalination, and comparable costs with a wastewater treatment and recovery system. Based on development on FO membrane modules, packing density, and

  10. Apparatus, System, and Method for Forward Osmosis in Water Reuse

    KAUST Repository

    Yangali-Quintanilla, Victor; Li, Zhenyu; Valladares Linares, Rodrigo; Amy, Gary

    2013-01-01

    An apparatus, system, and method for desalinating water is presented. The invention relates to recovery of water from impaired water sources by using FO and seawater as draw solution (DS). The seawater becomes diluted over time and can be easily

  11. Reverse osmosis, the solution for producing steam from highly saline water; Osmosis inversa, la solucion para la produccion de vapor con aguas de alta salinidad

    Energy Technology Data Exchange (ETDEWEB)

    Pujadas, A.

    2003-07-01

    Based on an exhaustive description of a particular example, the costs of installing an implementing various water treatment solutions for feeding a steam boiler are examined. When the characteristics of the water available indicate that it has a high saline content, i is possible to demonstrate the enormous technical, economic and environmental advantages of reducing its saline level by a system of reverse osmosis compared to the classical ion exchange resins. A list is given of the features to be taken into account in defining the equipment involved in treating the water for feeding steam boilers. (Author)

  12. A review of reverse osmosis membrane materials for desalination-Development to date and future potential

    OpenAIRE

    Lee, Kali Peng; Arnot, Tom C.; Mattia, Davide

    2011-01-01

    Reverse osmosis (RO) is currently the most important desalination technology and it is experiencing significant growth. The objective of this paper is to review the historical and current development of RO membrane materials which are the key determinants of separation performance and water productivity, and hence to define performance targets for those who are developing new RO membrane materials. The chemistry, synthesis mechanism(s) and desalination performance of various RO membranes are ...

  13. Treatment of reverse osmosis (RO) concentrate by the combined Fe/Cu/air and Fenton process (1stFe/Cu/air-Fenton-2ndFe/Cu/air).

    Science.gov (United States)

    Ren, Yi; Yuan, Yue; Lai, Bo; Zhou, Yuexi; Wang, Juling

    2016-01-25

    To decompose or transform the toxic and refractory reverse osmosis (RO) concentrate and improve the biodegradability, 1stFe/Cu/air-Fenton-2ndFe/Cu/air were developed to treat RO concentrate obtained from an amino acid production plant in northern China. First, their operating conditions were optimized thoroughly. Furthermore, 5 control experiments were setup to confirm the superiority of 1stFe/Cu/air-Fenton-2ndFe/Cu/air and synergistic reaction between Fe/Cu/air and Fenton. The results suggest that the developed method could obtain high COD removal (65.1%) and BOD5/COD ratio (0.26) due to the synergistic reaction between Fe/Cu/air and Fenton. Under the optimal conditions, the influent and effluent of 1stFe/Cu/air-Fenton-2ndFe/Cu/air and 5 control experiments were analyzed by using UV, FTIR, EEM and LC, which confirm the superiority of 1stFe/Cu/air-Fenton-2ndFe/Cu/air. Therefore, the developed method in this study is a promising process for treatment of RO concentrate. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. 10 years of make-up water treatment with integrated reverse osmosis at Grosskraftwerk Mannheim

    International Nuclear Information System (INIS)

    Spindler, K.; Bloechl, H.; Bursik, A.

    1993-01-01

    Since 1982, at Grosskraftwerk Mannheim, a make-up water treatment in which three reverse osmosis plants are integrated, has been operating. The original high-pressure hollow fibre module of these plants has been replaced by low-pressure coil modules. The reasons for the change in system are described in the paper. In the low-pressure plant, coil modules have been installed by several manufacturers. The paper reports on experience with the low-pressure elements. The experience gained has been streamed into the planning proposals for the new make-up water treatment plant. (orig.) [de

  15. Learning about (Not by) Osmosis.

    Science.gov (United States)

    Borovoy, Alexander

    1991-01-01

    Describes the process of osmosis from its discovery by Nollet in 1848 to modern applications. Uses experimental descriptions, illustrations, and photographs to explain osmosis. Discusses the technology of producing perfect filters and their applications in reverse osmosis to purify salt water and to filter blood in kidney machines. (PR)

  16. Evaluation of the use of reverse osmosis to eliminate natural radionuclides from water samples.

    Science.gov (United States)

    Nieto, Antonio; Palomo, Marta; Ruana, Josep; Peñalver, Alejandra; Aguilar, Carme; Borrull, Francesc

    2013-12-01

    The objective of drinking water treatment plants (DWTP) is to supply the population with tap water that is in optimal condition and in compliance with water quality regulations. In the DWTP of L'Ampolla (Tarragona, Spain), slightly high values of gross alpha activity and the amount of salts in the raw water have been observed. Conventional treatment has reduced these levels only minimally. This study tested a tertiary treatment based on reverse osmosis is tested in an industrial pilot plant (240 m3/day) The efficiency of this pilot plant to reduce the gross alpha and beta activities and the activity of some individual radioisotopes (U(238), U(234), U(235) and Ra(226)) was tested. Results showed that the elimination of alpha emitters was greater than 90%, whereas the elimination of beta emitters was about 35%. Overall, the data provided evidence that the pilot plant is effective for removing different radionuclides that can be present in the incoming water treated. Therefore, tertiary treatment based on reverse osmosis has a positive effect in water quality.

  17. Highly Water-Soluble Magnetic Nanoparticles as Novel Draw Solutes in Forward Osmosis for Water Reuse

    KAUST Repository

    Ling, Ming Ming

    2010-06-16

    Highly hydrophilic magnetic nanoparticles have been molecularly designed. For the first time, the application of highly water-soluble magnetic nanoparticles as novel draw solutes in forward osmosis (FO) was systematically investigated. Magnetic nanoparticles functionalized by various groups were synthesized to explore the correlation between the surface chemistry of magnetic nanoparticles and the achieved osmolality. We verified that magnetic nanoparticles capped with polyacrylic acid can yield the highest driving force and subsequently highest water flux among others. The used magnetic nanoparticles can be captured by the magnetic field and recycled back into the stream as draw solutes in the FO process. In addition, magnetic nanoparticles of different diameters were also synthesized to study the effect of particles size on FO performance. We demonstrate that the engineering of surface hydrophilicity and magnetic nanoparticle size is crucial in the application of nanoparticles as draw solutes in FO. It is believed that magnetic nanoparticles will soon be extensively used in this area. © 2010 American Chemical Society.

  18. Sensory quality of drinking water produced by reverse osmosis membrane filtration followed by remineralisation.

    Science.gov (United States)

    Vingerhoeds, Monique H; Nijenhuis-de Vries, Mariska A; Ruepert, Nienke; van der Laan, Harmen; Bredie, Wender L P; Kremer, Stefanie

    2016-05-01

    Membrane filtration of ground, surface, or sea water by reverse osmosis results in permeate, which is almost free from minerals. Minerals may be added afterwards, not only to comply with (legal) standards and to enhance chemical stability, but also to improve the taste of drinking water made from permeate. Both the nature and the concentrations of added minerals affect the taste of the water and in turn its acceptance by consumers. The aim of this study was to examine differences in taste between various remineralised drinking waters. Samples selected varied in mineral composition, i.e. tap water, permeate, and permeate with added minerals (40 or 120 mg Ca/L, added as CaCO3, and 4 or 24 mg Mg/L added as MgCl2), as well as commercially available bottled drinking waters, to span a relevant product space in which the remineralised samples could be compared. All samples were analysed with respect to their physical-chemical properties. Sensory profiling was done by descriptive analysis using a trained panel. Significant attributes included taste intensity, the tastes bitter, sweet, salt, metal, fresh and dry mouthfeel, bitter and metal aftertaste, and rough afterfeel. Total dissolved solids (TDS) was a major determinant of the taste perception of water. In general, lowering mineral content in drinking water in the range examined (from water from fresh towards bitter, dry, and rough sensations. In addition, perceived freshness of the waters correlated positively with calcium concentration. The greatest fresh taste was found for water with a TDS between 190 and 350 mg/L. Remineralisation of water after reverse osmosis can improve drinking quality significantly. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Forward and pressure retarded osmosis: potential solutions for global challenges in energy and water supply.

    Science.gov (United States)

    Klaysom, Chalida; Cath, Tazhi Y; Depuydt, Tom; Vankelecom, Ivo F J

    2013-08-21

    Osmotically driven membrane processes (ODMP) have gained renewed interest in recent years and they might become a potential solution for the world's most challenging problems of water and energy scarcity. Though the concept of utilizing osmotic pressure difference between high and low salinity streams across semipermeable membranes has been explored for several decades, lack of optimal membranes and draw solutions hindered competition between forward osmosis (FO) and pressure retarded osmosis (PRO) with existing water purification and power generation technologies, respectively. Driven by growing global water scarcity and by energy cost and negative environmental impacts, novel membranes and draw solutions are being developed for ODMPs, mass and heat transfer in osmotic process are becoming better understood, and new applications of ODMPs are emerging. Therefore, OMDPs might become promising green technologies to provide clean water and clean energy from abundantly available renewable resources. This review focuses primarily on new insights into osmotic membrane transport mechanisms and on novel membranes and draw solutions that are currently being developed. Furthermore, the effects of operating conditions on the overall performance of osmotic membranes will be highlighted and future perspectives will be presented.

  20. Study of reverse osmosis applicability to light water reactor radwaste processing

    International Nuclear Information System (INIS)

    Markind, J.; Van Tran, T.

    1978-12-01

    Objectives were to collect and evaluate documented performance data of existing reverse-osmosis/ultrafiltration processes utilized for treating low-level liquid radioactive wastes, originating from light-water-reactor (LWR) nuclear power plants. Relevant information was collected by communication both written and verbal with membrane experts known to be active in the nuclear industry, and by conducting manual and computer searches. The generated information was evaluated on the basis of membrane performance characteristics relevant to nuclear engineering system analysis. 39 figures, 34 tables

  1. Thermodynamic advantages of nuclear desalination through reverse osmosis

    International Nuclear Information System (INIS)

    Bhattacharyya, K.P.; Prabhakar, S.; Tewari, P.K.

    2009-01-01

    Seawater Reverse Osmosis (SWRO) integrated with nuclear power station has significant thermodynamic advantages since it can utilize the waste heat available in the condenser cooling circuit and electrical power from the nuclear power plant with provision for using grid power in case of exigencies and shared infrastructure. Coupling of RO plants to the reactor is simple and straightforward and power loss due to RO unit, resulting in the loss of load, does not impact reactor turbine. Product water contamination probability is also very less since it has in-built mechanical barrier. Preheat reverse osmosis desalination has many thermodynamic advantages and studies have indicated improved performance characteristics thereby leading to savings in operational cost. The significant advantages include the operational flexibility of the desalination systems even while power plant is non-operational and non-requirement of safety systems for resource utilization. This paper brings out a comprehensive assessment of reverse osmosis process as a stand-alone nuclear desalination system. (author)

  2. Performance of high-recovery recycling reverse osmosis with wash water

    Science.gov (United States)

    Herrmann, Cal C.

    1993-01-01

    Inclusion of a recycling loop for partially-desalted water from second-stage reverse-osmosis permeate has been shown useful for achieving high-recovery at moderate applied pressures. This approach has now been applied to simulated wash waters, to obtain data on retention by the membranes of solutes in a mixture comparable to anticipated spacecraft hygiene wastewaters, and to generate an estimate of the maximum concentration that can be expected without causing membrane fouling. A first experiment set provides selectivity information from a single membrane and an Igepon detergent, as a function of final concentration. A reject concentration of 3.1% Total Organic Carbon has been reached, at a pressure of 1.4 Mega Pascals, without membrane fouling. Further experiments have generated selectivity values for the recycle configuration from two washwater simulations, as a function of applied pump pressure. Reverse osmosis removal has also been tested for washwater containing detergent formulated for plant growth compatibility (containing nitrogen, phosphorous and potassium functional groups.)

  3. Biological Water Processor and Forward Osmosis Secondary Treatment

    Science.gov (United States)

    Shull, Sarah; Meyer, Caitlin

    2014-01-01

    The goal of the Biological Water Processor (BWP) is to remove 90% organic carbon and 75% ammonium from an exploration-based wastewater stream for four crew members. The innovative design saves on space, power and consumables as compared to the ISS Urine Processor Assembly (UPA) by utilizing microbes in a biofilm. The attached-growth system utilizes simultaneous nitrification and denitrification to mineralize organic carbon and ammonium to carbon dioxide and nitrogen gas, which can be scrubbed in a cabin air revitalization system. The BWP uses a four-crew wastewater comprised of urine and humidity condensate, as on the ISS, but also includes hygiene (shower, shave, hand washing and oral hygiene) and laundry. The BWP team donates 58L per day of this wastewater processed in Building 7.

  4. Experimental Study of Advanced Treatment of Coking Wastewater Using MBR-RO Combined Process

    Science.gov (United States)

    Zhang, Lei; Hwang, Jiannyang; Leng, Ting; Xue, Gaifeng; Chang, Hongbing

    A membrane bioreactor-reverse osmosis (MBR-RO) combined process was used for advanced treatment of coking wastewater from secondary biological treatment. MBR and RO units' treatment efficiency for the pollution removal were conducted, and effects of raw water conductivity and trans-membrane pressure on water yield and desalination rate in RO unit were investigated in detail. The experimental results proved that MBR-RO combined process ran steadily with good treatment effect, which could obtain stable effluent water quality and met the requirement of "Design Criterion of the Industrial Circulating Cooling Water Treatment" (GB 50050-2007).

  5. Second law analysis of reverse osmosis desalination plants: An alternative design using pressure retarded osmosis

    International Nuclear Information System (INIS)

    Sharqawy, Mostafa H.; Zubair, Syed M.; Lienhard, John H.

    2011-01-01

    A second law analysis of a reverse osmosis desalination plant is carried out using reliable seawater exergy formulation instead of a common model in literature that represents seawater as an ideal mixture of liquid water and solid sodium chloride. The analysis is performed using reverse osmosis desalination plant data and compared with results previously published using the ideal mixture model. It is demonstrated that the previous model has serious shortcomings, particularly with regard to calculation of the seawater flow exergy, the minimum work of separation, and the second law efficiency. The most up-to-date thermodynamic properties of seawater, as needed to conduct an exergy analysis, are given as correlations in this paper. From this new analysis, it is found that the studied reverse osmosis desalination plant has very low second law efficiency (<2%) even when using the available energy recovery systems. Therefore, an energy recovery system is proposed using the (PRO) pressure retarded osmotic method. The proposed alternative design has a second law efficiency of 20%, and the input power is reduced by 38% relative to original reverse osmosis system. -- Highlights: ► A previously proposed model for the calculation of seawater flow exergy gives incorrect values. ► Reverse osmosis desalination plants have very low second law efficiency (<2%) even when using the available energy recovery systems. ► A PRO energy recovery device increases the RO plant’s second law efficiency to 20% and reduces the input power.

  6. Energy consumption in membrane capacitive deionization for different water recoveries and flow rates, and comparison with reverse osmosis

    NARCIS (Netherlands)

    Zhao, R.; Porada, S.; Biesheuvel, P.M.; Wal, van der A.

    2013-01-01

    Membrane capacitive deionization (MCDI) is a non-faradaic, capacitive technique for desalinating brackish water by adsorbing ions in charged porous electrodes. To compete with reverse osmosis, the specific energy consumption of MCDI needs to be reduced to less than 1 kWh per m3 of freshwater

  7. Speech and Language Disorders in a Dialysis Encephalopathy Patient and the Effect of Desferrioxamine and Reverse-Osmosis Water Treatment.

    Science.gov (United States)

    Lehtihalmes, Matti; And Others

    Dialysis encephalopathy is a progressive neurological disorder occurring after long-term hemodialysis in some renal failure patients. Accumulation of aluminum in the brain is suspected as its cause, and the use of reverse osmosis of the dialysis water and administration of desferrioxamine to the patient have been successful in reducing the…

  8. Treatment of tailings water from uranium ore processing by reverse osmosis

    International Nuclear Information System (INIS)

    Georgescu, D.P.; Andrei, L.

    2000-01-01

    Mining and metallurgical waste waters are considered to be the major sources of heavy metal contamination. The need of economic and effective methods for metals removal have resulted in the development of new separation technologies. Precipitation, ion exchange, electrochemical processes, filtration and flotation are commonly applied for industrial effluents treatment. Occasionally, the application of such processes is limited because of technical or economical constraints. The search for new technologies regarding the recovery and removal of toxic metals from waste waters has directed attention to membrane processes. These processes are developed in the recent years due to the availability of many new types of membranes. This paper presents the laboratory test results for liquid radioactive effluent treatment from alkaline uranium ore processing by reverse osmosis. (author)

  9. A Comparison of Water Diffusion in Polymer Based Fuel Cell and Reverse Osmosis Membrane Materials

    Science.gov (United States)

    Soles, Christopher; Frieberg, Bradley; Tarver, Jacob; Tyagi, Madhusudan; Jeong, Cheol; Chan, Edwin; Stafford, Christopher

    Hydrated polymer membranes are critical in both fuel cells and water filtration and desalination. In both of these applications the membrane function (selectively transporting or separating ions) is coupled with the transport of water through the membrane. There is a significant need to understand the nature by which the water and ions distribute and move through these membranes. This presentation compares the transport mechanisms in in an ion containing block copolymer alkaline fuel cell membrane with that of a polyamide membrane that is used as the active layer in a reverse osmosis water desalination membrane. Small angle neutron scattering measurements are used to locally probe how water swells the different materials and quantitatively describe the distribution of water within the membrane microstructures. Quasielastic neutron scattering measurements are then used to separate the polymer dynamics of the host membranes from the dynamics of the water inside the membranes. This reveals that water moves at least an order of magnitude slower through the ion containing fuel cell membrane materials, consistent with a solution-diffusion model, while the water in the polyamide membranes moves faster, consistent with a pore-flow diffusion mechanism. These insights will be discussed in terms of a coupling of the water and polymer dynamics and design cues for high performance membrane materials.

  10. Application of volume-retarded osmosis and low-pressure membrane hybrid process for water reclamation

    KAUST Repository

    Im, Sung-Ju

    2017-11-15

    A new concept of volume-retarded osmosis and low-pressure membrane (VRO-LPM) hybrid process was developed and evaluated for the first time in this study. Commercially available forward osmosis (FO) and ultrafiltration (UF) membranes were employed in a VRO-LPM hybrid process to overcome energy limitations of draw solution (DS) regeneration and production of permeate in the FO process. To evaluate its feasibility as a water reclamation process, and to optimize the operational conditions, cross-flow FO and dead-end mode UF processes were individually evaluated. For the FO process, a DS concentration of 0.15 g mL−1 of polysulfonate styrene (PSS) was determined to be optimal, having a high flux with a low reverse salt flux. The UF membrane with a molecular weight cut-off of 1 kDa was chosen for its high PSS rejection in the LPM process. As a single process, UF (LPM) exhibited a higher flux than FO, but this could be controlled by adjusting the effective membrane area of the FO and UF membranes in the VRO-LPM system. The VRO-LPM hybrid process only required a circulation pump for the FO process. This led to a decrease in the specific energy consumption of the VRO-LPM process for potable water production, that was similar to the single FO process. Therefore, the newly developed VRO-LPM hybrid process, with an appropriate DS selection, can be used as an energy efficient water production method, and can outperform conventional water reclamation processes.

  11. Application of volume-retarded osmosis and low-pressure membrane hybrid process for water reclamation

    KAUST Repository

    Im, Sung-Ju; Choi, Jungwon; Lee, Jung Gil; Jeong, Sanghyun; Jang, Am

    2017-01-01

    A new concept of volume-retarded osmosis and low-pressure membrane (VRO-LPM) hybrid process was developed and evaluated for the first time in this study. Commercially available forward osmosis (FO) and ultrafiltration (UF) membranes were employed in a VRO-LPM hybrid process to overcome energy limitations of draw solution (DS) regeneration and production of permeate in the FO process. To evaluate its feasibility as a water reclamation process, and to optimize the operational conditions, cross-flow FO and dead-end mode UF processes were individually evaluated. For the FO process, a DS concentration of 0.15 g mL−1 of polysulfonate styrene (PSS) was determined to be optimal, having a high flux with a low reverse salt flux. The UF membrane with a molecular weight cut-off of 1 kDa was chosen for its high PSS rejection in the LPM process. As a single process, UF (LPM) exhibited a higher flux than FO, but this could be controlled by adjusting the effective membrane area of the FO and UF membranes in the VRO-LPM system. The VRO-LPM hybrid process only required a circulation pump for the FO process. This led to a decrease in the specific energy consumption of the VRO-LPM process for potable water production, that was similar to the single FO process. Therefore, the newly developed VRO-LPM hybrid process, with an appropriate DS selection, can be used as an energy efficient water production method, and can outperform conventional water reclamation processes.

  12. Application of volume-retarded osmosis and low-pressure membrane hybrid process for water reclamation.

    Science.gov (United States)

    Im, Sung-Ju; Choi, Jungwon; Lee, Jung-Gil; Jeong, Sanghyun; Jang, Am

    2018-03-01

    A new concept of volume-retarded osmosis and low-pressure membrane (VRO-LPM) hybrid process was developed and evaluated for the first time in this study. Commercially available forward osmosis (FO) and ultrafiltration (UF) membranes were employed in a VRO-LPM hybrid process to overcome energy limitations of draw solution (DS) regeneration and production of permeate in the FO process. To evaluate its feasibility as a water reclamation process, and to optimize the operational conditions, cross-flow FO and dead-end mode UF processes were individually evaluated. For the FO process, a DS concentration of 0.15 g mL -1 of polysulfonate styrene (PSS) was determined to be optimal, having a high flux with a low reverse salt flux. The UF membrane with a molecular weight cut-off of 1 kDa was chosen for its high PSS rejection in the LPM process. As a single process, UF (LPM) exhibited a higher flux than FO, but this could be controlled by adjusting the effective membrane area of the FO and UF membranes in the VRO-LPM system. The VRO-LPM hybrid process only required a circulation pump for the FO process. This led to a decrease in the specific energy consumption of the VRO-LPM process for potable water production, that was similar to the single FO process. Therefore, the newly developed VRO-LPM hybrid process, with an appropriate DS selection, can be used as an energy efficient water production method, and can outperform conventional water reclamation processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Effect of water temperature on biofouling development in reverse osmosis membrane systems

    KAUST Repository

    Farhat, Nadia

    2016-07-14

    Understanding the factors that determine the spatial and temporal biofilm development is a key to formulate effective control strategies in reverse osmosis membrane systems for desalination and wastewater reuse. In this study, biofilm development was investigated at different water temperatures (10, 20, and 30 °C) inside a membrane fouling simulator (MFS) flow cell. The MFS studies were done at the same crossflow velocity with the same type of membrane and spacer materials, and the same feed water type and nutrient concentration, differing only in water temperature. Spatially resolved biofilm parameters such as oxygen decrease rate, biovolume, biofilm spatial distribution, thickness and composition were measured using in-situ imaging techniques. Pressure drop (PD) increase in time was used as a benchmark as to when to stop the experiments. Biofilm measurements were performed daily, and experiments were stopped once the average PD increased to 40 mbar/cm. The results of the biofouling study showed that with increasing feed water temperature (i) the biofilm activity developed faster, (ii) the pressure drop increased faster, while (iii) the biofilm thickness decreased. At an average pressure drop increase of 40 mbar/cm over the MFS for the different feed water temperatures, different biofilm activities, structures, and quantities were found, indicating that diagnosis of biofouling of membranes operated at different or varying (seasonal) feed water temperatures may be challenging. Membrane installations with a high temperature feed water are more susceptible to biofouling than installations fed with low temperature feed water.

  14. Energy efficient and adiabatic humidification. Reversed osmosis principle purifies water; Energiezuinig en adiabatisch bevochtigen. Omgekeerd-osmose principe zuivert water

    Energy Technology Data Exchange (ETDEWEB)

    Brands, R. [Cumulus Nederland, Cuijk (Netherlands)

    2006-11-15

    For decades air conditioners are equipped with humidifiers. A large number of humidifier types are available. Adiabatic humidification is an energy efficient technique, although it is important to control the installation conditions, water treatment (reversed osmosis) and the risk of legionella. [Dutch] Al decennia lang worden er luchtbehandelingkasten gebouwd met een bevochtigingssectie. Door de jaren heen is een enorme verscheidenheid ontstaan van bevochtigingssystemen. Adiabatische bevochtiging staat in de belangstelling vanwege het lagere energiegebruik. Hierbij moeten de installatievoorwaarden, de waterbehandeling (omgekeerde osmose) en het legionellarisico goed in de gaten worden gehouden.

  15. Microbial community analysis of fouled reverse osmosis membranes used in water recycling

    KAUST Repository

    Ayache, C.; Manes, Carmem Lara De O; Pidou, Marc; Croue, Jean-Philippe; Gernjak, Wolfgang

    2013-01-01

    Biofouling on RO membranes has major cost implications in water reclamation. In this study membranes and water samples were collected from a RO pilot-plant operated on two sites to study the differences in microbial communities in order to develop a better understanding of the biofouling. For the two sites studied, the examination of the front membrane of the first stage and the tail membrane of the second stage of the RO train using 16S rRNA gene-based molecular technique showed that bacteria were similar on both stages and no significant effect of the membrane location within the RO train on the biofilm development could be discerned. However, the comparison of the identified bacteria from membrane samples between the two sites showed that each site is specific, leading to a different composition of microbial communities. The different nutrient concentrations in the RO feed water due to the different biological pre-treatments are one potential explanation for the observed differences in the microbial communities. Seasonal variations also play a major role in the development of microbial communities as shown by the significant differences observed between the communities measured in the samples in winter and summer on the second site. The results did not show similarity between the species identified on the RO membranes and in the feed water. Hence, the relationship of microbial community between the water generated during the pre-treatment process and RO membranes is not obvious. From this study, results showed that there is an actual need to investigate the development of microbial communities on membrane surface in real conditions in order to suggest tailored solutions for biofouling control and removal. © 2013 Elsevier Ltd.

  16. Microbial community analysis of fouled reverse osmosis membranes used in water recycling

    KAUST Repository

    Ayache, C.

    2013-06-01

    Biofouling on RO membranes has major cost implications in water reclamation. In this study membranes and water samples were collected from a RO pilot-plant operated on two sites to study the differences in microbial communities in order to develop a better understanding of the biofouling. For the two sites studied, the examination of the front membrane of the first stage and the tail membrane of the second stage of the RO train using 16S rRNA gene-based molecular technique showed that bacteria were similar on both stages and no significant effect of the membrane location within the RO train on the biofilm development could be discerned. However, the comparison of the identified bacteria from membrane samples between the two sites showed that each site is specific, leading to a different composition of microbial communities. The different nutrient concentrations in the RO feed water due to the different biological pre-treatments are one potential explanation for the observed differences in the microbial communities. Seasonal variations also play a major role in the development of microbial communities as shown by the significant differences observed between the communities measured in the samples in winter and summer on the second site. The results did not show similarity between the species identified on the RO membranes and in the feed water. Hence, the relationship of microbial community between the water generated during the pre-treatment process and RO membranes is not obvious. From this study, results showed that there is an actual need to investigate the development of microbial communities on membrane surface in real conditions in order to suggest tailored solutions for biofouling control and removal. © 2013 Elsevier Ltd.

  17. Removal of Pharmaceutical and Personal Care Products (PPCPs) from Municipal Waste Water with Integrated Membrane Systems, MBR-RO/NF.

    Science.gov (United States)

    Wang, Yonggang; Wang, Xu; Li, Mingwei; Dong, Jing; Sun, Changhong; Chen, Guanyi

    2018-02-05

    This study focuses on the application of combining membrane bioreactor (MBR) treatment with reverse osmosis (RO) or nanofiltration (NF) membrane treatment for removal of pharmaceuticals and personal care products (PPCPs) in municipal wastewater. Twenty-seven PPCPs were measured in real influent with lowest average concentration being trimethoprim (7.12 ng/L) and the highest being caffeine (18.4 ng/L). The results suggest that the MBR system effectively removes the PPCPs with an efficiency of between 41.08% and 95.41%, and that the integrated membrane systems, MBR-RO/NF, can achieve even higher removal rates of above 95% for most of them. The results also suggest that, due to the differences in removal mechanisms of NF/RO membrane, differences of removal rates exist. In this study, the combination of MBR-NF resulted in the removal of 13 compounds to below detection limits and MBR-RO achieved even better results with removal of 20 compounds to below detection limits.

  18. Flight Testing of the Forward Osmosis Bag for Water Recovery on STS-135

    Science.gov (United States)

    Roberts, Michael S.; Soler, Monica; Mortenson, Todd; McCoy, LaShelle; Woodward, Spencer; Levine, Howard G.

    2011-01-01

    The Forward Osmosis Bag (FOB) is a personal water purification device for recovery of potable liquid from almost any non-potable water source. The FOB experiment was flown as a sortie mission on STS-135/ULF7 using flight-certified materials and a design based on the X-Pack(TradeMark) from Hydration Technology Innovations (Albany, OR). The primary objective was to validate the technology for use under microgravity conditions. The FOB utilizes a difference in solute concentration across a selectively permeable membrane to draw water molecules from the non-potable water while rejecting most chemical and all microbial contaminants contained within. Six FOB devices were tested on STS-135 for their ability to produce a potable liquid permeate from a feed solution containing 500 mL potassium chloride (15 g/L) amended with 0.1% methyl blue dye (w:v) tracer against an osmotic gradient created by addition of 60 mL of concentrate containing the osmolytes fructose and glucose, and 0.01% sodium fluorescein (w:v) tracer. Three FOB devices were physically mixed by hand for 2 minutes by a crewmember after loading to augment membrane wetting for comparison with three unmixed FOB devices. Hydraulic flux rate and rejection of salt and dye in microgravity were determined from a 60-mL sample collected by the crew on orbit after 6 hours. Post-flight analysis of samples collected on orbit demonstrated that the Forward Osmosis Bag achieved expected design specifications in microgravity. The hydraulic flux rate of water across the membrane was reduced approximately 50% in microgravity relative to ground controls that generated an average of 50 mL per hour using the same water and osmolyte solutions. The membrane rejected both potassium and chloride at >92% and methyl blue dye at >99.9%. Physical mixing of the FOB during water recovery did not have any significant effect on either flux rate or rejection of solutes from the water solution. The absence of buoyancy-driven convection in

  19. Application of forward osmosis membrane technology for oil sands process-affected water desalination.

    Science.gov (United States)

    Jiang, Yaxin; Liang, Jiaming; Liu, Yang

    2016-01-01

    The extraction process used to obtain bitumen from the oil sands produces large volumes of oil sands process-affected water (OSPW). As a newly emerging desalination technology, forward osmosis (FO) has shown great promise in saving electrical power requirements, increasing water recovery, and minimizing brine discharge. With the support of this funding, a FO system was constructed using a cellulose triacetate FO membrane to test the feasibility of OSPW desalination and contaminant removal. The FO systems were optimized using different types and concentrations of draw solution. The FO system using 4 M NH4HCO3 as a draw solution achieved 85% water recovery from OSPW, and 80 to 100% contaminant rejection for most metals and ions. A water backwash cleaning method was applied to clean the fouled membrane, and the cleaned membrane achieved 77% water recovery, a performance comparable to that of new FO membranes. This suggests that the membrane fouling was reversible. The FO system developed in this project provides a novel and energy efficient strategy to remediate the tailings waters generated by oil sands bitumen extraction and processing.

  20. Sustainable water recovery from oily wastewater via forward osmosis-membrane distillation (FO-MD).

    Science.gov (United States)

    Zhang, Sui; Wang, Peng; Fu, Xiuzhu; Chung, Tai-Shung

    2014-04-01

    This study proposed and investigated a hybrid forward osmosis - membrane distillation (FO-MD) system for sustainable water recovery from oily wastewater by employing lab-fabricated FO and MD hollow fiber membranes. Stable oil-in-water emulsions of different concentrations with small droplet sizes (oil droplets and partial permeation of acetic acid could be achieved. Finally, an integrated FO-MD system was developed to treat the oily wastewater containing petroleum, surfactant, NaCl and acetic acid at 60 °C in the batch mode. The water flux in FO undergoes three-stage decline due to fouling and reduction in osmotic driving force, but is quite stable in MD regardless of salt concentration. Oily wastewater with relatively high salinity could be effectively recovered by the FO-MD hybrid system while maintaining large water flux, at least 90% feed water recovery could be readily attained with only trace amounts of oil and salts, and the draw solution was re-generated for the next rounds of FO-MD run. Interestingly, significant amount of acetic acid was also retained in the permeate for further reuse as a chemical additive during the production of crude oil. The work has demonstrated that not only water but also organic additives in the wastewater could be effectively recovered by FO-MD systems for reuse or other utilizations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Use of water processed by reverse osmosis For vapor generation in tobacco industry

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Klimeck Gouvea

    2012-06-01

    Full Text Available This article presents a study due to the technical use of reverse osmosis to treat the boiler water for steam generation in a plant of tobacco processing in Santa Catarina, Brazil. The monitoring was conducted between the years 2006 to 2008, presenting the results concerning the improvement of water quality with emphasis on environmental and financial gains. Water quality can be observed by the reduction of 90% in silica content and 100% hardness, leading to a reduction of incrustation and corrosion of the system. Moreover, a reduction in the discharges water from the boiler volume reduced the water consumption by approximately 6,000 m3/year and also the consumption of chemicals used in wastewater treatment plant, with a reduction of 32.76 m3/day of effluents to treatment. The reducing of energy with natural gas for water heating replacement was almost 900,000 m3/year (19.45%, because of increased in heat exchange efficiency. The reducing in the CO2 emissions was in order of 1215,65 t/year. Finally, based on the achieved results obtained, can be possible to assume a reducing costs of production as a whole.

  2. CAPSULE REPORT: REVERSE OSMOSIS PROCESS

    Science.gov (United States)

    A failure analysis has been completed for the reverse osmosis (RO) process. The focus was on process failures that result in releases of liquids and vapors to the environment. The report includes the following: 1) A description of RO and coverage of the principles behind the proc...

  3. Evaluating the impacts of membrane type, coating, fouling, chemical properties and water chemistry on reverse osmosis rejection of seven nitrosoalklyamines, including NDMA.

    Science.gov (United States)

    Steinle-Darling, Eva; Zedda, Marco; Plumlee, Megan H; Ridgway, Harry F; Reinhard, Martin

    2007-09-01

    Reverse osmosis (RO) treatment has been found to be effective for a wide range of organics but generally small, polar, uncharged molecules such as N-nitrosodimethylamine (NDMA) can be poorly rejected. The rejection of seven N-nitrosoalkylamines with molecular masses in the range of 78-158Da, including NDMA, N-nitrosodiethylamine (NDEA), N-nitrosomethylethylamine (NMEA), N-nitrosodipropylamine (NDPA), N-nitrosodibutylamine (NDBA), N-nitrosopyrrolidine (NPyr), N-nitrosopiperidine (NPip) by three commercial brackish-water reverse osmosis membranes was studied in flat-sheet cells under cross-flow conditions. The membranes used were ESPA3 (Hydranautics), LFC3 (Hydranautics) and BW-30 (Dow/Filmtec), commonly used in water reuse applications. The effects of varying ionic strength and pH, dip-coating membranes with PEBAX 1657, a hydrophilic polymer, and artificial fouling with alginate on nitrosamine rejection were quantified. Rejection in deionized (DI) water increased with molecular mass from 56 to 70% for NDMA, to 80-91% for NMEA, 89-97% for NPyr, 92-98% for NDEA, and to beyond the detection limits for NPip, NDPA and NDBA. For the nitrosamines with quantifiable transmission, linear correlations (r(2)>0.97) were found between the number of methyl groups and the log(transmission), with factor 0.35 to 0.55 decreases in transmission per added methyl group. A PEBAX coating lowered the ESPA3 rejection of NDMA by 11% but increased the LFC3 and BW30 rejection by 6% and 15%, respectively. Artificially fouling ESPA3 membrane coupons with 170g/m(2) alginate decreased the rejection of NDMA by 18%. A feed concentration of 100mM NaCl decreased rejection of NDMA by 15% and acidifying the DI water feed to pH=3 decreased the rejection by 5%, whereas increasing the pH to 10 did not have a significant (p<0.05) effect.

  4. Rejection of Emerging Organic Contaminants by Nanofiltration and Reverse Osmosis Membranes: Effects of Fouling, Modelling and Water Reuse

    OpenAIRE

    Yangali Quintanilla, V.

    2010-01-01

    The book contains a description of the presence of micropollutants (medicines, hormones, pesticides) in surface water and shows that conventional water treatment poorly removes micropollutants. Nanofiltration and reverse osmosis are more appropriate technologies; however removals can vary depending on the properties of compounds and types of membranes. Thus, quantification of removals is studied by means of multivariate data analysis techniques and more understanding of the separation of micr...

  5. Purifying fluoride-contaminated water by a novel forward osmosis design with enhanced flux under reduced concentration polarization.

    Science.gov (United States)

    Pal, Madhubonti; Chakrabortty, Sankha; Pal, Parimal; Linnanen, Lassi

    2015-08-01

    For purifying fluoride-contaminated water, a new forward osmosis scheme in horizontal flat-sheet cross flow module was designed and investigated. Effects of pressure, cross flow rate, draw solution and alignment of membrane module on separation and flux were studied. Concentration polarization and reverse salt diffusion got significantly reduced in the new hydrodynamic regime. This resulted in less membrane fouling, better solute separation and higher pure water flux than in a conventional module. The entire scheme was completed in two stages-an upstream forward osmosis for separating pure water from contaminated water and a downstream nanofiltration operation for continuous recovery and recycle of draw solute. Synchronization of these two stages of operation resulted in a continuous, steady-state process. From a set of commercial membranes, two polyamide composite membranes were screened out for the upstream and downstream filtrations. A 0.3-M NaCl solution was found to be the best one for forward osmosis draw solution. Potable water with less than 1% residual fluoride could be produced at a high flux of 60-62 L m(-2) h(-1) whereas more than 99% draw solute could be recovered and recycled in the downstream nanofiltration stage from where flux was 62-65 L m(-2) h(-1).

  6. Effect of the scale inhibitor on ion content in reverse osmosis system for seawater desalination

    Science.gov (United States)

    Gao, Yuhua; Liu, Zhenfa; Zhang, Lihui; Li, Haihua

    2017-09-01

    A scale inhibitor was synthesized from polysuccinimide with 2-aminoethanesulfonic acid and aspartic acid. The effect of scale inhibitor on ion content in reverse osmosis system for seawater desalination was studied. The results showed that the ion content of permeate water is lower with the scale inhibitor added in RO system for seawater desalination than without scale inhibitor. On the contrary, the ion content of concentrate water is higher when with scale inhibitor in RO system.

  7. Evaluation of RO modules for the SSP ETC/LSS.

    Science.gov (United States)

    Jasionowski, W. J.; Bambenek, R. A.

    1973-01-01

    During the past eight years the NASA Manned Spacecraft Center has supported the development of an Integrated Water and Waste Management System for use in the Space Station Prototype (SSP) Environmental Thermal Control/Life-Support System (ETC/LSS). This system includes the reverse osmosis (RO) process for recycling wash water and the compression distillation process for recovering useable water from urine, urinal flush water, humidity condensate, commode flush water and the wash water concentrated by RO. This paper summarizes the experimental work performed during the past four years to select the best commercially available RO module for this system and to also define which surfactants and germicides are most compatible with the selected module.

  8. Effect of water temperature on biofouling development in reverse osmosis membrane systems.

    Science.gov (United States)

    Farhat, N M; Vrouwenvelder, J S; Van Loosdrecht, M C M; Bucs, Sz S; Staal, M

    2016-10-15

    Understanding the factors that determine the spatial and temporal biofilm development is a key to formulate effective control strategies in reverse osmosis membrane systems for desalination and wastewater reuse. In this study, biofilm development was investigated at different water temperatures (10, 20, and 30 °C) inside a membrane fouling simulator (MFS) flow cell. The MFS studies were done at the same crossflow velocity with the same type of membrane and spacer materials, and the same feed water type and nutrient concentration, differing only in water temperature. Spatially resolved biofilm parameters such as oxygen decrease rate, biovolume, biofilm spatial distribution, thickness and composition were measured using in-situ imaging techniques. Pressure drop (PD) increase in time was used as a benchmark as to when to stop the experiments. Biofilm measurements were performed daily, and experiments were stopped once the average PD increased to 40 mbar/cm. The results of the biofouling study showed that with increasing feed water temperature (i) the biofilm activity developed faster, (ii) the pressure drop increased faster, while (iii) the biofilm thickness decreased. At an average pressure drop increase of 40 mbar/cm over the MFS for the different feed water temperatures, different biofilm activities, structures, and quantities were found, indicating that diagnosis of biofouling of membranes operated at different or varying (seasonal) feed water temperatures may be challenging. Membrane installations with a high temperature feed water are more susceptible to biofouling than installations fed with low temperature feed water. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Fertiliser drawn forward osmosis process: Pilot-scale desalination of mine impaired water for fertigation

    KAUST Repository

    Phuntsho, Sherub; Kim, Jung Eun; Johir, Mohammad AH; Hong, Seungkwan; Li, Zhenyu; Ghaffour, NorEddine; Leiknes, TorOve; Shon, Ho Kyong

    2016-01-01

    The pilot-scale fertiliser driven forward osmosis (FDFO) and nanofiltration (NF) system was operated in the field for about six months for the desalination of saline groundwater from the coal mining activities. Long-term operation of the FDFO-NF system indicates that simple hydraulic cleaning could effectively restore the water flux with minimal chemical cleaning frequency. No fouling/scaling issues were encountered with the NF post-treatment process. The study indicates that, FDFO-NF desalination system can produce water quality that meets fertigation standard. This study also however shows that, the diffusion of solutes (both feed and draw) through the cellulose triacetate (CTA) FO membrane could be one of the major issues. The FO feed brine failed to meet the effluent discharge standard for NH4+ and SO42+ (reverse diffusion) and their concentrations are expected to further increase at higher feed recovery rates. Low rejection of feed salts (Na+, Cl−) by FO membrane may result in their gradual build-up in the fertiliser draw solution (DS) in a closed FDFO-NF system eventually affecting the final water quality unless it is balanced by adequate bleeding from the system through NF and re-reverse diffusion towards the FO feed brine. Therefore, FO membrane with higher reverse flux selectivity than the CTA-FO membrane used in this study is necessary for the application of the FDFO desalination process.

  10. Membrane distillation for wastewater reverse osmosis concentrate treatment with water reuse potential

    KAUST Repository

    Naidu, Gayathri

    2016-11-29

    Membrane distillation (MD) was evaluated as a treatment option of wastewater reverse osmosis concentrate (WWROC) discharged from wastewater reclamation plants (WRPs). A direct contact MD (DCMD), at obtaining 85% water recovery of WWROC showed only 13–15% flux decline and produced good quality permeate (10–15 µS/cm, 99% ion rejection) at moderate feed temperature of 55 °C. Prevalent calcium carbonate (CaCO3) deposition on the MD membrane occurred in treating WWROC at elevated concentrations. The combination of low salinity and loose CaCO3 adhesion on the membrane did not significantly contribute to DCMD flux decline. Meanwhile, high organic content in WWROC (58–60 mg/L) resulted in a significant membrane hydrophobicity reduction (70% lower water contact angle than virgin membrane) attributed to low molecular weight organic adhesion onto the MD membrane. Granular activated carbon (GAC) pretreatment helped in reducing organic contents of WWROC by 46–50%, and adsorbed a range of hydrophobic and hydrophilic micropollutants. This ensured high quality water production by MD (micropollutants-free) and enhanced its reuse potential. The MD concentrated WWROC was suitable for selective ion precipitation, promising a near zero liquid discharge in WRPs.

  11. Membrane distillation for wastewater reverse osmosis concentrate treatment with water reuse potential

    KAUST Repository

    Naidu, Gayathri; Jeong, Sanghyun; Choi, Youngkwon; Vigneswaran, Saravanamuthu

    2016-01-01

    Membrane distillation (MD) was evaluated as a treatment option of wastewater reverse osmosis concentrate (WWROC) discharged from wastewater reclamation plants (WRPs). A direct contact MD (DCMD), at obtaining 85% water recovery of WWROC showed only 13–15% flux decline and produced good quality permeate (10–15 µS/cm, 99% ion rejection) at moderate feed temperature of 55 °C. Prevalent calcium carbonate (CaCO3) deposition on the MD membrane occurred in treating WWROC at elevated concentrations. The combination of low salinity and loose CaCO3 adhesion on the membrane did not significantly contribute to DCMD flux decline. Meanwhile, high organic content in WWROC (58–60 mg/L) resulted in a significant membrane hydrophobicity reduction (70% lower water contact angle than virgin membrane) attributed to low molecular weight organic adhesion onto the MD membrane. Granular activated carbon (GAC) pretreatment helped in reducing organic contents of WWROC by 46–50%, and adsorbed a range of hydrophobic and hydrophilic micropollutants. This ensured high quality water production by MD (micropollutants-free) and enhanced its reuse potential. The MD concentrated WWROC was suitable for selective ion precipitation, promising a near zero liquid discharge in WRPs.

  12. Subsurface intakes for seawater reverse osmosis facilities: Capacity limitation, water quality improvement, and economics

    KAUST Repository

    Missimer, Thomas M.

    2013-08-01

    The use of subsurface intake systems for seawater reverse osmosis (SWRO) desalination plants significantly improves raw water quality, reduces chemical usage and environmental impacts, decreases the carbon footprint, and reduces cost of treated water to consumers. These intakes include wells (vertical, angle, and radial type) and galleries, which can be located either on the beach or in the seabed. Subsurface intakes act both as intakes and as part of the pretreatment system by providing filtration and active biological treatment of the raw seawater. Recent investigations of the improvement in water quality made by subsurface intakes show lowering of the silt density index by 75 to 90%, removal of nearly all algae, removal of over 90% of bacteria, reduction in the concentrations of TOC and DOC, and virtual elimination of biopolymers and polysaccharides that cause organic biofouling of membranes. Economic analyses show that overall SWRO operating costs can be reduced by 5 to 30% by using subsurface intake systems. Although capital costs can be slightly to significantly higher compared to open-ocean intake system costs, a preliminary life-cycle cost analysis shows significant cost saving over operating periods of 10 to 30. years. © 2013 Elsevier B.V.

  13. Fertiliser drawn forward osmosis process: Pilot-scale desalination of mine impaired water for fertigation

    KAUST Repository

    Phuntsho, Sherub

    2016-02-20

    The pilot-scale fertiliser driven forward osmosis (FDFO) and nanofiltration (NF) system was operated in the field for about six months for the desalination of saline groundwater from the coal mining activities. Long-term operation of the FDFO-NF system indicates that simple hydraulic cleaning could effectively restore the water flux with minimal chemical cleaning frequency. No fouling/scaling issues were encountered with the NF post-treatment process. The study indicates that, FDFO-NF desalination system can produce water quality that meets fertigation standard. This study also however shows that, the diffusion of solutes (both feed and draw) through the cellulose triacetate (CTA) FO membrane could be one of the major issues. The FO feed brine failed to meet the effluent discharge standard for NH4+ and SO42+ (reverse diffusion) and their concentrations are expected to further increase at higher feed recovery rates. Low rejection of feed salts (Na+, Cl−) by FO membrane may result in their gradual build-up in the fertiliser draw solution (DS) in a closed FDFO-NF system eventually affecting the final water quality unless it is balanced by adequate bleeding from the system through NF and re-reverse diffusion towards the FO feed brine. Therefore, FO membrane with higher reverse flux selectivity than the CTA-FO membrane used in this study is necessary for the application of the FDFO desalination process.

  14. Preliminary design of seawater and brackish water reverse osmosis desalination systems driven by low-temperature solar organic Rankine cycles (ORC)

    International Nuclear Information System (INIS)

    Delgado-Torres, Agustin M.; Garcia-Rodriguez, Lourdes

    2010-01-01

    In this paper, the coupling between the low-temperature solar organic Rankine cycle (ORC) and seawater and brackish water reverse osmosis desalination units has been carried out. Four substances have been considered as working fluids of the solar cycle (butane, isopentane, R245fa and R245ca). With these four fluids the volumetric flow of fresh water produced per unit of aperture area of stationary solar collector has been calculated. The former has been made with the optimized direct vapour generation (DVG) configuration and heat transfer fluid (HTF) configuration of the solar ORC. In the first one (DVG), working fluid of the ORC is directly heated inside the absorber of the solar collector. In the second one (HTF), a fluid different than the working fluid of the ORC (water in this paper) is heated without phase change inside the absorber of the solar collector. Once this fluid has been heated it is carried towards a heat exchanger where it is cooled. Thermal energy delivered in this cooling process is transferred to the working fluid of the ORC. Influence of condensation temperature of the ORC and regeneration's process effectiveness over productivity of the system has also been analysed. Finally, parameters of several preliminary designs of the low-temperature solar thermal driven RO desalination are supplied. R245fa is chosen as working fluid of the ORC in these preliminary designs. The information of the proposed preliminary designs can also be used, i.e., for the assessment of the use of thermal energy rejected by the solar cycle. Overall analysis of the efficiency of the solar thermal driven RO desalination technology is given with the results presented in this paper and the results obtained with the medium temperature solar thermal RO desalination system presented by the authors in previous papers. This work has been carried out within the framework of the OSMOSOL and POWERSOL projects.

  15. Preliminary design of seawater and brackish water reverse osmosis desalination systems driven by low-temperature solar organic Rankine cycles (ORC)

    Energy Technology Data Exchange (ETDEWEB)

    Delgado-Torres, Agustin M. [Dpto. Fisica Fundamental y Experimental, Electronica y Sistemas, Escuela Tecnica Superior de Ingenieria Civil e Industrial, Universidad de La Laguna (ULL), Avda. Astrofisico Francisco Sanchez s/n. 38206 La Laguna (Tenerife) (Spain); Garcia-Rodriguez, Lourdes [Dpto. Ingenieria Energetica, Universidad de Sevilla Escuela Tecnica Superior de Ingenieros, Camino de los Descubrimientos, s/n 41092 Sevilla (Spain)

    2010-12-15

    In this paper, the coupling between the low-temperature solar organic Rankine cycle (ORC) and seawater and brackish water reverse osmosis desalination units has been carried out. Four substances have been considered as working fluids of the solar cycle (butane, isopentane, R245fa and R245ca). With these four fluids the volumetric flow of fresh water produced per unit of aperture area of stationary solar collector has been calculated. The former has been made with the optimized direct vapour generation (DVG) configuration and heat transfer fluid (HTF) configuration of the solar ORC. In the first one (DVG), working fluid of the ORC is directly heated inside the absorber of the solar collector. In the second one (HTF), a fluid different than the working fluid of the ORC (water in this paper) is heated without phase change inside the absorber of the solar collector. Once this fluid has been heated it is carried towards a heat exchanger where it is cooled. Thermal energy delivered in this cooling process is transferred to the working fluid of the ORC. Influence of condensation temperature of the ORC and regeneration's process effectiveness over productivity of the system has also been analysed. Finally, parameters of several preliminary designs of the low-temperature solar thermal driven RO desalination are supplied. R245fa is chosen as working fluid of the ORC in these preliminary designs. The information of the proposed preliminary designs can also be used, i.e., for the assessment of the use of thermal energy rejected by the solar cycle. Overall analysis of the efficiency of the solar thermal driven RO desalination technology is given with the results presented in this paper and the results obtained with the medium temperature solar thermal RO desalination system presented by the authors in previous papers. This work has been carried out within the framework of the OSMOSOL and POWERSOL projects. (author)

  16. Preparation and water desalination properties of POSS-polyamide nanocomposite reverse osmosis membranes

    KAUST Repository

    Duan, Jintang

    2015-01-01

    The application of nanotechnology to thin-film nanocomposites (TFN) is a new route to enhance membrane performance in water desalination. Here, the potential of polyhedral oligomeric silsesquioxane (POSS) as the nanofiller in polyamide (PA) reverse osmosis membranes was systematically investigated. Four POSS materials (P-8Phenyl, P-8NH3Cl, P-8NH2 and P-1NH2) were introduced into the selective layer by physical blending or chemical fixation during standard interfacial polymerization. Water flux and NaCl rejection were measured with 2000ppm NaCl solution under 15.5bar pressure, and SEM and TEM images of membrane selective layers were obtained. Membranes prepared without POSS showed water flux of 20.0±0.5L/m2·h and salt rejection of 98.0±0.2%. TFN membranes prepared with 0.4% (w/v) P-8Phenyl in the organic phase showed a 65% increase in water flux compared to the pristine PA membrane while maintaining high salt rejection. The selective layer of this membrane maintained the typical ridge-and-valley structure of aromatic PA. Results with P-8NH3Cl and P-8NH2 added to the organic phase were similar. TFN membranes prepared with monoamine P-1NH2 in the organic phase had poor water flux of 3.2L/m2·h, a smooth and more hydrophobic surface, and a much thicker (~400nm) selective layer. One of the four POSS compounds studied, P-8NH3Cl, is sufficiently soluble in water for incorporation into the selective layer via the aqueous phase. Membranes were prepared with P-8NH3Cl in the aqueous phase at varying reaction time, loading, and additive (triethylamine) concentration. With these parameters optimized, water flux increased to 35.4L/m2·h.

  17. A comparison of ROChem reverse osmosis and spiral wound reverse osmosis membrane modules

    International Nuclear Information System (INIS)

    Siler, J.L.

    1992-01-01

    Testing of the ROChem Disc Tube reg-sign reverse osmosis (RO) module's performance on biologically active feed waters has been completed. Both the ROChem module (using Filmtec standard-rejection seawater membranes) and the Filmtec spiral-wound membrane module (using Filmtec high-rejection seawater membranes) were tested with stimulant solutions containing typical bacteria and metal hydroxide levels found in the F/H Effluent Treatment Facility (ETF) influent. Results indicate that the ROChem module gave superior performance over the spiral-wound module. Water flux losses were reduced by over 30% for water recoveries above 40%

  18. Life cycle cost of a hybrid forward osmosis - low pressure reverse osmosis system for seawater desalination and wastewater recovery.

    Science.gov (United States)

    Valladares Linares, R; Li, Z; Yangali-Quintanilla, V; Ghaffour, N; Amy, G; Leiknes, T; Vrouwenvelder, J S

    2016-01-01

    In recent years, forward osmosis (FO) hybrid membrane systems have been investigated as an alternative to conventional high-pressure membrane processes (i.e. reverse osmosis (RO)) for seawater desalination and wastewater treatment and recovery. Nevertheless, their economic advantage in comparison to conventional processes for seawater desalination and municipal wastewater treatment has not been clearly addressed. This work presents a detailed economic analysis on capital and operational expenses (CAPEX and OPEX) for: i) a hybrid forward osmosis - low-pressure reverse osmosis (FO-LPRO) process, ii) a conventional seawater reverse osmosis (SWRO) desalination process, and iii) a membrane bioreactor - reverse osmosis - advanced oxidation process (MBR-RO-AOP) for wastewater treatment and reuse. The most important variables affecting economic feasibility are obtained through a sensitivity analysis of a hybrid FO-LPRO system. The main parameters taken into account for the life cycle costs are the water quality characteristics (similar feed water and similar water produced), production capacity of 100,000 m(3) d(-1) of potable water, energy consumption, materials, maintenance, operation, RO and FO module costs, and chemicals. Compared to SWRO, the FO-LPRO systems have a 21% higher CAPEX and a 56% lower OPEX due to savings in energy consumption and fouling control. In terms of the total water cost per cubic meter of water produced, the hybrid FO-LPRO desalination system has a 16% cost reduction compared to the benchmark for desalination, mainly SWRO. Compared to the MBR-RO-AOP, the FO-LPRO systems have a 7% lower CAPEX and 9% higher OPEX, resulting in no significant cost reduction per m(3) produced by FO-LPRO. Hybrid FO-LPRO membrane systems are shown to have an economic advantage compared to current available technology for desalination, and comparable costs with a wastewater treatment and recovery system. Based on development on FO membrane modules, packing density, and

  19. Obtaining high quality water by reverse osmosis. A comparison of the appropriate systems to be applied depending on the quality of the input water; Osmosis inversa para obtener agua de alta calidad. Comparacion de propuestas de sistemas de aplicacion en funcion de la calidad del agua de entrada

    Energy Technology Data Exchange (ETDEWEB)

    Pujadas Nino, A.

    2004-07-01

    This article first takes a brief look at the historical development of reverse osmosis systems. It then used several actual examples to compare the water quality that can be obtained using osmosis membranes and ion exchange resin demineralisation systems. It concludes with a number of recommendations regarding the solutions to be adopted in order to obtain water of a specific quality depending on the quality of the available water. (Author) 6 refs.

  20. Energy efficiency of batch and semi-batch (CCRO) reverse osmosis desalination.

    Science.gov (United States)

    Warsinger, David M; Tow, Emily W; Nayar, Kishor G; Maswadeh, Laith A; Lienhard V, John H

    2016-12-01

    As reverse osmosis (RO) desalination capacity increases worldwide, the need to reduce its specific energy consumption becomes more urgent. In addition to the incremental changes attainable with improved components such as membranes and pumps, more significant reduction of energy consumption can be achieved through time-varying RO processes including semi-batch processes such as closed-circuit reverse osmosis (CCRO) and fully-batch processes that have not yet been commercialized or modelled in detail. In this study, numerical models of the energy consumption of batch RO (BRO), CCRO, and the standard continuous RO process are detailed. Two new energy-efficient configurations of batch RO are analyzed. Batch systems use significantly less energy than continuous RO over a wide range of recovery ratios and source water salinities. Relative to continuous RO, models predict that CCRO and batch RO demonstrate up to 37% and 64% energy savings, respectively, for brackish water desalination at high water recovery. For batch RO and CCRO, the primary reductions in energy use stem from atmospheric pressure brine discharge and reduced streamwise variation in driving pressure. Fully-batch systems further reduce energy consumption by not mixing streams of different concentrations, which CCRO does. These results demonstrate that time-varying processes can significantly raise RO energy efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Energy consumption by forward osmosis treatment of landfill leachate for water recovery.

    Science.gov (United States)

    Iskander, Syeed Md; Zou, Shiqiang; Brazil, Brian; Novak, John T; He, Zhen

    2017-05-01

    Forward osmosis (FO) is an alternative approach for treating landfill leachate with potential advantages of reducing leachate volume and recovering high quality water for direct discharge or reuse. However, energy consumption by FO treatment of leachate has not been examined before. Herein, the operational factors such as recirculation rates and draw concentrations were studied for their effects on the quantified energy consumption by an FO system treating actual leachate collected from two different landfills. It was found that the energy consumption increased with a higher recirculation rate and decreased with a higher draw concentration, and higher water recovery tended to reduce energy consumption. The highest energy consumption was 0.276±0.033kWhm -3 with the recirculation rate of 110mLmin -1 and 1-M draw concentration, while the lowest of 0.005±0.000kWhm -3 was obtained with 30mLmin -1 recirculation and 3-M draw concentration. The leachate with lower concentrations of the contaminants had a much lower requirement for energy, benefited from its higher water recovery. Osmotic backwashing appeared to be more effective for removing foulants, but precise understanding of membrane fouling and its controlling methods will need a long-term study. The results of this work have implied that FO treatment of leachate could be energy efficient, especially with the use of a suitable draw solute that can be regenerated in an energy efficient way and/or through combination with other treatment technologies that can reduce contaminant concentrations before FO treatment, which warrants further investigation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Dialysis water treated by reverse osmosis decreases the levels of C-reactive protein in uremic patients

    Directory of Open Access Journals (Sweden)

    F.S. Thomé

    2005-05-01

    Full Text Available Atherosclerosis is a major complication of chronic renal failure. Microinflammation is involved in atherogenesis and is associated with uremia and dialysis. The role of dialysate water contamination in inducing inflammation has been debated. Our aim was to study inflammatory markers in patients on chronic dialysis, before and 3 to 6 months after switching the water purification system from deionization to reverse osmosis. Patients had demographic, clinical and nutritional information collected and blood drawn for determination of albumin, ferritin, C-reactive protein (CRP, interleukin-6, and tumor necrosis factor-alpha in both situations. Acceptable levels of water purity were less than 200 colony-forming units of bacteria and less than 1 ng/ml of endotoxin. Sixteen patients died. They had higher median CRP (26.6 vs 11.2 mg/dl, P = 0.007 and lower median albumin levels (3.1 vs 3.9 g/l, P < 0.05 compared to the 31 survivors. Eight patients were excluded because of obvious inflammatory conditions. From the 23 remaining patients (mean age ± SD: 51.3 ± 13.9 years, 18 had a decrease in CRP after the water treatment system was changed. Overall, median CRP was lower with reverse osmosis than with deionization (13.2 vs 4.5 mg/l, P = 0.022, N = 23. There was no difference in albumin, cytokines, subjective global evaluation, or clinical and biochemical parameters. In conclusion, uremic patients presented a clinically significant reduction in CRP levels when dialysate water purification system switched from deionization to reverse osmosis. It is possible that better water treatments induce less inflammation and eventually less atherosclerosis in hemodialysis patients.

  3. Forward osmosis membrane modular configurations for osmotic dilution of seawater by forward osmosis and reverse osmosis hybrid system.

    Science.gov (United States)

    Kim, Jung Eun; Phuntsho, Sherub; Ali, Syed Muztuza; Choi, Joon Young; Shon, Ho Kyong

    2018-01-01

    This study evaluates various options for full-scale modular configuration of forward osmosis (FO) process for osmotic dilution of seawater using wastewater for simultaneous desalination and water reuse through FO-reverse osmosis (RO) hybrid system. Empirical relationship obtained from one FO membrane element operation was used to simulate the operational performances of different FO module configurations. The main limiting criteria for module operation is to always maintain the feed pressure higher than the draw pressure throughout the housing module for safe operation without affecting membrane integrity. Experimental studies under the conditions tested in this study show that a single membrane housing cannot accommodate more than four elements as the draw pressure exceeds the feed pressure. This then indicates that a single stage housing with eight elements is not likely to be practical for safe FO operation. Hence, six different FO modular configurations were proposed and simulated. A two-stage FO configuration with multiple housings (in parallel) in the second stage using same or larger spacer thickness reduces draw pressure build-up as the draw flow rates are reduced to half in the second stage thereby allowing more than four elements in the second stage housing. The loss of feed pressure (pressure drop) and osmotic driving force in the second stage are compensated by operating under the pressure assisted osmosis (PAO) mode, which helps enhance permeate flux and maintains positive pressure differences between the feed and draw chamber. The PAO energy penalty is compensated by enhanced permeate throughput, reduced membrane area, and plant footprint. The contribution of FO/PAO to total energy consumption was not significant compared to post RO desalination (90%) indicating that the proposed two-stage FO modular configuration is one way of making the FO full-scale operation practical for FO-RO hybrid system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Tight ceramic UF membrane as RO pre-treatment: The role of electrostatic interactions on phosphate rejection

    NARCIS (Netherlands)

    Shang, R.; Verliefde, A.R.D.; Hu, J.; Zeng, Z; Lu, L.; Lu, L.; Kemperman, Antonius J.B.; Deng, H.; Nijmeijer, Dorothea C.; Heijman, S.G.J.; Rietveld, L.C.

    2014-01-01

    Phosphate limitation has been reported as an effective approach to inhibit biofouling in reverse osmosis (RO) systems for water purification. The rejection of dissolved phosphate by negatively charged TiO2 tight ultrafiltration (UF) membranes (1 kDa and 3 kDa) was observed. These membranes can

  5. Water Diffusion Mechanism in Carbon Nanotube and Polyamide Nanocomposite Reverse Osmosis Membranes: A Possible Percolation-Hopping Mechanism

    Science.gov (United States)

    Araki, Takumi; Cruz-Silva, Rodolfo; Tejima, Syogo; Ortiz-Medina, Josue; Morelos-Gomez, Aaron; Takeuchi, Kenji; Hayashi, Takuya; Terrones, Mauricio; Endo, Morinobu

    2018-02-01

    This paper is a contribution to the Physical Review Applied collection in memory of Mildred S. Dresselhaus. The mechanism of water diffusion across reverse osmosis nanocomposite membranes made of carbon nanotubes (CNTs) and aromatic polyamide is not completely understood despite its high potential for desalination applications. While most of the groups have proposed that superflow inside the CNT might positively impact the water flow across membranes, here we show theoretical evidence that this is not likely the case in composite membranes because CNTs are usually oriented parallel to the membrane surface, not to mention that sometimes the nanotube cores are occluded. Instead, we propose an oriented diffusion mechanism that explains the high water permeation by decreasing the diffusion path of water molecules across the membranes, even in the presence of CNTs that behave as impermeable objects. Finally, we provide a comprehensive description of the molecular dynamics occurring in water desalination membranes by considering the bond polarizability caused by dynamic charge transfer and explore the use of molecular-dynamics-derived stochastic diffusion simulations. The proposed water diffusion mechanism offers an alternative and most likely explanation for the high permeation phenomena observed in CNTs and PA nanocomposite membranes, and its understanding can be helpful to design the next generation of reverse osmosis desalination membranes.

  6. Open-source CFD model for optimization of forward osmosis and reverse osmosis membrane modules

    DEFF Research Database (Denmark)

    Gruber, Mathias Felix; Aslak, Ulf; Hélix-Nielsen, Claus

    2016-01-01

    Osmotic membrane separation processes are based on using semi-permeable membranes to remove solutes from a given feed solution. This can happen either as Reverse Osmosis (RO) where a hydraulic pressure is applied to drive separation across the membrane, or as Forward Osmosis (FO) where osmotic...

  7. Application of Forward Osmosis Membrane in a Sequential Batch Reactor for Water Reuse

    KAUST Repository

    Li, Qingyu

    2011-07-01

    Forward osmosis (FO) is a novel membrane process that potentially can be used as an energy-saving alternative to conventional membrane processes. The objective of this study is to investigate the performance of a FO membrane to draw water from wastewater using seawater as draw solution. A study on a novel osmotic sequential batch reactor (OsSBR) was explored. In this system, a plate and frame FO cell including two flat-sheet FO membranes was submerged in a bioreactor treating the wastewater. We found it feasible to treat the wastewater by the OsSBR process. The DOC removal rate was 98.55%. Total nitrogen removal was 62.4% with nitrate, nitrite and ammonium removals of 58.4%, 96.2% and 88.4% respectively. Phosphate removal was almost 100%. In this OsSBR system, the 15-hour average flux for a virgin membrane with air scouring is 3.103 LMH. After operation of 3 months, the average flux of a fouled membrane is 2.390 LMH with air scouring (23% flux decline). Air scouring can help to remove the loose foulants on the active layer, thus helping to maintain the flux. Cleaning of the FO membrane fouled in the active layer was probably not effective under the conditions of immersing the membrane in the bioreactor. LC-OCD results show that the FO membrane has a very good performance in rejecting biopolymers, humics and building blocks, but a limited ability in rejecting low molecular weight neutrals.

  8. Water reclamation from emulsified oily wastewater via effective forward osmosis hollow fiber membranes under the PRO mode.

    Science.gov (United States)

    Han, Gang; de Wit, Jos S; Chung, Tai-Shung

    2015-09-15

    By using a novel hydrophilic cellulose acetate butyrate (CAB) as the membrane material for the hollow fiber substrate and modifying its outer surface by polydopamine (PDA) coating and inner surface by interfacial polymerization, we have demonstrated that the thin-film composite (TFC) membranes can be effectively used for sustainable water reclamation from emulsified oil/water streams via forward osmosis (FO) under the pressure retarded osmosis (PRO) mode. The newly developed TFC-FO hollow fiber membrane shows characteristics of high water flux, outstanding salt and oil rejection, and low fouling propensity. Under the PRO mode, the newly developed TFC-FO membrane exhibits a water flux of 37.1 L m(-2) h(-1) with an oil rejection of 99.9% using a 2000 ppm soybean oil/water emulsion as the feed and 1 M NaCl as the draw solution. Remarkable anti-fouling behaviors have also been observed. Under the PRO mode, the water flux decline is only 10% of the initial value even after a 12 h test for oil/water separation. The water flux of the fouled membrane can be effectively restored to 97% of the original value by water rinses on the fiber outer surface without using any chemicals. Furthermore, the flux declines are only 25% and 52% when the water recovery of a 2000 ppm soybean oil/water emulsion and a 2000 ppm petroleum oil/water emulsion containing 0.04 M NaCl reaches 82%, respectively. This study may not only provide insightful guidelines for the fabrication of effective TFC-FO membranes with high performance and low fouling behaviors for oily wastewater under the PRO mode but also add an alternative perspective to the design of new materials for water purification purposes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Produced Water Treatment Using the Switchable Polarity Solvent Forward Osmosis (SPS FO) Desalination Process: Preliminary Engineering Design Basis

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, Daniel; Adhikari, Birendra; Orme, Christopher; Wilson, Aaron

    2016-05-01

    Switchable Polarity Solvent Forward Osmosis (SPS FO) is a semi-permeable membrane-based water treatment technology. INL is currently advancing SPS FO technology such that a prototype unit can be designed and demonstrated for the purification of produced water from oil and gas production operations. The SPS FO prototype unit will used the thermal energy in the produced water as a source of process heat, thereby reducing the external process energy demands. Treatment of the produced water stream will reduce the volume of saline wastewater requiring disposal via injection, an activity that is correlated with undesirable seismic events, as well as generate a purified product water stream with potential beneficial uses. This paper summarizes experimental data that has been collected in support of the SPS FO scale-up effort, and describes how this data will be used in the sizing of SPS FO process equipment. An estimate of produced water treatment costs using the SPS FO process is also provided.

  10. Coupling of RO-MSF hybrid desalination plants with nuclear reactors

    International Nuclear Information System (INIS)

    Al-Sulaiman, Khalil; Al-Mutaz, Ibrahim S.

    1999-01-01

    Full text.Reverse osmosis (RO) and multistage flash (MSF) desalination are the most widely commercial available processes. MSF utilizes stream in the brine heater as a primary source of energy. RO is derived mainly by electricity that pumps the feed water against the mambranes. Steam and electricity and be produced easily by nuclear reactors. Nuclear reactors may be coupled with deslination plants (MSF, RO or combined (hybrid) RO/MSF configuration). This integrated plant will be capable of producing power and water at reasonable cost. The capital and operating cost will be reduced and the excess power can be efficiently utilized. Maintenance and operating cost will drop significantly. In this paper, a techno-economic study of hybrid reverses osmosis /multistage flash desalination will be carried. The proposed configuration (hybrid RO/MSF) coupled with nuclear reactor is considered the most appropriate candidate system for the application of dual-purpose nuclear desalination plants. the design parameters for such a desalination hybrid system will be the applied pressure and recovery for reverse osmosis plant and the number of stages and the heat transfer areas for multistage flash plant

  11. Simultaneous Hydrogen Sulphide and Carbon Dioxide Removal from Biogas by Water-Swollen Reverse Osmosis Membrane

    Czech Academy of Sciences Publication Activity Database

    Dolejš, Petr; Poštulka, Václav; Sedláková, Zuzana; Jandová, Věra; Vejražka, Jiří; Esposito, E.; Jansen, J.C.; Izák, Pavel

    2014-01-01

    Roč. 131, JUN 27 (2014), s. 108-116 ISSN 1383-5866 R&D Projects: GA ČR GAP106/10/1194; GA ČR GA14-12695S; GA TA ČR TE01020080; GA MŠk LH14006; GA MŠk(CZ) 7C11009; GA MŠk(CZ) LD13018 Grant - others:RFCS(XE) RFCRCT-2010-00009; PONRC(IT) PON01_01840 Institutional support: RVO:67985858 Keywords : agro-biogas upgrading * biomethane * water vapour Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.091, year: 2014

  12. Coupling reverse osmosis with electrodialysis to isolate natural organic matter from fresh waters

    Science.gov (United States)

    This study was undertaken to solve the problem of removal of sulfate and silica from solutions of natural organic matter (NOM) that have been pre-concentrated by reverse osmosis. The goal is the development of a method by which NOM can be concentrated and desalted to obtain a low...

  13. Environmental and economic impacts of fertilizer drawn forward osmosis and nanofiltration hybrid system

    KAUST Repository

    Kim, Jung Eun; Phuntsho, Sherub; Chekli, Laura; Hong, Seungkwan; Ghaffour, NorEddine; Leiknes, TorOve; Choi, Joon Yong; Shon, Ho Kyong

    2017-01-01

    Environmental and economic impacts of the fertilizer drawn forward osmosis (FDFO) and nanofiltration (NF) hybrid system were conducted and compared with conventional reverse osmosis (RO) hybrid scenarios using microfiltration (MF) or ultrafiltration

  14. Fuzzy logic: applications to the pretreatment of brackish feed water in reverse osmosis treatment plants; Logica difusa: aplicaciones al pretratamiento del agua salobre de elimentacion de plantas desalladoras por osmosis inversa

    Energy Technology Data Exchange (ETDEWEB)

    Pluss Contino, J.; Simon Ruiz, J. L.; Hernandez, A.; Menendez Martinez, A.; Yaglian Steiner, E.; Menendez Fernandez, A.; Marcelo Cano, F.

    2004-07-01

    Frequently physical and chemical alteration that can suffer feed water composition and membranes behaviour of reverse osmosis desalination plants (RODP), define a vague nature system from the point of view of decision make process. In this work, we proposes the utilization of the approximate reasoning associated with the fuzzy logic, as an alternative to approach this problem and to make possible early corrective actions, that is, to do a proactive maintenance with Condition-based maintenance (CBM) technology. (Author) 21 refs.

  15. Using UCST ionic liquid as a draw solute in forward osmosis to treat high-salinity water

    KAUST Repository

    Zhong, Yujiang

    2015-12-09

    The concept of using a thermo-responsive ionic liquid (IL) with an upper critical solution temperature (UCST) as a draw solute in forward osmosis (FO) was successfully demonstrated here experimentally. A 3.2 M solution of protonated betaine bis(trifluoromethylsulfonyl)imide ([Hbet][Tf2N]) was obtained by heating and maintaining the temperature above 56°C. This solution successfully drew water from high-salinity water up to 3.0 M through FO. When the IL solution cooled to room temperature, it spontaneously separated into a water-rich phase and an IL-rich phase: the water-rich phase was the produced water that contained a low IL concentration, and the IL-rich phase could be used directly as the draw solution in the next cycle of the FO process. The thermal stability, thermal-responsive solubility and UV-vis absorption spectra of the IL were also studied in detail.

  16. Reverse osmosis plant maintenance and efficacy in chronic kidney disease endemic region in Sri Lanka.

    Science.gov (United States)

    Jayasumana, Channa; Ranasinghe, Omesh; Ranasinghe, Sachini; Siriwardhana, Imalka; Gunatilake, Sarath; Siribaddana, Sisira

    2016-11-01

    Chronic Interstitial Nephritis in Agricultural Communities (CINAC) causes major morbidity and mortality for farmers in North-Central province (NCP) of Sri Lanka. To prevent the CINAC, reverse osmosis (RO) plants are established to purify the water and reduce the exposure to possible nephrotoxins through drinking water. We assessed RO plant maintenance and efficacy in NCP. We have interviewed 10 RO plant operators on plant establishment, maintenance, usage and funding. We also measured total dissolved solids (TDS in ppm) to assess the efficacy of the RO process. Most RO plants were operated by community-based organizations. They provide clean and sustainable water source for many in the NCP for a nominal fee, which tends to be variable. The RO plant operators carry out RO plant maintenance. However, maintenance procedures and quality management practices tend to vary from an operator to another. RO process itself has the ability to lower the TDS of the water. On average, RO process reduces the TDS to 29 ppm. The RO process reduces the impurities in water available to many individuals within CINAC endemic regions. However, there variation in maintenance, quality management, and day-to-day care between operators can be a cause for concern. This variability can affect the quality of water produced by RO plant, its maintenance cost and lifespan. Thus, uniform regulation and training is needed to reduce cost of maintenance and increase the efficacy of RO plants.

  17. Teaching Mass Transfer and Filtration Using Crossflow Reverse Osmosis and Nanofiltration: An Experiment for the Undergraduate Unit Operations Lab

    Science.gov (United States)

    Anastasio, Daniel; McCutcheon, Jeffrey

    2012-01-01

    A crossflow reverse osmosis (RO) system was built for a senior-level chemical engineering unit operations laboratory course. Intended to teach students mass transfer fundamentals related to membrane separations, students tested several commercial desalination membranes, measuring water flux and salt rejections at various pressures, flow rates, and…

  18. Integrating Microbial Electrochemical Technology with Forward Osmosis and Membrane Bioreactors: Low-Energy Wastewater Treatment, Energy Recovery and Water Reuse

    KAUST Repository

    Werner, Craig M.

    2014-06-01

    Wastewater treatment is energy intensive, with modern wastewater treatment processes consuming 0.6 kWh/m3 of water treated, half of which is required for aeration. Considering that wastewater contains approximately 2 kWh/m3 of energy and represents a reliable alternative water resource, capturing part of this energy and reclaiming the water would offset or even eliminate energy requirements for wastewater treatment and provide a means to augment traditional water supplies. Microbial electrochemical technology is a novel technology platform that uses bacteria capable of producing an electric current outside of the cell to recover energy from wastewater. These bacteria do not require oxygen to respire but instead use an insoluble electrode as their terminal electron acceptor. Two types of microbial electrochemical technologies were investigated in this dissertation: 1) a microbial fuel cell that produces electricity; and 2) a microbial electrolysis cell that produces hydrogen with the addition of external power. On their own, microbial electrochemical technologies do not achieve sufficiently high treatment levels. Innovative approaches that integrate microbial electrochemical technologies with emerging and established membrane-based treatment processes may improve the overall extent of wastewater treatment and reclaim treated water. Forward osmosis is an emerging low-energy membrane-based technology for seawater desalination. In forward osmosis water is transported across a semipermeable membrane driven by an osmotic gradient. The microbial osmotic fuel cell described in this dissertation integrates a microbial fuel cell with forward osmosis to achieve wastewater treatment, energy recovery and partial desalination. This system required no aeration and generated more power than conventional microbial fuel cells using ion exchange membranes by minimizing electrochemical losses. Membrane bioreactors incorporate semipermeable membranes within a biological wastewater

  19. Biofouling of reverse osmosis membranes used in river water purification for drinking purposes: analysis of microbial populations.

    Science.gov (United States)

    Chiellini, Carolina; Iannelli, Renato; Modeo, Letizia; Bianchi, Veronica; Petroni, Giulio

    2012-01-01

    Biofouling in water treatment processes represents one of the most frequent causes of plant performance decline. Investigation of clogged membranes (reverse osmosis membranes, microfiltration membranes and ultrafiltration membranes) is generally performed on fresh membranes. In the present study, a multidisciplinary autopsy of a reverse osmosis membrane (ROM) was conducted. The membrane, which was used in sulfate-rich river water purification for drinking purposes, had become inoperative after 6 months because of biofouling and was later stored for 18 months in dry conditions before analysis. SSU rRNA gene library construction, clone sequencing, T-RFLP, light microscope, and scanning electron microscope (SEM) observations were used to identify the microorganisms present on the membrane and possibly responsible for biofouling at the time of removal. The microorganisms were mainly represented by bacteria belonging to the phylum Actinobacteria and by a single protozoan species belonging to the Lobosea group. The microbiological analysis was interpreted in the context of the treatment plant operations to hypothesize as to the possible mechanisms used by microorganisms to enter the plant and colonize the ROM surface.

  20. A study of reverse osmosis applicability to light water reactor radwaste processing. Technical report

    International Nuclear Information System (INIS)

    Markind, J.; Van Tran, T.

    1979-04-01

    The use of membrane technology has demonstrated significant process potential in nuclear radioactive waste applications. Reverse osmosis and ultrafiltration can provide filtration capability without the need of filter aids, minimize the requirements of chemical regeneration and/or disposal of expensive resins and can preconcentrate wastes without requiring major process equipment with large auxiliary heat supplies. Because of these capabilities, a study was undertaken to review, evaluate and document the existing experience, both nuclear and appropriate non-nuclear, of the membrane industry as it applies to the processing of reactor radwaste by membrane technology and, in particular, reverse osmosis and ultrafiltration. Relevant information was collected from both the literature and extensive communications with users and suppliers of membrane equipment. The systems reviewed ranged from experimental laboratory units to full scale process units

  1. Nanofiltration in Transforming Surface Water into Healthy Water: Comparison with Reverse Osmosis

    Directory of Open Access Journals (Sweden)

    L. D. Naidu

    2015-01-01

    Full Text Available The natural surface water, especially available through rivers, is the main source of healthy water for the living beings throughout the world from ancient days as it consists of all essential minerals. With the advent of industrialization, gradually even the most prominent rivers have been polluted in all parts of the world. Although there are lots of technologies, nanofiltration (NF has been chosen to transform river water into healthy water due to its unique advantages of retaining optimum TDS (with essential minerals required for human body, consuming of lower energy, and no usage of any chemicals. The prominent parameters of surface water and macro/microminerals of treated water have been analyzed. It is shown that NF is better in producing healthy water with high flux by consuming low energy.

  2. Fresh water production from municipal waste water with RO membrane technology and its application for agriculture and industry in arid area

    International Nuclear Information System (INIS)

    Yokoyama, F

    2015-01-01

    One of the biggest problems of the 21st century is the global water shortage. Therefore it is difficult to increase the quantity of conventional water resources such as surface water and groundwater for agriculture and industry in arid area. Technical advancement in water treatment membrane technology including RO membrane has been remarkable especially in recent years. As the pore size of RO membrane is less than one nanometer, it is possible to produce the fresh water, which satisfies the drinking water quality standards, with utilizing RO membrane. In this report a new fresh water resource from municipal waste water is studied to apply to the plant factory which is the water saving type agriculture and industry in arid area

  3. Fertilizer drawn forward osmosis process for sustainable water reuse to grow hydroponic lettuce using commercial nutrient solution

    KAUST Repository

    Chekli, Laura

    2017-03-10

    This study investigated the sustainable reuse of wastewater using fertilizer drawn forward osmosis (FDFO) process through osmotic dilution of commercial nutrient solution for hydroponics, a widely used technique for growing plants without soil. Results from the bench-scale experiments showed that the commercial hydroponic nutrient solution (i.e. solution containing water and essential nutrients) exhibited similar performance (i.e., water flux and reverse salt flux) to other inorganic draw solutions when treating synthetic wastewater. The use of hydroponic solution is highly advantageous since it provides all the required macro- (i.e., N, P and K) and micronutrients (i.e., Ca, Mg, S, Mn, B, Zn and Mo) in a single balanced solution and can therefore be used directly after dilution without the need to add any elements. After long-term operation (i.e. up to 75% water recovery), different physical cleaning methods were tested and results showed that hydraulic flushing can effectively restore up to 75% of the initial water flux while osmotic backwashing was able to restore the initial water flux by more than 95%; illustrating the low-fouling potential of the FDFO process. Pilot-scale studies demonstrated that the FDFO process is able to produce the required nutrient concentration and final water quality (i.e., pH and conductivity) suitable for hydroponic applications. Coupling FDFO with pressure assisted osmosis (PAO) in the later stages could help in saving operational costs (i.e., energy and membrane replacement costs). Finally, the test application of nutrient solution produced by the pilot FDFO process to hydroponic lettuce showed similar growth pattern as the control without any signs of nutrient deficiency.

  4. Spontaneous direct and reverse osmosis

    International Nuclear Information System (INIS)

    Valitov, N.Kh.

    1996-01-01

    It has been ascertained experimentally that in the course of separation of CsCl, KCl, NaCl aqueous solutions by semi-permeable membrane from distilled water the direct and then reverse osmosis are observed. The same sequence is observed in case of separation of CsCl aqueous solutions from NaCl of different concentrations. The reason for the direct and reverse osmosis has been explained. 5 refs.; 3 figs. 1 tab

  5. Inorganic fouling mitigation by salinity cycling in batch reverse osmosis

    OpenAIRE

    Maswadeh, Laith A.; Warsinger, David Elan Martin; Tow, Emily W.; Connors, Grace B.; Swaminathan, Jaichander; Lienhard, John H

    2018-01-01

    Enhanced fouling resistance has been observed in recent variants of reverse osmosis (RO) desalination which use time-varying batch or semi-batch processes, such as closed-circuit RO (CCRO) and pulse flow RO (PFRO). However, the mechanisms of batch processes' fouling resistance are not well-understood, and models have not been developed for prediction of their fouling performance. Here, a framework for predicting reverse osmosis fouling is developed by comparing the fluid residence time in bat...

  6. Successful cleaning concept for Germany's biggest reverse osmosis plant; Ein erfolgreiches Reinigungskonzept fuer die groesste Umkehrosmoseanlage Deutschlands

    Energy Technology Data Exchange (ETDEWEB)

    Kempen, Hermann [Kurita Europe GmbH, Viersen (Germany); Zierau, Ronald [Zellstoff-Stendal GmbH, Arneburg (Germany)

    2012-07-01

    During the last years, new developments for membrane material and also for treatment chemicals have resulted in higher efficiency and reliability of reverse osmosis (RO) plants. Nevertheless, especially RO plants receiving raw water from surface waters with open intake or from waste water streams are facing problems with fouling on membranes during operation. In such cases, the efficient cleaning of membranes is mandatory to ensure long-term supply of permeate in high quality and sufficient quantity. New cleaning concepts with proprietary cleaning products are gaining in importance. The successful application of such a cleaning concept at Germany's biggest RO plant is described in this paper. (orig.)

  7. Applying the coagulation and reverse osmosis for water recovery from evaporative water

    Directory of Open Access Journals (Sweden)

    Michel Magdalena M.

    2014-12-01

    Full Text Available Zastosowanie koagulacji i odwróconej osmozy do odzysku wody z wód wyparnych. Wody wyparne z zatężania gęstwy drożdżowej stanowią potencjalny surowiec do odzysku wody. Charakteryzują się niskim odczynem (pH 4.6-6.3, podwyższoną mętnością (3.65-13.7 NTU i dużą zawartością ogólnego węgla organicznego (356-754 mg/L. Badano ich oczyszczanie w procesie koagulacji objętościowej, stosując NaOH oraz koagulant PIX 111. Obniżono mętność wody do wartości poniżej 1 NTU, jednak koagulacja nie pozwalała na usunięcie związków organicznych. Koagulacja przebiegała efektywnie w 20 i 40°C. Oczyszczanie wstępne nadawy do RO obejmowało alkalizację, koagulację, sedymentację i filtrację dokładną (wariant I oraz filtrację dokładną (wariant II jako blank. W wariancie I otrzymano nadawę o lepszych właściwościach. Filtracja membranowa pozwoliła na skuteczne odsolenie wód wyparnych, uzyskano 98 i 73% retencję przewodności w zależności od sposobu przygotowania nadawy. Związki organiczne były usuwane z mniejszą efektywnością, odpowiednio 94 i 84%.

  8. IMPACT ON WATER DISTRIBUTION SYSTEM BIOFILM DENSITIES FROM REVERSE OSMOSIS MEMBRANE TREATMENT OF SUPPLY WATER

    Science.gov (United States)

    The quality of potable water is such that the concentration of nutrients available for growth of microorganisms within distribution systems is limited. In such systems carbon is often the growth limiting nutrient. Research conducted in the Netherlands has indicated that low level...

  9. Solution-diffusion with defects model for pressure-assisted forward osmosis

    KAUST Repository

    Duan, Jintang

    2014-11-01

    An osmosis transport model is presented that combines the standard internal and external concentration polarization equations in the forward osmosis (FO) field with the selective layer transport equations first proposed by Sherwood in 1967. The Sherwood model describes water flux as the sum of a solute-selective, diffusive component driven by the sum of osmotic pressure and hydraulic pressure differences, and a nonselective, convective component driven by hydraulic pressure difference only. This solution-diffusion with defects (SDWD) model and the solution-diffusion (SD) model were compared against data collected using polyamide thin-film-composite (PA-TFC) and integrally-skinned asymmetric cellulose triacetate (CTA) membranes, evaluated in various configurations. When tested with pure water on the porous support side and 1.5. M (π=72.7. bar) sodium chloride solution on the selective layer side, applying 1.25. bar of hydraulic pressure to the porous support side increased water flux by an order of magnitude for PA-TFC membranes, but had negligible effect on CTA membrane flux. These large flux variations can be explained by the SDWD model, but not the SD model. To confirm the existence of defects, a PA-TFC membrane was coated with a uniform, highly water-permeable, nonselective polymer. After coating to block convection through defects, the influence of hydraulic pressure on water flux through this membrane essentially disappeared. Water flux through these defects is low (<1% of total water flux for PA-TFC membranes) and of little consequence in practical FO or reverse osmosis (RO) applications. But in pressure-assisted forward osmosis (PAFO) or pressure-retarded osmosis (PRO), convective transport through defects affects the solute concentration difference across the membrane selective layer, increasing or decreasing water flux through defect-free regions. The presence of defects may explain why membrane power density in PRO is lower than that predicted based on

  10. Effects of surface coating process conditions on the water permeation and salt rejection properties of composite polyamide reverse osmosis membranes

    KAUST Repository

    Louie, Jennifer Sarah

    2011-02-01

    The application of polymer surface coatings to improve the fouling resistance of reverse osmosis membranes tends to increase flow resistance across the membrane. This paper presents a systematic analysis on how membrane properties and performance are impacted by the coating process steps, and investigates how such effects could contribute to lower water flux. On one hand, simply pre-soaking dry aromatic polyamide composite membranes in aliphatic alcohols results in a significant increase in water flux, which is attributed to wetting of pores in the selective polyamide layer and to changes in the polymer structure. This flux increase was not readily reversible, based on a 300-h water permeation test. Conversely, drying a wetted membrane led to a decrease in water flux, which we hypothesize is caused by increased interchain hydrogen-bonding in the selective layer. This drop in water flux was not permanent; higher flux was observed if the same wetted/dried membrane was then re-soaked in ethanol prior to the water permeation experiment. An ethanol pre-soaking step also increased water flux of a PEBAX-coated membrane by nearly 70%. In contrast to the reduction in water flux caused by the specific treatment sequence of ethanol-swelling followed by drying, this same sequence actually increased gas transport. The eight- to ten-fold increase in Knudsen diffusion-based gas permeance after this pre-treatment was attributed to an increase in the number or size of membrane defects. © 2010 Elsevier B.V.

  11. Performance of Potassium Bicarbonate and Calcium Chloride Draw Solutions for Desalination of Saline Water Using Forward Osmosis

    Directory of Open Access Journals (Sweden)

    M. Nematzadeh

    2015-01-01

    Full Text Available Forward osmosis (FO has recently drawn attention as a promising membrane based method for seawater and brackish water desalination. In this study, we focus on the use of calciun chloride (CaCl2 and potassium bicarbonate (KHCO3 as inorganic salt draw solution candidates due to their appropriate performance in water flux and reverse salt diffusion as well as reasonable cost. The experiments were carried at 25 °C and cross-flow rate of 3 L min−1.  At the same osmotic pressure, the water flux of CaCl2 draw solution tested against deionized feed water, showed 20% higher permeation than KHCO3, which it was attributed to the lower internal concentration polarization (ICP. The reverse diffusion of CaCl2 was found higher than KHCO3 solution which it would be related to the smaller ionic size and the higher permeation of this salt through the membrane. The water flux for both draw solutions against 0.33 M NaCl feed solution was about 2.8 times lower than deionized feed water because of ICP. Higher concentrations of draw solution is required for increasing the water permeation from saline water feed towards the draw side.

  12. Forward Osmosis in Wastewater Treatment Processes.

    Science.gov (United States)

    Korenak, Jasmina; Basu, Subhankar; Balakrishnan, Malini; Hélix-Nielsen, Claus; Petrinic, Irena

    2017-01-01

    In recent years, membrane technology has been widely used in wastewater treatment and water purification. Membrane technology is simple to operate and produces very high quality water for human consumption and industrial purposes. One of the promising technologies for water and wastewater treatment is the application of forward osmosis. Essentially, forward osmosis is a process in which water is driven through a semipermeable membrane from a feed solution to a draw solution due to the osmotic pressure gradient across the membrane. The immediate advantage over existing pressure driven membrane technologies is that the forward osmosis process per se eliminates the need for operation with high hydraulic pressure and forward osmosis has low fouling tendency. Hence, it provides an opportunity for saving energy and membrane replacement cost. However, there are many limitations that still need to be addressed. Here we briefly review some of the applications within water purification and new developments in forward osmosis membrane fabrication.

  13. High-speed broadband elastic actuator in water using induced-charge electro-osmosis with a skew structure

    Science.gov (United States)

    Sugioka, Hideyuki; Nakano, Naoki

    2018-01-01

    An artificial cilium using ac electro-osmosis (ACEO) is attractive because of its large potentiality for innovative microfluidic applications. However, the ACEO cilium has not been probed experimentally and has a shortcoming that the working frequency range is very narrow. Thus, we here propose an ACEO elastic actuator having a skew structure that broadens a working frequency range and experimentally demonstrate that the elastic actuator in water can be driven with a high-speed (˜10 Hz) and a wide frequency range (˜0.1 to ˜10 kHz). Moreover, we propose a simple self-consistent model that explains the broadband characteristic due to the skew structure with other characteristics. By comparing the theoretical results with the experimental results, we find that they agree fairly well. We believe that our ACEO elastic actuator will play an important role in microfluidics in the future.

  14. High-speed broadband elastic actuator in water using induced-charge electro-osmosis with a skew structure.

    Science.gov (United States)

    Sugioka, Hideyuki; Nakano, Naoki

    2018-01-01

    An artificial cilium using ac electro-osmosis (ACEO) is attractive because of its large potentiality for innovative microfluidic applications. However, the ACEO cilium has not been probed experimentally and has a shortcoming that the working frequency range is very narrow. Thus, we here propose an ACEO elastic actuator having a skew structure that broadens a working frequency range and experimentally demonstrate that the elastic actuator in water can be driven with a high-speed (∼10 Hz) and a wide frequency range (∼0.1 to ∼10 kHz). Moreover, we propose a simple self-consistent model that explains the broadband characteristic due to the skew structure with other characteristics. By comparing the theoretical results with the experimental results, we find that they agree fairly well. We believe that our ACEO elastic actuator will play an important role in microfluidics in the future.

  15. Application of a nanofibrous composite membrane to the fertilizer-driven forward osmosis process for irrigation water use.

    Science.gov (United States)

    An, Hee-Kyung; Lee, Chang-Gu; Park, Seong-Jik

    2017-11-01

    In this study, we fabricated a nanofibrous composite (NFC) membrane as a substrate to produce forward osmosis (FO) membranes, and we also assessed the use of liquid fertilizer as a draw solution for the FO process in order to produce agricultural irrigation water. Commercial cellulose triacetate (CTA) and thin-film composite (TFC) FO membranes were included in this study. Under FO tests, the NFC, CTA, and TFC membranes achieved initial osmotic water flux values of 35.31, 6.85, and 3.31 L/m 2 ·h and final osmotic water flux values of 12.62, 6.31, and 3.85 L/m 2  h, respectively. The reason for the high osmotic water flux of the NFC membrane is because its nanofiber layer has low tortuosity, high porosity, and a low thickness, resulting in a reduction in the internal concentration polarization phenomenon. When liquid fertilizer was used as the draw solution, the water flux values in the FO experiments for the NFC, CTA, and TFC membranes were 15.54, 5.46, and 2.54 L/m 2  h. Finally, our results revealed that the FO process using liquid fertilizer as a draw solution can be applied to produce agricultural irrigation water from brackish water and the newly fabricated NFC membrane can be applied to the FO process.

  16. Boron in reverse osmosis water desalination: current situational and applying technologies for its removal; El boro en las aguas desaladas por osmosis inversa: situacion actual y tecnologias aplicables para su eliminacion

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigo Sanz, M.; Penate Suarez, B.

    2007-07-01

    In most of the seawater reverse osmosis desalination plants operating in one stage, the water produced presents values bordering or exceeding the limit established by the Spanish legislation for boron content of 1mg/l. As well as on the intrinsic features of the membrane elements, the boron removal in the desalination process depends on various factors. In this article the most relevant ones are described and a synopsis of the applied technologies and designs is introduced in order to fulfil current regulations. (Author)

  17. Environmental and economic impacts of fertilizer drawn forward osmosis and nanofiltration hybrid system

    KAUST Repository

    Kim, Jung Eun

    2017-05-08

    Environmental and economic impacts of the fertilizer drawn forward osmosis (FDFO) and nanofiltration (NF) hybrid system were conducted and compared with conventional reverse osmosis (RO) hybrid scenarios using microfiltration (MF) or ultrafiltration (UF) as a pre-treatment process. The results showed that the FDFO-NF hybrid system using thin film composite forward osmosis (TFC) FO membrane has less environmental impact than conventional RO hybrid systems due to lower consumption of energy and cleaning chemicals. The energy requirement for the treatment of mine impaired water by the FDFO-NF hybrid system was 1.08 kWh/m, which is 13.6% less energy than an MF-RO and 21% less than UF-RO under similar initial feed solution. In a closed-loop system, the FDFO-NF hybrid system using a TFC FO membrane with an optimum NF recovery rate of 84% had the lowest unit operating expenditure of AUD $0.41/m. Besides, given the current relatively high price and low flux performance of the cellulose triacetate and TFC FO membranes, the FDFO-NF hybrid system still holds opportunities to reduce operating expenditure further. Optimizing NF recovery rates and improving the water flux of the membrane would decrease the unit OPEX costs, although the TFC FO membrane would be less sensitive to this effect.

  18. Environmental and economic impacts of fertilizer drawn forward osmosis and nanofiltration hybrid system

    KAUST Repository

    Kim, Jung Eun; Phuntsho, Sherub; Chekli, Laura; Hong, Seungkwan; Ghaffour, NorEddine; Leiknes, TorOve; Choi, Joon Yong; Shon, Ho Kyong

    2017-01-01

    Environmental and economic impacts of the fertilizer drawn forward osmosis (FDFO) and nanofiltration (NF) hybrid system were conducted and compared with conventional reverse osmosis (RO) hybrid scenarios using microfiltration (MF) or ultrafiltration (UF) as a pre-treatment process. The results showed that the FDFO-NF hybrid system using thin film composite forward osmosis (TFC) FO membrane has less environmental impact than conventional RO hybrid systems due to lower consumption of energy and cleaning chemicals. The energy requirement for the treatment of mine impaired water by the FDFO-NF hybrid system was 1.08 kWh/m, which is 13.6% less energy than an MF-RO and 21% less than UF-RO under similar initial feed solution. In a closed-loop system, the FDFO-NF hybrid system using a TFC FO membrane with an optimum NF recovery rate of 84% had the lowest unit operating expenditure of AUD $0.41/m. Besides, given the current relatively high price and low flux performance of the cellulose triacetate and TFC FO membranes, the FDFO-NF hybrid system still holds opportunities to reduce operating expenditure further. Optimizing NF recovery rates and improving the water flux of the membrane would decrease the unit OPEX costs, although the TFC FO membrane would be less sensitive to this effect.

  19. RO applications and wastewater reuse - two important fossil power plant contributions to conservation of water resources; Umkehrosmose und Wiederverwertung von Abwasser - zwei wichtige Beitraege der Kraftwerksindustrie zur Schonung von Wasserresourcen

    Energy Technology Data Exchange (ETDEWEB)

    Fahlke, J. [Grosskraftwerk Mannheim AG (Germany)

    1999-07-01

    The concept of the new makeup treatment system with permeate-staged reverse osmosis proved successful since commissioning. One important advantage is the short time required from startup until reaching the full load (within approximately 15 minutes). The pH of the decarbonation outlet decisively affects the degassing of carbon dioxide and thus also the permeate conductivity. By dosing acid or caustic, optimal operating conditions may be adjusted for both the carbon dioxide removal in the vacuum degasifier and the salt retention in the reverse osmosis system. Thus, during continuous operation, the permeate conductivity of < 0.2 {mu}S/cm is achieved. As compared to the older concentrate-staged reverse osmosis system, the loading of the downstream condensate polishers is markedly reduced because of the considerably lower permeate conductivity. Recycling of cleaned ash quenching water for process water in the FGD is principally possible and done for eight years now, as is demonstrated by the example of Unit 7 of Grosskraftwerk Mannheim. The RO concentrate is recycled since November 1997. Since the start of this approach a total amount of 799,288 m{sup 3} ash quenching water and 198,778 m{sup 3} RO concentrate was recycled in units 7 and 8. For units 3 and 4, the recycled quantity of ash quenching water and RO concentrate amounts to 688,982 m{sup 3}. This equals 168,704 DM of saved well water extraction fees since the start of the recycling approach. (orig.) [German] Das Konzept der neuen Zusatzwasseraufbereitung mit permeatgestufter Umkehrosmose hat sich bestens bewaehrt. Der Hauptvorteil ist das schnelle Anfahren der Anlage vom Stillstand auf Vollast innerhalb von ca. 15 Minuten. Der pH Wert im Austritt der Entkarbonisierung beeinflusst die Entgasung von CO{sub 2} und damit auch die elektrische Leitfaehigkeit des Permeats. Durch das Eindosieren von HCl oder NaOH koennen auch bei schwankender Zulaufqualitaet die optimalen Betriebsbedingungen eingestellt werden. Im

  20. Forward Osmosis in Wastewater Treatment Processes

    DEFF Research Database (Denmark)

    Korenak, Jasmina; Basu, Subhankar; Balakrishnan, Malini

    2017-01-01

    In recent years, membrane technology has been widely used in wastewater treatment and water purification. Membrane technology is simple to operate and produces very high quality water for human consumption and industrial purposes. One of the promising technologies for water and wastewater treatment...... is the application of forward osmosis. Essentially, forward osmosis is a process in which water is driven through a semipermeable membrane from a feed solution to a draw solution due to the osmotic pressure gradient across the membrane. The immediate advantage over existing pressure driven membrane technologies...... briefly review some of the applications within water purification and new developments in forward osmosis membrane fabrication....

  1. Application of thin film composite membranes with forward osmosis technology for the separation of emulsified oil-water

    KAUST Repository

    Duong, Hoang Hanh Phuoc; Chung, Neal Tai-Shung

    2014-01-01

    Large amounts of oily wastewater have been produced from various industries. The main challenge of oily wastewater treatments is to separate the stable emulsified oil particles from water. Therefore, the aim of this study is to investigate the effectiveness of forward osmosis (FO) processes to treat the stable oil-water emulsions. The FO technique has been demonstrated successfully for the treatment of a wide range of oil-water emulsions from a low to a very high concentration up to 200,000. ppm. The dependence of separation performance on oily feed concentration and flow rate has been investigated. Water can be separated from oily feeds containing 500. ppm or 200,000. ppm emulsified oil at a relatively high flux of 16.5±1.2. LMH or 11.8±1.6. LMH respectively by using a thin film composite membrane PAN-TFC and 1. M NaCl as the draw solution. Moreover, this membrane can achieve an oil rejection of 99.88% to produce water with a negligible oil level. Due to the presence of emulsified oil particles in the oily feed solutions, the membrane fouling has been addressed in this study. Better anti-fouling TFC FO membranes are needed. © 2013 Elsevier B.V.

  2. Application of thin film composite membranes with forward osmosis technology for the separation of emulsified oil-water

    KAUST Repository

    Duong, Hoang Hanh Phuoc

    2014-02-01

    Large amounts of oily wastewater have been produced from various industries. The main challenge of oily wastewater treatments is to separate the stable emulsified oil particles from water. Therefore, the aim of this study is to investigate the effectiveness of forward osmosis (FO) processes to treat the stable oil-water emulsions. The FO technique has been demonstrated successfully for the treatment of a wide range of oil-water emulsions from a low to a very high concentration up to 200,000. ppm. The dependence of separation performance on oily feed concentration and flow rate has been investigated. Water can be separated from oily feeds containing 500. ppm or 200,000. ppm emulsified oil at a relatively high flux of 16.5±1.2. LMH or 11.8±1.6. LMH respectively by using a thin film composite membrane PAN-TFC and 1. M NaCl as the draw solution. Moreover, this membrane can achieve an oil rejection of 99.88% to produce water with a negligible oil level. Due to the presence of emulsified oil particles in the oily feed solutions, the membrane fouling has been addressed in this study. Better anti-fouling TFC FO membranes are needed. © 2013 Elsevier B.V.

  3. Economic Evaluation of a Hybrid Desalination System Combining Forward and Reverse Osmosis

    Science.gov (United States)

    Choi, Yongjun; Cho, Hyeongrak; Shin, Yonghyun; Jang, Yongsun; Lee, Sangho

    2015-01-01

    This study seeks to evaluate the performance and economic feasibility of the forward osmosis (FO)–reverse osmosis (RO) hybrid process; to propose a guideline by which this hybrid process might be more price-competitive in the field. A solution-diffusion model modified with film theory was applied to analyze the effects of concentration polarization, water, and salt transport coefficient on flux, recovery, seawater concentration, and treated wastewater of the FO process of an FO-RO hybrid system. A simple cost model was applied to analyze the effects of flux; recovery of the FO process; energy; and membrane cost on the FO-RO hybrid process. The simulation results showed that the water transport coefficient and internal concentration polarization resistance are very important factors that affect performance in the FO process; however; the effect of the salt transport coefficient does not seem to be large. It was also found that the flux and recovery of the FO process, the FO membrane, and the electricity cost are very important factors that influence the water cost of an FO-RO hybrid system. This hybrid system can be price-competitive with RO systems when its recovery rate is very high, the flux and the membrane cost of the FO are similar to those of the RO, and the electricity cost is expensive. The most important thing in commercializing the FO process is enhancing performance (e.g.; flux and the recovery of FO membranes). PMID:26729176

  4. Enhanced Performance of Thin Film Composite Forward Osmosis Membrane by Chemical Post-Treatment

    Science.gov (United States)

    Liu, Zheng; Chen, Jiangrong; Cao, Zhen; Wang, Jian; Guo, Chungang

    2018-01-01

    Forward osmosis is an attractive technique in water purification and desalination fields. Enhancement of the forward osmosis membrane performance is essential to the application of this technique. In this study, an optimized chemical post-treatment approach which was used to improve RO membrane performance was employed for enhancing water flux of thin film composite forward osmosis membrane. Home-made polysulfide-based forward osmosis membrane was prepared and nitric acid, sulfuric acid, ethanol, 2-propanol were employed as post-treatment solutions. After a short-term treatment, all the membrane samples manifested water flux enhancement compared with their untreated counterparts. Over 50% increase of water flux had been obtained by ethanol solution treatment. The swelling, changes of hydrophobicity and solvency in both active layer and substrate were verified as the major causes for the enhancement of the water flux. It is noted that the treatment time and solution concentration should be controlled to get both appropriate water flux and reverse salt flux. The results obtained in this study will be useful for further FO membrane development and application.

  5. Rejection of micropollutants by clean and fouled forward osmosis membrane

    KAUST Repository

    Valladares Linares, Rodrigo

    2011-12-01

    As forward osmosis (FO) gains attention as an efficient technology to improve wastewater reclamation processes, it is fundamental to determine the influence of fouling in the rejection of emerging contaminants (micropollutants). This study focuses on the rejection of 13 selected micropollutants, spiked in a secondary wastewater effluent, by a FO membrane, using Red Sea water as draw solution (DS), differentiating the effects on the rejection caused by a clean and fouled membrane. The resulting effluent was then desalinated at low pressure with a reverse osmosis (RO) membrane, to produce a high quality permeate and determine the rejection with a coupled forward osmosis - low pressure reverse osmosis (FO-LPRO) system. When considering only FO with a clean membrane, the rejection of the hydrophilic neutral compounds was between 48.6% and 84.7%, for the hydrophobic neutrals the rejection ranged from 40.0% to 87.5%, and for the ionic compounds the rejections were between 92.9% and 96.5%. With a fouled membrane, the rejections were between 44.6% and 95.2%, 48.7%-91.5% and 96.9%-98.6%, respectively. These results suggest that, except for the hydrophilic neutral compounds, the rejection of the micropollutants is increased by the presence of a fouling layer, possibly due to the higher hydrophilicity of the FO fouled membrane compared to the clean one, the increased adsorption capacity of hydrophilic compounds and reduced mass transport capacity, membrane swelling, and the higher negative charge of the membrane surface, related to the foulants composition, mainly NOM acids (carboxylic radicals) and polysaccharides or polysaccharide-like substances. However, when coupled with RO, the rejections in both cases increased above 96%. The coupled FO-LPRO system was an effective double barrier against the selected micropollutants. © 2011 Elsevier Ltd.

  6. Rejection of micropollutants by clean and fouled forward osmosis membrane

    KAUST Repository

    Valladares Linares, Rodrigo; Yangali-Quintanilla, Victor; Li, Zhenyu; Amy, Gary L.

    2011-01-01

    As forward osmosis (FO) gains attention as an efficient technology to improve wastewater reclamation processes, it is fundamental to determine the influence of fouling in the rejection of emerging contaminants (micropollutants). This study focuses on the rejection of 13 selected micropollutants, spiked in a secondary wastewater effluent, by a FO membrane, using Red Sea water as draw solution (DS), differentiating the effects on the rejection caused by a clean and fouled membrane. The resulting effluent was then desalinated at low pressure with a reverse osmosis (RO) membrane, to produce a high quality permeate and determine the rejection with a coupled forward osmosis - low pressure reverse osmosis (FO-LPRO) system. When considering only FO with a clean membrane, the rejection of the hydrophilic neutral compounds was between 48.6% and 84.7%, for the hydrophobic neutrals the rejection ranged from 40.0% to 87.5%, and for the ionic compounds the rejections were between 92.9% and 96.5%. With a fouled membrane, the rejections were between 44.6% and 95.2%, 48.7%-91.5% and 96.9%-98.6%, respectively. These results suggest that, except for the hydrophilic neutral compounds, the rejection of the micropollutants is increased by the presence of a fouling layer, possibly due to the higher hydrophilicity of the FO fouled membrane compared to the clean one, the increased adsorption capacity of hydrophilic compounds and reduced mass transport capacity, membrane swelling, and the higher negative charge of the membrane surface, related to the foulants composition, mainly NOM acids (carboxylic radicals) and polysaccharides or polysaccharide-like substances. However, when coupled with RO, the rejections in both cases increased above 96%. The coupled FO-LPRO system was an effective double barrier against the selected micropollutants. © 2011 Elsevier Ltd.

  7. Osmosis-induced water uptake by Eurobitum bituminized radioactive waste and pressure development in constant volume conditions

    International Nuclear Information System (INIS)

    Mariën, A.; Mokni, N.; Valcke, E.; Olivella, S.; Smets, S.; Li, X.

    2013-01-01

    Highlights: ► The water uptake by Eurobitum is studied to judge the safety of geological disposal. ► High pressures of up to 20 MPa are measured in constant volume water uptake tests. ► The morphology of leached Eurobitum samples is studied with μCT and ESEM. ► The observations are reproduced by an existing CHM formulation for Eurobitum. - Abstract: The chemo-hydro-mechanical (CHM) interaction between swelling Eurobitum radioactive bituminized waste (BW) and Boom Clay is investigated to assess the feasibility of geological disposal for the long-term management of this waste. These so-called compatibility studies include laboratory water uptake tests at Belgian Nuclear Research Center SCK-CEN, and the development of a coupled CHM formulation for Eurobitum by the International Center for Numerical Methods and Engineering (CIMNE, Polytechnical University of Cataluña, Spain). In the water uptake tests, the osmosis-induced swelling, pressure increase and NaNO 3 leaching of small cylindrical BW samples (diameter 38 mm, height 10 mm) is studied under constant total stress conditions and nearly constant volume conditions; the actual geological disposal conditions should be intermediate between these extremes. Two nearly constant volume tests were stopped after 1036 and 1555 days to characterize the morphology of the hydrated BW samples and to visualize the hydrated part with microfocus X-ray Computer Tomography (μCT) and Environmental Scanning Electron Microscopy (ESEM). In parallel, a coupled CHM formulation is developed that describes chemically and hydraulically coupled flow processes in porous materials with salt crystals, and that incorporates a porosity dependent membrane efficiency, permeability and diffusivity. When Eurobitum BW is hydrated in (nearly) constant volume conditions, the osmosis-induced water uptake results in an increasing pressure to values that can be (in theory) as high as 42.8 MPa, being the osmotic pressure of a saturated NaNO 3

  8. Bifunctional polymer hydrogel layers as forward osmosis draw agents for continuous production of fresh water using solar energy.

    Science.gov (United States)

    Razmjou, Amir; Liu, Qi; Simon, George P; Wang, Huanting

    2013-11-19

    The feasibility of bilayer polymer hydrogels as draw agent in forward osmosis process has been investigated. The dual-functionality hydrogels consist of a water-absorptive layer (particles of a copolymer of sodium acrylate and N-isopropylacrylamide) to provide osmotic pressure, and a dewatering layer (particles of N-isopropylacrylamide) to allow the ready release of the water absorbed during the FO drawing process at lower critical solution temperature (32 °C). The use of solar concentrated energy as the source of heat resulted in a significant increase in the dewatering rate as the temperature of dewatering layer increased to its LSCT more rapidly. Dewatering flux rose from 10 to 25 LMH when the solar concentrator increased the input energy from 0.5 to 2 kW/m(2). Thermodynamic analysis was also performed to find out the minimum energy requirement of such a bilayer hydrogel-driven FO process. This study represents a significant step forward toward the commercial implementation of hydrogel-driven FO system for continuous production of fresh water from saline water or wastewaters.

  9. Feasibility of the inverse osmosis; La viabilidad de la osmosis inversa

    Energy Technology Data Exchange (ETDEWEB)

    Farinas Iglesias, M.

    1999-11-01

    Within the different alternatives to the treatment of the water, the inverse osmosis is presented like the most interesting system, avant-garde and economical susceptible of investigation. Manuel Farinas exposes in the REVERSE OSMOSIS, the costs of the cubic meter of hasty water, as well as of other products gotten with this technic. (Author)

  10. Recovery of nitrogen and water from landfill leachate by a microbial electrolysis cell-forward osmosis system.

    Science.gov (United States)

    Qin, Mohan; Molitor, Hannah; Brazil, Brian; Novak, John T; He, Zhen

    2016-01-01

    A microbial electrolysis cell (MEC)-forward osmosis (FO) system was previously reported for recovering ammonium and water from synthetic solutions, and here it has been advanced with treating landfill leachate. In the MEC, 65.7±9.1% of ammonium could be recovered in the presence of cathode aeration. Without aeration, the MEC could remove 54.1±10.9% of ammonium from the leachate, but little ammonia was recovered. With 2M NH4HCO3 as the draw solution, the FO process achieved 51% water recovery from the MEC anode effluent in 3.5-h operation, higher than that from the raw leachate. The recovered ammonia was used as a draw solute in the FO for successful water recovery from the treated leachate. Despite the challenges with treating returning solution from the FO, this MEC-FO system has demonstrated the potential for resource recovery from wastes, and provide a new solution for sustainable leachate management. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Forward Osmosis Brine Drying

    Science.gov (United States)

    Flynn, Michael; Shaw, Hali; Hyde, Deirdre; Beeler, David; Parodi, Jurek

    2015-01-01

    The Forward Osmosis Brine Drying (FOBD) system is based on a technique called forward osmosis (FO). FO is a membrane-based process where the osmotic potential between brine and a salt solution is equalized by the movement of water from the brine to the salt solution. The FOBD system is composed of two main elements, the FO bag and the salt regeneration system. This paper discusses the results of testing of the FO bag to determine the maximum water recovery ratio that can be attained using this technology. Testing demonstrated that the FO bag is capable of achieving a maximum brine water recovery ratio of the brine of 95%. The equivalent system mass was calculated to be 95 kg for a feed similar to the concentrated brine generated on the International Space Station and 86 kg for an Exploration brine. The results have indicated that the FOBD can process all the brine for a one year mission for between 11% to 10% mass required to bring the water needed to make up for water lost in the brine if not recycled. The FOBD saves 685 kg and when treating the International Space Station brine and it saves 829 kg when treating the Exploration brine. It was also demonstrated that saturated salt solutions achieve a higher water recovery ratios than solids salts do and that lithium chloride achieved a higher water recovery ratio than sodium chloride.

  12. Does Chlorination of Seawater Reverse Osmosis Membranes Control Biofouling?

    KAUST Repository

    Khan, Muhammad Tariq; Hong, Pei-Ying; Nada, Nabil; Croue, Jean Philippe

    2015-01-01

    Biofouling is the major problem of reverse osmosis (RO) membranes used for desalting seawater (SW). The use of chlorine is a conventional and common practice to control/prevent biofouling. Unlike polyamide RO membranes, cellulose triacetate (CTA) RO membranes display a high chlorine tolerance. Due to this characteristic, CTA membranes are used in most of the RO plants located in the Middle East region where the elevated seawater temperature and water quality promote the risk of membrane biofouling. However, there is no detailed study on the investigation/characterization of CTA-RO membrane fouling. In this investigation, the fouling profile of a full–scale SWRO desalination plant operating with not only continuous chlorination of raw seawater but also intermittent chlorination of CTA-RO membranes was studied. Detailed water quality and membrane fouling analyses were conducted. Profiles of microbiological, inorganic, and organic constituents of analysed fouling layers were extensively discussed. Our results clearly identified biofilm development on these membranes. The incapability of chlorination on preventing biofilm formation on SWRO membranes could be assigned to its failure in effectively reaching throughout the different regions of the permeators. This failure could have occurred due to three main factors: plugging of membrane fibers, chlorine consumption by organics accumulated on the front side fibers, or chlorine adaptation of certain bacterial populations.

  13. Does Chlorination of Seawater Reverse Osmosis Membranes Control Biofouling?

    KAUST Repository

    Khan, Muhammad Tariq

    2015-04-01

    Biofouling is the major problem of reverse osmosis (RO) membranes used for desalting seawater (SW). The use of chlorine is a conventional and common practice to control/prevent biofouling. Unlike polyamide RO membranes, cellulose triacetate (CTA) RO membranes display a high chlorine tolerance. Due to this characteristic, CTA membranes are used in most of the RO plants located in the Middle East region where the elevated seawater temperature and water quality promote the risk of membrane biofouling. However, there is no detailed study on the investigation/characterization of CTA-RO membrane fouling. In this investigation, the fouling profile of a full–scale SWRO desalination plant operating with not only continuous chlorination of raw seawater but also intermittent chlorination of CTA-RO membranes was studied. Detailed water quality and membrane fouling analyses were conducted. Profiles of microbiological, inorganic, and organic constituents of analysed fouling layers were extensively discussed. Our results clearly identified biofilm development on these membranes. The incapability of chlorination on preventing biofilm formation on SWRO membranes could be assigned to its failure in effectively reaching throughout the different regions of the permeators. This failure could have occurred due to three main factors: plugging of membrane fibers, chlorine consumption by organics accumulated on the front side fibers, or chlorine adaptation of certain bacterial populations.

  14. Nanofiltration vs. reverse osmosis for the removal of emerging organic contaminants in water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor; Maeng, Sung Kyu; Fujioka, Takahiro; Kennedy, Maria; Li, Zhenyu; Amy, Gary L.

    2011-01-01

    study, results of NF and RO pilot and full-scale experiments where compared to our experimental results. The removal results showed that NF can remove many emerging contaminants. The average removal by tight NF was 82% for neutral contaminants and 97

  15. Separation performance and interfacial properties of nanocomposite reverse osmosis membranes

    KAUST Repository

    Pendergast, MaryTheresa M.; Ghosh, Asim K.; Hoek, E.M.V.

    2013-01-01

    Four different types of nanocomposite reverse osmosis (RO) membranes were formed by interfacial polymerization of either polyamide (PA) or zeolite A-polyamide nanocomposite (ZA-PA) thin films over either pure polysulfone (PSf) or zeolite A-polysulfone nanocomposite (ZA-PSf) support membranes cast by wet phase inversion. All three nanocomposite membranes exhibited superior separation performance and interfacial properties relative to hand-cast TFC analogs including: (1) smoother, more hydrophilic surfaces (2) higher water permeability and salt rejection, and (3) improved resistance to physical compaction. Less compaction occurred for membranes with nanoparticles embedded in interfacially polymerized coating films, which adds further proof that flux decline associated with physical compaction is influenced by coating film properties in addition to support membrane properties. The new classes of nanocomposite membrane materials continue to offer promise of further improved RO membranes for use in desalination and advanced water purification. © 2011 Elsevier B.V.

  16. Highly permeable double-skinned forward osmosis membranes for anti-fouling in the emulsified oil-water separation process

    KAUST Repository

    Duong, Hoang Hanh Phuoc; Chung, Neal Tai-Shung; Wei, Shawn; Irish, Lana

    2014-01-01

    Forward osmosis (FO) has attracted wide attention in recent years. However, the FO performance may be restricted due to internal concentration polarization (ICP) and fast fouling propensity that occurs in the membrane sublayer. Particularly, these problems significantly affect the membrane performance when treating highly contaminated oily wastewater. Recently, double-skinned flat sheet cellulose acetate (CA) membranes consisting of two selective skins via the phase inversion method have demonstrated less ICP and fouling propensity over typical single-skinned membranes. However, these membranes exhibit low water fluxes of <12 LMH under 2 M NaCl draw solution. Therefore, a novel double-skinned FO membrane with a high water flux has been aimed for in this study for emulsified oil-water treatment. The double-skinned FO membrane comprises a fully porous sublayer sandwiched between (i) a truly dense skin for salt rejection and (ii) a fairly loose dense skin for emulsified oil particle rejection. The former dense skin is a polyamide synthesized via interfacial polymerization, while the latter one is a self-assembled sulfonated pentablock copolymer (Nexar copolymer) layer. The resultant double-skinned membrane exhibits a high water flux of 17.2 LMH and a low reverse salt transport of 4.85 gMH using 0.5 M NaCl as the draw solution and DI water as the feed. The double-skinned membrane outperforms the single-skinned membrane with much lower fouling propensity for emulsified oil-water separation. © 2014 American Chemical Society.

  17. Highly permeable double-skinned forward osmosis membranes for anti-fouling in the emulsified oil-water separation process

    KAUST Repository

    Duong, Hoang Hanh Phuoc

    2014-04-15

    Forward osmosis (FO) has attracted wide attention in recent years. However, the FO performance may be restricted due to internal concentration polarization (ICP) and fast fouling propensity that occurs in the membrane sublayer. Particularly, these problems significantly affect the membrane performance when treating highly contaminated oily wastewater. Recently, double-skinned flat sheet cellulose acetate (CA) membranes consisting of two selective skins via the phase inversion method have demonstrated less ICP and fouling propensity over typical single-skinned membranes. However, these membranes exhibit low water fluxes of <12 LMH under 2 M NaCl draw solution. Therefore, a novel double-skinned FO membrane with a high water flux has been aimed for in this study for emulsified oil-water treatment. The double-skinned FO membrane comprises a fully porous sublayer sandwiched between (i) a truly dense skin for salt rejection and (ii) a fairly loose dense skin for emulsified oil particle rejection. The former dense skin is a polyamide synthesized via interfacial polymerization, while the latter one is a self-assembled sulfonated pentablock copolymer (Nexar copolymer) layer. The resultant double-skinned membrane exhibits a high water flux of 17.2 LMH and a low reverse salt transport of 4.85 gMH using 0.5 M NaCl as the draw solution and DI water as the feed. The double-skinned membrane outperforms the single-skinned membrane with much lower fouling propensity for emulsified oil-water separation. © 2014 American Chemical Society.

  18. Remediating biofouling of reverse osmosis membranes

    International Nuclear Information System (INIS)

    Siler, J.L.

    1991-01-01

    Several potential additives and the use of influent pH adjustment were examined to remediated the biofouling problem of the ETF reverse osmosis (RO) system. Tests were conducted with simulated RO feed containing salt, metal hydroxides and bacteria. The addition of sodium hexametaphosphate (SHMP), sodium bisulfite, and adjusting the influent pH to 3 were each successful in reducing the RO biofouling. Little or no benefit was found from the use of a biofilm remover (Filmtec Alkaline Cleaner) or the use of surfactants (Surfynol or sodium lauryl sulfate). In addition, Surfynol use resulted in irreversible fouling and necessitated membrane replacement. At the water recoveries used in the ETF (>90%), sodium bisulfite addition resulted in the recovery of 70--90% of the flux and almost complete restoration of the DF to prefouled conditions. Based on the bench-scale tests completed, IWT would recommend that sodium bisulfite addition be tested at the ETF. This testing would involve optimizing the amount of bisulfite required. In addition, it is recommended that the addition of SHMP or influent pH adjustment be evaluated since the relative differences in labscale tests were small and scale-up effects could be present. The ETF operating permit allows each to be added

  19. Fertilizer drawn forward osmosis process for sustainable water reuse to grow hydroponic lettuce using commercial nutrient solution

    KAUST Repository

    Chekli, Laura; Eun Kim, Jung; El Saliby, Ibrahim; Kim, Youngjin; Phuntsho, Sherub; Li, Sheng; Ghaffour, NorEddine; Leiknes, TorOve; Kyong Shon, Ho

    2017-01-01

    This study investigated the sustainable reuse of wastewater using fertilizer drawn forward osmosis (FDFO) process through osmotic dilution of commercial nutrient solution for hydroponics, a widely used technique for growing plants without soil

  20. RO-PRO desalination: An integrated low-energy approach to seawater desalination

    International Nuclear Information System (INIS)

    Prante, Jeri L.; Ruskowitz, Jeffrey A.; Childress, Amy E.; Achilli, Andrea

    2014-01-01

    Highlights: • In the novel RO-PRO system, the energy produced by PRO is utilized to offset the energy consumed by the RO. • The specific energy consumption of a RO-PRO system was modeled for the first time. • A novel module-based PRO model for full-scale applications was developed. • The minimum net specific energy consumption of the modeled RO-PRO system was 1.2 kW h/m 3 at 50% RO recovery. • A sensitivity analysis showed a min RO-PRO specific energy consumption of 1.0 kW h/m 3 and a max power density of 10 W/m 2 . - Abstract: Although reverse osmosis (RO) is currently the most energy efficient desalination technology, it still requires a great deal of energy to create the high pressures necessary to desalinate seawater. An opposite process of RO, called pressure retarded osmosis (PRO), utilizes the salinity gradient between a relatively fresh impaired water source and seawater to produce pressure and hence, energy. In this paper, PRO is evaluated in conjunction with RO, in a system called RO-PRO desalination, to reduce the energy requirement of seawater RO desalination. RO-PRO specific energy consumption was modeled using RO conditions at the thermodynamic restriction and a newly developed module-based PRO model. Using a well-characterized cellulose triacetate (CTA) membrane, the minimum net specific energy consumption of the system was found to be approximately 40% lower than state-of-the-art seawater RO. A sensitivity analysis was performed to determine the effects of membrane characteristics on the specific energy production of the PRO process in the RO-PRO system. The sensitivity analysis showed that the minimum specific energy consumption using virtual membranes is approximately 1.0 kW h per m 3 of RO permeate at 50% RO recovery and that a maximum power density of approximately 10 W/m 2 could be achieved

  1. Research on rejection performance of reverse osmosis to manganese in simulated radioactive wastewater

    International Nuclear Information System (INIS)

    Kong Jinsong; Wang Xiaowei

    2012-01-01

    In order to reveal the performance of reverse osmosis applied in the radioactive wastewater treatment, treatment experiments are carried out on a pilot RO equipment using wastewater containing manganese nuclide. Results show that the rejection ratio of RO to manganese is almost not influenced by the operation pressure and the ration of reclaiming, and has no direct relation with the salt rejection ratio. The ratio of manganese rejection is more than 95% and can meet the requirement on the disposal of radioactive wastewater produced by pressurized water reactors. (authors)

  2. Permeability of uncharged organic molecules in reverse osmosis desalination membranes.

    Science.gov (United States)

    Dražević, Emil; Košutić, Krešimir; Svalina, Marin; Catalano, Jacopo

    2017-06-01

    Reverse osmosis (RO) membranes are primarily designed for removal of salts i.e. for desalination of brackish and seawater, but they have also found applications in removal of organic molecules. While it is clear that steric exclusion is the dominant removal mechanism, the fundamental explanation for how and why the separation occurs remains elusive. Until recently there was no strong microscopic evidences elucidating the structure of the active polyamide layers of RO membranes, and thus they have been conceived as "black boxes"; or as an array of straight capillaries with a distribution of radii; or as polymers with a small amount of polymer free domains. The knowledge of diffusion and sorption coefficients is a prerequisite for understanding the intrinsic permeability of any organic solute in any polymer. At the same time, it is technically challenging to accurately measure these two fundamental parameters in very thin (20-300 nm) water-swollen active layers. In this work we have measured partition and diffusion coefficients and RO permeabilities of ten organic solutes in water-swollen active layers of two types of RO membranes, low (SWC4+) and high flux (XLE). We deduced from our results and recent microscopic studies that the solute flux of organic molecules in polyamide layer of RO membranes occurs in two domains, dense polymer (the key barrier layer) and the water filled domains. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Exploring Water Taxation Systems Logo East Project RO05.13

    Directory of Open Access Journals (Sweden)

    Adrian Mihai INCEU

    2008-02-01

    Full Text Available In the first part of the paper the stages of our researches, the objectives and the methodology are presented. The paper focus on creating an evaluation system in order to compare the water taxation systems in the following countries: Holland, Hungary and Romania. This evaluation system is important if one takes in consideration the particularities of these systems. More than that, the comparison must take in consideration two very different systems: a centralized one in Holland and a decentralized one in Hungary and Romania.

  4. Non-linear osmosis

    Science.gov (United States)

    Diamond, Jared M.

    1966-01-01

    1. The relation between osmotic gradient and rate of osmotic water flow has been measured in rabbit gall-bladder by a gravimetric procedure and by a rapid method based on streaming potentials. Streaming potentials were directly proportional to gravimetrically measured water fluxes. 2. As in many other tissues, water flow was found to vary with gradient in a markedly non-linear fashion. There was no consistent relation between the water permeability and either the direction or the rate of water flow. 3. Water flow in response to a given gradient decreased at higher osmolarities. The resistance to water flow increased linearly with osmolarity over the range 186-825 m-osM. 4. The resistance to water flow was the same when the gall-bladder separated any two bathing solutions with the same average osmolarity, regardless of the magnitude of the gradient. In other words, the rate of water flow is given by the expression (Om — Os)/[Ro′ + ½k′ (Om + Os)], where Ro′ and k′ are constants and Om and Os are the bathing solution osmolarities. 5. Of the theories advanced to explain non-linear osmosis in other tissues, flow-induced membrane deformations, unstirred layers, asymmetrical series-membrane effects, and non-osmotic effects of solutes could not explain the results. However, experimental measurements of water permeability as a function of osmolarity permitted quantitative reconstruction of the observed water flow—osmotic gradient curves. Hence non-linear osmosis in rabbit gall-bladder is due to a decrease in water permeability with increasing osmolarity. 6. The results suggest that aqueous channels in the cell membrane behave as osmometers, shrinking in concentrated solutions of impermeant molecules and thereby increasing membrane resistance to water flow. A mathematical formulation of such a membrane structure is offered. PMID:5945254

  5. Development of a simplified treatment for measuring tritium concentration in the environmental water. Removal of dissolved ions by reverse osmosis membrane for electrolysis enrichment

    International Nuclear Information System (INIS)

    Koganezawa, Takayuki; Iida, Takao; Ogata, Yoshimune; Tsuji, Naruhito; Kakiuchi, Masahisa; Satake, Hiroshi; Yamanishi, Hirokuni; Sakuma, Yoichi

    2004-01-01

    An apparatus for tritium enrichment by electrolysis using solid polymer electrolyte was recently developed. The apparatus has the advantage that is to be electrolyzed without adding electrolyte to the sample water. The new treatment both being replaced the distillation process with filtration before electrolysis and being omitted the distillation process after electrolysis, was proposed. Impurities eluted by the electrolysis of ultra pure water with the device introduced no influence on tritium measurement. As alternative treatment to distillation before enrichment, micro filtration and reverse osmosis was carried out. When the sample water treated by micro filtration was electrolyzed, ions adhered both to the electrodes and the solid polymer electrolyte of the device since micro filtration cannot remove ions in the sample water. Therefore, the sample water treated by micro filtration caused some troubles in the electrolysis device. On the other hand, the sample water treated by reverse osmosis did not cause any troubles because it could remove ions. Applying the new treatment to measure some environmental waters, such as river water, resulted in an effective measurement without any influence to liquid scintillation counting. The results proved that a period of the pretreatment process of the water sample could be decreased from about 2 days to about 1.5 hours by applying the proposed treatment. A simplified treatment on the procedure of electrolysis enrichment was established for tritium measurements in the environmental water samples via liquid scintillation counting. (author)

  6. Treatment of dairy effluent model solutions by nanofiltration and reverse osmosis

    Directory of Open Access Journals (Sweden)

    I. Kyrychuk

    2015-05-01

    Full Text Available Introduction. Dairy industry generates a large amount of wastewaters that have high concentrations and contain milk components. Membrane processes have been shown to be convenient for wastewater treatment recovering milk components present in wastewaters and producing treated water. Materials and methods. The experiments were carried out in an unstirred batch sell using nanofiltration membranes OPMN-P (ZAO STC “Vladipor”, Russian Federation and reverse osmosis membranes NanoRo, ZAO (“RM Nanotech”, Russian Federation. The model solutions of dairy effluents –diluted skim and whole milk were used. Results. The nanofiltration and reverse osmosis membranes showed the same permeate flux during the concentration of model solutions of dairy effluents. The reason of this was likely membrane fouling with feed components. The fouling indexes indicated the fouling factor that was higher for RO. The higher permeate quality was obtainedwith RO membranes. The NF permeate containing up to 0.4 g/L of lactose and 0.75 g/L of mineral salts can be discharged or after finishing trеatment (e.g. RO or other can be reused. The obtained NF and RO retentate corresponds to milk in composition and can be used for non-food applications or as feed supplement for animals. Conclusions.The studied RO and NF membranes can be used for concentration of dairy effluents at low pressure. They showed better performance and separation characteristics comparing with data of other membranes available in the literature.

  7. Aquifer composition and the tendency toward scale-deposit formation during reverse osmosis desalination - Examples from saline ground water in New Mexico, USA

    Science.gov (United States)

    Huff, G.F.

    2006-01-01

    Desalination is expected to make a substantial contribution to water supply in the United States by 2020. Currently, reverse osmosis is one of the most cost effective and widely used desalination technologies. The tendency to form scale deposits during reverse osmosis is an important factor in determining the suitability of input waters for use in desalination. The tendency toward scale formation of samples of saline ground water from selected geologic units in New Mexico was assessed using simulated evaporation. All saline water samples showed a strong tendency to form CaCO3 scale deposits. Saline ground water samples from the Yeso Formation and the San Andres Limestone showed relatively stronger tendencies to form CaSO4 2H2O scale deposits and relatively weaker tendencies to form SiO2(a) scale deposits than saline ground water samples from the Rio Grande alluvium. Tendencies toward scale formation in saline ground water samples from the Dockum Group were highly variable. The tendencies toward scale formation of saline waters from the Yeso Formation, San Andres Limestone, and Rio Grande alluvium appear to correlate with the mineralogical composition of the geologic units, suggesting that scale-forming tendencies are governed by aquifer composition and water-rock interaction. ?? 2006 Elsevier B.V. All rights reserved.

  8. Boiler feedwater treatment using reverse osmosis at Suncor OSG

    International Nuclear Information System (INIS)

    Brown, T.

    1997-01-01

    The installation of a new 1000 cu m/hr reverse osmosis water treatment system for boiler feedwater at a Suncor plant was discussed. The selection process began in 1993 when Suncor identified a need to increase its boiler feedwater capacity. The company reviewed many options available to increase the treated water capacity. These included: contracting the supply of treated water, adding additional capacity, replacing the entire plant, reverse osmosis, and demineralization. The eventual decision was to build a new 1000 cu m/hr reverse osmosis water treatment plant with the following key components: a Degremont Infilco Ultra Pulsator Clarifier and a Glegg Water Conditioning multimedia filter, Amberpack softeners and reverse osmosis arrays. The reverse osmosis plant was environmentally favourable over an equivalent demineralization plant. A technical comparison was provided between demineralization and reverse osmosis. The system has proven to be successful and economical in meeting the plants needs. 5 figs

  9. REVERSE OSMOSIS CONCENTRATION OF ORANGE JUICE USING SPIRAL WOUND MEMBRANES

    Directory of Open Access Journals (Sweden)

    W. A. de ARAUJO

    2009-03-01

    Full Text Available

    Flavor and odor components of foods are often lost during processing which leads to a poorer quality final product compared with the fresh ingredients. The orange juice industry concentrates juice (45-66ºBrix in TASTE (Thermally Accelerated Short Time Evaporator to remove excess water, and thus reduce storage and transportation costs, but also to improve product stability. Evaporation results in a loss of fresh juice flavors, color degradation and “cooked” taste due to the thermal effects. Methods using less heat for thermal damage reduction must be investigated to establish parameters for future commercial processes. The promising alternative is Reverse Osmosis (RO, but it cannot achieve concentrations greater than 30ºBrix. RO has advantages over traditional evaporation techniques in removing water. Because less heat is used, thermal damage to products is generally eliminated. In this project tests were performed using unpasteurised Single Strength Orange Juice (SSOJ, spiral wound membranes (Polyamide, and a DESAL pilot system model 4040. The aim was to evaluate spiral wound membranes on the basis of flux as a function of time. Retentate concentrations were 15-20ºBrix, and GC-FID analyses were used in order to understand aroma losses. KEYWORDS: Orange; juice; membrane; concentration; osmosis; reverse.

  10. A novel reverse osmosis membrane modified by polyvinyl alcohol with maleic anhydride crosslinking

    Science.gov (United States)

    Samnani, Mohit; Rathod, Harshad; Raval, Hiren

    2018-03-01

    In the era of increasing energy crisis, it is inevitable to decrease process energy consumption to increase process viability and curtail green-house gas emission. The Reverse Osmosis plant requires significant energy to transfer water overcoming the osmotic pressure. This paper focuses on increasing the water flux for Thin Film Composite Reverse Osmosis (TFC RO) membrane without compromising salt rejection performance leading to the environmentally friendly and economically attractive process. The virgin TFC RO membrane was exposed to solution of sodium hypochlorite of concentration 2000 mg l-1 for 1 h to activate the surface of the membrane, followed by the treatment with the mixture of polyvinyl alcohol and maleic anhydride with varying concentrations for 1 h and curing in the oven at 80 °C temperature for 10 min. Out of all the treated membranes, the membrane treated with 2000 mg l-1 polyvinyl alcohol and 1000 mg l-1 maleic anhydride demonstrated the highest salt rejection of 96.83 % with 2% increase as compared to the virgin TFC RO membrane. The water flux of the membrane was around 44% higher than the virgin TFC RO membrane. The membrane samples were characterized by atomic force micrographs, ATR-FTIR, Nuclear magnetic resonance and Dynamic mechanical analysis.

  11. Emerging forward osmosis (FO) technologies and challenges ahead for clean water and clean energy applications

    KAUST Repository

    Chung, Tai-Shung

    2012-08-01

    The purpose of this short review is to share our understanding and perspectives with the chemical, environmental, water and osmotic power communities on FO processes in order to conduct meaningful R & D and develop effective and sustainable FO technologies for clean water and clean energy. © 2012 Elsevier Ltd. All rights reserved.

  12. Emerging forward osmosis (FO) technologies and challenges ahead for clean water and clean energy applications

    KAUST Repository

    Chung, Tai-Shung; Li, Xue; Ong, Rui Chin; Ge, Qingchun; Wang, Honglei; Han, Gang

    2012-01-01

    The purpose of this short review is to share our understanding and perspectives with the chemical, environmental, water and osmotic power communities on FO processes in order to conduct meaningful R & D and develop effective and sustainable FO technologies for clean water and clean energy. © 2012 Elsevier Ltd. All rights reserved.

  13. Evaluation of fertilizer-drawn forward osmosis for sustainable agriculture and water reuse in arid regions

    KAUST Repository

    Chekli, Laura

    2016-11-25

    The present study focused on the performance of the FDFO process to achieve simultaneous water reuse from wastewater and production of nutrient solution for hydroponic application. Bio-methane potential (BMP) measurements were firstly carried out to determine the effect of osmotic concentration of wastewater achieved in the FDFO process on the anaerobic activity. Results showed that 95% water recovery from the FDFO process is the optimum value for further AnMBR treatment. Nine different fertilizers were then tested based on their FO performance (i.e. water flux, water recovery and reverse salt flux) and final nutrient concentration. From this initial screening, ammonium phosphate monobasic (MAP), ammonium sulfate (SOA) and mono-potassium phosphate were selected for long term experiments to investigate the maximum water recovery achievable. After the experiments, hydraulic membrane cleaning was performed to assess the water flux recovery. SOA showed the highest water recovery rate, up to 76% while KH2PO4 showed the highest water flux recovery, up to 75% and finally MAP showed the lowest final nutrient concentration. However, substantial dilution was still necessary to comply with the standards for fertigation even if the recovery rate was increased.

  14. Evaluation of fertilizer-drawn forward osmosis for sustainable agriculture and water reuse in arid regions.

    Science.gov (United States)

    Chekli, Laura; Kim, Youngjin; Phuntsho, Sherub; Li, Sheng; Ghaffour, Noreddine; Leiknes, TorOve; Shon, Ho Kyong

    2017-02-01

    The present study focused on the performance of the FDFO process to achieve simultaneous water reuse from wastewater and production of nutrient solution for hydroponic application. Bio-methane potential (BMP) measurements were firstly carried out to determine the effect of osmotic concentration of wastewater achieved in the FDFO process on the anaerobic activity. Results showed that 95% water recovery from the FDFO process is the optimum value for further AnMBR treatment. Nine different fertilizers were then tested based on their FO performance (i.e. water flux, water recovery and reverse salt flux) and final nutrient concentration. From this initial screening, ammonium phosphate monobasic (MAP), ammonium sulfate (SOA) and mono-potassium phosphate were selected for long term experiments to investigate the maximum water recovery achievable. After the experiments, hydraulic membrane cleaning was performed to assess the water flux recovery. SOA showed the highest water recovery rate, up to 76% while KH 2 PO 4 showed the highest water flux recovery, up to 75% and finally MAP showed the lowest final nutrient concentration. However, substantial dilution was still necessary to comply with the standards for fertigation even if the recovery rate was increased. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Bioluminescence-Based Method for Measuring Assimilable Organic Carbon in Pretreatment Water for Reverse Osmosis Membrane Desalination ▿

    Science.gov (United States)

    Weinrich, Lauren A.; Schneider, Orren D.; LeChevallier, Mark W.

    2011-01-01

    A bioluminescence-based assimilable organic carbon (AOC) test was developed for determining the biological growth potential of seawater within the reverse osmosis desalination pretreatment process. The test uses Vibrio harveyi, a marine organism that exhibits constitutive luminescence and is nutritionally robust. AOC was measured in both a pilot plant and a full-scale desalination plant pretreatment. PMID:21148685

  16. Present status of and subjects on the industrial utilization of polymer separation membranes. Japan`s first largest sea water desalination plant by RO; Kobunshi bunrimaku no sangyo riyo no genjo to kadai. Zosui bun`ya ni okeru maku riyo

    Energy Technology Data Exchange (ETDEWEB)

    Furuichi, M. [Kurita Water Industries Ltd., Tokyo (Japan)

    1998-07-05

    The utilization in Japan and abroad is discussed of desalination methods using evaporation, reverse osmosis (RO) membranes, and electrodialysis membranes, out of various desalination techniques for seawater and others containing more salt. A new seawater desalination plant built in Okinawa, Japan, is outlined, and the future trend of Japan`s efforts for desalination is predicted. The said plant in Okinawa is the largest ever built in this country, and occupies 4th or 5th place in terms of capacity among similar facilities across the world. It was completed in April, 1997, and produces pure water at a rate of 40,000m{sup 3}/day. This plant, operating on RO, comprises eight RO membrane units each capable of 5131{sup 3}/day. The membranes are of the spiral type, consisting of Toray`s crosslinked aramid-base composite membranes and Nitto Denko`s membranes composed totally of crosslinked aromatic polyamide. The greatest of the pending tasks is to reduce the desalination cost. As for the operating cost of the desalination facility at the current stage, it costs 120-130 yen/m{sup 3} on the 40,000m{sup 3}/day scale, and the power cost occupies approximately 60% of the total operating cost. It is concluded that the consumption of electric power and chemicals per pure water produced have to be reduced. 8 refs., 5 figs., 5 tabs.

  17. Effect of water temperature on biofouling development in reverse osmosis membrane systems

    KAUST Repository

    Farhat, Nadia; Vrouwenvelder, Johannes S.; van Loosdrecht, Mark C.M.; Bucs, Szilard; Staal, Marc

    2016-01-01

    temperatures, different biofilm activities, structures, and quantities were found, indicating that diagnosis of biofouling of membranes operated at different or varying (seasonal) feed water temperatures may be challenging. Membrane installations with a high

  18. Solar Desalination System Model for Sizing of Photovoltaic Reverse Osmosis (PVRO)

    KAUST Repository

    Habib, Abdulelah; Zamani, Vahraz; Kleissl, Jan

    2015-01-01

    loads, are considered as an ON/OFF units to track these solar energy variations. Reverse osmosis units are different in sizes and numbers. Various combinations of reverse osmosis units in size and capacity provide different water desalination system

  19. A novel reverse-osmosis wash water recycle system for manned space stations

    Science.gov (United States)

    Ray, R. J.; Babcock, W. C.; Barss, R. P.; Andrews, T. A.; Lachapelle, E. D.

    1984-01-01

    The preliminary development of a wash water recycle system utilizing an inside-skinned hollow-fiber membrane is described. This module configuration is based on tube-side feed and is highly resistant to fouling with a minimum of pretreatment. During an ongoing research program for NASA, these modules were operated on actual wash waters with no significant fouling for a period of 40 days. Due to the tube-side-feed flow in these hollow-fiber membranes, the fibers themselves become the pressure vessels, allowing the development of extremely lightweight membrane modules. During the NASA research program, a pre-prototype membrane module capable of processing 6 gallons per day of wash water at 97 percent recovery was developed that can be dry-stored and that weighs 120 g.

  20. Application of monochloramine for wastewater reuse: Effect on biostability during transport and biofouling in RO membranes

    KAUST Repository

    Farhat, Nadia

    2018-02-23

    The rising demand for clean and safe water has increased the interest in advanced wastewater treatment and reuse. Reverse osmosis (RO) can provide reliable and high-quality water from treated wastewater. Biofouling inevitably occurs, certainly with wastewater effluents, resulting in RO performance decline and operational problems. Chlorination of feed water has been commonly applied to limit biological growth. However, chlorine use may lead to a loss of membrane integrity of RO systems. In this study the potential of monochloramine as an alternative for chlorine was studied by (i) evaluating the biological stability of a full-scale wastewater membrane bioreactor (MBR) effluent during transport over 13 km to a full-scale RO plant and (ii) assessing the biofouling control potential in membrane fouling simulator (MFS) and pilot-scale RO installation. Microbial water analysis was performed on samples taken at several locations in the full-scale water reuse system (MBR effluent, during transport, and at the RO inlet and outlet) using a suite of tools including heterotrophic plate counts (HPC), adenosine triphosphate (ATP), flow cytometry (FCM), and 16 S rRNA gene pyrosequencing. Growth potential tests were used to evaluate the effect of monochloramine presence and absence on bacterial growth. Results showed limited changes in the microbial water quality in the presence of monochloramine. MFS studies showed that membrane biofouling could be effectively repressed by monochloramine over prolonged time periods. The normalized salt passage in a pilot RO system with monochloramine dosage was constant over a one year period (data of last 130 days presented), demonstrating that no membrane damage occurred. From this study, it can be concluded that monochloramine dosage in wastewater applications is effective in controlling biofouling in RO systems and maintaining a monochloramine residual during water transport provides biologically stable water.

  1. Pilot study on arsenic removal from groundwater using a small-scale reverse osmosis system-Towards sustainable drinking water production.

    Science.gov (United States)

    Schmidt, Stefan-André; Gukelberger, Ephraim; Hermann, Mario; Fiedler, Florian; Großmann, Benjamin; Hoinkis, Jan; Ghosh, Ashok; Chatterjee, Debashis; Bundschuh, Jochen

    2016-11-15

    Arsenic contamination of groundwater is posing a serious challenge to drinking water supplies on a global scale. In India and Bangladesh, arsenic has caused the most serious public health issue in the world for nearly two decades. The aim of this work was to study an arsenic removal system based on reverse osmosis at pilot scale treating two different water sources from two different locations in the State of Bihar, India. For this purpose two villages, Bind Toli and Ramnagar in the Patna District were selected, both located very close to the river Ganga. The trials were conducted with aerated and non-aerated groundwater. It is the first time that the arsenic removal efficiency for aerated and non-aerated groundwater by reverse osmosis technology in combination with an energy-saving recovery system have been studied. As the principle of reverse osmosis requires a relatively high pressure, its energy demand is naturally high. By using an energy recovery system, this demand can be lowered, leading to an energy demand per liter permeate of 3-4Wh/L only. Due to high iron levels in the groundwater and as a consequence the precipitation of ferric (hydr)oxides, it was necessary to develop a granular media filter for the trials under aeration in order to protect the membrane from clogging. Two different materials, first locally available sand, and second commercially available anthracite were tested in the granular media filter. For the trials with aerated groundwater, total arsenic removal efficiency at both locations was around 99% and the arsenic concentration in permeate was in compliance with the WHO and National Indian Standard of 10μg/L. However, trials under anoxic conditions with non-aerated groundwater could not comply with this standard. Additionally a possible safe discharge of the reverse osmosis concentrate into an abandoned well was studied. It was observed that re-injection of reject water underground may offer a safe disposal option. However, long

  2. METHODOLOGICAL APPROACH FOR MEASURING PRIORITY DBPS IN REVERSE OSMOSIS CONCENTRATED DRINKING WATER

    Science.gov (United States)

    Many disinfection by-products (DBPs) are formed when drinking water is chlorinated, but only a few are routinely measured or regulated. Various studies have revealed a plethora of DBPs for which sensitive and quantitative analytical methods have always been a major limiting facto...

  3. Lyophilization and Reconstitution of Reverse-Osmosis Concentrated Natural Organic Matter from a Drinking Water Source

    Science.gov (United States)

    Disinfection by-product (DBP) research can be complicated by difficulties in shipping large water quantities and changing natural organic matter (NOM) characteristics over time. To overcome these issues, it is advantageous to have a reliable method for concentrating NOM with min...

  4. Using microbial desalination cells to reduce water salinity prior to reverse osmosis

    KAUST Repository

    Mehanna, Maha; Saito, Tomonori; Yan, Jingling; Hickner, Michael; Cao, Xiaoxin; Huang, Xia; Logan, Bruce E.

    2010-01-01

    type of air-cathode MDC containing three equally sized chambers. A single cycle of operation using a 1 g L -1 acetate solution reduced the conductivity of salt water (5 g L-1 NaCl) by 43 ± 6%, and produced a maximum power density of 480 mW m-2 with a

  5. Evaluation of fertilizer-drawn forward osmosis for sustainable agriculture and water reuse in arid regions

    KAUST Repository

    Chekli, Laura; Kim, Youngjin; Phuntsho, Sherub; Li, Sheng; Ghaffour, NorEddine; Leiknes, TorOve; Shon, Ho Kyong

    2016-01-01

    to determine the effect of osmotic concentration of wastewater achieved in the FDFO process on the anaerobic activity. Results showed that 95% water recovery from the FDFO process is the optimum value for further AnMBR treatment. Nine different fertilizers were

  6. Application of forward osmosis technology in crude glycerol fermentation biorefinery-potential and challenges

    DEFF Research Database (Denmark)

    Kalafatakis, S.; Braekevelt, S.; Lymperatou, A.

    2018-01-01

    feedstock, without the need for an energy-intensive regeneration step (e.g. RO), has been investigated. Butanol production during crude glycerol fermentation by Clostridium pasteurianum, has been selected as a model process and the effect of cross-flow velocity and the dilution of draw solution on the water...... flux during short-term experiments (200 min), were investigated. Statistical analysis revealed that the dilution of the draw solution is the most influential factor for the water flux. Subsequent modelling of an integrated FO-fermentation process, showed that water recoveries could lead to substantial...... extensively studied; however, regeneration of the draw solution (thereby generating clean water) requires application of an energy-intensive process step like reverse osmosis (RO). In this study, the potential of applying FO for direct water recirculation from diluted fermentation effluent to concentrated...

  7. Osmosis-driven viscous fingering of oil-in-water emulsions

    Science.gov (United States)

    Liu, Ying; Rallabandi, Bhargav; Baskaran, Mrudhula; Stone, Howard

    2017-11-01

    Viscous fingering occurs when a low viscosity fluid invades a more viscous fluid. Fingering of two miscible fluids is more complicated than that of immiscible fluids in that there is no sharp fluid-fluid interface and diffusion occurs between the phases. We experimentally studied the fingering of two miscible fluids: an oil-in-water emulsion and a sodium chloride solution. When the concentration of sodium chloride in the water phase in the emulsion exceeds that in the sodium chloride solution, the consequent osmotic flow automatically facilitates the occurrence of the fingering. On the contrary, when the sodium chloride solution has higher concentration, the spreading of emulsion is more uniform than the case without the concentration difference. We provide a model to rationalize and quantify these observations.

  8. Synergistic efficiency of the desilication of brackish underground water in Saudi Arabia by coupling γ-radiation and Fenton process: Membrane scaling prevention in reverse osmosis process

    Science.gov (United States)

    Aljohani, Mohammed S.

    2017-12-01

    One of the main water resources in arid Saudi Arabia is underground water. However, this brackish water has high silica content which can cause a recalcitrant deposit on the membrane in the reverse osmosis units during its desalination. In this study, we examined the synergistic efficiency of the removal of silica from the Buwaib water sample, when combining two advanced oxidation processes, γ-irradiation and the Fenton process, using hydrogen peroxide and zero valent metal iron as source of Fe3+. This latter adsorbs effectively on silica and co-precipitate. The influence of absorbed dose, iron dosage and pH effect were investigated. This preliminary study showed that these attractive and effective hybrid processes are very efficient in removing silica.

  9. Forward osmosis - a novel membrane process for concentration of low level radioactive wastes

    International Nuclear Information System (INIS)

    Ghosh, A.K.; Bindal, R.C.; Tewari, P.K.

    2013-01-01

    Forward osmosis (FO) is an emerging membrane process in which osmotic pressure differential across a semi-permeable membrane between the solution to be concentrated (feed) and a concentrated solution of high osmotic pressure (draw solution) than the feed is used to effect separation of water from dissolved solutes. With time, feed stream gets concentrated with dilution of draw solution and this technology recently being used as more energy efficient alternative to reverse osmosis (RO) in some of the application areas, particularly for the concentration of low volume high value products. The use of pressure driven membrane processes like reverse osmosis (RO) and ultrafiltration (UF) are already demonstrated in the treatment of radioactive laundry, laboratory effluents and some other applications in nuclear industry. The application of FO membrane process to concentrate simulated inactive ammonium-diuranate (ADU) filtered effluent solution (by mixing uranyl nitrate and ammonium nitrate) using indigenously developed cellulose acetate (CA) and thin-film composite polyamide (TFCP) membranes has been published recently from our laboratory. In this presentation, we briefly discuss our views on possibility of using FO membrane process with proper selection of membrane for concentration of low level radioactive wastes generated in various steps of nuclear fuel cycle in most effective way. (author)

  10. Flux dependency of particulate/colloidal fouling in seawater reverse osmosis systems

    KAUST Repository

    Salinas Rodríguez, S. G.

    2012-01-01

    Fouling is the main operational problem in seawater reverse osmosis systems (SWRO). Particulate fouling is traditionally measured through the silt density index (SDI) and through the modified fouling index (MFI). In recent years, ultrafiltration membranes were used successfully at constant flux-MFI-UF-to measure particulate/colloidal fouling potential and tested in sea water applications. Furthermore, constant flux operation allows predicting the rate of fouling in RO systems. The objectives of this study are: (1) to measure the flux effect in MFI-UF with different membranes (100, 30 and 10 kDa) for raw seawater and pre-treated water before reverse osmosis in three different locations; (2) to study the particulate and colloidal fouling potential of seawater in reverse osmosis systems; (3) to project the increase in pressure due to cake resistance in reverse osmosis systems. In this research, flat ultrafiltration membranes (100, 50, 30 and 10 kDa) are used in a con- stant flux filtration mode to test and compare real seawaters from various locations (North and Mediterranean Sea) and from various full scale facilities including different pre-treatments (i.e., ultrafiltration and coagulation + dual media filtration). The operated fluxes range from 350 down to values close to real RO operation, 15l(m2h)-1. After each filtration test, the MFI-UF is calculated to assess the particulate fouling potential. The obtained results showed that: (1) the particulate and colloidal fouling potential is directly proportional to the applied flux during filtration. This proportionality is related to the compression of the cake deposit occurring at high flux values; (2) the higher the flux, the higher the required pressure, the less porous the cake and therefore the higher the specific cake resistance; (3) particulate and colloidal fouling potential of seawater is site specific and is influenced by pre-treatment. © 2012 Desalination Publications. All rights reserved.

  11. Compositions and constituents of freshwater dissolved organic matter isolated by reverse osmosis

    International Nuclear Information System (INIS)

    Zhang, Yulong; Huang, Wen; Ran, Yong; Mao, Jingdong

    2014-01-01

    Highlights: • Concentration factor controls sorption of DOM and thus yields of reverse osmosis. • Solid-state 13 C NMR was used to characterize RO-isolated DOM from freshwater. • C distribution of freshwater RO-DOM differs from that of reported marine DOM. • The compositions of DOM were transformed during transport from rivers to oceans. - Abstract: Dissolved organic matter (DOM) from riverine and lacustrine water was isolated using a reverse osmosis (RO) system. Solid-state 13 C nuclear magnetic resonance ( 13 C NMR) was used to quantitatively evaluate the compositions and constituents of DOM, which are compared with previous investigations on marine DOM. Results indicated that concentration factor (CF) was a key metric controlling yield and sorption of DOM on the RO system. The sorption was likely non-selective, based on the 13 C NMR and δ 13 C analyses. Carbohydrates and lipids accounted for 25.0–41.5% and 30.2–46.3% of the identifiable DOM, followed by proteins (18.2–19.8%) and lignin (7.17–12.8%). The freshwater DOM contained much higher alkyl and aromatic C but lower alkoxyl and carboxyl C than marine DOM. The structural difference was not completely accounted for by using structure of high molecular weight (HMW) DOM, suggesting a size change involved in transformations of DOM during the transport from rivers to oceans

  12. Isotope and ion selectivity in reverse osmosis desalination: geochemical tracers for man-made freshwater.

    Science.gov (United States)

    Kloppmann, Wolfram; Vengosh, Avner; Guerrot, Catherine; Millot, Romain; Pankratov, Irena

    2008-07-01

    A systematic measurement of ions and 2H/1H, 7Li/6Li, 11B/10B, 18O/ 16O, and 87Sr/86Sr isotopes in feed-waters, permeates, and brines from commercial reverse osmosis (RO) desalination plants in Israel (Ashkelon, Eilat, and Nitzana) and Cyprus (Larnaca) reveals distinctive geochemical and isotopic fingerprints of fresh water generated from desalination of seawater (SWRO) and brackish water (BWRO). The degree of isotope fractionation during the passage of water and solutes through the RO membranes depends on the medium (solvent-water vs. solutes), chemical speciation of the solutes, their charge, and their mass difference. O, H, and Sr isotopes are not fractionated during the RO process. 7Li is preferentially rejected in low pH RO, and B isotope fractionation depends on the pH conditions. Under low pH conditions, B isotopes are not significantly fractionated, whereas at high pH, RO permeates are enriched by 20 per thousand in 11B due to selective rejection of borate ion and preferential permeation of 11B-enriched boric acid through the membrane. The specific geochemical and isotopic fingerprints of SWRO provide a unique tool for tracing "man-made" fresh water as an emerging recharge component of natural water resources.

  13. The Modified Fouling Index Ultrafiltration constant flux for assessing particulate/colloidal fouling of RO systems

    KAUST Repository

    Salinas-Rodriguez, Sergio G.

    2015-02-18

    Reliable methods for measuring and predicting the fouling potential of reverse osmosis (RO) feed water are important in preventing and diagnosing fouling at the design stage, and for monitoring pre-treatment performance during plant operation. The Modified Fouling Index Ultrafiltration (MFI-UF) constant flux is a significant development with respect to assessing the fouling potential of RO feed water. This research investigates (1) the variables influencing the MFI-UF test at constant flux filtration (membrane pore size, membrane material, flux rate); and (2) the application of MFI-UF into pre-treatment assessment and RO fouling estimation. The dependency of MFI on flux, means that to assess accurately particulate fouling in RO systems, the MFI should be measured at a flux similar to a RO system (close to 20 L/m2/h) or extrapolated from higher fluxes. The two studied membrane materials showed reproducible results; 10% for PES membranes and 6.3% for RC membranes. Deposition factors (amount of particles that remain on the surface of membrane) were measured in a full-scale plant ranging between 0.2 and 0.5. The concept of “safe MFI” is presented as a guideline for assessing pre-treatment for RO systems.

  14. Reverse osmosis brine for phosphorus recovery from source separated urine.

    Science.gov (United States)

    Tian, Xiujun; Wang, Guotian; Guan, Detian; Li, Jiuyi; Wang, Aimin; Li, Jin; Yu, Zhe; Chen, Yong; Zhang, Zhongguo

    2016-12-01

    Phosphorus (P) recovery from waste streams has recently been recognized as a key step in the sustainable supply of this indispensable and non-renewable resource. The feasibility of using brine from a reverse osmosis (RO) membrane unit treating cooling water as a precipitant for P recovery from source separated urine was evaluated in the present study. P removal efficiency, process parameters and precipitate properties were investigated in batch and continuous flow experiments. More than 90% of P removal was obtained from both undiluted fresh and hydrolyzed urines by mixing with RO brine (1:1, v/v) at a pH over 9.0. Around 2.58 and 1.24 Kg of precipitates could be recovered from 1 m 3 hydrolyzed and fresh urine, respectively, and the precipitated solids contain 8.1-19.0% of P, 10.3-15.2% of Ca, 3.7-5.0% of Mg and 0.1-3.5% of ammonium nitrogen. Satisfactory P removal performance was also achieved in a continuous flow precipitation reactor with a hydraulic retention time of 3-6 h. RO brine could be considered as urinal and toilet flush water despite of a marginally higher precipitation tendency than tap water. This study provides a widely available, low - cost and efficient precipitant for P recovery in urban areas, which will make P recovery from urine more economically attractive. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. The pre-treatment of water in a reverse osmosis system. Its significant importance in the design and management of the process; Pretratamiento del agua en un sistema de osmosis inversa. Su significada importancia dentro del diseno y gestion del proceso

    Energy Technology Data Exchange (ETDEWEB)

    Pujadas, A.

    2001-07-01

    The practical application of reverse osmosis technology is really easy and facilities should function without serious problems. The real difficulty is presented by the pre-treatment and conditioning of water before entering the membrane system. The present article enumerates the series of most habitual problems presented by medium or low-saline water for its correct treatment in a reverse osmosis system, also enumerating the most habitual pre-treatments for overcoming them. The conclusion of all of this is that it is necessary to haven a good laboratory available, one that allows for a complete analysis of the water to be treated and a system for tracking the systems once they are in operation. (Author)

  16. Recovery of uranium by a reverse osmosis process

    International Nuclear Information System (INIS)

    Cleary, J.G.; Stana, R.R.

    1980-01-01

    A method for concentrating and recovering uranium material from an aqueous solution, comprises passing a feed solution containing uranium through at least one reverse osmosis membrane system to concentrate the uranium, and then flushing the concentrated uranium solution with water in a reverse osmosis membrane system to further concentrate the uranium

  17. Pilot-scale reverse osmosis testing for the F and H Area Effluent Treatment Facility

    International Nuclear Information System (INIS)

    Kessler, J.L.

    1984-01-01

    Pilot-scale reverse osmosis (RO) tests were completed with a 10 gpm unit to demonstrate the performance of RO in the F and H Area Effluent Treatment Facility (F/H ETF). RO will be used in the WMETF to remove soluble salts and soluble radioactivity. The advantage of using RO (over ion exchange) is that it is nondescriminanting and removes virtually all dissolved solids species, regardless of ionic charge. RO also generates less than half the waste volume produced by ion exchange. Test results using a 200-Area nonradioactive effluent simulant demonstrated salt rejections of 98% and water recoveries of 94% by using recycle on a single stage pilot unit. For a full-scale, multi-staged unit overall salt rejections will be 95% (DF = 20) while obtaining a 94% water recovery (94% discharge, 6% concentrated waste stream). Identical performance is expected on actual radioactive streams, based on shielded cells testing performed by Motyka and Stimson. Similarly, if the WMETF RO system is configured in the same manner as the SRL ECWPF, a DF of 20 and a water recvery of 94% should be obtained

  18. Forward Osmosis System And Process

    KAUST Repository

    Duan, Jintang

    2013-01-01

    A forward osmosis fluid purification system includes a cross-flow membrane module with a membrane, a channel on each side of the membrane which allows a feed solution and a draw solution to flow through separately, a feed side, a draw side including a draw solute, where the draw solute includes an aryl sulfonate salt. The system can be used in a process to extract water from impure water, such as wastewater or seawater. The purified water can be applied to arid land.

  19. Forward Osmosis System And Process

    KAUST Repository

    Duan, Jintang

    2013-08-22

    A forward osmosis fluid purification system includes a cross-flow membrane module with a membrane, a channel on each side of the membrane which allows a feed solution and a draw solution to flow through separately, a feed side, a draw side including a draw solute, where the draw solute includes an aryl sulfonate salt. The system can be used in a process to extract water from impure water, such as wastewater or seawater. The purified water can be applied to arid land.

  20. The use of reverse osmosis at nuclear power plants. Replacement of evaporator

    International Nuclear Information System (INIS)

    Kus, Pavel; Bartova, Sarka; Kunesova, Katerina; Smejdova, Vladena; Vonkova, Katerina

    2015-01-01

    Evaporators are being used in nuclear power plants for the treatment of primary coolant containing H3BO3 for neutron absorption and other components for adjusting water chemistry. The aim is to achieve a concentrated H3BO3 solution, which is further purified by ion exchangers and then recycled into the primary cycle. Operation of evaporators is expensive, therefore reverse osmosis was proposed as one promising alternative. A pilot-plant RO unit was used for the experiments performed with feed solution. The successful technology is now being implemented at Temelin NPP.

  1. The use of reverse osmosis at nuclear power plants. Replacement of evaporator

    Energy Technology Data Exchange (ETDEWEB)

    Kus, Pavel; Bartova, Sarka; Kunesova, Katerina; Smejdova, Vladena; Vonkova, Katerina [Research Centre Rez, Husinec-Rez (Czech Republic). Technological Circuits

    2015-06-01

    Evaporators are being used in nuclear power plants for the treatment of primary coolant containing H3BO3 for neutron absorption and other components for adjusting water chemistry. The aim is to achieve a concentrated H3BO3 solution, which is further purified by ion exchangers and then recycled into the primary cycle. Operation of evaporators is expensive, therefore reverse osmosis was proposed as one promising alternative. A pilot-plant RO unit was used for the experiments performed with feed solution. The successful technology is now being implemented at Temelin NPP.

  2. Evaluation of potential for reuse of industrial wastewater using metal-immobilized catalysts and reverse osmosis.

    Science.gov (United States)

    Choi, Jeongyun; Chung, Jinwook

    2015-04-01

    This report describes a novel technology of reusing the wastewater discharged from the display manufacturing industry through an advanced oxidation process (AOP) with a metal-immobilized catalyst and reverse osmosis (RO) in the pilot scale. The reclaimed water generated from the etching and cleaning processes in display manufacturing facilities was low-strength organic wastewater and was required to be recycled to secure a water source. For the reuse of reclaimed water to ultrapure water (UPW), a combination of solid-phase AOP and RO was implemented. The removal efficiency of TOC by solid-phase AOP and RO was 92%. Specifically, the optimal acid, pH, and H2O2 concentrations in the solid-phase AOP were determined. With regard to water quality and operating costs, the combination of solid-phase AOP and RO was superior to activated carbon/RO and ultraviolet AOP/anion polisher/coal carbon. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Membrane fouling and anti-fouling strategies using RO retentate from a municipal water recycling plant as the feed for osmotic power generation

    KAUST Repository

    Chen, Si Cong; Amy, Gary L.; Chung, Neal Tai-Shung

    2015-01-01

    RO retentate from a municipal water recycling plant is considered as a potential feed stream for osmotic power generation in this paper. The feasibility of using RO retentate from a municipal water recycling plant was examined from two aspects: (a) the membrane fouling propensity of RO retentate, and (b) the efficacy of anti-fouling strategies. The membranes used in this study were the inner selective thin film composite polyethersulfone (TFC/PES) hollow fiber membranes, which possessed a high water permeability and good mechanical strength. Scaling by phosphate salts was found to be one possible inorganic fouling on the innermost layer of the PES membrane, whereas silica fouling was observed to be the governing fouling on the outmost surface of the PES membrane. Two anti-fouling pretreatments, i.e., pH adjustment and anti-scalant pre-treatment for the feed stream, were studied and found to be straightforward and effective. Using RO retentate at pH 7.2 as the feed and 1 M NaCl as the draw solution, the average power density was 7.3 W/m at 20 bar. The average power density increased to 12.6 W/m by modifying RO retentate with an initial pH value of 5.5 using HCl and to 13.4 W/m by adding 1.1 mM ethylenediaminetetraacetic acid (EDTA). Moreover, the flux recovery of the fouled membranes, without the indicated pretreatments, reached 84.9% using deionized (DI) water flushing and 95.0% using air bubbling under a high crossflow velocity of 23.3 cm/s (Re = 2497) for 30 min. After pretreatment by pH adjustment, the flux recovery increased to 94.6% by DI water flushing and 100.0% by air bubbling. After pretreatment by adding 1.1 mM EDTA into RO retentate, flux was almost fully restored by physical cleaning by DI water flushing and air bubbling. These results provide insight into developing an effective pretreatment by either pH adjustment or EDTA addition before PRO and physical cleaning methods by DI water flushing and air bubbling for membrane used in osmotic power

  4. Membrane fouling and anti-fouling strategies using RO retentate from a municipal water recycling plant as the feed for osmotic power generation

    KAUST Repository

    Chen, Si Cong

    2015-10-25

    RO retentate from a municipal water recycling plant is considered as a potential feed stream for osmotic power generation in this paper. The feasibility of using RO retentate from a municipal water recycling plant was examined from two aspects: (a) the membrane fouling propensity of RO retentate, and (b) the efficacy of anti-fouling strategies. The membranes used in this study were the inner selective thin film composite polyethersulfone (TFC/PES) hollow fiber membranes, which possessed a high water permeability and good mechanical strength. Scaling by phosphate salts was found to be one possible inorganic fouling on the innermost layer of the PES membrane, whereas silica fouling was observed to be the governing fouling on the outmost surface of the PES membrane. Two anti-fouling pretreatments, i.e., pH adjustment and anti-scalant pre-treatment for the feed stream, were studied and found to be straightforward and effective. Using RO retentate at pH 7.2 as the feed and 1 M NaCl as the draw solution, the average power density was 7.3 W/m at 20 bar. The average power density increased to 12.6 W/m by modifying RO retentate with an initial pH value of 5.5 using HCl and to 13.4 W/m by adding 1.1 mM ethylenediaminetetraacetic acid (EDTA). Moreover, the flux recovery of the fouled membranes, without the indicated pretreatments, reached 84.9% using deionized (DI) water flushing and 95.0% using air bubbling under a high crossflow velocity of 23.3 cm/s (Re = 2497) for 30 min. After pretreatment by pH adjustment, the flux recovery increased to 94.6% by DI water flushing and 100.0% by air bubbling. After pretreatment by adding 1.1 mM EDTA into RO retentate, flux was almost fully restored by physical cleaning by DI water flushing and air bubbling. These results provide insight into developing an effective pretreatment by either pH adjustment or EDTA addition before PRO and physical cleaning methods by DI water flushing and air bubbling for membrane used in osmotic power

  5. Membrane fouling and anti-fouling strategies using RO retentate from a municipal water recycling plant as the feed for osmotic power generation.

    Science.gov (United States)

    Chen, Si Cong; Amy, Gary L; Chung, Tai-Shung

    2016-01-01

    RO retentate from a municipal water recycling plant is considered as a potential feed stream for osmotic power generation in this paper. The feasibility of using RO retentate from a municipal water recycling plant was examined from two aspects: (a) the membrane fouling propensity of RO retentate, and (b) the efficacy of anti-fouling strategies. The membranes used in this study were the inner selective thin film composite polyethersulfone (TFC/PES) hollow fiber membranes, which possessed a high water permeability and good mechanical strength. Scaling by phosphate salts was found to be one possible inorganic fouling on the innermost layer of the PES membrane, whereas silica fouling was observed to be the governing fouling on the outmost surface of the PES membrane. Two anti-fouling pretreatments, i.e., pH adjustment and anti-scalant pre-treatment for the feed stream, were studied and found to be straightforward and effective. Using RO retentate at pH 7.2 as the feed and 1 M NaCl as the draw solution, the average power density was 7.3 W/m(2) at 20 bar. The average power density increased to 12.6 W/m(2) by modifying RO retentate with an initial pH value of 5.5 using HCl and to 13.4 W/m(2) by adding 1.1 mM ethylenediaminetetraacetic acid (EDTA). Moreover, the flux recovery of the fouled membranes, without the indicated pretreatments, reached 84.9% using deionized (DI) water flushing and 95.0% using air bubbling under a high crossflow velocity of 23.3 cm/s (Re = 2497) for 30 min. After pretreatment by pH adjustment, the flux recovery increased to 94.6% by DI water flushing and 100.0% by air bubbling. After pretreatment by adding 1.1 mM EDTA into RO retentate, flux was almost fully restored by physical cleaning by DI water flushing and air bubbling. These results provide insight into developing an effective pretreatment by either pH adjustment or EDTA addition before PRO and physical cleaning methods by DI water flushing and air bubbling for membrane used in

  6. Removal of Inorganic, Microbial, and Particulate Contaminants from a Fresh Surface Water: Village Marine Tec. Expeditionary Unit Water Purifier, Generation 1

    Science.gov (United States)

    The Village Marine Tec. Generation 1 Expeditionary Unit Water Purifier (EUWP) is a mobile skid-mounted system employing ultrafiltration (UF) and reverse osmosis (RO) to produce drinking water from a variety of different water quality sources. The UF components were evaluated to t...

  7. Pressure retarded osmosis for energy production: membrane materials and operating conditions.

    Science.gov (United States)

    Kim, H; Choi, J-S; Lee, S

    2012-01-01

    Pressure retarded osmosis (PRO) is a novel membrane process to produce energy. PRO has the potential to convert the osmotic pressure difference between fresh water (i.e. river water) and seawater to electricity. Moreover, it can recover energy from highly concentrated brine in seawater desalination. Nevertheless, relatively little research has been undertaken for fundamental understanding of the PRO process. In this study, the characteristics of the PRO process were examined using a proof-of-concept device. Forward osmosis (FO), reverse osmosis (RO), and nanofiltration (NF) membranes were compared in terms of flux rate and concentration polarization ratio. The results indicated that the theoretical energy production by PRO depends on the membrane type as well as operating conditions (i.e. back pressure). The FO membrane had the highest energy efficiency while the NF membrane had the lowest efficiency. However, the energy production rate was low due to high internal concentration polarization (ICP) in the PRO membrane. This finding suggests that the control of the ICP is essential for practical application of PRO for energy production.

  8. REMOVAL OF CHEMICAL AND MICROBIAL CONTAMINANTS IN DRINKING WATER - WATTS PREMIER M-2400 POINT-OF-ENTRY REVERSE OSMOSIS DRINKINGWATER TREATMENT SYSTEM

    Science.gov (United States)

    The Watts Premier M-2400 POE RO Drinking Water Treatment System was tested at the NSF Drinking Water Treatment Systems Laboratory for removal of the viruses fr and MS2, the bacteria Brevundimonas diminuta, and chemicals aldicarb, benzene, cadmium, carbofuran, cesium, chl...

  9. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, REMOVAL OF ARSENIC IN DRINKING WATER: WATTS PREMIER M-SERIES M-15,000 REVERSE OSMOSIS TREATMENT SYSTEM

    Science.gov (United States)

    Verification testing of the Watts Premier M-Series M-15,000 RO Treatment System was conducted over a 31-day period from April 26, 2004, through May 26, 2004. This test was conducted at the Coachella Valley Water District (CVWD) Well 7802 in Thermal, California. The source water...

  10. Surface modification of seawater desalination reverse osmosis membranes: Characterization studies & performance evaluation

    KAUST Repository

    Matin, Asif

    2014-06-01

    In this work we report surface modification of commercial reverse osmosis membranes by depositing ultrathin copolymer coatings, which could potentially enhance the biofouling resistance of RO membranes. Hydrophilic monomer hydroxyethyl methacrylate (HEMA) and a hydrophobic monomer, perfluorodecyl acrylate (PFDA) were copolymerized directly on the active layer of commercial aromatic polyamide reverse osmosis (RO) membranes using an initiated Chemical Vapor Deposition (iCVD) technique. Attenuated total reflective Fourier transform infrared spectra (ATR-FTIR) verified the successful modification of the membrane surfaces as a new FTIR adsorption band around 1730cm-1 corresponding to carbonyl groups in the copolymer film appeared after the deposition. X-ray Photoelectron spectroscopy (XPS) analysis also confirmed the presence of the copolymer film on the membrane surface by showing strong fluorine peaks emanating from the fluorinated alkyl side chains of the PFA molecules. Contact angle measurements with deionized water showed the modified membrane surfaces to be initially very hydrophobic but quickly assumed a hydrophilic character within few minutes. Atomic Force Microscopy (AFM) revealed that the deposited films were smooth and conformal as the surface topology of the underlying membrane surface remained virtually unchanged after the deposition. FESEM images of the top surface also showed that the typical ridge-and-valley structure associated with polyamide remained intact after the deposition. Short-term permeation tests using DI water and 2000ppm NaCl water showed that the deposited copolymer coatings had negligible effect on permeate water flux and salt rejection. © 2013 Elsevier B.V.

  11. Modelamento of osmosis system reverse set in motion by a photovoltaic generator; Modelamento de sistema de osmose reversa acionado por um gerador fotovoltaico

    Energy Technology Data Exchange (ETDEWEB)

    Fraidenraich, N.; Vilela, O. C.; Lima, G. A.

    2008-07-01

    A theoretical model to study the operational conditions of Reverse Osmosis systems (RO) is presented. The model is applied to simulate the behavior of a Photovoltaic-Powered Reverse Osmosis System (PV-RO) monitored with sensors for measuring water flow, salinity, pressure voltage and current of operation. the system is powered by a PV generator with peak power of 0.81 kW. The interface of the PV generator and the motor-pump is a frequency converter, programmed to maintain the array working at a fixed voltage, chosen within the region of the maximum power. Considering the relation given by the load curve (pressure vs. feed flow rate) the permeated flow rate was determined theoretically for a given membrane length. The deviation between calculated and experimental results is smaller than 14.5%. The model can be used to determine parameters important in the sizing of those systems. (Author)

  12. Removal of Crotamiton from Reverse Osmosis Concentrate by a TiO2/Zeolite Composite Sheet

    Directory of Open Access Journals (Sweden)

    Qun Xiang

    2017-07-01

    Full Text Available Reverse osmosis (RO concentrate from wastewater reuse facilities contains concentrated emerging pollutants, such as pharmaceuticals. In this research, a paper-like composite sheet consisting of titanium dioxide (TiO2 and zeolite was synthesized, and removal of the antipruritic agent crotamiton from RO concentrate was studied using the TiO2/zeolite composite sheet. The RO concentrate was obtained from a pilot-scale municipal secondary effluent reclamation plant. Effective immobilization of the two powders in the sheet made it easy to handle and to separate the photocatalyst and adsorbent from purified water. The TiO2/zeolite composite sheet showed excellent performance for crotamiton adsorption without obvious inhibition by other components in the RO concentrate. With ultraviolet irradiation, crotamiton was simultaneously removed through adsorption and photocatalysis. The photocatalytic decomposition of crotamiton in the RO concentrate was significantly inhibited by the water matrix at high initial crotamiton concentrations, whereas rapid decomposition was achieved at low initial crotamiton concentrations. The major degradation intermediates were also adsorbed by the composite sheet. This result provides a promising method of mitigating secondary pollution caused by the harmful intermediates produced during advanced oxidation processes. The cyclic use of the HSZ-385/P25 composite sheet indicated the feasibility of continuously removing crotamiton from RO concentrate.

  13. Osmosis and thermodynamics explained by solute blocking.

    Science.gov (United States)

    Nelson, Peter Hugo

    2017-01-01

    A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult's law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed; others can be tested experimentally or by simulation.

  14. Osmosis and thermodynamics explained by solute blocking

    Science.gov (United States)

    Nelson, Peter Hugo

    2016-01-01

    A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult’s law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed, others can be tested experimentally or by simulation. PMID:27225298

  15. Understanding the risk of scaling and fouling in hollow fiber forward osmosis membrane application

    KAUST Repository

    Majeed, Tahir; Phuntsho, Sherub; Jeong, Sanghyun; Zhao, Yanxia; Gao, Baoyu; Shon, Ho Kyong

    2016-01-01

    Fouling studies of forward osmosis (FO) were mostly conducted based on fouling evaluation principals applied to pressure membrane processes such as reverse osmosis (RO)/nanofiltration (NF)/microfiltration (MF)/ultrafiltration (UF). For RO/NF/MF/UF processes, the single flux driving force (hydraulic pressure) remains constant, thus the fouling effect is easily evaluated by comparing flux data with the baseline. Whilst, the scenario of fouling effects for FO process is entirely different from RO/NF/MF/UF processes. Continuously changing driving force (osmotic pressure difference), the changes in concentration polarization associated with the varying draw solution/feed solution concentration and the fouling layer effects collectively influence the FO flux. Thus, usual comparison of the FO flux outcome with the baseline results can not exactly indicate the real affect of membrane fouling, rather presents a misleading cumulative effect. This study compares the existing FO fouling technique with an alternate fouling evaluation approach using two FO set-ups. Scaling and fouling risk for hollow fiber FO was separately investigated using synthetic water samples and model organic foulants as alginate, humic acid and bovine serum albumin. Results indicated that FO flux declines up to 5% and 49% in active layer-feed solution and active layer-draw solution orientations respectively.

  16. Understanding the risk of scaling and fouling in hollow fiber forward osmosis membrane application

    KAUST Repository

    Majeed, Tahir

    2016-06-23

    Fouling studies of forward osmosis (FO) were mostly conducted based on fouling evaluation principals applied to pressure membrane processes such as reverse osmosis (RO)/nanofiltration (NF)/microfiltration (MF)/ultrafiltration (UF). For RO/NF/MF/UF processes, the single flux driving force (hydraulic pressure) remains constant, thus the fouling effect is easily evaluated by comparing flux data with the baseline. Whilst, the scenario of fouling effects for FO process is entirely different from RO/NF/MF/UF processes. Continuously changing driving force (osmotic pressure difference), the changes in concentration polarization associated with the varying draw solution/feed solution concentration and the fouling layer effects collectively influence the FO flux. Thus, usual comparison of the FO flux outcome with the baseline results can not exactly indicate the real affect of membrane fouling, rather presents a misleading cumulative effect. This study compares the existing FO fouling technique with an alternate fouling evaluation approach using two FO set-ups. Scaling and fouling risk for hollow fiber FO was separately investigated using synthetic water samples and model organic foulants as alginate, humic acid and bovine serum albumin. Results indicated that FO flux declines up to 5% and 49% in active layer-feed solution and active layer-draw solution orientations respectively.

  17. Wastewater reclamation using discarded reverse osmosis membranes for reuse in irrigation in Djibouti, an arid country.

    Science.gov (United States)

    Awaleh, Mohamed Osman; Ahmed, Moussa Mahdi; Soubaneh, Youssouf Djibril; Hoch, Farhan Bouraleh; Bouh, Samatar Mohamed; Dirieh, Elias Said

    2013-01-01

    The purpose of this paper is to establish the feasibility of recovering discarded reverse osmosis (RO) membranes in order to reduce the salinity of domestic treated wastewater. This study shows that the reuse of RO membranes is of particular interest for arid countries having naturally high mineralized water such as Djibouti. The pilot desalination unit reduces the electrical conductivity, the turbidity and the total dissolved salt respectively at 75-85, 96.7 and 95.4%. The water produced with this desalination unit contains an average of 254 cfu/100 mL total coliforms and 87 cfu/100 mL fecal coliforms. This effluent meets the World Health Organization standards for treated wastewater reuse for agricultural purposes. The annual cost of the desalination unit was evaluated as US $/m(3) 0.82, indicating the relatively high cost of this process. Nevertheless, such processes are required to produce an effluent, with a high reuse potential.

  18. Troubleshooting at Reverse Osmosis performance decrease

    Energy Technology Data Exchange (ETDEWEB)

    Soons, Jan [KEMA (Netherlands)

    2011-07-01

    There are several causes for a decrease in Reverse Osmosis (RO) membrane performance each of which requiring actions to tackle the possible cause. Two of the main factors affecting the performance of the system are the feed quality (poor feed quality can lead to fouling of the membranes) and the operational conditions (including the maximum allowed pressure, minimum cleaning frequencies and types, recovery rate etc, which should be according to the design conditions). If necessary, pre-treatment will be applied in order to remove the fouling agents from the influent, reduce scaling (through the addition of anti-scalants) and for the protection of the membranes (for example, sodium metabisulphite addition for the removal of residual chlorine which can harm the membranes). Fouling is not strictly limited to the use of surface water as feed water, also relatively clean water sources will, over time, lead to organic and inorganic fouling when cleaning is not optimum. When fouling occurs, the TransMembrane Pressure (TMP) increases and more energy will be needed to produce the same amount of product water. Also, the cleaning rate will increase, reducing the production rate and increasing the chemical consumption and the produced waste streams. Furthermore, the quality of the effluent will decrease (lower rejection rates at higher pressures) and the lifetime of the membranes will decrease. Depending on the type of fouling different cleaning regimes will have to be applied: acidic treatment for inorganic fouling, the addition of bases against organic fouling. Therefore, it is very important to have a clear view of the type of fouling that is occurring, in order to apply the correct treatment methods. Another important aspect to be kept in mind is that the chemistry of the water - in the first place ruled by the feed water composition - can change during passage of the modules, in particular in cases where the RO system consists of two or more RO trains, and where the

  19. Osmotically and thermally isolated forward osmosis-membrane distillation (fo-md) integrated module for water treatment applications

    KAUST Repository

    Ghaffour, Noreddine

    2016-09-01

    An integrated forward osmosis-membrane distillation (FO-MD) module and systems and methods incorporating the module is disclosed providing higher efficiencies and using less energy. The FO-MD module is osmotically and thermally isolated. The isolation can prevent mixing of FO draw solution/FO permeate and MD feed, and minimize dilution of FO draw solution and cooling of MD feed. The module provides MD feed solution and FO draw solution streams that flow in the same module but are separated by an isolation barrier. The osmotically and thermally isolated FO-MD integrated module, systems and methods offer higher driving forces of both FO and MD processes, higher recovery, and wider application than previously proposed hybrid FO- MD systems.

  20. Osmotically and thermally isolated forward osmosis-membrane distillation (fo-md) integrated module for water treatment applications

    KAUST Repository

    Ghaffour, NorEddine; Francis, Lijo; Li, Zhenyu; Valladares, Rodrigo; Alsaadi, Ahmad S.; Ghdaib, Muhannad Abu; Amy, Gary L.

    2016-01-01

    An integrated forward osmosis-membrane distillation (FO-MD) module and systems and methods incorporating the module is disclosed providing higher efficiencies and using less energy. The FO-MD module is osmotically and thermally isolated. The isolation can prevent mixing of FO draw solution/FO permeate and MD feed, and minimize dilution of FO draw solution and cooling of MD feed. The module provides MD feed solution and FO draw solution streams that flow in the same module but are separated by an isolation barrier. The osmotically and thermally isolated FO-MD integrated module, systems and methods offer higher driving forces of both FO and MD processes, higher recovery, and wider application than previously proposed hybrid FO- MD systems.

  1. An experiment with spiral wound reverse osmosis membranes for the Desalination of seawater

    Directory of Open Access Journals (Sweden)

    M.N.A. Hawlader Hawlader,

    2017-11-01

    Full Text Available In the research, the performance characteristics of Reverse Osmosis (RO Spiral Wound (SW membrane are evaluated. The effects of feed water concentration, temperature, pressure and flow rate on the performance of this membrane are investigated. The product recovery ( of SW membrane is found to increase with feed water temperature and pressure, but decrease with increasing feed water concentration and flow rate. Salt passage (SP increases with feed water temperature and concentration, but decreases with increasing feed pressure and flow rate. Under the tested feed water conditions, of SW varies from 6% - 18% and permeate salinity is approximately 130ppm. In addition, validity of the Complete Mixing Model is verified and successfully extended to the derivation of water and salt transport parameters of SW membrane. Plots of I/SR' versus l/Jw display linear relationships, as predicted in the model.

  2. Novel Fouling-Reducing Coatings for Ultrafiltration, Nanofiltration, and Reverse Osmosis Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Benny Freeman

    2008-08-31

    Polymeric membranes could potentially be the most flexible and viable long-term strategy for treatment of produced water from oil and gas production. However, widespread use of membranes, including reverse osmosis (RO) membranes, for produced water purification is hindered due to fouling caused by the impurities present in the water. Fouling of RO membranes is likely caused by surface properties including roughness, hydrophilicity, and charge, so surface modification is the most widely considered approach to improve the fouling properties of current RO membranes. This project focuses on two main approaches to surface modification: coating and grafting. Hydrophilic coating and grafting materials based on poly(ethylene glycol) (PEG) are applied to commercial RO membranes manufactured by Dow FilmTec and GE. Crossflow filtration experiments are used to determine the fouling resistance of modified membranes, and compare their performance to that of unmodified commercial RO membranes. Grafting and coating are shown to be two alternative methods of producing modified membranes with improved fouling resistance.

  3. Evaluating the efficiency of different microfiltration and ultrafiltration membranes used as pretreatment for Red Sea water reverse osmosis desalination

    KAUST Repository

    Almashharawi, Samir; Ghaffour, NorEddine; Al-Ghamdi, M.; Amy, Gary L.

    2013-01-01

    consistent silt density index, coagulation control at low total suspended solids, and management of higher waste sludge. Recently, there has been a rapid growth in the use of low-pressure membranes as pretreatment for RO systems replacing the conventional

  4. Seawater reverse osmosis desalination and (harmful) algal blooms

    KAUST Repository

    Villacorte, Loreen O.; Tabatabai, S. Assiyeh Alizadeh; Anderson, Donald M.; Amy, Gary L.; Schippers, Jan Cornelis; Kennedy, Maria Dolores

    2015-01-01

    This article reviews the occurrence of HABs in seawater, their effects on the operation of seawater reverse osmosis (SWRO) plants, the indicators for quantifying/predicting these effects, and the pretreatment strategies for mitigating operational issues during algal blooms. The potential issues in SWRO plants during HABs are particulate/organic fouling of pretreatment systems and biological fouling of RO membranes, mainly due to accumulation of algal organic matter (AOM). The presence of HAB toxins in desalinated water is also a potential concern but only at very low concentrations. Monitoring algal cell density, AOM concentrations and membrane fouling indices is a promising approach to assess the quality of SWRO feedwater and performance of the pretreatment system. When geological condition is favourable, subsurface intake can be a robust pretreatment for SWRO during HABs. Existing SWRO plants with open intake and are fitted with granular media filtration can improve performance in terms of capacity and product water quality, if preceded by dissolved air flotation or sedimentation. However, the application of advanced pretreatment using ultrafiltration membrane with in-line coagulation is often a better option as it is capable of maintaining stable operation and better RO feed water quality during algal bloom periods with significantly lower chemical consumption.

  5. Seawater reverse osmosis desalination and (harmful) algal blooms

    KAUST Repository

    Villacorte, Loreen O.

    2015-03-01

    This article reviews the occurrence of HABs in seawater, their effects on the operation of seawater reverse osmosis (SWRO) plants, the indicators for quantifying/predicting these effects, and the pretreatment strategies for mitigating operational issues during algal blooms. The potential issues in SWRO plants during HABs are particulate/organic fouling of pretreatment systems and biological fouling of RO membranes, mainly due to accumulation of algal organic matter (AOM). The presence of HAB toxins in desalinated water is also a potential concern but only at very low concentrations. Monitoring algal cell density, AOM concentrations and membrane fouling indices is a promising approach to assess the quality of SWRO feedwater and performance of the pretreatment system. When geological condition is favourable, subsurface intake can be a robust pretreatment for SWRO during HABs. Existing SWRO plants with open intake and are fitted with granular media filtration can improve performance in terms of capacity and product water quality, if preceded by dissolved air flotation or sedimentation. However, the application of advanced pretreatment using ultrafiltration membrane with in-line coagulation is often a better option as it is capable of maintaining stable operation and better RO feed water quality during algal bloom periods with significantly lower chemical consumption.

  6. Reverse osmosis for the recovery of boric acid from the primary coolant at nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Bártová, Šárka, E-mail: sarka.bartova@cvrez.cz [Research Centre Řež Ltd., Husinec-Řež 130, 250 68 Řež (Czech Republic); Kůs, Pavel [Research Centre Řež Ltd., Husinec-Řež 130, 250 68 Řež (Czech Republic); Skala, Martin [Research Centre Řež Ltd., Husinec-Řež 130, 250 68 Řež (Czech Republic); University of Chemical Technology, Prague, Department of Chemical Engineering, Technická 5, Prague 166 28 (Czech Republic); Vonková, Kateřina [Research Centre Řež Ltd., Husinec-Řež 130, 250 68 Řež (Czech Republic)

    2016-04-15

    Highlights: • RO membranes tested for boric acid recovery from primary coolant of nuclear power plants. • Scanning electron microscopy was used for the characterization of the membranes. • Lab scale experiments performed under various operation conditions. • We proposed configuration of and operation conditions for RO unit in nuclear power plant. - Abstract: At nuclear power plants (NPP), evaporators are used for the treatment of primary coolant and other liquid radioactive waste containing H{sub 3}BO{sub 3}. Because the operation of evaporators is expensive, a number of more cost-effective alternatives has been considered, one of which is reverse osmosis. We tested reverse osmosis modules from several manufactures on a batch laboratory apparatus. SEM images of the tested membranes were taken to distinguish the differences between the membranes. Water permeability through membranes was evaluated from the experiments with pure water. The experiments were performed with feed solutions containing various concentrations of H{sub 3}BO{sub 3} in a range commonly occurring in radioactive waste. The pH of the feed solutions ranged from 5.2 to 11.2. Our results confirmed that the pH of the feed solution plays the most important role in membrane separation efficiency of H{sub 3}BO{sub 3}. Certain modifications to the pH of the feed solution were needed to enable the tested membranes to concentrate the H{sub 3}BO{sub 3} in the retentate stream, separate from the pure water in the permeate stream. On this basis, we propose the configuration of and operational conditions for a reverse osmosis unit at NPP.

  7. Heavy metal removal using reverse osmosis

    Directory of Open Access Journals (Sweden)

    Lucia Gajdošová

    2009-12-01

    Full Text Available The aim of this work was to study reverse osmosis characteristics for copper, nickel and zinc removal from technological aqueoussolutions. Reverse osmosis (RO is a separation process that uses pressure to force a solution through a membrane that retainsthe solute on one side and allows the pure solvent to pass to the other side. A polyamide thin-film composite membrane TW30-1812-50was used. The difference in flux decline is significant. There is a significant difference in flux decline depending on the anions of usedheavy metal salts. The heavy metal concentration also has a significant influence on the membrane separation. There is alsoa significant difference in flux decline depending on the transmembrane pressure.

  8. Effectiveness of household reverse-osmosis systems in a Western U.S. region with high arsenic in groundwater

    International Nuclear Information System (INIS)

    Walker, Mark; Seiler, Ralph L.; Meinert, Michael

    2008-01-01

    It is well known to the public in Lahontan Valley in rural Nevada, USA, that local aquifers produce water with varied, but sometimes very high concentrations of arsenic (> 4 ppm). As a result, many residents of the area have installed household reverse-osmosis (RO) systems to produce drinking water. We examined performance of RO systems and factors associated with arsenic removal efficiency in 59 households in Lahontan Valley. The sampling results indicated that RO systems removed an average of 80.2% of arsenic from well water. In 18 of the 59 households, arsenic concentrations exceeded 10 ppb in treated water, with a maximum in treated water of 180 ppb. In 3 of the 59 households, RO treatment had little effect on specific conductance, indicating that the RO system was not working properly. Two main factors lead to arsenic levels in treated water exceeding drinking-water standards in the study area. First, arsenic concentrations were high enough in some Lahontan Valley wells that arsenic levels exceeded 10 ppb even though RO treatment removed more than 95% of the arsenic. Second, trivalent As +3 was the dominant arsenic species in approximately 15% of the wells, which significantly reduced treatment efficiency. Measurements of specific conductance indicated that efficiency in reducing arsenic levels did not always correlate with reductions in total dissolved solids. As a consequence, improvements in taste of the water or simple measurements of specific conductance made by technicians to test RO systems can mislead the public into assuming the water meets safety standards. Actual measurements of treated water are necessary to assure that household RO systems are reducing arsenic concentrations to safe levels, particularly in areas where groundwater has high arsenic concentrations or where As +3 is the dominant species

  9. Simulation and design of multi-stage demineralisation processes by using reverse osmosis and ion exchanger; Simulation und Auslegung mehrstufiger Wasser-Entsalzungsprozesse unter Einsatz von Umkehrosmose und Ionenaustausch

    Energy Technology Data Exchange (ETDEWEB)

    Lipnizki, Jens; Dinges, Bjoern; Schaberger, Heinz [Lanxess Deutschland GmbH, Leverkusen (Germany)

    2013-09-01

    Simulation and design of both reverse osmosis (RO) and ion exchange (IEX) processes for water demineralisation are supported by the user-friendly, integrated software LewaPlus trademark. This new software offers the option to design complex water treatment solutions, and provides the possibility to directly compare the results of RO and IEX calculations. It is possible to calculate with a given water analysis the results of RO treatment, and of subsequent treatment of this water with RO or IEX, respectively. The effect of variables such as temperature, silica, and carbonate concentration in the feed on process design and final water quality can be calculated for a whole system. The paper gives an overview of the capabilities of the software package and presents several application examples. (orig.)

  10. Osmosis and Surface Area to Volume Ratio.

    Science.gov (United States)

    Barrett, D. R. B.

    1984-01-01

    Describes an experiment designed to help students understand the concepts of osmosis and surface area to volume ratio (SA:VOL). The task for students is to compare water uptake in different sizes of potato cubes and relate differences to their SA:VOL ratios. (JN)

  11. Biofilm Formation on Reverse Osmosis Membranes Is Initiated and Dominated by Sphingomonas spp.▿ †

    Science.gov (United States)

    Bereschenko, L. A.; Stams, A. J. M.; Euverink, G. J. W.; van Loosdrecht, M. C. M.

    2010-01-01

    The initial formation and spatiotemporal development of microbial biofilm layers on surfaces of new and clean reverse osmosis (RO) membranes and feed-side spacers were monitored in situ using flow cells placed in parallel with the RO system of a full-scale water treatment plant. The feed water of the RO system had been treated by the sequential application of coagulation, flocculation, sand filtration, ultrafiltration, and cartridge filtration processes. The design of the flow cells permitted the production of permeate under cross-flow conditions similar to those in spiral-wound RO membrane elements of the full-scale system. Membrane autopsies were done after 4, 8, 16, and 32 days of flow-cell operation. A combination of molecular (fluorescence in situ hybridization [FISH], denaturing gradient gel electrophoresis [DGGE], and cloning) and microscopic (field emission scanning electron, epifluorescence, and confocal laser scanning microscopy) techniques was applied to analyze the abundance, composition, architecture, and three-dimensional structure of biofilm communities. The results of the study point out the unique role of Sphingomonas spp. in the initial formation and subsequent maturation of biofilms on the RO membrane and feed-side spacer surfaces. PMID:20190090

  12. Continuous processing of Aloe Vera juice in Reverse Osmosis integrated plant

    International Nuclear Information System (INIS)

    Nasim, H.; Younas, M.; Feroz, N.; Swati, I.K.

    2012-01-01

    Membrane technology is being applied in the food and beverages industry particularly in fruit juice concentration all over the world. The major advantages are lesser use of energy, better taste of products, and recovery of pure aroma/flavor and ease of operation. The current study is focused on the experimental investigation of clarification and concentration of Aloe juice through membrane separation technique. The experimental procedure consists of Aloe gel followed by pulping, a clarification by filtration and the concentration by reverse osmosis (RO). Experimental rig was integrated with spiral wound TFM-50 membrane, pre-treatment filters, pumps, rota meter and pressure sensors. The effect of feed pressure and temperature was studied on the dynamic behavior of RO integrated plant for water removal and permeate flux. It was found that Aloe juice was concentrated at optimum pressure and temperature of 40 bar and 40 degree C, respectively. (author)

  13. Hybrid membrane system for desalination and wastewater treatment : Integrating forward osmosis and low pressure reverse osmosis

    NARCIS (Netherlands)

    Valladares Linares, R.

    2014-01-01

    Since more than 97% of the water in the world is seawater, desalination technologies have the potential to solve the fresh water crisis. The most used desalination technology nowadays is seawater reverse osmosis (SWRO), where a membrane is used as a physical barrier to separate the salts from the

  14. Biochar-based constructed wetlands to treat reverse osmosis rejected concentrates in chronic kidney disease endemic areas in Sri Lanka.

    Science.gov (United States)

    Athapattu, B C L; Thalgaspitiya, T W L R; Yasaratne, U L S; Vithanage, Meththika

    2017-12-01

    The objectives were to investigate the potential remedial measures for reverse osmosis (RO) rejected water through constructed wetlands (CWs) with low-cost materials in the media established in chronic kidney disease of unknown etiology (CKDu) prevalent area in Sri Lanka. A pilot-scale surface and subsurface water CWs were established at the Medawachchiya community-based RO water supply unit. Locally available soil, calicut tile and biochar were used in proportions of 81, 16.5 and 2.5% (w/w), respectively, as filter materials in the subsurface. Vetiver grass and Scirpus grossus were selected for subsurface wetland while water lettuce and water hyacinth were chosen for free water surface CWs. Results showed that the CKDu sensitive parameters; total dissolved solids, hardness, total alkalinity and fluoride were reduced considerably (20-85%) and most met desirable levels of stipulated ambient standards. Biochar seemed to play a major role in removing fluoride from the system which may be due to the existing and adsorbed K + , Ca +2 , Mg +2 , etc. on the biochar surface via chemisorption. The least reduction was observed for alkalinity. This study indicated potential purification of aforesaid ions in water which are considerably present in RO rejection. Therefore, the invented bio-geo constructed wetland can be considered as a sustainable, economical and effective option for reducing high concentrations of CKDu sensitive parameters in RO rejected water before discharging into the inland waters.

  15. Integrating microbial fuel cells with anaerobic acidification and forward osmosis membrane for enhancing bio-electricity and water recovery from low-strength wastewater.

    Science.gov (United States)

    Liu, Jinmeng; Wang, Xinhua; Wang, Zhiwei; Lu, Yuqin; Li, Xiufen; Ren, Yueping

    2017-03-01

    Microbial fuel cells (MFCs) and forward osmosis (FO) are two emerging technologies with great potential for energy-efficient wastewater treatment. In this study, anaerobic acidification and FO membrane were simultaneously integrated into an air-cathode MFC (AAFO-MFC) for enhancing bio-electricity and water recovery from low-strength wastewater. During a long-term operation of approximately 40 days, the AAFO-MFC system achieved a continuous and relatively stable power generation, and the maximum power density reached 4.38 W/m 3 . The higher bio-electricity production in the AAFO-MFC system was mainly due to the accumulation of ethanol resulted from anaerobic acidification process and the rejection of FO membrane. In addition, a proper salinity environment in the system controlled by the addition of MF membrane enhanced the electricity production. Furthermore, the AAFO-MFC system produced a high quality effluent, with the removal rates of organic matters and total phosphorus of more than 97%. However, the nitrogen removal was limited for the lower rejection of FO membrane. The combined biofouling and inorganic fouling were responsible for the lower water flux of FO membrane, and the Desulfuromonas sp. utilized the ethanol for bio-electricity production was observed in the anode. These results substantially improve the prospects for simultaneous wastewater treatment and energy recovery, and further studies are needed to optimize the system integration and operating parameters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. ETV REPORT: REMOVAL OF CHEMICAL CONTAMINANTS IN DRINKING WATER – WATTS PREMIER INC. WP-4V DRINKING WATER TREATMENT SYSTEM

    Science.gov (United States)

    The Watts Premier WP-4V POU drinking water treatment system was tested for removal of aldicarb, benzene, cadmium, carbofuran, cesium, chloroform, dichlorvos, dicrotophos, fenamiphos, mercury, mevinphos, oxamyl, strontium, and strychnine. The WP-4V employs a reverse osmosis (RO) m...

  17. Combined solar organic Rankine cycle with reverse osmosis desalination process: Energy, exergy, and cost evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Nafey, A.S.; Sharaf, M.A. [Department of Engineering Science, Faculty of Petroleum and Mining Engineering, Suez Canal University, Suez (Egypt)

    2010-11-15

    Organic Rankine cycles (ORC) have unique properties that are well suited to solar power generation. In this work design and performance calculations are performed using MatLab/SimuLink computational environment. The cycle consists of thermal solar collectors (Flat Plate Solar Collector (FPC), or Parabolic Trough Collector (PTC), or Compound Parabolic Concentrator (CPC)) for heat input, expansion turbine for work output, condenser unit for heat rejection, pump unit, and Reverse Osmosis (RO) unit. Reverse osmosis unit specifications used in this work is based on Sharm El-Shiekh RO desalination plant. Different working fluids such as: butane, isobutane, propane, R134a, R152a, R245ca, and R245fa are examined for FPC. R113, R123, hexane, and pentane are investigated for CPC. Dodecane, nonane, octane, and toluene are allocated for PTC. The proposed process units are modeled and show a good validity with literatures. Exergy and cost analysis are performed for saturation and superheated operating conditions. Exergy efficiency, total exergy destruction, thermal efficiency, and specific capital cost are evaluated for direct vapor generation (DVG) process. Toluene and Water achieved minimum results for total solar collector area, specific total cost and the rate of exergy destruction. (author)

  18. Online monitoring of N-nitrosodimethylamine rejection as a performance indicator of trace organic chemical removal by reverse osmosis.

    Science.gov (United States)

    Fujioka, Takahiro; Takeuchi, Haruka; Tanaka, Hiroaki; Kodamatani, Hitoshi

    2018-06-01

    The security of recycled water quality in potable reuse can be enhanced by improving the credibility of reverse osmosis (RO) treatment for the removal of trace organic chemicals (TOrCs). This study evaluated the potential of online monitoring of N-nitrosodimethylamine (NDMA) before and after RO treatment as a surrogate indicator for TOrC removal by RO. This pilot-scale study monitored NDMA concentrations in RO feedwater (ultrafiltration-treated wastewater) and RO permeate every 22 min using novel online NDMA analyzers-high-performance liquid chromatography followed by photochemical reaction and chemiluminescence detection. NDMA rejection by RO varied considerably in response to changes in operating conditions (permeate flux and feedwater temperature). A high linear correlation between NDMA rejection and the rejection of six other TOrCs was observed. The linear correlation was also identified for an RO membrane damaged with chlorine. The correlation between another potential surrogate indicator (conductivity rejection) and TOrC rejection was relatively low. NDMA, which is the smallest compound among regulated TOrCs, revealed rejections lower than the other TOrCs, indicating that NDMA rejection can be a conservative surrogate indicator capable of predicting changes in TOrC removal. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Osmosis and Diffusion

    Science.gov (United States)

    Sack, Jeff

    2005-01-01

    OsmoBeaker is a CD-ROM designed to enhance the learning of diffusion and osmosis by presenting interactive experimentation to the student. The software provides several computer simulations that take the student through different scenarios with cells, having different concentrations of solutes in them.

  20. Evaluating the Efficiency of Different Microfiltration and Ultrafiltration Membranes Used as Pre-treatment for Reverse Osmosis Desalination of Red Sea Water

    KAUST Repository

    AlMashharawi, Samer

    2011-07-01

    . Collectively, results showed that all eight configurations provided permeate with excellent water quality to be fed to reverse osmosis membrane. However, using the 0.1 μm and 100kDa membranes with 1 mg/l FeCl3 concentration, respectively, steadier fluxes correspond to less increment of pumping intensity and better water quality was achieved.

  1. A Mechanistic Study of Arsenic (III) Rejection by Reverse Osmosis and Nanofiltration Membranes

    Science.gov (United States)

    Suzuki, Tasuma

    2009-01-01

    Reverse osmosis/nanofiltration (RO/NF) membranes are capable to provide an effective barrier for a wide range of contaminants (including disinfection by-products precursors) in a single treatment step. However, solute rejection mechanisms by RO/NF membranes are not well understood. The lack of mechanistic information arises from experimental…

  2. Reverse osmosis separation of radium from dilute aqueous solutions

    International Nuclear Information System (INIS)

    Subramanian, K.S.; Sastri, V.S.

    1980-01-01

    Porous cellulose acetate membranes obtained from Osmonics Inc. were characterized in terms of pure water permeability constant, solute transport parameter, and mass transfer coefficient with aqueous sodium chloride solution as the reference system. Reverse osmosis separation behavior of radium-226 as nitrate, chloride, and sulfate salts was studied. Reverse osmosis method of removing radium-226 from aqueous solutions has been compared with other methods, and it has been shown to be one of the best methods for alleviating radium contamination problems

  3. Hydrophilic, bactericidal nanoheater-enabled reverse osmosis membranes to improve fouling resistance.

    Science.gov (United States)

    Ray, Jessica R; Tadepalli, Sirimuvva; Nergiz, Saide Z; Liu, Keng-Ku; You, Le; Tang, Yinjie; Singamaneni, Srikanth; Jun, Young-Shin

    2015-06-03

    Polyamide (PA) semipermeable membranes typically used for reverse osmosis water treatment processes are prone to fouling, which reduces the amount and quality of water produced. By synergistically coupling the photothermal and bactericidal properties of graphene oxide (GO) nanosheets, gold nanostars (AuNS), and hydrophilic polyethylene glycol (PEG) on PA reverse osmosis membrane surfaces, we have dramatically improved fouling resistance of these membranes. Batch fouling experiments from three classes of fouling are presented: mineral scaling (CaCO3 and CaSO4), organic fouling (humic acid), and biofouling (Escherichia coli). Systematic analyses and a variety of complementary techniques were used to elucidate fouling resistance mechanisms from each layer of modification on the membrane surface. Both mineral scaling and organic fouling were significantly reduced in PA-GO-AuNS-PEG membranes compared to other membranes. The PA-GO-AuNS-PEG membrane was also effective in killing all near-surface bacteria compared to PA membranes. In the PA-GO-AuNS-PEG membrane, the GO nanosheets act as templates for in situ AuNS growth, which then facilitated localized heating upon irradiation by an 808 nm laser inactivating bacteria on the membrane surface. Furthermore, AuNS in the membrane assisted PEG in preventing mineral scaling on the membrane surface. In flow-through flux and foulant rejection tests, PA-GO-AuNS-PEG membranes performed better than PA membranes in the presence of CaSO4 and humic acid model foulants. Therefore, the newly suggested membrane surface modifications will not only reduce fouling from RO feeds, but can improve overall membrane performance. Our innovative membrane design reported in this study can significantly extend the lifetime and water treatment efficacy of reverse osmosis membranes to alleviate escalating global water shortage from rising energy demands.

  4. Technical feasibility of reuse of effluent generated from reverse osmosis system in a pharmaceutical plant

    Directory of Open Access Journals (Sweden)

    Bárbara de A. S. de Andrade

    2017-09-01

    Full Text Available Reuse reduces the consumption of freshwater supplies and the negative environmental impact caused by the discharge of industrial effluents. Some industries have already adopted this practice; however, no studies were found in the literature regarding this subject in the pharmaceutical industry. This work investigated the potential reuse of effluent (concentrate generated from the Reverse Osmosis/Electro-deionization System (RO/EDI that is used for the production of purified water in a Brazilian pharmaceutical plant. This industrial complex consumed about 200,000 m3 of water per year between 2012 and 2013 to produce one million of doses of vaccines, i.e., 2 L of water per dose of vaccine produced. During this period, the RO/EDI produced 27,000 m3 of purified water annually and generated 24,000 m3 of effluent (concentrate. This amount of effluent could be used to supply the production of industry steam (boilers and/or cold water (cooling towers that annually consumed an average of 12,000 m3 and 40,000 m3, respectively. The reuse of this effluent would result in a gross financial savings of 96,000 USD per year, excluding the costs of installation and control. From what has been researched in the literature, this work showed for the first time the possibility of reuse of effluent from RO/EDI System in the pharmaceutical industry.

  5. Two-step optimization of pressure and recovery of reverse osmosis desalination process.

    Science.gov (United States)

    Liang, Shuang; Liu, Cui; Song, Lianfa

    2009-05-01

    Driving pressure and recovery are two primary design variables of a reverse osmosis process that largely determine the total cost of seawater and brackish water desalination. A two-step optimization procedure was developed in this paper to determine the values of driving pressure and recovery that minimize the total cost of RO desalination. It was demonstrated that the optimal net driving pressure is solely determined by the electricity price and the membrane price index, which is a lumped parameter to collectively reflect membrane price, resistance, and service time. On the other hand, the optimal recovery is determined by the electricity price, initial osmotic pressure, and costs for pretreatment of raw water and handling of retentate. Concise equations were derived for the optimal net driving pressure and recovery. The dependences of the optimal net driving pressure and recovery on the electricity price, membrane price, and costs for raw water pretreatment and retentate handling were discussed.

  6. INFLUENCE AT DIFFERENT OPERATION CONDITIONS ON THE ACEROLA JUICE CONCENTRATION BY REVERSE OSMOSIS, USING SPIRAL MEMBRANE OF COMPOSITE FILM

    Directory of Open Access Journals (Sweden)

    E. R.S. GOMES

    2009-03-01

    Full Text Available

    The concentration of acerola juice, involves removal of water with the objective of reducing packing, storage and transport costs. The reverse osmosis (RO is a process of increasing interest in food industry and among the advantages they stand out: the low consumption of energy and the minimum thermal damages is caused to the products. The objective of this work was to evaluate the influence of different operation conditions in relation to the permeate flux, in the concentration process of the acerola juice by RO. All the RO experiments were carried out with retentate recycling. The concentration by RO, were carried on the transmembrane pressures of 20, 30 and 40 bar and at 23ºC and 40ºC, being used a membrane of composite film in spiral module (99% NaCl rejection. The acerola pulp was defrosted and treated with Citrozym Ultra L enzyme (100 ppm, 45ºC ,1 hour, then it was ultrafiltrated at 3 bar at the same temperature, in 0.1 µm ceramic membrane, and so it was concentrated by RO. It was verified that the pressure and the temperature influenced the concentration and the permeate flux obtained in the RO process. The flux decreased along the processing, once the feeding becomes more concentrate, increasing the viscosity, osmotic pressure and retained sugar. KEYWORDS: Acerola juice concentration; reverse osmosis; membrane of composite film.

  7. Reverse osmosis desalination of chitosan cross-linked graphene oxide/titania hybrid lamellar membranes.

    Science.gov (United States)

    Deng, Hui; Sun, Penzhan; Zhang, Yingjiu; Zhu, Hongwei

    2016-07-08

    With excellent mass transport properties, graphene oxide (GO)-based lamellar membranes are believed to have great potential in water desalination. In order to quantify whether GO-based membranes are indeed suitable for reverse osmosis (RO) desalination, three sub-micrometer thick GO-based lamellar membranes: GO-only, reduced GO (RGO)/titania (TO) nanosheets and RGO/TO/chitosan (CTS) are prepared, and their RO desalination performances are evaluated in a home-made RO test apparatus. The photoreduction of GO by TO improves the salt rejection, which increases slowly with the membrane thickness. The RGO/TO/CTS hybrid membranes exhibit higher rejection rates of only about 30% (greater than threefold improvement compared with a GO-only membrane) which is still inferior compared to other commercial RO membranes. The low rejection rates mainly arise from the pressure-induced weakening of the ion-GO interlayer interactions. Despite the advantages of simple, low-cost preparation, high permeability and selectivity of GO-based lamellar membranes, as the current desalination performances are not high enough to afford practical application, there still remains a great challenge to realize high performance separation membranes for water desalination applications.

  8. Development of ultra-low pressure reverse osmosis membranes; Choteiatsu gyakushintomaku no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, M.; Ito, H.; Ohara, T. [Nitto Denko Corp., Osaka (Japan)

    1998-06-05

    Described herein is development of ultra-low pressure reverse osmosis (RO) membranes. The composite RO membrane, which is now widely used, has a cross-sectional structure consisting of an ultrafilter membrane as the support and a very thin skin layer responsible for filtration. It is confirmed that the skin layer is of a pleated structure. Growing this structure can greatly accelerate permeation of water without damaging arresting and durability characteristics of the membrane, and hence is a desired approach. Utilization of molecular structure simulation of the skin layer materials is investigated by the molecular dynamics. The results show that the stable structure of the material for the skin layer in the RO membrane is a network structure with regularly arranged honeycombs, when it should arrest at least 99% of salt. These techniques serve as the bases for development of the ultra-low pressure RO membranes (ES Series), where the skin layer is made of cross-linked, totally aromatic polyamide. The membrane passes twice as large a quantity of water as the conventional one, is highly resistant to chemicals, and arrests 99.7% of salt. 3 refs., 4 figs.

  9. Anti-fouling and high water permeable forward osmosis membrane fabricated via layer by layer assembly of chitosan/graphene oxide

    Science.gov (United States)

    Salehi, Hasan; Rastgar, Masoud; Shakeri, Alireza

    2017-08-01

    To date, forward osmosis (FO) has received considerable attention due to its potential application in seawater desalination. FO does not require external hydraulic pressure and consequently is believed to have a low fouling propensity. Despite the numerous privileges of FO process, a major challenge ahead for its development is the lack of high performance membranes. In this study, we fabricated a novel highly-efficient FO membrane using layer-by-layer (LbL) assembly of positive chitosan (CS) and negative graphene oxide (GO) nanosheets via electrostatic interaction on a porous support layer. The support layer was prepared by blending hydrophilic sulfonated polyethersulfone (SPES) into polyethersulfone (PES) matrix using wet phase inversion process. Various characterization techniques were used to confirm successful fabrication of LbL membrane. The number of layers formed on the SPES-PES support layer was easily adjusted by repeating the CS and GO deposition cycles. Thin film composite (TFC) membrane was also prepared by the same SPES-PES support layer and polyamide (PA) active layer to compare membranes performances. The water permeability and salt rejection of the fabricated membranes were obtained by two kinds of draw solutions (including Na2SO4 and sucrose) under two different membrane orientations. The results showed that membrane coated by a CS/GO bilayers had water flux of 2-4 orders of magnitude higher than the TFC one. By increasing the number of CS/GO bilayers, the selectivity of the LbL membrane was improved. The novel fabricated LbL membrane showed better fouling resistance than the TFC one in the feed solution containing 200 ppm of sodium alginate as a foulant model.

  10. Trace organic solutes in closed-loop forward osmosis applications: influence of membrane fouling and modeling of solute build-up.

    Science.gov (United States)

    D'Haese, Arnout; Le-Clech, Pierre; Van Nevel, Sam; Verbeken, Kim; Cornelissen, Emile R; Khan, Stuart J; Verliefde, Arne R D

    2013-09-15

    In this study, trace organics transport in closed-loop forward osmosis (FO) systems was assessed. The FO systems considered, consisted of an FO unit and a nanofiltration (NF) or reverse osmosis (RO) unit, with the draw solution circulating between both units. The rejection of trace organics by FO, NF and RO was tested. It was found that the rejection rates of FO were generally comparable with NF and lower than RO rejection rates. To assess the influence of fouling in FO on trace organics rejection, FO membranes were fouled with sodium alginate, bovine serum albumin or by biofilm growth, after which trace organics rejection was tested. A negative influence of fouling on FO rejection was found which was limited in most cases, while it was significant for some compounds such as paracetamol and naproxen, indicating specific compound-foulant interactions. The transport mechanism of trace organics in FO was tested, in order to differentiate between diffusive and convective transport. The concentration of trace organics in the final product water and the build-up of trace organics in the draw solution were modeled assuming the draw solution was reconcentrated by NF/RO and taking into account different transport mechanisms for the FO membrane and different rejection rates by NF/RO. Modeling results showed that if the FO rejection rate is lower than the RO rejection rate (as is the case for most compounds tested), the added value of the FO-RO cycle compared to RO only at steady-state was small for diffusively and negative for convectively transported trace organics. Modeling also showed that trace organics accumulate in the draw solution. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Forward Osmosis Process

    KAUST Repository

    Duan, Jintang

    2013-12-05

    A process that can alleviate the internal concentration polarization and can enhance membrane performance of a forward osmosis system includes the steps of passing a fluid in a forward osmosis system from a feed solution with a first osmotic pressure, through a membrane into a draw solution comprising a draw solute with a second osmotic pressure, where the first osmotic pressure is lower than the second osmotic pressure, the membrane includes an active layer and a support layer, and the membrane is oriented such that the active layer of the membrane faces a draw side, and the support layer faces a feed side; and applying an external force to the fluid on the feed side of the membrane.

  12. Forward Osmosis Process

    KAUST Repository

    Duan, Jintang; Pinnau, Ingo; Litwiller, Eric

    2013-01-01

    A process that can alleviate the internal concentration polarization and can enhance membrane performance of a forward osmosis system includes the steps of passing a fluid in a forward osmosis system from a feed solution with a first osmotic pressure, through a membrane into a draw solution comprising a draw solute with a second osmotic pressure, where the first osmotic pressure is lower than the second osmotic pressure, the membrane includes an active layer and a support layer, and the membrane is oriented such that the active layer of the membrane faces a draw side, and the support layer faces a feed side; and applying an external force to the fluid on the feed side of the membrane.

  13. Hybrid membrane system for desalination and wastewater treatment: Integrating forward osmosis and low pressure reverse osmosis

    OpenAIRE

    Valladares Linares, R.

    2014-01-01

    Since more than 97% of the water in the world is seawater, desalination technologies have the potential to solve the fresh water crisis. The most used desalination technology nowadays is seawater reverse osmosis (SWRO), where a membrane is used as a physical barrier to separate the salts from the water, using high hydraulic pressure as the driving force. However, the use of high hydraulic pressure imposes a high cost on operation of these systems, in addition to the known persistent fouling p...

  14. Fouling of Seawater Reverse Osmosis (SWRO) Membrane: Chemical and Microbiological Characterization

    KAUST Repository

    Khan, Muhammad T.

    2013-01-01

    In spite of abundant water resources, world is suffering from the scarcity of usable water. Seawater Reverse Osmosis (SWRO) desalination technology using polymeric membranes has been recognized as a key solution to water scarcity problem. However

  15. Modification of PSf/SPSf Blended Porous Support for Improving the Reverse Osmosis Performance of Aromatic Polyamide Thin Film Composite Membranes

    Directory of Open Access Journals (Sweden)

    Li-Fen Liu

    2018-06-01

    Full Text Available In this study, modification of polysulfone (PSf/sulfonated polysulfone (SPSf blended porous ultrafiltration (UF support membranes was proposed to improve the reverse osmosis (RO performance of aromatic polyamide thin film composite (TFC membranes. The synergistic effects of solvent, polymer concentration, and SPSf doping content in the casting solution were investigated systematically on the properties of both porous supports and RO membranes. SEM and AFM were combined to characterize the physical properties of the membranes, including surface pore natures (porosity, mean pore radius, surface morphology, and section structure. A contact angle meter was used to analyze the membrane surface hydrophilicity. Permeate experiments were carried out to evaluate the separation performances of the membranes. The results showed that the PSf/SPSf blended porous support modified with 6 wt % SPSf in the presence of DMF and 14 wt % PSf had higher porosity, bigger pore diameter, and a rougher and more hydrophilic surface, which was more beneficial for fabrication of a polyamide TFC membrane with favorable reverse osmosis performance. This modified PSf/SPSf support endowed the RO membrane with a more hydrophilic surface, higher water flux (about 1.2 times, as well as a slight increase in salt rejection than the nascent PSf support. In a word, this work provides a new facile method to improve the separation performance of polyamide TFC RO membranes via the modification of conventional PSf porous support with SPSf.

  16. Novel technologies for reverse osmosis concentrate treatment: a review.

    Science.gov (United States)

    Joo, Sung Hee; Tansel, Berrin

    2015-03-01

    Global water shortages due to droughts and population growth have created increasing interest in water reuse and recycling and, concomitantly, development of effective water treatment processes. Pressured membrane processes, in particular reverse osmosis, have been adopted in water treatment industries and utilities despite the relatively high operational cost and energy consumption. However, emerging contaminants are present in reverse osmosis concentrate in higher concentrations than in the feed water, and have created challenges for treatment of the concentrate. Further, standards and guidelines for assessment and treatment of newly identified contaminants are currently lacking. Research is needed regarding the treatment and disposal of emerging contaminants of concern in reverse osmosis concentrate, in order to develop cost-effective methods for minimizing potential impacts on public health and the environment. This paper reviews treatment options for concentrate from membrane processes. Barriers to emerging treatment options are discussed and novel treatment processes are evaluated based on a literature review. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Using UCST ionic liquid as a draw solute in forward osmosis to treat high-salinity water

    KAUST Repository

    Zhong, Yujiang; Feng, Xiaoshuang; Chen, Wei; Wang, Xinbo; Huang, Kuo-Wei; Gnanou, Yves; Lai, Zhiping

    2015-01-01

    (trifluoromethylsulfonyl)imide ([Hbet][Tf2N]) was obtained by heating and maintaining the temperature above 56°C. This solution successfully drew water from high-salinity water up to 3.0 M through FO. When the IL solution cooled to room temperature, it spontaneously separated into a

  18. Effects of surface coating process conditions on the water permeation and salt rejection properties of composite polyamide reverse osmosis membranes

    KAUST Repository

    Louie, Jennifer Sarah; Pinnau, Ingo; Reinhard, Martin

    2011-01-01

    are impacted by the coating process steps, and investigates how such effects could contribute to lower water flux. On one hand, simply pre-soaking dry aromatic polyamide composite membranes in aliphatic alcohols results in a significant increase in water flux

  19. Biofouling of reverse-osmosis membranes during tertiary wastewater desalination: microbial community composition.

    Science.gov (United States)

    Al Ashhab, Ashraf; Herzberg, Moshe; Gillor, Osnat

    2014-03-01

    Reverse-osmosis (RO) desalination is frequently used for the production of high-quality water from tertiary treated wastewater (TTWW). However, the RO desalination process is often hampered by biofouling, including membrane conditioning, microbial adhesion, and biofilm growth. The vast majority of biofilm exploration concentrated on the role of bacteria in biofouling neglecting additional microbial contributors, i.e., fungi and archaea. To better understand the RO biofouling process, bacterial, archaeal and fungal diversity was characterized in a laboratory-scale RO desalination plant exploring the TTWW (RO feed), the RO membrane and the RO feed tube biofilms. We sequenced 77,400 fragments of the ribosome small subunit-encoding gene (16S and 18S rRNA) to identify the microbial community members in these matrices. Our results suggest that the bacterial, archaeal but not fungal community significantly differ from the RO membrane biofouling layer to the feedwater and tube biofilm (P < 0.01). Moreover, the RO membrane supported a more diverse community compared to the communities monitored in the feedwater and the biofilm attached to the RO feedwater tube. The tube biofilm was dominated by Actinobacteria (91.2 ± 4.6%), while the Proteobacteria phylum dominated the feedwater and RO membrane (at relative abundance of 92.3 ± 4.4% and 71.5 ± 8.3%, respectively), albeit comprising different members. The archaea communities were dominated by Crenarchaeota (53.0 ± 6.9%, 32.5 ± 7.2% and 69%, respectively) and Euryarchaeota (43.3 ± 6.3%, 23.2 ± 4.8% and 24%, respectively) in all three matrices, though the communities' composition differed. But the fungal communities composition was similar in all matrices, dominated by Ascomycota (97.6 ± 2.7%). Our results suggest that the RO membrane is a selective surface, supporting unique bacterial, and to a lesser extent archaeal communities, yet it does not select for a fungal community. Copyright © 2013

  20. Polishing Step Purification of High-Strength Wastewaters by Nanofiltration and Reverse Osmosis

    Directory of Open Access Journals (Sweden)

    Jinxiang Zhou

    2016-03-01

    Full Text Available This article reports findings on the use of nanofiltration (NF and reverse osmosis (RO for secondary treatment of high-strength rendering facility wastewaters following an ultrafiltration step. These wastewaters present significant challenges to classical treatment technologies. Constant-pressure, direct-flow membrane filtration experiments were done to screen for flux and effluent water permeate quality of ten commercial NF and RO membranes. All membranes tested were effective in reducing total dissolved salts (TDS and chemical oxygen demand (COD; however, only two membranes (Koch MPF-34 and Toray 70UB gave sufficiently stable flux values to warrant longer term cross-flow filtration studies. Cross-flow flux measurements, scanning electron microscopy (SEM, X-ray dispersive spectroscopy (EDS, and attenuated total reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR indicated that both membranes were eventually fouled by organic and inorganic foulants; however, the Toray 70UB RO membrane yielded a capacity of 1600 L/m2 prior to cleaning. A preliminary economic analysis compared the estimated costs of energy and consumables for a dual-stage UF/RO membrane process and dissolved air floatation (DAF and found membrane process costs could be less than about 40% of the current DAF process.

  1. High-performance multi-functional reverse osmosis membranes obtained by carbon nanotube·polyamide nanocomposite

    Science.gov (United States)

    Inukai, Shigeki; Cruz-Silva, Rodolfo; Ortiz-Medina, Josue; Morelos-Gomez, Aaron; Takeuchi, Kenji; Hayashi, Takuya; Tanioka, Akihiko; Araki, Takumi; Tejima, Syogo; Noguchi, Toru; Terrones, Mauricio; Endo, Morinobu

    2015-01-01

    Clean water obtained by desalinating sea water or by purifying wastewater, constitutes a major technological objective in the so-called water century. In this work, a high-performance reverse osmosis (RO) composite thin membrane using multi-walled carbon nanotubes (MWCNT) and aromatic polyamide (PA), was successfully prepared by interfacial polymerization. The effect of MWCNT on the chlorine resistance, antifouling and desalination performances of the nanocomposite membranes were studied. We found that a suitable amount of MWCNT in PA, 15.5 wt.%, not only improves the membrane performance in terms of flow and antifouling, but also inhibits the chlorine degradation on these membranes. Therefore, the present results clearly establish a solid foundation towards more efficient large-scale water desalination and other water treatment processes. PMID:26333385

  2. NOM and TEP fouling of a forward osmosis (FO) membrane: Foulant identification and cleaning

    KAUST Repository

    Valladares Linares, Rodrigo; Yangali-Quintanilla, Victor; Li, Zhenyu; Amy, Gary L.

    2012-01-01

    The study of forward osmosis (FO) membranes has increased due to the already demonstrated advantages compared to high-energy membrane processes such as reverse osmosis (RO). This research focuses on characterization of the natural organic matter (NOM) fraction causing fouling on the active layer (AL) of a FO membrane in a novel plate and frame module configuration, facing secondary wastewater effluent as a feed solution (FS) and seawater used as a draw solution (DS). In addition, transparent exopolymer particles (TEP) were observed on the support layer (SL) of the membrane in contact with the DS. The NOM fouling layer, after characterizing the water samples and membranes used, was found to be composed of biopolymers and protein-like substances, which adversely affect the flux of water through the FO membrane. However, NOM fouling showed high reversibility, up to 90% when air scouring for 15. min is used as a cleaning technique. The irreversible fouling in this work was found to be 8.2% after chemical cleaning. On the support layer of the membrane, TEP formed clusters clearly identifiable with an optical microscope and a TEP-specific dye. Chemical cleaning with 1% NaOCl for 10. min proved to be the most effective method to remove TEP. © 2012.

  3. NOM and TEP fouling of a forward osmosis (FO) membrane: Foulant identification and cleaning

    KAUST Repository

    Valladares Linares, Rodrigo

    2012-12-01

    The study of forward osmosis (FO) membranes has increased due to the already demonstrated advantages compared to high-energy membrane processes such as reverse osmosis (RO). This research focuses on characterization of the natural organic matter (NOM) fraction causing fouling on the active layer (AL) of a FO membrane in a novel plate and frame module configuration, facing secondary wastewater effluent as a feed solution (FS) and seawater used as a draw solution (DS). In addition, transparent exopolymer particles (TEP) were observed on the support layer (SL) of the membrane in contact with the DS. The NOM fouling layer, after characterizing the water samples and membranes used, was found to be composed of biopolymers and protein-like substances, which adversely affect the flux of water through the FO membrane. However, NOM fouling showed high reversibility, up to 90% when air scouring for 15. min is used as a cleaning technique. The irreversible fouling in this work was found to be 8.2% after chemical cleaning. On the support layer of the membrane, TEP formed clusters clearly identifiable with an optical microscope and a TEP-specific dye. Chemical cleaning with 1% NaOCl for 10. min proved to be the most effective method to remove TEP. © 2012.

  4. Assessment of Silt Density Index (SDI) as Fouling Propensity Parameter in Reverse Osmosis Desalination

    KAUST Repository

    Rachman, Rinaldi

    2011-07-01

    Reverse osmosis operations are facing persistent fouling phenomenon that has challenged the integrity of these processes. Prediction of fouling potential by measuring a fouling index toward feed water is essential to ensure robust operation. Moreover, employing a reliable fouling index with good reproducibility and precision is necessary. Silt density index (SDI) is considered insufficient in terms of reliability and empirical theory, among other limitations. Nevertheless due its simplicity, SDI measurement is utilized extensively in RO desalination systems. The aim of this research is to assess the reliability of SDI. Methods include the investigation of different SDI membranes and study of the nature of the SDI filtration. Results demonstrate the existence of the membrane properties\\' variation within manufacturers, which then causes a lack of accuracy in fouling risk estimation. The nature of particles during SDI filtration provides information that particle concentration and size play a significant role on SDI quantification with substantial representation given by particles with size close to membrane nominal pore size. Moreover, turbidity assisted SDI measurements along with determination of UF pretreated and clean water fouling potential, establishes the indication of non-fouling related phenomena involved on SDI measurement such as a natural organic matter adsorption and hydrodynamic condition that alters during filtration. Additionally, it was found that the latter affects the sensitivity of SDI by being represented by some portions of SDI value. Keywords: Reverse Osmosis, Fouling index, Particulate Fouling, Silt Density Index (SDI), and Assessment of SDI.

  5. Radiological map evolution in the treatment of 137Cs liquid wastes by a reverse osmosis plant

    International Nuclear Information System (INIS)

    Arnal, J.M.; Sancho, M.; Verdu, G.; Gozalvez, J.M.

    2002-01-01

    As a result of an accidental 1 37C s source melting in one of the furnaces of a stainless steel production company located in Spain, a part of the factory was radioactively contaminated. LAINSA (Logistica y Acondicionamientos Industriales S.A.) company took charge of the plant decontamination process, in which 40 m 3 , approximately, of 1 37C s contaminated water with a mean activity of 300 kBq/L were generated. After some preliminary tests in which the efficiency of reverse osmosis (RO) process in the treatment of 1 37C s contaminated effluent was proved, the radioactive liquid waste was treated by a reverse osmosis plant designed by the Chemical and Nuclear Engineering Department of the Polytechnic University of Valencia (UPV), and built by LAINSA company. Membrane techniques (microfiltration, ultrafiltration, nanofiltration and reverse osmosis) have become common in the treatment of radioactive effluents having substitute conventional treatments such as evaporation and ionic exchange. The main advantages of membrane processes used for concentrating radioactive wastes are moderate operating conditions, simple apparatus, high decontamination factors and low energy consumption. The treatment was carried out by the research team UPV-LAINSA, and it consisted in the application of reverse osmosis (RO) process with the main objective of reducing the waste volume to be disposed, obtaining a treated liquid with an activity less than the legal discharge limit for 1 37C s radioisotope (300 Bq/L). When working with radioactive effluents it is very important the radiological vigilance of working areas because it ensures that neither exposed personnel nor general public receive doses above established limits. Radiological vigilance consists in determining (continuously or periodically) radiation and contamination levels in working areas and even in those places where personnel can temporarily stand. The aim of this paper is to assess the evolution of radiation levels of the

  6. Boron Removal from Seawater by Thin-Film Composite Reverse Osmosis Membranes

    KAUST Repository

    Al Sunbul, Yasmeen

    2018-04-01

    Reverse Osmosis membranes have been successfully proven to remove almost 99% of chemicals dissolved in seawater. However, removal of certain trace elements, such as boron is challenging and relatively low for seawater reverse osmosis desalination plants compared to thermal desalination plants. Boron is naturally occurring and is present in seawater at an average concentration of 4.5-5 mg/L. While boron is a vital element, its toxicity has been proven on crops, animals and possibly humans. Additionally, boron should be removed to comply with the current guideline value of 0.5 mg/L, for drinking water, issued by the World Health Organization (WHO), which is barely attained by a single-pass process seawater reverse osmosis plant. Currently, multipass reverse osmosis membrane operations with pH modifications are the only valid method for boron removal. However, this is not economically efficient as it requires higher energy and chemicals consumptions. The objective of this study was to investigate boron removal by commercial TFC RO membranes in addition to custom-made KAUST-synthesized TFC membrane. Five membrane samples were examined: Toray, Sepro, Koch, and KAUST in-house synthesized membrane. Three different feed pH conditions were used: pH6, pH8, and pH10. Filtration experiments were conducted in two parts. In experiment 1, all five membranes were examined for boron rejection in a dead-end permeation system, whereas in experiment 2 the two membranes with the highest boron rejection from experiment 1 were tested in a cross-flow system. Permeate and feed samples were taken continuously and analyzed for boron concentration, rejection calculation. Membrane surfaces were characterized according to hydrophilicity, roughness and surface charge. The results showed for all the tested membranes that boron rejection increased as the feed pH increased. KAUST, defect-free TFC, showed the highest performance for boron rejection for all pH conditions, although, it shows the

  7. Osmosis and Diffusion Conceptual Assessment

    Science.gov (United States)

    Fisher, Kathleen M.; Williams, Kathy S.; Lineback, Jennifer Evarts

    2011-01-01

    Biology student mastery regarding the mechanisms of diffusion and osmosis is difficult to achieve. To monitor comprehension of these processes among students at a large public university, we developed and validated an 18-item Osmosis and Diffusion Conceptual Assessment (ODCA). This assessment includes two-tiered items, some adopted or modified…

  8. Disinfection Byproduct Formation in Reverse-Osmosis Concentrated and Lyophilized Natural Organic Matter from a Drinking Water Source

    Science.gov (United States)

    Drinking water treatment and disinfection byproduct (DBP) research can be complicated by natural organic matter (NOM) temporal variability. NOM preservation by lyophilization (freeze-drying) has been long practiced to address this issue; however, its applicability for drinking wa...

  9. Evaluation of Military Field-Water Quality. Volume 8. Performance of Mobile Water-Purification Unit (MWPU) and Pretreatment Components of the 600-GPH Reverse Osmosis Water Purification Unit (ROWPU), and Consideration of Reverse Osmosis (RO) Bypass, Potable-Water Disinfection, and Water-Quality Analysis Techniques

    Science.gov (United States)

    1990-05-01

    103 vi Volume 8 LIST OF TABLES I. Effect of coagulant dosage and type on the removal of Giardia muris cysts and coliform...that although some 34 Volume 8 Table 1. Effect of coagulant dosage and type on the removal of Giardia muris cysts and coliform bacteria by direct... Giardia muris cysts (5 to 13 mm) or cyst-sized particles with direct deep-bed filtration. With the sole exception of the study by Duncan, 48

  10. Evaluation of multivariate statistical analyses for monitoring and prediction of processes in an seawater reverse osmosis desalination plant

    International Nuclear Information System (INIS)

    Kolluri, Srinivas Sahan; Esfahani, Iman Janghorban; Garikiparthy, Prithvi Sai Nadh; Yoo, Chang Kyoo

    2015-01-01

    Our aim was to analyze, monitor, and predict the outcomes of processes in a full-scale seawater reverse osmosis (SWRO) desalination plant using multivariate statistical techniques. Multivariate analysis of variance (MANOVA) was used to investigate the performance and efficiencies of two SWRO processes, namely, pore controllable fiber filterreverse osmosis (PCF-SWRO) and sand filtration-ultra filtration-reverse osmosis (SF-UF-SWRO). Principal component analysis (PCA) was applied to monitor the two SWRO processes. PCA monitoring revealed that the SF-UF-SWRO process could be analyzed reliably with a low number of outliers and disturbances. Partial least squares (PLS) analysis was then conducted to predict which of the seven input parameters of feed flow rate, PCF/SF-UF filtrate flow rate, temperature of feed water, turbidity feed, pH, reverse osmosis (RO)flow rate, and pressure had a significant effect on the outcome variables of permeate flow rate and concentration. Root mean squared errors (RMSEs) of the PLS models for permeate flow rates were 31.5 and 28.6 for the PCF-SWRO process and SF-UF-SWRO process, respectively, while RMSEs of permeate concentrations were 350.44 and 289.4, respectively. These results indicate that the SF-UF-SWRO process can be modeled more accurately than the PCF-SWRO process, because the RMSE values of permeate flowrate and concentration obtained using a PLS regression model of the SF-UF-SWRO process were lower than those obtained for the PCF-SWRO process.

  11. Evaluation of multivariate statistical analyses for monitoring and prediction of processes in an seawater reverse osmosis desalination plant

    Energy Technology Data Exchange (ETDEWEB)

    Kolluri, Srinivas Sahan; Esfahani, Iman Janghorban; Garikiparthy, Prithvi Sai Nadh; Yoo, Chang Kyoo [Kyung Hee University, Yongin (Korea, Republic of)

    2015-08-15

    Our aim was to analyze, monitor, and predict the outcomes of processes in a full-scale seawater reverse osmosis (SWRO) desalination plant using multivariate statistical techniques. Multivariate analysis of variance (MANOVA) was used to investigate the performance and efficiencies of two SWRO processes, namely, pore controllable fiber filterreverse osmosis (PCF-SWRO) and sand filtration-ultra filtration-reverse osmosis (SF-UF-SWRO). Principal component analysis (PCA) was applied to monitor the two SWRO processes. PCA monitoring revealed that the SF-UF-SWRO process could be analyzed reliably with a low number of outliers and disturbances. Partial least squares (PLS) analysis was then conducted to predict which of the seven input parameters of feed flow rate, PCF/SF-UF filtrate flow rate, temperature of feed water, turbidity feed, pH, reverse osmosis (RO)flow rate, and pressure had a significant effect on the outcome variables of permeate flow rate and concentration. Root mean squared errors (RMSEs) of the PLS models for permeate flow rates were 31.5 and 28.6 for the PCF-SWRO process and SF-UF-SWRO process, respectively, while RMSEs of permeate concentrations were 350.44 and 289.4, respectively. These results indicate that the SF-UF-SWRO process can be modeled more accurately than the PCF-SWRO process, because the RMSE values of permeate flowrate and concentration obtained using a PLS regression model of the SF-UF-SWRO process were lower than those obtained for the PCF-SWRO process.

  12. Advantages and application of forward osmosis

    Science.gov (United States)

    This month's Processing column explores the use of forward osmosis to dewater and concentrate. Forward osmosis is performed with specially designed membranes and requires very little energy. Where thermal evaporation and reverse osmosis may damage or alter products, forward osmosis preserves the s...

  13. Comparative productivity of distillation and reverse osmosis desalination using energy from solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Tleimat, B.W.; Howe, E.D.

    1982-11-01

    This paper presents comparative analyses of two methods for producing desalted water using the heat collected by a solar pond - the first by distillation, and the second by reverse osmosis. The distillation scheme uses a multiple-effect distiller supplied with steam generated in a flash boiler using heat from a solar pond. Solar pond water passes through a heat exchanger in the water system ahead of the flash boiler. The second scheme uses a similar arrangement to generate hydrocarbon vapor which drives a Rankine cycle engine. This engine produces mechanical/ electrical power for the RO plant. The analyses use two pond water temperatures -82.2/sup 0/C (180/sup 0/F) and 71.1/sup 0/C (160/sup 0/F) -- which seem to cover the range expected from salt-gradient ponds. In each case, the pond water temperature drops by 5.56/sup 0/C (10/sup 0/F) while passing through the vapor generator system. Results of these analyses show that, based on the assumptions made, desalted water could be produced by distillation at productivity rates much greater than those estimated for the RO plant.

  14. Comparative productivity of distillation and reverse osmosis desalination using energy from solar ponds

    Energy Technology Data Exchange (ETDEWEB)

    Tleimat, B.W.; Howe, E.D.

    1982-11-01

    This paper presents comparative analyses of two methods for producing desalted water using the heat collected by a solar pond - the first by distillation, and the second by reverse osmosis. The distillation scheme uses a multiple-effect distiller supplied with steam generated in a flash boiler using heat from a solar pond. Solar pond water passes through a heat exchanger in the water system ahead of the flash boiler. The second scheme uses a similar arrangement to generate hydrocarbon vapor which drives a Rankine cycle engine. This engine produces mechanical/ electrical power for the RO plant. The analyses use two pond water temperatures 82.2/sup 0/C (180/sup 0/F) and 71.1/sup 0/C (160/sup 0/F) - which seem to cover the range expected from salt-gradient ponds. In each case, the pond water temperature drops by 5.56/sup 0/C (10/sup 0/F) while passing through the vapor generator system. Results of these analyses show that, based on the assumptions made, desalted water could be produced by distillation at productivity rates much greater than those estimated for the RO plant.

  15. Reverse osmosis membrane allows in situ regeneration

    International Nuclear Information System (INIS)

    Bonhomme, N.; Menjeaud, C.; Poyet, C.

    1989-01-01

    The use of mineral membranes on metallic supports has provided a novel solution to the problem of filtration by the reverse osmosis process. A new reverse osmosis membrane is described which is capable of resisting high operational temperatures (120 0 C), fluctuations in pH(3 to 12) and high pressure (100 bar), as well as significant chlorine concentrations. In addition, the membrane can be regenerated in-situ on the same porous metal support. Numerous membranes can thus be used over the multi-year life of the porous support. Moreover, accidental damage to the membrane is of no great consequence as the membrane itself can be easily replaced. The life of the installation can thus be extended and the overall cost of filtration reduced. The membrane's various applications include water and effluent treatment in the nuclear power industry. (author)

  16. Influence of ion size and charge on osmosis.

    Science.gov (United States)

    Cannon, James; Kim, Daejoong; Maruyama, Shigeo; Shiomi, Junichiro

    2012-04-12

    Osmosis is fundamental to many processes, such as in the function of biological cells and in industrial desalination to obtain clean drinking water. The choice of solute in industrial applications of osmosis is highly important in maximizing efficiency and minimizing costs. The macroscale process of osmosis originates from the nanoscale properties of the solvent, and therefore an understanding of the mechanisms of how these properties determine osmotic strength can be highly useful. For this reason, we have undertaken molecular dynamics simulations to systematically study the influence of ion size and charge on the strength of osmosis of water through carbon nanotube membranes. Our results show that strong osmosis occurs under optimum conditions of ion placement near the region of high water density near the membrane wall and of maintenance of a strong water hydration shell around the ions. The results in turn allow greater insight into the origin of the strong osmotic strength of real ions such as NaCl. Finally, in terms of practical simulation, we highlight the importance of avoiding size effects that can occur if the simulation cell is too small.

  17. Design considerations for wastewater treatment by reverse osmosis.

    Science.gov (United States)

    Bartels, C R; Wilf, M; Andes, K; Iong, J

    2005-01-01

    Reverse Osmosis is finding increasing use for the treatment of municipal and industrial wastewaters due to the growing demand for high quality water in large urban areas. The growing success of membranes in this application is related to improved process designs and improved membrane products. Key factors which have been determined to result in successful operation of large-scale plants will be discussed. Factors which play a key role in the use of RO membranes include ultra or microfiltration pretreatment, low fouling membranes, flux rate, recovery and control of fouling and scaling. In particular, high flux rates can be used when UF or MF pretreatment is used. These technologies remove most of the suspended particles that would normally cause heavy fouling of lead elements. Typically, fluxes in the range of 17-21 lmh lead to cleaning frequencies in the range of 3-4 months. By combining the use of membrane pretreatment and chloramination of the feed water through chlorine addition, two of the primary sources of RO membrane fouling can be controlled. The use of chloramine has become a proven means to control biofouling in a membrane for wastewater applications. The other significant problems for RO membranes result from organics fouling by dissolved organics and scaling due to saturation of marginally soluble salts. The former can be a significant problem for membranes, due to the strong attraction forces. To some extent, these can be mitigated by making the membrane surface more hydrophilic or changing the charge of the membrane surface. To minimize fouling, many plants are turning to low fouling membranes. Extensive studies have demonstrated that the membrane surface is hydrophilic, neutrally charged over a broad pH range, and more resistant to organic adsorption. Also, an analysis of the potential scaling issues will be reviewed. In particular, calcium phosphate has been found to be one of the key scalants that will limit RO system recovery rate. Calcium

  18. Integrating Microbial Electrochemical Technology with Forward Osmosis and Membrane Bioreactors: Low-Energy Wastewater Treatment, Energy Recovery and Water Reuse

    KAUST Repository

    Werner, Craig M.

    2014-01-01

    Wastewater treatment is energy intensive, with modern wastewater treatment processes consuming 0.6 kWh/m3 of water treated, half of which is required for aeration. Considering that wastewater contains approximately 2 kWh/m3 of energy and represents

  19. Investigation of pressure retarded osmosis power production

    Directory of Open Access Journals (Sweden)

    Taousanidis Nikolaos

    2017-01-01

    Full Text Available A major source of energy exists where there is mixing between aqueous solutions of different salinities. This energy source is particularly concentrated where fresh water rivers flow on to the ocean. The power, represented by the osmotic pressure difference between fresh water and salt water, may be called salinity gradient power. In this study the pressure retarded osmosis method for the extraction of salinity gradients’ energy is investigated, main problems and difficulties are pointed out and finally the whole subject is justified with experimental results.

  20. Drying brick masonry by electro-osmosis

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Rörig-Dalgaard, Inge

    2006-01-01

    When a fine grained, porous medium is applied an electric DC field, transport of matter occurs, and the transport mechanism in focus of the present study is electro-osmosis, which is transport of water. In laboratory it was shown possible to transport water inside a brick and brick/mortar system...... movement of water towards the cathode was seen. Thus the basis for utilizing the electro-osmotic effect for drying brick masonry is present, but proper electrodes still needs to be developed....

  1. Molecular cloning of Brevundimonas diminuta for efficacy assessment of reverse osmosis devices.

    Science.gov (United States)

    Donofrio, Robert; Saha, Ratul; Bestervelt, Lori; Bagley, Susan

    2012-06-01

    Brevundimonas diminuta is the test organism specified in the United States Environmental Protection Agency's (USEPA) reverse osmosis (RO) treatment device verification protocol. As non-selective growth medium is employed, enumeration of B. diminuta may be impaired due to interference by indigenous heterotrophic bacteria. Thus the microbial removal capability of the filtration system may be incorrectly assessed. As these treatment devices are used in emergency situations, the health of the public could be compromised. The objective of this study was to develop selective approaches for enumerating viable B. diminuta in test water. Two molecular approaches were investigated: expression of a kanamycin resistance gene and expression of a fluorescent protein gene. The USEPA protocol specifies a 0.3 μm cell size, so the expression of the selective markers were assessed following growth on media designed to induce this small cell diameter. The kan(R) strain was demonstrated to be equivalent to the wild type in cell dimension and survival following exposure to the test water. The kan(R) strain showed equivalent performance to the wild type in the RO protocol indicating that it is a viable alternative surrogate. By utilizing this strain, a more accurate validation of the RO system can be achieved.

  2. RoMo

    DEFF Research Database (Denmark)

    Pedersen, Esben Warming; Hornbæk, Kasper

    2011-01-01

    In TUIs, physical/digital conflicts can occur when the digital model does not match the model implied by the spatial lay- out of tangibles. We show how tangible tabletop interfaces (TTI) can be modified to allow robot movement of tangi- bles, thereby avoiding conflicts. We present RoMo, an open...... source Java library that allow existing TTI applications to perform robot movement, and demonstrate its functionality with three applications....

  3. Removing Fe, Zn and Mn from steel making plant wastewater using RO and NF membranes

    Directory of Open Access Journals (Sweden)

    Seyed Ahmad Mirbagheri

    2016-12-01

    Full Text Available Background and purpose: Excessive amount of heavy metals in industrial wastewater is a seriously crucial issue and requires efficient methods to be introduced and dealt with. Meanwhile, steel making plants as productive units in every country release large amounts of fluid into surface and underground sources. Typically, this wastewater contains heavy metals in minor amounts, while this amount could cause severe damages to the living organisms. Materials and methods: In this study, removing iron, manganese, zinc and total dissolved solid in a typical wastewater resulted from steel making plant was considered using reverse osmosis (RO and nanofiltration (NF membranes. At first, different pH values and operating pressures were applied to the wastewater. Then, these parameters were evaluated for a wastewater only containing iron to compare the interaction of other elements in iron removal. Results: The results indicated that RO and NF membranes could successfully treat industrial wastewater containing several heavy metals with high concentrations of Fe, Zn and Mn, especially at optimum pH and pressure. Moreover, the interaction of other heavy metals and components in the influent decreased the efficiency of RO but improved the NF efficiency to remove iron. To have a better image, a formula was proposed for each method to represent the influence of the parameters on removal rates. Finally, cost estimation for both procedures showed that RO was not economically-technically efficient in comparison with NF. Conclusion: NF showed an acceptable performance with high water flow which made it more suitable for industries. At the end, the relative cost analysis showed that even if the initial price of NF is high, the energy consumption and total cost of RO will be higher.

  4. Solar fired combined RO/MED desalination plant integrated with electrical power grid

    International Nuclear Information System (INIS)

    Alrobaei, H.

    2006-01-01

    Currently, there is a strong demand for efficient seawater desalination plants, which can meet the tougher environment regulation and energy saving requirements. From this standpoint the present work was undertaken to include proposed scheme (solar Fired Combined Reverse Osmosis (ROY Multi-Effect Distillation (MED) Seawater desalination Plant (SCDP) integrated with electrical power grid (EPG)) for repowering and modification of the conventional grid connected RO desalination plants. The model of SCDP during sunny periods may be applied to the following modes operation: *Full solar desalination (i.e. solar thermal and electrical power generation in solar plant is elivered to the desalination process and the surplus electricity is fed into EPG). *Hybrid solar desalination (I.e. a small share of the electrical power consumption for desalination process compensated by EPG). During cloudly periods and at night the SCDP operates as a conventional RO desalination plant. To establish the range, in which solar energy for seawater desalination would be competitive to fossil energy and investigates the potential effect of the proposed scheme on the repowering effectiveness, mathematical model has been developed. The repowered effectiveness, mathematical model has been developed.The repowered effectiveness in optaimizing model was characterized by the condition of attaining maximum fuel saving in the EPG. The study result shows the effectiveness of proposed scheme for modification and repowering the RO plant. For the case study. (SCDP with maual share of solar electrical power generation 67.4%) the economical effect amount 138.9 ton fuel/year for each MW design thermal energy of parabolic solar collectors array and the corresponding decrease in exhaust gases emission (Nitrogen oxides (NO x ) 0.55 ton/year.MW, carbon dioxides (CO2) 434.9 ton/year.MW). Moreover, implementation of combined RO/MED design for repowering and modification of conventional grid connected RO plant will

  5. Full-scale simulation of seawater reverse osmosis desalination processes for boron removal: Effect of membrane fouling.

    Science.gov (United States)

    Park, Pyung-Kyu; Lee, Sangho; Cho, Jae-Seok; Kim, Jae-Hong

    2012-08-01

    The objective of this study is to further develop previously reported mechanistic predictive model that simulates boron removal in full-scale seawater reverse osmosis (RO) desalination processes to take into account the effect of membrane fouling. Decrease of boron removal and reduction in water production rate by membrane fouling due to enhanced concentration polarization were simulated as a decrease in solute mass transfer coefficient in boundary layer on membrane surface. Various design and operating options under fouling condition were examined including single- versus double-pass configurations, different number of RO elements per vessel, use of RO membranes with enhanced boron rejection, and pH adjustment. These options were quantitatively compared by normalizing the performance of the system in terms of E(min), the minimum energy costs per product water. Simulation results suggested that most viable options to enhance boron rejection among those tested in this study include: i) minimizing fouling, ii) exchanging the existing SWRO elements to boron-specific ones, and iii) increasing pH in the second pass. The model developed in this study is expected to help design and optimization of the RO processes to achieve the target boron removal at target water recovery under realistic conditions where membrane fouling occurs during operation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Nitric oxide treatment for the control of reverse osmosis membrane biofouling.

    Science.gov (United States)

    Barnes, Robert J; Low, Jiun Hui; Bandi, Ratnaharika R; Tay, Martin; Chua, Felicia; Aung, Theingi; Fane, Anthony G; Kjelleberg, Staffan; Rice, Scott A

    2015-04-01

    Biofouling remains a key challenge for membrane-based water treatment systems. This study investigated the dispersal potential of the nitric oxide (NO) donor compound, PROLI NONOate, on single- and mixed-species biofilms formed by bacteria isolated from industrial membrane bioreactor and reverse osmosis (RO) membranes. The potential of PROLI NONOate to control RO membrane biofouling was also examined. Confocal microscopy revealed that PROLI NONOate exposure induced biofilm dispersal in all but two of the bacteria tested and successfully dispersed mixed-species biofilms. The addition of 40 μM PROLI NONOate at 24-h intervals to a laboratory-scale RO system led to a 92% reduction in the rate of biofouling (pressure rise over a given period) by a bacterial community cultured from an industrial RO membrane. Confocal microscopy and extracellular polymeric substances (EPS) extraction revealed that PROLI NONOate treatment led to a 48% reduction in polysaccharides, a 66% reduction in proteins, and a 29% reduction in microbial cells compared to the untreated control. A reduction in biofilm surface coverage (59% compared to 98%, treated compared to control) and average thickness (20 μm compared to 26 μm, treated compared to control) was also observed. The addition of PROLI NONOate led to a 22% increase in the time required for the RO module to reach its maximum transmembrane pressure (TMP), further indicating that NO treatment delayed fouling. Pyrosequencing analysis revealed that the NO treatment did not significantly alter the microbial community composition of the membrane biofilm. These results present strong evidence for the application of PROLI NONOate for prevention of RO biofouling. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Forward osmosis membrane fouling and cleaning for wastewater reuse

    Directory of Open Access Journals (Sweden)

    Youngbeom Yu

    2017-06-01

    Full Text Available Membrane fouling properties and different physical cleaning methods for forward osmosis (FO and reverse osmosis (RO laboratory-scale filtration systems were investigated. The membrane fouling, with respect to flux reduction, was lower in FO than in RO when testing an activated sludge effluent. Cross-flow velocity, air-scouring, osmotic backwashing and effect of a spacer were compared to determine the most effective cleaning method for FO. After a long period of fouling with activated sludge, the flux was fully recovered in a short period of osmotic backwashing compared with cleaning by changing cross-flow velocity and air-scouring. In this study, the osmotic backwashing was found to be the most efficient way to clean the FO membrane. The amount of RNA recovered from FO membranes was about twice that for RO membranes; biofouling could be more significant in FO than in RO. However, the membrane fouling in FO was lower than that in RO. The spacer increased the flux in FO with activated sludge liquor suspended solids of 2,500 mg/L, and there were effects of spacer on performance of FO–MBR membrane fouling. However, further studies are required to determine how the spacer geometry influences on the performance of the FO membrane.

  8. Enhancing forward osmosis water recovery from landfill leachate by desalinating brine and recovering ammonia in a microbial desalination cell.

    Science.gov (United States)

    Iskander, Syeed Md; Novak, John T; He, Zhen

    2018-05-01

    In this work, a microbial desalination cell (MDC) was employed to desalinate the FO treated leachate for reduction of both salinity and chemical oxygen demand (COD). The FO recovered 51.5% water from a raw leachate and the recovery increased to 83.5% from the concentrated leachate after desalination in the MDC fed with either acetate or another leachate as an electron source and at a different hydraulic retention time (HRT). Easily-degraded substrate like acetate and a long HRT resulted in a low conductivity desalinated effluent. Ammonia was also recovered in the MDC cathode with a recovery efficiency varying from 11 to 64%, affected by current generation and HRT. Significant COD reduction, as high as 65.4%, was observed in the desalination chamber and attributed to the decrease of both organic and inorganic compounds via diffusion and electricity-driven movement. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Nitrate-nitrogen removal with small-scale reverse osmosis ...

    African Journals Online (AJOL)

    The nitrate-nitrogen concentration in water supplied to clinics in Limpopo Province is too high to be fit for human consumption (35 to 75 mg/ℓ NO3-N). Therefore, small-scale technologies (reverse osmosis, ion-exchange and electrodialysis) were evaluated for nitrate-nitrogen removal to make the water potable (< 10 mg/ℓ ...

  10. Pressure retarded osmosis from hypersaline sources - A review

    DEFF Research Database (Denmark)

    Bajraktari, Niada; Hélix-Nielsen, Claus; Madsen, Henrik T.

    2017-01-01

    for commercialization. The scope of this paper is to review the existing knowledge on the use of hypersaline waters in the salinity gradient process, pressure retarded osmosis. Although only few papers have had the specific aim of investigating hypersaline waters, concentrated solutions have been used in many papers...

  11. Reverse osmosis treatment of wastes from the textile industry

    Energy Technology Data Exchange (ETDEWEB)

    Audran, J. [Electricite de France (EDF), 75 - Paris (France); Frizzarin, L.

    1995-09-01

    Reserve osmosis has been used in the textile industry for cleaning up effluent before sending it to the treatment plant. This process was preceded by a combination of flocculation and sedimentation. This system reduced water consumption since part of the water was reused, and also reduced the quantity of effluent to be dealt with by the treatment plant. (authors). 2 figs.

  12. Improvement in the makeup of Asco Nuclear Site with the addition of a R.O. plant to the makeup treatment

    International Nuclear Information System (INIS)

    Cascante, C.; Boronat, M.; Lloret, J.

    1988-01-01

    At present, the Asco nuclear site makes use of a complete water treatment support system that perform pretreatment (decarbonization, decantation, chlorination, filtration), reverse osmosis (regulation atmospheric tank, chemical conditioning of pretreated water, microfiltration, membrane chains, degasifier, pH correction), storage of osmotized water (atmospherical tank), demineralization (dechlorinizer, cationic exchanger, anionic exchanger, degasifier, strong anionic exchanger, catalytic reducer of oxygen, interchange of mixed layer), and storage of demineralized water (tank with atmospherical nitrogen). The installation of reverse osmosis equipment in the R.O. plant at the Asco nuclear site has its objective to reduce in a substantial way the total solids from the water coming from the Ebro river which is then submitted to a process of floculation, decarbonization, decantation and filtration, prior to total demineralization. The process is based on the property of semipermeable membranes in which a pressure is applied to water which contains dissolved solids, and only the dissolvent can pass through them, thus providing desalted water and a concentrate which contains the carried dissolved solids. (Nogami, K.)

  13. Using nanocomposite materials technology to understand and control reverse osmosis membrane compaction

    KAUST Repository

    Pendergast, Mary Theresa M.; Nygaard, Jodie M.; Ghosh, Asim K.; Hoek, Eric M.V.

    2010-01-01

    Composite reverse osmosis (RO) membranes were formed by interfacial polymerization of polyamide thin films over pure polysulfone and nanocomposite-polysulfone support membranes. Nanocomposite support membranes were formed from amorphous non-porous silica and crystalline microporous zeolite nanoparticles. For each hand-cast membrane, water flux and NaCl rejection were monitored over time at two different applied pressures. Nanocomposite-polysulfone supported RO membranes generally had higher initial permeability and experienced less flux decline due to compaction than pure polysulfone supported membranes. In addition, observed salt rejection tended to increase as flux declined from compaction. Crosssectional SEM images verified significant reduction in thickness of pure polysulfone supports, whereas nanocomposites better resisted compaction due to enhanced mechanical stability imparted by the nanoparticles. A conceptual model was proposed to explain the mechanistic relationship between support membrane compaction and observed changes in water flux and salt rejection. As the support membrane compacts, skin layer pore constriction increased the effective path length for diffusion through the composite membranes, which reduced both water and salt permeability identically. However, experimental salt permeability tended to decline to a greater extent than water permeability; hence, the observed changes in flux and rejection might also be related to structural changes in the polyamide thin film. © 2010 Elsevier B.V. All rights reserved.

  14. Using nanocomposite materials technology to understand and control reverse osmosis membrane compaction

    KAUST Repository

    Pendergast, Mary Theresa M.

    2010-10-01

    Composite reverse osmosis (RO) membranes were formed by interfacial polymerization of polyamide thin films over pure polysulfone and nanocomposite-polysulfone support membranes. Nanocomposite support membranes were formed from amorphous non-porous silica and crystalline microporous zeolite nanoparticles. For each hand-cast membrane, water flux and NaCl rejection were monitored over time at two different applied pressures. Nanocomposite-polysulfone supported RO membranes generally had higher initial permeability and experienced less flux decline due to compaction than pure polysulfone supported membranes. In addition, observed salt rejection tended to increase as flux declined from compaction. Crosssectional SEM images verified significant reduction in thickness of pure polysulfone supports, whereas nanocomposites better resisted compaction due to enhanced mechanical stability imparted by the nanoparticles. A conceptual model was proposed to explain the mechanistic relationship between support membrane compaction and observed changes in water flux and salt rejection. As the support membrane compacts, skin layer pore constriction increased the effective path length for diffusion through the composite membranes, which reduced both water and salt permeability identically. However, experimental salt permeability tended to decline to a greater extent than water permeability; hence, the observed changes in flux and rejection might also be related to structural changes in the polyamide thin film. © 2010 Elsevier B.V. All rights reserved.

  15. A novel TFC forward osmosis (FO) membrane supported by polyimide (PI) microporous nanofiber membrane

    Science.gov (United States)

    Chi, Xiang-Yu; Zhang, Ping-Yun; Guo, Xue-Jiao; Xu, Zhen-Liang

    2018-01-01

    A novel interfacial polymerization (IP) procedure on polyimide (PI) microporous nanofiber membrane support with mean pore size 1.27 μm was reported. Using m-phenylenediamine (MPD) as aqueous phase monomer, trimesoyl chloride (TMC) as organic phase monomer, ethanol as aqueous phase co-solvent, thin-film composite (TFC) forward osmosis (FO) membrane was fabricated by two IP procedures. The first IP procedure with the unconventional order (ie, the membrane was immersed in the TMC organic phase first, then in the co-solvent ethanol-water MPD aqueous phase) was used to diminish the pore size of PI microporous nanofiber membrane support for the formation of the polyamide layer. The secondary IP procedure was employed to form the relatively dense polyamide layer with conventional order (ie, the membrane was immersed in the co-solvent ethanol-water MPD aqueous phase first, then in the TMC organic phase). The experimental results showed that higher ethanol concentration led to the relatively higher pure water permeability in RO process and osmotic water flux in FO process, whereas NaCl rejection in RO process decreased and reverse salt flux increased. The specific salt flux (Js/Jv) of TFC FO PI nanofiber membrane (PIN-2-4) could be as low as 0.095 g/L in FO mode. These results could be attributed to influence of the addition of ethanol into aqueous phase on the surface morphology, hydrophilicity and polyamide layer structure.

  16. Environmental and economic assessment of hybrid FO-RO/NF system with selected inorganic draw solutes for the treatment of mine impaired water

    KAUST Repository

    Kim, Jung Eun; Phuntsho, Sherub; Chekli, Laura; Choi, Joon Yong; Shon, Ho Kyong

    2018-01-01

    draw solution (DS) by conducting environmental and economic life cycle assessment (LCA). Baseline environmental LCA showed that the dominant components to energy use and global warming are the DS recovery processes (i.e. RO or NF processes) and FO

  17. Biofouling of reverse-osmosis membranes under different shear rates during tertiary wastewater desalination: microbial community composition.

    Science.gov (United States)

    Al Ashhab, Ashraf; Gillor, Osnat; Herzberg, Moshe

    2014-12-15

    We investigated the influence of feed-water shear rate during reverse-osmosis (RO) desalination on biofouling with respect to microbial community composition developed on the membrane surface. The RO membrane biofilm's microbial community profile was elucidated during desalination of tertiary wastewater effluent in a flat-sheet lab-scale system operated under high (555.6 s(-1)), medium (370.4 s(-1)), or low (185.2 s(-1)) shear rates, corresponding to average velocities of 27.8, 18.5, and 9.3 cm s(-1), respectively. Bacterial diversity was highest when medium shear was applied (Shannon-Weaver diversity index H' = 4.30 ± 0.04) compared to RO-membrane biofilm developed under lower and higher shear rates (H' = 3.80 ± 0.26 and H' = 3.42 ± 0.38, respectively). At the medium shear rate, RO-membrane biofilms were dominated by Betaproteobacteria, whereas under lower and higher shear rates, the biofilms were dominated by Alpha- and Gamma- Proteobacteria, and the latter biofilms also contained Deltaproteobacteria. Bacterial abundance on the RO membrane was higher at low and medium shear rates compared to the high shear rate: 8.97 × 10(8) ± 1.03 × 10(3), 4.70 × 10(8) ± 1.70 × 10(3) and 5.72 × 10(6) ± 2.09 × 10(3) copy number per cm(2), respectively. Interestingly, at the high shear rate, the RO-membrane biofilm's bacterial community consisted mainly of populations known to excrete high amounts of extracellular polymeric substances. Our results suggest that the RO-membrane biofilm's community composition, structure and abundance differ in accordance with applied shear rate. These results shed new light on the biofouling phenomenon and are important for further development of antibiofouling strategies for RO membranes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Study of the Effect of Nanoparticles and Surface Morphology on Reverse Osmosis and Nanofiltration Membrane Productivity

    Directory of Open Access Journals (Sweden)

    Steven J. Duranceau

    2013-08-01

    Full Text Available To evaluate the significance of reverse osmosis (RO and nanofiltration (NF surface morphology on membrane performance, productivity experiments were conducted using flat-sheet membranes and three different nanoparticles, which included SiO2, TiO2 and CeO2. In this study, the productivity rate was markedly influenced by membrane surface morphology. Atomic force microscopy (AFM analysis of membrane surfaces revealed that the higher productivity decline rates associated with polyamide RO membranes as compared to that of a cellulose acetate NF membrane was due to the inherent ridge-and-valley morphology of the active layer. The unique polyamide active layer morphology was directly related to the surface roughness, and was found to contribute to particle accumulation in the valleys causing a higher flux decline than in smoother membranes. Extended RO productivity experiments using laboratory grade water and diluted pretreated seawater were conducted to compare the effect that different nanoparticles had on membrane active layers. Membrane flux decline was not affected by particle type when the feed water was laboratory grade water. On the other hand, membrane productivity was affected by particle type when pretreated diluted seawater served as feed water. It was found that CeO2 addition resulted in the least observable flux decline, followed by SiO2 and TiO2. A productivity simulation was conducted by fitting the monitored flux data into a cake growth rate model, where the model was modified using a finite difference method to incorporate surface thickness variation into the analysis. The ratio of cake growth term (k1 and particle back diffusion term (k2 was compared in between different RO and NF membranes. Results indicated that k2 was less significant for surfaces that exhibited a higher roughness. It was concluded that the valley areas of thin-film membrane surfaces have the ability to capture particles, limiting particle back diffusion.

  19. Biomimetic Membranes for Water Purification and Wastewater Treatment

    DEFF Research Database (Denmark)

    Tang, Chuyang Y.; Wang, Zhining; Hélix-Nielsen, Claus

    2016-01-01

    Reverse osmosis (RO)-based desalination and wastewater reclamation are gaining increasing popularity driven by water shortages and population growth. Advances in membrane technology in the past few decades have resulted in great savings in energy consumption of RO processes. Further reduction...... in energy consumption calls for novel membranes with significantly enhanced water permeability compared to the current state of the art thin-film composite polyamides. An attractive option is to learn from nature's high efficiently water filtration systems that involve a group of specialised water transport...

  20. Energy from salt and sweet water by means of osmosis. A visualization at the Afsluitdijk, Netherlands; Energie uit zout en zoet water met osmose. Een visualisatie bij de Afsluitdijk

    Energy Technology Data Exchange (ETDEWEB)

    Molenbroek, E.C. [Ecofys Netherlands, Utrecht (Netherlands)

    2007-10-17

    Osmotic energy is a promising source of renewable energy: quiet, clean and continuously available. The technical potential for Europe is estimated to be 200 TWh (over the whole world 1600 TWh), of which 16 TWh in the Netherlands and 1.6 TWh (1.6x10{sup 12} Wh) at the Afsluitdijk (32 km long dike in the Netherlands). The electricity production at the Afsluitdijk would be sufficient to supply electricity to 500,000 households. Osmotic energy power plants will be built where fresh water enters into the sea. In the Netherlands, Rijkswaterstaat manages dikes and other infrastructural works along the coast. In addition to this main task Rijkswaterstaat (RWS) has an active policy to minimise the use of energy of the infrastructural works in its care and to use sustainable energy as much as possible. This is the reason why Rijkswaterstaat wants to gain more in-depth knowledge of the properties and future possibilities of osmotic energy. For this purpose Ecofys has described the technology, the state of the art and the costs of the two existing types of osmotic energy generation and has made a visualisation of a future 10 MW power station at the Afsluitdijk. Attention is paid to the PRO-route (Pressure Retarded Osmosis) and the RED-option (Reverse ElectroDialysis) [Dutch] Osmotische energie is een veelbelovende duurzame energiebron: stil, schoon en continu beschikbaar. Het potentieel voor Europa wordt geschat op 200 TWh (over de hele wereld 1600 TWh), waarvan 16 TWh in Nederland en 1.6 TWh (1.6x10{sup 12} Wh) aan de Afsluitdijk. De energieproductie aan de Afsluitdijk zou goed zijn voor de elektriciteitsbehoefte van 500.000 huishoudens. Osmotische energiecentrales zullen komen te staan waar zoet water in zee stroomt. In Nederland beheert Rijkswaterstaat de dijken en andere infrastructurele werken langs de kust. Naast deze hoofdtaak heeft Rijkswaterstaat (RWS) een actief beleid om het energieverbruik van de infrastructurele werken onder haar beheer te minimaliseren en

  1. A novel reverse osmosis membrane by ferrous sulfate assisted controlled oxidation of polyamide layer

    Science.gov (United States)

    Raval, Hiren D.; Raviya, Mayur R.; Gauswami, Maulik V.

    2017-11-01

    With growing desalination capacity, it is very important to evaluate the performance of thin film composite reverse osmosis (TFC RO) membrane in terms of energy consumption for desalination. There is a trade-off between salt rejection and water-flux of TFC RO membrane. This article presents a novel approach of analyzing the effect of mixture of an oxidizing agent sodium hypochlorite and a reducing agent ferrous sulfate on virgin TFC RO membrane. Experiments were carried out by varying the concentrations of both sodium hypochlorite and ferrous sulfate. The negative charge was induced on the membrane due to the treatment of combination of sodium hypochlorite and ferrous sulfate, thereby resulting in higher rejection of negative ions due to repulsive force. Membrane treated with 1000 mg l-1 sodium hypochlorite and 2000 mg l-1 ferrous sulfate showed the best salt rejection i.e. 96.23%. The characterization was carried out to understand the charge on the membrane surface by Zeta potential, morphology of membrane surface by scanning electron microscope (SEM), surface roughness features by atomic force microscope (AFM) and chemical structural changes by nuclear magnetic resonance (NMR) analysis.

  2. Osmosis, osmometry, and osmoregulation

    Science.gov (United States)

    Lord, R

    1999-01-01

    The maintenance of adequate body fluid volume and the correct distribution of this fluid between the body compartments is a critical part of homeostasis. The process of osmosis plays an important role in movement of fluid within the body and the use of osmometry is an important part of the management of many patients. In addition to the application of osmometry to the measurement of body fluids, most commonly plasma and urine, osmotic action plays a part in some therapeutic actions of drugs and its strength needs to be quantified in fluids administered to patients. Unfortunately confusion often exists in the various terms that are used in the field of osmometry. This review aims to explain the different terms used, the laboratory methodology involved in osmometry, and the clinical application and interpretation of the results obtained.


Keywords: homeostasis; osmolality; osmolarity; colligative properties PMID:10448464

  3. Desalination of brackish and sea water

    International Nuclear Information System (INIS)

    Shukla, Dilip R.

    2005-01-01

    In Pali, Rajasthan, a population of 4 lacs gets about 6 million liters of water. Only 34 out of 116 municipalities in AP get regular water. Desalination found acceptance because of the decreasing water table leading to high salinity and making conventional treatment methods irrelevant. While choosing amongst the competitive desalination techniques that are available today for conversion of large quantities of saline water, Reverse Osmosis (RO) and distillation techniques stand out. RO rules the brackish water market where feed salinity is over 700 mg/L. Waste heat is nowadays a non-entity in power plants due to the developments of waste heat recovery systems in power plant technology. Most of the large plants tend to choose thermal desalination. Improved RO economics have in turn increased the attractiveness and use of seawater reverse osmosis (SWRO) technology for many large drinking water projects through out the world. Energy cost is the single largest factor in the cost of Sea Water System (usually 20 to 30% of total cost of water). Nuclear Power Corporation, Kudankulam proposed to build a SW desalination system based on RO technology to meet the water requirement of the Anu Vijay Nagar township and Nuclear Power Station. Energy recovery turbine helps reduce the overall system energy requirement. (author)

  4. An analysis of the effects of osmotic backwashing on the seawater reverse osmosis process.

    Science.gov (United States)

    Park, JunYoung; Jeong, WooWon; Nam, JongWoo; Kim, JaeHun; Kim, JiHoon; Chon, Kangmin; Lee, Euijong; Kim, HyungSoo; Jang, Am

    2014-01-01

    Fouling control is an important consideration in the design and operation of membrane-based water treatment processes. It has been generally known that chemical cleaning is still the most common method to remove foultants and maintain the performance of reverse osmosis (RO) desalination. Regardless of the chemical membrane cleaning methods applied effectively, however, frequent chemical cleaning can shorten the membrane life. In addition, it also increases operating and maintenance costs due to the waste chemical disposal. As an alternative, osmotic backwashing can be applied to RO membranes by diluting the concentration polarization (CP) layer. In this study, the effects of osmotic backwashing were analysed under different total dissolved salts (TDSs) and backwashing conditions, and the parameters of the osmotic backwashing were evaluated. The results of the analysis based on the properties of the organic matters found in raw water showed that the cleaning efficiency in respect to the fouling by hydrophilic organic matters was the greatest. Osmotic backwashing was carried out by changing the TDS of the permeate. As a result, the backwashing volume decreased with time due to the CP of the permeate and the backwashing volume. The difference in the osmotic pressure between the raw water and the permeate (Delta pi) also decreased as time passed. It was confirmed that when the temperature of the effluent was high, both the cleaning efficiency and the backwashing volume, which inpours at the same time, increased. When the circulation flow of the effluent was high, both the cleaning efficiency and the backwashing volume increased.

  5. Synthesis of magnetic nanoparticles as a draw solute in forward osmosis membrane process for the treatment of radioactive liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Heeman; Lee, Kune Woo; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    These wastes contain about 0.3 ∼ 0.8 wt% of boric acid. It is known that reverse osmosis (RO) membrane can eliminate boron at high pH and boron of 40 ∼ 90% can be removed by RO membrane in pH condition. RO uses hydraulic pressure to oppose, and exceed, the osmotic pressure of an aqueous feed solution containing boric acid. As an emerging technology forward osmosis (FO) has attracted growing interest in wastewater treatment and desalination because FO operates at low or no hydraulic pressures. FO is a membrane process in which water flows across a semi-permeable membrane from a feed solution of lower osmotic pressure to a draw solution of higher osmotic pressure. However, the challenges of FO still lie in the fabrication of eligible FO membranes and the readily separable draw solutes of high osmotic pressures. Superparamagnetic Fe{sub 3}O{sub 4} nanoparticles can be separated from water by an external magnet field easily. If Fe{sub 3}O{sub 4} nanoparticles are coated with highly soluble organic substances, thus they can be used as a draw solute by concurrently generating high osmotic pressure and easy separation. The carboxylated polyglycerol coated Fe{sub 3}O{sub 4} nanoparticles have been successfully synthesized. The nanoparticles were about 50 nm in diameter and showed the good colloidal stability in aqueous solution. The osmolality and osmotic pressure were enough high to be used as a draw solute in FO. For the future work, we will investigate the performance of our magnetic draw solute in FO to remove boron in the simulated liquid waste.

  6. Synthesis of magnetic nanoparticles as a draw solute in forward osmosis membrane process for the treatment of radioactive liquid waste

    International Nuclear Information System (INIS)

    Yang, Heeman; Lee, Kune Woo; Moon, Jei Kwon

    2013-01-01

    These wastes contain about 0.3 ∼ 0.8 wt% of boric acid. It is known that reverse osmosis (RO) membrane can eliminate boron at high pH and boron of 40 ∼ 90% can be removed by RO membrane in pH condition. RO uses hydraulic pressure to oppose, and exceed, the osmotic pressure of an aqueous feed solution containing boric acid. As an emerging technology forward osmosis (FO) has attracted growing interest in wastewater treatment and desalination because FO operates at low or no hydraulic pressures. FO is a membrane process in which water flows across a semi-permeable membrane from a feed solution of lower osmotic pressure to a draw solution of higher osmotic pressure. However, the challenges of FO still lie in the fabrication of eligible FO membranes and the readily separable draw solutes of high osmotic pressures. Superparamagnetic Fe 3 O 4 nanoparticles can be separated from water by an external magnet field easily. If Fe 3 O 4 nanoparticles are coated with highly soluble organic substances, thus they can be used as a draw solute by concurrently generating high osmotic pressure and easy separation. The carboxylated polyglycerol coated Fe 3 O 4 nanoparticles have been successfully synthesized. The nanoparticles were about 50 nm in diameter and showed the good colloidal stability in aqueous solution. The osmolality and osmotic pressure were enough high to be used as a draw solute in FO. For the future work, we will investigate the performance of our magnetic draw solute in FO to remove boron in the simulated liquid waste

  7. Future Energy Benchmark for Desalination: Is it Better to have a Power (Electricity) Plant With RO or MED/MSF?

    KAUST Repository

    Shahzad, Muhammad Wakil; Ng, Kim Choon; Thu, Kyaw

    2016-01-01

    Power and desalination cogeneration plants are common in many water scared courtiers. Designers and planners for cogeneration face tough challenges in deciding the options:- Is it better to operate a power plant (PP) with the reverse osmosis (i.e., PP+RO) or the thermally-driven multi-effect distillation/multi-stage flashed ( PP+MED/MSF) methods. From literature, the RO methods are known to be energy efficient whilst the MED/MSF are known to have excellent thermodynamic synergies as only low pressure and temperature steam are used. Not with-standing the challenges of severe feed seawater of the Gulf, such as the frequent harmful algae blooms (HABs) and high silt contents, this presentation presents a quantitative analyses using the exergy and energetic approaches in evaluating the performances of a real cogeneration plant that was recently proposed in the eastern part of Saudi Arabia. We demonstrate that the process choice of PP+RO versus PP+MED depends on the inherent efficiencies of individual process method which is closely related to innovative process design. In this connection, a method of primary fuel cost apportionment for a co-generation plant with a MED desalination is presented. We show that an energy approach, that captures the quality of expanding steam, is a better method over the conventional work output (energetic) and the energy method seems to be over-penalizing a thermally-driven MED by as much as 22% in the operating cost of water.

  8. Future Energy Benchmark for Desalination: is it Better to have a Power (electricity) Plant with ro or Med/msf?

    Science.gov (United States)

    Shahzad, Muhammad Wakil; Ng, Kim Choon; Thu, Kyaw

    2016-06-01

    Power and desalination cogeneration plants are common in many water scared courtiers. Designers and planners for cogeneration face tough challenges in deciding the options:- Is it better to operate a power plant (PP) with the reverse osmosis (i.e., PP+RO) or the thermally-driven multi-effect distillation/multi-stage flashed (PP+MED/MSF) methods. From literature, the RO methods are known to be energy efficient whilst the MED/MSF are known to have excellent thermodynamic synergies as only low pressure and temperature steam are used. Not with-standing the challenges of severe feed seawater of the Gulf, such as the frequent harmful algae blooms (HABs) and high silt contents, this presentation presents a quantitative analyses using the exergy and energetic approaches in evaluating the performances of a real cogeneration plant that was recently proposed in the eastern part of Saudi Arabia. We demonstrate that the process choice of PP+RO versus PP+MED depends on the inherent efficiencies of individual process method which is closely related to innovative process design. In this connection, a method of primary fuel cost apportionment for a co-generation plant with a MED desalination is presented. We show that an energy approach, that captures the quality of expanding steam, is a better method over the conventional work output (energetic) and the energy method seems to be over-penalizing a thermally-driven MED by as much as 22% in the operating cost of water.

  9. Future Energy Benchmark for Desalination: Is it Better to have a Power (Electricity) Plant With RO or MED/MSF?

    KAUST Repository

    Shahzad, Muhammad Wakil

    2016-06-23

    Power and desalination cogeneration plants are common in many water scared courtiers. Designers and planners for cogeneration face tough challenges in deciding the options:- Is it better to operate a power plant (PP) with the reverse osmosis (i.e., PP+RO) or the thermally-driven multi-effect distillation/multi-stage flashed ( PP+MED/MSF) methods. From literature, the RO methods are known to be energy efficient whilst the MED/MSF are known to have excellent thermodynamic synergies as only low pressure and temperature steam are used. Not with-standing the challenges of severe feed seawater of the Gulf, such as the frequent harmful algae blooms (HABs) and high silt contents, this presentation presents a quantitative analyses using the exergy and energetic approaches in evaluating the performances of a real cogeneration plant that was recently proposed in the eastern part of Saudi Arabia. We demonstrate that the process choice of PP+RO versus PP+MED depends on the inherent efficiencies of individual process method which is closely related to innovative process design. In this connection, a method of primary fuel cost apportionment for a co-generation plant with a MED desalination is presented. We show that an energy approach, that captures the quality of expanding steam, is a better method over the conventional work output (energetic) and the energy method seems to be over-penalizing a thermally-driven MED by as much as 22% in the operating cost of water.

  10. 3D visualization of the internal nanostructure of polyamide thin films in RO membranes

    KAUST Repository

    Pacheco Oreamuno, Federico

    2015-11-02

    The front and back surfaces of fully aromatic polyamide thin films isolated from reverse osmosis (RO) membranes were characterized by TEM, SEM and AFM. The front surfaces were relatively rough showing polyamide protuberances of different sizes and shapes; the back surfaces were all consistently smoother with very similar granular textures formed by polyamide nodules of 20–50 nm. Occasional pore openings of approximately the same size as the nodules were observed on the back surfaces. Because traditional microscopic imaging techniques provide limited information about the internal morphology of the thin films, TEM tomography was used to create detailed 3D visualizations that allowed the examination of any section of the thin film volume. These tomograms confirmed the existence of numerous voids within the thin films and revealed structural characteristics that support the water permeance difference between brackish water (BWRO) and seawater (SWRO) RO membranes. Consistent with a higher water permeance, the thin film of the BWRO membrane ESPA3 contained relatively more voids and thinner sections of polyamide than the SWRO membrane SWC3. According to the tomograms, most voids originate near the back surface and many extend all the way to the front surface shaping the polyamide protuberances. Although it is possible for the internal voids to be connected to the outside through the pore openings on the back surface, it was verified that some of these voids comprise nanobubbles that are completely encapsulated by polyamide. TEM tomography is a powerful technique for investigating the internal nanostructure of polyamide thin films. A comprehensive knowledge of the nanostructural distribution of voids and polyamide sections within the thin film may lead to a better understanding of mass transport and rejection mechanisms in RO membranes.

  11. 3D visualization of the internal nanostructure of polyamide thin films in RO membranes

    KAUST Repository

    Pacheco Oreamuno, Federico; Sougrat, Rachid; Reinhard, Martin; Leckie, James O.; Pinnau, Ingo

    2015-01-01

    The front and back surfaces of fully aromatic polyamide thin films isolated from reverse osmosis (RO) membranes were characterized by TEM, SEM and AFM. The front surfaces were relatively rough showing polyamide protuberances of different sizes and shapes; the back surfaces were all consistently smoother with very similar granular textures formed by polyamide nodules of 20–50 nm. Occasional pore openings of approximately the same size as the nodules were observed on the back surfaces. Because traditional microscopic imaging techniques provide limited information about the internal morphology of the thin films, TEM tomography was used to create detailed 3D visualizations that allowed the examination of any section of the thin film volume. These tomograms confirmed the existence of numerous voids within the thin films and revealed structural characteristics that support the water permeance difference between brackish water (BWRO) and seawater (SWRO) RO membranes. Consistent with a higher water permeance, the thin film of the BWRO membrane ESPA3 contained relatively more voids and thinner sections of polyamide than the SWRO membrane SWC3. According to the tomograms, most voids originate near the back surface and many extend all the way to the front surface shaping the polyamide protuberances. Although it is possible for the internal voids to be connected to the outside through the pore openings on the back surface, it was verified that some of these voids comprise nanobubbles that are completely encapsulated by polyamide. TEM tomography is a powerful technique for investigating the internal nanostructure of polyamide thin films. A comprehensive knowledge of the nanostructural distribution of voids and polyamide sections within the thin film may lead to a better understanding of mass transport and rejection mechanisms in RO membranes.

  12. A floating desalination/co-generation system using the KLT-40 reactor and Canadian RO desalination technology

    International Nuclear Information System (INIS)

    Humphries, J.R.; Davies, K.

    2000-01-01

    As the global consumption of water increases with growing populations and rising levels of industrialization, major new sources of potable water production must be developed. To address this issue efficiently and economically, a new approach has been developed in Canada for the integration of reverse osmosis (RO) desalination systems with nuclear reactors as an energy source. The resulting nuclear desalination/cogeneration plant makes use of waste heat from the electrical generation process to preheat the RO feedwater, advanced feedwater pre-treatment and sophisticated system design integration and optimization techniques. These innovations have led to improved water production efficiency, lower water production costs and reduced environmental impact. The Russian Federation is developing the KLT-40 reactor for application as a Floating Power Unit (FPU). The reactor is ideally suited for such purposes, having bad many years of successful operation as a marine propulsion reactor aboard floating nuclear powered icebreakers and other nuclear propelled vessels. Under the terms of a cooperation agreement with the Russian Federation Ministry of Atomic Energy, CANDESAL Enterprises Ltd has evaluated the FPU, containing two KLT-40 reactors, as a source of electrical energy and waste heat for RO desalination. A design concept for a floating nuclear desalination complex consisting of the FPU and a barge mounted RO desalination unit has been analyzed to establish preliminary performance characteristics for the complex. The FPU, operating as a barge mounted electrical generating station, provides electricity to the desalination barge. In addition, the condenser cooling water from the FPU is used as a source of preheated feedwater for the RO system on the desalination barge. The waste heat produced by the electrical generating process is sufficient to provide RO feedwater at a temperature of about 10 deg. C above ambient seawater temperature. Preliminary design studies have

  13. Use of biomimetic forward osmosis membrane for trace organics removal

    DEFF Research Database (Denmark)

    Madsen, Henrik T.; Bajraktari, Niada; Helix Nielsen, Claus

    2015-01-01

    The use of forward osmosis for the removal of trace organics from water has recently attracted considerable attention as an alternative to traditional pressure driven membrane filtration. However, the existing forward osmosis membranes have been found to be ineffective at rejecting small neutral...... organic pollutants, which limits the applicability of the forward osmosis process. In this study a newly developed biomimetic membrane was tested for the removal of three selected trace organics that can be considered as a bench marking test for a membrane[U+05F3]s ability to reject small neutral organic....... This difference is caused by differences in the transport mechanisms. For the cellulose acetate membrane rejection is controlled by steric hindrance, which results in a size dependent rejection of the trace organics, whereas rejection by the aquaporin membrane is controlled by diffusion of the trace organics...

  14. Separation of mixtures of organic substance using reverse osmosis membranes

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Shoji; Nakao, Shin' ichi; Tanimura, Shinobu

    1987-12-25

    With the arrival of energy crisis, attention has been concentrated on the production of alcohol by means of biomass conversion. Energy-saving concentration method was searched to replace a distillation method as a method of concentrating dilute alcohols, for which a reverse osmosis method was proposed; experimental results have been reported accordingly. One result is that the osmotic pressure method has a limitation of difficulty to exceed more than 15% concentration. For this, the reverse osmosis was reviewed and it was found that wider concentration range should be examined for the area where the reverse osmosis was not experimented. Fils employed were a polyamide film of Nitto Denko Co. and an acrylonitrile film of sumitomo Chemical Co.. The result revealed that alcohol could be concentrated up to rather high concentration in alcohol-water system; even in a non-aqueous system, separation with high selective permeability was possible by the proper selection of film materials. (4 figs, 2 refs)

  15. Global (50°S–50°N) distribution of water vapor observed by COSMIC GPS RO: Comparison with GPS radiosonde, NCEP, ERA-Interim, and JRA-25 reanalysis data sets

    CSIR Research Space (South Africa)

    Kishore, P

    2011-08-01

    Full Text Available In this study, global (50°S–50°N) distribution of water vapor is investigated using COSMIC GPS RO measurements. Detailed comparisons have been made between COSMIC and high resolution GPS radiosonde measurements across 13 tropical stations and model...

  16. High pressure membrane foulants of seawater, brackish water and river water: Origin assessed by sugar and bacteriohopanepolyol signatures

    KAUST Repository

    Mondamert, Leslie

    2011-01-01

    The present work aimed to study the origin of foulant material recovered on membranes used in water treatment. Firstly, sugar signatures were assessed from the monosaccharide composition. As results were not conclusive, a statistical approach using discriminant analysis was applied to the sugar data set in order to predict the origin of the foulant material. Three groups of various origins (algal, microbial, continental dissolved organic matter) were used as sugar references for the prediction. The results of the computation showed that the origin of reverse osmosis (RO) seawater foulant material is influenced by both the location of the water sources and the season. RO brackish water and nanofiltration river water foulant materials had a terrestrial origin. Secondly, bacteriohopanepolyol signatures indicated that RO seawater foulant material had a marine signature, RO brackish water foulant material had both a marine and a terrestrial origin and the nanofiltration river water foulant material contained only a terrestrial signature. © 2011 Taylor & Francis.

  17. Boron Removal in Seawater Reverse Osmosis System

    KAUST Repository

    Rahmawati, Karina

    2011-07-01

    Reverse osmosis successfully proves to remove more than 99% of solute in seawater, providing fresh water supply with satisfied quality. Due to some operational constraints, however, some trace contaminants removal, such as boron, cannot be achieved in one pass system. The stringent criterion for boron from World Health Organization (WHO) and Saudi Arabia local standard (0.5 mg/l) is hardly fulfilled by single pass sea water reverse osmosis (SWRO) plants. Some design processes have been proposed to deal with boron removal, but they are not economically efficient due to high energy and chemical consumption. The objective of this study was to study boron removal by different reverse osmosis membranes in two pH conditions, with and without antiscalant addition. Thus, it was expected to observe the possibility of operating single pass system and necessity to operate two pass system using low energy membrane. Five membrane samples were obtained from two different manufacturers. Three types of feed water pH were used, pH 8, pH 10, and pH 10 with antiscalant addition. Experiment was conducted in parallel to compare membrane performance from two manufacturers. Filtration was run with fully recycle mode for three days. Sample of permeate and feed were taken every 12 hours, and analyzed for their boron and TDS concentration. Membrane samples were also tested for their surface charge. The results showed that boron rejection increases as the feed pH increases. This was caused by dissociation of boric acid to negatively charged borate ion and more negatively charged membrane surface at elevated pH which enhance boron rejection. This study found that single pass reverse osmosis system, with and without elevating the pH, may not be possible to be applied because of two reasons. First, permeate quality in term of boron, does not fulfill WHO and local Saudi Arabia regulations. Second, severe scaling occurs due to operation in alkaline condition, since Ca and Mg concentration are

  18. Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

    OpenAIRE

    Lee, Byung-Sik

    2015-01-01

    The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO) membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst–Plank equation, which handles the convective flux, diffusive flux, and electromigration f...

  19. Osmosis and pervaporation in polyimide submicron microfluidic channel structures

    NARCIS (Netherlands)

    Eijkel, Jan C.T.; Bomer, Johan G.; van den Berg, Albert

    2005-01-01

    Osmosis and pervaporation of water through the roof of all-polyimide channels of 500 nm height is described. The phenomena cause both a liquid flow in the channels and a concentration change of dissolved salt. Both effects are amplified due to the thin channel roof and the small channel height.

  20. 3D morphological characterization of the polyamide active layer of RO and NF membranes using TEM and soft X-ray scattering

    Science.gov (United States)

    Culp, Tyler; Paul, Mou; Roy, Abhishek; Rosenberg, Steve; Behr, Michael; Kumar, Manish; Gomez, Enrique; Penn State Team; Dow Team

    Polyamide-based thin-film composite (TFC) membranes used for reverse osmosis (RO) and nanofiltration (NF) separation processes are at the forefront of water desalination and purification technologies due to their high salt rejection, high energy efficiency, and ease of operation. Nevertheless, in spite of the benefits of RO and NF membranes, many open questions about the internal nanostructure of the membrane active layer remain, such as the dispersion and distribution of acid functional groups. We demonstrate that resonant soft X-ray scattering (RSOXS), where the X-ray energy is tuned to absorption edges of the constituent materials, is a powerful tool to examine the microstructure of the polyamide layer. In conjunction with complementary techniques such as transmission electron microscopy (TEM), where tomography is used to obtain a 3D reconstruction of the polyamide active layer, the effect of cross-linking can be quantified in 3D for a systematic series of membranes. This relationship can then be applied to a series of commercially available RO and NF membranes where the effect of polyamide cross-linking on their respective structure and water transport properties can be evaluated. The combination of RSOXS with traditional characterization tools provides a strategy for linking the chemical structure to the morphology and water transport properties of RO and NF membranes.

  1. Modeling the effect of spacers and biofouling on forward osmosis performance

    KAUST Repository

    Mosqueira Santillán, María José

    2014-11-01

    Currently, the most utilized desalination technology is reverse osmosis (RO), where a membrane is used as a physical barrier to separate the salts from the seawater, using high hydraulic pressure as driving force. A major problem in RO systems is biofouling, caused by severe growth of bacterial biofilms. Both, the need of an external energy input, as well as biofouling, impose a high cost on RO operation. Forward osmosis (FO) is an alternative membrane process that uses an osmotic pressure difference as driving force. FO uses a concentrated draw solution to generate high osmotic pressure, which extracts water across a semi permeable membrane from a feed solution. One of the main advantages of FO is the limited amount of external energy required to extract water from the feed solution. The objective of this research is the assessment of the impact of spacers, separating the membrane sheets, and biofouling on the FO system performance. This type of studies allow the optimization of membrane devices and operational conditions. For this, a two dimensional numerical model for FO systems was developed using computational fluid dynamics (CFD). This model allowed the evaluation of the impact of (i) spacers and (ii) biofilm, and (iii) the combined impact of spacers and biofilm on the performance of FO systems. The results obtained showed that the presence of spacers improved the performance of FO systems. Cavity configuration spacer gave the higher water flux across the membrane in clean systems; whereas for biofouled systems, the submerged configuration showed a better performance. In absence of spacers, the thickness or amount of biofilm is inversely proportional with the water flux. Furthermore, membrane surface coverage of the biofilm is more important than the amount of biofilm in terms of the impact on the performance. The numerical model can be adapted with other parameters (e.g. membrane and spacer thickness, feed and draw solution, solution concentration, etc.) to

  2. Performance Limiting Effects in Power Generation from Salinity Gradients by Pressure Retarded Osmosis

    KAUST Repository

    Yip, Ngai Yin; Elimelech, Menachem

    2011-01-01

    Pressure retarded osmosis has the potential to utilize the free energy of mixing when fresh river water flows into the sea for clean and renewable power generation. Here, we present a systematic investigation of the performance limiting phenomena

  3. Unilever chooses a reverse osmosis system to improve efficiency and save energy

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2006-11-15

    Rising energy prices have created new energy efficiency practices at Unilever's plant in Rexdale, Ontario. In order to meet an aggressive goal of reducing energy consumption by at least 6 per cent per year, the plant's energy team has implemented and documented 120 projects since 1999, saving more than $4.2 million in energy costs while eliminating 23,000 tonnes of greenhouse gases (GHGs). The team recently consulted with GE Water and Process Technologies to investigate efficiency measures for their steam plant operations. After analyzing the cost of purchasing and treating water used to produce the 218 million pounds of steam that the plant uses each year, GE recommended a reverse osmosis (RO) system to replace the water softeners and chloride anion de-alkalizers that treated the municipal water used throughout the plant. RO is a mechanical process involving the reversal of flow through a semi-permeable membrane from a high salinity solution to a high purity stream on the opposite side of the membrane. Pressure is used as the driving force for the separation. A turnkey system was installed at the plant in 2005, which also recycles process water captured throughout the plant for use as boiler make-up. The RO feed water allows the boilers to operate at 100 feedwater cycles instead of 10, dramatically increasing energy efficiency. By converting to the RO system, the plant is now consuming 13 million gallons less of municipal water and 8 per cent less natural gas, for a total savings of $68,000 and $299,000 respectively per year. The plant is also saving $11,700 in boiler chemicals and $22,000 in commodity softening chemicals. The RO system has also qualified the Rexdale plant for a $50,000 incentive grant from the City of Toronto for decreased water consumption. It was concluded that while the project has provided financial benefit to Unilever, the company is equally proud of the environmental benefits of the system, which both reduces chemical use and the

  4. Thermodynamic and thermoeconomic analyses of seawater reverse osmosis desalination plant with energy recovery

    International Nuclear Information System (INIS)

    El-Emam, Rami Salah; Dincer, Ibrahim

    2014-01-01

    This paper investigates the performance of a RO (reverse osmosis) desalination plant at different seawater salinity values. An energy recovery Pelton turbine is integrated with the desalination plant. Thermodynamic analysis, based on the first and second laws of thermodynamics, as well as a thermo-based economic analysis is performed for the proposed system. The effects of the system components irreversibilities on the economics and cost of product water are parametrically studied through the thermoeconomic analysis. The exergy analysis shows that large irreversibilities occur in the high pressure pump and in the RO module. Both thermodynamic and thermoeconomic performances of the overall system are investigated under different operating parameters. For the base case; the system achieves an exergy efficiency of 5.82%. The product cost is estimated to be 2.451 $/m 3 and 54.2 $/MJ when source water with salinity of 35,000 ppm is fed to the system. - Highlights: • Thermodynamic and exergoeconomic analyses are performed for SWRO with energy recovery. • Parametric studies are done to study effects of operating conditions on performance. • Different seawater sources with different salinity values are tested. • At base case, plant exergy efficiency is 5.82% and product cost is 2.451 $/m 3

  5. In-situ Non-destructive Studies on Biofouling Processes in Reverse Osmosis Membrane Systems

    KAUST Repository

    Farhat, Nadia

    2016-12-01

    Reverse osmosis (RO) and nanofiltration (NF) membrane systems are high-pressure membrane filtration processes that can produce high quality drinking water. Biofouling, biofilm formation that exceeds a certain threshold, is a major problem in spiral wound RO and NF membrane systems resulting in a decline in membrane performance, produced water quality, and quantity. In practice, detection of biofouling is typically done indirectly through measurements of performance decline. Existing direct biofouling detection methods are mainly destructive, such as membrane autopsies, where biofilm samples can be contaminated, damaged and resulting in biofilm structural changes. The objective of this study was to test whether transparent luminescent planar oxygen sensing optodes, in combination with a simple imaging system, can be used for in-situ, non-destructive biofouling characterization. Aspects of the study were early detection of biofouling, biofilm spatial patterning in spacer filled channels, and the effect of feed cross-flow velocity, and feed flow temperature. Oxygen sensing optode imaging was found suitable for studying biofilm processes and gave detailed spatial and quantitative biofilm development information enabling better understanding of the biofouling development process. The outcome of this study attests the importance of in-situ, non-destructive imaging in acquiring detailed knowledge on biofilm development in membrane systems contributing to the development of effective biofouling control strategies.

  6. Calculation of separation selectivity of aqueous electrolytic solutions with reverse osmosis membranes

    International Nuclear Information System (INIS)

    Ognevskij, A.V.; Fomichev, S.V.; Khvostov, V.F.; Kochergin, N.V.; AN SSSR, Moscow

    1988-01-01

    Viscosity and dielectric permittivity of a bound water layer in micropores of cellulose acetate membranes used for electrolyte ion separation by reverse osmosis method are calculated using the water cluster model and the proposed structural temperature parameter. Based on the model representations presented an algorithmof reverse osmosis membrane selectivity calculation in diluted aqueous solutions ofelectrolytes containing Cs + , Sr 2+ , I - and other ions is constructed

  7. A technical and economic evaluation of reverse osmosis nuclear desalination as applied at the Muria site in Indonesia

    International Nuclear Information System (INIS)

    Humphries, J.R.; Davies, K.; Vu, T.D.; Aryono, N.A.; Peryoga, Y.

    1998-01-01

    In many regions of the world, the supply of renewable water resources is inadequate to meet current needs, and that from non-renewable sources is being rapidly depleted. Since the worldwide demand for potable water is steadily growing, the result is water shortages that are already reaching serious proportions in many regions. This is particularly true in Indonesia where there is an increasing reliance on bottled water due to shortage of safe, fresh drinking water. To mitigate the stress being placed on water resources, additional fresh water production capability must be developed. Because of Indonesia's long coastline, seawater desalination is a good alternative. The main drawback of desalination, however, is that it is an energy intensive process. Therefore, the increasing global demand for desalted water creates a tremendous collateral demand for new sources of electrical power. In addition to providing a means of meeting regional electricity demand, the CANDU nuclear reactor can also serve as an energy source for a reverse osmosis (RO) seawater desalination plant. In conjunction with the use of electrical energy, waste heat from the reactor is used in the desalination plant to improve the efficiency of the RO process. This is done by using condenser cooling water being discharged from the CANDU reactor as a source of preheated feedwater for the RO system. The system design also makes use of advanced feedwater pretreatment and sophisticated design optimization analyses. The net result is improved efficiency of energy utilization, increased potable water production capability, reduced product water cost and reduced environmental burden. This approach to the integration of a seawater desalination plant with a CANDU nuclear reactor has the advantage of maximizing the benefits of system integration while at the same time minimizing the impacts of physical interaction between the two systems. Consequently, transients in one plant do not necessarily have adverse

  8. Short Review on Predicting Fouling in RO Desalination

    Directory of Open Access Journals (Sweden)

    Alejandro Ruiz-García

    2017-10-01

    Full Text Available Reverse Osmosis (RO membrane fouling is one of the main challenges that membrane manufactures, the scientific community and industry professionals have to deal with. The consequences of this inevitable phenomenon have a negative effect on the performance of the desalination system. Predicting fouling in RO systems is key to evaluating the long-term operating conditions and costs. Much research has been done on fouling indices, methods, techniques and prediction models to estimate the influence of fouling on the performance of RO systems. This paper offers a short review evaluating the state of industry knowledge in the development of fouling indices and models in membrane systems for desalination in terms of use and applicability. Despite major efforts in this field, there are gaps in terms of effective methods and models for the estimation of fouling in full-scale RO desalination plants. In existing models applied to full-scale RO desalination plants, neither the spacer geometry of membranes, nor the efficiency and frequency of chemical cleanings are considered.

  9. Hydrophilic nanofibers as new supports for thin film composite membranes for engineered osmosis.

    Science.gov (United States)

    Bui, Nhu-Ngoc; McCutcheon, Jeffrey R

    2013-02-05

    Engineered osmosis (e.g., forward osmosis, pressure-retarded osmosis, direct osmosis) has emerged as a new platform for applications to water production, sustainable energy, and resource recovery. The lack of an adequately designed membrane has been the major challenge that hinders engineered osmosis (EO) development. In this study, nanotechnology has been integrated with membrane science to build a next generation membrane for engineered osmosis. Specifically, hydrophilic nanofiber, fabricated from different blends of polyacrylonitrile and cellulose acetate via electrospinning, was found to be an effective support for EO thin film composite membranes due to its intrinsically wetted open pore structure with superior interconnectivity. The resulting composite membrane exhibits excellent permselectivity while also showing a reduced resistance to mass transfer that commonly impacts EO processes due to its thin, highly porous nanofiber support layer. Our best membrane exhibited a two to three times enhanced water flux and 90% reduction in salt passage when compared to a standard commercial FO membrane. Furthermore, our membrane exhibited one of the lowest structural parameters reported in the open literature. These results indicate that hydrophilic nanofiber supported thin film composite membranes have the potential to be a next generation membrane for engineered osmosis.

  10. Forward Osmosis in India: Status and Comparison with Other Desalination Technologies

    Science.gov (United States)

    2014-01-01

    With an increase in demand of freshwater and depleting water sources, it is imperative to switch to seawater as a regular source of water supply. However, due to the high total dissolved solid content, it has to be desalinated to make it drinkable. While desalination technologies have been used for many years, mass deployment of such technologies poses a number of challenges like high energy requirements as well as high negative environmental impact through side products and CO2 emissions. The purpose of this paper is to present a sustainable technology for desalination. Forward osmosis, an emerging technology, is compared with the other commonly used technologies worldwide, namely, multieffect distillation, multistage flash distillation, and reverse osmosis as well as other emerging technologies like vapour compression, solar humidification dehumidification, nanofiltration, and freezing desalination. As energy consumption and associated greenhouse gas emissions are one of the major concerns of desalination, this paper concludes that forward osmosis is an emerging sustainable technology for seawater desalination. This paper then presents the challenges involved in the application of forward osmosis in India and presents a plant setup. In the end, the cost comparison of a forward osmosis and reverse osmosis plant has been done and it was concluded that forward osmosis is economically better as well. PMID:27350984

  11. Forward Osmosis in India: Status and Comparison with Other Desalination Technologies.

    Science.gov (United States)

    Mehta, Dhruv; Gupta, Lovleen; Dhingra, Rijul

    2014-01-01

    With an increase in demand of freshwater and depleting water sources, it is imperative to switch to seawater as a regular source of water supply. However, due to the high total dissolved solid content, it has to be desalinated to make it drinkable. While desalination technologies have been used for many years, mass deployment of such technologies poses a number of challenges like high energy requirements as well as high negative environmental impact through side products and CO2 emissions. The purpose of this paper is to present a sustainable technology for desalination. Forward osmosis, an emerging technology, is compared with the other commonly used technologies worldwide, namely, multieffect distillation, multistage flash distillation, and reverse osmosis as well as other emerging technologies like vapour compression, solar humidification dehumidification, nanofiltration, and freezing desalination. As energy consumption and associated greenhouse gas emissions are one of the major concerns of desalination, this paper concludes that forward osmosis is an emerging sustainable technology for seawater desalination. This paper then presents the challenges involved in the application of forward osmosis in India and presents a plant setup. In the end, the cost comparison of a forward osmosis and reverse osmosis plant has been done and it was concluded that forward osmosis is economically better as well.

  12. Synthesis of robust and high-performance aquaporin-based biomimetic membranes by interfacial polymerization-membrane preparation and RO performance characterization

    DEFF Research Database (Denmark)

    Zhao, Yang; Qiu, Changquan; Li, Xuesong

    2012-01-01

    -free ABMs that can be easily scaled up. In the current study, a thin film composite (TFC) ABM was prepared by the interfacial polymerization method, where AquaporinZ-containing proteoliposomes were added to the m-phenylene-diamine aqueous solution. Control membranes, either without aquaporins......Aquaporins are water channel proteins with excellent water permeability and solute rejection, which makes them promising for preparing high-performance biomimetic membranes. Despite the growing interest in aquaporin-based biomimetic membranes (ABMs), it is challenging to produce robust and defect...... or with inactive (mutant) aquaporins, were also similarly prepared. The separation performance of these membranes was evaluated by cross-flow reverse osmosis (RO) tests. Compared to the controls, the active ABM achieved significantly higher water permeability (∼4L/m2hbar) with comparable NaCl rejection (∼97...

  13. Multi-objective optimization of a pressurized solid oxide fuel cell – gas turbine hybrid system integrated with seawater reverse osmosis

    International Nuclear Information System (INIS)

    Eveloy, Valerie; Rodgers, Peter; Al Alili, Ali

    2017-01-01

    To improve the capacity and efficiency of distributed power and fresh water generation in coastal industrial facilities affected by regional water scarcity, a natural gas-fueled, pressurized solid oxide fuel cell-gas turbine (SOFC-GT) hybrid is integrated with a bottoming organic Rankine cycle (ORC) and seawater reverse osmosis (RO) desalination plant. This power and water co-generation system is optimized in terms of two objectives, maximum exergy efficiency and minimum cost rate, using a genetic algorithm. The exergetic and economic performance of three solutions representing maximum exergy efficiency, minimum cost rate, and a compromise between efficiency and cost rate, are compared. When imposing a water production requirement (reference case), the selected compromise multi-objective optimization solution delivers a net power output of 2.4 MWe and 636 m"3/day of permeate, at a co-generation exergy efficiency and cost rate of 71.3% and 0.0256 USD/s, respectively. The system payback time is estimated to be less than six years for typical economic parameters, but would become unprofitable in the most unfavorable economic scenario considered. Overall, the results indicate the thermodynamic and economic benefits of reverse osmosis over thermal desalination processes for integration with high-efficiency power generation systems in coastal regions impacted by domestic gas shortages and water scarcity. - Highlights: • Integration of a pressurized SOFC-GT hybrid system with a reverse osmosis unit. • Multi-objective, exergetic and economic optimization using a genetic algorithm. • Optimum solution delivers 2.4 MWe and 636 m"3/day of desalinated water. • Overall exergy efficiency and cost rate of 71.3% and 0.0256 USD/s, respectively. • System payback time estimated at less than six years for typical economic conditions.

  14. Osmosis in Cortical Collecting Tubules

    Science.gov (United States)

    Schafer, James A.; Troutman, Susan L.; Andreoli, Thomas E.

    1974-01-01

    The present experiments were designed to evaluate the effects of varying the osmolality of luminal solutions on the antidiuretic hormone (ADH)-independent water and solute permeability properties of isolated rabbit cortical collecting tubules. In the absence of ADH, the osmotic water permeability coefficient (cm s–1) Pfl→b, computed from volume flows from hypotonic lumen to isotonic bath, was 20 ± 4 x 10–4 (SEM); the value of Pfb→l in the absence of ADH, computed from volume flows from isotonic bath to hypertonic lumen, was 88 ± 15 x 10–4 cm s–1. We also measured apparent urea permeability coefficients (cm s–1) from 14C-urea fluxes from lumen to bath (P DDurea l→b) and from bath to lumen (P DDurea b→l). For hypotonic luminal solutions and isotonic bathing solutions, P DDurea l→b was 0.045 ± 0.004 x 10–4 and was unaffected by ADH. The ADH-independent values of P DDurea l→b and P urea b→l were, respectively, 0.216 ± 0.022 x 10–4 cm s–1 and 0.033 ± 0.002 x 10–4 cm s–1 for isotonic bathing solutions and luminal solutions made hypertonic with urea, i.e., there was an absolute increase in urea permeability and asymmetry of urea fluxes. Significantly, P DDurea l→b did not rise when luminal hypertonicity was produced by sucrose; and, bathing fluid hypertonicity did not alter tubular permeability to water or to urea. We interpret these data to indicate that luminal hypertonicity increased the leakiness of tight junctions to water and urea but not sucrose. Since the value of Pfb→l in the absence of ADH, when tight junctions were open to urea, was approximately half of the value of Pfl→b in the presence of ADH, when tight junctions were closed to urea, we conclude that tight junctions are negligible paracellular shunts for lumen to bath osmosis with ADH. These findings, together with those in the preceding paper, are discussed in terms of a solubility-diffusion model for water permeation in which ADH increases water solubility in

  15. Impact of spacer thickness on biofouling in forward osmosis

    KAUST Repository

    Valladares Linares, Rodrigo

    2014-06-01

    Forward osmosis (FO) indirect desalination systems integrate wastewater recovery with seawater desalination. Niche applications for FO systems have been reported recently, due to the demonstrated advantages compared to conventional high-pressure membrane processes such as nanofiltration (NF) and reverse osmosis (RO). Among them, wastewater recovery has been identified to be particularly suitable for practical applications. However, biofouling in FO membranes has rarely been studied in applications involving wastewater effluents. Feed spacers separating the membrane sheets in cross-flow systems play an important role in biofilm formation. The objective of this study was to determine the influence of feed spacer thickness (28, 31 and 46mil) on biofouling development and membrane performance in a FO system, using identical cross-flow cells in parallel studies. Flux development, biomass accumulation, fouling localization and composition were determined and analyzed. For all spacer thicknesses, operated at the same feed flow and the same run time, the same amount of biomass was found, while the flux reduction decreased with thicker spacers. These observations are in good agreement with biofouling studies for RO systems, considering the key differences between FO and RO. Our findings contradict previous cross-flow studies on particulate/colloidal fouling, where higher cross-flow velocities improved system performance. Thicker spacers reduced the impact of biofouling on FO membrane flux. © 2014 Elsevier Ltd.

  16. Impact of spacer thickness on biofouling in forward osmosis.

    Science.gov (United States)

    Valladares Linares, R; Bucs, Sz S; Li, Z; AbuGhdeeb, M; Amy, G; Vrouwenvelder, J S

    2014-06-15

    Forward osmosis (FO) indirect desalination systems integrate wastewater recovery with seawater desalination. Niche applications for FO systems have been reported recently, due to the demonstrated advantages compared to conventional high-pressure membrane processes such as nanofiltration (NF) and reverse osmosis (RO). Among them, wastewater recovery has been identified to be particularly suitable for practical applications. However, biofouling in FO membranes has rarely been studied in applications involving wastewater effluents. Feed spacers separating the membrane sheets in cross-flow systems play an important role in biofilm formation. The objective of this study was to determine the influence of feed spacer thickness (28, 31 and 46 mil) on biofouling development and membrane performance in a FO system, using identical cross-flow cells in parallel studies. Flux development, biomass accumulation, fouling localization and composition were determined and analyzed. For all spacer thicknesses, operated at the same feed flow and the same run time, the same amount of biomass was found, while the flux reduction decreased with thicker spacers. These observations are in good agreement with biofouling studies for RO systems, considering the key differences between FO and RO. Our findings contradict previous cross-flow studies on particulate/colloidal fouling, where higher cross-flow velocities improved system performance. Thicker spacers reduced the impact of biofouling on FO membrane flux. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Impact of spacer thickness on biofouling in forward osmosis

    KAUST Repository

    Valladares Linares, Rodrigo; Bucs, Szilard; Li, Z.; AbuGhdeeb, M.; Amy, Gary L.; Vrouwenvelder, Johannes S.

    2014-01-01

    Forward osmosis (FO) indirect desalination systems integrate wastewater recovery with seawater desalination. Niche applications for FO systems have been reported recently, due to the demonstrated advantages compared to conventional high-pressure membrane processes such as nanofiltration (NF) and reverse osmosis (RO). Among them, wastewater recovery has been identified to be particularly suitable for practical applications. However, biofouling in FO membranes has rarely been studied in applications involving wastewater effluents. Feed spacers separating the membrane sheets in cross-flow systems play an important role in biofilm formation. The objective of this study was to determine the influence of feed spacer thickness (28, 31 and 46mil) on biofouling development and membrane performance in a FO system, using identical cross-flow cells in parallel studies. Flux development, biomass accumulation, fouling localization and composition were determined and analyzed. For all spacer thicknesses, operated at the same feed flow and the same run time, the same amount of biomass was found, while the flux reduction decreased with thicker spacers. These observations are in good agreement with biofouling studies for RO systems, considering the key differences between FO and RO. Our findings contradict previous cross-flow studies on particulate/colloidal fouling, where higher cross-flow velocities improved system performance. Thicker spacers reduced the impact of biofouling on FO membrane flux. © 2014 Elsevier Ltd.

  18. Development of the pilot system for radioactive laundry waste treatment using UV photo-oxidation process and reverse osmosis membrane

    International Nuclear Information System (INIS)

    Park, S. M.; Park, J. K.; Kim, J. B.; Shin, S. W.; Lee, M. C.

    1999-01-01

    The pilot system for radioactive liquid laundry waste was developed with treatment capacity 1ton/hr and set up in the Yonkwang unit No.4. The system is composed of tank module, reverse osmosis membrane system and UV/H2O2 photo-oxidation process unit. The R/O system consists of the BW unit for low concentration and the SW unit for high concentration. The BW unit possesses 4 of R/O membranes and it can concentrate the feed water volume down to 1/10. This concentrated feed water can be reduced again 1/10 in its volume in the SW unit which is composed of 4 of R/O membranes. The UV/H2O2 photo-oxidation process unit was determined for the detergent removal process. The pilot system was verified in its capability through the continuous operation and enrichment operation using the actual liquid waste of the power plant. The design criteria and data for the industrial system were yielded. The efficiency of the UV/H2O2 photo-oxidation process and the optimum operational procedure were analysed. The decontamination factor of radionuclides, cobalt and cesium was measured. This on-site test showed the experimental result of the DF more than 100 and concentration rate more than 100

  19. Design features of a reverse osmosis demonstration plant for treatment of low level radioactive waste

    International Nuclear Information System (INIS)

    Shekhar, P.; Sudesh Nath; Gandhi, P.M.; Mishra, S.D.

    1994-01-01

    Reverse osmosis, a novel process in the field of nuclear waste management, is under evaluation globally. Its application is basically considered for the treatment of low level waste; yet references are found for its possible use to treat specific intermediate level waste streams, if segregated at source. The process of reverse osmosis (RO) is proposed for use in conjunction with other conventional processes like chemical treatment, ion exchange and evaporation. Flow sheets have been developed wherein RO can come as a replacement of one of these processes or is used as a pre or post treatment stage. The emphasis is on reducing the secondary wastes so as to realize an optimum levelised cost of treatment. This paper outlines the design basis for an RO plant for treating low level radioactive wastes based on the studies carried out on laboratory as well as bench scale. (author)

  20. Design features of a reverse osmosis demonstration plant for treatment of low level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, P; Nath, Sudesh; Gandhi, P M; Mishra, S D [Waste Management Projects Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    Reverse osmosis, a novel process in the field of nuclear waste management, is under evaluation globally. Its application is basically considered for the treatment of low level waste; yet references are found for its possible use to treat specific intermediate level waste streams, if segregated at source. The process of reverse osmosis (RO) is proposed for use in conjunction with other conventional processes like chemical treatment, ion exchange and evaporation. Flow sheets have been developed wherein RO can come as a replacement of one of these processes or is used as a pre or post treatment stage. The emphasis is on reducing the secondary wastes so as to realize an optimum levelised cost of treatment. This paper outlines the design basis for an RO plant for treating low level radioactive wastes based on the studies carried out on laboratory as well as bench scale. (author). 3 figs., 3 tabs.

  1. Solvents in membrane synthesis and their effect on NF/RO performance: from conventional organic solvents to ionic liquids:Solventen in membraansynthese en hun effect op NF/RO performantie: van conventionele organische solventen naar ionische vloeistoffen

    OpenAIRE

    Mariën, Hanne

    2017-01-01

    Membrane technology has grown significantly over the last decades and is used in a broad range of applications nowadays. Nanofiltration (NF) and reverse osmosis (RO) are applied for the separation of low molecular weight components (< 1000 Da) and salts from the feed stream. The main part of the commercial NF and RO membranes are either integrally skinned asymmetric (ISA) or interfacially polymerized thin film composite (TFC) membranes. Polyamide (PA) TFC membranes are the standard in aqueous...

  2. Flow cytometric assessment of microbial abundance in the near-field area of seawater reverse osmosis concentrate discharge

    KAUST Repository

    Van Der Merwe, Riaan; Hammes, Frederik A.; Lattemann, Sabine; Amy, Gary L.

    2014-01-01

    The discharge of concentrate and other process waters from seawater reverse osmosis (SWRO) plant operations into the marine environment may adversely affect water quality in the near-field area surrounding the outfall. The main concerns

  3. Environmental Performance Evaluation of Ro-Ro Passenger Ferry Transportation

    DEFF Research Database (Denmark)

    Kristensen, Hans Otto Holmegaard; Hagemeister, Constantin

    2012-01-01

    /or emissions per transport unit, is related to the same unit for the different transport forms. For Ro-Ro passenger ferries it can be difficult to find a suitable common transport unit, as they often transport a mix of cargo, such as passengers, passenger cars, trucks, lorries, busses and other rolling...

  4. Solar Desalination System Model for Sizing of Photovoltaic Reverse Osmosis (PVRO)

    KAUST Repository

    Habib, Abdulelah

    2015-06-28

    The focus of this paper is to optimize the solar energy utilization in the water desalination process. Due to variable nature of solar energy, new system design is needed to address this challenge. Here, reverse osmosis units, as the electrical loads, are considered as an ON/OFF units to track these solar energy variations. Reverse osmosis units are different in sizes and numbers. Various combinations of reverse osmosis units in size and capacity provide different water desalination system performances. To assess each scenario of reverse osmosis units, the total capital cost and operation and maintenance (O&M) cost are considered. The implemented optimization algorithm search all of the possible scenarios to find the best solution. This paper deploys the solar irradiance data which is provided from west coast (Red Sea) of Saudi Arabia for model construction and optimization algorithm implementation.

  5. Coating of reverse osmosis membranes with amphiphilic copolymers for biofouling control

    KAUST Repository

    Bucs, Szilard

    2017-05-30

    Surface coating of membranes may be a promising option to control biofilm development and biofouling impact on membrane performance of spiral-wound reverse osmosis (RO) systems. The objective of this study was to investigate the impact of an amphiphilic copolymer coating on biofilm formation and biofouling control. The coating was composed of both hydrophilic and hydrophobic monomers hydroxyethyl methacrylate (HEMA) and perfluorodecyl acrylate (PFA), respectively. Commercial RO membranes were coated with HEMA-PFA copolymer film. Long and short term biofouling studies with coated and uncoated membranes and feed spacer were performed using membrane fouling simulators (MFSs) operated in parallel, fed with water containing nutrients. For the long-term studies pressure drop development in time was monitored and after eight days the MFSs were opened and the accumulated biofilm on the membrane and spacer sheets was quantified and characterized. The presence of the membrane coating was determined using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Results showed that the amphiphilic coating (i) delayed biofouling (a lower pressure drop increase by a factor of 3 and a lower accumulated active biomass amount by a factor of 6), (ii) influenced the biofilm composition (23% lower polysaccharides and 132% higher protein content) and (iii) was still completely present on the membrane at the end of the biofouling study, showing that the coating was strongly attached to the membrane surface. Using coated membranes and feed spacers in combination with advanced cleaning strategies may be a suitable way to control biofouling.

  6. Changes in physicochemical and transport properties of a reverse osmosis membrane exposed to chloraminated seawater

    KAUST Repository

    Valentino, Lauren; Renkens, Tennie; Maugin, Thomas; Crouè , Jean-Philippe Philippe; Mariñ as, Benito J.

    2015-01-01

    This study contributed to improving our understanding of how disinfectants, applied to control biofouling of reverse osmosis (RO) membranes, result in membrane performance degradation. We investigated changes in physicochemical properties and permeation performance of a RO membrane with fully aromatic polyamide (PA) active layer. Membrane samples were exposed to varying concentrations of monochloramine, bromide, and iodide in both synthetic and natural seawater. Elemental analysis of the membrane active layer by Rutherford backscattering spectrometry (RBS) revealed the incorporation of bromine and iodine into the polyamide. The kinetics of polyamide bromination were first order with respect to the concentration of the secondary oxidizing agent Br2 for the conditions investigated. Halogenated membranes were characterized after treatment with a reducing agent and heavy ion probes to reveal the occurrence of irreversible ring halogenation and an increase in carboxylic groups, the latter produced as a result of amide bond cleavage. Finally, permeation experiments revealed increases in both water permeability and salt passage as a result of oxidative damage.

  7. Recycling of end-of-life reverse osmosis membranes by oxidative treatment: a technical evaluation.

    Science.gov (United States)

    Coutinho de Paula, Eduardo; Gomes, Júlia Célia Lima; Amaral, Míriam Cristina Santos

    2017-07-01

    The adverse impacts caused by the disposal of thousands of tonnes per annum of reverse osmosis (RO) membranes modules have grown dramatically around the world. The objective of this study was to evaluate the technical feasibility of recycling by chemical oxidation of end-of-life RO membranes for applications in other separation processes with specifications less rigorous. The recycling technique consisted in to cause a membrane exposition with oxidant solutions in order to remove its aromatic polyamide layer and subsequent conversion to a porous membrane. The recycling technique was evaluated by water permeability and salt rejection tests before and after the oxidative treatments. Initially, membranes' chemical cleaning and pretreatment procedures were assessed. Among factors evaluated, the oxidizing agent, its concentration and pH, associated with the oxidative treatment time, showed important influence on the oxidation of the membranes. Results showed that sodium hypochlorite and potassium permanganate are efficient agents for the membrane recycling. The great increased permeability and decreased salt rejection indicated changes on membranes' selective properties. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and contact angle characterization techniques revealed marked changes on the main membranes' physical-chemical properties, such as morphology, roughness and hydrophobicity. Reuse of produced effluents and fouling tendency of recycled membranes were also evaluated.

  8. Coating of reverse osmosis membranes with amphiphilic copolymers for biofouling control

    KAUST Repository

    Bucs, Szilard; Valladares Linares, Rodrigo; Siddiqui, Amber; Matin, Asif; Khan, Zafarullah; van Loosdrecht, Mark C.M.; Yang, Rong; Wang, Minghui; Gleason, Karen K.; Kruithof, Joop C.; Vrouwenvelder, Johannes S.

    2017-01-01

    Surface coating of membranes may be a promising option to control biofilm development and biofouling impact on membrane performance of spiral-wound reverse osmosis (RO) systems. The objective of this study was to investigate the impact of an amphiphilic copolymer coating on biofilm formation and biofouling control. The coating was composed of both hydrophilic and hydrophobic monomers hydroxyethyl methacrylate (HEMA) and perfluorodecyl acrylate (PFA), respectively. Commercial RO membranes were coated with HEMA-PFA copolymer film. Long and short term biofouling studies with coated and uncoated membranes and feed spacer were performed using membrane fouling simulators (MFSs) operated in parallel, fed with water containing nutrients. For the long-term studies pressure drop development in time was monitored and after eight days the MFSs were opened and the accumulated biofilm on the membrane and spacer sheets was quantified and characterized. The presence of the membrane coating was determined using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Results showed that the amphiphilic coating (i) delayed biofouling (a lower pressure drop increase by a factor of 3 and a lower accumulated active biomass amount by a factor of 6), (ii) influenced the biofilm composition (23% lower polysaccharides and 132% higher protein content) and (iii) was still completely present on the membrane at the end of the biofouling study, showing that the coating was strongly attached to the membrane surface. Using coated membranes and feed spacers in combination with advanced cleaning strategies may be a suitable way to control biofouling.

  9. Changes in physicochemical and transport properties of a reverse osmosis membrane exposed to chloraminated seawater

    KAUST Repository

    Valentino, Lauren

    2015-02-17

    This study contributed to improving our understanding of how disinfectants, applied to control biofouling of reverse osmosis (RO) membranes, result in membrane performance degradation. We investigated changes in physicochemical properties and permeation performance of a RO membrane with fully aromatic polyamide (PA) active layer. Membrane samples were exposed to varying concentrations of monochloramine, bromide, and iodide in both synthetic and natural seawater. Elemental analysis of the membrane active layer by Rutherford backscattering spectrometry (RBS) revealed the incorporation of bromine and iodine into the polyamide. The kinetics of polyamide bromination were first order with respect to the concentration of the secondary oxidizing agent Br2 for the conditions investigated. Halogenated membranes were characterized after treatment with a reducing agent and heavy ion probes to reveal the occurrence of irreversible ring halogenation and an increase in carboxylic groups, the latter produced as a result of amide bond cleavage. Finally, permeation experiments revealed increases in both water permeability and salt passage as a result of oxidative damage.

  10. Osmosis in Poisoned Plant Cells.

    Science.gov (United States)

    Tatina, Robert

    1998-01-01

    Describes two simple laboratory exercises that allow students to test hypotheses concerning the requirement of cell energy for osmosis. The first exercise involves osmotically-caused changes in the length of potato tubers and requires detailed quantitative observations. The second exercise involves osmotically-caused changes in turgor of Elodea…

  11. Osmosis and the Marvelous Membrane.

    Science.gov (United States)

    Cocanour, Barbara; Bruce, Alease S.

    1985-01-01

    Shows how the natural membrane of a decalcified chicken egg can demonstrate the principle of osmosis within a single class period. Various glucose and saline solutions used, periods of time, physiological effects experiments, and correction for differences in initial weights are noted. (DH)

  12. Problem Solvers' Conceptions about Osmosis.

    Science.gov (United States)

    Zuckerman, June T.

    1994-01-01

    Discusses the scheme and findings of a study designed to identify the conceptual knowledge used by high school students to solve a significant problem related to osmosis. Useful tips are provided to teachers to aid students in developing constructs that maximize understanding. (ZWH)

  13. Batteryless photovoltaic reverse-osmosis desalination system

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, M.; Miranda, M.; Gwillim, J.; Rowbottom, A.; Draisey, I.

    2001-07-01

    The aim of this project was to design an efficient cost-effective batteryless photovoltaic-powered seawater reverse-osmosis desalination system, to deliver in the order of 3 m{sup 3} of fresh drinking water per day. The desalination of seawater to produce fresh drinking water is extremely valuable on islands and in coastal regions wherever natural freshwater is scarce. Existing small-scale desalination equipment, suitable for areas of medium and low population density, often requires a copious and constant supply of energy, either electricity or diesel. If supply of these fuels is expensive or insecure, but the area has a good solar resource, the use of photovoltaic power is an attractive option. Existing demonstrations of photovoltaic-powered desalination generally employ lead-acid batteries, which allow the equipment to operate at a constant flow, but are notoriously problematic in practice. The system developed in this project runs at variable flow, enabling it to make efficient use of the naturally varying solar resource, without need of batteries. In a sense, the freshwater tank is providing the energy storage. In this project, we have reviewed the merits of a wide variety of reverse-osmosis system configurations and component options. We have completed extensive in-house testing and characterisation of major hardware components and used the results to construct detailed software models. Using these, we have designed a system that meets the above project aim, and we have predicted its performance in detail. Our designs show that a system costing 23,055 pounds stirling will produce 1424 m{sup 3} of fresh drinking water annually - an average of just over 3.9 m{sup 3}/day. The system has no fuel costs and no batteries. The overall cost of water, including full maintenance, is 2.00 pounds stirling per m{sup 3}. The energy consumption (photovoltaic-electricity) is typically between 3.2 and 3.7 kWh/m{sup 3} depending on the solar irradiance and feed water

  14. Nuclear liquid wastes treatment: study of the reverse osmosis membranes degradation under γ irradiation

    International Nuclear Information System (INIS)

    Combernoux, Nicolas

    2015-01-01

    The treatment of nuclear liquid wastes by reverse osmosis (RO) involved issues of the water radiolysis and the membrane ageing due to γ irradiation effects. Membrane performances (permeability, strontium and cesium retention) were assessed after γ irradiation. Irradiation was carried out with an external 60 Co source in different conditions that simulated real used of the process (dose from 0.1 to 1 MGy, dose rate of 0.5 and 5 kGy.h -1 , with or without oxygen or water). Several analytical methods were performed to evaluate irradiation effects (ATR-FTIR, XPS, gas production, water soluble species released from the membrane). The methodology developed led to relevant information due to an innovative analytical protocol. Membrane performances started dropping between 0.2 and 0.5 MGy with oxygen and water (dose rate 0.5 kGy.h -1 ). This shift was linked to chains scissions inside the membrane active layer. The membrane degradation was weaker without oxygen or water or at high dose rate (5 kGy.h -1 ). Results showed that each analysis comforted each other. Membrane performances were also evaluated with three different types of liquid effluents, representing radioactive effluents from a post-disaster situation (groundwater type), disaster situation (seawater) or process water. Experiments were carried out at lab and pilot scales. Results indicated that the treatment of each effluent was possible by RO with an adequate choice of membrane and operating parameters. Finally, the time to reach an integrated dose threshold for the membrane in real conditions was estimated with the RABBI software: a dozen of days in the case of disaster situation to several years in the two other cases. (author) [fr

  15. Fresh Water Technology

    International Nuclear Information System (INIS)

    Ko, Yang Mun; Kim, O Sik; Kim, Jin Nam; Kim, Cheol Su

    1985-02-01

    This book tells US summary of fresh water with evaporation system like basic principle and outline, multistage flash evaporation, multiple-effect evaporation, other evaporation, evaporation plant by development merger, design of evaporation plant, reverse osmosis on summary, type and production of membrane, reverse osmosis device, reverse osmosis process, electrodialysis with outline of electrodialysis and polarization and energy, freezing preservation and corrosion and scale.

  16. Vacancy profile in reverse osmosis membranes studied by positron annihilation lifetime measurements and molecular dynamics simulations

    International Nuclear Information System (INIS)

    Shimazu, A; Shintani, T; Hirose, M; Goto, H; Suzuki, R; Kobayashi, Y

    2013-01-01

    The positron annihilation technique using a slow positron beam can be used for the study of the vacancy profiles in typical reverse osmosis (RO) membranes. In this study, the vacancy profile in the polyamide membrane that exhibits a high permselectivity between ions and water was studied using the positron annihilation technique and molecular dynamics simulations. Ortho-positronium (o-Ps) lifetimes in the surface region of the membranes were evaluated by using a slow positron beam. The diffusion behavior of Na + and water in the polyamides was simulated by molecular dynamics (MD) methods using the TSUBAME2 supercomputer at the Tokyo Institute of Technology and discussed with the vacancy profile probed by the o-Ps. The results suggested that the large hydration size of Na + compared to the vacancy size in the polyamides contributes to the increased diffusivity selectivity of water/Na + that is related to the NaCl desalination performance of the membrane. Both the hydration size of the ions and the vacancy size appeared to be significant parameters to discuss the diffusivity selectivity of water/ions in typical polyamide membranes.

  17. Optimisation of the cleaning sequence for reverse osmosis membranes; Optimizacion de secuencias de lavado de membranas de osmosis inversa

    Energy Technology Data Exchange (ETDEWEB)

    Hassani Zerrouk, M.; Quiroga Alonso, J. M.; Lopez Ramirez, J. A.

    2005-07-01

    Membranes used in water treatment lose performance along the time, in according to membrane kind, feed water characteristics and operating conditions. Fouling is the most important issue associated to membrane technology and for minimising it is necessary to clean membranes correctly. The main goal of this paper is to describe procedures and products that allow effective cleaning of reverse osmosis membranes, used to treat secondary effluents from activated sludges, which lead to a decrease in plant exploitation costs. (Author) 9 refs.

  18. How different is the composition of the fouling layer of wastewater reuse and seawater desalination RO membranes?

    KAUST Repository

    Khan, Muhammad; Busch, Markus; Molina, Veró nica Garcí a; Emwas, Abdul-Hamid M.; Aubry, Cyril; Croue, Jean-Philippe

    2014-01-01

    To study the effect of water quality and operating parameters on membrane fouling, a comparative analysis of wastewater (WW) and seawater (SW) fouled reverse osmosis (RO) membranes was conducted. Membranes were harvested from SWRO and WWRO pilot plants located in Vilaseca (East Spain), both using ultrafiltration as pretreatment. The SWRO unit was fed with Mediterranean seawater and the WWRO unit was operated using secondary effluent collected from the municipal wastewater treatment plant. Lead and terminal SWRO and WWRO modules were autopsied after five months and three months of operation, respectively. Ultrastructural, chemical, and microbiological analyses of the fouling layers were performed. Results showed that the WWRO train had mainly bio/organic fouling at the lead position element and inorganic fouling at terminal position element, whereas SWRO train had bio/organic fouling at both end position elements. In the case of WWRO membranes, Betaproteobacteria was the major colonizing species; while Ca, S, and P were the major present inorganic elements. The microbial population of SWRO membranes was mainly represented by Alpha and Gammaproteobacteria. Ca, Fe, and S were the main identified inorganic elements of the fouling layer of SWRO membranes. These results confirmed that the RO fouling layer composition is strongly impacted by the source water quality. © 2014 Elsevier Ltd.

  19. How different is the composition of the fouling layer of wastewater reuse and seawater desalination RO membranes?

    KAUST Repository

    Khan, Muhammad

    2014-08-01

    To study the effect of water quality and operating parameters on membrane fouling, a comparative analysis of wastewater (WW) and seawater (SW) fouled reverse osmosis (RO) membranes was conducted. Membranes were harvested from SWRO and WWRO pilot plants located in Vilaseca (East Spain), both using ultrafiltration as pretreatment. The SWRO unit was fed with Mediterranean seawater and the WWRO unit was operated using secondary effluent collected from the municipal wastewater treatment plant. Lead and terminal SWRO and WWRO modules were autopsied after five months and three months of operation, respectively. Ultrastructural, chemical, and microbiological analyses of the fouling layers were performed. Results showed that the WWRO train had mainly bio/organic fouling at the lead position element and inorganic fouling at terminal position element, whereas SWRO train had bio/organic fouling at both end position elements. In the case of WWRO membranes, Betaproteobacteria was the major colonizing species; while Ca, S, and P were the major present inorganic elements. The microbial population of SWRO membranes was mainly represented by Alpha and Gammaproteobacteria. Ca, Fe, and S were the main identified inorganic elements of the fouling layer of SWRO membranes. These results confirmed that the RO fouling layer composition is strongly impacted by the source water quality. © 2014 Elsevier Ltd.

  20. Biofouling in reverse osmosis: phenomena, monitoring, controlling and remediation

    Science.gov (United States)

    Maddah, Hisham; Chogle, Aman

    2017-10-01

    This paper is a comprehensive review of biofouling in reverse osmosis modules where we have discussed the mechanism of biofouling. Water crisis is an issue of pandemic concern because of the steady rise in demand of drinking water. Overcoming biofouling is vital since we need to optimize expenses and quality of potable water production. Various kinds of microorganisms responsible for biofouling have been identified to develop better understanding of their attacking behavior enabling us to encounter the problem. Both primitive and advanced detection techniques have been studied for the monitoring of biofilm development on reverse osmosis membranes. Biofouling has a negative impact on membrane life as well as permeate flux and quality. Thus, a mathematical model has been presented for the calculation of normalized permeate flux for evaluating the extent of biofouling. It is concluded that biofouling can be controlled by the application of several physical and chemical remediation techniques.

  1. Forward osmosis biomimetic membranes in industrial and environmental applications

    DEFF Research Database (Denmark)

    Bajraktari, Niada; Madsen, Henrik Tækker; Nielsen, K. H.

    consumption and lead to much more stable operations, but is currently limited by the availability of suitable membranes. However, by introducing aquaporin protein channels into a polymeric membrane to make a biomimetic membrane, the vision of both high flux and separation efficiency may be achieved......) a single use filtration module containing a sample reservoir and a biomimetic aquaporin based forward osmosis membrane. 2) a multi-use desktop forward osmosis system containing draw solution mixing, and monitoring devices. The sample is placed in the single use module and the module is then mounted...... a simple unit operation based on osmotic extraction of water from dilute peptide samples with no – or very little loss of sample material. A big challenge in modern water treatment is the handling of micropollutants. One example of these is the pollution of ground-/drinking water with pesticides, which...

  2. Evaluation the potential and energy efficiency of dual stage pressure retarded osmosis process

    International Nuclear Information System (INIS)

    Altaee, Ali; Zaragoza, Guillermo; Drioli, Enrico; Zhou, John

    2017-01-01

    Highlights: •Single and dual stage PRO was evaluated at different membrane configurations. •Impact of increasing module area or numbers on the power efficiency was studied. •DSPRO reduced the impact of CP & restored the osmotic potential of salinity gradient. •DSPRO outperforms single stage PRO process but depends on salinity gradient type. -- Abstract: Power generation by means of Pressure Retarded Osmosis (PRO) has been proposed for harvesting the energy of a salinity gradient. Energy recovery by the PRO process decreases along the membrane module due to depleting of the chemical potential across the membrane and concentration polarization effects. A dual stage PRO (DSPRO) design can be used to rejuvenate the chemical potential difference and reduce the concentration polarization on feed solution. Several design configurations were suggested for the membrane module arrangements in the first and second stage of the PRO process. PRO performance was evaluated for a number of salinity gradients proposed by coupling Dead Sea water or Reverse Osmosis (RO) brine with seawater or wastewater effluent. Maximum specific energy of inlet and outlet feeds was calculated using a developed computer model to identify the amount of recovered and remaining energy. Initially, specific power generation by the PRO process increased by increasing the number of modules of the first stage. Maximum specific energy is calculated along the PRO module to understand the degradation of the maximum specific energy in each module before introducing a second stage PRO process. Adding a second stage PRO process resulted in a sharp increase of the chemical potential difference and the specific energy yield of the process. Between 10% and 13% increase of the specific power generation was achieved by the DSPRO process for the Dead Sea-seawater salinity gradient depending on the dual stage design configuration. For Dead Sea-RO brine, 12–16% increase of the specific power generation was

  3. In situ chemical osmosis experiment in the Boom Clay at the Mol underground research laboratory

    Science.gov (United States)

    Garavito, A. M.; De Cannière, P.; Kooi, H.

    Studies on the compatibility of Boom Clay with large amounts of nitrate- bearing bituminized radioactive waste have recently raised a particular interest for osmosis-induced effects in this reference formation in Belgium. Indeed, water flow and solute transport may be associated with several types of driving forces, or gradients (chemical, electrical, thermal), in addition to the hydraulic forces, resulting in the so-called coupled flows. Fluid flow caused by driving forces different than hydraulic gradients is referred to as osmosis. Chemical osmosis, the water flow induced by a chemical gradient across a semi-permeable membrane, can generate pressure increase. The question thus arises if there is a risk to create high pore pressures that could damage the near-field of medium-level waste (MLW) galleries, if osmotically driven water flows towards the galleries are produced by the release of large amounts of NaNO 3 (750 t) in the formation. To what extent a low-permeability clay formation such as the Boom Clay acts as an osmotic membrane is thus a key issue to assess the relevance of osmosis phenomena for the disposal of medium-level waste. An in situ osmosis experiment has been conducted at the H ADES underground research laboratory to determine the osmotic efficiency of Boom Clay at the field scale. A recently developed chemical osmosis flow continuum model has been used to design the osmosis experiment, and to interpret the water pressure measurements. Experimental data could be reproduced quite accurately by the model, and the inferred parameter values are consistent with independent determinations for Boom Clay. A rapid water pressure increase (but limited to about a 2 m water column) was observed after 12 h in the filter containing the more saline water. Then, the osmotically induced water pressure slowly decays on several months. So, the experimental results obtained in situ confirm the occurrence of non-hydraulic flow phenomena (chemical osmosis) in a low

  4. Carbon Dioxide Nucleation as a Novel Cleaning Method for Sodium Alginate Fouling Removal from Reverse Osmosis Membranes desalination

    KAUST Repository

    Alnajjar, Heba

    2017-05-01

    The use of Reverse osmosis (RO) membranes have been significantly increasing in water desalination, and the main operational obstacle in RO desalination plants is membrane fouling. Among other solutes, dissolved biopolymers, such as polysaccharides can lead to severe membrane fouling especially with the addition of calcium ions because of the complexation formation between the surface of membrane and foulants materials. However, this complexation can also take place in the feed bulk, resulting in foulants aggregates formation. Although there are some physical techniques that can maintain the membrane performance without reducing its lifetime, only chemical cleanings are still commonly used in RO plants. In this study, a novel cleaning method is proposed to restore the membrane performance by removing the deposited foulants without reducing the membrane lifetime. The cleaning method is based on using water saturated with dissolved CO2 gas, and its principle is based on producing spontaneous CO2 bubbles due to local pressure difference leading to nucleation of bubbles throughout the membrane surface, especially at nucleation sites, which improve the cleaning efficiency. Alginic acid sodium salt was used as a model of polysaccharides foulants in presence of different concentrations of NaCl and calcium ions aiming to enhance membrane fouling, and then CO2 cleaning solution efficiency, in terms flux recovery (FR), was tested under different operating conditions and compared to other cleaning methods. Average FR of 20%±3, 25%±3 and 80%±3 for MilliQ water, a cleaning solution at pH4, and CO2 solution at 6 bar, 0.17 m/s, and 23 ̊C ±0.2 for 6 minutes were obtained, respectively. The efficiency of this novel cleaning method was also compared to direct osmosis overnight, and the average flux was comparable (about 60%±3), though that the cleaning time was significantly different. Various calcium concentrations (0-10 mM) were added in the alginate solution to study the

  5. Development of silica RO membranes

    International Nuclear Information System (INIS)

    Ikeda, Ayumi; Kawamoto, Takashi; Matsuyama, Emi; Utsumi, Keisuke; Nomura, Mikihiro; Sugimoto, Masaki; Yoshikawa, Masato

    2012-01-01

    Silica based membranes have been developed by using a counter diffusion CVD method. Effects of alkyl groups in the silica precursors and deposition temperatures had investigated in order to control pore sizes of the silica membranes. In this study, this type of a silica membrane was applied for RO separation. Effects of silica sources, deposition temperatures and post treatments had been investigated. Tetramethoxysilane (TMOS), Ethyltrimethoxysilane (ETMOS) and Phenyltrimethoxysilane (PhTMOS) were used as silica precursors. A counter diffusion CVD method was carried out for 90 min at 270 - 600degC on γ-alumina capillary substrates (effective length: 50 mm, φ: 4 nm: NOK Co.). O 3 or O 2 was introduced into the inside of the substrate at the O 2 rate of 0.2 L min -1 . Ion beam irradiation was carried out for a post treatment using Os at 490 MeV for 1.0 x 10 10 ions cm -2 or 3.0 x 10 10 ions cm -2 . Single gas permeance was measured by using H 2 , N 2 and SF 6 . RO tests were employed at 3.0 or 5.4 MPa for 100 mg L -1 of feed NaCl solution. First, effects of the silica sources were investigated. The total fluxes increased by increasing N 2 permeance through the silica membrane deposited by ETMOS. The maximum NaCl rejection was 28.2% at 12.2 kg m -2 h -1 of the total flux through the membrane deposited at 270degC. N 2 permeance was 9.6 x 10 -9 mol m -2 s -1 Pa -1 . While, total fluxes through the membrane deposited by using PhTMOS were smaller than those through the ETMOS membranes. The phenyl groups for the PhTMOS membrane must be important for the hydrophobic properties through the membrane. Next, effects of ion beam irradiation were tested for the TMOS membranes. Water is difficult to permeate through the TMOS membranes due to the low N 2 permeance through the membrane (3.1 x 10 -11 mol m -2 s -1 Pa -1 ). N 2 permeance increased to 7.3 x 10 -9 mol m -2 s -1 Pa -1 by the irradiation. Irradiation amounts had little effects on N 2 permeance. However, NaCl rejections

  6. Pressure Retarded Osmosis and Forward Osmosis Membranes: Materials and Methods

    Directory of Open Access Journals (Sweden)

    May-Britt Hägg

    2013-03-01

    Full Text Available In the past four decades, membrane development has occurred based on the demand in pressure driven processes. However, in the last decade, the interest in osmotically driven processes, such as forward osmosis (FO and pressure retarded osmosis (PRO, has increased. The preparation of customized membranes is essential for the development of these technologies. Recently, several very promising membrane preparation methods for FO/PRO applications have emerged. Preparation of thin film composite (TFC membranes with a customized polysulfone (PSf support, electorspun support, TFC membranes on hydrophilic support and hollow fiber membranes have been reported for FO/PRO applications. These novel methods allow the use of other materials than the traditional asymmetric cellulose acetate (CA membranes and TFC polyamide/polysulfone membranes. This review provides an outline of the membrane requirements for FO/PRO and the new methods and materials in membrane preparation.

  7. Experiences with a new technology of the water treatment at the reverse osmosis plant in the power station Schkopau; Betriebserfahrungen mit einer neuen Art der Wasserbehandlung an der Umkehrosmose-Anlage im Kraftwerk Schkopau

    Energy Technology Data Exchange (ETDEWEB)

    Geissler, K.P. [E.ON Kraftwerke, Schkopau (Germany); Nebauer, G.; Schallert, B. [E.ON Engineering, Gelsenkirchen (Germany); Koerner, J.; Koppe, J. [MOL Katalysatorentechnik GmbH, Schkopau (Germany)

    2003-07-01

    Similar to any river, the water of the river Saale shows strong fluctuations in the composition as a result of the local rain events and the climatic conditions. In the year 1992, when the planning started for the power station building the fluctuations of filtered substances, the acid capacity, the organic load of the water and the colony forming unities as a summary recording of bacteria etc. were not striking in comparison with former years. With the complete processing technique upstream of the reverse osmosis plant it became almost quantitatively to remove and to tie bacteria and higher microbiology and to eliminate diluted organic components (DOC), feast substances, and to reduce the carbonate hardness. The company MOL Katalysatortechnik GmbH offered power station operators already in 1999 a method with which biological growth can be limited in cooling circuits. (orig.) [German] Der Ueberschuss von Desinfektionsmitteln wie Chlor, Chlorbleichlauge oder Chlordioxid muss zwingend vor der UO-Anlage durch Zugabe von Reduktionsmitteln beseitigt sein, weil die UO-Membranen auf Polyamidbasis durch Oxidationsvorgaenge selbst nach kurzer Einwirkung Leistungsabnahmen aufweisen. Als Nachteil dieser Vorgehensweise bestehen bereits hinter der Dosierstelle des Reduktionsmittels, d.h. am Kerzenfilter und auch an der UO-Anlage, Bedingungen, die biologisches Wachstum kaum einschraenken und deshalb in hohem Masse zeitaufwaendige Reinigungsvorgaenge erfordern. (orig.)

  8. Osmosis process for leachate treatment in industrial platform: Economic and performances evaluations to zero liquid discharge.

    Science.gov (United States)

    Cingolani, Diego; Eusebi, Anna Laura; Battistoni, Paolo

    2017-12-01

    The industrial processes require large quantities of water. The presence of discharges results not only in significant environmental impact but implies wastage of water resources. This problem could be solved treating and reusing the produced wastewaters and applying the new zero liquid discharge approach. This paper discusses the design and the performances of reverse osmosis membranes for the upgrading of full scale platform for industrial liquid wastes. The final effluent from the ultrafiltration unit of the full scale plant was monitored to design the reverse osmosis unit. Previous modelling phase was used to evaluate the specific ordinary and maintenance costs and the final effluent quality (2.7 €/m 3 ). The system was designed in triple stages at different operative pressures. The economic feasibility and the payback period of the technology at different percentages of produced permeate were determined. The recovery of 90% was identified as profitable for the reverse osmosis application. One experimental pilot plant applying the reverse osmosis was used to test the final effluent. Moreover, the same flow was treated with second pilot system based on the forward osmosis process. The final efficiencies were compared. Removals higher than 95% using the reverse system were obtained for the main macropollutants and ions. No sustainable applicability of the forward osmosis was determined. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. High performance thin-film composite forward osmosis membrane.

    Science.gov (United States)

    Yip, Ngai Yin; Tiraferri, Alberto; Phillip, William A; Schiffman, Jessica D; Elimelech, Menachem

    2010-05-15

    Recent studies show that osmotically driven membrane processes may be a viable technology for desalination, water and wastewater treatment, and power generation. However, the absence of a membrane designed for such processes is a significant obstacle hindering further advancements of this technology. This work presents the development of a high performance thin-film composite membrane for forward osmosis applications. The membrane consists of a selective polyamide active layer formed by interfacial polymerization on top of a polysulfone support layer fabricated by phase separation onto a thin (40 mum) polyester nonwoven fabric. By careful selection of the polysulfone casting solution (i.e., polymer concentration and solvent composition) and tailoring the casting process, we produced a support layer with a mix of finger-like and sponge-like morphologies that give significantly enhanced membrane performance. The structure and performance of the new thin-film composite forward osmosis membrane are compared with those of commercial membranes. Using a 1.5 M NaCl draw solution and a pure water feed, the fabricated membranes produced water fluxes exceeding 18 L m(2-)h(-1), while consistently maintaining observed salt rejection greater than 97%. The high water flux of the fabricated thin-film composite forward osmosis membranes was directly related to the thickness, porosity, tortuosity, and pore structure of the polysulfone support layer. Furthermore, membrane performance did not degrade after prolonged exposure to an ammonium bicarbonate draw solution.

  10. High Performance Thin-Film Composite Forward Osmosis Membrane

    KAUST Repository

    Yip, Ngai Yin

    2010-05-15

    Recent studies show that osmotically driven membrane processes may be a viable technology for desalination, water and wastewater treatment, and power generation. However, the absence of a membrane designed for such processes is a significant obstacle hindering further advancements of this technology. This work presents the development of a high performance thin-film composite membrane for forward osmosis applications. The membrane consists of a selective polyamide active layer formed by interfacial polymerization on top of a polysulfone support layer fabricated by phase separation onto a thin (40 μm) polyester nonwoven fabric. By careful selection of the polysulfone casting solution (i.e., polymer concentration and solvent composition) and tailoring the casting process, we produced a support layer with a mix of finger-like and sponge-like morphologies that give significantly enhanced membrane performance. The structure and performance of the new thin-film composite forward osmosis membrane are compared with those of commercial membranes. Using a 1.5 M NaCl draw solution and a pure water feed, the fabricated membranes produced water fluxes exceeding 18 L m2-h-1, while consistently maintaining observed salt rejection greater than 97%. The high water flux of the fabricated thin-film composite forward osmosis membranes was directly related to the thickness, porosity, tortuosity, and pore structure of the polysulfone support layer. Furthermore, membrane performance did not degrade after prolonged exposure to an ammonium bicarbonate draw solution. © 2010 American Chemical Society.

  11. Find selv fred og ro

    DEFF Research Database (Denmark)

    Juelskjær, Malou

    2010-01-01

    I klasseværelset er det lærerens ansvar at skabe ro. Men i de nye skolebygninger er det den enkelte elevs ansvar at finde frem til fredfyldte steder.......I klasseværelset er det lærerens ansvar at skabe ro. Men i de nye skolebygninger er det den enkelte elevs ansvar at finde frem til fredfyldte steder....

  12. Effects of feed solution chemistry on low pressure reverse osmosis filtration of cesium and strontium

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Shiyuan, E-mail: dingshiyuan@bnu.edu.cn [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875 (China); Yang, Yu, E-mail: yangyu@bnu.edu.cn [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875 (China); Huang, Haiou, E-mail: huanghaiou@bnu.edu.cn [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875 (China); Liu, Hengchen, E-mail: 799599501@qq.com [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875 (China); Hou, Li-an, E-mail: houlian678@hotmail.com [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875 (China); Xi’an High-Tech Institute, No. 2, Tongxin Street, Baqiao District, Xi’an 710025 (China)

    2015-08-30

    Highlights: • A low pressure spiral wound RO membrane can reject Cs and Sr efficiently. • The rejection of Cs and Sr is dependent on feed pH and co-existing ions. • Donnan exclusion and electrostatic interaction govern the rejection of Cs and Sr. • The differences of filtration mechanism were influenced by the size of ions. • Sr could strengthen the irreversible membrane fouling resistance with HA. - Abstract: The objective of this study was to identify the removal mechanisms of radionuclides by reverse osmosis (RO) membranes under conditions relevant to full-scale water treatment. For this purpose, the effects of feed solution chemistry on the removal of Cs and Sr by a low pressure RO system was investigated by systematically varying membrane surface charge, ionic composition, and organic matter concentrations. The results showed that the effects of solution chemistry on the filtration of Cs and Sr were related to their hydrated ionic radius, resulting in the predominance of the Donnan’s effect and electrostatic interactions, respectively. Consequently, the rejection of Cs increased more pronouncedly than Sr with the increases of feed concentration. Due to the Donnan’s effect, different anions decreased the rejection of Cs to different extents in accordance to the order of anions’ radii as SO{sub 4}{sup 2−} > Cl{sup −} > NO{sub 3}{sup −} > F{sup −}. The variations in Sr rejection were influenced by the electrostatic interactions between Sr{sup 2+} and the membrane. In addition, humic acid (HA) lowered the rejection of Cs and caused significant membrane flux decline, but did not change the rejection of Sr. Sr also aggravated HA fouling of the membrane.

  13. Reverse osmosis seawater test facility on board NS Otto Hahn

    International Nuclear Information System (INIS)

    Boeddeker, K.W.; Hilgendorff, W.; Kaschemekat, J.

    1977-01-01

    To evaluate the performance of reverse osmosis membranes and prototype modules for the desalination of sea water under near technical conditions, a test station has been installed on board the nuclear research vessel NS Otto Hahn. A newly designed plate module with variable membrane area and favorable membrane exchange properties is being used as a test instrument for membranes and operating conditions. (orig./HK) [de

  14. Unlocking High-Salinity Desalination with Cascading Osmotically Mediated Reverse Osmosis: Energy and Operating Pressure Analysis.

    Science.gov (United States)

    Chen, Xi; Yip, Ngai Yin

    2018-02-20

    Current practice of using thermally driven methods to treat hypersaline brines is highly energy-intensive and costly. While conventional reverse osmosis (RO) is the most efficient desalination technique, it is confined to purifying seawater and lower salinity sources. Hydraulic pressure restrictions and elevated energy demand render RO unsuitable for high-salinity streams. Here, we propose an innovative cascading osmotically mediated reverse osmosis (COMRO) technology to overcome the limitations of conventional RO. The innovation utilizes the novel design of bilateral countercurrent reverse osmosis stages to depress the hydraulic pressure needed by lessening the osmotic pressure difference across the membrane, and simultaneously achieve energy savings. Instead of the 137 bar required by conventional RO to desalinate 70 000 ppm TDS hypersaline feed, the highest operating pressure in COMRO is only 68.3 bar (-50%). Furthermore, up to ≈17% energy saving is attained by COMRO (3.16 kWh/m 3 , compared to 3.79 kWh/m 3 with conventional RO). When COMRO is employed to boost the recovery of seawater desalination to 70% from the typical 35-50%, energy savings of up to ≈33% is achieved (2.11 kWh/m 3 , compared to 3.16 kWh/m 3 with conventional RO). Again, COMRO can operate at a moderate hydraulic pressure of 80 bar (25% lower than 113 bar of conventional RO). This study highlights the encouraging potential of energy-efficient COMRO to access unprecedented high recovery rates and treat hypersaline brines at moderate hydraulic pressures, thus extending the capabilities of membrane-based technologies for high-salinity desalination.

  15. Dynamics of microbial communities in an integrated ultrafiltration–reverse osmosis desalination pilot plant located at the Arabian Gulf

    KAUST Repository

    Hong, Pei-Ying

    2015-08-27

    This study demonstrated the use of high-throughput sequencing to assess the efficacy of an integrated ultrafiltration (UF)–reverse osmosis (RO) desalination pilot plant located at the Arabian Gulf, and to identify potential microbial-associated problems that may arise in this plant. When integrated into the desalination treatment system, the UF membranes were able to serve as a good pretreatment strategy to delay RO fouling by achieving up to 1.96-log removal of cells from the seawater. Consequently, the differential pressure of the RO membrane remained around 1 bar for the entire six-month study, suggesting no significant biofouling performance issue identified for this RO system. Examples of microbial populations effectively removed by the UF membranes from the feed waters included Nitrosoarchaeum limnia and phototrophic eukaryotes. Microbial-associated problems observed in this pilot plant included the presence of Pseudomonas spp. in coexistence with Desulfovibrio spp. These two bacterial populations can reduce sulfate and produce hydrogen sulfide, which would in turn cause corrosion problems or compromise membrane integrities. Chemical-enhanced backwashing (CEB) can be used as an effective strategy to minimize the associated microbial problems by removing bacterial populations including sulfate reducers from the UF membranes.

  16. Dynamics of microbial communities in an integrated ultrafiltration–reverse osmosis desalination pilot plant located at the Arabian Gulf

    KAUST Repository

    Hong, Pei-Ying; Moosa, Nasir; Mink, Justine

    2015-01-01

    This study demonstrated the use of high-throughput sequencing to assess the efficacy of an integrated ultrafiltration (UF)–reverse osmosis (RO) desalination pilot plant located at the Arabian Gulf, and to identify potential microbial-associated problems that may arise in this plant. When integrated into the desalination treatment system, the UF membranes were able to serve as a good pretreatment strategy to delay RO fouling by achieving up to 1.96-log removal of cells from the seawater. Consequently, the differential pressure of the RO membrane remained around 1 bar for the entire six-month study, suggesting no significant biofouling performance issue identified for this RO system. Examples of microbial populations effectively removed by the UF membranes from the feed waters included Nitrosoarchaeum limnia and phototrophic eukaryotes. Microbial-associated problems observed in this pilot plant included the presence of Pseudomonas spp. in coexistence with Desulfovibrio spp. These two bacterial populations can reduce sulfate and produce hydrogen sulfide, which would in turn cause corrosion problems or compromise membrane integrities. Chemical-enhanced backwashing (CEB) can be used as an effective strategy to minimize the associated microbial problems by removing bacterial populations including sulfate reducers from the UF membranes.

  17. Study of the effectiveness of polyamide reverse osmosis membranes in the recovery of Cr(III) in tanning. Estudio sobre la efectividad de las membranas de osmosis inversa de poliamida en la recuperacion de Cr(III) en curticion

    Energy Technology Data Exchange (ETDEWEB)

    Galan, M.; Gonzalez, C.; Llorens, J.; Mans, C. (Barcelona Univ., Tarragona (Spain). Dept. d' Enginyeria Quimica i Bioqumica)

    1992-12-01

    Laboratory experiments on reverse osmosis using water containing Cr2(SO4)3 and a Film Tech Corporation TW30-2514 membrane are described. The type of cell employed allowed the membrane's rejection of Cr(III) to be measured with a high degree of accuracy. Tests were carried out varying the Cr concentration, the pressure and the temperature. The results obtained have implications regarding the suitability of reverse osmosis in recovering Cr from tanning waste water. (Author)

  18. Reverse osmosis and its use at the nuclear power plants. Purification of primary circuit coolant by the means of reverse osmosis

    International Nuclear Information System (INIS)

    Kus, Pavel; Vonkova, Katerina; Kunesova, Katerina; Bartova, Sarka; Skala, Martin; Moucha, Tomáš

    2014-01-01

    This contribution is focused on the use of membrane technologies (e.g. reverse osmosis) for the primary coolant purification at the nuclear power plants. Currently, boric acid present in the primary coolant is preconcentrated at the evaporators, but their operation is very inefficient and expensive. Therefore, reverse osmosis was proposed as one of promising methods possibly replacing evaporators. The aim of the purification process is to achieve boric acid solution of a defined concentration (40 g/l) in the retentate stream in order to recycle it and reuse it in the primary circuit. Additionally, permeate flow should consist solely of pure water. To study the efficiency of several reverse osmosis modulus in the boric acid removal form the water solutions, experimental apparatus was constructed in our laboratory. It consists of the solution reservoir, pump and reverse osmosis modulus. The arrangement of experiments was batch and the retentate flow was refluxed to the feed solution. Several modulus of commercial reverse osmosis membranes were tested. The feed solution contained various concentrations of H 3 BO 3 , KOH, LiOH and NH 3 in order to simulate real primary coolant composition. Based on the experimental results, mathematical model was developed in order to optimize experimental conditions for the best results in primary coolant purification and boric acid preconcentration. (author)

  19. The impact of chemical cleaning on separation efficiency and properties of reverse osmosis membrane

    KAUST Repository

    Baatiyyah, Hani

    2018-04-01

    One of most major concerns from both cost-effective and technical point of view in membrane process industry is membrane cleaning. The aim of the project was to investigate the variations in membrane surface properties and separation efficiency of reverse osmosis membrane. Compativtive analysis have to be performed on four RO membrane before and after exposing the virgin membrane into chemical cleaning to identify and analysis the impact of the chemical cleaning on the performance of RO membrane. Commerical chemical cleaning used in this project were caustic and acidic cleaning agent. The project’s aim is the investigation of simulation software’s precision for the four membranes performance projection at different conditions of the feed water. The assessment of the membranes performance was done in the Innovation Cluster at pilot plant that was industrial in size. The main commercial elements used were the thin-film composite membranes with a spiral-wound of 8-inch polyamide. Ultrafiltration (UF) and seawater RO membrane pretreatment process was done for the red sea sourced feed water. A pressure vessel dimensioned at 8-inch was operated in conjunction with an individual element at 8 -20 m3/hr feed flow rate, with an 8 to 12 % recovery and an average 35,000-42,000 mg/L of total dissolved solids (TDS) composition for the feed water. To achieve the project’s aim in assessing the membranes, three phase experimental stages were completed. The membranes performance was assessed in terms of their water flux, salt rejection, boron rejection, bicarbonate rejection and permeate quality. In addition, the membrane surfaces were characterized after exposing the fresh membranes with a chemical cleaning reagent. The experimental results showed an increase in both permeate flow and salt passage for all studied elements. The changes in the membranes performance were systematically explained based on the changes in the charge density and chemical structure of the membranes

  20. Performance of electrodialysis reversal and reverse osmosis for reclaiming wastewater from high-tech industrial parks in Taiwan: A pilot-scale study.

    Science.gov (United States)

    Yen, Feng-Chi; You, Sheng-Jie; Chang, Tien-Chin

    2017-02-01

    Wastewater reclamation is considered an absolute necessity in Taiwan, as numerous industrial parks experience water shortage. However, the water quality of secondary treated effluents from sewage treatment plants generally does not meet the requirements of industrial water use because of the high inorganic constituents. This paper reports experimental data from a pilot-plant study of two treatment processes-(i) fiber filtration (FF)-ultrafiltration (UF)-reverse osmosis (RO) and (ii) sand filtration (SF)-electrodialysis reversal (EDR)-for treating industrial high conductivity effluents from the Xianxi wastewater treatment plant in Taiwan. The results demonstrated that FF-UF was excellent for turbidity removal and it was a suitable pretreatment process for RO. The influence of two membrane materials on the operating characteristics and process stability of the UF process was determined. The treatment performance of FF-UF-RO was higher than that of SF-EDR with an average desalination rate of 97%, a permeate conductivity of 272.7 ± 32.0, turbidity of 0.183 ± 0.02 NTU and a chemical oxigen demand of <4.5 mg/L. The cost analysis for both processes in a water reclamation plant of 4000 m 3 /d capacity revealed that using FF-UF-RO had a lower treatment cost than using SF-EDR, which required activated carbon filtration as a post treatment process. On the basis of the results in this study, the FF-UF-RO system is recommended as a potential process for additional applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. The use of microbial and chemical analyses to characterize the variations in fouling profile of seawater reverse osmosis (SWRO) membrane

    KAUST Repository

    Manes, Carmem Lara De O

    2013-01-01

    Biofouling of reverse osmosis (RO) membranes is one of the most common problems in desalinations plants reducing the efficiency of the water production process. The characterization of bacterial community composition from fouling layers as well as detailed analysis of surrounding chemical environment might reveal process specific bacterial groups/species that are involved in RO biofouling. In this study, advanced organics analytic methods (elemental analysis, FTIR, and ICP-OES) were combined with high-throughput 16S rRNA (pyro) sequencing to assess in parallel, the chemical properties and the active microbial community composition of SWRO membranes from a pilot desalination plant (MFT, Tarragona) in February 2011 and July 2011. Prefiltered ultrafiltration. waters fed SWRO membranes during third and fifth month of operation, respectively. SWRO samples were taken from three modules at different positions (first, fourth, and sixth) in order to investigate the spatial changes in fouling layers\\' chemical and microbiological composition. The overall assessment of chemical parameters revealed that fouling layers were mainly composed by bio and organic material (proteins and lipids). Ca and Fe were found to be the most abundant elements having an increasing concentration gradient according to the module position. Bacterial community composition of SWRO membranes is mostly represented by the Gammaproteobacteria class with interesting differences in genera/species spatial and temporal distribution. This preliminary result suggests that pretreatments and/or operational conditions might have selected different bacterial groups more adapted to colonize SWRO membranes. © 2013 Desalination Publications.

  2. Anomalous osmosis resulting from preferential absorption

    NARCIS (Netherlands)

    Staverman, A.J.; Kruissink, C.A.; Pals, D.T.F.

    1965-01-01

    An explanation of the anomalous osmosis described in the preceding paper is given in terms of friction coefficients in the glass membrane. It is shown that anomalous osmosis may be expected when the friction coefficients are constant and positive provided that the membrane absorbs solute strongly

  3. Technical feasibility of using gallery intakes for seawater RO facilities, northern Red Sea coast of Saudi Arabia: The King Abdullah Economic City site

    KAUST Repository

    Dehwah, Abdullah

    2013-02-13

    The Kingdom of Saudi Arabia is dependent on desalination of seawater to provide new water supplies for the future. Desalination is expensive and it is very important to reduce the cost and lower the energy consumption. Most seawater reverse osmosis facilities use open-ocean intakes, which require extensive pretreatment processes to remove particulate and biological materials that cause operating problems such as membrane fouling or shutdown during algal blooms. Subsurface systems, using the concept of riverbank filtration, can be used as intakes. These systems include wells of various designs and galleries that provide natural filtration and biological treatment to improve the quality of feed water before it enters the desalination plant. This reduces operating cost, lowers chemical and energy consumption, and reduces environmental impacts. Technical feasibility of gallery-type intakes, beach and seabed types, for use as intakes to seawater reverse osmosis (RO) facilities was evaluated along the northern Red Sea shoreline of Saudi Arabia. The geological characteristics of the offshore ocean bottom were found to be favorable for the development of seabed gallery systems, but the shoreline geology was not adequate for the development of beach gallery intakes. One of the potentially favorable sites for a seabed gallery system was located in the nearshore area at King Abdullah Economic City (KAEC). Detailed investigation of the site hydrology (tides and wave action), sediment grain size characteristics, and sediment hydraulic conductivity, and access for construction were assessed. It was determined that seabed gallery development is favorable at the site. Based on the seawater that has a salinity of about 41,000 mg/L and a conversion rate of 40%, a conservatively designed gallery cell with dimensions of 100 by 50 m would produce about 25,000 m3/day of filtered seawater and seven cells (6 primary and 1 standby) could support a 60,000 m3/day (permeate) seawater RO plant

  4. Forward osmosis biomimetic membranes in industrial and environmental applications

    DEFF Research Database (Denmark)

    Madsen, Henrik Tækker; Søgaard, Erik Gydesen; Bajraktari, Niada

    Membrane processes have in recent years found increasing uses in several sectors where separation of one or more components from a solvent, typically water, is required. The most widespread types of membranes are polymeric and pressure driven, but the high pressures that are required results...... consumption and lead to much more stable operations, but is currently limited by the availability of suitable membranes. However, by introducing aquaporin protein channels into a polymeric membrane to make a biomimetic membrane, the vision of both high flux and separation efficiency may be achieved......) a single use filtration module containing a sample reservoir and a biomimetic aquaporin based forward osmosis membrane. 2) a multi-use desktop forward osmosis system containing draw solution mixing, and monitoring devices. The sample is placed in the single use module and the module is then mounted...

  5. Summary of the ultrafiltration, reverse osmosis, and adsorbents project

    International Nuclear Information System (INIS)

    Colvin, C.M.; Roberts, R.C.; Williams, M.K.

    1983-01-01

    The design for a medium-size (40 gal/min) ultrafiltration (UF) membrane unit includes a schematic diagram, capital and operating costs, a list and discussion of the radioisotopes tested and the results achieved, operating parameters, and characteristics of the available membrane configurations. The plant design for a reverse osmosis (RO) membrane unit includes a conceptual diagram, specifications for a RO unit producing 40 gal/min of permeated product, a list of radioisotopes tested on RO units and the rejections achieved, a discussion of the principal of RO, a discussion of the upper limits of cation and anion concentrations (there are no lower limits), a discussion of membrane configurations and porosities, a discussion of factors affecting membranes, a section on calculating the membrane area needed for a particular application, and capital and operating cost calculations. The design for an ion-exchange pilot plant includes a schematic diagram; flow, resin, and column specifications; impurity limits; and operating and capital costs. A short theoretical discussion and process description are also included. The design retains flexibility so that application to a specific stream can be determined

  6. Fouling of Seawater Reverse Osmosis (SWRO) Membrane: Chemical and Microbiological Characterization

    KAUST Repository

    Khan, Muhammad T.

    2013-12-01

    In spite of abundant water resources, world is suffering from the scarcity of usable water. Seawater Reverse Osmosis (SWRO) desalination technology using polymeric membranes has been recognized as a key solution to water scarcity problem. However, economic sustainability of this advanced technology is adversely impacted by the membrane fouling problem. Fouling of RO membranes is a highly studied phenomenon. However, literature is found to be lacking a detailed study on kinetic and dynamic aspects of SWRO membrane fouling. The factors that impact the fouling dynamics, i.e., pretreatment and water quality were also not adequately studied at full–scale of operation. Our experimental protocol was designed to systematically explore these fouling aspects with the objective to improve the understanding of SWRO membrane fouling mechanisms. An approach with multiple analytical techniques was developed for fouling characterization. In addition to the fouling layer characterization, feed water quality was also analysed to assess its fouling potential. Study of SWRO membrane fouling dynamics and kinetics revealed variations in relative abundance of chemical and microbial constituents of the fouling layer, over operating time. Aromatic substances, most likely humic–like substances, were observed at relatively high abundance in the initial fouling layer, followed by progressive increase in relative abundances of proteins and polysaccharides. Microbial population grown on all membranes was dominated by specific groups/species belonging to different classes of Proteobacteria phylum; however, similar to abiotic foulant, their relative abundance also changed with the biofilm age and with the position of membrane element in RO vessel. Our results demonstrated that source water quality can significantly impact the RO membrane fouling scenarios. Moreover, the major role of chlorination in the SWRO membrane fouling was highlighted. It was found that intermittent mode of chlorination

  7. Double-Skinned Forward Osmosis Membranes for Reducing Internal Concentration Polarization within the Porous Sublayer

    KAUST Repository

    Wang, Kai Yu

    2010-05-19

    A scheme to fabricate forward osmosis membranes comprising a highly porous sublayer sandwiched between two selective skin layers via phase inversion was proposed. One severe deficiency of existing composite and asymmetric membranes used in forward osmosis is the presence of unfavorable internal concentration polarization within the porous support layer that hinders both (i) separation (salt flux) and (ii) the performance (water flux). The double skin layers of the tailored membrane may mitigate the internal concentration polarization by preventing the salt and other solutes in the draw solution from penetrating into the membrane porous support. The prototype double-skinned cellulose acetate membrane displayed a water flux of 48.2 L·m-2·h -1 and lower reverse salt transport of 6.5 g·m -2·h-1 using 5.0 M MgCl2 as the draw solution in a forward osmosis process performed at 22 °C. This can be attributed to the effective salt rejection by the double skin layers and the low water transport resistance within the porous support layer. The prospects of utilizing the double-selective layer membranes may have potential application in forward osmosis for desalination. This study may help pave the way to improve the membrane design for the forward osmosis process. © 2010 American Chemical Society.

  8. Influences of mechanical pretreatment on the non-biological treatment of municipal wastewater by forward osmosis.

    Science.gov (United States)

    Hey, Tobias; Zarebska, Agata; Bajraktari, Niada; Vogel, Jörg; Hélix-Nielsen, Claus; la Cour Jansen, Jes; Jönsson, Karin

    2017-09-01

    Municipal wastewater treatment involves mechanical, biological and chemical treatment steps for protecting the environment from adverse effects. The biological treatment step consumes the most energy and can create greenhouse gases. This study investigates municipal wastewater treatment without the biological treatment step, including the effects of different pretreatment configurations, for example, direct membrane filtration before forward osmosis. Forward osmosis was tested using raw wastewater and wastewater subjected to different types of mechanical pretreatment, for example, microsieving and microfiltration permeation, as a potential technology for municipal wastewater treatment. Forward osmosis was performed using Aquaporin Inside™ and Hydration Technologies Inc. (HTI) membranes with NaCl as the draw solution. Both types of forward osmosis membranes were tested in parallel for the different types of pretreated feed and evaluated in terms of water flux and solute rejection, that is, biochemical oxygen demand (BOD 7 ) and total and soluble phosphorus contents. The Aquaporin and HTI membranes achieved a stable water flux with rejection rates of more than 96% for BOD 7 and total and soluble phosphorus, regardless of the type of mechanical pretreated wastewater considered. This result indicates that forward osmosis membranes can tolerate exposure to municipal waste water and that the permeate can fulfil the Swedish discharge limits.

  9. Energy consumption for sugar manufacturing. Part I: Evaporation versus reverse osmosis

    International Nuclear Information System (INIS)

    Madaeni, S.S.; Zereshki, S.

    2010-01-01

    Removing water from various feeds is usually carried out using evaporation process especially in food industry. Due to the high latent heat of water, this unit operation results in consumption of unacceptable amount of energy. Finding low energy consuming processes which could be replaced with this process is still a challenge. The processes with no phase inversion may be considered for concentration purposes with reasonable energy consumption in comparison with the other various separation procedures. Reverse osmosis and most of the other membrane technologies are separation techniques without any change in the phase and therefore consume low amount of energy. Concentrating the sugar thin juice in the classical sugar manufacturing procedure is carried out using conventional evaporation. Reverse osmosis membranes may be used as a pre-concentration step to partially separate water from the sugar thin juice in combination with this part of the plant. Final concentration and thick juice preparation for crystallization may be carried out in the evaporation unit. In this study, membranes were employed for sugar thin juice concentration using a two-stage reverse osmosis process in two different arrangements. The energy consumption was calculated and compared for conventional evaporation versus reverse osmosis combined with evaporation. The results indicate that the employment of reverse osmosis membranes for concentrating the sugar thin juice leads to sensibly lower energy requirements. Furthermore, there is no thermal loss of sugar in the membrane process.

  10. Double-Skinned Forward Osmosis Membranes for Reducing Internal Concentration Polarization within the Porous Sublayer

    KAUST Repository

    Wang, Kai Yu; Ong, Rui Chin; Chung, Tai-Shung

    2010-01-01

    A scheme to fabricate forward osmosis membranes comprising a highly porous sublayer sandwiched between two selective skin layers via phase inversion was proposed. One severe deficiency of existing composite and asymmetric membranes used in forward osmosis is the presence of unfavorable internal concentration polarization within the porous support layer that hinders both (i) separation (salt flux) and (ii) the performance (water flux). The double skin layers of the tailored membrane may mitigate the internal concentration polarization by preventing the salt and other solutes in the draw solution from penetrating into the membrane porous support. The prototype double-skinned cellulose acetate membrane displayed a water flux of 48.2 L·m-2·h -1 and lower reverse salt transport of 6.5 g·m -2·h-1 using 5.0 M MgCl2 as the draw solution in a forward osmosis process performed at 22 °C. This can be attributed to the effective salt rejection by the double skin layers and the low water transport resistance within the porous support layer. The prospects of utilizing the double-selective layer membranes may have potential application in forward osmosis for desalination. This study may help pave the way to improve the membrane design for the forward osmosis process. © 2010 American Chemical Society.

  11. High solute rejecting membranes for reverse osmosis: Polyetheramide hydrazide

    International Nuclear Information System (INIS)

    Bindal, R.C.; Ramachandhran, V.; Misra, B.M.; Ramani, M.P.S.

    1991-01-01

    Synthesis of benzhydrazide polymers and determination of reverse osmosis properties of their membranes were reported earlier. Their performance was not adequate for seawater desalination or for high radioactive decontamination factors (DF). The same hydrazide polymers modified by incorporation of additional monomers with ether linkages were synthesized by low temperature polycondensation of freshly prepared m-amino benzhydrazide, p-amino benzhydrazide, and 4,4'-diamino diphenyl ether, with isophthaloyl chloride and terephthaloyl chloride in dimethyl acetamide solvent. A series of film-forming polymers prepared by altering the molar ratios of the reacting monomers were characterized in terms of percent moisture regain, inherent viscosity, solubility parameters, and interfacial sorption characteristics. Asymmetric membranes prepared from these polymer samples were characterized in terms of the pure water permeability constant and the solute transport parameter, and were tested for their reverse osmosis performance. An optimum mole ratio of reaching monomers has been identified for the synthesis of polymer and the resulting membrane offered the best performance for reverse osmosis (salt rejection as high as 99.4% for 3.5% sodium chloride solution). The incorporation of aromatic ether linkages in the polyamide benzhydrazide polymeric chains appears to alter the polar and nonpolar character of the bulk polymer, and also the membrane solution interface characteristics, resulting in enhanced solute separation. These membranes appear to be potential candidates for single-stage seawater desalination and also for a variety of industrial effluent treatment applications for significantly high DF radioactive effluent treatment

  12. Electrochemical oxidation of tramadol in low-salinity reverse osmosis concentrates using boron-doped diamond anodes.

    Science.gov (United States)

    Lütke Eversloh, Christian; Schulz, Manoj; Wagner, Manfred; Ternes, Thomas A

    2015-04-01

    The electrochemical treatment of low-salinity reverse osmosis (RO) concentrates was investigated using tramadol (100 μM) as a model substance for persistent organic contaminants. Galvanostatic degradation experiments using boron-doped diamond electrodes at different applied currents were conducted in RO concentrates as well as in ultra-pure water