Purification of Drinking Water from Fluorides by Reverse Osmosis

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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.

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.

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

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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.

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.

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

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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.

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.

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

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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.

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.

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.

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.

Concentration of pineapple juice by reverse osmosis: physicochemical characteristics and consumer acceptance

Directory of Open Access Journals (Sweden)

Daniel Simões Couto

2011-12-01

Full Text Available Reverse osmosis has been used for the concentration of fruit juices with promising considering the quality of the obtained products. The objective of this study was to concentrate single strength pineapple juice by reverse osmosis. The concentration was carried out with polyamide composite membranes in a 0.65 m² plate and frame module at 60 bar transmembrane pressure at 20 °C. The permeate flux was 17 L.hm-2. The total soluble solid content of the juice increased from 11 to 31 °Brix corresponding to a Volumetric Concentration Factor (VCF of 2.9. The concentration of soluble solids, total solids, and total acidity increased proportionally to FCV. The concentrated juice and three commercial concentrated pineapple juices were evaluated regarding preference and purchase intention by 79 pineapple juice consumers. The concentrated juice by reverse osmosis was the preferred among consumers. It can be concluded that this process may be considered an alternative to the pre-concentration of fruit juices.

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...

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

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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.

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.

Treatment of dairy effluent model solutions by nanofiltration and reverse osmosis

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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.

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.

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

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 containing either sodium chloride or sodium sulfate. Kinetic investigations revealed a significant influence of in-situ generated active chlorine besides direct anodic oxidation. Therefore, tramadol concentrations decreased more rapidly at elevated chloride content. Nevertheless, reduction of total organic carbon (TOC) was found to be comparatively low, demonstrating that transformation rather than mineralization was taking place. Early stage product formation could be attributed to both direct and indirect processes, including demethylation, hydroxylation, dehydration, oxidative aromatic ring cleavage and halogenation reactions. The latter led to various halogenated derivatives and resulted in AOX (adsorbable organic halogens) formation in the lower mg/L-range depending on the treatment conditions. Characterisation of transformation products (TPs) was achieved via MS(n) experiments and additional NMR measurements. Based on identification and quantification of the main TPs in different matrices and on additional potentiostatic electrolysis, a transformation pathway was proposed. Copyright © 2014 Elsevier Ltd. All rights reserved.

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...

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...

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.

[Influence of reverse osmosis concentrate on physicochemical parameters of Sini decoction material system and their relevance].

Science.gov (United States)

Jin, Tang-Hui; Zhang, Liu-Hong; Zhu, Hua-Xu; Guo, Li-Wei; Li, Bo; Lu, Ming-Ming

2014-04-01

By studying the process of reverse osmosis system for traditional Chinese medicine materials physicochemical parameters affecting the osmotic pressure of its relevance, new compound system reverse osmosis process design methods were explored. Three concentrations materials for high, middle and low were dubbed with Sini decoction as a model drug, and pretreated by 50 thousand relative molecular weight cut-off ultrafiltration membrane. The viscosity, turbidity, conductivity, salinity, TDS, pH value and osmotic pressure of each sample were determined after the reverse osmosis to study the physical and chemical parameters between their respective correlations with the osmotic pressure, and characterized by HPLC chromatograms showing changes before and after the main chemical composition of samples of reverse osmosis. Conductivity-osmotic pressure, salinity-osmotic pressure of the linear correlation coefficient, TDS-osmotic pressure between the three sets of parameters were 0.963 8, 0.932 7, 0.973 7, respectively. Reverse osmosis concentrate and its characteristic spectrum ultrafiltrate HPLC similarity were up to 0. 968 or more, except the low concentrations. There is a significant correlation between the three physicochemical parameters (conductivity, salinity, TDS) and osmotic pressure of each sample system, and there is also significant linear correlation between salinity, conductivity, TDS. The original chemical composition of Sini decoction material concentrate was completely remained after the process of reverse osmosis.

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

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.

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...

Predicting and measurement of pH of seawater reverse osmosis concentrates

KAUST Repository

Waly, Tarek; Kennedy, Maria Dolores; Witkamp, Geert-Jan; Amy, Gary L.; Schippers, Jan Cornelis

2011-01-01

The pH of seawater reverse osmosis plants (SWRO) is the most influential parameter in determining the degree of supersaturation of CaCO3 in the concentrate stream. For this, the results of pH measurements of the concentrate of a seawater reverse

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.

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

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

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

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...

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.¬

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.

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

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.

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.

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

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.

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.

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.

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

Changes in the components and biotoxicity of dissolved organic matter in a municipal wastewater reclamation reverse osmosis system.

Science.gov (United States)

Sun, Ying-Xue; Hu, Hong-Ying; Shi, Chun-Zhen; Yang, Zhe; Tang, Fang

2016-09-01

The characteristics of dissolved organic matter (DOM) and the biotoxicity of these components were investigated in a municipal wastewater reclamation reverse osmosis (mWRRO) system with a microfiltration (MF) pretreatment unit. The MF pretreatment step had little effect on the levels of dissolved organic carbon (DOC) in the secondary effluent, but the addition of chlorine before MF promoted the formation of organics with anti-estrogenic activity. The distribution of excitation emission matrix (EEM) fluorescence constituents exhibited obvious discrepancies between the secondary effluent and the reverse osmosis (RO) concentrate. Using size exclusion chromatography, DOM with low molecular weights of approximately 1.2 and 0.98 kDa was newly formed during the mWRRO. The normalized genotoxicity and anti-estrogenic activity of the RO concentrate were 32.1 ± 10.2 μg4-NQO/mgDOC and 0.36 ± 0.08 mgTAM/mgDOC, respectively, and these values were clearly higher than those of the secondary effluent and MF permeate. The florescence volume of Regions I and II in the EEM spectrum could be suggested as a surrogate for assessing the genotoxicity and anti-estrogenic activity of the RO concentrate.

Predicting and measurement of pH of seawater reverse osmosis concentrates

KAUST Repository

Waly, Tarek

2011-10-01

The pH of seawater reverse osmosis plants (SWRO) is the most influential parameter in determining the degree of supersaturation of CaCO3 in the concentrate stream. For this, the results of pH measurements of the concentrate of a seawater reverse osmosis pilot plant were compared with pH calculations based on the CO2-HCO3 --CO3 2- system equilibrium equations. Results were compared with two commercial software programs from membrane suppliers and also the software package Phreeqc. Results suggest that the real concentrate pH is lower than that of the feed and that none of the used programs was able to predict correctly real pH values. In addition, the effect of incorporating the acidity constant calculated for NaCl medium or seawater medium showed a great influence on the concentrate pH determination. The HCO3 - and CO3 2- equilibrium equation using acidity constants developed for seawater medium was the only method able to predict correctly the concentrate pH. The outcome of this study indicated that the saturation level of the concentrate was lower than previously anticipated. This was confirmed by shutting down the acid and the antiscalants dosing without any signs of scaling over a period of 12 months. © 2011 Elsevier B.V.

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.

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

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.

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.

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.

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...

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

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 ...

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)

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...

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.

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.

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.

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)

Application of reverse osmosis membrane technology for liquid radioactive waste processing

International Nuclear Information System (INIS)

Zhao Juan

2010-01-01

Liquid radioactive waste (LRW) processing should bear an acceptable level of residual radioactivity for discharge and meet the request of energy saving and waste minimization. Reverse osmosis (RO) membrane technology has been developed as a novel process for LRW processing. Five basic operating parameters of flux, recovery factor, rejection factor, concentration factor and decontamination factor were described, and the latter two parameters were the most important. Concentration factor and decontamination factor should be as high as possible and simultaneously the operating cost for membrane filtration should be low. Technical design considerations for membrane process were discussed and optimized from the aspects of pretreatment, membrane module choice and arrangement and membrane clear out. Application and investigation of RO membrane technology for LRW processing were introduced and it should be noted that the RO membrane technology has been introduced into overseas nuclear power plants for LRW processing and interiorly in the stage of investigation. (authors)

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

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

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.

Effect of flow velocity, substrate concentration and hydraulic cleaning on biofouling of reverse osmosis feed channels

KAUST Repository

Radu, Andrea I.

2012-04-01

A two-dimensional mathematical model coupling fluid dynamics, salt and substrate transport and biofilm development in time was used to investigate the effects of cross-flow velocity and substrate availability on biofouling in reverse osmosis (RO)/nanofiltration (NF) feed channels. Simulations performed in channels with or without spacer filaments describe how higher liquid velocities lead to less overall biomass amount in the channel by increasing the shear stress. In all studied cases at constant feed flow rate, biomass accumulation in the channel reached a steady state. Replicate simulation runs prove that the stochastic biomass attachment model does not affect the stationary biomass level achieved and has only a slight influence on the dynamics of biomass accumulation. Biofilm removal strategies based on velocity variations are evaluated. Numerical results indicate that sudden velocity increase could lead to biomass sloughing, followed however by biomass re-growth when returning to initial operating conditions. Simulations show particularities of substrate availability in membrane devices used for water treatment, e.g., the accumulation of rejected substrates at the membrane surface due to concentration polarization. Interestingly, with an increased biofilm thickness, the overall substrate consumption rate dominates over accumulation due to substrate concentration polarization, eventually leading to decreased substrate concentrations in the biofilm compared to bulk liquid. © 2012 Elsevier B.V.

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

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.

“Breakthrough” osmosis and unusually high power densities in Pressure-Retarded Osmosis in non-ideally semi-permeable supported membranes

Science.gov (United States)

Yaroshchuk, Andriy

2017-01-01

Osmosis is the movement of solvent across a membrane induced by a solute-concentration gradient. It is very important for cell biology. Recently, it has started finding technological applications in the emerging processes of Forward Osmosis and Pressure-Retarded Osmosis. They use ultrathin and dense membranes supported mechanically by much thicker porous layers. Until now, these processes have been modelled by assuming the membrane to be ideally-semipermeable. We show theoretically that allowing for even minor deviations from ideal semipermeability to solvent can give rise to a previously overlooked mode of “breakthrough” osmosis. Here the rate of osmosis is very large (compared to the conventional mode) and practically unaffected by the so-called Internal Concentration Polarization. In Pressure-Retarded Osmosis, the power densities can easily exceed the conventional mode by one order of magnitude. Much more robust support layers can be used, which is an important technical advantage (reduced membrane damage) in Pressure-Retarded Osmosis. PMID:28332607

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

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.

Simultaneous nitrogen, phosphorous, and hardness removal from reverse osmosis concentrate by microalgae cultivation.

Science.gov (United States)

Wang, Xiao-Xiong; Wu, Yin-Hu; Zhang, Tian-Yuan; Xu, Xue-Qiao; Dao, Guo-Hua; Hu, Hong-Ying

2016-05-01

While reverse osmosis (RO) is a promising technology for wastewater reclamation, RO concentrate (ROC) treatment and disposal are important issues to consider. Conventional chemical and physical treatment methods for ROC present certain limitations, such as relatively low nitrogen and phosphorus removal efficiencies as well as the requirement of an extra process for hardness removal. This study proposes a novel biological approach for simultaneous removal of nitrogen, phosphorus, and calcium (Ca(2+)) and magnesium (Mg(2+)) ions from the ROC of municipal wastewater treatment plants by microalgal cultivation and algal biomass production. Two microalgae strains, Chlorella sp. ZTY4 and Scenedesmus sp. LX1, were used for batch cultivation of 14-16 days. Both strains grew well in ROC with average biomass production of 318.7 mg/L and lipid contents up to 30.6%, and nitrogen and phosphorus could be effectively removed with efficiencies of up to 89.8% and 92.7%, respectively. Approximately 55.9%-83.7% Ca(2+) could be removed from the system using the cultured strains. Mg(2+) removal began when Ca(2+) precipitation ceased, and the removal efficiency of the ion could reach up to 56.0%. The most decisive factor influencing Ca(2+) and Mg(2+) removal was chemical precipitation with increases in pH caused by algal growth. The results of this study provide a new biological approach for removing nitrogen, phosphorous, and hardness from ROC. The results suggest that microalgal cultivation presents new opportunities for applying an algal process to ROC treatment. The proposed approach serves dual purposes of nutrient and hardness reduction and production of lipid rich micro-algal biomass. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

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.

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.

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

Study on concentrating treatment test of simulated radioactive wastewater containing boron by reverse osmosis membrane in PWR NPP

International Nuclear Information System (INIS)

Ye Xinnan; Jiang Baihua; Fan Wenwen; Zhang Zhiyin; Yang Cangsheng

2015-01-01

The reverse osmosis membrane equipment in PWR NPP was employed to investigate the application of pilot scale system in the radioactive wastewater treatment at the full recirculation operation. The removal performance of the equipment for the boron and the radioactivity nuclide were studied, respectively. The experimental results show that the removal efficiency of the aromatic polyamide composite reverse osmosis membrane for boron is over 83.3% and the concentration of boron in concentrate is over 10000 mg/L. The experimental results also show that the removal efficiency of two nuclides including cobalt and cesium is over 97.9%. (authors)

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.

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.

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.

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.

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.

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.

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.

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…

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.

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.

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

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

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.

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.

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

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

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.

Using ultra-osmosis to concentrate residues upto 20% solids using 10% of the energy of conventional methods

Energy Technology Data Exchange (ETDEWEB)

O' Shea, J A

1990-01-01

In the Food Industry, generally that is, Milk, Beet, Grain and Potato processing the major energy input is the removal of water from the raw material. This is particularly important in the milk Industry where liquid milk has a water content of 88%. When the fat and protein are removed it is only 6% solid or 94% water. The consideration of Ultra-Osmosis is beneficial in its energy efficiency compared to thermal vapour recompression and also has the side benefit as being a demineralisation plant as well. Reverse Osmosis is a unique cross lined polyamide membrane. Its rejection characteristics enable it to discriminate among low molecular weight species. The pore structure of the membrane is such that a separation between sodium chloride and calcium sulphate may be accomplished. Such separations are useful in a variety of applications. The utility of the membrane is further enhanced by the simultaneous ability to concentrate the retained species. The Ultra Osmosis process based on a membrane with rejection characteristics intermediate between those common in Ultra Filtration and Reverse Osmosis opens the road to a whole new spectrum of membrane separations. 3 figs.

?Breakthrough? osmosis and unusually high power densities in Pressure-Retarded Osmosis in non-ideally semi-permeable supported membranes

OpenAIRE

Yaroshchuk, Andriy

2017-01-01

Osmosis is the movement of solvent across a membrane induced by a solute-concentration gradient. It is very important for cell biology. Recently, it has started finding technological applications in the emerging processes of Forward Osmosis and Pressure-Retarded Osmosis. They use ultrathin and dense membranes supported mechanically by much thicker porous layers. Until now, these processes have been modelled by assuming the membrane to be ideally-semipermeable. We show theoretically that allow...

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 ...

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).

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

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

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...

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

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%

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.

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 ...

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.

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.

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

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)

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.

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)

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

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...

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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

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.

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.

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.

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.

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.

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

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.

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

CONCENTRATION AND RECOVERY OF PROTEIN FROM TUNA COOKING JUICE BY FORWARD OSMOSIS

Directory of Open Access Journals (Sweden)

KHONGNAKORN W.

2016-07-01

Full Text Available Tuna cooking processing plants generate large amount of cooking juice containing a significant content of protein. Recovery and concentrating process of this valuable compound together with a low energy consumption process are of interest regarding full utilization concept and green process approach. Forward osmosis (FO was employed in this work to recover and concentrate tuna cooking juice. FO process could increase the protein concentration up to 9% with an average permeate flux of 2.54 L/m2h. The permeate flux however tended to decrease as protein concentration increased due to the impact of osmotic pressure of the feed and fouling on the membrane surface. Since tuna cooking juice consists of protein and minerals, membrane analyses indicated that fouling was more severe compared to the fouling caused by standard bovine serum albumin pure protein. However, the presence of minerals rendered it a quicker and lower energy process by comparison. These results indicated that FO is a promising technique in the recovery and concentration of tuna cooking juice protein.

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

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

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.)

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)

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

Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

Directory of Open Access Journals (Sweden)

Byung-Sik Lee

2015-12-01

Full Text Available 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 flux under electroneutrality and zero electric current conditions. The distribution coefficient which arises due to ion interactions with the membrane material and the electric potential jump at the membrane interface are included as boundary conditions in solving the equation. A high Peclet approximation is adopted to simplify the calculation, but the effect of concentration polarization is included for a more accurate prediction of separation. Cobalt and cesium are specifically selected for the experiments in order to check the separation mechanism from liquid waste composed of various radioactive nuclides and nonradioactive substances, and the results are compared with the estimated cobalt and cesium rejections of the RO membrane using the model. Experimental and calculated results are shown to be in excellent agreement. The proposed model will be very useful for the prediction of separation behavior of various radioactive nuclides by the RO membrane.

Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Sik [KEPCO Engineering and Construction, Gimcheon (Korea, Republic of)

2015-12-15

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 flux under electroneutrality and zero electric current conditions. The distribution coefficient which arises due to ion interactions with the membrane material and the electric potential jump at the membrane interface are included as boundary conditions in solving the equation. A high Peclet approximation is adopted to simplify the calculation, but the effect of concentration polarization is included for a more accurate prediction of separation. Cobalt and cesium are specifically selected for the experiments in order to check the separation mechanism from liquid waste composed of various radioactive nuclides and nonradioactive substances, and the results are compared with the estimated cobalt and cesium rejections of the RO membrane using the model. Experimental and calculated results are shown to be in excellent agreement. The proposed model will be very useful for the prediction of separation behavior of various radioactive nuclides by the RO membrane.

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.

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.

Quorum quenching bacteria can be used to inhibit the biofouling of reverse osmosis membranes.

Science.gov (United States)

Oh, Hyun-Suk; Tan, Chuan Hao; Low, Jiun Hui; Rzechowicz, Miles; Siddiqui, Muhammad Faisal; Winters, Harvey; Kjelleberg, Staffan; Fane, Anthony G; Rice, Scott A

2017-04-01

Over the last few decades, significant efforts have concentrated on mitigating biofouling in reverse osmosis (RO) systems, with a focus on non-toxic and sustainable strategies. Here, we explored the potential of applying quorum quenching (QQ) bacteria to control biofouling in a laboratory-scale RO system. For these experiments, Pantoea stewartii was used as a model biofilm forming organism because it was previously shown to be a relevant wastewater isolate that also forms biofilms in a quorum sensing (QS) dependent fashion. A recombinant Escherichia coli strain, which can produce a QQ enzyme, was first tested in batch biofilm assays and significantly reduced biofilm formation by P. stewartii. Subsequently, RO membranes were fouled with P. stewartii and the QQ bacterium was introduced into the RO system using two different strategies, direct injection and immobilization within a cartridge microfilter. When the QQ bacterial cells were directly injected into the system, N-acylhomoserine lactone signals were degraded, resulting in the reduction of biofouling. Similarly, the QQ bacteria controlled biofouling when immobilized within a microfilter placed downstream of the RO module to remove QS signals circulating in the system. These results demonstrate the proof-of-principle that QQ can be applied to control biofouling of RO membranes and may be applicable for use in full-scale plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

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...

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.

Evaluation of the treatment of reverse osmosis concentrates from municipal wastewater reclamation by coagulation and granular activated carbon adsorption.

Science.gov (United States)

Sun, Ying-Xue; Yang, Zhe; Ye, Tao; Shi, Na; Tian, Yuan

2016-07-01

Reverse osmosis concentrate (ROC) from municipal wastewater reclamation reverse osmosis (mWRRO) contains elevated concentrations of contaminants which pose potential risks to aquatic environment. The treatment of ROC from an mWRRO using granular activated carbon (GAC) combined pretreatment of coagulation was optimized and evaluated. Among the three coagulants tested, ferric chloride (FeCl3) presented relatively higher DOC removal efficiency than polyaluminium chloride and lime at the same dosage and coagulation conditions. The removal efficiency of DOC, genotoxicity, and antiestrogenic activity concentration of the ROC could achieve 16.9, 18.9, and 39.7 %, respectively, by FeCl3 coagulation (with FeCl3 dosage of 180.22 mg/L), which can hardly reduce UV254 and genotoxicity normalized by DOC of the DOM with MW activity were completely eliminated by the GAC adsorption. The results suggest that GAC adsorption combined pretreatment of FeCl3 coagulation as an efficient method to control organics, genotoxicity, and antiestrogenic activity in the ROC from mWRRO system.

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).

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)

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.

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.

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.

Evaluation of the acerola juice concentrated by reverse osmosis

Directory of Open Access Journals (Sweden)

Eliane Rodrigues dos Santos Gomes

2005-06-01

Full Text Available The aim of this study was to obtain the acerola juice using separation processes with membranes. The acerola pulp was initially defrosted and treated with 100 ppm of Citrozym Ultra L enzyme at 45ºC for one hour, then ultrafiltrated at 3 bar at 45ºC using 0.1 µm ceramic membrane, and concentrated by reverse osmosis using a spiral membrane of a compound film. The pressures on the reverse osmosis were 20, 30, and 40 bar at environmental temperature, thus, resulting a juice with 9.76, 14.56, and 17.36 ºBrix, respectively. The physicochemical characteristics of the juice were preserved and, studies on evaluation of the public acceptability, showed that 75% of the consumers liked the juice.O objetivo deste trabalho foi à obtenção de suco de acerola utilizando processos de separação com membranas. Combinou-se a ultrafiltração e a osmose inversa, visando a melhoria do processo produtivo, utilizando-se uma tecnologia limpa. Para a acerola, visou-se manter e concentrar significativamente seu teor de vitamina C, obtendo-se um suco com sabor agradável, o mais próximo possível do suco in natura. A polpa de acerola foi inicialmente descongelada e tratada com 100 ppm da enzima Citrozym Ultra L, à 45º C por 1 hora e posteriormente ultrafiltrada a 3 bar na mesma temperatura em membrana cerâmica de 0,1 µm e na seqüência, concentrada por osmose inversa utilizando membrana espiral de filme composto. As pressões na osmose inversa foram 20, 30 e 40 bar em temperatura ambiente, obtendo-se um suco com 9,76, 14,56 e 17,36 ºBrix respectivamente. As características físico-químicas foram preservadas e na avaliação da aceitabilidade, 75% dos consumidores gostaram do suco, indicando boa aceitação.

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...

Opportunities and Challenges in Application of Forward Osmosis in Food Processing.

Science.gov (United States)

Rastogi, Navin K

2016-01-01

Food processing and preservation technologies must maintain the fresh-like characteristics of food while providing an acceptable and convenient shelf life as well as assuring safety and nutritional value. Besides, the consumers' demand for the highest quality convenience foods in terms of natural flavor and taste, free from additives and preservatives necessitated the development of a number of membrane-based non-thermal approaches to the concentration of liquid foods, of which forward osmosis has proven to be the most valuable one. A series of recent publications in scientific journals have demonstrated novel and diverse uses of this technology for food processing, desalination, pharmaceuticals as well as for power generation. Its novel features, which include the concentration of liquid foods at ambient temperature and pressure without significant fouling of membrane, made the technology commercially attractive. This review aims to identify the opportunities and challenges associated with this technology. At the same time, it presents a comprehensive account of recent advances in forward osmosis technology as related to the major issues of concern in its rapidly growing applications in food processing such as concentration of fruit and vegetable juices (grape, pineapple, red raspberry, orange, and tomato juice and red radish juice) and natural food colorants (anthocyanin and betalains extracts). Several vibrant and vital issues such as recent developments in the forward osmosis membrane and concentration polarization aspects have been also addressed. The asymmetric membrane used for forward osmosis poses newer challenges to account both external and internal concentration polarization leading to significant reduction in flux. The recent advances and developments in forward osmosis membrane processes, mechanism of water transport, characteristics of draw solution and membranes as well as applications of forward osmosis in food processing have been discussed.

Fungal treatment for the removal of endocrine disrupting compounds from reverse osmosis concentrate: Identification and monitoring of transformation products of benzotriazoles.

Science.gov (United States)

Llorca, Marta; Badia-Fabregat, Marina; Rodríguez-Mozaz, Sara; Caminal, Glòria; Vicent, Teresa; Barceló, Damià

2017-10-01

The removal of 27 endocrine-disrupting compounds and related compounds (suspect effect) from a reverse osmosis concentrate using an alternative decontamination method based on a fungal treatment involving Trametes versicolor was assessed. In addition to chemical analysis, the toxicity of the treated water during the treatment was monitored using a bioluminescence inhibition test and estrogenic and anti-estrogenic tests. The compounds 1H-benzotriazole (BTZ) and two tolyltriazoles (TTZs), 4-methyl-1H-benzotriazole (4-MBTZ) and 5-methyl-1H-benzotriazole (5-MBTZ), were present in the reverse osmosis concentrate at the highest concentrations (7.4 and 12.8 μg L -1 , respectively) and were partially removed by the fungal treatment under sterile conditions (58% for BTZ and 92% for TTZs) and non-sterile conditions, although to lesser extents (32% for BTZ and 50% for TTZs). Individual biotransformation studies of BTZ and the TTZs by T. versicolor in a synthetic medium and further analysis via on-line turbulent flow chromatography coupled to an HRMS-Orbitrap allowed the tentative identification of the transformation products (TPs). Six TPs were postulated for BTZ, two TPs were postulated for 4-MBTZ, and four TPs were postulated for 5-MBTZ. Most of these TPs are suggested to have been generated by conjugation with some sugars and via the methylation of the triazole group. Only TP 148 A, postulated to be derived from the biotransformation of BTZ, was observed in the effluent of the bioreactor treating the reverse osmosis concentrate. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

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.

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.

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.

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.

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

Production of grape juice powder obtained by freeze-drying after concentration by reverse osmosis

Directory of Open Access Journals (Sweden)

Poliana Deyse Gurak

2013-12-01

Full Text Available This study aimed to evaluate the freeze-drying process for obtaining grape juice powder by reverse osmosis using 50% grape juice pre-concentrated (28.5 °Brix and 50% hydrocolloids (37.5% maltodextrin and 12.5% arabic gum. The morphology of the glassy food showed the absence of crystalline structure, which was the amorphous wall that protected the contents of the powder. The samples were stored in clear and dark containers at room temperature, evaluated for their physical (X-ray diffraction for 65 days and chemical (polyphenol content stability for 120 days. During the storage time in plastic vessels, samples remained physically stable (amorphous and the phenolic concentration was constant, indicating the potentiality of this technique to obtain a stable product with a high concentration of phenolic compounds. Therefore, the freeze-drying process promoted the encapsulation of concentrated grape juice increasing its stability and shelf life, as well as proving to be an applicable process to food industry

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

Quantification of functional groups and modeling of their ionization behavior in the active layer of FT30 reverse osmosis membrane.

Science.gov (United States)

Coronell, Orlando; Mariñas, Benito J; Zhang, Xijing; Cahill, David G

2008-07-15

A new experimental approach was developed to measure the concentration of charged functional groups (FGs) in the active layer of thin-film composite reverse osmosis (RO) and nanofiltration (NF) membranes as a function of solution pH. FT30 RO membrane, with a fully aromatic polyamide (PA) active layer sandwiched between a polysulfone support and a coating layer, was used. The experiments consisted of saturating charged FGs with heavy ion probes, and determining the ion probe concentration by Rutherford backscattering spectrometry (RBS). Deprotonated carboxylic groups were saturated with Ag+, and protonated amine groups with W04(2-). The ionization behavior of carboxylic and amine groups was modeled based on acid-base equilibrium theory. While the ionization behavior of amine groups was satisfactorily described by one dissociation constant (pKa = 4.74), two pKa values (5.23 and 8.97) were necessary to describe the titration curve of carboxylic groups. These results were consistent with the bimodal pore size distribution (PSD) of FT30 active layer reported in the literature. The calculated total concentrations of carboxylic and amine groups in the active layer of the FT30 RO membrane studied were 0.432 and 0.036 M, respectively, and the isoelectric point (IEP) was 4.7. The total concentration of carboxylic and amine groups revealed that the degree of cross-linking of the PA active layer of the FT30 RO membrane studied was 94%.

Treatment of low-level radioactive waste liquid by reverse osmosis

International Nuclear Information System (INIS)

Buckley, L.P.; Sen Gupta, S.K.; Slade, J.A.

1995-01-01

The processing of low-level radioactive waste (LLRW) liquids that result from operation of nuclear power plants with reverse osmosis systems is not common practice. A demonstration facility is operating at Chalk River Laboratories (of Atomic Energy of Canada Limited), processing much of the LLRW liquids generated at the site from a multitude of radioactive facilities, ranging from isotope production through decontamination operations and including chemical laboratory drains. The reverse osmosis system comprises two treatment steps--spiral wound reverse osmosis followed by tubular reverse osmosis--to achieve an average volume reduction factor of 30:1 and a removal efficiency in excess of 99% for most radioactive and chemical species. The separation allows the clean effluent to be discharged without further treatment. The concentrated waste stream of 3 wt% total solids is further processed to generate a solid product. The typical lifetimes of the membranes have been nearly 4000 hours, and replacement was required based on increased pressure drops and irreversible loss of permeate flux. Four years of operating experience with the reverse osmosis system, to demonstrate its practicality and to observe and record its efficiency, maintenance requirements and effectiveness, have proven it to be viable for volume reduction and concentration of LLRW liquids generated from nuclear-power-plant operations

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)

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)

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%).

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.

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.

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.

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.

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.

Epithelial Fluid Transport is Due to Electro-osmosis (80%), Plus Osmosis (20%).

Science.gov (United States)

Fischbarg, Jorge; Hernandez, Julio A; Rubashkin, Andrey A; Iserovich, Pavel; Cacace, Veronica I; Kusnier, Carlos F

2017-06-01

Epithelial fluid transport, an important physiological process shrouded in a long-standing enigma, may finally be moving closer to a solution. We propose that, for the corneal endothelium, relative proportions for the driving forces for fluid transport are 80% of paracellular electro-osmosis, and 20% classical transcellular osmosis. These operate in a cyclical process with a period of 9.2 s, which is dictated by the decrease and exhaustion of cellular Na + . Paracellular electro-osmosis is sketched here, and partially discussed as much as the subject still allows; transcellular osmosis is presented at length.

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.

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.

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

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.

Removal of radionuclides by reverse osmosis using a cellulose acetate membrane, (2)

International Nuclear Information System (INIS)

Nishimaki, Kenzo; Koyama, Akio; Saji, Minoru; Tutui, Tenson.

1990-01-01

Experiments were performed on the removal of radionuclides from radioactive liquid waste by reverse osmosis using asymmetric cellulose acetate membranes. In previous papers, we reported such removal properties as the dependence on solute concentration and the influence of co-existing material. In this paper we performed experiments on some separation properties, especially on the formation and the disappearance of concentration polarization layer of membrane surface. These experiments are necessary for the theoretical explanation of findings shown in previous papers. Concentration polarization layer is formed on the surface of the membrane, when pressurized feed solution is not stirred during reverse osmosis operation. This layer grows with elapsed time and reaches the equilibrium. The thickness of this concentration polarization layer and solute concentrations in this layer are calculated by a simple model. The formation and disappearance of this layer are experimented with intermittent stirring. The influence of intensity of stirring on the formation of concentration polarization layer is observed. These are important information on property of membrane for removing solute by reverse osmosis. (author)

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

Separation of Peptides with Forward Osmosis Biomimetic Membranes

DEFF Research Database (Denmark)

Bajraktari, Niada; Madsen, Henrik T; Gruber, Mathias Felix

2016-01-01

Forward osmosis (FO) membranes have gained interest in several disciplines for the rejection and concentration of various molecules. One application area for FO membranes that is becoming increasingly popular is the use of the membranes to concentrate or dilute high value compound solutions...

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.)

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

Advanced oxidation of iodinated X-ray contrast media in reverse osmosis brines: the influence of quenching.

Science.gov (United States)

Azerrad, Sara P; Gur-Reznik, Shirra; Heller-Grossman, Lilly; Dosoretz, Carlos G

2014-10-01

Among the main restrictions for the implementation of advanced oxidation processes (AOPs) for removal of micropollutants present in reverse osmosis (RO) brines of secondary effluents account the quenching performed by background organic and inorganic constituents. Natural organic matter (NOM) and soluble microbial products (SMP) are the main effluent organic matter constituents. The inorganic fraction is largely constituted by chlorides and bicarbonate alkalinity with sodium and calcium as main counterions. The quenching influence of these components, separately and their mixture, in the transformation of model compounds by UVA/TiO2 was studied applying synthetic brines solutions mimicking 2-fold concentrated RO secondary effluents brines. The results were validated using fresh RO brines. Diatrizoate (DTZ) and iopromide (IOPr) were used as model compound. They have been found to exhibit relative high resistance to oxidation process and therefore represent good markers for AOPs techniques. Under the conditions applied, oxidization of DTZ in the background of RO brines was strongly affected by quenching effects. The major contribution to quenching resulted from organic matter (≈70%) followed by bicarbonate alkalinity (≈30%). NOM displayed higher quenching than SMP in spite of its relative lower concentration. Multivalent cations, i.e., Ca(+2), were found to decrease effectiveness of the technique due to agglomeration of the catalyst. However this influence was lowered in presence of NOM. Different patterns of transformation were found for each model compound in which a delayed deiodination was observed for iopromide whereas diatrizoate oxidation paralleled deiodination. Copyright © 2014 Elsevier Ltd. All rights reserved.

Marine bacterial transparent exopolymer particles (TEP) and TEP precursors: Characterization and RO fouling potential

KAUST Repository

Li, Sheng

2015-10-31

This paper investigated the characteristics and membrane fouling potential of bacterial transparent exopolymer particles (TEP)/TEP precursors released from two marine bacteria, Pseudidiomarina homiensis (P. homiensis) and Pseudoalteromonas atlantica (P. atlantica), isolated from the Red Sea. Results showed that both bacteria grew at the similar rate, but the production of TEP/TEP precursors from P. atlantica was higher than that from P. homiensis. During the 168. h of incubation time, production rates of TEP/TEP precursors from P. atlantica and P. homiensis were 0.30 and 0.08 xanthan gum eq. mg/L-h, respectively. Isolated bacterial TEP precursors were mainly biopolymer, and P. atlantica produced a significantly higher concentration of biopolymer than that produced by P. homiensis. TEP/TEP precursors from both marine bacteria possessed protein-like material and were very similar in composition to previously reported foulants isolated from a fouled reverse osmosis (RO) membrane. Bacterial TEP/TEP precursors mostly consisted of aliphatic hydrocarbon from amino acids and amide group carbon of proteins (around 55%). Bacterial TEP precursors caused obvious fouling on RO membranes, which may create an ideal environment for bacteria attachment and promote to biofouling.

Arsenic Removal Efficiency in Aqueous Solutions Using Reverse Osmosis and Zero-Valent Iron Nanoparticles

Directory of Open Access Journals (Sweden)

Niloofar Saboori

2018-01-01

Full Text Available Arsenic is one of the most hazardous pollutants of water resources which threaten human health as well as animals. Therefore arsenic removal from water resources is the priority of health programs. There are several ways to remove arsenic. In this study, reverse osmosis and zero-valent iron nanoparticles methods have been used in a laboratory scale. To perform the test, the variables of temperature, arsenic concentration, pH, iron nanoparticle concentration and mixing time were considered. The results indicated that in both methods of reverse osmosis and iron nanoparticle, through increasing arsenic concentration, arsenic removal efficiency has been also increased. At concentration of 1.5 mg per litre in reverse osmosis method, the maximum efficiency was achieved by 98% and 95.2% removal of arsenic respectively. The effect of temperature and pH were similar in reverse osmosis; by increasing these two variables, arsenic removal percentage also increased. The highest removal rates of 95.98% and 95.56% were observed at pH 9 and Temperature 30oC respectively. The results indicated that in iron nanoparticles method the arsenic removal efficiency increases by increasing mixing time and temperature, while it decreases with increasing pH.

Treatment of simulated plutonium-containing wastewater by ultrafiltration-reverse osmosis technology

International Nuclear Information System (INIS)

Xiong Zhonghua; Fan Xianhua; Luo Deli; Wang Tuo; Chen Qi

2008-01-01

Ultrafiltration and reverse osmosis were employed for the treatment of low level radioactive water containing plutonium. The system consists of ultrafiltration module with hollow fibre membrane and reverse osmosis module with spiral membrane. The decontamination efficiency and volume concentration ratio affected by technical parameters were explored in the experiment. The results show that the decontamination efficiency achieves 99.94% and the volume concentration ratio achieves 12.5 at pH=10 for solution fed into the membrane separation system. This technology will be applied in radioactive waste minimization as a new treatment method. (authors)

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.

Effects of must concentration techniques on wine isotopic parameters.

Science.gov (United States)

Guyon, Francois; Douet, Christine; Colas, Sebastien; Salagoïty, Marie-Hélène; Medina, Bernard

2006-12-27

Despite the robustness of isotopic methods applied in the field of wine control, isotopic values can be slightly influenced by enological practices. For this reason, must concentration technique effects on wine isotopic parameters were studied. The two studied concentration techniques were reverse osmosis (RO) and high-vacuum evaporation (HVE). Samples (must and extracted water) have been collected in various French vineyards. Musts were microfermented at the laboratory, and isotope parameters were determined on the obtained wine. Deuterium and carbon-13 isotope ratios were studied on distilled ethanol by nuclear magnetic resonance (NMR) and isotope ratio mass spectrometry (IRMS), respectively. The oxygen-18 ratio was determined on extracted and wine water using IRMS apparatus. The study showed that the RO technique has a very low effect on isotopic parameters, indicating that this concentration technique does not create any isotopic fractionation, neither at sugar level nor at water level. The effect is notable for must submitted to HVE concentration: water evaporation leads to a modification of the oxygen-18 ratio of the must and, as a consequence, ethanol deuterium concentration is also modified.

N-nitrosodimethylamine (NDMA) removal by reverse osmosis and UV treatment and analysis via LC-MS/MS.

Science.gov (United States)

Plumlee, Megan H; López-Mesas, Montserrat; Heidlberger, Andy; Ishida, Kenneth P; Reinhard, Martin

2008-01-01

N-nitrosodimethylamine (NDMA) is a probable human carcinogen found in ng/l concentrations in chlorinated and chloraminated water. A method was developed for the determination of ng/l levels of NDMA using liquid chromatography-tandem mass spectrometry (LC-MS/MS) preceded by sample concentration via solid-phase extraction with activated charcoal. Recoveries were greater than 90% and allowed a method reporting limit as low as 2ng/l. Using this method, the removal of NDMA was determined for the Interim Water Purification Facility (IWPF), an advanced wastewater treatment facility operated by the Orange County Water District (OCWD) in Southern California. The facility treats effluent from an activated sludge treatment plant with microfiltration (MF), reverse osmosis (RO), and an ultraviolet-hydrogen peroxide advanced oxidation process (UV-AOP). Six nitrosamines were surveyed: NDMA, N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosodi-n-propylamine (NDPA), N-nitrosopiperidine (NPip), and N-nitrosopyrrolidine (NPyr). Only NDMA was detected and at all treatment steps in the IWPF, with influent concentrations ranging from 20 to 59 ng/l. Removals for RO and UV ranged from 24% to 56% and 43% to 66%, respectively. Overall, 69+/-7% of the original NDMA concentration was removed from the product water across the advanced treatment process and, in combination with blending, the final concentration did not exceed the California drinking water notification level of 10 ng/l. NDMA removal data are consistent with findings reviewed for other advanced treatment facilities and laboratory studies.

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.

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.

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.

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.

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)

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…

ETV REPORT: EVALUATION OF HYDROMETRICS, INC., HIGH EFFICIENCY REVERSE OSMOSIS (HERO™) INDUSTRIAL WASTEWATER TREATMENT SYSTEM

Science.gov (United States)

Hydrometrics, founded in 1979 and located in Helena, MT, manufactures a commercial-ready High Efficiency Reverse Osmosis (HERO™) industrial wastewater treatment system. The system uses a three-stage reverse osmosis process to remove and concentrate metals for recovery while prod...

Integrating electrochemical oxidation into forward osmosis process for removal of trace antibiotics in wastewater.

Science.gov (United States)

Liu, Pengxiao; Zhang, Hanmin; Feng, Yujie; Shen, Chao; Yang, Fenglin

2015-10-15

During the rejection of trace pharmaceutical contaminants from wastewater by forward osmosis (FO), disposal of the FO concentrate was still an unsolved issue. In this study, by integrating the advantages of forward osmosis and electrochemical oxidation, a forward osmosis process with the function of electrochemical oxidation (FOwEO) was established for the first time to achieve the aim of rejection of trace antibiotics from wastewater and treatment of the concentrate at the same time. Results demonstrated that FOwEO (current density J=1 mA cm(-2)) exhibited excellent rejections of antibiotics (>98%) regardless of different operation conditions, and above all, antibiotics in the concentrate were well degraded (>99%) at the end of experiment (after 3h). A synergetic effect between forward osmosis and electrochemical oxidation was observed in FOwEO, which lies in that antibiotic rejections by FO were enhanced due to the degradation of antibiotics in the concentrate, while the electrochemical oxidation capacity was improved in the FOwEO channel, of which good mass transfer and the assist of indirect oxidation owing to the reverse NaCl from draw solution were supposed to be the mechanism. This study demonstrated that the FOwEO has the capability to thoroughly remove trace antibiotics from wastewater. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

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.

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)

Removal of radionuclides from liquid streams by reverse osmosis

International Nuclear Information System (INIS)

Deshmukh, U.A.; Ramachandhran, V.; Misra, B.M.

1987-01-01

Separation of radionuclides in trace concentrations by cellulose acetate membranes has been under investigation in this laboratory, and the behaviour of some important radionuclides such as 137 Cs and 90 Sr under reverse osmosis has been reported earlier. The present work deals with a few other typical radionuclides such as 60 Co, 103 Ru and 131 I which are not fully amenable to conventional methods for their removal. Separation of these radionuclides from liquid streams by the reverse osmosis process was studied using a small reverse osmosis test cell. Various parameters like membrane porosity, applied pressure and feed activity levels were investigated. Cellulose acetate membranes offer reasonable separation of 60 Co, 103 Ru and 131 I radionuclides, indicating the potential of reverse osmosis for treatment of effluents containing these radioisotopes. The percent separation is found to be in the order of Co > Ru > I. The percent radioactive separation improves with increases in feed activity. The performance data are explained in terms of solution-diffusion mechanism. It appears that the separation of radionuclides is not governed by diffusion alone, but by the interaction of solutes with the membranes. (author)

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.

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

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.)

Characterization and Evaluation of the Improved Performance of Modified Reverse Osmosis Membranes by Incorporation of Various Organic Modifiers and SnO2 Nanoparticles

Directory of Open Access Journals (Sweden)

Kh. M. AL-Sheetan

2015-01-01

Full Text Available Reverse osmosis (RO membranes modified with SnO2 nanoparticles of varied concentrations (0.001–0.1 wt.% were developed via in situ interfacial polymerization (IP of trimesoyl chloride (TMC and m-phenylenediamine (MPD on nanoporous polysulfone supports. The nanoparticles dispersed in the dense nodular polyamide on the polysulfone side. The effects of IP reaction time and SnO2 loading on membrane separation performance were studied. The modified reverse osmosis membranes were characterized by scanning electron microscopy (SEM, X-ray diffractometer (XRD, energy dispersive X-ray spectroscopy (EDX, transmission electron microscopy (TEM, contact angle measurement, and atomic force microscopy (AFM. The synthesized SnO2 nanoparticles size varies between 10 and 30 nm. The results exhibited a smooth membrane surface and average surface roughness from 31 to 68 nm. Moreover, hydrophilicity was enhanced and contact angle decreased. The outcomes showed that an IP reaction time was essential to form a denser SnO2-polyamide layer for higher salt rejection, the developed reverse osmosis membranes with the incorporation of the SnO2 nanoparticles were examined by measuring permeate fluxes and salt rejection, and the permeate flux increased from 26 to 43.4 L/m2·h, while salt rejection was high at 98% (2000 ppm NaCl solution at 225 psi (1.55 MPa, 25°C.

Integrated Wireless Monitoring and Control System in Reverse Osmosis Membrane Desalination Plants

Directory of Open Access Journals (Sweden)

Al Haji Ahmad

2015-01-01

Full Text Available The operational processes of the Reverse Osmosis (RO membrane desalination plants require continuous monitoring through the constant attendance of operators to ensure proper productivity and minimize downtime and prevent membrane failure. Therefore, the plant must be equipped with a control system that monitors and controls the operational variables. Monitoring and controlling the affecting parameters are critical to the evaluation of the performance of the desalination plant, which will help the operator find and resolve problems immediately. Therefore, this paper was aimed at developing an RO unit by utilizing a wireless sensor network (WSN system. Hence, an RO pilot plant with a feed capacity of 1.2 m3/h was utilized, commissioned, and tested in Kuwait to assess and verify the performance of the integrated WSN in RO membrane desalination system. The investigated system allowed the operators to remotely monitor the operational process of the RO system. The operational data were smoothly recorded and monitored. Furthermore, the technical problems were immediately determined, which reduced the time and effort in rectifying the technical problems relevant to the RO performance. The manpower requirements of such treatment system were dramatically reduced by about 50%. Based on a comparison between manual and wireless monitoring operational processes, the availability of the integrated RO unit with a wireless monitoring was increased by 10%

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.

Transport properties of mixed metallic salts through reverse osmosis membrane

International Nuclear Information System (INIS)

Koyama, Akio; Nishimaki, Kenzo

1991-01-01

Applicability of reverse osmosis to the treatment of radioactive liquid waste was investigated. In previous papers, we showed the ability of reverse osmosis to decontaminate liquid waste which contains ionic radionuclides with chloride ion. When sulfate ion coexists with chloride, logarithms of DFs of one cation are approximately expressed by a linear function of logarithms of SO 4 2- /Cl - ratio. In this paper, we investigate the relation between DFs and concentrations of coexisting ions in multicomponent cation/anion system. As a result of this study, DFs of cations change more seriously with coexisting anions composition than with cations. In the case of anion, these influences are the reverse. Logarithms of DFs of cations and anions are expressed by linear equation with the two variables, logarithmic concentration ratio of univalent/divalent cations and logarithmic concentration ratio of SO 4 2- /Cl - . (author)

Treatment of radioactive liquid waste by tubular type reverse osmosis module

International Nuclear Information System (INIS)

Nishimaki, Kenzo; Koyama, Akio; Tsutsui, Tenson; Mori, Koji.

1988-01-01

The applicability of reverse osmosis to radioactive liquid waste treatment was studied using a tubular type module. When four modules were used in a series, circulating volume of concentrate was much greater than permeate volume, therefore solute concentration and circulating rate of concentrate can be assumed uniform in the axial direction of the modules. DFs of stable elements contained in the tap water were 36-40 for Na, 50-55 for K, 170-250 for Mg and 90-160 for Ca. When Na concentration increased about ten times, DFs for all elements slightly decreased. For actual liquid waste tagged with radionuclides, DFs were in the range of 35-40 for 134 Cs, 150-200 for 85 Sr, and 180-280 for 58 Co. These DF values indicate the possibility of the treatment of low radioactive liquid waste by reverse osmosis. (author)

Recovery of iron after Fenton-like secondary treatment of olive mill wastewater by nano-filtration and low-pressure reverse osmosis membranes

International Nuclear Information System (INIS)

Ochando-Pulido, J.M.; Victor-Ortega, M.D.; Martinez-Ferez, A.

2016-01-01

In this work, the performances of novel nano-filtration (NF) and low-pressure reverse osmosis (RO) polymeric membranes were examined with the aim of recovering the iron used as catalyst in former secondary treatment based on the Fenton-like advanced oxidation of olive mill wastewater (OMW). Results highlight that both membranes exhibit a good performance towards the rejection of iron (99.1% for the NF membrane vs. 100% for the low-pressure RO membrane) in the secondary-treated OMW effluent, thus permitting the recovery of iron in the concentrate stream in order to recycle it back into the oxidation reactor to reduce catalyst consumption. Finally, the permeate streams could be re-used for irrigation. Major productivity was observed by the selected NF membrane, about 47.4 L/hm2 upon 9 bar, whereas 30.9 L/hm2 could be yielded with the RO membrane under an operating pressure of 8 bar. Moreover, a sensibly lower fouling index was measured on the NF membrane (0.0072 in contrast with 0.065), which ensures major steady-state performance on this membrane and a longer service lifetime. This also results in lower required membrane area and membrane plant over dimension (4 modules in case of RO operation whereas only 2 modules for NF). [es

Study of Separation and Fouling of Reverse Osmosis Membranes during Model Hydrolysate Solution Filtration.

Science.gov (United States)

Ajao, Olumoye; Rahni, Mohamed; Marinova, Mariya; Chadjaa, Hassan; Savadogo, Oumarou

2017-12-15

Prehydrolysate, a dilute solution consisting mainly of pentoses, hexoses, and lesser quantities of organic acids, furfural and phenolics, is generated in the Kraft dissolving pulp process. An obstacle facing the valorization of the solution in hemicellulose biorefineries, by conversion of the sugars into bioproducts such as furfural, is the low sugar concentration. Membrane filtration is typically proposed in several hemicellulose based biorefineries for concentrating the solution, although they are usually generated using different wood species, pretreatment methods, and operating conditions. However, the chemical composition of the solutions is generally not considered. Also, the combined effect of composition and operating conditions is rarely investigated for biorefinery applications. The purpose of this work was to determine the impact of the prehydrolysate composition and operating parameters on the component separation and permeate flux during membrane filtration. Using model prehydrolysate solutions, two commercial reverse osmosis (RO) membranes were screened, and one was selected for use, based on its higher sugar and acetic acid retention. A Taguchi L18 experimental design array was then applied to determine the dominant parameters and limiting factors. Results showed that the feed pressure and temperature have the highest impact on permeate flux, but the least effect on sugar retention. Further experiments to quantify flux decline, due to fouling and osmotic pressure, showed that furfural has the highest membrane fouling tendency, and can limit the lifetime of the membrane. Regeneration of the membrane by cleaning with a sodium hydroxide solution is also effective for reversing fouling. It has been demonstrated that RO can efficiently and sustainably concentrate wood prehydrolysate.

Study of Separation and Fouling of Reverse Osmosis Membranes during Model Hydrolysate Solution Filtration

Directory of Open Access Journals (Sweden)

Olumoye Ajao

2017-12-01

Full Text Available Prehydrolysate, a dilute solution consisting mainly of pentoses, hexoses, and lesser quantities of organic acids, furfural and phenolics, is generated in the Kraft dissolving pulp process. An obstacle facing the valorization of the solution in hemicellulose biorefineries, by conversion of the sugars into bioproducts such as furfural, is the low sugar concentration. Membrane filtration is typically proposed in several hemicellulose based biorefineries for concentrating the solution, although they are usually generated using different wood species, pretreatment methods, and operating conditions. However, the chemical composition of the solutions is generally not considered. Also, the combined effect of composition and operating conditions is rarely investigated for biorefinery applications. The purpose of this work was to determine the impact of the prehydrolysate composition and operating parameters on the component separation and permeate flux during membrane filtration. Using model prehydrolysate solutions, two commercial reverse osmosis (RO membranes were screened, and one was selected for use, based on its higher sugar and acetic acid retention. A Taguchi L18 experimental design array was then applied to determine the dominant parameters and limiting factors. Results showed that the feed pressure and temperature have the highest impact on permeate flux, but the least effect on sugar retention. Further experiments to quantify flux decline, due to fouling and osmotic pressure, showed that furfural has the highest membrane fouling tendency, and can limit the lifetime of the membrane. Regeneration of the membrane by cleaning with a sodium hydroxide solution is also effective for reversing fouling. It has been demonstrated that RO can efficiently and sustainably concentrate wood prehydrolysate.

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.

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.

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

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)

Layer-by-Layer Assembly for Preparation of High-Performance Forward Osmosis Membrane

Science.gov (United States)

Yang, Libin; Zhang, Jinglong; Song, Peng; Wang, Zhan

2018-01-01

Forward osmosis (FO) membrane with high separation performance is needed to promote its practical applications. Herein, layer-by-layer (LbL) approach was used to prepare a thin and highly cross-linked polyamide layer on a polyacrylonitrile substrate surface to prepare a thin-film composite forward osmosis (TFC-FO) membrane with enhanced FO performance. The effects of monomer concentrations and assembly cycles on the performance of the TFC-FO membranes were systematically investigated. Under the optimal preparation condition, TFC-FO membrane achieved the best performance, exhibiting the water flux of 14.4/6.9 LMH and reverse salt flux of 7.7/3.8 gMH under the pressure retarded osmosis/forward osmosis (PRO/FO) mode using 1M NaCl as the draw against a DI-water feed, and a rejection of 96.1% for 2000 mg/L NaCl aqueous solution. The result indicated that layer-by-layer method was a potential method to regulate the structure and performance of the TFC-FO membrane.

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.

Coagulation and ultrafiltration in seawater reverse osmosis pretreatment

NARCIS (Netherlands)

Tabatabai, S.A.A.

2014-01-01

Seawater desalination is a globally expanding coastal industry with an installed capacity of over 80 million m3/day. Algal blooms pose a challenge to the operation of seawater reverse osmosis (SWRO) membranes and pre-treatment systems due to high concentrations of algal cells and algal organic

Ozonation of nanofiltration permeate of whey before processing by reverse osmosis

Directory of Open Access Journals (Sweden)

Zmievskii Yurii G.

2017-01-01

Full Text Available During nanofiltration processing of whey a significant amount of permeate is generated. In some cases this permeate is treated by reverse osmosis to get purified water for technological needs. Dry substances are not used, because they contain practically the same amount of organic and inorganic components. Mineral substances can be used for the mineralization of drinking water purified by reverse osmosis. However, the presence of organic compounds complicates the process of separation, as well as reduces the specific productivity of reverse osmosis membranes at the concentration stage. Therefore, the search for methods of destruction and removal of organic components is grounded. In the presented work, experimental studies of ozonation and sorption of organic compounds by activated carbon were carried. It has been shown that ozonation improves the degree of sorption purification by six times. Sequential treatment with ozone and subsequent filtration through the layer of activated carbon improves the specific productivity of reverse osmosis membranes by 30% at the stage of treatment of the nanofiltration permeate, while their selectivity remains unchanged.

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.

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.

Studies on osmotic concentration of radioactive effluents

International Nuclear Information System (INIS)

Thomas, K.C.; Ramachandhran, V.; Misra, B.M.

1986-01-01

The potential of direct osmosis for concentrating radioactive effluents is examined on the laboratory scale. Studies were carried out using asymmetric cellulose acetate membranes of a range of porosities under varying salinity gradients. A suitable bench scale osmotic concentrator employing tubular membrane systems has been fabricated and tested. An attempt to understand the mechanism of water permeation under osmotic and hydrostatic gradients has been made based on the irreversible thermodynamic approach. The solute separation of sodium chloride and radionuclides under osmosis is in the range of 85 to 95% for various osmotic sink solutions. The osmotic water flux is observed to be lower than the hydraulic water flux under reverse osmosis conditions. While the solute separation increases with an increase in annealing temperature, water flux decreases for both osmosis and reverse osmosis systems for various feed salinities. The effect of concentration polarization is analysed, and the effect of feed and osmotic sink velocity on the performance of the osmotic concentrator has also been studied. (orig.)

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.

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.

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.

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.

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...

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.

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.

Effect of DS Concentration on the PRO Performance Using a 5-Inch Scale Cellulose Triacetate-Based Hollow Fiber Membrane Module

Directory of Open Access Journals (Sweden)

Masahiro Yasukawa

2018-05-01

Full Text Available In this study, pressure-retarded osmosis (PRO performance of a 5-inch scale cellulose triacetate (CTA-based hollow fiber (HF membrane module was evaluated under a wide range of operating conditions (0.0–6.0 MPa of applied pressure, 0.5–2.0 L/min feed solution (FS inlet flow rate, 1.0–6.0 L/min DS inlet flow rate and 0.1–0.9 M draw solution (DS concentration by using a PRO/reverse osmosis (RO hybrid system. The subsequent RO system for DS regeneration enabled the evaluation of the steady-stated module performance. In the case of pilot-scale module operation, since the DS dilution and the feed solution (FS up-concentration had occurred and was not negligible, unlike the lab-scale experiment, PRO performance strongly depended on operating conditions such as inlet flow rates of both the DS and FS concentration. To compare the module performance with different configurations, we proposed a converted parameter in which a difference of the packing density between the spiral wound (SW and the HF module was fairly considered. In the case of HF configuration, because of high packing density, volumetric-based performance was higher than that of SW module, that is, the required number of the module would be less than that of SW module in a full-scale PRO plant.

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.

Asymmetric polivinylidenfluoride (PVDF) radiation grafted membranes: Preparation and performance in reverse osmosis application

International Nuclear Information System (INIS)

Vigo, F.; Capannelli, G.; Uliana, C.; Munari, S.

1981-01-01

A new type of reverse osmosis membrane has been synthesized. Membranes were prepared starting from asymmetric PVDF films, obtained by the casting and gelation technique and modified by radiochemical grafting and sulphonation. These membranes were tested in an RO laboratory plant and their performances were determined as a function of preparative parameters. The influences of evaporation time and temperature grafting and solvents were investigated. These membranes exhibit permeabilities as high as 2000 1/m 2 d and sodium chloride rejections up to 70%. (orig.)

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.)

Performance Limiting Effects in Power Generation from Salinity Gradients by Pressure Retarded Osmosis

KAUST Repository

Yip, Ngai Yin

2011-12-01

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 in pressure retarded osmosis-external concentration polarization, internal concentration polarization, and reverse draw salt flux-and offer insights on the design criteria of a high performance pressure retarded osmosis power generation system. Thin-film composite polyamide membranes were chemically modified to produce a range of membrane transport properties, and the water and salt permeabilities were characterized to determine the underlying permeability-selectivity trade-off relationship. We show that power density is constrained by the trade-off between permeability and selectivity of the membrane active layer. This behavior is attributed to the opposing influence of the beneficial effect of membrane water permeability and the detrimental impact of reverse salt flux coupled with internal concentration polarization. Our analysis reveals the intricate influence of active and support layer properties on power density and demonstrates that membrane performance is maximized by tailoring the water and salt permeabilities to the structural parameters. An analytical parameter that quantifies the relative influence of each performance limiting phenomena is employed to identify the dominant effect restricting productivity. External concentration polarization is shown to be the main factor limiting performance at high power densities. Enhancement of the hydrodynamic flow conditions in the membrane feed channel reduces external concentration polarization and thus, yields improved power density. However, doing so will also incur additional operating costs due to the accompanying hydraulic pressure loss. This study demonstrates that by thoughtful selection of the membrane properties and hydrodynamic conditions, the detrimental

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.

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)

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)

A pilot-scale forward osmosis membrane system for concentrating low-strength municipal wastewater: performance and implications

Science.gov (United States)

Wang, Zhiwei; Zheng, Junjian; Tang, Jixu; Wang, Xinhua; Wu, Zhichao

2016-02-01

Recovery of nutrients and energy from municipal wastewater has attracted much attention in recent years; however, its efficiency is significantly limited by the low-strength properties of municipal wastewater. Herein, we report a pilot-scale forward osmosis (FO) system using a spiral-wound membrane module to concentrate real municipal wastewater. Under active layer facing feed solution mode, the critical concentration factor (CCF) of this FO system was determined to be 8 with 0.5 M NaCl as draw solution. During long-term operation at a concentration factor of 5, (99.8 ± 0.6)% of chemical oxygen demand and (99.7 ± 0.5)% of total phosphorus rejection rates could be achieved at a flux of 6 L/(m2 h) on average. In comparison, only (48.1 ± 10.5)% and (67.8 ± 7.3)% rejection of ammonium and total nitrogen were observed. Cake enhanced concentration polarization is a major contributor to the decrease of water fluxes. The fouling also led to the occurrence of a cake reduced concentration polarization effect, improving ammonium rejection rate with the increase of operation time in each cycle. This work demonstrates the applicability of using FO process for wastewater concentrating and also limitations in ammonium recovery that need further improvement in future.

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

Sorption of Arsenic from Desalination Concentrate onto Drinking Water Treatment Solids: Operating Conditions and Kinetics

Directory of Open Access Journals (Sweden)

Xuesong Xu

2018-01-01

Full Text Available Selective removal of arsenic from aqueous solutions with high salinity is required for safe disposal of the concentrate and protection of the environment. The use of drinking water treatment solids (DWTS to remove arsenic from reverse osmosis (RO concentrate was studied by batch sorption experiments. The impacts of solution chemistry, contact time, sorbent dosage, and arsenic concentration on sorption were investigated, and arsenic sorption kinetics and isotherms were modeled. The results indicated that DWTS were effective in removing arsenic from RO concentrate. The arsenic sorption process followed a pseudo-second-order kinetic model. Multilayer adsorption was simulated by Freundlich equation. The maximum sorption capacities were calculated to be 170 mg arsenic per gram of DWTS. Arsenic sorption was enhanced by surface precipitation onto the DWTS due to the high amount of calcium in the RO concentrate and the formation of ternary complexes between arsenic and natural organic matter (NOM bound by the polyvalent cations in DWTS. The interactions between arsenic and NOM in the solid phase and aqueous phase exhibited two-sided effects on arsenic sorption onto DWTS. NOM in aqueous solution hindered the arsenic sorption onto DWTS, while the high organic matter content in solid DWTS phase enhanced arsenic sorption.

21 CFR 177.2550 - Reverse osmosis membranes.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Reverse osmosis membranes. 177.2550 Section 177... Components of Articles Intended for Repeated Use § 177.2550 Reverse osmosis membranes. Substances identified in paragraph (a) of this section may be safely used as reverse osmosis membranes intended for use in...

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.

Reverse osmosis treatment in CO_2 + O_2 to the application of the in-situ leaching of uranium

International Nuclear Information System (INIS)

Ruan Zhilong; Li Xilong; Yang Shaowu

2014-01-01

Advantages and disadvantages of various groundwater management methods, combined with CO_2 + O_2 characteristics of in situ leaching uranium mining process, use reverse osmosis wastewater treatment technology, has carried on the laboratory test, field condition test and industrial test. Obtained by indoor experiment and field conditions for Cl"- ion concentration variation characteristics; Reverse osmosis treatment effect of wastewater is verified by industrial test, obtained the technical parameters and consumption data, as well as the leaching liquid and adsorption tail liquid pH, SO_4"2"-; Cl"- in the plasma concentration monitoring, and further prove that the reverse osmosis treatment technology is suitable for in-situ leaching of uranium in CO_2 + O_2 in wastewater treatment. (authors)

Electro-Fenton oxidation of reverse osmosis concentrate from sanitary landfill leachate: Evaluation of operational parameters.

Science.gov (United States)

Fernandes, Annabel; Labiadh, Lazhar; Ciríaco, Lurdes; Pacheco, Maria José; Gadri, Abdellatif; Ammar, Salah; Lopes, Ana

2017-10-01

The electro-Fenton oxidation of a concentrate from reverse osmosis of a sanitary landfill leachate, with an initial chemical oxygen demand (COD) of 42 g L -1 , was carried out using a carbon-felt cathode and a boron doped diamond anode. The influence of the applied current intensity, initial pH and dissolved iron initial concentration on the electro-Fenton process was assessed. For the experimental conditions used, results showed that the initial pH is the parameter that more strongly influences the current efficiency of the electro-Fenton process, being this influence more pronounced on the oxidation rate than on the mineralization rate of the organic matter. The increase in iron initial concentration was found to be detrimental, since the natural amount of iron present in the effluent, 73 mg L -1 of total iron and 61 mg L -1 of dissolved iron, was sufficient to ensure the electro-Fenton process at the applied intensities - 0.2-1.4 A. For the more favourable conditions studied, initial pH of 3 and natural iron concentration, it was found an increase in the organic load and nitrogen removals with the applied current intensity. For the highest current intensity applied, a COD removal of 16.7 g L -1 was achieved after 8-h experiments. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Performance Evaluation of Absorbent Solution for Draw Solute Recovery in Forward Osmosis Desalination Process

International Nuclear Information System (INIS)

Kim, Young; Lee, Jong Hoon; Lee, Kong Hoon; Kim, Yu-Chang; Oh, Dong Wook; Lee, Jungho

2013-01-01

Although forward osmosis desalination technology has drawn substantial attention as a next-generation desalination method, the energy efficiency of its draw solution treatment process should be improved for its commercialization. When ammonium bicarbonate is used as the draw solute, the system consists of forward-osmosis membrane modules, draw solution separation and recovery processes. Mixed gases of ammonia and carbon dioxide generated during the draws solution separation, need to be recovered to re-concentrate ammonium bicarbonate solution, for continuous operation as well as for the economic feasibility. The diluted ammonium bicarbonate solution has been proposed as the absorbent for the draw solution regeneration. In this study, experiments are conducted to investigate performance and features of the absorption corresponding to absorbent concentration. It is concluded that ammonium bicarbonate solution can be used to recover the generated ammonia and carbon dioxide. The results will be applied to design and operation of pilot-scale forward-osmosis desalination system

Performance Evaluation of Absorbent Solution for Draw Solute Recovery in Forward Osmosis Desalination Process

Energy Technology Data Exchange (ETDEWEB)

Kim, Young; Lee, Jong Hoon; Lee, Kong Hoon; Kim, Yu-Chang; Oh, Dong Wook; Lee, Jungho [Korea Institute of Machinery Materials, Daejeon (Korea, Republic of)

2013-04-15

Although forward osmosis desalination technology has drawn substantial attention as a next-generation desalination method, the energy efficiency of its draw solution treatment process should be improved for its commercialization. When ammonium bicarbonate is used as the draw solute, the system consists of forward-osmosis membrane modules, draw solution separation and recovery processes. Mixed gases of ammonia and carbon dioxide generated during the draws solution separation, need to be recovered to re-concentrate ammonium bicarbonate solution, for continuous operation as well as for the economic feasibility. The diluted ammonium bicarbonate solution has been proposed as the absorbent for the draw solution regeneration. In this study, experiments are conducted to investigate performance and features of the absorption corresponding to absorbent concentration. It is concluded that ammonium bicarbonate solution can be used to recover the generated ammonia and carbon dioxide. The results will be applied to design and operation of pilot-scale forward-osmosis desalination system.

Algal toxins and reverse osmosis desalination operations: Laboratory bench testing and field monitoring of domoic acid, saxitoxin, brevetoxin and okadaic acid

KAUST Repository

Seubert, Erica L.

2012-12-01

The occurrence and intensity of harmful algal blooms (HABs) have been increasing globally during the past few decades. The impact of these events on seawater desalination facilities has become an important topic in recent years due to enhanced societal interest and reliance on this technology for augmenting world water supplies. A variety of harmful bloom-forming species of microalgae occur in southern California, as well as many other locations throughout the world, and several of these species are known to produce potent neurotoxins. These algal toxins can cause a myriad of human health issues, including death, when ingested via contaminated seafood. This study was designed to investigate the impact that algal toxin presence may have on both the intake and reverse osmosis (RO) desalination process; most importantly, whether or not the naturally occurring algal toxins can pass through the RO membrane and into the desalination product. Bench-scale RO experiments were conducted to explore the potential of extracellular algal toxins contaminating the RO product. Concentrations exceeding maximal values previously reported during natural blooms were used in the laboratory experiments, with treatments comprised of 50 μg/L of domoic acid (DA), 2 μg/L of saxitoxin (STX) and 20 μg/L of brevetoxin (PbTx). None of the algal toxins used in the bench-scale experiments were detectable in the desalinated product water. Monitoring for intracellular and extracellular concentrations of DA, STX, PbTx and okadaic acid (OA) within the intake and desalinated water from a pilot RO desalination plant in El Segundo, CA, was conducted from 2005 to 2009. During the five-year monitoring period, DA and STX were detected sporadically in the intake waters but never in the desalinated water. PbTx and OA were not detected in either the intake or desalinated water. The results of this study demonstrate the potential for HAB toxins to be inducted into coastal RO intake facilities, and the

Algal toxins and reverse osmosis desalination operations: Laboratory bench testing and field monitoring of domoic acid, saxitoxin, brevetoxin and okadaic acid

KAUST Repository

Seubert, Erica L.; Trussell, Shane; Eagleton, John; Schnetzer, Astrid; Cetinić, Ivona; Lauri, Phil; Jones, Burton; Caron, David A.

2012-01-01

The occurrence and intensity of harmful algal blooms (HABs) have been increasing globally during the past few decades. The impact of these events on seawater desalination facilities has become an important topic in recent years due to enhanced societal interest and reliance on this technology for augmenting world water supplies. A variety of harmful bloom-forming species of microalgae occur in southern California, as well as many other locations throughout the world, and several of these species are known to produce potent neurotoxins. These algal toxins can cause a myriad of human health issues, including death, when ingested via contaminated seafood. This study was designed to investigate the impact that algal toxin presence may have on both the intake and reverse osmosis (RO) desalination process; most importantly, whether or not the naturally occurring algal toxins can pass through the RO membrane and into the desalination product. Bench-scale RO experiments were conducted to explore the potential of extracellular algal toxins contaminating the RO product. Concentrations exceeding maximal values previously reported during natural blooms were used in the laboratory experiments, with treatments comprised of 50 μg/L of domoic acid (DA), 2 μg/L of saxitoxin (STX) and 20 μg/L of brevetoxin (PbTx). None of the algal toxins used in the bench-scale experiments were detectable in the desalinated product water. Monitoring for intracellular and extracellular concentrations of DA, STX, PbTx and okadaic acid (OA) within the intake and desalinated water from a pilot RO desalination plant in El Segundo, CA, was conducted from 2005 to 2009. During the five-year monitoring period, DA and STX were detected sporadically in the intake waters but never in the desalinated water. PbTx and OA were not detected in either the intake or desalinated water. The results of this study demonstrate the potential for HAB toxins to be inducted into coastal RO intake facilities, and the

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 ...

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

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

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.

Separation of Peptides with Forward Osmosis Biomimetic Membranes

OpenAIRE

Bajraktari, Niada; Madsen, Henrik T.; Gruber, Mathias F.; Truelsen, Sigurd; Jensen, Elzbieta L.; Jensen, Henrik; H?lix-Nielsen, Claus

2016-01-01

Forward osmosis (FO) membranes have gained interest in several disciplines for the rejection and concentration of various molecules. One application area for FO membranes that is becoming increasingly popular is the use of the membranes to concentrate or dilute high value compound solutions such as pharmaceuticals. It is crucial in such settings to control the transport over the membrane to avoid losses of valuable compounds, but little is known about the rejection and transport mechanisms of...

Testing of a benchscale Reverse Osmosis/Coupled Transport system for treating contaminated groundwater

International Nuclear Information System (INIS)

Hodgson, K.M.; Lunsford, T.R.; Panjabi, G.

1994-01-01

The Reverse Osmosis/Coupled Transport process is a innovative means of removing radionuclides from contaminated groundwater at the Hanford Site. Specifically, groundwater in the 200 West Area of the Hanford Site has been contaminated with uranium, technetium, and nitrate. Investigations are proceeding to determine the most cost effective method to remove these contaminants. The process described in this paper combines three different membrane technologies (reverse osmosis, coupled transport, and nanofiltration to purify the groundwater while extracting and concentrating uranium, technetium, and nitrate into separate solutions. This separation allows for the future use of the radionuclides, if needed, and reduces the amount of waste that will need to be disposed of. This process has the potential to concentrate the contaminants into solutions with volumes in a ratio of 1/10,000 of the feed volume. This compares to traditional volume reductions of 10 to 100 for ion exchange and stand-alone reverse osmosis. The successful demonstration of this technology could result in significant savings in the overall cost of decontaminating the groundwater

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}.

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…

Biofouling of reverse osmosis membranes: effects of cleaning on biofilm microbial communities, membrane performance, and adherence of extracellular polymeric substances.

Science.gov (United States)

Al Ashhab, Ashraf; Sweity, Amer; Bayramoglu, Bihter; Herzberg, Moshe; Gillor, Osnat

2017-05-01

Laboratory-scale reverse osmosis (RO) flat-sheet systems were used with two parallel flow cells, one treated with cleaning agents and a control (ie undisturbed). The cleaning efforts increased the affinity of extracellular polymeric substances (EPS) to the RO membrane and altered the biofilm surface structure. Analysis of the membrane biofilm community composition revealed the dominance of Proteobacteria. However, within the phylum Proteobacteria, γ-Proteobacteria dominated the cleaned membrane biofilm, while β-Proteobacteria dominated the control biofilm. The composition of the fungal phyla was also altered by cleaning, with enhancement of Ascomycota and suppression of Basidiomycota. The results suggest that repeated cleaning cycles select for microbial groups that strongly attach to the RO membrane surface by producing rigid and adhesive EPS that hampers membrane performance.

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.

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.

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

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

Studies on the reverse osmosis treatment of uranyl nitrate solution

International Nuclear Information System (INIS)

Prabhakar, S.; Panicker, S.T.; Misra, B.M.; Ramani, P.S.

1992-01-01

The aqueous effluent generated in uranium processing, particularly in the nuclear fuel fabrication step, contains mainly uranium nitrate. This requires treatment before discharge into the environment to meet stringent standards. This paper presents the performance of cellulose acetate membranes with regard to rejection of uranium under reverse osmotic conditions for feed concentrations up to 200 mg/l of uranium, which corresponds to the levels normally prevalent in the effluents. The use of additives like the disodium salt of ethylenediaminetetraacetic acid and sodium sulfate for the improvement of reverse osmosis performance of the above membranes was also investigated. In the light of the experimental results, the suitability of reverse osmosis for the decontamination of uranium effluents is discussed

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.

Post-Digestion Liquor Treatment in the Method Combining Chemical Precipitation with Reverse Osmosis

Directory of Open Access Journals (Sweden)

Kuglarz Mariusz

2014-12-01

Full Text Available The aim of the study was to develop an effective treatment of post-digestion liquors highly-loaded with biogenic and organic substances. The scope of the research project encompassed: mesophilic anaerobic digestion of waste activated sludge (WAS as well as the treatment of post-digestion liquors, coming from the most appropriate HRT value of 25 days, in the process of ammonium magnesium phosphate (struvite precipitation targeted at ammonia nitrogen binding and a subsequent reverse osmosis (RO process. It was established that the method combining chemical precipitation and high-pressure filtration ensures a high degree of contaminants removal allowing for a direct release of treated liquors into the natural reservoir. However, in order to decrease the residual NH4+ concentration (6.1 mg NH4+/dm3 in the purified post-digestion liquors below the level allowing for a direct release to the natural reservoir, it turned out to be necessary to apply increased molar ratio of magnesium and phosphates (Mg:NH4+: PO43-= 1.5:1:1.5.

Osmosis in groundwater : Chemical and electrical extensions to Darcy's Law

NARCIS (Netherlands)

Bader, S.

2005-01-01

In problems of groundwater flow and solute transport in clayey soils subject to salt concentration gradients, chemical and electro-osmosis can be too important to disregard, as is commonly done in geohydrology. In this thesis, we consider the quantification of these couple effects to be able to

Salinity-gradient power: Evaluation of pressure-retarded osmosis and reverse electrodialysis

NARCIS (Netherlands)

Post, J.W.; Veerman, J.; Hamelers, H.V.M.; Euverink, G.J.W.; Metz, S.J.; Nymeijer, K.; Buisman, C.J.N.

2007-01-01

A huge potential to obtain clean energy exists from mixing water streams with different salt concentrations. Two membrane-based energy conversion techniques are evaluated: pressure-retarded osmosis and reverse electrodialysis. From the literature, a comparison is not possible since the reported

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.

Flux patterns and membrane fouling propensity during desalination of seawater by forward osmosis

KAUST Repository

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

2012-01-01

The membrane fouling propensity of natural seawater during forward osmosis was studied. Seawater from the Red Sea was used as the feed in a forward osmosis process while a 2. M sodium chloride solution was used as the draw solution. The process was conducted in a semi-batch mode under two crossflow velocities, 16.7. cm/s and 4.2. cm/s. For the first time reported, silica scaling was found to be the dominant inorganic fouling (scaling) on the surface of membrane active layer during seawater forward osmosis. Polymerization of dissolved silica was the major mechanism for the formation of silica scaling. After ten batches of seawater forward osmosis, the membrane surface was covered by a fouling layer of assorted polymerized silica clusters and natural organic matter, especially biopolymers. Moreover, the absorbed biopolymers also provided bacterial attachment sites. The accumulated organic fouling could be partially removed by water flushing while the polymerized silica was difficult to remove. The rate of flux decline was about 53% with a crossflow velocity of 16.7. cm/s while reaching more than 70% with a crossflow velocity of 4.2. cm/s. Both concentration polarization and fouling played roles in the decrease of flux. The salt rejection was stable at about 98% during seawater forward osmosis. In addition, an almost complete rejection of natural organic matter was attained. The results from this study are valuable for the design and development of a successful protocol for a pretreatment process before seawater forward osmosis and a cleaning method for fouled membranes. © 2011 Elsevier Ltd.

Application of reverse osmosis in radioactive wastewater treatment

International Nuclear Information System (INIS)

Kong Jinsong; Guo Weiqun

2012-01-01

Considering the disadvantages of the conventional evaporation and ion exchange process for radioactive wastewater treatment, the reverse osmosis is used to treat the low level radioactive wastewater. The paper summarizes the research and application progress of the reverse osmosis in the radioactive wastewater treatment and indicates that the reverse osmosis in the radioactive wastewater treatment is very important. (authors)

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

Modeling pH variation in reverse osmosis.

Science.gov (United States)

Nir, Oded; Bishop, Noga Fridman; Lahav, Ori; Freger, Viatcheslav

2015-12-15

The transport of hydronium and hydroxide ions through reverse osmosis membranes constitutes a unique case of ionic species characterized by uncommonly high permeabilities. Combined with electromigration, this leads to complex behavior of permeate pH, e.g., negative rejection, as often observed for monovalent ions in nanofiltration of salt mixtures. In this work we employed a rigorous phenomenological approach combined with chemical equilibrium to describe the trans-membrane transport of hydronium and hydroxide ions along with salt transport and calculate the resulting permeate pH. Starting from the Nernst-Planck equation, a full non-linear transport equation was derived, for which an approximate solution was proposed based on the analytical solution previously developed for trace ions in a dominant salt. Using the developed approximate equation, transport coefficients were deduced from experimental results obtained using a spiral wound reverse osmosis module operated under varying permeate flux (2-11 μm/s), NaCl feed concentrations (0.04-0.18 M) and feed pH values (5.5-9.0). The approximate equation agreed well with the experimental results, corroborating the finding that diffusion and electromigration, rather than a priori neglected convection, were the major contributors to the transport of hydronium and hydroxide. The approach presented here has the potential to improve the predictive capacity of reverse osmosis transport models for acid-base species, thereby improving process design/control. Copyright © 2015 Elsevier Ltd. All rights reserved.

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...

Kinetic study of seawater reverse osmosis membrane fouling

KAUST Repository

Khan, Muhammad

2013-10-01

Reverse osmosis (RO) membrane fouling is not a static state but a dynamic phenomenon. The investigation of fouling kinetics and dynamics of change in the composition of the foulant mass is essential to elucidate the mechanism of fouling and foulant-foulant interactions. The aim of this work was to study at a lab scale the fouling process with an emphasis on the changes in the relative composition of foulant material as a function of operating time. Fouled membrane samples were collected at 8 h, and 1, 2, and 4 weeks on a lab-scale RO unit operated in recirculation mode. Foulant characterization was performed by CLSM, AFM, ATR-FTIR, pyrolysis GC-MS, and ICP-MS techniques. Moreover, measurement of active biomass and analysis of microbial diversity were performed by ATP analysis and DNA extraction, followed by pyro-sequencing, respectively. A progressive increase in the abundance of almost all the foulant species was observed, but their relative proportion changed over the age of the fouling layer. Microbial population in all the membrane samples was dominated by specific groups/species belonging to Proteobacteria and Actinobacteria phyla; however, similar to abiotic foulant, their relative abundance also changed with the biofilm age. © 2013 American Chemical Society.

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

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

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

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

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....

Experimental Study of Dye Removal from Industrial Wastewater by Membrane Technologies of Reverse Osmosis and Nanofiltration

Directory of Open Access Journals (Sweden)

Mohammad Fadhil Abid

2012-12-01

Full Text Available Currently, biological method has been utilized in the treatment of wastewater -containing synthetic dyes used by textile industries in Iraq. The present work was devoted to study the operating feasibility using reverse osmosis (RO and nanofiltration (NF membrane systems as an alternative treatment method of wastewater discharged from Iraqi textile mills. Acid red, reactive black and reactive blue dyes were selected, based on the usage rate in Iraq. Effects of dye concentration, pH of solution, feed temperature, dissolved salts and operating pressure on permeate flux and dye rejection were studied. Results at operating conditions of dye concentration?=?65 mg/L, feed temperature?=?39?C and pressure?=?8 bar showed the final dye removal with RO membrane as 97.2%, 99.58% and 99.9% for acid red, reactive black and reactive blue dyes, respectively. With NF membrane, the final dye removal were as 93.77%, 95.67%, and 97% for red, black and blue dyes, respectively. The presence of salt (particularly NaCl in the dye solution resulted in a higher color removal with a permeate flux decline. It was confirmed that pH of solution had a positive impact on dye removal while feed temperature showed a different image. A comparison was made between the results of dye removal in biological and membrane methods. The results showed that membrane method had higher removal potential with lower effective cost. The present study indicates that the use of NF membrane in dye removal from the effluent of Iraqi textile mills is promising.

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

Aerobic SMBR/reverse osmosis system enhanced by Fenton oxidation for advanced treatment of old municipal landfill leachate.

Science.gov (United States)

Zhang, Guoliang; Qin, Lei; Meng, Qin; Fan, Zheng; Wu, Dexin

2013-08-01

A novel combined process of Fenton oxidation, submerged membrane bioreactor (SMBR) and reverse osmosis (RO) was applied as an appropriate option for old municipal landfill leachate treatment. Fenton process was designed to intensively solve the problem of non-biodegradable organic pollutant removal and low biodegradability of leachate, although the removal of ammonia-nitrogen was similar to 10%. After SMBR treatment, it not only presented a higher removal efficiency of organics, but also exhibited high ammonia-nitrogen removal of 80% on average. The variation of extracellular polymeric substance (EPS) content, zeta potential, and particle size of flocs after Fenton effluent continually fed in SMBR was found to be benefit for alleviating membrane fouling. Finally, three kinds of RO membranes (RE, CPA, and BW) were applied to treat SMBR effluents and successfully met wastewater re-utilization requirement. Compared with simple RO process, the troublesome membrane fouling can be effectively reduced in the combined process. Copyright © 2013 Elsevier Ltd. All rights reserved.

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.)

Removal of oil pollutants in seawater as pretreatment of reverse osmosis desalination process

Energy Technology Data Exchange (ETDEWEB)

Wen Jian; Nishijima, Wataru; Baes, Aloysius U.; Okada, Mitsumasa [Hiroshima Univ., Environmental Science Dept., Hiroshima (Japan); Kitanaka, Atsushi [Fuji-Electric Corporate Research and Development Ltd., Yokosuka, Kanagawa (Japan)

1999-11-01

Weathered oil contaminated seawater (WOCS) was used to investigate the behaviour of soluble oil components in seawater in various pretreatment processes for removal of oil pollutants in seawater. The various pretreatment processes were a reverse osmosis desalination process in combination with advanced oxidation processes, ultrafiltration, coagulation, GAC adsorption, biological treatment and separation with a low pressure RO membrane. WOCS was prepared by mixing oil, nutrients and fresh seawater which was exposed to sunlight to simulate photooxidation and microbial degradation of oil in the marine environment. It was found that WOCS contained soluble components with relatively small molecular size, which are refractory to biodegradation and difficult to remove by advanced oxidation processes (AOPs), UF membrane or coagulation using FeCl{sub 3} or PAC as flocculants. However, DOC in WOCS (OCWOCS) was easily adsorbed to GAC. Low pressure RO membranes with higher salt rejection rate could remove more OCWOCS compared to those of lower salt rejection rate. (Author)

Removal of oil pollutants in seawater as pretreatment of reverse osmosis desalination process

Energy Technology Data Exchange (ETDEWEB)

Wen Jian; Nishijima, Wataru; Baes, Aloysius U.; Okada, Mitsumasa [Hiroshima Univ., Environmental Science Dept., Hiroshima (Japan); Kitanaka, Atsushi [Fuji-Electric Corporate Research and Development Ltd., Yokosuka, Kanagawa (Japan)

1999-07-01

Weathered oil contaminated seawater (WOCS) was used to investigate the behaviour of soluble oil components in seawater in various pretreatment processes for removal of oil pollutants in seawater. The various pretreatment processes were a reverse osmosis desalination process in combination with advanced oxidation processes, ultrafiltration, coagulation, GAC adsorption, biological treatment and separation with a low pressure RO membrane. WOCS was prepared by mixing oil, nutrients and fresh seawater which was exposed to sunlight to simulate photooxidation and microbial degradation of oil in the marine environment. It was found that WOCS contained soluble components with relatively small molecular size, which are refractory to biodegradation and difficult to remove by advanced oxidation processes (AOPs), UF membrane or coagulation using FeCl{sub 3} or PAC as flocculants. However, DOC in WOCS (OCWOCS) was easily adsorbed to GAC. Low pressure RO membranes with higher salt rejection rate could remove more OCWOCS compared to those of lower salt rejection rate. (Author)

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.

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.

Effect of pretreatment and membrane orientation on fluxes for concentration of whey with high foulants by using NH3/CO2 in forward osmosis.

Science.gov (United States)

Seker, M; Buyuksari, E; Topcu, S; Babaoglu, D S; Celebi, D; Keskinler, B; Aydiner, C

2017-11-01

Usage of forward osmosis membrane in FO mode, in which active and support layers of the membrane were in contact with the feed and the draw solutions respectively, provided higher initial water flux (12L/m 2 h) than the usage of membrane in PRO mode (6L/m 2 h) having opposite orientation but fluxes approached to each other after 4h during concentration of whey with NH 3 /CO 2 as draw salt. High organic and inorganic foulants of whey was considered as reason for observed result in addition to lower solute resistivity. Initial water flux (8,5L/m 2 h) was lower when pre-treatment was applied before forward osmosis process but final flux (4L/m 2 h) was equal flux of non pre-treatment. Reduction of solute resistivity or absence of hydraulic pressure can be reasons for lower initial flux. Detection of organic carbon but absence of lactose in draw solution showed passage of molecules being different than lactose into draw solution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electrochemical treatment of reverse osmosis concentrate on boron-doped electrodes in undivided and divided cell configurations.

Science.gov (United States)

Bagastyo, Arseto Y; Batstone, Damien J; Kristiana, Ina; Escher, Beate I; Joll, Cynthia; Radjenovic, Jelena

2014-08-30

An undivided electrolytic cell may offer lower electrochlorination through reduction of chlorine/hypochlorite at the cathode. This study investigated the performance of electrooxidation of reverse osmosis concentrate using boron-doped diamond electrodes in membrane-divided and undivided cells. In both cell configurations, similar extents of chemical oxygen demand and dissolved organic carbon removal were obtained. Continuous formation of chlorinated organic compounds was observed regardless of the membrane presence. However, halogenation of the organic matter did not result in a corresponding increase in toxicity (Vibrio fischeri bioassay performed on extracted samples), with toxicity decreasing slightly until 10AhL(-1), and generally remaining near the initial baseline-toxicity equivalent concentration (TEQ) of the raw concentrate (i.e., ∼2mgL(-1)). The exception was a high range toxicity measure in the undivided cell (i.e., TEQ=11mgL(-1) at 2.4AhL(-1)), which rapidly decreased to 4mgL(-1). The discrepancy between the halogenated organic matter and toxicity patterns may be a consequence of volatile and/or polar halogenated by-products formed in oxidation by OH electrogenerated at the anode. The undivided cell exhibited lower energy compared to the divided cell, 0.25kWhgCOD(-1) and 0.34kWhgCOD(-1), respectively, yet it did not demonstrate any improvement regarding by-products formation. Copyright © 2014 Elsevier B.V. All rights reserved.

Ion-containing reverse osmosis membranes obtained by radiation grafting method

International Nuclear Information System (INIS)

Hegazy, E.-S.A.; El-Assy, N.B.; Dessouki, A.M.; Shaker, M.M.

1989-01-01

Cationic membranes obtained by radiation grafting of aqueous acrylic acid onto low density polyethylene films followed by alkaline treatment to confer ionic character in the graft chains, were tested for reverse osmosis desalination of saline water. Selected physical properties of such membranes were investigated. The grafted membranes possess good mechanical and electrical properties. Water uptake for the alkali-treated membrane was much higher than that of the alkali-untreated one. The effect of operation time, degree of grafting, applied pressure and feed concentration on the water flux and salt rejection for the grafted membranes was investigated. Such cationic membranes showed good durability, thermal and chemical stability, acceptable water flux and salt rejection which may make them acceptable for practical use in reverse osmosis desalination of sea water. (author)

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)

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.

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.

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

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.

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.

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.

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

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.

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.

Method for the disposal of laundry drain by inverse osmosis method

International Nuclear Information System (INIS)

Sugimoto, Yoshikazu; Yusa, Hideo; Kamiya, Kunio; Ebara, Katsuya.

1976-01-01

Purpose: To effectively obtain clean water of high purity from laundry waste from work clothes or the like worn in the atomic power plant and to increase the concentration factor of the impurities. Constitution: The laundry drain is supplied to a forestage condensation tank through a supply pipe, via a control valve controlled by a level gage so as to always maintain the liquid level constant, and the liquid within the tank is increased in pressure by the fore-stage high pressure pump and supplied to the fore-stage inverse osmosis module. There occurs a phenomenon of inverse osmosis so that water in disposed liquid is urged through a film and discharged from a osmosed water discharge pipe. In this case, the concentration of a surface active agent in the disposed liquid is detected by a flow meter depending on the quantity of osmosed water, and when the concentration exceeds a predetermined level to decrease the quantity of osmosed water, the opening of the control valve is increased and the liquid is discharged from the discharge pipe into the final tank for disposal in substantially similar manner. (Yoshihara, H.)

Chlorine-Resistant Polyamide Reverse Osmosis Membrane with Monitorable and Regenerative Sacrificial Layers.

Science.gov (United States)

Huang, Hai; Lin, Saisai; Zhang, Lin; Hou, Li'an

2017-03-22

Improving chlorine stability is a high priority for aromatic polyamide (PA) reverse osmosis (RO) membranes especially in long-term desalination. In this Research Article, PA RO membranes of sustainable chlorine resistance was synthesized. Glycylglycine (Gly) was grafted onto the membrane surface as a regenerative chlorine sacrificial layer, and the zeta-potential was used to monitor the membrane performance and to conduct timely regeneration operations for chlorinated Gly. The Gly-grafted PA membrane exhibited ameliorative chlorine resistance in which the N-H moiety of glycylglycine served as sacrificial pendants against chlorine attacks. Cyclic chlorination experiments, combined with FT-IR and XPS analysis, were carried out to characterize the membrane. Results indicated that the resulting N-halamines could be fast regenerated by a simple alkaline reduction step (pH 10). A synchronous relationship between the zeta-potential and the chlorination extent of the sacrificial layer was observed. This indicated that the zeta-potential can be used as an on-site sensor to conduct a timely regeneration operation. The intrinsic mechanism of the surface sacrificial process was also studied.

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.

The effects of physicochemical wastewater treatment operations on forward osmosis

OpenAIRE

Hey, Tobias; Bajraktari, Niada; Vogel, Jörg; Hélix-Nielsen, Claus; La Cour Jansen, Jes; Jönsson, Karin

2016-01-01

Raw municipal wastewater from a full-scale wastewater treatment plant was physicochemically pretreated in a large pilot-scale system comprising coagulation, flocculation, microsieve and microfiltration operated in various configurations. The produced microsieve filtrates and microfiltration permeates were then concentrated using forward osmosis (FO). Aquaporin Inside(TM) FO membranes were used for both the microsieve filtrate and microfiltration permeates, and Hydration Technologies Inc.-thin...

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

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.

Reverse osmosis influence over the content of metals and organic acids in low alcoholic beverages

Directory of Open Access Journals (Sweden)

Andrieş Mitică Tiberiu

2017-01-01

Full Text Available Wine is defined as an alcoholic beverage resulted from fermentation of grape must, having ethanol content higher than 8.5% (v/v. Wine consumption has health benefits related to the high concentration of polyphenolic compounds with antioxidant activity and cardiovascular protection effects. However, the alcohol content restricts wine consumption, but wines with low-alcohol content can be obtained with the help of the dealcoholisation process, after it was produced through alcoholic fermentation. The purpose of this work is to evaluate the organic acid concentration, metal content and other physical-chemical parameters of low alcoholic beverages obtained from grape must by a process which involves reverse osmosis, mixing in a variable ratio the permeate and concentrate and then fermentation. For the experiments, a Muscat Ottonel grape must from Iaşi vineyard was used. There were ten variants of beverages (wines with low alcoholic concentration, by mixing known quantities of the two phases resulting from the reverse osmosis process. These beverages (wines had an alcoholic concentration starting from 2.5% (v/v in the first variant, up to 7% (v/v in the tenth variant. Alcoholic concentration varies for each variant by 0.5% (v/v. After fermentation in 50 L stainless steel tanks, the samples were filtered with 0.45μm sterile membrane and bottled in 0.75 L glass bottles. After 2 months of storage at constant temperature, the beverage samples were analyzed to determine the metal content (AAS method, organic acids concentration (HPLC method, and other physical-chemical characteristics (OIV standard methods. The results obtained indicate that the very complex physical-chemical composition of the low alcoholic beverages analyzed is influenced by the specific chemical composition of a given grape must, as well as by the use of products obtained from reverse osmosis.

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

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)

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.

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.

Validation and analysis of forward osmosis CFD model in complex 3D geometries

DEFF Research Database (Denmark)

Gruber, Mathias F.; Gruber, Mathias F.; Johnson, Carl J.

2012-01-01

In forward osmosis (FO), an osmotic pressure gradient generated across a semi-permeable membrane is used to generate water transport from a dilute feed solution into a concentrated draw solution. This principle has shown great promise in the areas of water purification, wastewater treatment...

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.

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.

Performance evaluation of reverse osmosis technology for selected antibiotics removal from synthetic pharmaceutical wastewater

Directory of Open Access Journals (Sweden)

Gholami Mitra

2012-12-01

Full Text Available Abstract This study addresses the possibility for low pressure reverse osmosis membrane (RE 2521, CSM process to serve as an alternative to remove selected antibiotics (ampicillin and amoxicillin from synthetic wastewater by changing operating conditions such as pH = 3, 6.5 and 10; Pressure = 9, 11 and13 (bar; antibiotic concentration = 10, 255 and 500(mg/L, and temperature = 20, 30 and 40°C. The experiment was designed based on Box-benken, which is a Response Surface methodology design (RSM, using Design Expert software. The concentration of antibiotics was measured by applying a UV-spectrophotometer (Cecil, at the wavelength of 254 nm. Results showed a range of rejection percentage from 73.52% to 99.36% and 75.1% to 98.8%, for amoxicillin and ampicillin, respectively. Considering the solute rejections and the membrane porosity show that the prevailing rejection mechanism of the examined antibiotics by the membrane was the size exclusion effect. The permeate flux for both of the antibiotics was 12–18.73 L/m2.h. Although the permeate flux and antibiotic rejection are influenced by operating pressure, pH, and temperature individually, the interaction between operating parameters did not have noticeable effects. According to the results obtained in this study, the application of RO membrane is recommended for the selected antibiotics to be removed to a considerable degree (up to 95%.

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.

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)

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 ...

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.

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.

-permeability plastic formation such as the Boom Clay. The osmotic efficiency of Boom Clay is high under undisturbed chemical conditions ( σ = 0.41 at 0.014 M NaHCO 3), but rapidly decreases when the dissolved salts concentration increases ( σ = 0.07 at 0.14 M NaHCO 3). A semi-permeable membrane behaviour of the Boom Clay (high efficiencies) may be expected for the disposal of nitrate-bearing radioactive waste. However, the presently observed osmotically induced pressure is too low to have a significant mechanical impact on the host rock. Finally, the short duration of the osmosis test performed suggests that the shut-in test method used is effective for osmosis testing.

Processing radioactive wastes using membrane (UF/HF/RO) systems

International Nuclear Information System (INIS)

Doyle, R.D.

1988-01-01

Over the years many technologies have been utilized to process low level radioactive waste streams generated by the nuclear industry, including: demineralization, evaporation, reverse osmosis and filtration. In the early 1980's interest was generated in membrane technologies and their application to radioactive wastes. This interest was generated based on the capabilities shown by membrane systems in non-radioactive environments and the promise that reverse osmosis systems showed in early testing with radioactive wastes. Membrane technologies have developed from the early development of reverse osmosis system to also include specifically designed membranes for ultrafiltration and hyperfiltration applications

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.

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

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

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

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.

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.

An integrated mechanical-enzymatic reverse osmosis treatment of dairy industry wastewater and milk protein recovery as a fat replacer: a closed loop approach

Directory of Open Access Journals (Sweden)

F. Sarghini

2013-09-01

Full Text Available The dairy industry can be classified among the most polluting of the food industries in volume in regard to its large water consumption, generating from 0.2 to 10 L of effluent per liter of processed milk. Dairy industry effluents usually include highly dissolved organic matter with varying characteristics, and a correct waste management project is required to handle. In a framework of natural water resource availability and cost increase, wastewater treatment for water reuse can lower the overall water consumption and the global effluent volume of industrial plants. Moreover, correct dismissal of dairy industry wastewater is sometimes neglected by the operators , increasing the environmental impact due to the chemical and biological characteristics of such effluents. On the other hand, in the case of whey effluents, several by-products are still present inside, such as lactose and milk proteins. Membrane technology has some advantages including a high degree of reliability in removing dissolved, colloidal and particulate matter, like the selectivity in size of pollutants to be removed and the possibility of very compact treatment plants. For example, Reverse Osmosis (RO technology has been successfully applied for the treatment of dairy wastes (1, and as a technology for concentration and fractionation of whey. In this work a membrane treatment approach using reverse osmosis technology is investigated and implemented: the permeate obtained can be reused as clean warm water for cleaning and sanitation of production plants, while concentrated milk proteins are modified by using transglutaminase enzyme obtaining a high temperature resistant fat replacer to be used in different low-fat products like for example mozzarella cheese.

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.

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.

Concentrations and distributions of metals associated with dissolved organic matter from the Suwannee River (GA, USA)

Science.gov (United States)

Kuhn, M. Keshia; Neubauer, Elisabeth; Hofmann, Thilo; von der Kammer, Frank; Aiken, George R.; Maurice, Patricia A.

2015-01-01

Concentrations and distributions of metals in Suwannee River (SR) raw filtered surface water (RFSW) and dissolved organic matter (DOM) processed by reverse osmosis (RO), XAD-8 resin (for humic and fulvic acids [FA]), and XAD-4 resin (for “transphilic” acids) were analyzed by asymmetrical flow field-flow fractionation (AsFlFFF). SR samples were compared with DOM samples from Nelson's Creek (NLC), a wetland-draining stream in northern Michigan; previous International Humic Substances Society (IHSS) FA and RO samples from the SR; and an XAD-8 sample from Lake Fryxell (LF), Antarctica. Despite application of cation exchange during sample processing, all XAD and RO samples contained substantial metal concentrations. AsFlFFF fractograms allowed metal distributions to be characterized as a function of DOM component molecular weight (MW). In SR RFSW, Fe, Al, and Cu were primarily associated with intermediate to higher than average MW DOM components. SR RO, XAD-8, and XAD-4 samples from May 2012 showed similar MW trends for Fe and Al but Cu tended to associate more with lower MW DOM. LF DOM had abundant Cu and Zn, perhaps due to amine groups that should be present due to its primarily algal origins. None of the fractograms showed obvious evidence for mineral nanoparticles, although some very small mineral nanoparticles might have been present at trace concentrations. This research suggests that AsFlFFF is important for understanding how metals are distributed in different DOM samples (including IHSS samples), which may be key to metal reactivity and bioavailability.

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.

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

Nonlinear Diffusion and Transient Osmosis

International Nuclear Information System (INIS)

Igarashi, Akira; Rondoni, Lamberto; Botrugno, Antonio; Pizzi, Marco

2011-01-01

We investigate both analytically and numerically the concentration dynamics of a solution in two containers connected by a narrow and short channel, in which diffusion obeys a porous medium equation. We also consider the variation of the pressure in the containers due to the flow of matter in the channel. In particular, we identify a phenomenon, which depends on the transport of matter across nano-porous membranes, which we call ''transient osmosis . We find that nonlinear diffusion of the porous medium equation type allows numerous different osmotic-like phenomena, which are not present in the case of ordinary Fickian diffusion. Experimental results suggest one possible candidate for transiently osmotic processes. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

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.

Identification of some factors affecting pharmaceutical active compounds (PhACs) removal in real wastewater. Case study of fungal treatment of reverse osmosis concentrate.

Science.gov (United States)

Badia-Fabregat, Marina; Lucas, Daniel; Gros, Meritxell; Rodríguez-Mozaz, Sara; Barceló, Damià; Caminal, Glòria; Vicent, Teresa

2015-01-01

Many technologies are being developed for the efficient removal of micropollutants from wastewater and, among them, fungal degradation is one of the possible alternative biological treatments. In this article, some factors that might affect pharmaceutically active compounds (PhACs) removal in a fungal treatment of real wastewater were identified in batch bioreactor treating reverse osmosis concentrate (ROC) from urban wastewater treatment plant (WWTP). We found that degradation of PhACs by Trametes versicolor was enhanced by addition of external nutrients (global removal of 44%). Moreover, our results point out that high aeration might be involved in the increase in the concentration of some PhACs. In fact, conjugation and deconjugation processes (among others) affect the removal assessment of emerging contaminants when working with real concentrations in comparison to experiments with spiked samples. Moreover, factors that could affect the quantification of micropollutants at lab-scale experiments were studied. Copyright © 2014 Elsevier B.V. All rights reserved.

Reverse osmosis performance of cellulose acetate membranes in the separation of uranium from dilute solutions

International Nuclear Information System (INIS)

Sastri, V.S.; Ashbrook, A.W.

1976-01-01

Batch 316-type cellulose acetate membranes were characterized in terms of pure water permeability constant, solute transport parameter, and mass transfer coefficient with a reference system of aqueous sodium chloride solution. These membranes were used in the determination of reverse osmosis characteristics such as product rate and solute separation in the case of uranium sulfate solutions of different concentrations (100 to 8000 ppM) in the feed solutions. A long-term test extending over a week has been carried out with dilute uranium solutions. Reverse osmosis treatment of synthetic mine water sample showed satisfactory performance of the membranes in the separation of metal ions

Effect of engineered environment on microbial community structure in biofilter and biofilm on reverse osmosis membrane.

Science.gov (United States)

Jeong, Sanghyun; Cho, Kyungjin; Jeong, Dawoon; Lee, Seockheon; Leiknes, TorOve; Vigneswaran, Saravanamuthu; Bae, Hyokwan

2017-11-01

Four dual media filters (DMFs) were operated in a biofiltration mode with different engineered environments (DMF I and II: coagulation with/without acidification and DMF III and IV: without/with chlorination). Designed biofilm enrichment reactors (BERs) containing the removable reverse osmosis (RO) coupons, were connected at the end of the DMFs in parallel to analyze the biofilm on the RO membrane by DMF effluents. Filtration performances were evaluated in terms of dissolved organic carbon (DOC) and assimilable organic carbon (AOC). Organic foulants on the RO membrane were also quantified and fractionized. The bacterial community structures in liquid (seawater and effluent) and biofilm (DMF and RO) samples were analyzed using 454-pyrosequencing. The DMF IV fed with the chlorinated seawater demonstrated the highest reductions of DOC including LMW-N as well as AOC among the other DMFs. The DMF IV was also effective in reducing organic foulants on the RO membrane surface. The bacterial community structure was grouped according to the sample phase (i.e., liquid and biofilm samples), sampling location (i.e., DMF and RO samples), and chlorination (chlorinated and non-chlorinated samples). In particular, the biofilm community in the DMF IV differed from the other DMF treatments, suggesting that chlorination exerted as stronger selective pressure than pH adjustment or coagulation on the biofilm community. In the DMF IV, several chemoorganotrophic chlorine-resistant biofilm-forming bacteria such as Hyphomonas, Erythrobacter, and Sphingomonas were predominant, and they may enhance organic carbon degradation efficiency. Diverse halophilic or halotolerant organic degraders were also found in other DMFs (i.e., DMF I, II, and III). Various kinds of dominant biofilm-forming bacteria were also investigated in RO membrane samples; the results provided possible candidates that cause biofouling when DMF process is applied as the pretreatment option for the RO process. Copyright �

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.

Effect of engineered environment on microbial community structure in biofilter and biofilm on reverse osmosis membrane

KAUST Repository

Jeong, Sanghyun

2017-07-25

Four dual media filters (DMFs) were operated in a biofiltration mode with different engineered environments (DMF I and II: coagulation with/without acidification and DMF III and IV: without/with chlorination). Designed biofilm enrichment reactors (BERs) containing the removable reverse osmosis (RO) coupons, were connected at the end of the DMFs in parallel to analyze the biofilm on the RO membrane by DMF effluents. Filtration performances were evaluated in terms of dissolved organic carbon (DOC) and assimilable organic carbon (AOC). Organic foulants on the RO membrane were also quantified and fractionized. The bacterial community structures in liquid (seawater and effluent) and biofilm (DMF and RO) samples were analyzed using 454-pyrosequencing. The DMF IV fed with the chlorinated seawater demonstrated the highest reductions of DOC including LMW-N as well as AOC among the other DMFs. The DMF IV was also effective in reducing organic foulants on the RO membrane surface. The bacterial community structure was grouped according to the sample phase (i.e., liquid and biofilm samples), sampling location (i.e., DMF and RO samples), and chlorination (chlorinated and non-chlorinated samples). In particular, the biofilm community in the DMF IV differed from the other DMF treatments, suggesting that chlorination exerted as stronger selective pressure than pH adjustment or coagulation on the biofilm community. In the DMF IV, several chemoorganotrophic chlorine-resistant biofilm-forming bacteria such as Hyphomonas, Erythrobacter, and Sphingomonas were predominant, and they may enhance organic carbon degradation efficiency. Diverse halophilic or halotolerant organic degraders were also found in other DMFs (i.e., DMF I, II, and III). Various kinds of dominant biofilm-forming bacteria were also investigated in RO membrane samples; the results provided possible candidates that cause biofouling when DMF process is applied as the pretreatment option for the RO process.

Liquid radwaste treatment by microfiltration, ultrafiltration and reverse osmosis

International Nuclear Information System (INIS)

Dulama, M.; Deneanu, N.; Popescu, I.V.

2001-01-01

Radioactive liquid waste processing is an integral part of any facility involved in nuclear power generation, radioisotope production, research and development, decontamination or other aspects of nuclear energy. The aqueous liquid radwastes from the decontamination center are currently treated by the membrane plant. Generally, the liquid waste streams are effectively volume-reduced by a combination of continuous crossflow microfiltration (MF), spiral wound reverse osmosis (SWRO) and tubular reverse osmosis membrane technologies. Backwash chemical cleaning wastes from the membrane plant are further volume-reduced by evaporation. The concentrate from the membrane plant is ultimately immobilized with bitumen. We performed experiments using two simulated waste solution; secondary waste from the decontamination process with POD (Permanganate Oxidation Decontamination) solution and secondary waste from decontamination with CAN-DECON solution. The experimental tests have been done with cellulose acetate (CA) membrane and polysulfonate (PSF) membrane manufactured at Research Center for Macromolecular Materials and Membranes Bucharest and with Millipore membrane type VS 0.025 μm. A schematic of the laboratory-scale test facility is presented

Cobalt and organics removal effect using fiber filter/reverse osmosis combination process for LLRW from korean PWR NPP

International Nuclear Information System (INIS)

Park, S.M.; Yang, H.Y.; Song, M.J.

2001-01-01

Evaporation system for liquid radioactive waste process has been used in Korean PWR nuclear power plants. The system is the most desirable process for decontamination factor (DF) theoretically. However, during the operation of the system, various problems have been arising such as scaling, carry over, etc. Because these problems make DF low, advanced technologies for liquid radwaste process have been world widely developed instead of keeping evaporation system. The main goal of new technologies is ALARA, ease of operation, cost effectiveness and minimization of environmental effect. Korea Electric Power Corporation is currently developing a combined treatment process for liquid radwaste using Micro-filter, Ultra-filter, Reverse Osmosis (RO) membrane, etc for the purpose of partly enhancement of evaporator and of having an alternative liquid radwaste process system for new reactors. As a part of the above project, the feasibility study using the Rolled Fiber-Filter (RFF) and RO membrane has been carried out. This paper reports the results of lab-test from the combined process of the fiber filtration and RO membrane module for cobalt and organics removal. The study was especially focused on the boric acid permeation in the RO unit. Because boric acid occupies large volume of the final waste after evaporation process, the new technology such as RO process has to be studied on the boron process. (author)

Electrochemical treatment of reverse osmosis concentrate on boron-doped electrodes in undivided and divided cell configurations

Energy Technology Data Exchange (ETDEWEB)

Bagastyo, Arseto Y. [Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072 (Australia); Department of Environmental Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111 (Indonesia); Batstone, Damien J. [Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072 (Australia); Kristiana, Ina [Curtin Water Quality Research Centre, Resources and Chemistry Precinct, Department of Chemistry, Curtin University, Bentley, Perth, WA 6102 (Australia); Escher, Beate I. [National Research Centre for Environmental Toxicology (Entox), The University of Queensland, Brisbane, QLD 4108 (Australia); Joll, Cynthia [Curtin Water Quality Research Centre, Resources and Chemistry Precinct, Department of Chemistry, Curtin University, Bentley, Perth, WA 6102 (Australia); Radjenovic, Jelena, E-mail: j.radjenovic@uq.edu.au [Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072 (Australia)

2014-08-30

Highlights: • 100% of COD and ∼70% of DOC was removed in both cell configurations. • ∼21.7 mg L{sup −1} of AOCl and ∼2.3 mg L{sup −1} of AOBr was formed regardless of the membrane use. • The TEQ was far lower than expected given the high AOCl concentrations. • The undivided cell consumed lower energy compared to the divided cell. - Abstract: An undivided electrolytic cell may offer lower electrochlorination through reduction of chlorine/hypochlorite at the cathode. This study investigated the performance of electrooxidation of reverse osmosis concentrate using boron-doped diamond electrodes in membrane-divided and undivided cells. In both cell configurations, similar extents of chemical oxygen demand and dissolved organic carbon removal were obtained. Continuous formation of chlorinated organic compounds was observed regardless of the membrane presence. However, halogenation of the organic matter did not result in a corresponding increase in toxicity (Vibrio fischeri bioassay performed on extracted samples), with toxicity decreasing slightly until 10 Ah L{sup −1}, and generally remaining near the initial baseline-toxicity equivalent concentration (TEQ) of the raw concentrate (i.e., ∼2 mg L{sup −1}). The exception was a high range toxicity measure in the undivided cell (i.e., TEQ = 11 mg L{sup −1} at 2.4 Ah L{sup −1}), which rapidly decreased to 4 mg L{sup −1}. The discrepancy between the halogenated organic matter and toxicity patterns may be a consequence of volatile and/or polar halogenated by-products formed in oxidation by OH· electrogenerated at the anode. The undivided cell exhibited lower energy compared to the divided cell, 0.25 kWh gCOD{sup −1} and 0.34 kWh gCOD{sup −1}, respectively, yet it did not demonstrate any improvement regarding by-products formation.

Tekanan Osmosis Membran Eritrosit Sapi Bali Jantan

Directory of Open Access Journals (Sweden)

Ardi Apriandi

2015-01-01

Full Text Available Tujuan penelitian untuk mengetahui Tekanan Osmosis Membran Eritrosit Sapi Bali Jantan. Materi yang digunakan yaitu 30 ekor sapi dewasa ( kondisi klinis sehat, tanpa memperhatikan asal, dan pakan yang diberikan yang disembelih di Rumah Pemotongan Hewan Pesanggaran, Denpasar. Metode penentuan tekanan osmosis yang dipakai menggunakan metode Swenson (2005, 2 mL darah sapi (diambil dari vena jugularis/saat disembelih, ditaruh dalam tabung reaksi yang telah diisi antikoagulan EDTA (Ethilyne Diamine Tetra Acetic. Kemudian disimpan dalam termos dingin dan segera diuji di laboratorium. Hasil menunjukkan bahwa tekanan osmosis membran eritrosit darah sapi bali sebagai berikut : hemolisis awal terjadi pada rata-rata 0,94 Osm/L (± 0.06 dengan rentang 0,85 Osm/L–1,03 Osm/L. Rataan total hemolisis 0,51 Osm/L (± 0,037 dengan rentang 0,51 Osm/L-0,60 Osm/L.

Combination of cupric ion with hydroxylamine and hydrogen peroxide for the control of bacterial biofilms on RO membranes.

Science.gov (United States)

Lee, Hye-Jin; Kim, Hyung-Eun; Lee, Changha

2017-03-01

Combinations of Cu(II) with hydroxylamine (HA) and hydrogen peroxide (H 2 O 2 ) (i.e., Cu(II)/HA, Cu(II)/H 2 O 2 , and Cu(II)/HA/H 2 O 2 systems) were investigated for the control of P. aeruginosa biofilms on reverse osmosis (RO) membranes. These Cu(II)-based disinfection systems effectively inactivated P. aeruginosa cells, exhibiting different behaviors depending on the state of bacterial cells (planktonic or biofilm) and the condition of biofilm growth and treatment (normal or pressurized condition). The Cu(II)/HA and Cu(II)/HA/H 2 O 2 systems were the most effective reagents for the inactivation of planktonic cells. However, these systems were not effective in inactivating cells in biofilms on the RO membranes possibly due to the interactions of Cu(I) with extracellular polymeric substances (EPS), where biofilms were grown and treated in center for disease control (CDC) reactors. Different from the results using CDC reactors, in a pressurized cross-flow RO filtration unit, the Cu(II)/HA/H 2 O 2 treatment significantly inactivated biofilm cells formed on the RO membranes, successfully recovering the permeate flux reduced by the biofouling. The pretreatment of feed solutions by Cu(II)/HA and Cu(II)/HA/H 2 O 2 systems (applied before the biofilm formation) effectively mitigated the permeate flux decline by preventing the biofilm growth on the RO membranes. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

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.

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.

Model-based performance and energy analyses of reverse osmosis to reuse wastewater in a PVC production site.

Science.gov (United States)

Hu, Kang; Fiedler, Thorsten; Blanco, Laura; Geissen, Sven-Uwe; Zander, Simon; Prieto, David; Blanco, Angeles; Negro, Carlos; Swinnen, Nathalie

2017-11-10

A pilot-scale reverse osmosis (RO) followed behind a membrane bioreactor (MBR) was developed for the desalination to reuse wastewater in a PVC production site. The solution-diffusion-film model (SDFM) based on the solution-diffusion model (SDM) and the film theory was proposed to describe rejections of electrolyte mixtures in the MBR effluent which consists of dominant ions (Na + and Cl - ) and several trace ions (Ca 2+ , Mg 2+ , K + and SO 4 2- ). The universal global optimisation method was used to estimate the ion permeability coefficients (B) and mass transfer coefficients (K) in SDFM. Then, the membrane performance was evaluated based on the estimated parameters which demonstrated that the theoretical simulations were in line with the experimental results for the dominant ions. Moreover, an energy analysis model with the consideration of limitation imposed by the thermodynamic restriction was proposed to analyse the specific energy consumption of the pilot-scale RO system in various scenarios.

Evaluation of spiral wound reverse osmosis for four radioactive waste processing applications

International Nuclear Information System (INIS)

Sen Gupta, S.K.

1997-01-01

A pilot-scale spiral wound reverse osmosis rig was used to treat four significantly different radioactive waste streams, three of which were generated at the Chalk River Laboratories at AECL. These streams included: 1. A chemical decontamination (CD/DC) waste stream which is routinely treated by the plant-scale membrane system at CRL; 2. Reactor waste which is a dilute radioactive waste stream (containing primarily tritium and organic acids), and it an effluent from the operating reactors at AECL; 3. An ion exchange regenerant waste stream which contains a mixture of stream (1) (CD/DC), blended with secondary waste from ion exchange regeneration; 4. Boric acid simulated waste which is a by-product waste of the PWR reactors. This was the only stream treated that was not generated as a waste liquid at AECL. For the first three streams specified above, reverse osmosis was used to remove chemical and radiochemical impurities from the water with efficiencies usually exceeding 99%. In these three cases the 'permeate' or clean water was the product of the process. In the case of stream 4, reverse osmosis was used in a recovery application for the purpose of recycling boric acid back to the reactor, with the concentrate being the 'product'. Reverse osmosis technology was successfully demonstrated for the treatment of all four streams. Prefiltration and oxidation (with photocatalytic continuous oxidation technology) were evaluated as pretreatment alternatives for streams 1, 2, and 3. The results indicated that the effective crossflow velocity through and membrane vessel was more important in determining the extent of membrane fouling than the specific pretreatment strategy employed. (author)

Short communication: The influence of solids concentration and bleaching agent on bleaching efficacy and flavor of sweet whey powder.

Science.gov (United States)

Jervis, M G; Smith, T J; Drake, M A

2015-04-01

Recent studies have demonstrated the effect of bleaching conditions and bleaching agent on flavor and functional properties of whey protein ingredients. Solids concentration at bleaching significantly affected bleaching efficacy and flavor effects of different bleaching agents. It is not known if these parameters influence quality of sweet whey powder (SWP). The purpose of this study was to determine the effects of solids concentration and bleaching agent on the flavor and bleaching efficacy of SWP. Colored cheddar whey was manufactured, fat separated, and pasteurized. Subsequently, the whey (6.7% solids) was bleached, concentrated using reverse osmosis (RO) to 14% solids, and then spray dried, or whey was concentrated before bleaching and then spray dried. Bleaching treatments included a control (no bleaching, 50 °C, 60 min), hydrogen peroxide (HP; 250 mg/kg, 50 °C, 60 min), benzoyl peroxide (50 mg/kg, 50 °C, 60 min), lactoperoxidase (20 mg/kg of HP, 50 °C, 30 min), and external peroxidase (MaxiBright, DSM Food Specialties, Delft, the Netherlands; 2 dairy bleaching units/mL, 50 °C, 30 min). The experiment was repeated in triplicate. Sensory properties and volatile compounds of SWP were evaluated by a trained panel and gas chromatography-mass spectrometry, respectively. Bleaching efficacy (norbixin destruction) and benzoic acid were measured by HPLC. Differences in bleaching efficacy, sensory and volatile compound profiles, and benzoic acid were observed with different bleaching agents, consistent with previous studies. Solids concentration affected bleaching efficacy of HP, but not other bleaching agents. The SWP from whey bleached with HP or lactoperoxidase following RO had increased cardboard and fatty flavors and higher concentrations of lipid oxidation compounds compared with SWP from whey bleached before RO. The SWP bleached with benzoyl peroxide after RO contained less benzoic acid than SWP from whey bleached before RO. These results indicate that

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.

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.

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.

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

The reversible N-oxidation of the nitroimidazole radiosensitizer Ro 03-8799

International Nuclear Information System (INIS)

Walton, M.I.; Bleehen, N.M.; Workman, P.; Cambridge Univ.

1985-01-01

The nitroimidazole radiosensitizer Ro 03-8799 and the N-oxide Ro 31-0313 were dissolved in buffered solution and given i.v. to inbred male mice. Drug concentrations in whole blood, blood plasma and urine were determined by MPLC. Ro 03 8799 is rapidly cleared and extensively metabolised. Ro 31-0313 is reduced back to Ro 03-8799 by whole blood. The pharmacological and toxicological consequences of this are unknown. (UK)

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.

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.

Capacity Analysis of Ro-Ro Terminals by Using Simulation Modeling Method

Directory of Open Access Journals (Sweden)

Emin Deniz Özkan

2016-09-01

Full Text Available In Ro-Ro terminals, terminal capacity is more needed than other types of marine terminals since Ro-Ro cargoes cannot be stacked. In this sense, the variables affecting capacity of a Ro-Ro terminal can be listed as follows; number of vehicles arrived to a terminal, distance between terminals, ship capacity, terminal gates, customs control units, terminal traffic and local traffic, security check, bunkering services etc. In this study, a model generated intended for making capacity analysis in Ro-Ro terminals by using simulation modeling method. Effect of three variables to terminal capacity was investigated while generating the scenarios; ‘number of trucks arriving to terminals’, ‘distance between terminals’ and ‘Ro-Ro ship capacity’. The results show that the variable which affect terminal capacity mostly is ‘number of trucks arriving to terminals’. As a consequence of this situation, it is thought that a Ro-Ro terminal operator must prioritize the demand factor and make an effective demand forecasting in determination of the terminal area.

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.

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.

Flow cytometric assessment of microbial abundance in the near-field area of seawater reverse osmosis concentrate discharge

KAUST Repository

Van Der Merwe, Riaan

2014-06-01

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 are the increase in salt concentration in receiving waters, which results in a density increase and potential water stratification near the outfall, and possible increases in turbidity, e.g., due to the discharge of filter backwash waters. Changes in ambient water quality may affect microbial abundance in the area, for example by hindering the photosynthesis process or disrupting biogenesis. It is widely accepted that marine biodiversity is lower in more extreme conditions, such as high salinity environments. As aquatic microbial communities respond very rapidly to changes in their environment, they can be used as indicators for monitoring ambient water quality. The objective of this study was to assess possible changes in microbial abundance as a result of concentrate discharge into the near-field area (<. 25. m) surrounding the outfall of the King Abdullah University of Science and Technology (KAUST) SWRO plant. Flow cytometric (FCM) analysis was conducted in order to rapidly determine microbial abundance on a single-cell level in 107 samples, taken by diving, from the discharge area, the intake area and two control sites. FCM analysis combined the measurement of distinct scatter of cells and particles, autofluorescence of cyanobacteria and algae, and fluorescence after staining of nucleic acids with SYBR® Green for a total bacterial count. The results indicate that changes in microbial abundance in the near-field area of the KAUST SWRO outfall are minor and appear to be the result of a dilution effect rather than a direct impact of the concentrate discharge. © 2014 Elsevier B.V.

Effect of gamma irradiation at intermediate doses on the performance of reverse osmosis membranes

International Nuclear Information System (INIS)

Combernoux, Nicolas; Labed, Véronique; Schrive, Luc; Wyart, Yvan; Carretier, Emilie; Moulin, Philippe

2016-01-01

The goal of this study is to explain the degradation of Polyamide (PA) composite reverse osmosis membrane (RO) in function of the irradiation dose. Irradiations were performed with a gamma 60 Co source in wet conditions and under oxygen atmosphere. For different doses of 0.2 and 0.5 MGy with a constant dose rate of 0.5 kGy h −1 , RO membranes performances (NaCl retention, permeability) were studied before and after irradiation. ATR-FTIR, ion chromatography and gas chromatography were used to characterize structural modification. Results showed that the permeability of RO membranes irradiated at 0.2 MGy exhibited a small decrease, related to scissions of the PVA coating. However, retention did not change at this dose. At 0.5 MGy, permeability showed a large increase of a factor around 2 and retention began to decrease from 99% to 95%. Chromatography measurements revealed a strong link between permselectivity properties variation, ion leakage and oxygen consumption. Add to ATR-FTIR observations, these results emphasized that the cleavages of amide and ester bonds were observed at 0.5 MGy, more precisely the loss of hydrogen bonds between polyamide chains. By different analysis, modifications of the polysulfone layer occur until a dose of 0.2 MGy. - Highlights: • Irradiation of RO membranes at intermediate dose (0.2 and 0.5 MGy). • For a dose rate of 0.5 kGy h −1 RO membranes are radiation resistant until 0.2 MGy. • Cleavages of polymer bonds in the active layer at 0.5 MGy. • Decrease in permselectivity properties of the membrane at 0.5 MGy. • High oxygen consumption between 0.2 and 0.5 MGy related to the membranes degradation.

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.

Electro-osmosis of non-Newtonian fluids in porous media using lattice Poisson-Boltzmann method.

Science.gov (United States)

Chen, Simeng; He, Xinting; Bertola, Volfango; Wang, Moran

2014-12-15

Electro-osmosis in porous media has many important applications in various areas such as oil and gas exploitation and biomedical detection. Very often, fluids relevant to these applications are non-Newtonian because of the shear-rate dependent viscosity. The purpose of this study was to investigate the behaviors and physical mechanism of electro-osmosis of non-Newtonian fluids in porous media. Model porous microstructures (granular, fibrous, and network) were created by a random generation-growth method. The nonlinear governing equations of electro-kinetic transport for a power-law fluid were solved by the lattice Poisson-Boltzmann method (LPBM). The model results indicate that: (i) the electro-osmosis of non-Newtonian fluids exhibits distinct nonlinear behaviors compared to that of Newtonian fluids; (ii) when the bulk ion concentration or zeta potential is high enough, shear-thinning fluids exhibit higher electro-osmotic permeability, while shear-thickening fluids lead to the higher electro-osmotic permeability for very low bulk ion concentration or zeta potential; (iii) the effect of the porous medium structure depends significantly on the constitutive parameters: for fluids with large constitutive coefficients strongly dependent on the power-law index, the network structure shows the highest electro-osmotic permeability while the granular structure exhibits the lowest permeability on the entire range of power law indices considered; when the dependence of the constitutive coefficient on the power law index is weaker, different behaviors can be observed especially in case of strong shear thinning. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

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

Impacts of zeolite nanoparticles on substrate properties of thin film nanocomposite membranes for engineered osmosis

Science.gov (United States)

Salehi, Tahereh Mombeini; Peyravi, Majid; Jahanshahi, Mohsen; Lau, Woei-Jye; Rad, Ali Shokuhi

2018-04-01

In this work, microporous substrates modified by zeolite nanoparticles were prepared and used for composite membrane making with the aim of reducing internal concentration polarization (ICP) effect of membranes during engineered osmosis applications. Nanocomposite substrates were fabricated via phase inversion technique by embedding nanostructured zeolite (clinoptilolite) in the range of 0-0.6 wt% into matrix of polyethersulfone (PES) substrate. Of all the substrates prepared, the PES0.4 substrate (with 0.4 wt% zeolite) exhibited unique characteristics, i.e., increased surface porosity, lower structural parameter ( S) (from 0.78 to 0.48 mm), and enhanced water flux. The thin film nanocomposite (TFN) membrane made of this optimized substrate was also reported to exhibit higher water flux compared to the control composite membrane during forward osmosis (FO) and pressure-retarded osmosis (PRO) test, without compromising reverse solute flux. The water flux of such TFN membrane was 43% higher than the control TFC membrane (1.93 L/m2 h bar) with salt rejection recorded at 94.7%. An increment in water flux is ascribed to the reduction in structural parameter, leading to reduced ICP effect.

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.

A study on reverse osmosis permeating treatment for yarn dyeing ...

African Journals Online (AJOL)

This paper presents a fuzzy linear regression model for estimation of reverse osmosis permeating parameters conditions. The proposed model can effectively take on non-crisp, fuzzy and crisp data. This study model used for estimation of reverse osmosis permeating parameters data from Tirupur examines the variables that ...

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 ...

Sensor development for in situ detection of concentration polarization and fouling of reverse osmosis membranes

Science.gov (United States)

Detrich, Kahlil T.; Goulbourne, Nakhiah C.

2009-03-01

The purpose of this research is to evaluate three polymer electroding techniques in developing a novel in situ sensor for an RO system using the electrical response of a thin film composite sensor. Electrical impedance spectroscopy (EIS) was used to measure the sensor response when exposed to sodium chloride solutions with concentrations from 0.1 M to 0.8 M in both single and double bath configurations. An insulated carbon grease sensor was mechanically stable while a composite Direct Assembly Process (DAP) sensor was fragile upon hydration. Scanning electron microscopy results from an impregnation-reduction technique showed gold nanoparticles were deposited most effectively when presoaked in a potassium hydroxide solution and on an uncoated membrane; surface resistances remained too high for sensor implementation. Through thickness carbon grease sensors showed a transient response to changes in concentration, and no meaningful concentration sensitivity was noted for the time scales over which EIS measurements were taken. Surface carbon grease electrodes attached to the polyamide thin film were not sensitive to concentration. The impedance spectra indicated the carbon grease sensor was unable to detect changes in concentration in double bath experiments when implemented with the polyamide surface exposed to salt solutions. DAP sensors lacked a consistent response to changes in concentration too. A reverse double bath experiment with the polysulfone layer exposed to a constant concentration exhibited a transient impedance response similar to through thickness carbon grease sensors in a single bath at constant concentration. These results suggest that the microporous polysulfone layer is responsible for sensor response to concentration.

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

New Dynamic Library of Reverse Osmosis Plants with Fault Simulation

International Nuclear Information System (INIS)

Luis, Palacin; Fernando, Tadeo; Cesar, de Prada; Elfil, Hamza

2009-01-01

This paper presents an update of a dynamic library of reverse osmosis plants (ROSIM). This library has been developed in order to be used for optimization, simulation, controller testing or fault detection strategies and a simple fault tolerant control is tested. ROSIM is based in a set of components representing the different units of a typical reverse osmosis plant (as sand filters, cartridge filters, exchanger energy recoveries, pumps, membranes, storage tanks, control systems, valves, etc.). Different types of fouling (calcium carbonate, iron hydroxide, biofouling) have been added and the mathematical model of the reverse osmosis membranes, proposed in the original library, has been improved.

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.

Effects of N+ implantation on polysaccharide and osmosis stress resistance of liquorice

International Nuclear Information System (INIS)

Wei Shenglin; Wu Lijun; Yu Zengliang

2007-01-01

In order to study the effects of N + implantation on osmosis stress resistance of plant, the experiment was taken with liquorice as plant model and 15% PEG as the osmosis stress agent. The results showed that the stem height growth of liquorice increased by 40.2% compared with controls (p + implantation parameters may be useful to increase osmosis stress resistance cultivation of liquorice and to make it mutated with ions beam implantation. (authors)

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

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.

Surface modification of commercial seawater reverse osmosis membranes by grafting of hydrophilic monomer blended with carboxylated multiwalled carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Vatanpour, Vahid, E-mail: vahidvatanpour@khu.ac.ir; Zoqi, Naser

2017-02-28

Highlights: • A commercial PA RO membrane was modified by grafting of hydrophilic acrylic acid. • COOH-MWCNTs were mixed in grafting layer to increase permeability and antifouling. • However, more increase of CNTs caused in reduction of flux of the membranes. • Effect of acrylic acid amount, contact time and curing time was optimized. - Abstract: In this study, modification of commercial seawater reverse osmosis membranes was carried out with simultaneous use of surface grafting and nanoparticle incorporation. Membrane grafting with a hydrophilic acrylic acid monomer and thermal initiator was used to increase membrane surface hydrophilicity. The used nanomaterial was carboxylated multiwalled carbon nanotubes (MWCNTs), which were dispersed in the grafting solution and deposited on membrane surface to reduce fouling by creating polymer brushes and hydrodynamic resistance. Effectiveness of the grafting process (formation of graft layer on membrane surface) was proved by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses. Increase of membrane surface hydrophilicity was approved with contact angle test. First, the grafting was performed on the membrane surfaces with different monomer concentrations, various contact times and several membrane curing times (three variables for optimization). The modified membranes were tested by a cross-flow setup using saline solution for permeability and rejection tests, and bovine serum albumin (BSA) solution for fouling test. The results showed that the modified membranes with 0.75 M of monomer, 3 min contact time and 80 min curing time in an oven at 50 °C presented the highest flux and lowest rejection decline related to the commercial reverse osmosis membrane. In the next step, the optimum grafting condition was selected and the nanotubes with different weight percentages were dispersed in the acrylic acid monomer solution. The membrane containing 0.25 wt% COOH-MWCNTs showed the

Surface modification of commercial seawater reverse osmosis membranes by grafting of hydrophilic monomer blended with carboxylated multiwalled carbon nanotubes

International Nuclear Information System (INIS)

Vatanpour, Vahid; Zoqi, Naser

2017-01-01

Highlights: • A commercial PA RO membrane was modified by grafting of hydrophilic acrylic acid. • COOH-MWCNTs were mixed in grafting layer to increase permeability and antifouling. • However, more increase of CNTs caused in reduction of flux of the membranes. • Effect of acrylic acid amount, contact time and curing time was optimized. - Abstract: In this study, modification of commercial seawater reverse osmosis membranes was carried out with simultaneous use of surface grafting and nanoparticle incorporation. Membrane grafting with a hydrophilic acrylic acid monomer and thermal initiator was used to increase membrane surface hydrophilicity. The used nanomaterial was carboxylated multiwalled carbon nanotubes (MWCNTs), which were dispersed in the grafting solution and deposited on membrane surface to reduce fouling by creating polymer brushes and hydrodynamic resistance. Effectiveness of the grafting process (formation of graft layer on membrane surface) was proved by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses. Increase of membrane surface hydrophilicity was approved with contact angle test. First, the grafting was performed on the membrane surfaces with different monomer concentrations, various contact times and several membrane curing times (three variables for optimization). The modified membranes were tested by a cross-flow setup using saline solution for permeability and rejection tests, and bovine serum albumin (BSA) solution for fouling test. The results showed that the modified membranes with 0.75 M of monomer, 3 min contact time and 80 min curing time in an oven at 50 °C presented the highest flux and lowest rejection decline related to the commercial reverse osmosis membrane. In the next step, the optimum grafting condition was selected and the nanotubes with different weight percentages were dispersed in the acrylic acid monomer solution. The membrane containing 0.25 wt% COOH-MWCNTs showed the

OPTIMASI DAN PEMODELAN PROSES RECOVER FLAVOR DARI LIMBAH CAIR INDUSTRI PENGOLAHAN RAJUNGAN DENGAN REVERSE OSMOSIS

Directory of Open Access Journals (Sweden)

Uju

2009-04-01

Full Text Available The waste water of blue crab pasteurization has potential in environmental pollution. It contained TSS of 206.5mg.1-1, BOD 7,092.6mg.1-1 and COD of 51,000mg.1-1. on the other hand, it also contains an interesting flavor compound, which composed of 0.23% non protein nitrogen and 17 amino acids where the highest was glutamic acid one. In this study, pre-filtration step using filter size 0.3 µ followed by reverse osmosis has been used to reduce these pollutions load and flavor compound recovery. During pre-filtration steps, TSS was reduced to 74.8% so turbidity decrased reased until 31%. After reverse osmosis process, BOD, and COD decreased more than 99%, and there was no amino acids detected in permeate stream. Factors that affect performance of reverse osmosis were transmembrane pressure, temperature and pH. The higher transmembrane pressure, temperature and pH resulted the higher the flux permeate. The use of higher temperature make flux increasing, eventually increasing transmembrane pressure make the flux increased only at transmembrane pressure less than 716 kPa. The protein rejection was influenced unsignifanctly by transmembrane pressure, temperature and pH. During concentrating flux declined exponentially by time function. At concentration factor 2.75 resulted 79% and 12% of increasing protein and NPN, respectively. The amino acids content can be increased 2−23 times of the origin. Even arginin and sistin, the amino acids that were undetectable initially, but they can bedetected at concentration of 0.0360 and 0.0250 (w/v respectively at the end of the process. Hidrolysis and fermentation process can increase the amino acid content 31−45 times

Application Side Casing on Open Deck RoRo to Improve Ship Stability

Science.gov (United States)

Hasanudin; K. A. P Utama, I.; Chen, Jeng-Horng

2018-03-01

RoRo is a vessel that can transport passengers, cargo, container and cars. Open Car Deck is favourite RoRo Vessel in developing countries due to its small GT, small tax and spacious car deck, but it has poor survival of stability. Many accident involve Open Car Deck RoRo which cause fatalities and victim. In order to ensure the safety of the ship, IMO had applied intact stability criteria IS Code 2008 which adapted from Rahola’s Research, but since 2008 IMO improved criteria become probabilistic damage stability SOLAS 2009. The RoRo type Open Car Deck has wide Breadth (B), small Draft (D) and small freeboard. It has difficulties to satisfy the ship’s stability criteria. Side Casings which has been applied in some RoRo have be known reduce freeboard or improve ship’s safety. In this paper investigated the effect side casings to survival of intact dan damage ship’s stability. Calculation has been conducted for four ships without, existing and full side casings. The investigation results shows that defect stability of Open Deck RoRo can be reduce with fitting side casing.

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

KAUST Repository

Salinas Rodrí guez, S. G.; Kennedy, Maria Dolores; Amy, Gary L.; Schippers, Jan Cornelis

2012-01-01

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

Treatment of radioactive liquid effluents by reverse osmosis membranes: From lab-scale to pilot-scale.

Science.gov (United States)

Combernoux, Nicolas; Schrive, Luc; Labed, Véronique; Wyart, Yvan; Carretier, Emilie; Moulin, Philippe

2017-10-15

The recent use of the reverse osmosis (RO) process at the damaged Fukushima-Daiichi nuclear power plant generated a growing interest in the application of this process for decontamination purposes. This study focused on the development of a robust RO process for decontamination of two kinds of liquid effluents: a contaminated groundwater after a nuclear disaster and a contaminated seawater during a nuclear accident. The SW30 HR membrane was selected among other in this study due to higher retentions (96% for Cs and 98% for Sr) in a true groundwater. Significant fouling and scaling phenomenon, attributed to calcium and strontium precipitation, were evidenced in this work: this underscored the importance of the lab scale experiment in the process. Validation of the separation performances on trace radionuclides concentration was performed with similar retention around 96% between surrogates Cs (inactive) and 137 Cs (radioactive). The scale up to a 2.6 m 2 spiral wound membrane led to equivalent retentions (around 96% for Cs and 99% for Sr) but lower flux values: this underlined that the hydrodynamic parameters (flowrate/cross-flow velocity) should be optimized. This methodology was also applied on the reconstituted seawater effluent: retentions were slightly lower than for the groundwater and the same hydrodynamic effects were observed on the pilot scale. Then, ageing of the membrane through irradiation experiments were performed. Results showed that the membrane active layer composition influenced the membrane resistance towards γ irradiation: the SW30 HR membrane performances (retention and permeability) were better than the Osmonics SE at 1 MGy. Finally, to supplement the scale up approach, the irradiation of a spiral wound membrane revealed a limited effect on the permeability and retention. This indicated that irradiation conditions need to be controlled for a further development of the process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Boron removal in radioactive liquid waste by forward osmosis membrane

Energy Technology Data Exchange (ETDEWEB)

Doo Seong Hwang; Hei Min Choi; Kune Woo Lee; Jei Kwon Moon [KAERI, Daejeon (Korea, Republic of)

2013-07-01

This study investigated the treatment of boric acid contained in liquid radioactive waste using a forward osmosis membrane. The boron permeation through the membrane depends on the type of membrane, membrane orientation, pH of the feed solution, salt and boron concentration in the feed solution, and osmotic pressure of the draw solution. The boron flux begins to decline from pH 7 and increases with an increase of the osmotic driving force. The boron flux decreases slightly with the salt concentration, but is not heavily influenced by a low salt concentration. The boron flux increases linearly with the concentration of boron. No element except for boron was permeated through the FO membrane in the multi-component system. The maximum boron flux is obtained in an active layer facing a draw solution orientation of the CTA-ES membrane under conditions of less than pH 7 and high osmotic pressure. (authors)

In-depth analyses of organic matters in a full-scale seawater desalination plant and an autopsy of reverse osmosis membrane

KAUST Repository

Jeong, Sanghyun; Naidu, Gayathri; Vollprecht, Robert; Leiknes, TorOve; Vigneswaran, Saravanamuthu

2016-01-01

In order to facilitate the global performance of seawater reverse osmosis (SWRO) systems, it is important to improve the feed water quality before it enters the RO. Currently, many desalination plants experience production losses due to incidents of organic and biofouling. Consequently, monitoring or characterizing the pretreatment step using more advanced organic and biological parameters are required for better operation to lessen fouling issues. In this study, the performance of pretreatment processes (including coagulation, dual media filtration (DMF), polishing with cartridge filter (CF) coupled with anti-scalant) used at Perth Seawater Desalination Plant (PSDP) located in Western Australia were characterized in terms of organic and biological fouling parameters. These analyses were carried out using liquid chromatography with organic carbon detector (LC-OCD), three dimensional-fluorescence excitation emission matrix (3D-FEEM) and assimilable organic carbon (AOC). Furthermore, the used (exhausted) RO membrane and CF were autopsied so that the fates and behaviors of organic foulants in these treatment systems could be better understood.

In-depth analyses of organic matters in a full-scale seawater desalination plant and an autopsy of reverse osmosis membrane

KAUST Repository

Jeong, Sanghyun

2016-02-17

In order to facilitate the global performance of seawater reverse osmosis (SWRO) systems, it is important to improve the feed water quality before it enters the RO. Currently, many desalination plants experience production losses due to incidents of organic and biofouling. Consequently, monitoring or characterizing the pretreatment step using more advanced organic and biological parameters are required for better operation to lessen fouling issues. In this study, the performance of pretreatment processes (including coagulation, dual media filtration (DMF), polishing with cartridge filter (CF) coupled with anti-scalant) used at Perth Seawater Desalination Plant (PSDP) located in Western Australia were characterized in terms of organic and biological fouling parameters. These analyses were carried out using liquid chromatography with organic carbon detector (LC-OCD), three dimensional-fluorescence excitation emission matrix (3D-FEEM) and assimilable organic carbon (AOC). Furthermore, the used (exhausted) RO membrane and CF were autopsied so that the fates and behaviors of organic foulants in these treatment systems could be better understood.

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)

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)

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...

Reverse-osmosis membranes by plasma polymerization

Science.gov (United States)

Hollahan, J. R.; Wydeven, T.

1972-01-01

Thin allyl amine polymer films were developed using plasma polymerization. Resulting dry composite membranes effectively reject sodium chloride during reverse osmosis. Films are 98% sodium chloride rejective, and 46% urea rejective.

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.

Effects of Fining Agents, Reverse Osmosis and Wine Age on Brown Marmorated Stink Bug (Halyomorpha halys Taint in Wine

Directory of Open Access Journals (Sweden)

Pallavi Mohekar

2018-03-01

Full Text Available Trans-2-decenal and tridecane are compounds found in wine made from brown marmorated stink bug (BMSB-contaminated grapes. The effectiveness of post-fermentation processes on reducing their concentration in finished wine and their longevity during wine aging was evaluated. Red wines containing trans-2-decenal were treated with fining agents and put through reverse osmosis filtration. The efficacy of these treatments was determined using chemical analysis (MDGC-MS and sensory descriptive analysis. Tridecane and trans-2-decenal concentrations in red and white wine were determined at bottle aging durations of 0, 6, 12 and 24 months using MDGC-MS. Reverse osmosis was found to be partially successful in removing trans-2-decenal concentration from finished wine. While tridecane and trans-2-decenal concentrations decreased during bottle aging, post-fermentative fining treatments were not effective at removing these compounds. Although French oak did not alter the concentration of tridecane and trans-2-decenal in red wine, it did mask the expression of BMSB-related sensory characters. Because of the ineffectiveness of removing BMSB taint post-fermentation, BMSB densities in the grape clusters should be minimized so that the taint does not occur in the wine.

Construction of a dead-end type micro- to R.O. membrane test cell and performance test with the laboratory- made and commercial membranes

Directory of Open Access Journals (Sweden)

Darunee Bhongsuwan

2002-11-01

Full Text Available A dead-end type membrane stirred cell for an RO filtration test has been designed and constructed. Magnetic stirring system is applied to overcome a pressure-induced concentration polarization occurred over a membrane surface in the test cell. A high pressure N2 tank is used as a pressure source.Feed container is designed for 2.5 l feed solution and a stirred cell volume is 0.5 l . The test cell holds a magnetic stirrer freely moved over the membrane surface. All units are made of stainless steel. A porous SS316L disc is used as a membrane support. The dead-end stirred cell is tested to work properly in an operating pressure ranged 0 - 400 psi. It means that the dead-end cell can be used to test a membrane of different filtration modes, from micro- to Reverse Osmosis filtration. Tests performed at 400 psi for 3 hours are safe but tests at a 500 psi increase leakage possibility. The cell is used to test the performance of both commercial and laboratory-made membranes. It shows that the salt rejection efficiency of the nano- and RO membranes, NTR759HR and LES90, determined by using the new test cell, is closely similar to those reported from the manufacture. Result of the tests for our own laboratory-made membrane shows a similar performance to the nanofiltration membrane LES90.

Chaotic micromixer utilizing electro-osmosis and induced charge electro-osmosis in eccentric annulus

International Nuclear Information System (INIS)

Feng, Huicheng; Wong, Teck Neng; Marcos; Che, Zhizhao

2016-01-01

Efficient mixing is of significant importance in numerous chemical and biomedical applications but difficult to realize rapidly in microgeometries due to the lack of turbulence. We propose to enhance mixing by introducing Lagrangian chaos through electro-osmosis (EO) or induced charge electro-osmosis (ICEO) in an eccentric annulus. The analysis reveals that the created Lagrangian chaos can achieve a homogeneous mixing much more rapidly than either the pure EO or the pure ICEO. Our systematic investigations on the key parameters, ranging from the eccentricity, the alternating time period, the number of flow patterns in one time period, to the specific flow patterns utilized for the Lagrangian chaos creation, present that the Lagrangian chaos is considerably robust. The system can obtain a good mixing effect with wide ranges of eccentricity, alternating time period, and specific flow patterns utilized for the Lagrangian chaos creation as long as the number of flow patterns in one time period is two. As the electric field increases, the time consumption for homogenous mixing is reduced more remarkably for the Lagrangian chaos of the ICEO than that of the EO.

Chaotic micromixer utilizing electro-osmosis and induced charge electro-osmosis in eccentric annulus

Energy Technology Data Exchange (ETDEWEB)

Feng, Huicheng; Wong, Teck Neng, E-mail: mtnwong@ntu.edu.sg; Marcos [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Che, Zhizhao [State Key Laboratory of Engines, Tianjin University, Tianjin 300072 (China)

2016-06-15

Efficient mixing is of significant importance in numerous chemical and biomedical applications but difficult to realize rapidly in microgeometries due to the lack of turbulence. We propose to enhance mixing by introducing Lagrangian chaos through electro-osmosis (EO) or induced charge electro-osmosis (ICEO) in an eccentric annulus. The analysis reveals that the created Lagrangian chaos can achieve a homogeneous mixing much more rapidly than either the pure EO or the pure ICEO. Our systematic investigations on the key parameters, ranging from the eccentricity, the alternating time period, the number of flow patterns in one time period, to the specific flow patterns utilized for the Lagrangian chaos creation, present that the Lagrangian chaos is considerably robust. The system can obtain a good mixing effect with wide ranges of eccentricity, alternating time period, and specific flow patterns utilized for the Lagrangian chaos creation as long as the number of flow patterns in one time period is two. As the electric field increases, the time consumption for homogenous mixing is reduced more remarkably for the Lagrangian chaos of the ICEO than that of the EO.

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

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

OSMOSIS: A CAUSE OF APPARENT DEVIATIONS FROM DARCY'S LAW.

Science.gov (United States)

Olsen, Harold W.

1985-01-01

This review of the existing evidence shows that osmosis causes intercepts in flow rate versus hydraulic gradient relationships that are consistent with the observed deviations from Darcy's law at very low gradients. Moreover, it is suggested that a natural cause of osmosis in laboratory samples could be chemical reactions such as those involved in aging effects. This hypothesis is analogous to the previously proposed occurrence of electroosmosis in nature generated by geochemical weathering reactions. Refs.

Simultaneous removal of organic matter and salt ions from coal gasification wastewater RO concentrate and microorganisms succession in a MBR.

Science.gov (United States)

Jia, Shengyong; Han, Yuxing; Zhuang, Haifeng; Han, Hongjun; Li, Kun

2017-10-01

A lab-scale membrane bioreactor (MBR) with intermittent aeration was operated to treat the reverse osmosis concentrate derived from coal gasification wastewater. Results showed intermittent aeration represented slight effect on organic matter reduction but significant effect on nitrite and nitrate reduction, with 6h aeration and 6h non-aeration, removal efficiencies of organic matter, chloride, sulfate, nitrite and nitrate reached 48.35%, 40.91%, 34.28%, -36.05% and 64.34%, respectively. High-throughput sequencing showed a microorganisms succession from inoculated activated sludge (S1) to activated sludge in MBR (S2) with high salinity. Richness and diversity of microorganisms in S2 was lower than S1 and the community structure of S1 exhibited more even than S2. The most relative abundance of genus in S1 and S2 were unclassified_Desulfarculaceae (9.39%) and Roseibaca (62.1%), respectively. High salinity and intermittent aeration represented different influence on the denitrifying genus, and non-aeration phase provided feasible dissolved oxygen condition for denitrifying genera realizing denitrification. Copyright © 2017 Elsevier Ltd. All rights reserved.

Infrasonic backpulsed membrane cleaning of micro- and ...

African Journals Online (AJOL)

2011-08-29

Aug 29, 2011 ... become prominent in water treatment for domestic and indus- trial water ... fouling and cleaning in a reverse osmosis (RO) system, and showed that the .... used to make yeast suspensions with concentrations of 1 g/ℓ. Alumina ...

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.

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.

Inhibitory Effects of Cytosolic Ca2+ Concentration by Ginsenoside Ro Are Dependent on Phosphorylation of IP3RI and Dephosphorylation of ERK in Human Platelets

Directory of Open Access Journals (Sweden)

Hyuk-Woo Kwon

2015-01-01

Full Text Available Intracellular Ca2+ ([Ca2+]i is platelet aggregation-inducing molecule and is involved in activation of aggregation associated molecules. This study was carried out to understand the Ca2+-antagonistic effect of ginsenoside Ro (G-Ro, an oleanane-type saponin in Panax ginseng. G-Ro, without affecting leakage of lactate dehydrogenase, dose-dependently inhibited thrombin-induced platelet aggregation, and the half maximal inhibitory concentration was approximately 155 μM. G-Ro inhibited strongly thrombin-elevated [Ca2+]i, which was strongly increased by A-kinase inhibitor Rp-8-Br-cAMPS compared to G-kinase inhibitor Rp-8-Br-cGMPS. G-Ro increased the level of cAMP and subsequently elevated the phosphorylation of inositol 1, 4, 5-triphosphate receptor I (IP3RI (Ser1756 to inhibit [Ca2+]i mobilization in thrombin-induced platelet aggregation. Phosphorylation of IP3RI (Ser1756 by G-Ro was decreased by PKA inhibitor Rp-8-Br-cAMPS. In addition, G-Ro inhibited thrombin-induced phosphorylation of ERK 2 (42 kDa, indicating inhibition of Ca2+ influx across plasma membrane. We demonstrate that G-Ro upregulates cAMP-dependent IP3RI (Ser1756 phosphorylation and downregulates phosphorylation of ERK 2 (42 kDa to decrease thrombin-elevated [Ca2+]i, which contributes to inhibition of ATP and serotonin release, and p-selectin expression. These results indicate that G-Ro in Panax ginseng is a beneficial novel Ca2+-antagonistic compound and may prevent platelet aggregation-mediated thrombotic disease.

Fabrication and performance of PET mesh enhanced cellulose acetate membranes for forward osmosis.

Science.gov (United States)

Li, Guoliang; Wang, Jun; Hou, Deyin; Bai, Yu; Liu, Huijuan

2016-07-01

Polyethylene terephthalate mesh (PET) enhanced cellulose acetate membranes were fabricated via a phase inversion process. The membrane fabrication parameters that may affect the membrane performance were systematically evaluated including the concentration and temperature of the casting polymer solution and the temperature and time of the evaporation, coagulation and annealing processes. The water permeability and reverse salt flux were measured in forward osmosis (FO) mode for determination of the optimal membrane fabrication conditions. The optimal FO membrane shows a typical asymmetric sandwich structure with a mean thickness of about 148.2μm. The performance of the optimal FO membrane was tested using 0.2mol/L NaCl as the feed solution and 1.5mol/L glucose as the draw solution. The membrane displayed a water flux of 3.47L/(m(2)·hr) and salt rejection of 95.48% in FO mode. While in pressure retarded osmosis (PRO) mode, the water flux was 4.74L/(m(2)·hr) and salt rejection 96.03%. The high ratio of water flux in FO mode to that in PRO mode indicates that the fabricated membrane has a lower degree of internal concentration polarization than comparable membranes. Copyright © 2016. Published by Elsevier B.V.

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

Energy recovery by pressure retarded osmosis (PRO) in SWRO–PRO integrated processes

KAUST Repository

Wan, Chun Feng; Chung, Neal Tai-Shung

2015-01-01

Pressure retarded osmosis (PRO) is a promising technology to reduce the specific energy consumption of a seawater reverse osmosis (SWRO) plant. In this study, it is projected that 25.6-40.7millionkWh/day of energy can be recovered globally

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…

Embracing Learners' Ideas about Diffusion and Osmosis: A Coupled-Inquiry Approach

Science.gov (United States)

Sweeney, Ryan M.; Martin-Hansen, Lisa; Verma, Geeta; Dunkhase, John

2009-01-01

Learning about osmosis and diffusion is often a challenging task for middle school students. Here the authors present a lesson that was converted from a "cookbook" lab (McLaughlin and Thompson 2007) into a more inquiry-oriented lab that uses inquiry teaching strategies and hands-on investigations to teach middle-grade students about osmosis and…

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

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

Experimental study of the electrode material for electro-osmosis in mudflat sludge

Science.gov (United States)

Liu, Yi-min; Xu, Hao-feng

2017-11-01

In order to study the performance of electro-osmosis, several tests including indoor electro-osmosis experiments using copper, aluminum as the anode and cathode electrode materials, and Mercury Intrusion Porosimiter (MIP) were conducted. The results indicate that the drainage ratio using aluminum is faster than that of copper while the energy consumption per unit is lower, the effectiveness is better than that of copper. After electro-osmosis, the percentage of pore with large diameter shows a remarkable decrease comparing with the remolded soil which result in the increase of pore with small diameter. The reasons were discussed in this paper.

The treatment of radioactive aqueous wastes by reverse osmosis

International Nuclear Information System (INIS)

Hodgson, T.D.

Experiments were carried out to determine the rejection factors for the more important radionuclides found in aqueous wastes, to study activity deposition within reverse osmosis modules, and to obtain experience in active operation of a reverse osmosis facility. It was found that reverse osmosis is likely to be useful in aqueous radioactive waste treatment when a wide range of contaminants rather than a specific radioactive species must be removed. There appeared to be no barrier to active operation, although greater confidence in the reliability of pumps and membranes is needed. The rejection of trace quantities of radioisotopes such as Cs + or Sr ++ could be predicted from the behaviour of similar inactive ions. Activity present as polyvalent ions or colloidal aggregates is highly rejected by the membrane. Activity may be deposited onto the membrane with insoluble or scaling compounds, and is greatest on areas of the membrane shielded from the sweeping action of the liquor flow

Early non-destructive biofouling detection in spiral wound RO Membranes using a mobile earth's field NMR

KAUST Repository

Fridjonsson, E.O.; Vogt, S.J.; Vrouwenvelder, Johannes S.; Johns, M.L.

2015-01-01

We demonstrate the use of Earth's field (EF) Nuclear Magnetic Resonance (NMR) to provide early non-destructive detection of active biofouling of a commercial spiral wound reverse osmosis (RO) membrane module. The RO membrane module was actively biofouled to different extents, by the addition of biodegradable nutrients to the feed stream, as revealed by a subtle feed-channel pressure drop increase. Easily accessible EF NMR parameters (signal relaxation parameters T1, T2 and the total NMR signal modified to be sensitive to stagnant fluid only) were measured and analysed in terms of their ability to detect the onset of biofouling. The EF NMR showed that fouling near the membrane module entrance significantly distorted the flow field through the whole membrane module. The total NMR signal is shown to be suitable for non-destructive early biofouling detection of spiral wound membrane modules, it was readily deployed at high (operational) flow rates, was particularly sensitive to flow field changes due to biofouling and could be deployed at any position along the membrane module axis. In addition to providing early fouling detection, the mobile EF NMR apparatus could also be used to (i) evaluate the production process of spiral wound membrane modules, and (ii) provide an in-situ determination of module cleaning process efficiency.

Early non-destructive biofouling detection in spiral wound RO Membranes using a mobile earth's field NMR

KAUST Repository

Fridjonsson, E.O.

2015-04-20

We demonstrate the use of Earth\\'s field (EF) Nuclear Magnetic Resonance (NMR) to provide early non-destructive detection of active biofouling of a commercial spiral wound reverse osmosis (RO) membrane module. The RO membrane module was actively biofouled to different extents, by the addition of biodegradable nutrients to the feed stream, as revealed by a subtle feed-channel pressure drop increase. Easily accessible EF NMR parameters (signal relaxation parameters T1, T2 and the total NMR signal modified to be sensitive to stagnant fluid only) were measured and analysed in terms of their ability to detect the onset of biofouling. The EF NMR showed that fouling near the membrane module entrance significantly distorted the flow field through the whole membrane module. The total NMR signal is shown to be suitable for non-destructive early biofouling detection of spiral wound membrane modules, it was readily deployed at high (operational) flow rates, was particularly sensitive to flow field changes due to biofouling and could be deployed at any position along the membrane module axis. In addition to providing early fouling detection, the mobile EF NMR apparatus could also be used to (i) evaluate the production process of spiral wound membrane modules, and (ii) provide an in-situ determination of module cleaning process efficiency.

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...

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.

A flux-enhancing forward osmosis-nanofiltration integrated treatment system for the tannery wastewater reclamation.

Science.gov (United States)

Pal, Parimal; Chakrabortty, Sankha; Nayak, Jayato; Senapati, Suman

2017-06-01

Effective treatment of tannery wastewater prior to discharge to the environment as per environmental regulations remains a big challenge despite efforts to bring down the concentrations of the pollutants which are often quite high as measured in terms of chemical oxygen demand (7800 mg/L), total dissolved solids (5400 mg/L), chloride (4260 mg/L), sulphides (250 mg/L) and chromium. A pilot-scale forward osmosis and nanofiltration integrated closed loop system was developed for continuous reclamation of clean water from tannery wastewater at a rate of 52-55 L/m 2 /h at 1.6 bar pressure. The low-cost draw solution was 0.8 M NaCl solution. Continuous recovery for recycling the draw solute was done by nanofiltration of diluted draw solution at an operating pressure of 12 bar and volumetric cross-flow rate of 700 L/h. Fouling study revealed that the specific flat-sheet design of cross-flow forward osmosis module with counter current flow of feed and draw solution prevents the build-up of concentration polarization, thus enabling long-term filtration in continuous mode of operation without significant membrane fouling. This study culminates in the development of a compact, efficient and low-cost industrial wastewater treatment and reclamation technology.

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.

Research on rejection performance of reverse osmosis to nickel in simulated radioactive wastewater

International Nuclear Information System (INIS)

Kong Jinsong; Wang Xiaowei

2013-01-01

In order to reveal the rejection performance of the reverse osmosis applied in the radioactive wastewater treatment, treatment experiments were carried out on a pilot reverse osmosis equipment using wastewater containing nickel nuclide. Results showed that the rejection ratio of reverse osmosis to nickel was almost not affected by the operation pressure and the ratio of reclaiming, and had no direct relation with the salt rejection ratio. The ratio of nickel rejection reached 95% in the experiment condition and could meet the requirement on the disposal of radioactive wastewater produced by nuclear powered installations. (authors)

Research on rejection performance of reverse osmosis to cobalt in simulated radioactive wastewater

International Nuclear Information System (INIS)

Kong Jinsong; Tian Yanjie

2012-01-01

In order to reveal the rejection performance of the reverse osmosis applied in the radioactive wastewater treatment, treatment experiments were carried out on a pilot reverse osmosis equipment using wastewater containing cobalt nuclide. Results showed that the rejection ratio of reverse osmosis to cobalt was almost not affected by the operation pressure and the ratio of reclaiming, and had no direct relation with the salt rejection ratio. The ratio of cobalt rejection reached 90% in the experiment condition and could meet the requirement on the disposal of radioactive wastewater produced by nuclear powered installations. (authors)

Influences of mechanical pre-treatment on the non-biological treatment of municipal wastewater by forward osmosis

DEFF Research Database (Denmark)

Hey, Tobias; Zarebska, Agata; Bajraktari, Niada

2016-01-01

municipal wastewater treatment without the biological treatment step, including the effects of different pre-treatment configurations, e.g., direct membrane filtration before forward osmosis. Forward osmosis was tested using raw wastewater and wastewater subjected to different types of mechanical pre-treatment......, e.g., microsieving and microfiltration permeation, as a potential technology for municipal wastewater treatment. Forward osmosis was performed using thin-film-composite, Aquaporin Inside(TM) and HTI membranes with NaCl as the draw solution. Both types of forward osmosis membranes were tested......-sized wastewater treatment plants....

Expansion of thermodynamic model of solute permeation through reverse osmosis membrane

International Nuclear Information System (INIS)

Nishimaki, Kenzo; Koyama, Akio

1994-01-01

Many studies have been performed on permeation mechanism of solute and solvent in membrane separation process like reverse osmosis or ultrafiltration, and several models of solute/solvent permeation through membrane are proposed. Among these models, Kedem and Katchalsky, based on the theory of thermodynamics of irreversible processes, formulated the one-solute permeation process in their mathematical model, which treats membrane as a black box, not giving consideration to membrane structure and to interaction between membrane material and permeates, viz. solute and solvent. According to this theory, the driving force of solute/solvent permeation through membrane is the difference of their chemical potential between both sides of membrane, and the linear phenomenological equation is applied to describing the relation between driving force and flux of solute/solvent. This equation can be applied to the irreversible process only when the process is almost in equilibrium. This condition is supposed to be satisfied in the solute/solvent permeation process through compact membrane with fine pores like reverse osmosis membrane. When reverse osmosis is applied to treatment process for liquid waste, which usually contains a lot of solutes as contaminants, we can not predict the behavior of contaminants by the above one-solute process model. In the case of multi-solutes permeation process for liquid waste, the number of parameter in thermodynamic model increases rapidly with the number of solute, because of coupling phenomenon among solutes. In this study, we expanded the above thermodynamic model to multi-solute process applying operational calculus to the differential equations which describe the irreversible process of the system, and expressed concisely solute concentration vector as a matrix product. In this way, we predict the behavior of solutes in multi-solutes process, using values of parameters obtained in two-solutes process. (author)

Probabilistic Analysis of Collision Damages with Application to ro-Ro Passenger Vessels

DEFF Research Database (Denmark)

Pedersen, Preben Terndrup; Hansen, Peter Friis; Nielsen, Lars Peter

1997-01-01

To quantify the risks involved in Ro-ro passenger vessel traffic, rational criteria for prediction and evaluation of collision accidents have to be developed. This implies that probabilities as well as the inherent consequences have to be analyzed and assessed.The present report outlines a method...... for evaluation of the probability of a Ro-Ro passenger vessel on a given route being struck by another ship. Given a collision has taken place the spatial distribution of the collision damages is calculated. Results are presented in terms of probability distributions, for indentation depth, length and height...... of the holes and for the vertical location. The main benefit of the formulated procedure is that it allows comparisons of various navigation routes by assessing the relative frequencies of collisions. The derived procedure is applied to two typical Ro-Ro passenger vessel routes....

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...

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.

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.

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.

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

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.

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.

Role of membrane fouling substances on the rejection of N-nitrosamines by reverse osmosis.

Science.gov (United States)

Fujioka, Takahiro; Kodamatani, Hitoshi; Aizawa, Hidenobu; Gray, Stephen; Ishida, Kenneth P; Nghiem, Long D

2017-07-01

The impact of fouling substances on the rejection of four N-nitrosamines by a reverse osmosis (RO) membrane was evaluated by characterizing individual organic fractions in a secondary wastewater effluent and deploying a novel high-performance liquid chromatography-photochemical reaction-chemiluminescence (HPLC-PR-CL) analytical technique. The HPLC-PR-CL analytical technique allowed for a systematic examination of the correlation between the fouling level and the permeation of N-nitrosamines in the secondary wastewater effluent and synthetic wastewaters through an RO membrane. Membrane fouling caused by the secondary wastewater effluent led to a notable decrease in the permeation of N-nitrosodimethylamine (NDMA) while a smaller but nevertheless discernible decrease in the permeation of N-nitrosomethylethylamine (NMEA), N-nitrosopyrrolidine (NPYR) and N-nitrosomorpholine (NMOR) was also observed. Fluorescence spectrometry analysis revealed that major foulants in the secondary wastewater effluent were humic and fulvic acid-like substances. Analysis using the size exclusion chromatography technique also identified polysaccharides and proteins as additional fouling substances. Thus, further examination was conducted using solutions containing model foulants (i.e., sodium alginate, bovine serum albumin, humic acid and two fulvic acids). Similar to the secondary wastewater effluent, membrane fouling with fulvic acid solutions resulted in a decrease in N-nitrosamine permeation. In contrast, membrane fouling with the other model foulants resulted in a negligible impact on N-nitrosamine permeation. Overall, these results suggest that the impact of fouling on the permeation of N-nitrosamines by RO is governed by specific small organic fractions (e.g. fulvic acid-like organics) in the secondary wastewater effluent. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Application of reverse osmosis to the treatment of liquid effluents produced by nuclear power plants

International Nuclear Information System (INIS)

Huet, Y.; Poulat, B.; Menjeaud, C.

1989-01-01

Radioactive liquid effluents generated during the operation of PWR nuclear power units are currently treated by two independent systems. The effluents from the reactor coolant system are recycled, unlike the others, which, after treatment, are released into the river or ocean that provides cooling water for the unit. The objective of the treatment of nonrecycled effluents is to separate from them as much of the radioactive particles that they contain as possible, so as to release into the environment a maximum volume of nonradioactive waste, and to be left with only a minimum volume of concentrated waste, containing most of the initial radioactivity, which must be loaded into casks for storage. Membrane-based filtration techniques, because they have excellent separation performances, can logically be used for this decontamination of the liquid effluents. Having developed its own reverse osmosis membrane, a possible application in a nuclear power plant, i.e., integration of a reverse osmosis unit into a radioactive liquid effluent treatment system is presented. (author)

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.

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.

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