A Review of Ultrafiltration and Forward Osmosis:application and modification

NASA Astrophysics Data System (ADS)

Chao, Gong; Shuili, Yu; Yufei, Shangguan; Zhengyang, Gu; Wangzhen, Yang; Liumo, Ren

2018-03-01

As a new treatment, membrane filtration is playing a more prominent role in treating many kinds of wastewater. Among all the membrane technologies, ultrafiltration(UF) and forward osmosis(FO) technology has been widely utilized and developed in oil field and refinery produced water. However, the reports about the differences between the two kinds of membrane technology used in oily wastewater are not yet available. In this review, at first we introduce the advantages, shortcomings and applications of UF and FO membranes. Among these, we mainly illustrate the membrane fouling, which now is a big problem because it increases costs and decreases membrane life to limit the industrialization of the membrane, and the different modification methods of membranes are discussed to figure out how these ways can ease the membrane fouling. Next we make a comparison of the two membranes. Finally we illustrate the future research topics.

Summary of the ultrafiltration, reverse osmosis, and adsorbents project

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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

2011-06-01

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

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

EPA Science Inventory

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

300 GPM Solids Removal System A True Replacement for Back Flushable Powdered Filter Systems - 13607

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ping, Mark R.; Lewis, Mark

2013-07-01

The EnergySolutions Solids Removal System (SRS) utilizes stainless steel cross-flow ultra-filtration (XUF) technology which allows it to reliably remove suspended solids greater than one (1) micron from liquid radwaste streams. The SRS is designed as a pre-treatment step for solids separation prior to processing through other technologies such as Ion Exchange Resin (IER) and/or Reverse Osmosis (RO), etc. Utilizing this pre-treatment approach ensures successful production of reactor grade water while 1) decreasing the amount of radioactive water being discharged to the environment; and 2) decreasing the amount of radioactive waste that must ultimately be disposed of due to the eliminationmore » of spent powdered filter media. (authors)« less

Performance of ceramic ultrafiltration and reverse osmosis membranes in treating car wash wastewater for reuse.

PubMed

Moazzem, Shamima; Wills, Jamie; Fan, Linhua; Roddick, Felicity; Jegatheesan, Veeriah

2018-03-01

Reusing treated effluents in industries is a great option to conserve freshwater resources. For example, car wash centres all over Australia are estimated to use 17.5 billion litres of water and discharge it as wastewater and spend $75 million a year for both purchasing fresh water and for treating and/or discharging the wastewater. Therefore, it is important to develop simple but reliable systems that can help to treat and reuse car wash wastewater. Significant savings could also be associated with the implementation of such systems. This study evaluates the performance of granular and membrane filtration systems with coagulation/flocculation and sedimentation in treating car wash wastewater for the purpose of reuse. Overall, 99.9% of turbidity, 100% of suspended solids and 96% of COD were removed from the car wash wastewater after treating by coagulation, flocculation, sedimentation, sand filtration, ceramic ultrafiltration and reverse osmosis and the treated water meets the standards required for class A recycled water in Australia and standards imposed in Belgium and China. The treated water can be reused. However, optimisation is required to reduce the sludge produced by this system.

Reverse osmosis desalination: water sources, technology, and today's challenges.

PubMed

Greenlee, Lauren F; Lawler, Desmond F; Freeman, Benny D; Marrot, Benoit; Moulin, Philippe

2009-05-01

Reverse osmosis membrane technology has developed over the past 40 years to a 44% share in world desalting production capacity, and an 80% share in the total number of desalination plants installed worldwide. The use of membrane desalination has increased as materials have improved and costs have decreased. Today, reverse osmosis membranes are the leading technology for new desalination installations, and they are applied to a variety of salt water resources using tailored pretreatment and membrane system design. Two distinct branches of reverse osmosis desalination have emerged: seawater reverse osmosis and brackish water reverse osmosis. Differences between the two water sources, including foulants, salinity, waste brine (concentrate) disposal options, and plant location, have created significant differences in process development, implementation, and key technical problems. Pretreatment options are similar for both types of reverse osmosis and depend on the specific components of the water source. Both brackish water and seawater reverse osmosis (RO) will continue to be used worldwide; new technology in energy recovery and renewable energy, as well as innovative plant design, will allow greater use of desalination for inland and rural communities, while providing more affordable water for large coastal cities. A wide variety of research and general information on RO desalination is available; however, a direct comparison of seawater and brackish water RO systems is necessary to highlight similarities and differences in process development. This article brings to light key parameters of an RO process and process modifications due to feed water characteristics.

Polishing Step Purification of High-Strength Wastewaters by Nanofiltration and Reverse Osmosis

PubMed Central

Zhou, Jinxiang; Baker, Brian O.; Grimsley, Charles T.; Husson, Scott M.

2016-01-01

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. PMID:26978407

Development of a two-stage membrane-based wash-water reclamation subsystem

NASA Technical Reports Server (NTRS)

Mccray, S. B.

1988-01-01

A two-stage membrane-based subsystem was designed and constructed to enable the recycle of wash waters generated in space. The first stage is a fouling-resistant tube-side-feed hollow-fiber ultrafiltration module, and the second stage is a spiral-wound reverse-osmosis module. Throughout long-term tests, the subsystem consistently produced high-quality permeate, processing actual wash water to 95 percent recovery.

Nanotechnology-based water treatment strategies.

PubMed

Kumar, Sandeep; Ahlawat, Wandit; Bhanjana, Gaurav; Heydarifard, Solmaz; Nazhad, Mousa M; Dilbaghi, Neeraj

2014-02-01

The most important component for living beings on the earth is access to clean and safe drinking water. Globally, water scarcity is pervasive even in water-rich areas as immense pressure has been created by the burgeoning human population, industrialization, civilization, environmental changes and agricultural activities. The problem of access to safe water is inevitable and requires tremendous research to devise new, cheaper technologies for purification of water, while taking into account energy requirements and environmental impact. This review highlights nanotechnology-based water treatment technologies being developed and used to improve desalination of sea and brackish water, safe reuse of wastewater, disinfection and decontamination of water, i.e., biosorption and nanoadsorption for contaminant removal, nanophotocatalysis for chemical degradation of contaminants, nanosensors for contaminant detection, different membrane technologies including reverse osmosis, nanofiltration, ultrafiltration, electro-dialysis etc. This review also deals with the fate and transport of engineered nanomaterials in water and wastewater treatment systems along with the risks associated with nanomaterials.

Ultrafiltration by a compacted clay membrane-II. Sodium ion exclusion at various ionic strengths

USGS Publications Warehouse

Hanshaw, B.B.; Coplen, T.B.

1973-01-01

Several recent laboratory studies and field investigations have indicated that shales and compacted clay minerals behave as semipermeable membranes. One of the properties of semipermeable membranes is to retard or prevent the passage of charged ionic species through the membrane pores while allowing relatively free movement of uncharged species. This phenomenon is termed salt filtering, reverse osmosis, or ultrafiltration. This paper shows how one can proceed from the ion exchange capacity of clay minerals and, by means of Donnan membrane equilibrium concept and the Teorell-Meyer-Siever theory, develop a theory to explain why and to what extent ultrafiltration occurs when solutions of known concentration are forced to flow through a clay membrane. Reasonable agreement between theory and laboratory results were found. The concentration of the ultrafiltrate was always greater than predicted because of uncertainty in values of some parameters in the equations. Ultrafiltration phenomena may be responsible for the formation of some subsurface brines and mineral deposits. The effect should also be taken into consideration in any proposal for subsurface waste emplacement in an environment containing large quantities of clay minerals. ?? 1973.

Membrane Treatment of Aqueous Film Forming Foam (AFFF) Wastes for Recovery of Its Active Ingredients

DTIC Science & Technology

1980-10-01

T ME1MBRANE TREATMENT OF AQUEOUS FILM FORMING FOAM~ (AFFF) WASTES FOR RECOVERY OFI Fts ACTIVE INGREDIENTS FINAL REPORT October 1980 by Edward S. K...OF THIS PAGEOPMn Date AVntr* d)__ ---- Ultrafiltration (UF) and Reverse Osmosis (RO) treatment of Aqueous Film Forming Foam (AFFF) solutions was...of Aqueous Film Forming Foam (AFFF) solutions was investigated to determine the feasibility of employing membrane processes to separate and recover

Influence of fertilizer draw solution properties on the process performance and microbial community structure in a side-stream anaerobic fertilizer-drawn forward osmosis - ultrafiltration bioreactor.

PubMed

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

2017-09-01

In this study, a side-stream anaerobic fertilizer-drawn forward osmosis (FDFO) and ultrafiltration (UF) membrane bioreactor (MBR) hybrid system was proposed and operated for 55days. The FDFO performance was first investigated in terms of flux decline with various fertilizers draw solution. Flux decline was very severe with all fertilizers due to the absence of aeration and the sticky property of sludge. Flux recovery by physical cleaning varied significantly amongst tested fertilizers which seriously affected biofouling in FDFO via reverse salt flux (RSF). Besides, RSF had a significant impact on nutrient accumulation in the bioreactor. These results indicated that nutrient accumulation negatively influenced the anaerobic activity. To elucidate these phenomena, bacterial and archaeal community structures were analyzed by pyrosequencing. Results showed that bacterial community structure was affected by fertilizer properties with less impact on archaeal community structure, which resulted in a reduction in biogas production and an increase in nitrogen content. Copyright © 2017 Elsevier Ltd. All rights reserved.

Removal of trace organic chemicals and performance of a novel hybrid ultrafiltration-osmotic membrane bioreactor.

PubMed

Holloway, Ryan W; Regnery, Julia; Nghiem, Long D; Cath, Tzahi Y

2014-09-16

A hybrid ultrafiltration-osmotic membrane bioreactor (UFO-MBR) was investigated for over 35 days for nutrient and trace organic chemical (TOrC) removal from municipal wastewater. The UFO-MBR system uses both ultrafiltration (UF) and forward osmosis (FO) membranes in parallel to simultaneously extract clean water from an activated sludge reactor for nonpotable (or environmental discharge) and potable reuse, respectively. In the FO stream, water is drawn by osmosis from activated sludge through an FO membrane into a draw solution (DS), which becomes diluted during the process. A reverse osmosis (RO) system is then used to reconcentrate the diluted DS and produce clean water suitable for direct potable reuse. The UF membrane extracts water, dissolved salts, and some nutrients from the system to prevent their accumulation in the activated sludge of the osmotic MBR. The UF permeate can be used for nonpotable reuse purposes (e.g., irrigation and toilet flushing). Results from UFO-MBR investigation illustrated that the chemical oxygen demand, total nitrogen, and total phosphorus removals were greater than 99%, 82%, and 99%, respectively. Twenty TOrCs were detected in the municipal wastewater that was used as feed to the UFO-MBR system. Among these 20 TOrCs, 15 were removed by the hybrid UFO-MBR system to below the detection limit. High FO membrane rejection was observed for all ionic and nonionic hydrophilic TOrCs and lower rejection was observed for nonionic hydrophobic TOrCs. With the exceptions of bisphenol A and DEET, all TOrCs that were detected in the DS were well rejected by the RO membrane. Overall, the UFO-MBR can operate sustainably and has the potential to be utilized for direct potable reuse applications.

Membrane processing technology in the food industry: food processing, wastewater treatment, and effects on physical, microbiological, organoleptic, and nutritional properties of foods.

PubMed

Kotsanopoulos, Konstantinos V; Arvanitoyannis, Ioannis S

2015-01-01

Membrane processing technology (MPT) is increasingly used nowadays in a wide range of applications (demineralization, desalination, stabilization, separation, deacidification, reduction of microbial load, purification, etc.) in food industries. The most frequently applied techniques are electrodialysis (ED), reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), and microfiltration (MF). Several membrane characteristics, such as pore size, flow properties, and the applied hydraulic pressure mainly determine membranes' potential uses. In this review paper the basic membrane techniques, their potential applications in a large number of fields and products towards the food industry, the main advantages and disadvantages of these methods, fouling phenomena as well as their effects on the organoleptic, qualitative, and nutritional value of foods are synoptically described. Some representative examples of traditional and modern membrane applications both in tabular and figural form are also provided.

Membrane treatment of Aqueous Film Forming Foam (AFFF) wastes for recovery of its active ingredients. Final report, Mar 79-Sep 80

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chian, E.S.K.; Wu, T.P.; Rowland, R.W.

1980-10-01

Ultrafiltration (UF) and Reverse Osmosis (RO) treatment of Aqueous Film Forming Foam (AFFF) solutions was investigated to determine the feasibility of employing membrane processes to separate and recover AFFF active ingredients for reuse. Studies were performed on both 6% AFFF in tap-water solutions and on actual wastewaters spiked with 3% or 6% AFFF. The AFFF materials used in this study consisted of Ansul, 3M FC-206, and 3M FC-780. Membrane employed for these studies included Abcor HFD, HFF, HFJ, and HFK tubular ultrafiltration (UF) membranes and a DuPont B-10 reverse osmosis (RO) module. Parameters monitored to represent AFFF ingredients were TOC,more » dissolved solids, surfactants, and % glycol. An attempt was also made to determine fluorocarbons as fluoride. Membrane fluxes were also determined. Results of this study demonstrate the feasibility of employing UF-RO processes to separate and recover the AFFF active ingredients for reuse. Approximately 75% recovery of the AFFF active ingredients as represented by the foam test was attained. An economic analysis of the membrane treatment processes indicates that it is extremely favorable in recovering the AFFF wastewater for reuse. Pilot-scale studies are, however, necessary to fully establish the process feasibilities and economics of the AFFF recovery system.« less

Forward Osmosis in India: Status and Comparison with Other Desalination Technologies

PubMed Central

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

Forward Osmosis in India: Status and Comparison with Other Desalination Technologies.

PubMed

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.

Reverse Osmosis Processing of Organic Model Compounds and Fermentation Broths

DTIC Science & Technology

2006-04-01

AFRL-ML-TY-TP-2007-4545 POSTPRINT REVERSE OSMOSIS PROCESSING OF ORGANIC MODEL COMPOUNDS AND FERMENTATION BROTHS Robert Diltz...TELEPHONE NUMBER (Include area code) Bioresource Technology 98 (2007) 686–695Reverse osmosis processing of organic model compounds and fermentation broths...December 2005; accepted 31 January 2006 Available online 4 April 2006Abstract Post-treatment of an anaerobic fermentation broth was evaluated using a 150

Polymers in separation processes

NASA Astrophysics Data System (ADS)

Wieszczycka, Karolina; Staszak, Katarzyna

2017-05-01

Application of polymer materials as membranes and ion-exchange resins was presented with a focus on their use for the recovery of metal ions from aqueous solutions. Several membrane techniques were described including reverse osmosis, nanofiltration, ultrafiltration, diffusion and Donnan dialysis, electrodialysis and membrane extraction system (polymer inclusion and supported membranes). Moreover, the examples of using ion-exchange resins in metal recovery were presented. The possibility of modification of the resin was discussed, including hybrid system with metal cation or metal oxide immobilized on polymer matrices or solvent impregnated resin.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 materialsmore » 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.« less

[Formation and Variation of Brominated Disinfection By-products in A Combined Ultrafiltration and Reverse Osmosis Process for Seawater Desalination].

PubMed

Yang, Zhe; Sun, Ying-xue; Shi, Na; Hu, Hong-ying

2015-10-01

The characteristics of dissolved organic matter (DOM) and brominated disinfection by-products ( Br-DBPs ) during a seawater desalination ultrafiltration (UF) combined reverse osmosis (RO) process were studied. The seawater contained high level of bromide ion (45.6-50.9 mg x L(-1)) and aromatic compounds with specific ultraviolet absorbance ( SUVA) of 3.6-6.0 L x (mg x m)(-1). The tryptophan-like aromatic protein, fulvic acid-like and soluble microbial by-product-like were the main fluorescent DOM in the seawater. After pre-chlorination of the seawater, the concentrations of DBPs was significantly increased in the influent of UF, which was dominantly the Br-DBPs. Bromoform (CHBr3) accounted for 70.48% - 91.50% of total trihalomethanes (THMs), dibromoacetic acid (Br2CHCO2H) occupied 81.14% - 100% of total haloacetic acids (HAAs) and dibromoacetonitrile (C2HBr2N) occupied 83.77% - 87.45% of total haloacetonitriles ( HANs). The removal efficiency of THMs, HAAs and HANs by the UF membrane was 36.63% - 40.39%, 73.83% - 95.38% and 100%, respectively. The RO membrane could completely remove the HAAs, while a little of the THMs was penetrated. The antiestrogenic activity in the seawater was 0.35 - 0.44 mg x L(-1), which was increased 32% - 69% after the pre-chlorination. The DBPs and other bio-toxic organics which formed during the UF-RO process were finally concentrated in the UF concentrate and RO concentrate.

Genotoxic effects of old landfill leachate on HepG2 cells after nitration/ultrafiltration/reverse osmosis membrane treatment process.

PubMed

Cheng, Rong; Zhao, Ling; Yin, Pinghe

2017-12-01

Toxicity assessment of nitration/ultrafiltration/reverse osmosis (nitration/UF/RO) project, which has recently been widely used as an efficient process with applications in practical leachate treatment, was very limited. In the present study, DNA damage of leachates was investigated before and after the nitration/UF/RO process by a battery of assays with human hepatoma cells. Methyletrazolium assay showed a high cytotoxicity of 97.1% after being exposed to the highest concentration of raw leachate for 24 h, and a cytotoxicity of 26% in effluent at a concentration of 30% (v/v). Both comet assay (24 h) and γH2AX flow cytometer assay (3 h) showed increased levels of DNA damage in cells exposed to raw leachate and after nitration/UF-treated leachate followed by a significant increase of 7-ethoxyresorufin-O-deethylase activity. However, the effluent after nitration/UF/RO treatment showed no significant difference compared to negative control for γH2AX flow cytometer assay but slight DNA damage at concentrations of 20% and 30% (v/v) as well as increase of 7-ethoxyresorufin-O-deethylase. Analysis showed that nitration/UF/RO process exhibited high removal of physicochemical indexes and significant reduction of toxic and genotoxic effects of leachate, but still demands an improvement to reduce all possible negative risks to the environment and humans. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Improvement of water desalination technologies in reverse osmosis plants

NASA Astrophysics Data System (ADS)

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 analyzed and the dependence of the output of desalinated water (permeate) through the membranes on the pressure of influent water for desalination and the dependence of the permeate output on the water viscosity and the dependence of the specific permeate output on the velocity and length of the motion of the desalination water flux were built. The values of the optimum pressure of source influent water for desalination in a reverse osmosis device were found. Provided the current prices for membrane elements (800 to 1200 USD) and cost of electricity (0.06-0.1 USD), the optimum pressure is 1.0 to 1.4 MPa.

Development of Precoat Filtration Technology for Reverse Osmosis Units

DTIC Science & Technology

1981-11-20

CONTRACT DAAK 70-79-C-0046 0 FINAL REPORT 0 DEVELOPMENT OF PRECOAT FILTRATION TECHNOLOGY FOR REVERSE OSMOSIS UNITS Submitted by: ,i JOHNS - MANVILLE SALES...NTU (Hach). The one square foot vertical leaf filter was set up at the Johns - Manville R&D Center as shown in Figure 1. A 300 gallon feed tank was

Learning about (Not by) Osmosis.

ERIC Educational Resources Information Center

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)

Nanofiltration technology in water treatment and reuse: applications and costs.

PubMed

Shahmansouri, Arash; Bellona, Christopher

2015-01-01

Nanofiltration (NF) is a relatively recent development in membrane technology with characteristics that fall between ultrafiltration and reverse osmosis (RO). While RO membranes dominate the seawater desalination industry, NF is employed in a variety of water and wastewater treatment and industrial applications for the selective removal of ions and organic substances, as well as certain niche seawater desalination applications. The purpose of this study was to review the application of NF membranes in the water and wastewater industry including water softening and color removal, industrial wastewater treatment, water reuse, and desalination. Basic economic analyses were also performed to compare the profitability of using NF membranes over alternative processes. Although any detailed cost estimation is hampered by some uncertainty (e.g. applicability of estimation methods to large-scale systems, labor costs in different areas of the world), NF was found to be a cost-effective technology for certain investigated applications. The selection of NF over other treatment technologies, however, is dependent on several factors including pretreatment requirements, influent water quality, treatment facility capacity, and treatment goals.

Supported microporous ceramic membranes

DOEpatents

Webster, Elizabeth; Anderson, Marc

1993-01-01

A method for permformation of microporous ceramic membranes onto a porous support includes placing a colloidal suspension of metal or metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane useful for ultrafiltration, reverse osmosis, or molecular sieving having mean pore sizes less than 100 Angstroms.

Metal oxide membranes for gas separation

DOEpatents

Anderson, Marc A.; Webster, Elizabeth T.; Xu, Qunyin

1994-01-01

A method for permformation of a microporous ceramic membrane onto a porous support includes placing a colloidal suspension of metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane having mean pore sizes less than 30 Angstroms and useful for ultrafiltration, reverse osmosis, or gas separation.

Supported microporous ceramic membranes

DOEpatents

Webster, E.; Anderson, M.

1993-12-14

A method for the formation of microporous ceramic membranes onto a porous support includes placing a colloidal suspension of metal or metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane useful for ultrafiltration, reverse osmosis, or molecular sieving having mean pore sizes less than 100 Angstroms. 4 figures.

Metal oxide membranes for gas separation

DOEpatents

Anderson, M.A.; Webster, E.T.; Xu, Q.

1994-08-30

A method for formation of a microporous ceramic membrane onto a porous support includes placing a colloidal suspension of metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane having mean pore sizes less than 30 Angstroms and useful for ultrafiltration, reverse osmosis, or gas separation. 4 figs.

Isolation and chemical characterization of dissolved and colloidal organic matter

USGS Publications Warehouse

Aiken, G.; Leenheer, J.

1993-01-01

Commonly used techniques for the concentration and isolation of organic matter from water, such as preparative chromatography, ultrafiltration and reverse osmosis, and the methods used to analyze the organic matter obtained by these methods are reviewed. The development of methods to obtain organic matter that is associated with fractions of the dissolved organic carbon other than humic substances, such as organic bases, hydrophilic organic acids and colloidal organic matter are discussed. Methods specifically used to study dissolved organic nitrogen and dissolved organic phosphorous are also discussed. -from Authors

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

EPA Science Inventory

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

ECUT: Energy Conversion and Utilization Technologies program biocatalysis research activity. Potential membrane applications to biocatalyzed processes: Assessment of concentration polarization and membrane fouling

NASA Technical Reports Server (NTRS)

Ingham, J. D.

1983-01-01

Separation and purification of the products of biocatalyzed fermentation processes, such as ethanol or butanol, consumes most of the process energy required. Since membrane systems require substantially less energy for separation than most alternatives (e.g., distillation) they have been suggested for separation or concentration of fermentation products. This report is a review of the effects of concentration polarization and membrane fouling for the principal membrane processes: microfiltration, ultrafiltration, reverse osmosis, and electrodialysis including a discussion of potential problems relevant to separation of fermentation products. It was concluded that advanced membrane systems may result in significantly decreased energy consumption. However, because of the need to separate large amounts of water from much smaller amounts of product that may be more volatile than wate, it is not clear that membrane separations will necessarily be more efficient than alternative processes.

Research Regarding Membrane Filtration Capacity of Water Collected from Siret River

NASA Astrophysics Data System (ADS)

Mihalache, I.; Pintilie, Ş. C.; Bîrsan, I. G.; Dănăila, E.; Baltă, Ş.

2018-06-01

In the past decade, the high demand and strict legislations regarding pure and potable water production and quality require finding new treatment technologies with higher effectiveness. When compared with conventional treatment technologies, membrane technology is a viable option in water and wastewater treatment due to high performance, ease in implementation, cost-efficiency among other advantages, also, leading to a rapid expansion in use in almost all areas of industry. Polymeric ultrafiltration membranes have been successfully used in various industries since 1969, and in later years they were studied in the water purification sector, mainly as a pre-treatment step to reduce severe fouling that could occur in reverse osmosis filtration stage. Polysulfone (PSf) was the polymer of choice in this study with two concentrations, 25 wt.% and 30 wt.%. Surface SEM morphology, roughness and water affinity were analyzed for the studied membranes. Water from Siret river was used in the permeation tests in order to analyze the retention capacity and anti-fouling ability. The present study revealed higher retention for the 30 wt.% PSf membranes, from the physico-chemical and microbiological point-of-view and lower fouling, also.

Sustainability assessment of tertiary wastewater treatment technologies: a multi-criteria analysis.

PubMed

Plakas, K V; Georgiadis, A A; Karabelas, A J

2016-01-01

The multi-criteria analysis gives the opportunity to researchers, designers and decision-makers to examine decision options in a multi-dimensional fashion. On this basis, four tertiary wastewater treatment (WWT) technologies were assessed regarding their sustainability performance in producing recycled wastewater, considering a 'triple bottom line' approach (i.e. economic, environmental, and social). These are powdered activated carbon adsorption coupled with ultrafiltration membrane separation (PAC-UF), reverse osmosis, ozone/ultraviolet-light oxidation and heterogeneous photo-catalysis coupled with low-pressure membrane separation (photocatalytic membrane reactor, PMR). The participatory method called simple multi-attribute rating technique exploiting ranks was employed for assigning weights to selected sustainability indicators. This sustainability assessment approach resulted in the development of a composite index as a final metric, for each WWT technology evaluated. The PAC-UF technology appears to be the most appropriate technology, attaining the highest composite value regarding the sustainability performance. A scenario analysis confirmed the results of the original scenario in five out of seven cases. In parallel, the PMR was highlighted as the technology with the least variability in its performance. Nevertheless, additional actions and approaches are proposed to strengthen the objectivity of the final results.

Fouling of nanofiltration, reverse osmosis, and ultrafiltration membranes by protein mixtures: the role of inter-foulant-species interaction.

PubMed

Wang, Yi-Ning; Tang, Chuyang Y

2011-08-01

Protein fouling of nanofiltration (NF), reverse osmosis (RO), and ultrafiltration (UF) membranes by bovine serum albumin (BSA), lysozyme (LYS), and their mixture was investigated under cross-flow conditions. The effect of solution chemistry, membrane properties, and permeate flux level was systematically studied. When the solution pH was within the isoelectric points (IEPs) of the two proteins (i.e., pH 4.7-10.4), the mixed protein system experienced more severe flux decline compared to the respective single protein systems, which may be attributed to the electrostatic attraction between the negatively charged BSA and positively charged LYS molecules. Unlike a typical single protein system, membrane fouling by BSA-LYS mixture was only weakly dependent on solution pH within this pH range, and increased ionic strength was found to enhance the membrane flux as a result of the suppressed BSA-LYS electrostatic attraction. Membrane fouling was likely controlled by foulant-fouled-membrane interaction under severe fouling conditions (elevated flux level and unfavorable solution chemistry that promotes fouling), whereas it was likely dominated by foulant-clean-membrane interaction under mild fouling conditions. Compared to nonporous NF and RO membranes, the porous UF membrane was more susceptible to dramatic flux decline due to the increased risk of membrane pore plugging. This study reveals that membrane fouling by mixed macromolecules may behave very differently from that by typical single foulant system, especially when the inter-foulant-species interaction dominates over the intra-species interaction in the mixed foulant system.

On the Recent Use of Membrane Technology for Olive Mill Wastewater Purification

PubMed Central

Ochando-Pulido, Javier Miguel; Martinez-Ferez, Antonio

2015-01-01

Many reclamation treatments as well as integrated processes for the purification of olive mill wastewaters (OMW) have already been proposed and developed but not led to completely satisfactory results, principally due to complexity or cost-ineffectiveness. The olive oil industry in its current status, composed of little and dispersed factories, cannot stand such high costs. Moreover, these treatments are not able to abate the high concentration of dissolved inorganic matter present in these highly polluted effluents. In the present work, a review on the actual state of the art concerning the treatment and disposal of OMW by membranes is addressed, comprising microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO), as well as membrane bioreactors (MBR) and non-conventional membrane processes such as vacuum distillation (VD), osmotic distillation (OD) and forward osmosis (FO). Membrane processes are becoming extensively used to replace many conventional processes in the purification of water and groundwater as well as in the reclamation of wastewater streams of very diverse sources, such as those generated by agro-industrial activities. Moreover, a brief insight into inhibition and control of fouling by properly-tailored pretreatment processes upstream the membrane operation and the use of the critical and threshold flux theories is provided. PMID:26426062

Application of reverse osmosis in purifying drinking water

NASA Astrophysics Data System (ADS)

Jiang, Lei; Tu, Yue; Li, Xiangmin; Li, Haixiang

2018-06-01

In view of the shortage of water resources and the pollution of water environment, the development of efficient water purification technology is one of the effective ways to ensure the safety of drinking water. The technology of reverse osmosis has attracted much attention in the application of drinking water security for its advantages of no phase change and simple equipment. This paper briefly introduces the research progress at home and abroad, basic principles, process flow diagram, advantages and disadvantages and development direction of the technology.

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

USDA-ARS?s Scientific Manuscript database

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...

Manufacturing polymer thin films in a micro-gravity environment

NASA Technical Reports Server (NTRS)

Vera, Ivan

1987-01-01

This project represents Venezuela's first scientific experiment in space. The apparatus for the automatic casting of two polymer thin films will be contained in NASA's Payload No. G-559 of the Get Away Special program for a future orbital space flight in the U.S. Space Shuttle. Semi-permeable polymer membranes have important applications in a variety of fields, such as medicine, energy, and pharmaceuticals and in general fluid separation processes, such as reverse osmosis, ultrafiltration, and electrodialysis. The casting of semi-permeable membranes in space will help to identify the roles of convection in determining the structure of these membranes.

Enhanced attrition bioreactor for enzyme hydrolysis of cellulosic materials

DOEpatents

Scott, Timothy C.; Scott, Charles D.; Faison, Brendlyn D.; Davison, Brian H.; Woodward, Jonathan

1997-01-01

A process for converting cellulosic materials, such as waste paper, into fuels and chemicals, such as sugars and ethanol, utilizing enzymatic hydrolysis of the major carbohydrate of paper: cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. An attritor and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. Additionally, microfiltration, ultrafiltration and reverse osmosis steps are included to further increase reaction efficiency. The resulting sugars are converted to a dilute product in a fluidized-bed bioreactor utilizing a biocatalyst, such as microorganisms. The dilute product is then concentrated and purified.

Solvent-resistant microporous polymide membranes

DOEpatents

Miller, W.K.; McCray, S.B.; Friesen, D.T.

1998-03-10

An asymmetric microporous membrane with exceptional solvent resistance and highly desirable permeability is disclosed. The membrane is made by a solution-casting or solution-spinning process from a copolyamic acid comprising the condensation reaction product in a solvent of at least three reactants selected from certain diamines and dianhydrides and post-treated to imidize and in some cases cross-link the copolyamic acid. The membrane is useful as an uncoated membrane for ultrafiltration, microfiltration, and membrane contactor applications, or may be used as a support for a permselective coating to form a composite membrane useful in gas separations, reverse osmosis, nanofiltration, pervaporation, or vapor permeation.

Solvent-resistant microporous polymide membranes

DOEpatents

Miller, Warren K.; McCray, Scott B.; Friesen, Dwayne T.

1998-01-01

An asymmetric microporous membrane with exceptional solvent resistance and highly desirable permeability is disclosed. The membrane is made by a solution-casting or solution-spinning process from a copolyamic acid comprising the condensation reaction product in a solvent of at least three reactants selected from certain diamines and dianhydrides and post-treated to imidize and in some cases cross-link the copolyamic acid. The membrane is useful as an uncoated membrane for ultrafiltration, microfiltration, and membrane contactor applications, or may be used as a support for a permselective coating to form a composite membrane useful in gas separations, reverse osmosis, nanofiltration, pervaporation, or vapor permeation.

Enhanced attrition bioreactor for enzyme hydrolysis or cellulosic materials

DOEpatents

Scott, Timothy C.; Scott, Charles D.; Faison, Brendlyn D.; Davison, Brian H.; Woodward, Jonathan

1996-01-01

A process for converting cellulosic materials, such as waste paper, into fuels and chemicals, such as sugars and ethanol, utilizing enzymatic hydrolysis of the major carbohydrate of paper: cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. An attritor and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. Additionally, microfiltration, ultrafiltration and reverse osmosis steps are included to further increase reaction efficiency. The resulting sugars are converted to a dilute product in a fluidized-bed bioreactor utilizing a biocatalyst, such as microorganisms. The dilute product is then concentrated and purified.

Occurrence of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in N.E. Spanish surface waters and their removal in a drinking water treatment plant that combines conventional and advanced treatments in parallel lines.

PubMed

Flores, Cintia; Ventura, Francesc; Martin-Alonso, Jordi; Caixach, Josep

2013-09-01

Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are two emerging contaminants that have been detected in all environmental compartments. However, while most of the studies in the literature deal with their presence or removal in wastewater treatment, few of them are devoted to their detection in treated drinking water and fate during drinking water treatment. In this study, analyses of PFOS and PFOA have been carried out in river water samples and in the different stages of a drinking water treatment plant (DWTP) which has recently improved its conventional treatment process by adding ultrafiltration and reverse osmosis in a parallel treatment line. Conventional and advanced treatments have been studied in several pilot plants and in the DWTP, which offers the opportunity to compare both treatments operating simultaneously. From the results obtained, neither preoxidation, sand filtration, nor ozonation, removed both perfluorinated compounds. As advanced treatments, reverse osmosis has proved more effective than reverse electrodialysis to remove PFOA and PFOS in the different configurations of pilot plants assayed. Granular activated carbon with an average elimination efficiency of 64±11% and 45±19% for PFOS and PFOA, respectively and especially reverse osmosis, which was able to remove ≥99% of both compounds, were the sole effective treatment steps. Trace levels of PFOS (3.0-21 ng/L) and PFOA (<4.2-5.5 ng/L) detected in treated drinking water were significantly lowered in comparison to those measured in precedent years. These concentrations represent overall removal efficiencies of 89±22% for PFOA and 86±7% for PFOS. Copyright © 2013 Elsevier B.V. All rights reserved.

Preparation and assessment of carboxylate polyelectrolyte as draw solute for forward osmosis.

PubMed

Cui, Hongtao; Zhang, Hanmin; Jiang, Wei; Yang, Fenglin

2018-02-01

Reverse draw solute diffusion not only reduces the water flux in forward osmosis (FO), but also contaminates the feed solution and eventually increases the regeneration cost of draw solution. In the present study, a new polyelectrolyte was synthesized as FO draw solute to address this problem. Acrylic acid and sodium p-styrenesulfonate monomers with hydrophilic group were used to fabricate carboxylate polyelectrolyte through free radical polymerization reaction. Results demonstrated that the osmotic pressure of carboxylate polyelectrolyte solution had a good linear relationship with concentration, and the viscosity of 0.18 g/mL solution was less than 5.4 cP. Active layer facing draw solution produced the initial water flux of 11.77 LMH and active layer facing feed solution yielded the initial water flux of 6.68 LMH when the concentration of draw solution was 0.18 g/mL. The reverse solute flux was around 1 gMH, and specific reverse solute flux of 0.18 g/mL carboxylate polyelectrolyte draw solution was 0.11 g/L which was much lower than that of traditional inorganic salts. Finally, diluted draw solution was regenerated via ultrafiltration, and the recovery efficiency of 94.78% was achieved. So, carboxylate polyelectrolyte can be suitable draw solute for FO.

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

PubMed Central

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

Polymers.

ERIC Educational Resources Information Center

Tucker, David C.

1986-01-01

Presents an open-ended experiment which has students exploring polymer chemistry and reverse osmosis. This activity involves construction of a polymer membrane, use of it in a simple osmosis experiment, and application of its principles in solving a science-technology-society problem. (ML)

Model-Based Extracted Water Desalination System for Carbon Sequestration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dees, Elizabeth M.; Moore, David Roger; Li, Li

Over the last 1.5 years, GE Global Research and Pennsylvania State University defined a model-based, scalable, and multi-stage extracted water desalination system that yields clean water, concentrated brine, and, optionally, salt. The team explored saline brines that ranged across the expected range for extracted water for carbon sequestration reservoirs (40,000 up to 220,000 ppm total dissolved solids, TDS). In addition, the validated the system performance at pilot scale with field-sourced water using GE’s pre-pilot and lab facilities. This project encompassed four principal tasks, in addition to Project Management and Planning: 1) identify a deep saline formation carbon sequestration site andmore » a partner that are suitable for supplying extracted water; 2) conduct a techno-economic assessment and down-selection of pre-treatment and desalination technologies to identify a cost-effective system for extracted water recovery; 3) validate the downselected processes at the lab/pre-pilot scale; and 4) define the scope of the pilot desalination project. Highlights from each task are described below: Deep saline formation characterization The deep saline formations associated with the five DOE NETL 1260 Phase 1 projects were characterized with respect to their mineralogy and formation water composition. Sources of high TDS feed water other than extracted water were explored for high TDS desalination applications, including unconventional oil and gas and seawater reverse osmosis concentrate. Technoeconomic analysis of desalination technologies Techno-economic evaluations of alternate brine concentration technologies, including humidification-dehumidification (HDH), membrane distillation (MD), forward osmosis (FO), turboexpander-freeze, solvent extraction and high pressure reverse osmosis (HPRO), were conducted. These technologies were evaluated against conventional falling film-mechanical vapor recompression (FF-MVR) as a baseline desalination process. Furthermore, a quality function deployment (QFD) method was used to compare alternate high TDS desalination technologies to FF-MVR. High pressure reverse osmosis was found to a be a promising alternative desalination technology. A deep-dive technoeconomic analysis of HPRO was performed, including Capex and Opex estimates, for seawater RO (SWRO). Additionally, two additional cases were explored: 1) a comparison of a SWRO plus HPRO system to the option of doubling the size of a standard seawater RO system to achieve the same total pure water recovery rate; and 2) a flue gas desulfurization wastewater treatment zero-liquid discharge (ZLD) application, where preconcentration with RO (SWRO or SWRO + HPRO) before evaporation and crystallization was compared to FF-MVR and crystallization technologies without RO preconcentration. Pre-pilot process validation Pre-pilot-scale tests were conducted using field production water to validate key process steps for extracted water pretreatment. Approximately 5,000 gallons of field produced water was processed through, microfiltration, ultrafiltration, and steam regenerable sorbent operations. Smaller quantities were processed through microclarification. In addition, analytical methods (purge-and-trap gas chromatography and Hach TOC analytical methods) were validated. Lab-scale HPRO elements were constructed and tested at high pressures, to identify and mitigate technical risks of the technology. Lastly, improvements in RO membrane materials were identified as the necessary next step to achieve further improvement in element performance at high pressure. Scope of Field Pilot A field pilot for extracted water pretreatment was designed.« less

Enhanced attrition bioreactor for enzyme hydrolysis or cellulosic materials

DOEpatents

Scott, T.C.; Scott, C.D.; Faison, B.D.; Davison, B.H.; Woodward, J.

1996-04-16

A process is described for converting cellulosic materials, such as waste paper, into fuels and chemicals, such as sugars and ethanol, utilizing enzymatic hydrolysis of the major carbohydrate of paper: cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. An attritor and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. Additionally, microfiltration, ultrafiltration and reverse osmosis steps are included to further increase reaction efficiency. The resulting sugars are converted to a dilute product in a fluidized-bed bioreactor utilizing a biocatalyst, such as microorganisms. The dilute product is then concentrated and purified. 1 fig.

Enhanced attrition bioreactor for enzyme hydrolysis of cellulosic materials

DOEpatents

Scott, T.C.; Scott, C.D.; Faison, B.D.; Davison, B.H.; Woodward, J.

1997-06-10

A process is described for converting cellulosic materials, such as waste paper, into fuels and chemicals, such as sugars and ethanol, utilizing enzymatic hydrolysis of the major carbohydrate of paper: cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. An attritor and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. Additionally, microfiltration, ultrafiltration and reverse osmosis steps are included to further increase reaction efficiency. The resulting sugars are converted to a dilute product in a fluidized-bed bioreactor utilizing a biocatalyst, such as microorganisms. The dilute product is then concentrated and purified. 1 fig.

Membrane technology for sustainable treated wastewater reuse: agricultural, environmental and hydrological considerations.

PubMed

Oron, Gideon; Gillerman, Leonid; Bick, Amos; Manor, Yossi; Buriakovsky, Nisan; Hagin, Joseph

2008-01-01

Field experiments were conducted in agricultural fields in which secondary wastewater of the City of Arad (Israel) is reused for irrigation. For sustainable agricultural production and safe groundwater recharge the secondary effluent is further polished by a combined two-stage membrane pilot system. The pilot membrane system consists of two main in row stages: Ultrafiltration (UF) and Reverse Osmosis (RO). The UF stage is efficient in the removal of the pathogens and suspended organic matter while the successive RO stage provides safe removal of the dissolved solids (salinity). Effluents of various qualities were applied for agricultural irrigation along with continuous monitoring of the membrane system performance. Best agricultural yields were obtained when applying effluent having minimal content of dissolved solids (after the RO stage) as compared with secondary effluent without any further treatment and extended storage. In regions with shallow groundwater reduced soil salinity in the upper productive layers, maintained by extra membrane treatment, will guarantee minimal dissolved solids migration to the aquifers and minimize salinisation processes. (c) IWA Publishing 2008.

Novel Functional Whey-Based Drinks with Great Potential in the Dairy Industry

PubMed Central

Pereira, Carlos; Gomes, David; Gomez-Zavaglia, Andrea; de Antoni, Graciela

2015-01-01

Summary This work focuses on the production of liquid whey protein concentrates by ultrafiltration followed by thermal denaturation and homogenization of the ultrafiltrated concentrate, as well as on the production of ultrafiltrated permeates concentrated by reverse osmosis. Kefir grains (fresh and thawed) and/or commercial probiotic bacteria were inoculated in both liquid whey protein concentrates and concentrated ultrafiltrated permeates and grown at 25 °C for 24 h for the manufacture of fermented drinks. The physicochemical characterization (pH, titratable acidity, viscosity, and content of total solids, ash, fat and proteins) of the obtained drinks was then assessed and compared. Enumeration of viable microorganisms was carried out immediately after inoculation (at 0 h), during the fermentation period (at 12 and 24 h) and during refrigerated storage (at 48, 168 and 336 h). The fermented drinks showed acceptable physicochemical and sensorial properties, and contained above 7 log CFU/mL of lactococci and lactobacilli and 6 log CFU/mL of yeasts after 14 days of refrigerated storage, which is in agreement with the standards required by international organizations like European Food Safety Authority (EFSA) and Food and Drug Administration (FDA) for products containing probiotics. In summary, the strategy developed in this work contributes to the expansion of the applications of products derived from whey fractionation for the design of novel functional foods. PMID:27904362

Novel Functional Whey-Based Drinks with Great Potential in the Dairy Industry.

PubMed

Pereira, Carlos; Henriques, Marta; Gomes, David; Gomez-Zavaglia, Andrea; de Antoni, Graciela

2015-09-01

This work focuses on the production of liquid whey protein concentrates by ultrafiltration followed by thermal denaturation and homogenization of the ultrafiltrated concentrate, as well as on the production of ultrafiltrated permeates concentrated by reverse osmosis. Kefir grains (fresh and thawed) and/or commercial probiotic bacteria were inoculated in both liquid whey protein concentrates and concentrated ultrafiltrated permeates and grown at 25 °C for 24 h for the manufacture of fermented drinks. The physicochemical characterization (pH, titratable acidity, viscosity, and content of total solids, ash, fat and proteins) of the obtained drinks was then assessed and compared. Enumeration of viable microorganisms was carried out immediately after inoculation (at 0 h), during the fermentation period (at 12 and 24 h) and during refrigerated storage (at 48, 168 and 336 h). The fermented drinks showed acceptable physicochemical and sensorial properties, and contained above 7 log CFU/mL of lactococci and lactobacilli and 6 log CFU/mL of yeasts after 14 days of refrigerated storage, which is in agreement with the standards required by international organizations like European Food Safety Authority (EFSA) and Food and Drug Administration (FDA) for products containing probiotics. In summary, the strategy developed in this work contributes to the expansion of the applications of products derived from whey fractionation for the design of novel functional foods.

Succinate Functionalization of Hyperbranched Polyglycerol-Coated Magnetic Nanoparticles as a Draw Solute During Forward Osmosis.

PubMed

Yang, Hee-Man; Choi, Hye Min; Jang, Sung-Chan; Han, Myeong Jin; Seo, Bum-Kyoung; Moon, Jei-Kwon; Lee, Kune-Woo

2015-10-01

Hyperbranched polyglycerol-coated magnetic nanoparticles (SHPG-MNPs) were functionalized with succinate groups to form a draw solute for use in a forward osmosis (FO). After the one-step synthesis of hyperbranched polyglycerol-coated magnetic nanoparticles (HPG-MNPs), the polyglycerol groups on the surfaces of the HPG-MNPs were functionalized with succinic anhydride moieties. The resulting SHPG-MNPs showed no change of size and magnetic property compared with HPG-MNPs and displayed excellent dispersibility in water up to the concentration of 400 g/L. SHPG-MNPs solution showed higher osmotic pressure than that of HPG-MNPs solution due to the presence of surface carboxyl groups in SHPG-MNPs and could draw water from a feed solution across an FO membrane without any reverse draw solute leakage during FO process. Moreover, the water flux remained nearly constant over several SHPG-MNP darw solute regeneration cycles applied to the ultrafiltration (UF) process. The SHPG-MNPs demonstrate strong potential for use as a draw solute in FO processes.

Inland Treatment of the Brine Generated from Reverse Osmosis Advanced Membrane Wastewater Treatment Plant Using Epuvalisation System

PubMed Central

Qurie, Mohannad; Abbadi, Jehad; Scrano, Laura; Mecca, Gennaro; Bufo, Sabino A.; Khamis, Mustafa; Karaman, Rafik

2013-01-01

The reverse osmosis (RO) brine generated from the Al-Quds University wastewater treatment plant was treated using an epuvalisation system. The advanced integrated wastewater treatment plant included an activated sludge unit, two consecutive ultrafiltration (UF) membrane filters (20 kD and 100 kD cutoffs) followed by an activated carbon filter and a reverse osmosis membrane. The epuvalisation system consisted of salt tolerant plants grown in hydroponic channels under continuous water flowing in a closed loop system, and placed in a greenhouse at Al-Quds University. Sweet basil (Ocimum basilicum) plants were selected, and underwent two consecutive hydroponic flowing stages using different brine-concentrations: an adaptation stage, in which a 1:1 mixture of brine and fresh water was used; followed by a functioning stage, with 100% brine. A control treatment using fresh water was included as well. The experiment started in April and ended in June (2012). At the end of the experiment, analysis of the effluent brine showed a remarkable decrease of electroconductivity (EC), PO43−, chemical oxygen demand (COD) and K+ with a reduction of 60%, 74%, 70%, and 60%, respectively, as compared to the influent. The effluent of the control treatment showed 50%, 63%, 46%, and 90% reduction for the same parameters as compared to the influent. Plant growth parameters (plant height, fresh and dry weight) showed no significant difference between fresh water and brine treatments. Obtained results suggest that the epuvalisation system is a promising technique for inland brine treatment with added benefits. The increasing of channel number or closed loop time is estimated for enhancing the treatment process and increasing the nutrient uptake. Nevertheless, the epuvalisation technique is considered to be simple, efficient and low cost for inland RO brine treatment. PMID:23823802

Novel technologies for reverse osmosis concentrate treatment: a review.

PubMed

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.

A review of polymeric membranes and processes for potable water reuse

PubMed Central

Warsinger, David M.; Chakraborty, Sudip; Tow, Emily W.; Plumlee, Megan H.; Bellona, Christopher; Loutatidou, Savvina; Karimi, Leila; Mikelonis, Anne M.; Achilli, Andrea; Ghassemi, Abbas; Padhye, Lokesh P.; Snyder, Shane A.; Curcio, Stefano; Vecitis, Chad; Arafat, Hassan A.; Lienhard, John H.

2018-01-01

Conventional water resources in many regions are insufficient to meet the water needs of growing populations, thus reuse is gaining acceptance as a method of water supply augmentation. Recent advancements in membrane technology have allowed for the reclamation of municipal wastewater for the production of drinking water, i.e., potable reuse. Although public perception can be a challenge, potable reuse is often the least energy-intensive method of providing additional drinking water to water stressed regions. A variety of membranes have been developed that can remove water contaminants ranging from particles and pathogens to dissolved organic compounds and salts. Typically, potable reuse treatment plants use polymeric membranes for microfiltration or ultrafiltration in conjunction with reverse osmosis and, in some cases, nanofiltration. Membrane properties, including pore size, wettability, surface charge, roughness, thermal resistance, chemical stability, permeability, thickness and mechanical strength, vary between membranes and applications. Advancements in membrane technology including new membrane materials, coatings, and manufacturing methods, as well as emerging membrane processes such as membrane bioreactors, electrodialysis, and forward osmosis have been developed to improve selectivity, energy consumption, fouling resistance, and/or capital cost. The purpose of this review is to provide a comprehensive summary of the role of polymeric membranes in the treatment of wastewater to potable water quality and highlight recent advancements in separation processes. Beyond membranes themselves, this review covers the background and history of potable reuse, and commonly used potable reuse process chains, pretreatment steps, and advanced oxidation processes. Key trends in membrane technology include novel configurations, materials and fouling prevention techniques. Challenges still facing membrane-based potable reuse applications, including chemical and biological contaminant removal, membrane fouling, and public perception, are highlighted as areas in need of further research and development. PMID:29937599

Utilization of membranes for H2O recycle system

NASA Technical Reports Server (NTRS)

Ohya, H.; Oguchi, M.

1986-01-01

Conceptual studies of closed ecological life support systems (CELSS) carried out at NAL in Japan for a water recycle system using membranes are reviewed. The system will treat water from shower room, urine, impure condensation from gas recycle system, and so on. The H2O recycle system is composed of prefilter, ultrafiltration membrane, reverse osmosis membrane, and distillator. Some results are shown for a bullet train of toilet-flushing water recycle equipment with an ultraviltration membrane module. The constant value of the permeation rate with a 4.7 square meters of module is about 70 1/h after 500th of operation. Thermovaporization with porous polytetrafluorocarbon membrane is also proposed to replce the distillator.

Online monitoring of N-nitrosodimethylamine rejection as a performance indicator of trace organic chemical removal by reverse osmosis.

PubMed

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.

Performance of electrodialysis reversal and reverse osmosis for reclaiming wastewater from high-tech industrial parks in Taiwan: A pilot-scale study.

PubMed

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.

Rotating carbon nanotube membrane filter for water desalination

NASA Astrophysics Data System (ADS)

Tu, Qingsong; Yang, Qiang; Wang, Hualin; Li, Shaofan

2016-05-01

We have designed a porous nanofluidic desalination device, a rotating carbon nanotube membrane filter (RCNT-MF), for the reverse osmosis desalination that can turn salt water into fresh water. The concept as well as design strategy of RCNT-MF is modeled, and demonstrated by using molecular dynamics simulation. It has been shown that the RCNT-MF device may significantly improve desalination efficiency by combining the centrifugal force propelled reverse osmosis process and the porous CNT-based fine scale selective separation technology.

Rotating carbon nanotube membrane filter for water desalination

PubMed Central

Tu, Qingsong; Yang, Qiang; Wang, Hualin; Li, Shaofan

2016-01-01

We have designed a porous nanofluidic desalination device, a rotating carbon nanotube membrane filter (RCNT-MF), for the reverse osmosis desalination that can turn salt water into fresh water. The concept as well as design strategy of RCNT-MF is modeled, and demonstrated by using molecular dynamics simulation. It has been shown that the RCNT-MF device may significantly improve desalination efficiency by combining the centrifugal force propelled reverse osmosis process and the porous CNT-based fine scale selective separation technology. PMID:27188982

Cleaner Landfills

NASA Technical Reports Server (NTRS)

2000-01-01

Osmotek, Inc. developed the Direct Osmosis treatment system through SBIR funding from Ames Research Center. Using technology originally developed for flight aboard the Space Station, the company brought it to their commercial water purification treatment system, Direct Osmosis. This water purification system uses a direct osmosis process followed by a reverse osmosis treatment. Because the product extracts water from a waste product, Osmotek is marketing the unit for use in landfills. The system can treat leachate (toxic chemicals leached into a water source), by filtering the water and leaving behind the leahcate. The leachate then becomes solidified into substance that can not seep into water.

The casting and mechanism of formation of semi-permeable polymer membranes in a microgravity environment

NASA Astrophysics Data System (ADS)

Vera, I.

The National Electric Company of Venezuela, C.A.D.A.F.E., is sponsoring the development of this experiment which represents Venezuela's first scientific experiment in space. The apparatus for the automatic casting of polymer thin films will be contained in NASA's payload No. G-559 of the Get Away Special program for a future orbital space flight in the U.S. Space Shuttle. Semi-permeable polymer membranes have important applications in a variety of fields, such as medecine, energy, and pharmaceuticals, and in general fluid separation processes such as reverse osmosis, ultra-filtration, and electro-dialysis. The casting of semi-permeable membranes in space will help to identify the roles of convection in determining the strucutre of these membranes.

Rapid evaluation of reverse-osmosis membranes

NASA Technical Reports Server (NTRS)

Hollahan, J. R.; Wydeven, T.

1972-01-01

Simultaneous reverse-osmosis tests conducted with centrifuges having multiple compartment heads are discussed. Equipment for retaining reverse-osmosis membrane is illustrated. Method of conducting tests is described.

Addressing reverse osmosis fouling within water reclamation--a side-by-side comparison of low-pressure membrane pretreatments.

PubMed

Kent, Fraser C; Farahbakhsh, Khosrow

2011-06-01

A tertiary membrane filtration (TMF) pilot operating on secondary effluent and a membrane bioreactor (MBR) were setup in a side-by-side study as pretreatments for two identical reverse osmosis pilot systems. The water quality of the permeate from both low-pressure membrane pretreatment systems and the fouling rate of the reverse osmosis systems were compared to assess the capabilities of the two low-pressure membrane pretreatments to prevent organic fouling of the reverse osmosis systems. Both pretreatment pilots were setup using typical operating conditions (i.e., solids retention time and mixed-liquor suspended solids). A consistent difference in water quality and reverse osmosis performance was demonstrated during the 12-month study. The MBR permeate consistently had significantly lower total organic carbon (TOC) and chemical oxygen demand concentrations, but higher color and specific UV absorbance compared with the permeate from the TMF pretreatment. The pretreatment with the MBR gave an average reverse osmosis fouling rate over the entire study (0.27 Lmh/bar.month) that was less than half of the value found for the reverse osmosis with TMF pretreatment (0.60 Lmh/bar.month). A correlation of reverse osmosis feed TOC concentration with average reverse osmosis fouling rate also was established, independent of the pretreatment method used. Results from a cleaning analysis, energy dispersive spectroscopy, and fourier transformed infrared reflectometry confirmed that the foulants were primarily organic in nature. It is concluded that, for this type of application and setup, MBR systems present an advantage over tertiary membrane polishing of secondary effluent for reverse osmosis pretreatment.

Downstream processing of reverse osmosis brine: Characterisation of potential scaling compounds.

PubMed

Zaman, Masuduz; Birkett, Greg; Pratt, Christopher; Stuart, Bruce; Pratt, Steven

2015-09-01

Reverse osmosis (RO) brine produced at a full-scale coal seam gas (CSG) water treatment facility was characterized with spectroscopic and other analytical techniques. A number of potential scalants including silica, calcium, magnesium, sulphates and carbonates, all of which were present in dissolved and non-dissolved forms, were characterized. The presence of spherical particles with a size range of 10-1000 nm and aggregates of 1-10 microns was confirmed by transmission electron microscopy (TEM). Those particulates contained the following metals in decreasing order: K, Si, Sr, Ca, B, Ba, Mg, P, and S. Characterization showed that nearly one-third of the total silicon in the brine was present in the particulates. Further, analysis of the RO brine suggested supersaturation and precipitation of metal carbonates and sulphates during the RO process should take place and could be responsible for subsequently capturing silica in the solid phase. However, the precipitation of crystalline carbonates and sulphates are complex. X-ray diffraction analysis did not confirm the presence of common calcium carbonates or sulphates but instead showed the presence of a suite of complex minerals, to which amorphous silica and/or silica rich compounds could have adhered. A filtration study showed that majority of the siliceous particles were less than 220 nm in size, but could still be potentially captured using a low molecular weight ultrafiltration membrane. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

PubMed

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 water permeability, the total water cost could be further reduced. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electrochemical treatment of concentrate from reverse osmosis of sanitary landfill leachate.

PubMed

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

2016-10-01

Conventional sanitary landfill leachate treatment has recently been complemented and, in some cases, completely replaced by reverse osmosis technology. Despite the good quality of treated water, the efficiency of the process is low and a large volume of reverse osmosis concentrate has to be either discharged or further treated. In this study, the use of anodic oxidation combined with electro-Fenton processes to treat the concentrate obtained in the reverse osmosis of sanitary landfill leachate was evaluated. The anodic oxidation pretreatment was performed in a pilot plant using an electrochemical cell with boron-doped diamond electrodes. In the electro-Fenton experiments, a boron-doped diamond anode and carbon-felt cathode were used, and the influence of the initial pH and iron concentration were studied. For the experimental conditions, the electro-Fenton assays performed at an initial pH of 3 had higher organic load removal levels, whereas the best nitrogen removal was attained when the electrochemical process was performed at the natural pH of 8.8. The increase in the iron concentration had an adverse impact on treatment under natural pH conditions, but it enhanced the nitrogen removal in the electro-Fenton assays performed at an initial pH of 3. The combined anodic oxidation and electro-Fenton process is useful for treating the reverse osmosis concentrate because it is effective at removing the organic load and nitrogen-containing species. Additionally, this process potentiates the increase in the biodegradability index of the treated effluent. Copyright © 2016 Elsevier Ltd. All rights reserved.

Unlocking High-Salinity Desalination with Cascading Osmotically Mediated Reverse Osmosis: Energy and Operating Pressure Analysis.

PubMed

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.

Major advances in concentrated and dry milk products, cheese, and milk fat-based spreads.

PubMed

Henning, D R; Baer, R J; Hassan, A N; Dave, R

2006-04-01

Advances in dairy foods and dairy foods processing since 1981 have influenced consumers and processors of dairy products. Consumer benefits include dairy products with enhanced nutrition and product functionality for specific applications. Processors convert raw milk to finished product with improved efficiencies and have developed processing technologies to improve traditional products and to introduce new products for expanding the dairy foods market. Membrane processing evolved from a laboratory technique to a major industrial process for milk and whey processing. Ultra-filtration and reverse osmosis have been used extensively in fractionation of milk and whey components. Advances in cheese manufacturing methods have included mechanization of the making process. Membrane processing has allowed uniform composition of the cheese milk and starter cultures have become more predictable. Cheese vats have become larger and enclosed as well as computer controlled. Researchers have learned to control many of the functional properties of cheese by understanding the role of fat and calcium distribution, as bound or unbound, in the cheese matrix. Processed cheese (cheese, foods, spreads, and products) maintain their importance in the industry as many product types can be produced to meet market needs and provide stable products for an extended shelf life. Cheese delivers concentrated nutrients of milk and bio-active peptides to consumers. The technologies for the production of concentrated and dried milk and whey products have not changed greatly in the last 25 yr. The size and efficiencies of the equipment have increased. Use of reverse osmosis in place of vacuum condensing has been proposed. Modifying the fatty acid composition of milkfat to alter the nutritional and functional properties of dairy spread has been a focus of research in the last 2 decades. Conjugated linoleic acid, which can be increased in milkfat by alteration of the cow's diet, has been reported to have anticancer, anti-atherogenic, antidiabetic, and antiobesity effects for human health. Separating milk fat into fractions has been accomplished to provide specific fractions to improve butter spreadability, modulate chocolate meltability, and provide texture for low-fat cheeses.

Monolith filter apparatus and membrane apparatus, and method using same

DOEpatents

Goldsmith, Robert L [Wayland, MA

2012-04-03

A filtration apparatus that separates a liquid feedstock mixed with a gas into filtrate and retentate, the apparatus including at least one filtration device comprised of at least one monolith segment of porous material that defines a plurality of passageways extending longitudinally from a feed face of the structure to a retentate end face. The filtration device contains at least one filtrate conduit within it for carrying filtrate toward a filtrate collection zone, the filtrate conduit providing a path of lower flow resistance than that of alternative flow paths through the porous material of the device. The filtration device can also be utilized as a membrane support for a device for microfiltration, ultrafiltration, nanofiltration, reverse osmosis, or pervaporation. Also disclosed is a method for using such a filtration apparatus.

[Bacterial biofilms on PVC tubing's inner surface of hemodialysis water treatment system].

PubMed

Yang, Sha; Jia, Ke; Peng, Youming; Liu, Hong; Liu, Yinghong; Chen, Xing; Liu, Fuyou

2009-10-01

To determine the morphology, bacteria and endotoxin content of biofilms on the inner surface of PVC tubes in hemodialysis water treatment system. We dissolved biofilms of segments before and after reverse osmosis machine for bacterial count and identification. We studied biofilm structure of segments before and after reverse osmosis machine with eyes and scanning electron microscope. Biofilms of all 7 segments were dissolved for qualitative and quantitative assay of endotoxin. The inner surface of segment before reverse osmosis machine was homogeneously distributed with activated carbon powder deposition. The segment after reverse osmosis machine was normal. With scanning electron microscope, biofilm with successive surface and sandwich was found on the inner surface of segment before reverse osmosis machine, formed by clustering bacillus, activated carbon powder and some coccus. Bacteria of the same shape and length were found on segment after reverse osmosis machine, but fewer and looser. Bacterial culture and identification showed the former was mostly gram-negative bacillus, the latter was only a few micrococcus. Endotoxin of biofilm was between 2.0 EU/mL and 4.0 EU/mL. Quantitative assay showed: segment after softener (2.821+/-0.807) EU/mL; segment after active charcoal canister(3.635+/-0.427) EU/mL; segment before reverse osmosis machine (3.687+/-0.271) EU/mL; segment after reverse osmosis machine (2.041+/-0.295) EU/mL; exit of power pump (1.983+/-0.390)EU/mL;the 1st dead space (2.373+/-0.535) EU/mL; and the 2nd dead space (2.858+/-0.690)EU/mL. Biofilms are found on the inner surface of segment before and after reverse osmosis machine. Endotoxin level from high to low is as follows: segment before reverse osmosis machine, segment after active charcoal canister, the 2nd dead space, segment after softener, the 1st dead space, segment after reverse osmosis machine, exit of power pump. The character of the bacteria and endotoxin of the biofilm can help us find better ways to control them.

MULTIPLE CONTAMINANT ISSUES AND TECHNOLOGIES

EPA Science Inventory

The presentation provides information on the removal of arsenic with either nitrate, uranium, radium, radon and antimony as a co-contaminant. The technologies discussed as having the capability of removing arsenic and one of the other contaminants are reverse osmosis, anion and ...

Cascade Reverse Osmosis Air Conditioning System: Cascade Reverse Osmosis and the Absorption Osmosis Cycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

BEETIT Project: Battelle is developing a new air conditioning system that uses a cascade reverse osmosis (RO)-based absorption cycle. Analyses show that this new cycle can be as much as 60% more efficient than vapor compression, which is used in 90% of air conditioners. Traditional vapor-compression systems use polluting liquids for a cooling effect. Absorption cycles use benign refrigerants such as water, which is absorbed in a salt solution and pumped as liquid—replacing compression of vapor. The refrigerant is subsequently separated from absorbing salt using heat for re-use in the cooling cycle. Battelle is replacing thermal separation of refrigerant withmore » a more efficient reverse osmosis process. Research has shown that the cycle is possible, but further investment will be needed to reduce the number of cascade reverse osmosis stages and therefore cost.« less

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

EPA Science Inventory

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...

Review on the fate of organic micropollutants in wastewater treatment and water reuse with membranes.

PubMed

Siegrist, H; Joss, A

2012-01-01

A brief review of the fate of micropollutants in membrane-based wastewater treatment due to sorption, stripping, biological degradation/transformation and membrane separation is discussed, to give an overview of these technologies due to the growing importance for water reuse purposes. Compared with conventional activated sludge treatment (CAS) micropollutant removal in membrane bioreactor (MBR) is slightly improved due to complete suspended solids removal and increased sludge age. For discharge to sensitive receiving waters advanced treatment, such as post-ozonation or activated carbon adsorption, is recommended. In water reuse plants nanofiltration (NF) and reverse osmosis (RO) efficiently reject micropollutants due to size exclusions as well as electrostatic and hydrophobic effects reaching potable quality. To remove micropollutants fully, additionally post-ozone or the addition of powdered activated carbon (PAC) have to be applied, which in parallel also reduce NDMA precursors. The concentrate has to be treated if disposed to sensitive receiving waters due to its high micropollutant concentration and ecotoxicity potential. The present review summarizes principles and capabilities for the most important membrane-based applications for wastewater treatment, i.e. porous membranes in MBRs (micro- or ultrafiltration) and dense membrane applications (NF and RO) for water reuse.

Novel industrial wastewater treatment integrated with recovery of water and salt under a zero liquid discharge concept.

PubMed

Rajamani, Sengodagounder

2016-03-01

Conventional industrial effluent treatment systems are designed to reduce biochemical oxygen demand (BOD), chemical oxygen demand (COD) but not total dissolved solids (TDS), mainly contributed by chlorides. In addition to the removal of TDS, it is necessary to recover water for reuse to meet the challenges of shortage of quality water. To recover water, the wastewater needs to be further treated by adopting treatment systems including microfilters, low pressure membrane units such as ultrafiltration (UF), membrane bioreactors (MBR), etc., for the application of reverse osmosis (RO) systems. By adopting the RO system, 75%-80% of quality water with <500 mg/L of TDS is recovered from treated effluent. The management of 20%-25% of the saline water rejected from the RO system with high TDS concentration is being addressed by methods such as forced evaporation systems. The recovery of water from domestic and industrial waste for reuse has become a reality. The membrane system has been used for different applications. It has become mandatory to achieve zero liquid discharge (ZLD) in many states in India and other countries such as Spain, China, etc., and resulted in development of new treatment technologies to suit the local conditions.

Rotating Reverse-Osmosis for Water Purification

NASA Technical Reports Server (NTRS)

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.

Energy-efficient membrane separations in the sweetener industry. Final report for Phase I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babcock, W.C.

1984-02-14

The objective of the program is to investigate the use of membrane processes as energy-efficient alternatives to conventional separation processes in current use in the corn sweetener industry. Two applications of membranes were studied during the program: (1) the concentration of corn steep water by reverse osmosis; and (2) the concentration of dilute wastes called sweetwater with a combination of reverse osmosis and a process known as countercurrent reverse osmosis. Laboratory experiments were conducted for both applications, and the results were used to conduct technical and economic analyses of the process. It was determined that the concentration of steep watermore » by reverse osmosis plus triple-effect evaporation offers savings of a factor of 2.5 in capital costs and a factor of 4.5 in operating costs over currently used triple-effect evaporation. In the concentration of sweetwater by reverse osmosis and countercurrent reverse osmosis, capital costs would be about the same as those for triple-effect evaporation, but operating costs would be only about one-half those of triple-effect evaporation.« less

Removal of precursors and disinfection by-products (DBPs) by membrane filtration from water; a review.

PubMed

Zazouli, Mohammad Ali; Kalankesh, Laleh R

2017-01-01

Disinfection by-products (DBPs) have heterogeneous structures which are suspected carcinogens as a result of reactions between NOMs (Natural Organic Matter) and oxidants/disinfectants such as chlorine. Because of variability in DBPs characteristics, eliminate completely from drinking water by single technique is impossible. The current article reviews removal of the precursors and DBPs by different membrane filtration methods such as Microfiltration (MF), Ultrafiltration (UF), Nanofiltration (NF) and Reverse Osmosis (RO) techniques. Also, we provide an overview of existing and potentially Membrane filtration techniques, highlight their strengths and drawbacks. MF membranes are a suitable alternative to remove suspended solids and colloidal materials. However, NOMs fractions are effectively removed by negatively charged UF membrane. RO can remove both organic and inorganic DBPs and precursors simultaneously. NF can be used to remove compounds from macromolecular size to multivalent ions.

Recent developments in membrane-based separations in biotechnology processes: review.

PubMed

Rathore, A S; Shirke, A

2011-01-01

Membrane-based separations are the most ubiquitous unit operations in biotech processes. There are several key reasons for this. First, they can be used with a large variety of applications including clarification, concentration, buffer exchange, purification, and sterilization. Second, they are available in a variety of formats, such as depth filtration, ultrafiltration, diafiltration, nanofiltration, reverse osmosis, and microfiltration. Third, they are simple to operate and are generally robust toward normal variations in feed material and operating parameters. Fourth, membrane-based separations typically require lower capital cost when compared to other processing options. As a result of these advantages, a typical biotech process has anywhere from 10 to 20 membrane-based separation steps. In this article we review the major developments that have occurred on this topic with a focus on developments in the last 5 years.

Effects of Wastewater from Oil Exploration on Soil Mesofauna.

PubMed

Ferreira, Raimundo N C; Weber, Olmar B; Correia, Maria E F; Benazzi-Ikeda, Eloísa S; Scoriza, Rafael N; Mesquita, Antonio L M

2015-12-01

Wastewater from oil exploration may contain substances that can alter the diversity of soil organisms. This study evaluated whether produced water treated by filtration or reverse osmosis and glutaraldehyde from reverse osmosis treatments negatively affected the mesofauna in an irrigated area. In the field, irrigation with produced water treated by reverse osmosis and filtration influenced Hymenoptera and Cosmochthonius sp., while Entomobryomorpha springtails were affected only by the reverse osmosis water. In the ecotoxicological tests, reproduction in the springtail Folsomia candida was inhibited by the reverse osmosis treatment, while reproduction in the earthworm Enchytraeus crypticus was affected by both water treatments. Although glutaraldehyde did not affect the survival of F. candida, the reproduction was inhibited (EC50 = 44.4 mg/L). No adverse effect of glutaraldehyde was observed on reproduction or survival of E. crypticus. These results indicate that produced water, when used in irrigated agriculture, may affect soil functional mesofauna.

Reverse Osmosis Optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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 tomore » 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.¬« less

Reverse Osmosis Optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

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 tomore » 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.« less

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

PubMed

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

2018-03-01

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

ECLSS evolution: Advanced instrumentation interface requirements. Volume 3: Appendix C

NASA Technical Reports Server (NTRS)

1991-01-01

An Advanced ECLSS (Environmental Control and Life Support System) Technology Interfaces Database was developed primarily to provide ECLSS analysts with a centralized and portable source of ECLSS technologies interface requirements data. The database contains 20 technologies which were previously identified in the MDSSC ECLSS Technologies database. The primary interfaces of interest in this database are fluid, electrical, data/control interfaces, and resupply requirements. Each record contains fields describing the function and operation of the technology. Fields include: an interface diagram, description applicable design points and operating ranges, and an explaination of data, as required. A complete set of data was entered for six of the twenty components including Solid Amine Water Desorbed (SAWD), Thermoelectric Integrated Membrane Evaporation System (TIMES), Electrochemical Carbon Dioxide Concentrator (EDC), Solid Polymer Electrolysis (SPE), Static Feed Electrolysis (SFE), and BOSCH. Additional data was collected for Reverse Osmosis Water Reclaimation-Potable (ROWRP), Reverse Osmosis Water Reclaimation-Hygiene (ROWRH), Static Feed Solid Polymer Electrolyte (SFSPE), Trace Contaminant Control System (TCCS), and Multifiltration Water Reclamation - Hygiene (MFWRH). A summary of the database contents is presented in this report.

Evaluation of alternatives for best available technology treatment and retreatment of uranium-contaminated solutions at the Paducah Gaseous Diffusion Plant C-400 Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Del Cul, G.D.

1991-02-01

The Paducah Gaseous Diffusion Plant C-400 Decontamination Facility generators aqueous solutions that originate in drum washing, machine parts and equipment cleaning, and other decontamination processes. In general, the waste contains uranyl, fluoride, carbonate, and nitrate ions, in addition to soaps, detergents, secondary contaminants, and particulate matter. The main contaminants are fluoride, technetium, uranium, and other heavy metals. In accordance with Department of Energy (DOE) Order 5400.5, the releases of radioactive materials must be as low as reasonably achievable and be below the derived concentration guide limits. To comply with the DOE order, an action plan was formulated. The action planmore » included a literature search to support best available technology evaluation of treatment alternatives, a quality assurance/quality control plan, suggestion of alternative treatment options, bench-scale test studies of the proposed treatment alternatives, and establishment of the final recommendation. Five major technologies were considered: precipitation/coprecipitation, reverse osmosis, ultrafiltration, supported liquid membranes, and ion exchange. Biosorption was also briefly considered. Based on C-400's requirements and facilities, the precipitation/coprecipitation process appears to be the best suited for use at the plant. Four different treatment options using the precipitation/coprecipitation technology were proposed. Bench-scale studies of all four options were suggested. Options 1 and 2 represent a combination of lime-softening and iron coprecipitation. Laboratory test evaluations were initiated and the results involving Options 1 and 2 reported here. 29 refs., 1 fig., 2 tabs.« less

Chemical treatment of commercial reverse osmosis membranes for use in FO

EPA Science Inventory

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...

Membrane filtration of olive mill wastewater and exploitation of its fractions.

PubMed

Paraskeva, C A; Papadakis, V G; Kanellopoulou, D G; Koutsoukos, P G; Angelopoulos, K C

2007-04-01

Olive mill wastewater (OMW) produced from small units scattered in rural areas of Southern Europe is a major source of pollution of surface and subsurface water. In the present work, a treatment scheme based on physical separation methods is presented. The investigation was carried out using a pilot-plant unit equipped with ultrafiltration, nanofiltration, and reverse osmosis membranes. Approximately 80% of the total volume of wastewater treated by the membrane units was sufficiently cleaned to meet the standards for irrigation water. The concentrated fractions collected in the treatment concentrates were characterized by high organic load and high content of phenolic compounds. The concentrates were tested in hydroponic systems to examine their toxicity towards undesired herbs. The calculations of the cost of the overall process showed that fixed and operational costs could be recovered from the exploitation of OMW byproducts as water for irrigation and/or as bioherbicides.

Study of using microfiltration and reverse osmosis membrane technologies for reclaiming cooling water in the power industry.

PubMed

Li, J; Xu, Z Y; An, H G; Liu, L Q

2007-07-01

A study of using dual membrane technologies, microfiltration (MF) and reverse osmosis (RO), for reclaiming blowdown of the cooling tower was conducted at ZJK power plant, Hebei province, China. The study shows that the combined MF-RO system can effectively reduce water consumption in the power industry. The results indicate that MF process is capable of producing a filtrate suitable for RO treatment and achieving a silt density index (SDI) less than 2, turbidity of 0.2 NTU. The water quality of RO effluent is very good with an average conductivity of about 40 micros/cm and rejection of 98%. The product water is suitable for injection into the cooling tower to counteract with cooling water intrusion. After adopting this system, water-saving effectiveness as expressed in terms of cycles of concentration could be increased from 2.5-2.8 times to 5 times.

Some Results Bearing on the Value of Improvements of Membranes for Reverse Osmosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamont, A

2006-03-08

This analysis evaluates the potential economic benefits that could result from the improvements in the permeability of membranes for reverse osmosis. The discussion provides a simple model of the operation of a reverse osmosis plant. It examines the change in the operation that might result from improvements in the membrane and computes the cost of water as a function of the membrane permeability.

High pressure rotating reverse osmosis for long term space missions

NASA Astrophysics Data System (ADS)

Christensen Pederson, Cynthia Lynn

Rotating reverse osmosis, which uses reverse osmosis to purify water and rotating filtration to improve the efficacy of filtration, has great potential for wastewater recycling on a long term space mission. Previous investigations of a proof-of-concept device indicated that the most efficient method to improve rotating reverse osmosis performance is to increase the operational pressure. Thus, a second generation device and fluid circuit were designed, fabricated, and tested to permit high pressure operation for long time periods. The design overcame several obstacles including membrane attachment, rotating seal design, and fluid and pressure management. A theoretical model of rotating reverse osmosis was modified to properly account for the flow conditions in the new design. Tests lasting a week were conducted with a variety of model wastewaters. Significant fouling and a decrease in flux were observed after three days of testing regardless of the operational parameters. A semi-empirical model, the fouling potential, was added to the theoretical model to account for the fouling. This allowed the simulation of 48 hour cleaning cycles that significantly increased the flux of the device. Experimental investigation of the rotational speed and concentrate flow rate indicated that an increase in either parameter decreased the fouling slightly. A week long test of a wastewater ersatz with a biocide did not exhibit a decrease in flux around day three that otherwise occurred. Therefore, biofouling was identified as the primary mechanism of fouling. Rotating reverse osmosis was compared with conventional spiral wound reverse osmosis and displayed increased rejection under dead end filtration conditions. The rotating device exhibited similar rejection and increased flux compared to a tubular reverse osmosis device previously used in a NASA wastewater recovery system. The integration of the rotating device into a NASA water recovery management system was evaluated. Lastly, a theoretical model of rotating hemofiltration was developed that demonstrated that the device is not clinically feasible given the permeability of available hemofiltration membranes.

Advantages and application of forward osmosis

USDA-ARS?s Scientific Manuscript database

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...

Exceptionally fast water desalination at complete salt rejection by pristine graphyne monolayers.

PubMed

Xue, Minmin; Qiu, Hu; Guo, Wanlin

2013-12-20

Desalination that produces clean freshwater from seawater holds the promise of solving the global water shortage for drinking, agriculture and industry. However, conventional desalination technologies such as reverse osmosis and thermal distillation involve large amounts of energy consumption, and the semipermeable membranes widely used in reverse osmosis face the challenge to provide a high throughput at high salt rejection. Here we find by comprehensive molecular dynamics simulations and first principles modeling that pristine graphyne, one of the graphene-like one-atom-thick carbon allotropes, can achieve 100% rejection of nearly all ions in seawater including Na(+), Cl(-), Mg(2+), K(+) and Ca(2+), at an exceptionally high water permeability about two orders of magnitude higher than those for commercial state-of-the-art reverse osmosis membranes at a salt rejection of ~98.5%. This complete ion rejection by graphyne, independent of the salt concentration and the operating pressure, is revealed to be originated from the significantly higher energy barriers for ions than for water. This intrinsic specialty of graphyne should provide a new possibility for the efforts to alleviate the global shortage of freshwater and other environmental problems.

Energy-efficient membrane separations in the sweetener industry. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ray, R.J.

1986-02-14

Objective was to investigate the use of membrane processes as energy-efficient alternatives to certain conventional separation processes now in use in the corn-sweetener industry. Three applications of membranes were studied during the program: the concentration of corn steep water by reverse osmosis; the concentration of dilute wastes, called ''sweetwater,'' by a combination of reverse osmosis and countercurrent reverse osmosis; and the enrichment of corn syrup in fructose by a process involving selective complexation of fructose by membrane filtration. Laboratory experiments were conducted for all three applications, and the results were used to conduct technical and economic analyses of the process.more » Calculations indicate that the use of reverse osmosis in combination with conventional mechanical-vapor-recompression evaporation to concentrate steep water, offers savings of a factor of 2.5 in capital costs and a factor of 4.5 in operating costs over currently used evaporation alone. In the concentration of sweetwater by reverse osmosis and countercurrent reverse osmosis, capital costs would be about the same as those for evaporation, but operating costs would only be about one-half those of evaporation. For the fructose-enrichment scheme, preliminary results indicate that the savings in energy alone for the membrane process would be about $0.01/lb of sweetener produced by the process, or about $20 million annually, for the corn-sweetener industry.« less

Evaluation of alternatives for best available technology treatment and retreatment of uranium-contaminated wastewater at the Paducah Gaseous Diffusion Plant C-400 Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Del Cul, G.D.; Osborne, P.E.; Beck, D.E.

1991-01-01

The Paducah Gaseous Diffusion Plant (PGDP) C-400 Decontamination Facility generates aqueous solutions that originate in drum washing, machine parts and equipment cleaning, and other decontamination processes. The chemical composition of the waste depends on the particular operation involved. In general, the waste contains uranyl, fluoride, carbonate, and nitrate ions, plus soaps, detergents, secondary contaminants, and particulate matter. The uranium content is rather variable ranging between 0.5 and 30 g/l. The main contaminants are fluoride, technetium, uranium, and other heavy metals. The plan included (1) a literature search to support best available technology (BAT) evaluation of treatment alternatives, (2) a qualitymore » assurance/quality control plan, (3) suggestion of alternative treatment options, (4) bench-scale tests studies of the proposed treatment alternatives, and (5) establishment of the final recommendation. The following report records the evaluation of items (1) to (3) of the action plan for the BAT evaluation of alternatives for the treatment and retreatment of uranium-contaminated wastewater at the PGDP C-400 treatment facility. After a thorough literature search, five major technologies were considered: (1) precipitation/coprecipitation, (2) reverse osmosis, (3) ultrafiltration, (4) supported liquid membranes, and (5) ion exchange. Biosorption was also considered, but as it is a fairly new technology with few demonstrations of its capabilities, it is mentioned only briefly in the report. Based on C-400's requirements and facilities, the precipitation/coprecipitation process appears to be the best suited for use at the plant. Four different treatment options using the precipitation/coprecipitation technology are proposed. Bench-scale studies of the four options are suggested. 37 refs.« less

Novel Membranes and Systems for Industrial and Municipal Water Purification and Reuse

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

This factsheet describes a project that developed nano-engineered, high-permeance membrane materials with more than double the permeance of current reverse osmosis membranes as well as manufacturing technologies for large-scale production of the novel materials.

Optimal design of reverse osmosis module networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maskan, F.; Wiley, D.E.; Johnston, L.P.M.

2000-05-01

The structure of individual reverse osmosis modules, the configuration of the module network, and the operating conditions were optimized for seawater and brackish water desalination. The system model included simple mathematical equations to predict the performance of the reverse osmosis modules. The optimization problem was formulated as a constrained multivariable nonlinear optimization. The objective function was the annual profit for the system, consisting of the profit obtained from the permeate, capital cost for the process units, and operating costs associated with energy consumption and maintenance. Optimization of several dual-stage reverse osmosis systems were investigated and compared. It was found thatmore » optimal network designs are the ones that produce the most permeate. It may be possible to achieve economic improvements by refining current membrane module designs and their operating pressures.« less

Reverse-osmosis membranes by plasma polymerization

NASA Technical Reports Server (NTRS)

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.

Review: Water recovery from brines and salt-saturated solutions: operability and thermodynamic efficiency considerations for desalination technologies

PubMed Central

Vane, Leland M.

2017-01-01

BACKGROUND When water is recovered from a saline source, a brine concentrate stream is produced. Management of the brine stream can be problematic, particularly in inland regions. An alternative to brine disposal is recovery of water and possibly salts from the concentrate. RESULTS This review provides an overview of desalination technologies and discusses the thermodynamic efficiencies and operational issues associated with the various technologies particularly with regard to high salinity streams. CONCLUSION Due to the high osmotic pressures of the brine concentrates, reverse osmosis, the most common desalination technology, is impractical. Mechanical vapor compression which, like reverse osmosis, utilizes mechanical work to operate, is reported to have the highest thermodynamic efficiency of the desalination technologies for treatment of salt-saturated brines. Thermally-driven processes, such as flash evaporation and distillation, are technically able to process saturated salt solutions, but suffer from low thermodynamic efficiencies. This inefficiency could be offset if an inexpensive source of waste or renewable heat could be used. Overarching issues posed by high salinity solutions include corrosion and the formation of scales/precipitates. These issues limit the materials, conditions, and unit operation designs that can be used. PMID:29225395

Review: Water recovery from brines and salt-saturated solutions: operability and thermodynamic efficiency considerations for desalination technologies.

PubMed

Vane, Leland M

2017-03-08

When water is recovered from a saline source, a brine concentrate stream is produced. Management of the brine stream can be problematic, particularly in inland regions. An alternative to brine disposal is recovery of water and possibly salts from the concentrate. This review provides an overview of desalination technologies and discusses the thermodynamic efficiencies and operational issues associated with the various technologies particularly with regard to high salinity streams. Due to the high osmotic pressures of the brine concentrates, reverse osmosis, the most common desalination technology, is impractical. Mechanical vapor compression which, like reverse osmosis, utilizes mechanical work to operate, is reported to have the highest thermodynamic efficiency of the desalination technologies for treatment of salt-saturated brines. Thermally-driven processes, such as flash evaporation and distillation, are technically able to process saturated salt solutions, but suffer from low thermodynamic efficiencies. This inefficiency could be offset if an inexpensive source of waste or renewable heat could be used. Overarching issues posed by high salinity solutions include corrosion and the formation of scales/precipitates. These issues limit the materials, conditions, and unit operation designs that can be used.

Arsenic and Antimony Removal from Drinking Water by Point-of-Entry Reverse Osmosis Coupled with Dual Plumbing Distribution - U.S. EPA Demonstration Project at Carmel Elementary School in Carmel, ME -Final Performance Evaluation Report

EPA Science Inventory

This report documents the activities performed for and the results obtained from the arsenic and antimony removal treatment technology demonstration project at the Carmel Elementary School (CES) in Carmel, ME. An innovative approach of employing point of entry (POE) reverse osmo...

DEMONSTRATION OF BULLETIN: DISC TUBE™ MODULE TECHNOLOGY ROCHEM SEPARATION SYSTEMS, INC.

EPA Science Inventory

The Rochem Disc Tube™ Module System uses membrane separation to treat aqueous solutions ranging from seawater to leachate contaminated with organic solvents. The system uses reverse osmosis through a semipermeable membrane to separate purified water from contaminated liquids. Osm...

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

PubMed

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

2016-11-15

Arsenic contamination of groundwater is posing a serious challenge to drinking water supplies on a global scale. In India and Bangladesh, arsenic has caused the most serious public health issue in the world for nearly two decades. The aim of this work was to study an arsenic removal system based on reverse osmosis at pilot scale treating two different water sources from two different locations in the State of Bihar, India. For this purpose two villages, Bind Toli and Ramnagar in the Patna District were selected, both located very close to the river Ganga. The trials were conducted with aerated and non-aerated groundwater. It is the first time that the arsenic removal efficiency for aerated and non-aerated groundwater by reverse osmosis technology in combination with an energy-saving recovery system have been studied. As the principle of reverse osmosis requires a relatively high pressure, its energy demand is naturally high. By using an energy recovery system, this demand can be lowered, leading to an energy demand per liter permeate of 3-4Wh/L only. Due to high iron levels in the groundwater and as a consequence the precipitation of ferric (hydr)oxides, it was necessary to develop a granular media filter for the trials under aeration in order to protect the membrane from clogging. Two different materials, first locally available sand, and second commercially available anthracite were tested in the granular media filter. For the trials with aerated groundwater, total arsenic removal efficiency at both locations was around 99% and the arsenic concentration in permeate was in compliance with the WHO and National Indian Standard of 10μg/L. However, trials under anoxic conditions with non-aerated groundwater could not comply with this standard. Additionally a possible safe discharge of the reverse osmosis concentrate into an abandoned well was studied. It was observed that re-injection of reject water underground may offer a safe disposal option. However, long-term hydrogeological studies need to be conducted for confirmation. Copyright © 2016 Elsevier B.V. All rights reserved.

High-performance multi-functional reverse osmosis membranes obtained by carbon nanotube·polyamide nanocomposite

PubMed Central

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

Compatibility Study of Nanofiltration and Reverse Osmosis Membranes with 1 Cyclohexylpiperidenium Bicarbonate Solutions

DOE Data Explorer

Adhikari, Birendra; Jones, Michael G.; Orme, Christopher J.; Wendt, Daniel S.; Wilson, Aaron D.

2015-10-01

The switchable polarity solvent forward osmosis (SPS FO) desalination process requires use of a polishing filtration step to remove trace quantities of draw solution from the product water stream. Selected nanofiltration (NF) and reverse osmosis (RO) membranes were tested for their ability to recover water from 1-cyclohexylpiperidenium bicarbonate solutions in this application. This submission includes the experimental data used to calculate NF and RO membrane flux-normalized net driving pressure (FNNDP) and flux-normalized rejection (FNR) performance in recovering water from 1-cyclohexylpiperidenium bicarbonate solutions. This data is further described and visualized in the manuscript entitled "Compatibility study of nanofiltration and reverse osmosis membranes with 1 cyclohexylpiperidenium bicarbonate solutions" (see attached Compatibility Study Manuscript).

Inorganic fouling mitigation by salinity cycling in batch reverse osmosis.

PubMed

Warsinger, David M; Tow, Emily W; Maswadeh, Laith A; Connors, Grace B; Swaminathan, Jaichander; Lienhard V, John H

2018-06-15

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 batch and continuous (conventional) reverse osmosis systems to the nucleation induction times for crystallization of sparingly soluble salts. This study considers the inorganic foulants calcium sulfate (gypsum), calcium carbonate (calcite), and silica, and the work predicts maximum recovery ratios for the treatment of typical water sources using batch reverse osmosis (BRO) and continuous reverse osmosis. The prediction method is validated through comparisons to the measured time delay for CaSO 4 membrane scaling in a bench-scale, recirculating reverse osmosis unit. The maximum recovery ratio for each salt solution (CaCO 3 , CaSO 4 ) is individually predicted as a function of inlet salinity, as shown in contour plots. Next, the maximum recovery ratios of batch and conventional RO are compared across several water sources, including seawater, brackish groundwater, and RO brine. Batch RO's shorter residence times, associated with cycling from low to high salinity during each batch, enable significantly higher recovery ratios and higher salinity than in continuous RO for all cases examined. Finally, representative brackish RO brine samples were analyzed to determine the maximum possible recovery with batch RO. Overall, the induction time modeling methodology provided here can be used to allow batch RO to operate at high salinity and high recovery, while controlling scaling. The results show that, in addition to its known energy efficiency improvement, batch RO has superior inorganic fouling resistance relative to conventional RO. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

NASA Technical Reports Server (NTRS)

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

1974-01-01

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

40 CFR 141.62 - Maximum contaminant levels for inorganic contaminants.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 501-3,300, 3,301-10,000. Oxidation/Filtration 7 All size categories. Reverse Osmosis (centralized) 6 501-3,300, 3,301-10,000. Reverse Osmosis (Point-of-Use) 4 All size categories. 1 Section 1412(b)(4)(E...

Stabilization of porous glass reverse-osmosis membranes

NASA Technical Reports Server (NTRS)

Ballou, E. V.; Leban, M. I.; Wydeven, T.

1972-01-01

Application of porous glass in form of capillary tubes for low capacity ion exchange in hyperfiltration experiments is discussed. Efficiency of desalination by process of reverse osmosis is described. Stabilization of porous glass membrane by presence of aluminum chloride is analyzed.

40 CFR 141.62 - Maximum contaminant levels for inorganic contaminants.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 501-3,300, 3,301-10,000. Oxidation/Filtration 7 All size categories. Reverse Osmosis (centralized) 6 501-3,300, 3,301-10,000. Reverse Osmosis (Point-of-Use) 4 All size categories. 1 Section 1412(b)(4)(E...

27 CFR 24.248 - Processes authorized for the treatment of wine, juice, and distilling material.

Code of Federal Regulations, 2010 CFR

2010-04-01

... vinous character of the wine(2) None of the stripping solution may migrate into the wine. Reverse osmosis....2910. 1 This process must be done on distilled spirits plant premises. However, reverse osmosis, under...

27 CFR 24.248 - Processes authorized for the treatment of wine, juice, and distilling material.

Code of Federal Regulations, 2014 CFR

2014-04-01

... vinous character of the wine(2) None of the stripping solution may migrate into the wine. Reverse osmosis....2910. 1 This process must be done on distilled spirits plant premises. However, reverse osmosis, under...

27 CFR 24.248 - Processes authorized for the treatment of wine, juice, and distilling material.

Code of Federal Regulations, 2011 CFR

2011-04-01

... vinous character of the wine(2) None of the stripping solution may migrate into the wine. Reverse osmosis....2910. 1 This process must be done on distilled spirits plant premises. However, reverse osmosis, under...

40 CFR 141.62 - Maximum contaminant levels for inorganic contaminants.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 501-3,300, 3,301-10,000. Oxidation/Filtration 7 All size categories. Reverse Osmosis (centralized) 6 501-3,300, 3,301-10,000. Reverse Osmosis (Point-of-Use) 4 All size categories. 1 Section 1412(b)(4)(E...

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

NASA Technical Reports Server (NTRS)

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

1972-01-01

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

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

PubMed

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

2017-01-01

As an appropriate tool, membrane process is used for desalination of brackish water, in the production of drinking water. The present study aims to investigate desalination processes of brackish water of Qom Province in Iran. This study was carried out at the central laboratory of Water and Wastewater Company of the studied area. To this aim, membrane processes, including nanofiltration (NF) and reverse osmosis (RO), separately and also their hybrid process were applied. Moreover, water physical and chemical parameters, including salinity, total dissolved solids (TDS), electric conductivity (EC), Na +1 and Cl -1 were also measured. Afterward, the rejection percent of each parameter was investigated and compared using nanofiltration and reverse osmosis separately and also by their hybrid process. The treatment process was performed by Luna domestic desalination device, which its membrane was replaced by two NF90 and TW30 membranes for nanofiltration and reverse osmosis processes, respectively. All collected brackish water samples were fed through membranes NF90-2540, TW30-1821-100(RO) and Hybrid (NF/RO) which were installed on desalination household scale pilot (Luna water 100GPD). Then, to study the effects of pressure on permeable quality of membranes, the simulation software model ROSA was applied. Results showed that percent of the salinity rejection was recorded as 50.21%; 72.82 and 78.56% in NF, RO and hybrid processes, respectively. During the study, in order to simulate the performance of nanofiltartion, reverse osmosis and hybrid by pressure drive, reverse osmosis system analysis (ROSA) model was applied. The experiments were conducted at performance three methods of desalination to remove physic-chemical parameters as percentage of rejections in the pilot plant are: in the NF system the salinity 50.21, TDS 43.41, EC 43.62, Cl 21.1, Na 36.15, and in the RO membrane the salinity 72.02, TDS 60.26, EC 60.33, Cl 43.08, Na 54.41. Also in case of the rejection in hybrid system of those parameters and ions included salinity 78.65, TDS 76.52, EC 76.42, Cl 63.95, and Na 70.91. Comparing rejection percent in three above-mentioned methods, it could be concluded that, in reverse osmosis process, ions and non-ion parameters rejection ability were rather better than nanofiltration process, and also better in hybrid compared to reverse osmosis process. The results reported in this paper indicate that the integration of membrane nanofiltration with reverse osmosis (hybrid NF/RO) can be completed by each other probably to remove salinity, TDS, EC, Cl, and Na.

Review of cost versus scale: water and wastewater treatment and reuse processes.

PubMed

Guo, Tianjiao; Englehardt, James; Wu, Tingting

2014-01-01

The US National Research Council recently recommended direct potable water reuse (DPR), or potable water reuse without environmental buffer, for consideration to address US water demand. However, conveyance of wastewater and water to and from centralized treatment plants consumes on average four times the energy of treatment in the USA, and centralized DPR would further require upgradient distribution of treated water. Therefore, information on the cost of unit treatment processes potentially useful for DPR versus system capacity was reviewed, converted to constant 2012 US dollars, and synthesized in this work. A logarithmic variant of the Williams Law cost function was found applicable over orders of magnitude of system capacity, for the subject processes: activated sludge, membrane bioreactor, coagulation/flocculation, reverse osmosis, ultrafiltration, peroxone and granular activated carbon. Results are demonstrated versus 10 DPR case studies. Because economies of scale found for capital equipment are counterbalanced by distribution/collection network costs, further study of the optimal scale of distributed DPR systems is suggested.

The casting of semi-permeable membranes in a microgravity environment

NASA Technical Reports Server (NTRS)

Vera, I.

1986-01-01

The experiment is to study polymeric membranes. Presently, semipermeable membranes are being manufactured from several different kinds of polymers all over the world and specific applications have been identified in fluid separation processes such as reverse osmosis, ultrafiltration and electrodialysis. Although, the ultrastructure of asymmetric and composite membranes have been under intensive study, still there are many questions about the factors affecting this structure and their degree of correlation. Nevertheless, there is indication that the entire morphological structure of polymeric membranes could be affected by the difference in specific gravity between the cast solution and the coagulation liquid normally used in the membranes preparation process. The casting of semipermeable membranes in space might help to identify the effect of gravity upon the structure of these membranes. It is important to recognize that the casting process involves changes of state and that in a microgravity environment, there will be a reduction on buoyancy-driven natural convection and density gradients.

Dissolved air flotation and me.

PubMed

Edzwald, James K

2010-04-01

This paper is mainly a critical review of the literature and an assessment of what we know about dissolved air flotation (DAF). A few remarks are made at the outset about the author's personal journey in DAF research, his start and its progression. DAF has been used for several decades in drinking water treatment as an alternative clarification method to sedimentation. DAF is particularly effective in treating reservoir water supplies; those supplies containing algae, natural color or natural organic matter; and those with low mineral turbidity. It is more efficient than sedimentation in removing turbidity and particles for these type supplies. Furthermore, it is more efficient in removing Giardia cysts and Cryptosporidium oocysts. In the last 20 years, fundamental models were developed that provide a basis for understanding the process, optimizing it, and integrating it into water treatment plants. The theories were tested through laboratory and pilot-plant studies. Consequently, there have been trends in which DAF pretreatment has been optimized resulting in better coagulation and a decrease in the size of flocculation tanks. In addition, the hydraulic loading rates have increased reducing the size of DAF processes. While DAF has been used mainly in conventional type water plants, there is now interest in the technology as a pretreatment step in ultrafiltration membrane plants and in desalination reverse osmosis plants. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Effective treatment of olive mill effluents from two-phase and three-phase extraction processes by batch membranes in series operation upon threshold conditions.

PubMed

Ochando-Pulido, J M; Hodaifa, G; Victor-Ortega, M D; Rodriguez-Vives, S; Martinez-Ferez, A

2013-12-15

Production of olive oil results in the generation of high amounts of heavy polluted effluents characterized by extremely variable contaminants degree, leading to sensible complexity in treatment. In this work, batch membrane processes in series comprising ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) are used to purify the effluents exiting both the two-phase and tree-phase extraction processes to a grade compatible to the discharge in municipal sewer systems in Spain and Italy. However, one main problem in applying this technology to wastewater management issues is given by membrane fouling. In the last years, the threshold flux theory was introduced as a key tool to understand fouling problems, and threshold flux measurement can give valuable information regarding optimal membrane process design and operation. In the present manuscript, mathematical approach of threshold flux conditions for membranes operation is addressed, also implementing proper pretreatment processes such as pH-T flocculation and UV/TiO2 photocatalysis with ferromagnetic-core nanoparticles in order to reduce membranes fouling. Both influence the organic matter content as well as the particle size distribution of the solutes surviving in the wastewater stream, leading, when properly applied, to reduced fouling, higher rejection and recovery values, thus enhancing the economic feasibility of the process. Copyright © 2013 Elsevier B.V. All rights reserved.

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

EPA Science Inventory

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

CAPSULE REPORT: REVERSE OSMOSIS PROCESS

EPA Science Inventory

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...

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

EPA Science Inventory

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

Evaluation of Military Field-Water Quality. Volume 8. Performance of Mobile Water-Purification Unit (MWPU) and Pretreatment Components of the 600-GPH Reverse Osmosis Water Purification Unit (ROWPU), and Consideration of Reverse Osmosis (RO) Bypass, Potable-Water Disinfection, and Water-Quality Analysis Techniques

DTIC Science & Technology

1990-05-01

Health Risks in Potential Theaters of Operation for U.S. Military Forces. The nine volumes of this study contain a comprehensive assessment of the chemical...module. The percentage of total free chlorine ( hypochlorous acid , HOCl) plus hypochlorlte ion (OClN), measured by the Model 453 membrane sensor, varies...between the performances of the 600-Sph Reverse Osmosis Water Purification Unit (ROWPU) operated in the bypass node and ’the Mobile Water Purification

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

USGS Publications Warehouse

Huff, G.F.

2006-01-01

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

The evolution of technological strategies in the prevention of dialysis water pollution: sixteen years' experience.

PubMed

Bolasco, Piergiorgio; Contu, Antonio; Meloni, Patrizia; Vacca, Dorio; Murtas, Stefano

2012-01-01

This report attempts to illustrate the positive impact on the quality of dialysis water produced over a 16-year period through the progressive optimization of technological procedures. Fundamental steps included the following: elimination of polyvinyl chloride (PVC), periodical controls, introduction of stainless steel and/or polyethylene polymer and substitution of single-pass reverse osmosis (SRO) with double-pass reverse osmosis (DRO). Daily overnight automatic thermal disinfection of distribution piping rings represented the final step. A dramatic improvement was observed in 645 water samples obtained from distribution piping. The measures applied resulted in a significant improvement of water quality, featuring levels of colony-forming units per milliliter ranging from 247.4 ± 393.7 in the presence of PVC and SRO to 14.1 ± 28.0 with stainless steel and DRO and 2.8 ± 3.2 with cross-linked polyethylene thermoplastic polymer and DRO (p < 0.01). Dialysis water should be viewed by nephrologists as a medicinal product, and every effort should be made to ensure a high-quality liquid. Copyright © 2012 S. Karger AG, Basel.

Rotating reverse osmosis: a dynamic model for flux and rejection

NASA Technical Reports Server (NTRS)

Lee, S.; Lueptow, R. M.

2001-01-01

Reverse osmosis (RO) is a compact process for the removal of ionic and organic pollutants from contaminated water. However, flux decline and rejection deterioration due to concentration polarization and membrane fouling hinders the application of RO technology. In this study, a rotating cylindrical RO membrane is theoretically investigated as a novel method to reduce polarization and fouling. A dynamic model based on RO membrane transport incorporating concentration polarization is used to predict the performance of rotating RO system. Operating parameters such as rotational speed and transmembrane pressure play an important role in determining the flux and rejection in rotating RO. For a given geometry, a rotational speed sufficient to generate Taylor vortices in the annulus is essential to maintain high flux as well as high rejection. The flux and rejection were calculated for wide range of operating pressures and rotational speeds. c 2001 Elsevier Science B.V. All rights reserved.

Water recovery from sewage using forward osmosis.

PubMed

Lutchmiah, Kerusha; Cornelissen, Emile R; Harmsen, Danny J H; Post, Jan W; Lampi, Keith; Ramaekers, Hans; Rietveld, Luuk C; Roest, Kees

2011-01-01

This research is part of the Sewer Mining project aimed at developing a new technological concept by extracting water from sewage by means of forward osmosis (FO). FO, in combination with a reconcentration system, e.g. reverse osmosis (RO) is used to recover high-quality water. Furthermore, the subsequent concentrated sewage (containing an inherent energy content) can be converted into a renewable energy (RE) source (i.e. biogas). The effectiveness of FO membranes in the recovery of water from sewage has been evaluated. Stable FO water flux values (>4.3 LMH) were obtained with primary effluent (screened, not treated) used as the feed solution. Fouling of the membrane was also induced and further investigated. Accumulated fouling was found to be apparent, but not irreversible. Sewer Mining could lead to a more economical and sustainable treatment of wastewater, facilitating the extraction of water and energy from sewage and changing the way it is perceived: not as waste, but as a resource.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shamsuddin Ilias

Fouling problems are perhaps the single most important reason for relatively slow acceptance of ultrafiltration in many areas of chemical and biological processing. To overcome the losses in permeate flux associated with concentration polarization and fouling in cross flow membrane filtration, we investigated the concept of flow reversal as a method to enhance membrane flux in ultrafiltration. Conceptually, flow reversal prevents the formation of stable hydrodynamic and concentration boundary layers at or near the membrane surface. Further more, periodic reversal of the flow direction of the feed stream at the membrane surface results in prevention and mitigation of membrane fouling.more » Consequently, these advantages are expected to enhance membrane flux significantly. A crossflow membrane filtration unit was designed and built to test the concept of periodic flow reversal for flux enhancement. The essential elements of the system include a crossflow hollow fiber membrane module integrated with a two-way valve to direct the feed flow directions. The two-way valve is controlled by a controller-timer for periodic reversal of flow of feed stream. Another important feature of the system is that with changing feed flow direction, the permeate flow direction is also changed to maintain countercurrent feed and permeate flows for enhanced mass transfer driving force (concentration difference). In this report, we report our application of Flow Reversal technique in clarification of apple juice containing pectin. The presence of pectin in apple juice makes the clarification process difficult and is believed to cause membrane fouling. Of all compounds found in apple juice, pectin is most often identified as the major hindrance to filtration performance. Based on our ultrafiltration experiments with apple juice, we conclude that under flow reversal conditions, the permeate flux is significantly enhanced when compared with the conventional unidirectional flow. Thus, flow reversal technology seems an attractive alternative to mitigate fouling problem in crossflow membrane filtration.« less

Synthesis and Characterization of Hydrophilic-Hydrophobic Poly(Arylene Ether Sulfone) Random and Segmented Copolymers for Membrane Applications

NASA Astrophysics Data System (ADS)

Nebipasagil, Ali

Poly(arylene ether sulfone)s are high-performance engineering thermoplastics that have been investigated extensively over the past several decades due to their outstanding mechanical properties, high glass transition temperatures (Tg), solvent resistance and exceptional thermal, oxidative and hydrolytic stability. Their thermal and mechanical properties are highly suited to a variety of applications including membrane applications such as reverse osmosis, ultrafiltration, and gas separation. This dissertation covers structure-property-performance relationships of poly(arylene ether sulfone) and poly(ethylene oxide)-containing random and segmented copolymers for reverse osmosis and gas separation membranes. The second chapter of this dissertation describes synthesis of disulfonated poly(arylene ether sulfone) random copolymers with oligomeric molecular weights that contain hydrophilic and hydrophobic segments for thin film composite (TFC) reverse osmosis membranes. These copolymers were synthesized and chemically modified to obtain novel crosslinkable poly(arylene ether sulfone) oligomers with acrylamide groups on both ends. The acrylamideterminated oligomers were crosslinked with UV radiation in the presence of a multifunctional acrylate and a UV initiator. Transparent, dense films were obtained with high gel fractions. Mechanically robust TFC membranes were prepared from either aqueous or water-methanol solutions cast onto a commercial UDELRTM foam support. This was the first example that utilized a water or alcohol solvent system and UV radiation to obtain reverse osmosis TFC membranes. The membranes were characterized with regard to composition, surface properties, and water uptake. Water and salt transport properties were elucidated at the department of chemical engineering at the University of Texas at Austin. The gas separation membranes presented in chapter three were poly(arylene ether sulfone) and poly(ethylene oxide) (PEO)-containing polyurethanes. Poly(arylene ether sulfone) copolymers with controlled molecular weights were synthesized and chemically modified to obtain poly(arylene ether sulfone) polyols with aliphatic hydroxyethyl terminal functionality. The hydroxyethyl-terminated oligomers and a,u-hydroxy-terminated PEO were chain extended with a diisocyanate to obtain polyurethanes. Compositions with high poly(arylene ether sulfone) content relative to the hydrophilic PEO blocks were of interest due to their mechanical integrity. The membranes were characterized to analyze their compositions, thermal and mechanical properties, water uptake, and molecular weights. These membranes were also evaluated by collaborators at the University of Texas at Austin to explore single gas transport properties. The results showed that both polymer and transport properties closely related to PEO-content. The CO2/CH4 gas selectivity of our membranes were improved from 25 to 34 and the CO2/N2 gas selectivity nearly doubled from 25 to 46 by increasing PEO-content from 0 to 30 wt.% in polyurethanes. Chapter four also focuses on polymers for gas separation membranes. Disulfonated poly(arylene ether sulfone) and poly(ethylene oxide)-containing polyurethanes were synthesized for potential applications as gas separation membranes. Disulfonated polyols containing 20 and 40 mole percent of disulfonated repeat units with controlled molecular weights were synthesized. Poly(arylene ether sulfone) polyols and alpha,o-hydroxy-terminated poly(ethylene oxide) were subsequently chain extended with a diisocyanate to obtain polyurethanes. Thermal and mechanical characterization revealed that the polyurethanes had a phase-mixed complex morphology.

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

PubMed

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

2016-07-01

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

Reverse osmosis water purification system

NASA Technical Reports Server (NTRS)

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.

Fouling reduction by ozone-enhanced backwashing process in ultrafiltration of petroleum-based oil in water emulsion

NASA Astrophysics Data System (ADS)

Aryanti, Nita; Prihatiningtyas, Indah; Kusworo, Tutuk Djoko

2017-06-01

Ultrafiltration membrane has been successfully applied for oily waste water treatment. However, one significant drawback of membrane technology is fouling which is responsible for permeate flux decline as well as reducing membrane performance. One method commonly used to reduce fouling is a backwashing process. The backwashing is carried out by a push of reversed flow from permeate side to the feed side of a membrane to remove fouling on the membrane pore and release fouling release fouling layer on the external side. However, for adsorptive fouling, the backwashing process was not effective. On the other hand, Ozone demonstrated great performance for reducing organics fouling. Hence this research was focused on backwashing process with ozone for removing fouling due to ultrafiltration of petroleum based oil emulsion. Gasoline and diesel oil were selected as dispersed phase, while as continuous phase was water added with Tween 80 as a surfactant. This research found that the Ozone backwashing was effective to improve flux recovery. In ultrafiltration of gasoline emulsion, the flux recovery after Ozone backwashing was in the range of 42-74%. For ultrafiltration of diesel oil emulsion, the permeate flux recovery was about 35-84%. In addition, foulant deposition was proposed and predicting that foulant deposition for ultrafiltration of gasoline-in-water emulsion was surfactant as the top layer and the oil was underneath the surfactant. On the other hand, for ultrafiltration of diesel oil-in-water emulsion, the oil was predicted as a top layer above the surfactant foulant.

A Mechanistic Study of Arsenic (III) Rejection by Reverse Osmosis and Nanofiltration Membranes

ERIC Educational Resources Information Center

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…

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

EPA Science Inventory

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...

Separate and Concentrate Lactic Acid Using Combination of Nanofiltration and Reverse Osmosis Membranes

NASA Astrophysics Data System (ADS)

Li, Yebo; Shahbazi, Abolghasem; Williams, Karen; Wan, Caixia

The processes of lactic acid production include two key stages, which are (a) fermentation and (b) product recovery. In this study, free cell of Bifidobacterium longum was used to produce lactic acid from cheese whey. The produced lactic acid was then separated and purified from the fermentation broth using combination of nanofiltration and reverse osmosis membranes. Nanofiltration membrane with a molecular weight cutoff of 100-400 Da was used to separate lactic acid from lactose and cells in the cheese whey fermentation broth in the first step. The obtained permeate from the above nanofiltration is mainly composed of lactic acid and water, which was then concentrated with a reverse osmosis membrane in the second step. Among the tested nanofiltration membranes, HL membrane from GE Osmonics has the highest lactose retention (97±1%). In the reverse osmosis process, the ADF membrane could retain 100% of lactic acid to obtain permeate with water only. The effect of membrane and pressure on permeate flux and retention of lactose/lactic acid was also reported in this paper.

Recovering/concentrating of hemicellulosic sugars and acetic acid by nanofiltration and reverse osmosis from prehydrolysis liquor of kraft based hardwood dissolving pulp process.

PubMed

Ahsan, Laboni; Jahan, M Sarwar; Ni, Yonghao

2014-03-01

This work investigated the feasibility of recovering and concentrating sugars and acetic acid (HAc) from prehydrolysis liquor (PHL) of the kraft-based dissolving pulp process prior to fermentation of hemicellulosic sugars, by the combination of activated carbon adsorption, nanofiltration (NF) and reverse osmosis (RO) processes. To reduce the fouling PHL was subjected to adsorption on activated carbon, then the treated PHL (TPHL) passed through a nanofiltration (NF DK) membrane to retain the sugars, and the permeate of acetic acid rich solution was passed through a reverse osmosis membrane (RO SG). It was found that for NF process sugars were concentrated from 48 to 227g/L at a volume reduction factor (VRF) of 5 while 80 to 90% of acetic acid was permeated. For the reverse osmosis process, 68% of acetic acid retention was achieved at pH 4.3 and 500 psi pressure and the HAc concentration increased from 10 to 50g/L. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Advanced Control Synthesis for Reverse Osmosis Water Desalination Processes.

PubMed

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.

Evaluation of Treatment Technologies for Wastewater from Insensitive Munitions Production. Phase 1: Technology Down-Selection

DTIC Science & Technology

2013-11-01

the AOP reactor according to the target process formulation. Gases were vented to a GAC vessel. ERDC/EL TR-13-20 94 10.2.2 Results and Discussion...destructive and filtration methods such as biological treatment (destructive), chemical reduction (destructive), reverse osmosis (RO)/nano- filtration ... filtration ), and advanced oxidation processes (destructive). A comprehensive evaluation of alternatives relies on a detailed list of criteria, allowing for

Membrane-Based Technologies in the Pharmaceutical Industry and Continuous Production of Polymer-Coated Crystals/Particles.

PubMed

Chen, Dengyue; Sirkar, Kamalesh K; Jin, Chi; Singh, Dhananjay; Pfeffer, Robert

2017-01-01

Membrane technologies are of increasing importance in a variety of separation and purification applications involving liquid phases and gaseous mixtures. Although the most widely used applications at this time are in water treatment including desalination, there are many applications in chemical, food, healthcare, paper and petrochemical industries. This brief review is concerned with existing and emerging applications of various membrane technologies in the pharmaceutical and biopharmaceutical industry. The goal of this review article is to identify important membrane processes and techniques which are being used or proposed to be used in the pharmaceutical and biopharmaceutical operations. How novel membrane processes can be useful for delivery of crystalline/particulate drugs is also of interest. Membrane separation technologies are extensively used in downstream processes for bio-pharmaceutical separation and purification operations via microfiltration, ultrafiltration and diafiltration. Also the new technique of membrane chromatography allows efficient purification of monoclonal antibodies. Membrane filtration techniques of reverse osmosis and nanofiltration are being combined with bioreactors and advanced oxidation processes to treat wastewaters from pharmaceutical plants. Nanofiltration with organic solvent-stable membranes can implement solvent exchange and catalyst recovery during organic solvent-based drug synthesis of pharmaceutical compounds/intermediates. Membranes in the form of hollow fibers can be conveniently used to implement crystallization of pharmaceutical compounds. The novel crystallization methods of solid hollow fiber cooling crystallizer (SHFCC) and porous hollow fiber anti-solvent crystallization (PHFAC) are being developed to provide efficient methods for continuous production of polymer-coated drug crystals in the area of drug delivery. This brief review provides a general introduction to various applications of membrane technologies in the pharmaceutical/biopharmaceutical industry with special emphasis on novel membrane techniques for pharmaceutical applications. The method of coating a drug particle with a polymer using the SHFCC method is stable and ready for scale-up for operation over an extended period. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shamsuddin Ilias

Fouling problems are perhaps the single most important reason for relatively slow acceptance of ultrafiltration in many areas of chemical and biological processing. To overcome the losses in permeate flux associated with concentration polarization and fouling in cross flow membrane filtration, we investigated the concept of flow reversal as a method to enhance membrane flux in ultrafiltration. Conceptually, flow reversal prevents the formation of stable hydrodynamic and concentration boundary layers at or near the membrane surface. Further more, periodic reversal of the flow direction of the feed stream at the membrane surface results in prevention and mitigation of membrane fouling.more » Consequently, these advantages are expected to enhance membrane flux significantly. A crossflow membrane filtration unit was designed and built to test the concept of periodic flow reversal for flux enhancement. The essential elements of the system include a crossflow hollow fiber membrane module integrated with a two-way valve to direct the feed flow directions. The two-way valve is controlled by a controller-timer for periodic reversal of flow of feed stream. Another important feature of the system is that with changing feed flow direction, the permeate flow direction is also changed to maintain countercurrent feed and permeate flows for enhanced mass transfer driving force (concentration difference). Three feed solutions (Bovine serum albumin (BSA), apple juice and citrus fruit pectin) were studied in crossflow membrane filtration. These solutes are well-known in membrane filtration for their fouling and concentration polarization potentials. Laboratory-scale tests on a hollow-fiber ultrafiltration membrane module using each of the feed solutes show that under flow reversal conditions, the permeate flux is significantly enhanced when compared with the conventional unidirectional flow. The flux enhancement is dramatic (by an order of magnitude) with increased feed concentration and operating transmembrane pressure. Thus, flow reversal technology seems an attractive alternative to mitigate fouling problem in crossflow membrane filtration.« less

The Development of a Test System for the Evaluation of Reverse Osmosis Water Purification Membranes

DTIC Science & Technology

1984-06-01

processes consist of high rate filtration followed by the reverse osmosis system. Under the present concept there will be two units: one will produce 600...of the National Toxicology Program, National Institute of Health. No official data has. been released on the teratogenicity of D.MMP. Healh ýz

27 CFR 24.248 - Processes authorized for the treatment of wine, juice, and distilling material.

Code of Federal Regulations, 2012 CFR

2012-04-01

....2910. 1 This process must be done on distilled spirits plant premises. However, reverse osmosis, under... vinous character of the wine (2) None of the stripping solution may migrate into the wine. Reverse osmosis 1 To reduce the ethyl alcohol content of wine and to remove off flavors in wine Permeable...

27 CFR 24.248 - Processes authorized for the treatment of wine, juice, and distilling material.

Code of Federal Regulations, 2013 CFR

2013-04-01

....2910. 1 This process must be done on distilled spirits plant premises. However, reverse osmosis, under... vinous character of the wine (2) None of the stripping solution may migrate into the wine. Reverse osmosis 1 To reduce the ethyl alcohol content of wine and to remove off flavors in wine Permeable...

EFFECTS OF REVERSE OSMOSIS ISOLATION ON REACTIVITY OF NATURALLY OCCURRING DISSOLVED ORGANIC MATTER IN PHYSICOCHEMICAL PROCESSES. (R828045)

EPA Science Inventory

A field reverse osmosis system was used to isolate dissolved organic matter (DOM) from two lacustrine and two riverine surface water sources. The rejection of DOM was on the order of 99% and did not vary significantly with pressure. A simple mass balance model using a single m...

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

ERIC Educational Resources Information Center

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…

Integration of biological method and membrane technology in treating palm oil mill effluent.

PubMed

Zhang, Yejian; Yan, Li; Qiao, Xiangli; Chi, Lina; Niu, Xiangjun; Mei, Zhijian; Zhang, Zhenjia

2008-01-01

Palm oil industry is the most important agro-industry in Malaysia, but its by-product-palm oil mill effluent (POME), posed a great threat to water environment. In the past decades, several treatment and disposal methods have been proposed and investigated to solve this problem. A two-stage pilot-scale plant was designed and constructed for POME treatment. Anaerobic digestion and aerobic biodegradation constituted the first biological stage, while ultrafiltration (UF) and reverse osmosis (RO) membrane units were combined as the second membrane separation stage. In the anaerobic expanded granular sludge bed (EGSB) reactor, about 43% organic matter in POME was converted into biogas, and COD reduction efficiency reached 93% and 22% in EGSB and the following aerobic reactor, respectively. With the treatment in the first biological stage, suspended solids and oil also decreased to a low degree. All these alleviated the membrane fouling and prolonged the membrane life. In the membrane process unit, almost all the suspended solids were captured by UF membranes, while RO membrane excluded most of the dissolved solids or inorganic salts from RO permeate. After the whole treatment processes, organic matter in POME expressed by BOD and COD was removed almost thoroughly. Suspended solids and color were not detectable in RO permeate any more, and mineral elements only existed in trace amount (except for K and Na). The high-quality effluent was crystal clear and could be used as the boiler feed water.

Effect of dairy powders fortification on yogurt textural and sensorial properties: a review.

PubMed

Karam, Marie Celeste; Gaiani, Claire; Hosri, Chadi; Burgain, Jennifer; Scher, Joël

2013-11-01

Yogurts are important dairy products that have known a rapid market growth over the past few decades. Industrial yogurt manufacture involves different processing steps. Among them, protein fortification of the milk base is elemental. It greatly enhances yogurt nutritional and functional properties and prevents syneresis, an undesirable yogurt textural defect. Protein enrichment can be achieved by either concentration process (evaporation under vacuum and membrane processing: reverse osmosis and/or ultrafiltration) or by addition of dairy ingredients. Traditionally, skim milk powder (SMP) is used to enrich the milk base before fermentation. However, increased quality and availability of other dairy ingredients such as milk protein isolates (MPI), milk protein concentrates (MPC) whey protein isolates (WPI) and concentrates (WPC), micellar casein (MC) and caseinates have promoted their use as alternatives to SMP. Substituting different dry ingredients for skim milk powder in yogurt making affects the yogurt mix protein composition and subsequent textural and sensorial properties. This review focuses on various type of milk protein used for fortification purposes and their influence on these properties.

RECOVERY OF MUTAGENICITY FROM DISINFECTED WATER BY XAD RESIN ADSORPTION COMPARED TO REVERSE OSMOSIS

EPA Science Inventory

Recovery of Mutagenicity from Disinfected Water Samples by XAD Resin Adsorption Compared to Reverse Osmosis

K. M. Schenck1, T. F. Speth1, R. J. Miltner1, M. Sivaganesan1 and J. E. Simmons2

1U.S. EPA, Office of Research and Development, NRMRL
2U.S. EPA, Office of...

A centrifugal method for the evaluation of polymer membranes for reverse osmosis

NASA Technical Reports Server (NTRS)

Hollahan, J. R.; Wydeven, T.; Mccullough, R. P.

1973-01-01

A rapid and simple method employing the laboratory centrifuge shows promise for evaluation of membrane performance during reverse osmosis. Results are presented for cellulose acetate membranes for rejection of salt and urea dissolved solids. Implications of the study are to rapid screening of membrane performance, use in laboratories with limited facilities, and possible space waste water purification.

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

ERIC Educational Resources Information Center

Lehtihalmes, Matti; And Others

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

Spray drying of a phenolic-rich membrane filtration fraction of olive mill wastewater: Optimization and dried product quality

USDA-ARS?s Scientific Manuscript database

Olive mill wastewater (OMWW) from two California mills (3-phase and 2-phase) was subjected to a two-step membrane filtration process using a novel vibratory system. The obtained reverse osmosis retentate (RO-R) is a phenolic-rich co-product stream, and the reverse osmosis permeate is a near-pure wat...

ARSENIC REMOVAL FROM DRINKING WATER BY POINT OF USE REVERSE OSMOSIS. EPA DEMONSTRATION PROJECT AT SUNSET RANCH DEVELOPMENT IN HOMEDALE, ID. SIX-MONTH EVALUATION REPORT

EPA Science Inventory

This report documents the activities performed during and the results obtained from the first six months of the point of use arsenic removal treatment technology demonstration project at the Sunset Ranch Development in Homedale, ID. The objectives of the project are to evaluate t...

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - PHYSICAL REMOVAL OF MICROBIAL CONTAMINATION AGENTS IN DRINKING WATER, WATTS P{REMIER ULTRA 5 REVERSE OSMOSIS DRINKING WATER TREATMENT SYSTEM (POU)

EPA Science Inventory

The Watts Premier Ultra 5 system was tested for removal of bacteria and viruses at NSF International's Laboratory. Watts Premier submitted ten units, which were split into two groups of five. One group received 25 days of conditioning prior to challenge testing, while the secon...

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

EPA Science Inventory

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

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

PubMed

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.

Technoeconomic Optimization of Waste Heat Driven Forward Osmosis for Flue Gas Desulfurization Wastewater Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gingerich, Daniel B; Bartholomew, Timothy V; Mauter, Meagan S

With the Environmental Protection Agency’s recent Effluent Limitation Guidelines for Steam Electric Generators, power plants are having to install and operate new wastewater technologies. Many plants are evaluating desalination technologies as possible compliance options. However, the desalination technologies under review that can reduce wastewater volume or treat to a zero-liquid discharges standard have a significant energy penalty to the plant. Waste heat, available from the exhaust gas or cooling water from coal-fired power plants, offers an opportunity to drive wastewater treatment using thermal desalination technologies. One such technology is forward osmosis (FO). Forward osmosis utilizes an osmotic pressure gradient tomore » passively pull water from a saline or wastewater stream across a semi-permeable membrane and into a more concentrated draw solution. This diluted draw solution is then fed into a distillation column, where the addition of low temperature waste heat can drive the separation to produce a reconcentrated draw solution and treated water for internal plant reuse. The use of low-temperature waste heat decouples water treatment from electricity production and eliminates the link between reducing water pollution and increasing air emissions from auxiliary electricity generation. In order to evaluate the feasibility of waste heat driven FO, we first build a model of an FO system for flue gas desulfurization (FGD) wastewater treatment at coal-fired power plants. This model includes the FO membrane module, the distillation column for draw solution recovery, and waste heat recovery from the exhaust gas. We then add a costing model to account for capital and operating costs of the forward osmosis system. We use this techno-economic model to optimize waste heat driven FO for the treatment of FGD wastewater. We apply this model to three case studies: the National Energy Technology Laboratory (NETL) 550 MW model coal fired power plant without carbon capture and sequestration, the NETL 550 MW model coal fired power plant with carbon capture and sequestration, and Plant Bowen in Eularhee, Georgia. For each case, we identify the design that minimizes the cost of wastewater treatment given the safely recoverable waste heat. We benchmark the cost minimum waste-heat forward osmosis solutions to two conventional options that rely on electricity, reverse osmosis and mechanical vapor recompression. Furthermore, we quantify the environmental damages from the emissions of carbon dioxide and criteria air pollutants for each treatment option. With this information we can assess the trade-offs between treatment costs, energy consumption, and air emissions between the treatment options.« less

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

PubMed Central

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

2011-01-01

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

CHEMICAL ANALYSIS OF REVERSE OSMOSIS MEMBRANE AND XAD RESIN ADSORPTION CONCENTRATES OF WATER DISINFECTED BY CHLORINATION OR OZONATION/CHLORINATION PROCESSES

EPA Science Inventory

Chemical Analysis of Reverse Osmosis Membrane and XAD Resin Adsorption Concentrates of Water Disinfected by Chlorination or Ozonation/Chlorination Processes.

J. E. Simmons1, S.D. Richardson2, K.M. Schenck3, T. F. Speth3, R. J. Miltner3 and A. D. Thruston2

1 NHEE...

Membrane Technologies in Wine Industry: An Overview.

PubMed

El Rayess, Youssef; Mietton-Peuchot, Martine

2016-09-09

Membrane processes are increasingly reported for various applications in wine industry such as microfiltration, electrodialysis, and reverse osmosis, but also emerging processes as bipolar electrodialysis and membrane contactor. Membrane-based processes are playing a critical role in the field of separation/purification, clarification, stabilization, concentration, and de-alcoholization of wine products. They begin to be an integral part of the winemaking process. This review will provide an overview of recent developments, applications, and published literature in membrane technologies applied in wine industry.

A Biologically-Based Alternative Water Processor for Long Duration Space Missions

NASA Technical Reports Server (NTRS)

Barta, Daniel J.; Pickering, Karen D.; Meyer, Caitlin; Pensinger, Stuart; Vega, Leticia; Flynn, Michael; Jackson, Andrew; Wheeler, Raymond

2015-01-01

A wastewater recovery system has been developed that combines novel biological and physicochemical components for recycling wastewater on long duration space missions. Functionally, this Alternative Water Processor (AWP) would replace the Urine Processing Assembly on the International Space Station and reduce or eliminate the need for the multifiltration beds of the Water Processing Assembly (WPA). At its center are two unique game changing technologies: 1) a biological water processor (BWP) to mineralize organic forms of carbon and nitrogen and 2) an advanced membrane processor (Forward Osmosis Secondary Treatment) for removal of solids and inorganic ions. The AWP is designed for recycling larger quantities of wastewater from multiple sources expected during future exploration missions, including urine, hygiene (hand wash, shower, oral and shave) and laundry. The BWP utilizes a single-stage membrane-aerated biological reactor for simultaneous nitrification and denitrification. The Forward Osmosis Secondary Treatment (FOST) system uses a combination of forward osmosis (FO) and reverse osmosis (RO), is resistant to biofouling and can easily tolerate wastewaters high in non-volatile organics and solids associated with shower and/or hand washing. The BWP was operated continuously for over 300 days. After startup, the mature biological system averaged 85% organic carbon removal and 44% nitrogen removal, close to maximum based on available carbon. The FOST has averaged 93% water recovery, with a maximum of 98%. If the wastewater is slighty acidified, ammonia rejection is optimal. This paper will provide a description of the technology and summarize results from ground-based testing using real wastewater.

Methodological approaches to conducting pilot and proof tests on reverse-osmosis systems: Results of comparative studies

NASA Astrophysics Data System (ADS)

Panteleev, A. A.; Bobinkin, V. V.; Larionov, S. Yu.; Ryabchikov, B. E.; Smirnov, V. B.; Shapovalov, D. A.

2017-10-01

When designing large-scale water-treatment plants based on reverse-osmosis systems, it is proposed to conduct experimental-industrial or pilot tests for validated simulation of the operation of the equipment. It is shown that such tests allow establishing efficient operating conditions and characteristics of the plant under design. It is proposed to conduct pilot tests of the reverse-osmosis systems on pilot membrane plants (PMPs) and test membrane plants (TMPs). The results of a comparative experimental study of pilot and test membrane plants are exemplified by simulating the operating parameters of the membrane elements of an industrial plant. It is concluded that the reliability of the data obtained on the TMP may not be sufficient to design industrial water-treatment plants, while the PMPs are capable of providing reliable data that can be used for full-scale simulation of the operation of industrial reverse-osmosis systems. The test membrane plants allow simulation of the operating conditions of individual industrial plant systems; therefore, potential areas of their application are shown. A method for numerical calculation and experimental determination of the true selectivity and the salt passage are proposed. An expression has been derived that describes the functional dependence between the observed and true salt passage. The results of the experiments conducted on a test membrane plant to determine the true value of the salt passage of a reverse-osmosis membrane are exemplified by magnesium sulfate solution at different initial operating parameters. It is shown that the initial content of a particular solution component has a significant effect on the change in the true salt passage of the membrane.

ARSENIC REMOVAL FROM DRINKING WATER BY POINT-OF-USE (POU) REVERSE OSMOSIS. U.S. EPA DEMONSTRATION PROJECT AT SUNSET RANCH DEVELOPMENT IN HOMEDALE, ID. FINAL PERFORMANCE EVALUATION REPORT

EPA Science Inventory

This report documents the activities performed during and the results obtained from the arsenic removal technology demonstration project at the Sunset Ranch Development in Homedale, ID. The objectives of the project are to evaluate: 1) the effectiveness of a point of use (POU) re...

Innovative Treatment Technologies for Natural Waters and Wastewaters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Childress, Amy E.

2011-07-01

The research described in this report focused on the development of novel membrane contactor processes (in particular, forward osmosis (FO), pressure retarded osmosis (PRO), and membrane distillation (MD)) in low energy desalination and wastewater treatment applications and in renewable energy generation. FO and MD are recently gaining national and international attention as viable, economic alternatives for removal of both established and emerging contaminants from natural and process waters; PRO is gaining worldwide attention as a viable source of renewable energy. The interrelationship of energy and water are at the core of this study. Energy and water are inextricably bound; energymore » usage and production must be considered when evaluating any water treatment process for practical application. Both FO and MD offer the potential for substantial energy and resource savings over conventional treatment processes and PRO offers the potential for renewable energy or energy offsets in desalination. Combination of these novel technologies with each other, with existing technologies (e.g., reverse osmosis (RO)), and with existing renewable energy sources (e.g., salinity gradient solar ponds) may enable much less expensive water production and also potable water production in remote or distributed locations. Two inter-related projects were carried out in this investigation. One focused on membrane bioreactors for wastewater treatment and PRO for renewable energy generation; the other focused on MD driven by a salinity gradient solar pond.« less

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

PubMed

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

2012-02-01

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

Forward Osmosis in Wastewater Treatment Processes.

PubMed

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.

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

PubMed Central

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

2016-01-01

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

Automated Water-Purification System

NASA Technical Reports Server (NTRS)

Ahlstrom, Harlow G.; Hames, Peter S.; Menninger, Fredrick J.

1988-01-01

Reverse-osmosis system operates and maintains itself with minimal human attention, using programmable controller. In purifier, membranes surround hollow cores through which clean product water flows out of reverse-osmosis unit. No chemical reactions or phase changes involved. Reject water, in which dissolved solids concentrated, emerges from outer membrane material on same side water entered. Flow controls maintain ratio of 50 percent product water and 50 percent reject water. Membranes expected to last from 3 to 15 years.

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

NASA Technical Reports Server (NTRS)

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

1980-01-01

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

Modeling of membrane processes for air revitalization and water recovery

NASA Technical Reports Server (NTRS)

Lange, Kevin E.; Foerg, Sandra L.; Dall-Bauman, Liese A.

1992-01-01

Gas-separation and reverse-osmosis membrane models are being developed in conjunction with membrane testing at NASA JSC. The completed gas-separation membrane model extracts effective component permeabilities from multicomponent test data, and predicts the effects of flow configuration, operating conditions, and membrane dimensions on module performance. Variable feed- and permeate-side pressures are considered. The model has been applied to test data for hollow-fiber membrane modules with simulated cabin-air feeds. Results are presented for a membrane designed for air drying applications. Extracted permeabilities are used to predict the effect of operating conditions on water enrichment in the permeate. A first-order reverse-osmosis model has been applied to test data for spiral wound membrane modules with a simulated hygiene water feed. The model estimates an effective local component rejection coefficient under pseudosteady-state conditions. Results are used to define requirements for a detailed reverse-osmosis model.

Relating Silica Scaling in Reverse Osmosis to Membrane Surface Properties.

PubMed

Tong, Tiezheng; Zhao, Song; Boo, Chanhee; Hashmi, Sara M; Elimelech, Menachem

2017-04-18

We investigated the relationship between membrane surface properties and silica scaling in reverse osmosis (RO). The effects of membrane hydrophilicity, free energy for heterogeneous nucleation, and surface charge on silica scaling were examined by comparing thin-film composite polyamide membranes grafted with a variety of polymers. Results show that the rate of silica scaling was independent of both membrane hydrophilicity and free energy for heterogeneous nucleation. In contrast, membrane surface charge demonstrated a strong correlation with the extent of silica scaling (R 2 > 0.95, p < 0.001). Positively charged membranes significantly facilitated silica scaling, whereas a more negative membrane surface charge led to reduced scaling. This observation suggests that deposition of negatively charged silica species on the membrane surface plays a critical role in silica scale formation. Our findings provide fundamental insights into the mechanisms governing silica scaling in reverse osmosis and highlight the potential of membrane surface modification as a strategy to reduce silica scaling.

Biofouling in reverse osmosis: phenomena, monitoring, controlling and remediation

NASA Astrophysics Data System (ADS)

Maddah, Hisham; Chogle, Aman

2017-10-01

This paper is a comprehensive review of biofouling in reverse osmosis modules where we have discussed the mechanism of biofouling. Water crisis is an issue of pandemic concern because of the steady rise in demand of drinking water. Overcoming biofouling is vital since we need to optimize expenses and quality of potable water production. Various kinds of microorganisms responsible for biofouling have been identified to develop better understanding of their attacking behavior enabling us to encounter the problem. Both primitive and advanced detection techniques have been studied for the monitoring of biofilm development on reverse osmosis membranes. Biofouling has a negative impact on membrane life as well as permeate flux and quality. Thus, a mathematical model has been presented for the calculation of normalized permeate flux for evaluating the extent of biofouling. It is concluded that biofouling can be controlled by the application of several physical and chemical remediation techniques.

Market Analysis and Material Evaluation of Coagulants for Reverse Osmosis Water Purification Units

DTIC Science & Technology

1990-09-28

three identified primary coagulants. Electrocoagulation , an emerging technology, was also discovered as being a relatively new area of research with great...there is yet another avenue the Army needs to explore -- electrocoagulation . 4.3.2 Electrocoagulation | * Electrocoagulation processes utilize an...7). A typical electrocoagulator consists of a combination of a treating chamber, which operates as an electrolytic cell, with a water-inlet and a

Treatment of chromium contaminated plating shop rinsewater streams by reverse osmosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walker, J.F.; Brown, C.H. Jr.; Wilson, J.H.

1988-01-01

Wastewater is discharged to the local sanitary sewer, which is regulated by a Metropolitan Sewer District (MSD). The MSD has established discharge limits and reports have indicated that the major source of wastewater and primary area of concern is the discharge from the industrial plating shop within the plant complex. This plating shop generates /approximately/1100 m/sup 3/ (300,000 gal) of wastewater per day. Because construction of a new plating shop is currently planned, a complete renovation of the existing plating shop is not economically feasible. The sponsor demonstrated the use of innovative wastewater treatment technologies that will minimize the amountmore » of wastewater generated from the plating processes and maintain compliance with MSD discharge limits until the new plating shop is constructed. The problems at the facility have been analyzed and a treatment system utilizing reverse osmosis (RO), with volume reduction of the RO concentrate by evaporation, has been recommended. The utilization of RO meets the specification for the demonstration of innovative technology. This paper discusses the problem analysis at the plant as well as the results of a pilot scale RO test program currently being conducted. The installation of the full scale unit is dependent on the successful completion of the RO pilot tests. 1 ref., 6 figs., 3 tabs.« less

Reinvigorating Reverse-Osmosis Membrane Technology to Stabilize the V 2 O 5 Lithium-Ion Battery Cathode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Ji; Byrd, Ian; Jin, Congrui

V 2O 5 is deemed as one of the most promising cathode materials for next-generation high-capacity lithium-ion batteries (LIBs). It possesses a theoretical capacity of 294 mAh g -1, which is much higher than conventional cathodes. But, there are many issues to be solved before its practical use, including poor cycle life and unsatisfactory rate performance, mainly owing to its low electronic conductivity and ionic diffusivity, as well as structural instability. Our work reports three types of V 2O 5 asymmetric membranes synthesized by using an adapted reverse-osmosis membrane technology combined with sol-gel chemistry, aiming to stabilize the cyclability andmore » improve the rate performance. V 2O 5 asymmetric membrane cathodes prepared using graphene as the conductive additives have a specific capacity of approximately 160 mAh g -1 at a current density of 100 mA g -1 with no capacity degradation after 380 cycles. It is also found that the annealing temperature and the choice of conductive additives can affect the morphology of V 2O 5 nanoparticles and the overall electrode cyclability. Furthermore, we find that a lower annealing temperature (300 vs. 400 °C) and the addition of graphene are beneficial to long-term cycling performance.« less

Reinvigorating Reverse-Osmosis Membrane Technology to Stabilize the V 2 O 5 Lithium-Ion Battery Cathode

DOE PAGES

Wu, Ji; Byrd, Ian; Jin, Congrui; ...

2017-02-27

V 2O 5 is deemed as one of the most promising cathode materials for next-generation high-capacity lithium-ion batteries (LIBs). It possesses a theoretical capacity of 294 mAh g -1, which is much higher than conventional cathodes. But, there are many issues to be solved before its practical use, including poor cycle life and unsatisfactory rate performance, mainly owing to its low electronic conductivity and ionic diffusivity, as well as structural instability. Our work reports three types of V 2O 5 asymmetric membranes synthesized by using an adapted reverse-osmosis membrane technology combined with sol-gel chemistry, aiming to stabilize the cyclability andmore » improve the rate performance. V 2O 5 asymmetric membrane cathodes prepared using graphene as the conductive additives have a specific capacity of approximately 160 mAh g -1 at a current density of 100 mA g -1 with no capacity degradation after 380 cycles. It is also found that the annealing temperature and the choice of conductive additives can affect the morphology of V 2O 5 nanoparticles and the overall electrode cyclability. Furthermore, we find that a lower annealing temperature (300 vs. 400 °C) and the addition of graphene are beneficial to long-term cycling performance.« less

Preparation and Characterization of Thin-Film Composite Membrane with Nanowire-Modified Support for Forward Osmosis Process

PubMed Central

Low, Ze-Xian; Liu, Qi; Shamsaei, Ezzatollah; Zhang, Xiwang; Wang, Huanting

2015-01-01

Internal concentration polarization (ICP) in forward osmosis (FO) process is a characteristic problem for asymmetric thin-film composite (TFC) FO membrane which leads to lower water flux. To mitigate the ICP effect, modification of the substrates’ properties has been one of the most effective methods. A new polyethersulfone-based ultrafiltration membrane with increased surface porosity and high water flux was recently produced by incorporating Zn2GeO4 nanowires. The composite membrane was used as a substrate for the fabrication of TFC FO membrane, by coating a thin layer of polyamide on top of the substrate. The substrate and the nanowires were characterized by a range of techniques such as SEM, XRD, and contact angle goniometry. The water permeability and molecular weight cut-offs (MWCO) of the substrate; and the FO performance of the TFC membrane were also determined. The Zn2GeO4-modified membrane showed ~45% increase in water permeability and NaCl salt rejection of 80% under RO mode. In FO mode, the ratio of water flux to reverse solute flux was also improved. However, lower FO flux was obtained which could be due to ICP. The result shows that Zn2GO4 nanowire may be used as a modifier to the substrate to improve the quality of the polyamide layer on the substrate to improve the flux and selectivity, but not as effective in reducing ICP. This work demonstrates that the incorporation of nanomaterials to the membrane substrate may be an alternative approach to improve the formation of polyamide skin layer to achieve better FO performance. PMID:25803239

An Alternative Water Processor for Long Duration Space Missions

NASA Technical Reports Server (NTRS)

Barta, Daniel J.; Pickering, Karen D.; Meyer, Caitlin; Pennsinger, Stuart; Vega, Leticia; Flynn, Michael; Jackson, Andrew; Wheeler, Raymond

2014-01-01

A new wastewater recovery system has been developed that combines novel biological and physicochemical components for recycling wastewater on long duration human space missions. Functionally, this Alternative Water Processor (AWP) would replace the Urine Processing Assembly on the International Space Station and reduce or eliminate the need for the multi-filtration beds of the Water Processing Assembly (WPA). At its center are two unique game changing technologies: 1) a biological water processor (BWP) to mineralize organic forms of carbon and nitrogen and 2) an advanced membrane processor (Forward Osmosis Secondary Treatment) for removal of solids and inorganic ions. The AWP is designed for recycling larger quantities of wastewater from multiple sources expected during future exploration missions, including urine, hygiene (hand wash, shower, oral and shave) and laundry. The BWP utilizes a single-stage membrane-aerated biological reactor for simultaneous nitrification and denitrification. The Forward Osmosis Secondary Treatment (FOST) system uses a combination of forward osmosis (FO) and reverse osmosis (RO), is resistant to biofouling and can easily tolerate wastewaters high in non-volatile organics and solids associated with shower and/or hand washing. The BWP has been operated continuously for over 300 days. After startup, the mature biological system averaged 85% organic carbon removal and 44% nitrogen removal, close to stoichiometric maximum based on available carbon. To date, the FOST has averaged 93% water recovery, with a maximum of 98%. If the wastewater is slighty acidified, ammonia rejection is optimal. This paper will provide a description of the technology and summarize results from ground-based testing using real wastewater

Flux Recovery of a Forward Osmosis Membrane After a Fouling Process

NASA Technical Reports Server (NTRS)

Gamboa-Vázquez, Sonia; Flynn, Michael; Romero Mangado, Jaione; Parodi, Jurek

2016-01-01

Wastewater treatment through Forward Osmosis (FO) membranes is a process that has been evaluated in the past years as an innovative technology for the Next Generation Life Support Systems. FO technologies are cost effective, and require very low energy consumption, but are subject to membrane fouling. Membrane fouling occurs when unwanted materials accumulate on the active side of the membrane during the wastewater treatment process, which leads to a decrease in membrane flow rates. Membrane fouling can be reversed with the use of antifoulant solutions. The aim of this study is to identify the materials that cause flow rate reduction due to membrane fouling, as well as to evaluate the flux recovery after membrane treatment using commercially available antifoulants. 3D Laser Scanning Microscope images were taken to observe the surface of the membrane. Fourier Transform Infrared (FTIR) spectrometry results identified possible compounds that cause membrane fouling and FO testing results demonstrated flow rate recovery after membrane treatment using antifoulants.

Modeling pH variation in reverse osmosis.

PubMed

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.

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

PubMed

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

2014-12-01

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

Nanotechnology for sustainable wastewater treatment and use for agricultural production: A comparative long-term study.

PubMed

De La Cueva Bueno, Patricia; Gillerman, Leonid; Gehr, Ronald; Oron, Gideon

2017-03-01

Nanotechnology applications can be used for filtering low quality waters, allowing under given conditions, the removal of salts and other micropollutants from these waters. A long-term field experiment, implementing nanotechnology in the form of UltraFiltration (UF) and Reverse Osmosis (RO) for salt removal from treated wastewater, was conducted with secondary effluents, aiming to prove the sustainability of agricultural production using irrigation with treated wastewater. Six outdoor field treatments, each under four replications, were conducted for examining the salt accumulation effects on the soil and the crops. The field experiments proved that crop development is correlated with the water quality as achieved from the wastewater filtration capability of the hybrid nanotechnology system. The key goal was to maintain sustainable food production, despite the low quality of the waters. Of the six treatment methods tested, irrigation with RO-treated effluent produced the best results in terms of its effect on soil salinity and crop yield. Nevertheless, it must be kept in mind that this process is not only costly, but it also removes all organic matter content from the irrigation water, requiring the addition of fertilizers to the effluent. Copyright © 2016. Published by Elsevier Ltd.

Seasonal Variation of Infiltration Rates in a Managed Aquifer Recharge System: A Belgian Example

NASA Astrophysics Data System (ADS)

Samanta, S.; Sheng, Z.; Munster, C. L.; Houtte, E. V.

2017-12-01

Managed Aquifer Recharge (MAR) is a powerful tool in addressing water resources management issues. The Torreele water reuse facility is using MAR to address the problem of water sustainability in a coastal aquifer of Belgium. The Torreele MAR facility uses infiltration ponds to maintain the groundwater level and to prevent saltwater intrusion into the aquifer. The source of recharge is treated wastewater from the Torreele wastewater treatment plant (TWWTP) located 1.2 km inland. The TWWTP uses a state-of-the-art filtration mechanism with a combination of ultrafiltration (UF) and Reverse Osmosis (RO) techniques to assure that recharge water is of very high quality. Data collected at the Torreele MAR facility indicates reduced infiltration rates during the winter season when pond water temperatures vary from 1 to 10ºC. The proposed hypothesis for these lower infiltration rates may be a reduction in hydraulic conductivity due to changes in water viscosity. This study involves the determination of relationship between water temperature, infiltration rates, and hydraulic conductivity at the Torreele MAR facility. The results of this study will lead to an effective administration of the facility and provide an extensive understanding of the system.

Monitoring the occurrence of emerging contaminants in treated wastewater and groundwater between 2008 and 2010. The Baix Llobregat (Barcelona, Spain).

PubMed

Cabeza, Y; Candela, L; Ronen, D; Teijon, G

2012-11-15

The occurrence of 166 emerging compounds and four heavy metals (Cd, Ni, Hg and Pb) in treated wastewater and groundwater has been monitored at the Llobregat delta (Barcelona, Spain) over a period of 3 years. Selected compounds were pharmaceuticals, personal care products (PCPs), dioxins, polycyclic aromatic hydrocarbons (PAHs) and priority substances included in the 2008/105/CE Directive. Analysis was performed in tertiary treated wastewater (TWW), after an additional treatment of ultrafiltration reverse osmosis and UV disinfection, and groundwater from a deep confined aquifer. This aquifer is artificially recharged with TWW through injection wells. After the advanced treatment, 38 pharmaceuticals, 9 PCPs, 9 pesticides and 7 PAHs still showed a frequency of detection higher than 25% in the TWW, although at low concentration levels (ng/l). Not all active compounds found in the TWW were present in groundwater, indicating possible degradation within the aquifer media after the injection. A number of chemicals, mainly 10 pesticides and 10 pharmaceuticals were only present in groundwater samples, confirming a different origin than the injected TWW, probably agricultural activities and/or infiltration of poorly treated wastewater. Copyright © 2012 Elsevier B.V. All rights reserved.

Biological control of biofilms on membranes by metazoans.

PubMed

Klein, Theresa; Zihlmann, David; Derlon, Nicolas; Isaacson, Carl; Szivak, Ilona; Weissbrodt, David G; Pronk, Wouter

2016-01-01

Traditionally, chemical and physical methods have been used to control biofouling on membranes by inactivating and removing the biofouling layer. Alternatively, the permeability can be increased using biological methods while accepting the presence of the biofouling layer. We have investigated two different types of metazoans for this purpose, the oligochaete Aelosoma hemprichi and the nematode Plectus aquatilis. The addition of these grazing metazoans in biofilm-controlled membrane systems resulted in a flux increase of 50% in presence of the oligochaetes (Aelosoma hemprichi), and a flux increase of 119-164% in presence of the nematodes (Plectus aquatilis) in comparison to the control system operated without metazoans. The change in flux resulted from (1) a change in the biofilm structure, from a homogeneous, cake-like biofilm to a more heterogeneous, porous structure and (2) a significant reduction in the thickness of the basal layer. Pyrosequencing data showed that due to the addition of the predators, also the community composition of the biofilm in terms of protists and bacteria was strongly affected. The results have implications for a range of membrane processes, including ultrafiltration for potable water production, membrane bioreactors and reverse osmosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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.

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

PubMed Central

Bejaoui, Imen; Mouelhi, Meral; Hamrouni, Béchir

2017-01-01

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. PMID:28819360

Reverse osmosis filtration for space mission wastewater: membrane properties and operating conditions

NASA Technical Reports Server (NTRS)

Lee, S.; Lueptow, R. M.

2001-01-01

Reverse osmosis (RO) is a compact process that has potential for the removal of ionic and organic pollutants for recycling space mission wastewater. Seven candidate RO membranes were compared using a batch stirred cell to determine the membrane flux and the solute rejection for synthetic space mission wastewaters. Even though the urea molecule is larger than ions such as Na+, Cl-, and NH4+, the rejection of urea is lower. This indicates that the chemical interaction between solutes and the membrane is more important than the size exclusion effect. Low pressure reverse osmosis (LPRO) membranes appear to be most desirable because of their high permeate flux and rejection. Solute rejection is dependent on the shear rate, indicating the importance of concentration polarization. A simple transport model based on the solution-diffusion model incorporating concentration polarization is used to interpret the experimental results and predict rejection over a range of operating conditions. Grant numbers: NAG 9-1053.

Performance of high-recovery recycling reverse osmosis with wash water

NASA Technical Reports Server (NTRS)

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.)

Closure of Regenerative Life Support Systems: Results of the Lunar-Mars Life Support Test Project

NASA Technical Reports Server (NTRS)

Barta, Daniel; Henninger, D.; Edeen, M.; Lewis, J.; Smth, F.; Verostko, C.

2006-01-01

Future long duration human exploration missions away from Earth will require closed-loop regenerative life support systems to reduce launch mass, reduce dependency on resupply and increase the level of mission self sufficiency. Such systems may be based on the integration of biological and physiocochemical processes to produce potable water, breathable atmosphere and nutritious food from metabolic and other mission wastes. Over the period 1995 to 1998 a series of ground-based tests were conducted at the National Aeronautics and Space Administration, Johnson Space Center, to evaluate the performance of advanced closed-loop life support technologies with real human metabolic and hygiene loads. Named the Lunar-Mars Life Support Test Project (LMLSTP), four integrated human tests were conducted with increasing duration, complexity and closure. The first test, LMLSTP Phase I, was designed to demonstrate the ability of higher plants to revitalize cabin atmosphere. A single crew member spent 15 days within an atmospherically closed chamber containing 11.2 square meters of actively growing wheat. Atmospheric carbon dioxide and oxygen levels were maintained by control of the rate of photosynthesis through manipulation of light intensity or the availability of carbon dioxide and included integrated physicochemical systems. During the second and third tests, LMLSTP Phases II & IIa, four crew members spent 30 days and 60 days, respectively, in a larger sealed chamber. Advanced physicochemical life support hardware was used to regenerate the atmosphere and produce potable water from wastewater. Air revitalization was accomplished by using a molecular sieve and a Sabatier processor for carbon dioxide absorption and reduction, respectively, with oxygen generation performed by water hydrolysis. Production of potable water from wastewater included urine treatment (vapor compression distillation), primary treatment (ultrafiltration/reverse osmosis and multi-filtration) and post processing. For the Phase II test the water recovery rate ranged from 95 to 98%, depending on the processor. LMLSTP Phase III, the fourth test of the series, had a duration of 91 days and included four crew members. The test demonstrated an integration of physicochemical and biological technologies for air revitalization, water recovery and waste processing. Wheat supplemented the physicochemical air revitalization systems by providing approximately 25% of the oxygen required for the 4-person crew. The water recovery system included immobilized cell and trickling filter bioreactors for primary water treatment, reverse osmosis and air evaporation systems for secondary water treatment, followed by post processing. The 8 day initial supply of water was recycled through the chamber and crew 10 times over the course of the test. Grain from the wheat together with fresh lettuce from a small growth chamber within the crew chamber provided supplementation to the stored food system, but at a level less than 5% of the crew s caloric requirement. An incinerator was used to demonstrate mineralization of the crew s solid waste, with the combustion products (mainly carbon dioxide) returned to the wheat for conversion to oxygen.

Zero Liquid Discharge (ZLD) System for Flue-Gas Derived Water From Oxy-Combustion Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sivaram Harendra; Danylo Oryshchyn; Thomas Ochs

2011-10-16

Researchers at the National Energy Technology Laboratory (NETL) located in Albany, Oregon, have patented a process - Integrated Pollutant Removal (IPR) that uses off-the-shelf technology to produce a sequestration ready CO{sub 2} stream from an oxy-combustion power plant. Capturing CO{sub 2} from fossil-fuel combustion generates a significant water product which can be tapped for use in the power plant and its peripherals. Water condensed in the IPR{reg_sign} process may contain fly ash particles, sodium (from pH control), and sulfur species, as well as heavy metals, cations and anions. NETL is developing a treatment approach for zero liquid discharge while maximizingmore » available heat from IPR. Current treatment-process steps being studied are flocculation/coagulation, for removal of cations and fine particles, and reverse osmosis, for anion removal as well as for scavenging the remaining cations. After reverse osmosis process steps, thermal evaporation and crystallization steps will be carried out in order to build the whole zero liquid discharge (ZLD) system for flue-gas condensed wastewater. Gypsum is the major product from crystallization process. Fast, in-line treatment of water for re-use in IPR seems to be one practical step for minimizing water treatment requirements for CO{sub 2} capture. The results obtained from above experiments are being used to build water treatment models.« less

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

DTIC Science & Technology

1986-02-01

Data-for ASsessingHealthRISKS In Potential Theaters ~ of Operation forU,5. Mil-itary._orces. Jf-jr cLAss t:cAToN 9; r-.$ ’AGg UNCLASSIFIED Volume 7...Bypass, Potable-Water Disinfection,_ and Water-Quality Analysis Techniques; and Vol. 9, Data for Assessing Health Risks in Potential Theaters of Operation ...cleaning the RO elements, with objectives of improving solute rejection and reducing operating pressure. The most common method is to flush citric acid

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

PubMed

Jiang, Yaxin; Liang, Jiaming; Liu, Yang

2016-01-01

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

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

PubMed

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.

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

PubMed

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.

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

PubMed

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.

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

PubMed

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

2013-12-01

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

Reconnaissance samplings and characterization of aquatic humic substances at the Yuma Desalting Test Facility, Arizona

USGS Publications Warehouse

Malcolm, R.L.; Wershaw, R. L.; Thurman, E.M.; Aiken, G.R.; Pinckney, D.J.; Kaakinen, J.

1981-01-01

Smectite clay minerals were found to be the principal compound on the surface of the cellulose-acetate, reverse-osmosis membranes at the Yuma Desalting Test Facility. These clay minerals were not present in the pumped ground water, but were blown into the conveyance canal from adjacent soils. Humic substances from the water and suspended sediments were associated with the clay films on the membrane, but no definitive results concerning their role in fouling were achieved. Microbial fouling is believed to be only a minor aspect of membrane fouling. Chemical and physical changes in humic substances were extensively studied at four points in the water-treatment process. Humic substances accounted for the largest component (over 25 percent) of organic constituents. Humic substances in the canal source water were similar to other aquatic humic substances present in natural waters. During the treatment process, these substances are brominated and decolorized. The effect of these halogenated humic substances on membrane fouling is unclear, but their presence in the reverse-osmosis product water and reverse-osmosis reject brine, along with volatile trihalomethanes, has led to environmental concerns. (USGS)

Optimization of the elution buffer and concentration method for detecting hepatitis E virus in swine liver using a nested reverse transcription-polymerase chain reaction and real-time reverse transcription-polymerase chain reaction.

PubMed

Son, Na Ry; Seo, Dong Joo; Lee, Min Hwa; Seo, Sheungwoo; Wang, Xiaoyu; Lee, Bog-Hieu; Lee, Jeong-Su; Joo, In-Sun; Hwang, In-Gyun; Choi, Changsun

2014-09-01

The aim of this study was to develop an optimal technique for detecting hepatitis E virus (HEV) in swine livers. Here, three elution buffers and two concentration methods were compared with respect to enhancing recovery of HEV from swine liver samples. Real-time reverse transcription-polymerase chain reaction (RT-PCR) and nested RT-PCR were performed to detect HEV RNA. When phosphate-buffered saline (PBS, pH 7.4) was used to concentrate HEV in swine liver samples using ultrafiltration, real-time RT-PCR detected HEV in 6 of the 26 samples. When threonine buffer was used to concentrate HEV using polyethylene glycol (PEG) precipitation and ultrafiltration, real-time RT-PCR detected HEV in 1 and 3 of the 26 samples, respectively. When glycine buffer was used to concentrate HEV using ultrafiltration and PEG precipitation, real-time RT-PCR detected HEV in 1 and 3 samples of the 26 samples, respectively. When nested RT-PCR was used to detect HEV, all samples tested negative regardless of the type of elution buffer or concentration method used. Therefore, the combination of real-time RT-PCR and ultrafiltration with PBS buffer was the most sensitive and reliable method for detecting HEV in swine livers. Copyright © 2014 Elsevier B.V. All rights reserved.

Chemical osmosis, reverse chemical osmosis, and the origin of subsurface brines

NASA Astrophysics Data System (ADS)

Graf, Donald L.

1982-08-01

Calculations using recently-tabulated values of density and osmotic coefficient for NaCl-H 2O indicate that overpressuring is more than adequate to overcome chemical osmosis and drive reverse chemical osmosis in sedimentary sequences. The best-demonstrated overpressuring mechanism is the rapid deposition of fine-grained sediments. The dehydration of gypsum contributes to overpressuring for brief time intervals at shallow depths, whereas water evolved during the protracted conversion of smectite to illite is probably a subordinate, but continuing contributor to overpressuring at greater depth. Occurrences of overpressuring in sedimentary sections older than Cretaceous indicate that post-depositional mechanisms such as tectonic compression and aquathermal pressuring must also operate. The latter may be of major importance in geothermal areas with adequate low-permeability seals, and a nontrivial contributor in areas of normal geothermal gradient because of shales that sharply decrease normal fluid flow. The strongest arguments for the importance to present-day brine compositions of membrane concentration of sea-water solutes are (1) the correlation of δD values of water molecules of pore fluid with those of local meteoric water, (2) the need for major sources of Mg 2+ and Cl - in apparently evaporite-free basins. Even where dissolution of halite is a major contributor of solute, reverse chemical osmosis still operates to leak relatively dilute water. Of the associated diagenetic chemical reactions, that of Mg 2+ with limestone to form dolomite is particularly effective in generating concentrated Cl - brines rich in Ca 2+. It decreases the concentration of Mg 2+, increases that of Ca 2+, and decreases those of both SO 42- and CO 32- by precipitating CaCO 3 and CaSO 4 because of the Ca 2+ common-ion effect.

Method for the preparation of thin-skinned asymmetric reverse osmosis membranes and products thereof

NASA Technical Reports Server (NTRS)

Wydeven, T. J. (Inventor); Katz, M. G.

1984-01-01

A method for preparing water insoluble asymmetric membranes from water soluble polymers is discussed. The process involves casting a film of the polymer, partially drying it, and then contacting it with a concentrated solution of a transition metal salt. The transition metal ions render the polymer insoluable and are believed to form a complex with it. Optionally, the polymer is crosslinked with heat or radiation. The most preferred polymer is poly(vinyl alcohol). The most preferred complexing salt is copper sulfate. The process and the metal ion linked membranes are discussed. The membranes are reverse osmosis membranes.

Evaluation of contaminant removal of reverse osmosis and advanced oxidation in full-scale operation by combining passive sampling with chemical analysis and bioanalytical tools.

PubMed

Escher, Beate I; Lawrence, Michael; Macova, Miroslava; Mueller, Jochen F; Poussade, Yvan; Robillot, Cedric; Roux, Annalie; Gernjak, Wolfgang

2011-06-15

Advanced water treatment of secondary treated effluent requires stringent quality control to achieve a water quality suitable for augmenting drinking water supplies. The removal of micropollutants such as pesticides, industrial chemicals, endocrine disrupting chemicals (EDC), pharmaceuticals, and personal care products (PPCP) is paramount. As the concentrations of individual contaminants are typically low, frequent analytical screening is both laborious and costly. We propose and validate an approach for continuous monitoring by applying passive sampling with Empore disks in vessels that were designed to slow down the water flow, and thus uptake kinetics, and ensure that the uptake is only marginally dependent on the chemicals' physicochemical properties over a relatively narrow molecular size range. This design not only assured integrative sampling over 27 days for a broad range of chemicals but also permitted the use of a suite of bioanalytical tools as sum parameters, representative of mixtures of chemicals with a common mode of toxic action. Bioassays proved to be more sensitive than chemical analysis to assess the removal of organic micropollutants by reverse osmosis, followed by UV/H₂O₂ treatment, as many individual compounds fell below the quantification limit of chemical analysis, yet still contributed to the observed mixture toxicity. Nonetheless in several cases, the responses in the bioassays were also below their quantification limits and therefore only three bioassays were evaluated here, representing nonspecific toxicity and two specific end points for estrogenicity and photosynthesis inhibition. Chemical analytical techniques were able to quantify 32 pesticides, 62 PCPPs, and 12 EDCs in reverse osmosis concentrate. However, these chemicals could explain only 1% of the nonspecific toxicity in the Microtox assay in the reverse osmosis concentrate and 0.0025% in the treated water. Likewise only 1% of the estrogenic effect in the E-SCREEN could be explained by the quantified EDCs after reverse osmosis. In comparison, >50% of the estrogenic effect can typically be explained in sewage. Herbicidal activity could be fully explained by chemical analysis as the sampling period coincided with an illegal discharge and two herbicides dominated the mixture effect. The mass balance of the reverse osmosis process matched theoretical expectations for both chemical analysis and bioanalytical tools. Overall the investigated treatment train removed >97% estrogenicity, >99% herbicidal activity, and >96% baseline toxicity, confirming the suitability of the treatment train for polishing water for indirect potable reuse. The product water was indistinguishable from local tap water in all three bioassays. This study demonstrates the suitability and robustness of passive sampling linked with bioanalytical tools for semicontinuous monitoring of advanced water treatment with respect to micropollutant removal.

Analysis of a Wave-Powered, Reverse-Osmosis System and its Economic Availability in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Yi-Hsiang; Jenne, Dale S

A wave energy converter (WEC) system has the potential to convert the wave energy resource directly into the high-pressure flow that is needed by the desalination system to permeate saltwater through the reverse-osmosis membrane to generate clean water. In this study, a wave-to-water numerical model was developed to investigate the potential use of a wave-powered desalination system (WPDS) for water production in the United States. The model was developed by coupling a time-domain radiation-and-diffraction-method-based numerical tool (WEC-Sim) for predicting the hydrodynamic performance of WECs with a solution-diffusion model that was used to simulate the reverse-osmosis process. To evaluate the feasibilitymore » of the WPDS, the wave-to-water numerical model was applied to simulate a desalination system that used an oscillating surge WEC device to pump seawater through the system. The annual water production was estimated based on the wave resource at a reference site on the coast of northern California to investigate the potential cost of water in that area, where the cost of water and electricity is high compared to other regions. In the scenario evaluated, for a 100-unit utility-scale array, the estimated levelized cost of energy for these WECs is about 3-6 times the U.S.'s current, unsubsidized electricity rates. However, with clean water as an end product and by directly producing pressurized water with WECs, rather than electricity as an intermediary, it is presently only 12% greater than typical water cost in California. This study suggests that a WEC array that produces water may be a viable, near-term solution to the nation's water supply, and the niche application of the WPDS may also provide developers with new opportunities to further develop technologies that benefit both the electric and drinking water markets.« less

Analysis of a Wave-Powered, Reverse-Osmosis System and Its Economic Availability in the United States: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Yi-Hsiang; Jenne, Dale S

A wave energy converter (WEC) system has the potential to convert the wave energy resource directly into the high-pressure flow that is needed by the desalination system to permeate saltwater through the reverse-osmosis membrane to generate clean water. In this study, a wave-to-water numerical model was developed to investigate the potential use of a wave-powered desalination system (WPDS) for water production in the United States. The model was developed by coupling a time-domain radiation-and-diffraction-method-based numerical tool (WEC-Sim) for predicting the hydrodynamic performance of WECs with a solution-diffusion model that was used to simulate the reverse-osmosis process. To evaluate the feasibilitymore » of the WPDS, the wave-to-water numerical model was applied to simulate a desalination system that used an oscillating surge WEC device to pump seawater through the system. The annual water production was estimated based on the wave resource at a reference site on the coast of northern California to investigate the potential cost of water in that area, where the cost of water and electricity is high compared to other regions. In the scenario evaluated, for a 100-unit utility-scale electricity-producing array, the estimated levelized cost of energy for these WECs is about 3-6 times the U.S.'s current, unsubsidized electricity rates. However, with clean water as an end product and by directly producing pressurized water with WECs, rather than electricity as an intermediary, it is presently only 12 percent greater than typical water cost in California. This study suggests that a WEC array that produces water may be a viable, near-term solution to the nation's water supply, and the niche application of the WPDS may also provide developers with new opportunities to further develop technologies that benefit both the electric and drinking water markets.« less

Heterotrophic monitoring at a drinking water treatment plant by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry after different drinking water treatments.

PubMed

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

2017-10-01

The aim of this work was to assess the suitability of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) for routine heterotrophic monitoring in a drinking water treatment plant. Water samples were collected from raw surface water and after different treatments during two campaigns over a 1-year period. Heterotrophic bacteria were studied and isolates were identified by MALDI-TOF MS. Moreover, the diversity index and the coefficient of population similarity were also calculated using biochemical fingerprinting of the populations studied. MALDI-TOF MS enabled us to characterize and detect changes in the bacterial community composition throughout the water treatment plant. Raw water showed a large and diverse population which was slightly modified after initial treatment steps (sand filtration and ultrafiltration). Reverse osmosis had a significant impact on the microbial diversity, while the final chlorination step produced a shift in the composition of the bacterial community. Although MALDI-TOF MS could not identify all the isolates since the available MALDI-TOF MS database does not cover all the bacterial diversity in water, this technique could be used to monitor bacterial changes in drinking water treatment plants by creating a specific protein profile database for tracking purposes.

Incorporation of Graphene-Related Carbon Nanosheets in Membrane Fabrication for Water Treatment: A Review

PubMed Central

Lawler, Jenny

2016-01-01

The minimization of the trade-off between the flux and the selectivity of membranes is a key area that researchers are continually working to optimise, particularly in the area of fabrication of novel membranes. Flux versus selectivity issues apply in many industrial applications of membranes, for example the unwanted diffusion of methanol in fuel cells, retention of valuable proteins in downstream processing of biopharmaceuticals, rejection of organic matter and micro-organisms in water treatment, or salt permeation in desalination. The incorporation of nanosheets within membrane structures can potentially lead to enhancements in such properties as the antifouling ability, hydrophilicy and permeability of membranes, with concomitant improvements in the flux/selectivity balance. Graphene nanosheets and derivatives such as graphene oxide and reduced graphene oxide have been investigated for this purpose, for example inclusion of nanosheets within the active layer of Reverse Osmosis or Nanofiltration membranes or the blending of nanosheets as fillers within Ultrafiltration membranes. This review summarizes the incorporation of graphene derivatives into polymeric membranes for water treatment with a focus on a number of industrial applications, including desalination and pharmaceutical removal, where enhancement of productivity and reduction in fouling characteristics have been afforded by appropriate incorporation of graphene derived nanosheets during membrane fabrication. PMID:27999364

How different is the composition of the fouling layer of wastewater reuse and seawater desalination RO membranes?

PubMed

Khan, Muhammad Tariq; Busch, Markus; Molina, Veronica Garcia; Emwas, Abdul-Hamid; Aubry, Cyril; Croue, Jean-Philippe

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Experimental investigation of oily wastewater treatment using combined membrane systems.

PubMed

Salahi, A; Mohammadi, T

2010-01-01

Investigations were carried out for purification of oily wastewater by a combined of ultrafiltration/reverse osmosis (UF/RO) processes. Laboratory-scale UF using polysulfone (PS) and polyacrylonitrile (PAN) membranes were employed with typical oily wastewater collected from API unit of Tehran refinery. The PAN membrane showed higher rejection, more permeation flux and less fouling resistance than the PS membrane. Both membranes produced permeate with oil and grease contents generally less than 5 ppm. Rejection of chemical oxygen demand (COD) and biological oxygen demand (BOD5) were found to be 65% for UF treatment. In this work, Hermia's models were used to investigate the fouling mechanism involved in UF of the oily wastewater. The results showed that the best fit to experimental data corresponds to the cake layer formation model followed by the intermediate blocking model for both the UF membranes. For further treatment of the UF permeates, RO was applied using a thin film composite polyamide membrane. The rejection of COD, BOD5 and total dissolved solid (TDS) after UF/RO treatment increased up to 98%, 98% and 95%, respectively. The results showed that the final permeate has very high quality and even better than that is currently introduced to the cooling towers in Tehran refinery.

Determination of radon concentration in water using RAD7 with RAD H{sub 2}O accessories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malik, M. F. I.; Rabaiee, N. A.; Jaafar, M. S.

In the last decade, the radon issue has become one of the major problems of radiation protection. Radon exposure occurs when using water for showering, washing dishes, cooking and drinking water. RAD7 and Rad H20 accessories were used in order to measure radon concentration in water sample. In this study, four types of water were concerns which are reverse osmosis (drinking water), mineral water, tap water and well water. Reverse osmosis (drinking water) and mineral water were bought from the nearest supermarket while tap water and well water were taken from selected areas of Pulau Pinang and Kedah. Total 20more » samples were taken with 5 samples for each type of water. The measured radon concentration ranged from 2.9±2.9 to 79.5±17 pCi/L, 2.9±2.9 to 67.8±16 pCi/L, 15.97±7 to 144.25±24 pCi/L and 374.89±37 to 6409.03±130 pCi/L in reverse osmosis (drinking water), mineral water, tap water and well water. Well water has the highest radon compared to others. It was due to their geological element such as granite. Results for all types of water are presented and compared with maximum contamination limit (MCL) recommended by United State Environmental Protection Agency (USEPA) which is 300pCi/L. Reverse osmosis water, mineral water and tap water were fall below MCL. However, well water was exceeded maximum level that was recommended. Thus, these findings were suggested that an action should be taken to reduce radon concentration level in well water as well as reduce a health risk towards the public.« less

Comparison of the removal of hydrophobic trace organic contaminants by forward osmosis and reverse osmosis.

PubMed

Xie, Ming; Nghiem, Long D; Price, William E; Elimelech, Menachem

2012-05-15

We compared the rejection behaviours of three hydrophobic trace organic contaminants, bisphenol A, triclosan and diclofenac, in forward osmosis (FO) and reverse osmosis (RO). Using erythritol, xylose and glucose as inert reference organic solutes and the membrane pore transport model, the mean effective pore size of a commercial cellulose-based FO membrane was estimated to be 0.74 nm. When NaCl was used as the draw solute, at the same water permeate flux of 5.4 L/m(2) h (or 1.5 μm/s), the adsorption of all three compounds to the membrane in the FO mode was consistently lower than that in the RO mode. Rejection of bisphenol A and diclofenac were higher in the FO mode compared to that in the RO mode. Because the molecular width of triclosan was larger than the estimated mean effective membrane pore size, triclosan was completely rejected by the membrane and negligent difference between the FO and RO modes could be observed. The difference in the separation behaviour of these hydrophobic trace organics in the FO (using NaCl the draw solute) and RO modes could be explained by the phenomenon of retarded forward diffusion of solutes. The reverse salt flux of NaCl hinders the pore diffusion and subsequent adsorption of the trace organic compounds within the membrane. The retarded forward diffusion effect was not observed when MgSO(4) and glucose were used as the draw solutes. The reverse flux of both MgSO(4) and glucose was negligible and thus both adsorption and rejection of BPA in the FO mode were identical to those in the RO mode. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Hydrophilic, bactericidal nanoheater-enabled reverse osmosis membranes to improve fouling resistance.

PubMed

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.

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

PubMed

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.

Comparison of MFI-UF constant pressure, MFI-UF constant flux and Crossflow Sampler-Modified Fouling Index Ultrafiltration (CFS-MFI UF).

PubMed

Sim, Lee Nuang; Ye, Yun; Chen, Vicki; Fane, Anthony G

2011-02-01

Understanding the foulant deposition mechanism during crossflow filtration is critical in developing indices to predict fouling propensity of feed water for reverse osmosis (RO). Factors affecting the performance on different fouling indices such as MFI-UF constant pressure, MFI-UF constant flux and newly proposed fouling index, CFS-MFI(UF) were investigated. Crossflow Sampler-Modified Fouling Index Ultrafiltration (CFS-MFI(UF)) utilises a typical crossflow unit to simulate the hydrodynamic conditions in the actual RO units followed by a dead-end unit to measure the fouling propensity of foulants. CFS-MFI(UF) was found sensitive to crossflow velocity. The crossflow velocity in the crossflow sampler unit influences the particle concentration and the particle size distribution in its permeate. CFS-MFI(UF) was also found sensitive to the permeate flux of both CFS and the dead-end cell. To closely simulate the hydrodynamic conditions of a crossflow RO unit, the flux used for CFS-MFI(UF) measurement was critical. The best option is to operate both the CFS and dead-end permeate flux at flux which is normally operated at industry RO units (∼20 L/m(2)h), but this would prolong the test duration excessively. In this study, the dead-end flux was accelerated by reducing the dead-end membrane area while maintaining the CFS permeate flux at 20 L/m(2)h. By doing so, a flux correction factor was investigated and applied to correlate the CFS-MFI(UF) measured at dead-end flux of 120 L/m(2)h to CFS-MFI(UF) measured at dead-end flux of 20 L/m(2)h for RO fouling rate prediction. Using this flux correction factor, the test duration of CFS-MFI(UF) can be shortened from 15 h to 2h. © 2010 Elsevier Ltd. All rights reserved.

Nanofiber Filters Eliminate Contaminants

NASA Technical Reports Server (NTRS)

2009-01-01

With support from Phase I and II SBIR funding from Johnson Space Center, Argonide Corporation of Sanford, Florida tested and developed its proprietary nanofiber water filter media. Capable of removing more than 99.99 percent of dangerous particles like bacteria, viruses, and parasites, the media was incorporated into the company's commercial NanoCeram water filter, an inductee into the Space Foundation's Space Technology Hall of Fame. In addition to its drinking water filters, Argonide now produces large-scale nanofiber filters used as part of the reverse osmosis process for industrial water purification.

Assessment of Oil Pretreatment Technologies to Improve Performance of Reverse Osmosis Systems

DTIC Science & Technology

1992-06-19

CVHIZ H H 14 1C H2 NH 1 cnxz I I C, C-C - C-H H H 1 H-C-H N NAPHTHENES Cyclhe zaoa. C Hsa CH, CHa CnHZn CH2 C > CH, CH, CH2 AROMATICS (no general...aromatics, and naphthenes , plus related hydrocarbon derivatives of sulfur, oxygen, and nitrogen that were not removed by refining. Olefins are absent...magnesium (Davidson, 1978). Lime, caustic soda or magnesium in the oxide or carbonate form are usually used. Figure 3.14. presents a typical flow diagram

Culturable bacterial diversity from a feed water of a reverse osmosis system, evaluation of biofilm formation and biocontrol using phages.

PubMed

Belgini, D R B; Dias, R S; Siqueira, V M; Valadares, L A B; Albanese, J M; Souza, R S; Torres, A P R; Sousa, M P; Silva, C C; De Paula, S O; Oliveira, V M

2014-10-01

Biofilm formation on reverse osmosis (RO) systems represents a drawback in the application of this technology by different industries, including oil refineries. In RO systems the feed water maybe a source of microbial contamination and thus contributes for the formation of biofilm and consequent biofouling. In this study the planktonic culturable bacterial community was characterized from a feed water of a RO system and their capacities were evaluated to form biofilm in vitro. Bacterial motility and biofilm control were also analysed using phages. As results, diverse Protobacteria, Actinobacteria and Bacteroidetes were identified. Alphaproteobacteria was the predominant group and Brevundimonas, Pseudomonas and Mycobacterium the most abundant genera. Among the 30 isolates, 11 showed at least one type of motility and 11 were classified as good biofilm formers. Additionally, the influence of non-specific bacteriophage in the bacterial biofilms formed in vitro was investigated by action of phages enzymes or phage infection. The vB_AspP-UFV1 (Podoviridae) interfered in biofilm formation of most tested bacteria and may represent a good alternative in biofilm control. These findings provide important information about the bacterial community from the feed water of a RO system that may be used for the development of strategies for biofilm prevention and control in such systems.

Use of reverse osmosis membranes to remove perfluorooctane sulfonate (PFOS) from semiconductor wastewater.

PubMed

Tang, Chuyang Y; Fu, Q Shiang; Robertson, A P; Criddle, Craig S; Leckie, James O

2006-12-01

Perfluorooctane sulfonate (PFOS) and related substances are persistent, bioaccumulative, and toxic, and thus of substantial environmental concern. PFOS is an essential photolithographic chemical in the semiconductor industry with no substitutes yet identified. The industry seeks effective treatment technologies. The feasibility of using reverse osmosis (RO) membranes for treating semiconductor wastewater containing PFOS has been investigated. Commercial RO membranes were characterized in terms of permeability, salt rejection, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and membrane surface zeta potential (streaming potential measurements). Filtration tests were performed to determine the membrane flux and PFOS rejection. Over a wide range of feed concentrations (0.5 - 1500 ppm), the RO membranes generally rejected 99% or more of the PFOS. Rejection was better for tighter membranes, but was not affected by membrane zeta potential. Flux decreased with increasing PFOS concentration. While the flux reduction was severe for a loose RO membrane probably due to its higher initial flux, very stable flux was maintained for tighter membranes. At a very high feed concentration (about 500 ppm), all the membranes exhibited an identical stable flux. Isopropyl alcohol, present in some semiconductor wastewaters, had a detrimental effect on membrane flux. Where present it needs to be removed from the wastewater prior to using RO membranes.

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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.

Fast deswelling of nanocomposite polymer hydrogels via magnetic field-induced heating for emerging FO desalination.

PubMed

Razmjou, Amir; Barati, Mohammad Reza; Simon, George P; Suzuki, Kiyonori; Wang, Huanting

2013-06-18

Freshwater shortage is one of the most pressing global issues. Forward osmosis (FO) desalination technology is emerging for freshwater production from saline water, which is potentially more energy-efficient than the current reverse osmosis process. However, the lack of a suitable draw solute is the major hurdle for commercial implementation of the FO desalination technology. We have previously reported that thermoresponsive hydrogels can be used as the draw agent for a FO process, and this new hydrogel-driven FO process holds promise for further development for practical application. In the present work, magnetic field-induced heating is explored for the purpose of developing a more effective way to recover water from swollen hydrogel draw agents. The composite hydrogel particles are prepared by copolymerization of sodium acrylate and N-isopropylacrylamide in the presence of magnetic nanoparticles (γ-Fe2O3, <50 nm). The results indicate that the magnetic heating is an effective and rapid method for dewatering of hydrogels by generating the heat more uniformly throughout the draw agent particles, and thus, a dense skin layer commonly formed via conventional heating from the outside of the particle is minimized. The FO dewatering performance is affected by the loading of magnetic nanoparticles and magnetic field intensity. Significantly enhanced liquid water recovery (53%) is achieved under magnetic heating, as opposed to only around 7% liquid water recovery obtained via convection heating. Our study shows that the magnetic heating is an attractive alternative stimulus for the extraction of highly desirable liquid water from the draw agent in the polymer hydrogel-driven forward osmosis process.

A Feasibility Study of Pressure Retarded Osmosis Power Generation System based on Measuring Permeation Volume using Reverse Osmosis Membrane

NASA Astrophysics Data System (ADS)

Enomoto, Hiroshi; Fujitsuka, Masashi; Hasegawa, Tomoyasu; Kuwada, Masatoshi; Tanioka, Akihiko; Minagawa, Mie

Pressure Retarded Osmosis (PRO) power generation system is a hydroelectric power system which utilize permeation flow through a semi-permeable membrane. Permeation flow is generated by potential energy of salinity difference between sea water and fresh water. As membrane cost is expensive, permeation performance of membrane must be higher to realize PRO system. We have investigated Reverse Osmosis (RO) membrane products as semi-permeable membrane and measured permeation volume of a few products. Generation power by membrane area calculated from permeation volume is about 0.62W/m2. But by our improvements (more salt water volume, spacer of fresh water channel with a function of discharging concentrated salinity, extra low pressure type of membrane, washing support layer of membrane when generation power reduces to half), generation power may be 2.43W/m2. Then power system cost is about 4.1 million yen/kW. In addition, if support layer of membrane makes thinner and PRO system is applied to the equipment that pumping power on another purpose is avairable (wastewater treatment plant located at the seaside, thermal and nuclear power plant or sea water desalination plant), generation power may be more. By these improvements PRO system may be able to realize at the cost close to photovoltaic power system.

Rotating Reverse Osmosis for Wastewater Reuse

NASA Technical Reports Server (NTRS)

Lueptow, Richard M.; Yoon, Yeomin; Pederson, Cynthia

2004-01-01

Membrane filtration such as Reverse Osmosis (RO) removes ions, proteins, and organic chemicals which are generally very difficult to remove using conventional treatment. Moreover, membrane is an absolute filtration method, so its treatment efficiency and performance are stable and predictable. We are currently working on the development of rotating RO membrane system. Dynamic rotating membrane filtration, which can produce a high shear rate, may be helpful to obtain high rejection of organic pollutants.The goal of our current work is to improve the flux of the device by increasing pressure by a factor of 3 to 4. In addition, the rejections for a wider variety of inorganic and organic compounds typically found in space mission wastewater are measured.

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

PubMed Central

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

Water Recovery from Advanced Water Purification Facility Reverse Osmosis Concentrate by Photobiological Treatment Followed by Secondary Reverse Osmosis.

PubMed

Ikehata, Keisuke; Zhao, Yuanyuan; Kulkarni, Harshad; Li, Yuan; Snyder, Shane A; Ishida, Kenneth P; Anderson, Michael A

2018-06-19

Reverse osmosis (RO)-based desalination and advanced water purification facilities have inherent challenges associated with concentrate management and disposal. Although enhanced permeate recovery and concentrate minimization are desired, membrane scaling due to inorganic constituents such as silica, calcium, phosphate, and iron hinders the process. To solve this problem, a new diatom-based photobiological process has been developed to remove these scaling constituents by biological uptake and precipitation. In this study, RO concentrate samples were collected from a full-scale advanced water reclamation facility in California and were treated in 3.8- and 57-L photobioreactors inoculated with a brackish water diatom Pseudostaurosira trainorii PEWL001 using light-emitting diode bulbs or natural sunlight as a light source. The photobiological treatment removed 95% of reactive silica and 64% of calcium and enabled additional water recovery using a secondary RO at a recovery rate up to 66%. This represents 95% overall recovery including 85% recovery in the primary RO unit. In addition to the scaling constituents, the photobiological treatment removed twelve pharmaceuticals and personal care products, as well as N-nitrosodimethylamine, from RO concentrate samples primarily via photolysis. This novel approach has a strong potential for application to brackish water desalination and advanced water purification in arid and semi-arid areas.

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

NASA Astrophysics Data System (ADS)

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

2018-02-01

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

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

PubMed

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.

Relationship between performance deterioration of a polyamide reverse osmosis membrane used in a seawater desalination plant and changes in its physicochemical properties.

PubMed

Suzuki, Tasuma; Tanaka, Ryohei; Tahara, Marina; Isamu, Yuya; Niinae, Masakazu; Lin, Lin; Wang, Jingbo; Luh, Jeanne; Coronell, Orlando

2016-09-01

While it is known that the performance of reverse osmosis membranes is dependent on their physicochemical properties, the existing literature studying membranes used in treatment facilities generally focuses on foulant layers or performance changes due to fouling, not on the performance and physicochemical changes that occur to the membranes themselves. In this study, the performance and physicochemical properties of a polyamide reverse osmosis membrane used for three years in a seawater desalination plant were compared to those of a corresponding unused membrane. The relationship between performance changes during long-term use and changes in physicochemical properties was evaluated. The results showed that membrane performance deterioration (i.e., reduced water flux, reduced contaminant rejection, and increased fouling propensity) occurred as a result of membrane use in the desalination facility, and that the main physicochemical changes responsible for performance deterioration were reduction in PVA coating coverage and bromine uptake by polyamide. The latter was likely promoted by oxidant residual in the membrane feed water. Our findings indicate that the optimization of membrane materials and processes towards maximizing the stability of the PVA coating and ensuring complete removal of oxidants in feed waters would minimize membrane performance deterioration in water purification facilities. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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.

Production of demineralized water for use in thermal power stations by advanced treatment of secondary wastewater effluent.

PubMed

Katsoyiannis, Ioannis A; Gkotsis, Petros; Castellana, Massimo; Cartechini, Fabricio; Zouboulis, Anastasios I

2017-04-01

The operation and efficiency of a modern, high-tech industrial full-scale water treatment plant was investigated in the present study. The treated water was used for the supply of the boilers, producing steam to feed the steam turbine of the power station. The inlet water was the effluent of municipal wastewater treatment plant of the city of Bari (Italy). The treatment stages comprised (1) coagulation, using ferric chloride, (2) lime softening, (3) powdered activated carbon, all dosed in a sedimentation tank. The treated water was thereafter subjected to dual-media filtration, followed by ultra-filtration (UF). The outlet of UF was subsequently treated by reverse osmosis (RO) and finally by ion exchange (IX). The inlet water had total organic carbon (TOC) concentration 10-12 mg/L, turbidity 10-15 NTU and conductivity 3500-4500 μS/cm. The final demineralized water had TOC less than 0.2 mg/L, turbidity less than 0.1 NTU and conductivity 0.055-0.070 μS/cm. Organic matter fractionation showed that most of the final DOC concentration consisted of low molecular weight neutral compounds, while other compounds such as humic acids or building blocks were completely removed. It is notable that this plant was operating under "Zero Liquid Discharge" conditions, implementing treatment of any generated liquid waste. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of different wastewater treatments for removal of selected endocrine-disruptors from paper mill wastewaters.

PubMed

Balabanič, Damjan; Hermosilla, Daphne; Merayo, Noemí; Klemenčič, Aleksandra Krivograd; Blanco, Angeles

2012-01-01

There is increasing concern about chemical pollutants that have the ability to mimic hormones, the so-called endocrine-disrupting compounds (EDCs). One of the main reasons for concern is the possible effect of EDCs on human health. EDCs may be released into the environment in different ways, and one of the most significant sources is industrial wastewater. The main objective of this research was to evaluate the treatment performance of different wastewater treatment procedures (biological treatment, filtration, advanced oxidation processes) for the reduction of chemical oxygen demand and seven selected EDCs (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate, bisphenol A and nonylphenol) from wastewaters from a mill producing 100 % recycled paper. Two pilot plants were running in parallel and the following treatments were compared: (i) anaerobic biological treatment followed by aerobic biological treatment, ultrafiltration and reverse osmosis (RO), and (ii) anaerobic biological treatment followed by membrane bioreactor and RO. Moreover, at lab-scale, four different advanced oxidation processes (Fenton reaction, photo-Fenton reaction, photocatalysis with TiO(2), and ozonation) were applied. The results indicated that the concentrations of selected EDCs from paper mill wastewaters were effectively reduced (100 %) by both combinations of pilot plants and photo-Fenton oxidation (98 %), while Fenton process, photocatalysis with TiO(2) and ozonation were less effective (70 % to 90 %, respectively).

Bacterial community and groundwater quality changes in an anaerobic aquifer during groundwater recharge with aerobic recycled water.

PubMed

Ginige, Maneesha P; Kaksonen, Anna H; Morris, Christina; Shackelton, Mark; Patterson, Bradley M

2013-09-01

Managed aquifer recharge offers the opportunity to manage groundwater resources by storing water in aquifers when in surplus and thus increase the amount of groundwater available for abstraction during high demand. The Water Corporation of Western Australia (WA) is undertaking a Groundwater Replenishment Trial to evaluate the effects of recharging aerobic recycled water (secondary treated wastewater subjected to ultrafiltration, reverse osmosis, and ultraviolet disinfection) into the anaerobic Leederville aquifer in Perth, WA. Using culture-independent methods, this study showed the presence of Actinobacteria, Alphaproteobacteria, Bacilli, Betaproteobacteria, Cytophaga, Flavobacteria, Gammaproteobacteria, and Sphingobacteria, and a decrease in microbial diversity with an increase in depth of aquifer. Assessment of physico-chemical and microbiological properties of groundwater before and after recharge revealed that recharging the aquifer with aerobic recycled water resulted in elevated redox potentials in the aquifer and increased bacterial numbers, but reduced microbial diversity. The increase in bacterial numbers and reduced microbial diversity in groundwater could be a reflection of an increased denitrifier and sulfur-oxidizing populations in the aquifer, as a result of the increased availability of nitrate, oxygen, and residual organic matter. This is consistent with the geochemical data that showed pyrite oxidation and denitrification within the aquifer after recycled water recharge commenced. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Concentrate minimization and water recovery enhancement using pellet precipitator in a reverse osmosis process treating textile wastewater.

PubMed

Sahinkaya, Erkan; Sahin, Ahmet; Yurtsever, Adem; Kitis, Mehmet

2018-06-09

Industrial wastewater reuse together with zero or near zero liquid discharges have been a growing trend due to the requirement of sustainable water management mandated by water scarcity and tightening discharge regulations. Studies have been conducted on the reclamation of textile industry wastewater using RO processes. However a lot of scientific attention has been drawn upon limiting the amount of concentrate generated from RO processes, which depends on the concentrations of scale forming ions in the concentrate stream. Hence, this study aims at investigating the applicability of an ultra-filtration (UF) membrane integrated pellet reactor to remove scale forming ions, i.e. Ca 2+ , Mg 2+ and Si from the concentrate of a pilot-scale textile industry RO process, for the first time in the literature. The resulting effluent was further tested in a secondary RO process to decrease concentrate volume and increase total water recovery. The pellet reactor operated at an extremely low hydraulic retention time of 0.1 h removed scale forming ions, i.e. Ca 2+ , Mg 2+ , with 90-95% efficiency, which improved the secondary RO process performance up to 92-94% overall water recovery, i.e. near zero liquid discharge was reached. Ozonation of the concentrate partially removed COD and color, which further improved the secondary RO filtration performance. Copyright © 2018 Elsevier Ltd. All rights reserved.

Domestic applications for aerospace waste and water management technologies

NASA Technical Reports Server (NTRS)

Disanto, F.; Murray, R. W.

1972-01-01

Some of the aerospace developments in solid waste disposal and water purification, which are applicable to specific domestic problems are explored. Also provided is an overview of the management techniques used in defining the need, in utilizing the available tools, and in synthesizing a solution. Specifically, several water recovery processes will be compared for domestic applicability. Examples are filtration, distillation, catalytic oxidation, reverse osmosis, and electrodialysis. Solid disposal methods will be discussed, including chemical treatment, drying, incineration, and wet oxidation. The latest developments in reducing household water requirements and some concepts for reusing water will be outlined.

Saline solutions: the quest for fresh water.

PubMed Central

Reuther, C G

2000-01-01

Despite steady advances in the technology, desalination remains one of the most expensive ways to produce potable water. But as water scarcity forces communities to find new sources of drinking water, scientists are developing innovations that may soon make desalination a reasonable option for many more communities. The newest approach to desalination is membrane systems, which include reverse osmosis and electrodialysis systems. Current research seeks to make these systems more effective and less likely to produce environmentally hazardous by-products. Many facilities use traditional distillation to desalinate water, and efforts are being made to combine membranes and distillation for more efficient systems. PMID:10656867

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

NASA Astrophysics Data System (ADS)

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.

Strategies for merging microbial fuel cell technologies in water desalination processes: Start-up protocol and desalination efficiency assessment

NASA Astrophysics Data System (ADS)

Borjas, Zulema; Esteve-Núñez, Abraham; Ortiz, Juan Manuel

2017-07-01

Microbial Desalination Cells constitute an innovative technology where microbial fuel cell and electrodialysis merge in the same device for obtaining fresh water from saline water with no energy-associated cost for the user. In this work, an anodic biofilm of the electroactive bacteria Geobacter sulfurreducens was able to efficiently convert the acetate present in synthetic waste water into electric current (j = 0.32 mA cm-2) able to desalinate water. .Moreover, we implemented an efficient start-up protocol where desalination up to 90% occurred in a desalination cycle (water production:0.308 L m-2 h-1, initial salinity: 9 mS cm-1, final salinity: <1 mS cm-1) using a filter press-based MDC prototype without any energy supply (excluding peristaltic pump energy). This start-up protocol is not only optimized for time but also simplifies operational procedures making it a more feasible strategy for future scaling-up of MDCs either as a single process or as a pre-treatment method combined with other well established desalination technologies such as reverse osmosis (RO) or reverse electrodialysis.

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

PubMed

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.

Estimation of solar energy resources for low salinity water desalination in several regions of Russia

NASA Astrophysics Data System (ADS)

Tarasenko, A. B.; Kiseleva, S. V.; Shakun, V. P.; Gabderakhmanova, T. S.

2018-01-01

This paper focuses on estimation of demanded photovoltaic (PV) array areas and capital expenses to feed a reverse osmosis desalination unit (1 m3/day fresh water production rate). The investigation have been made for different climatic conditions of Russia using regional data on ground water salinity from different sources and empirical dependence of specific energy consumption on salinity and temperature. The most optimal results were obtained for Krasnodar, Volgograd, Crimea Republic and some other southern regions. Combination of salinity, temperature and solar radiation level there makes reverse osmosis coupled with photovoltaics very attractive to solve infrastructure problems in rural areas. Estimation results are represented as maps showing PV array areas and capital expenses for selected regions.

Molecular dynamics study of a polymeric reverse osmosis membrane.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harder, E.; Walters, D. E.; Bodnar, Y. D.

2009-07-30

Molecular dynamics (MD) simulations are used to investigate the properties of an atomic model of an aromatic polyamide reverse osmosis membrane. The monomers forming the polymeric membrane are cross-linked progressively on the basis of a heuristic distance criterion during MD simulations until the system interconnectivity reaches completion. Equilibrium MD simulations of the hydrated membrane are then used to determine the density and diffusivity of water within the membrane. Given a 3 MPa pressure differential and a 0.125 {micro}m width membrane, the simulated water flux is calculated to be 1.4 x 10{sup -6} m/s, which is in fair agreement with anmore » experimental flux measurement of 7.7 x 10{sup -6} m/s.« less

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

PubMed Central

2012-01-01

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%). PMID:23369431

Fouling characteristics of reverse osmosis membranes at different positions of a full-scale plant for municipal wastewater reclamation.

PubMed

Tang, Fang; Hu, Hong-Ying; Sun, Li-Juan; Sun, Ying-Xue; Shi, Na; Crittenden, John C

2016-03-01

Membrane fouling is an important shortcoming limiting the efficiency and wide application of reverse osmosis (RO) technology. In this paper, RO membranes in a full-scale municipal wastewater reclamation plant were autopsied. From the lead to tail position RO membranes in RO system, both of organic and inorganic matters on membranes reduced gradually. The higher ion products in RO concentrate didn't result in more serious inorganic scaling on the last position RO membranes, which was contrast with some other researches. Fe, Ca and Mg were major inorganic elements. Fe had a relatively low concentration in RO influent but the highest content on membranes. However, there was no specific pretreatment in terms of Fe removal. Ca and Mg scaling was controlled by the antiscalants injected. Organic fouling (75.0-84.5% of dry weights) was major problem on RO membranes due to the large amount of dissolved organic matters in secondary effluent as raw water. Hydrophilic acid (HIA, 48.0% of total DOC), hydrophobic acid (HOA, 23.6%) and hydrophobic neutral (HON, 19.0%) fraction was largest among the six fractions in RO influent, while HON (38.2-51.1%) and HOA (22.1-26.1%) tended to accumulate on membranes in higher quantities. Monitoring HON and HOA might help to forecast organic fouling. Copyright © 2015 Elsevier Ltd. All rights reserved.

21 CFR 177.2550 - Reverse osmosis membranes.

Code of Federal Regulations, 2014 CFR

2014-04-01

... maximum weight is 62 milligrams per square decimeter (4 milligrams per square inch) as a thin film... square decimeter (0.3 milligrams per square inch) as a thin film composite on a suitable support. The... square decimeter (0.03 milligrams per square inch). (3) For the purpose of this section, the reverse...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shamsuddin Ilias

Fouling problems are perhaps the single most important reason for relatively slow acceptance of ultrafiltration in many areas of chemical and biological processing. To overcome the losses in permeate flux associated with concentration polarization and fouling in cross flow membrane filtration, we investigated the concept of flow reversal as a method to enhance membrane flux in ultrafiltration. Conceptually, flow reversal prevents the formation of stable hydrodynamic and concentration boundary layers at or near the membrane surface. Further more, periodic reversal of the flow direction of the feed stream at the membrane surface results in prevention and mitigation of membrane fouling.more » Consequently, these advantages are expected to enhance membrane flux significantly. A crossflow membrane filtration unit was designed and built to test the concept of periodic flow reversal for flux enhancement. The essential elements of the system include a crossflow hollow fiber membrane module integrated with a two-way valve to direct the feed flow directions. The two-way valve is controlled by a controller-timer for periodic reversal of flow of feed stream. Another important feature of the system is that with changing feed flow direction, the permeate flow direction is also changed to maintain countercurrent feed and permeate flows for enhanced mass transfer driving force (concentration difference). In our previous report, we reported our work on UF of BSA. In this report, we report our continuing application of Flow Reversal technique in clarification of apple juice containing pectin. The presence of pectin in apple juice makes the clarification process difficult and is believed to cause membrane fouling. Of all compounds found in apple juice, pectin is most often identified as the major hindrance to filtration performance. Laboratory-scale tests on a hollow-fiber ultrafiltration membrane module using pectin in apple juice as feed show that under flow reversal conditions, the permeate flux is significantly enhanced when compared with the conventional unidirectional flow.« less

Polymer Coatings Reduce Electro-osmosis

NASA Technical Reports Server (NTRS)

Herren, Blair J.; Snyder, Robert; Shafer, Steven G.; Harris, J. Milton; Van Alstine, James M.

1989-01-01

Poly(ethylene glycol) film controls electrostatic potential. Electro-osmosis in quartz or glass chambers reduced or reversed by coating inside surface of chambers with monomacromolecular layers of poly(ethylene glycol). Stable over long times. Electrostatic potential across surface of untreated glass or plastic chamber used in electro-phoresis is negative and attracts cations in aqueous electrolyte. Cations solvated, entrains flow of electrolyte migrating toward cathode. Electro-osmotic flow interferes with desired electrophoresis of particles suspended in electrolyte. Polymer coats nontoxic, transparent, and neutral, advantageous for use in electrophoresis.

Development of Ultrafiltration Membrane-Separation Technology for Energy-Efficient Water Treatment and Desalination Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yim, Woosoon; Bae, Chulsung

The growing scarcity of fresh water is a major political and economic challenge in the 21st century. Compared to thermal-based distillation technique of water production, pressure driven membrane-based water purification process, such as ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO), can offer more energy-efficient and environmentally friendly solution to clean water production. Potential applications also include removal of hazardous chemicals (i.e., arsenic, pesticides, organics) from water. Although those membrane-separation technologies have been used to produce drinking water from seawater (desalination) and non-traditional water (i.e., municipal wastewater and brackish groundwater) over the last decades, they still have problems in ordermore » to be applied in large-scale operations. Currently, a major huddle of membrane-based water purification technology for large-scale commercialization is membrane fouling and its resulting increases in pressure and energy cost of filtration process. Membrane cleaning methods, which can restore the membrane properties to some degree, usually cause irreversible damage to the membranes. Considering that electricity for creating of pressure constitutes a majority of cost (~50%) in membrane-based water purification process, the development of new nano-porous membranes that are more resistant to degradation and less subject to fouling is highly desired. Styrene-ethylene/butylene-styrene (SEBS) block copolymer is one of the best known block copolymers that induces well defined morphologies. Due to the polarity difference of aromatic styrene unit and saturated ethylene/butylene unit, these two polymer chains self-assemble each other and form different phase-separated morphologies depending on the ratios of two polymer chain lengths. Because the surface of SEBS is hydrophobic which easily causes fouling of membrane, incorporation of ionic group (e,g, sulfonate) to the polymer is necessary to reduces fouling. Recently, sulfonated SEBS became commercially available and has been extensively explored for membrane-mediated water purification technology. The sulfonated block copolymer creates a well developed nano-sale phase-separated morphologies composed of hydrophilic domains (sulfonated polystyrene) and hydrophobic domains (polyethylene/polybutylene). The hydrophilic domains determines transport properties (water transport, salt and/or ion rejection, etc) and the hydrophobic domains provides mechanical stability of the membrane. Unfortunately, a high degree of sulfonation of SEBS induces excessive swelling and deterioration of mechanical stability of the membrane. In an effort to develop robust polymeric membrane materials for water purification technology, phosphonic acid-functionalized SEBS membranes are investigated during this report period. In compare to sulfonated polymers, the corresponding phosphonated polymers are known to swell less because of the formation of extensive hydrogen bonding networks between phosphonates. In addition to the expected better mechanical stability, phosphonated polymers has another advantage over sulfonated polymers for the use water purification membrane; each phosphonate can accommodate two ions while each sulfonate accommodates only one ion. Membrane properties (ion type, ionic density, etc) of new membranes will be studied and their separation performance will be evaluated in water purification and desalination process. Through systematic study of the relationship of chemical structure–surface property–membrane performance, we aim to better understand the nature of membrane fouling and develop more fouling-resistant water purification membranes. The basic understanding of this relationship will lead to the development of advanced membrane materials which can offer a solution to environmentally sustainable production of fresh water.« less

Performances of nanofiltration and low pressure reverse osmosis membranes for desalination: characterization and modelling

NASA Astrophysics Data System (ADS)

Boussouga, Y. A.; Lhassani, A.

2017-03-01

The nanofiltration and the reverse osmosis processes are the most common techniques for the desalination of water contaminated by an excess of salts. In this present study, we were interested in the characterization of commercial, composite and asymmetric membranes of nanofiltration (NF90, NF270) and low pressure reverse osmosis (BW30LE). The two types of characterization that we opted for our study: (i) characterization of electrical proprieties, in terms of the surface charge of various membranes studied by the measurement of the streaming potential, (ii) hydrodynamic characterization in terms of hydraulic permeability with pure water, mass transfer and phenomenological parameters for each system membrane/salt using hydrodynamic approaches. The irreversible thermodynamics allowed us to model the observed retention Robs of salts (NaCl and Na2SO4) for the different membranes studied, to understand and to predict a good filtration with a membrane. A study was conducted on the type of mass transfer for each system membrane/salt: convection and diffusion. The results showed that all tested membranes are negatively charged for the solutions at neutral pH, this is explained by their material composition. The results also showed competitiveness between the different types of membranes. In view of that the NF remains effective in terms of selective retention with less energy consumption than LPRO.

Renewable energy powered membrane technology. 1. Development and characterization of a photovoltaic hybrid membrane system.

PubMed

Schäfer, A I; Broeckmann, A; Richards, B S

2007-02-01

In isolated communities where potable water sources as well as energy grids are limited or nonexistent, treating brackish groundwater aquifers with small-scale desalination systems can be a viable alternative to existing water infrastructures. Given the unavailability of power in many such situations, renewable energy is an obvious solution to power such systems. However, renewable energy is an intermittent power supply and with regards to the performance of intermittently operated desalination systems, only very limited experience exists, both with regards to efficiency as well as water quality. In this paper, this lack of knowledge is addressed by evaluating a system operated with varying parameters (pressure and flow) with constant power as a step toward defining a safe operating window, and they provide a basis for interpreting future data obtained with a renewable energy source. Field trials were performed on a brackish (5300 mg/L TDS; 8290 microS/cm) bore in Central Australia with a photovoltaic-powered membrane filtration (PV-membrane) system. Four nanofiltration and reverse osmosis membranes (BW30, ESPA4, NF90, TFC-S) and a number of operation parameter combinations (transmembrane pressure, feed flow, TFC-S) and operating parameters transmembrane pressure and feed flow were investigated to find the best operating conditions for maximum drinking water production and minimum specific energy consumption (SEC). The ESPA4 membrane performed best for this brackish source, producing 250 L/h of excellent drinking water (257 mg/L TDS; 400 microS/ cm) at an SEC of 1.2 kWh/m3. The issue of brine disposal or reuse is also discussed and the article compares the salinity of the produced brine with livestock water. Since the feedwater is disinfected physically using ultrafiltration (UF), the brine is free from bacteria and most viruses and hence can be seen more as a reusable product stream than a waste stream with a disposal problem.

Molecular characterization of dissolved organic matter (DOM): a critical review.

PubMed

Nebbioso, Antonio; Piccolo, Alessandro

2013-01-01

Advances in water chemistry in the last decade have improved our knowledge about the genesis, composition, and structure of dissolved organic matter, and its effect on the environment. Improvements in analytical technology, for example Fourier-transform ion cyclotron (FT-ICR) mass spectrometry (MS), homo and hetero-correlated multidimensional nuclear magnetic resonance (NMR) spectroscopy, and excitation emission matrix fluorimetry (EEMF) with parallel factor (PARAFAC) analysis for UV-fluorescence spectroscopy have resulted in these advances. Improved purification methods, for example ultrafiltration and reverse osmosis, have enabled facile desalting and concentration of freshly collected DOM samples, thereby complementing the analytical process. Although its molecular weight (MW) remains undefined, DOM is described as a complex mixture of low-MW substances and larger-MW biomolecules, for example proteins, polysaccharides, and exocellular macromolecules. There is a general consensus that marine DOM originates from terrestrial and marine sources. A combination of diagenetic and microbial processes contributes to its origin, resulting in refractory organic matter which acts as carbon sink in the ocean. Ocean DOM is derived partially from humified products of plants decay dissolved in fresh water and transported to the ocean, and partially from proteinaceous and polysaccharide material from phytoplankton metabolism, which undergoes in-situ microbial processes, becoming refractory. Some of the DOM interacts with radiation and is, therefore, defined as chromophoric DOM (CDOM). CDOM is classified as terrestrial, marine, anthropogenic, or mixed, depending on its origin. Terrestrial CDOM reaches the oceans via estuaries, whereas autochthonous CDOM is formed in sea water by microbial activity; anthropogenic CDOM is a result of human activity. CDOM also affects the quality of water, by shielding it from solar radiation, and constitutes a carbon sink pool. Evidence in support of the hypothesis that part of marine DOM is of terrestrial origin, being the result of a long-term carbon sedimentation, has been obtained from several studies discussed herein.

THE CONTRIBUTIONS OF NORMAL AND ANOMALOUS OSMOSIS TO THE OSMOTIC EFFECTS ARISING ACROSS CHARGED MEMBRANES WITH SOLUTIONS OF ELECTROLYTES

PubMed Central

Grim, Eugene; Sollner, Karl

1957-01-01

The osmotic effect arising across a porous membrane separating the solution of an electrolyte from water (or a more dilute solution) is ordinarily due to both normal osmosis, as it occurs also with non-electrolytes, and to "anomalous" osmosis. It is shown that the normal osmotic component cannot be measured quantitatively by the conventional comparison with a non-electrolytic reference solute. Anomalous osmosis does not occur with electroneutral membranes. Accordingly, with membranes which can be charged and discharged reversibly (without changes in geometrical structure), such as many proteinized membranes, the osmotic effects caused by an electrolyte can be measured both when only normal osmosis arises (with the membrane in the electroneutral state) and when normal as well as anomalous osmosis occurs (with the membrane in a charged state). The difference between these two effects is the true anomalous osmosis. Data are presented on the osmotic effects across an oxyhemoglobin membrane in the uncharged state at pH 6.75 and in two charged states, positive at pH 4.0 and negative at pH 10.0, with solutions of a variety of electrolytes using a concentration ratio of 2:1 over a wide range of concentrations. The rates of the movement of liquid across the membrane against an inconsequentially small hydrostatic head are recorded instead of, as conventional, the physiologically less significant pressure rises after a standard time. PMID:13439166

Salinity Gradients for Sustainable Energy: Primer, Progress, and Prospects.

PubMed

Yip, Ngai Yin; Brogioli, Doriano; Hamelers, Hubertus V M; Nijmeijer, Kitty

2016-11-15

Combining two solutions of different composition releases the Gibbs free energy of mixing. By using engineered processes to control the mixing, chemical energy stored in salinity gradients can be harnessed for useful work. In this critical review, we present an overview of the current progress in salinity gradient power generation, discuss the prospects and challenges of the foremost technologies - pressure retarded osmosis (PRO), reverse electrodialysis (RED), and capacitive mixing (CapMix) and provide perspectives on the outlook of salinity gradient power generation. Momentous strides have been made in technical development of salinity gradient technologies and field demonstrations with natural and anthropogenic salinity gradients (for example, seawater-river water and desalination brine-wastewater, respectively), but fouling persists to be a pivotal operational challenge that can significantly ebb away cost-competitiveness. Natural hypersaline sources (e.g., hypersaline lakes and salt domes) can achieve greater concentration difference and, thus, offer opportunities to overcome some of the limitations inherent to seawater-river water. Technological advances needed to fully exploit the larger salinity gradients are identified. While seawater desalination brine is a seemingly attractive high salinity anthropogenic stream that is otherwise wasted, actual feasibility hinges on the appropriate pairing with a suitable low salinity stream. Engineered solutions are foulant-free and can be thermally regenerative for application in low-temperature heat utilization. Alternatively, PRO, RED, and CapMix can be coupled with their analog separation process (reverse osmosis, electrodialysis, and capacitive deionization, respectively) in salinity gradient flow batteries for energy storage in chemical potential of the engineered solutions. Rigorous techno-economic assessments can more clearly identify the prospects of low-grade heat conversion and large-scale energy storage. While research attention is squarely focused on efficiency and power improvements, efforts to mitigate fouling and lower membrane and electrode cost will be equally important to reduce levelized cost of salinity gradient energy production and, thus, boost PRO, RED, and CapMix power generation to be competitive with other renewable technologies. Cognizance of the recent key developments and technical progress on the different technological fronts can help steer the strategic advancement of salinity gradient as a sustainable energy source.

Water purification by reverse osmosis using heterocyclic polymer membranes

NASA Technical Reports Server (NTRS)

Scott, H.

1972-01-01

Pyrrone (polyimidazopyrrolone) polymers are a new class of thermally stable, radiation and chemical resistant aromatic-heterocyclic polymers featuring a greater chemical and mechanical durability than cellulose acetate.

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

PubMed

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

2017-09-01

Municipal wastewater treatment involves mechanical, biological and chemical treatment steps for protecting the environment from adverse effects. The biological treatment step consumes the most energy and can create greenhouse gases. This study investigates municipal wastewater treatment without the biological treatment step, including the effects of different pretreatment configurations, for example, direct membrane filtration before forward osmosis. Forward osmosis was tested using raw wastewater and wastewater subjected to different types of mechanical pretreatment, for example, microsieving and microfiltration permeation, as a potential technology for municipal wastewater treatment. Forward osmosis was performed using Aquaporin Inside™ and Hydration Technologies Inc. (HTI) membranes with NaCl as the draw solution. Both types of forward osmosis membranes were tested in parallel for the different types of pretreated feed and evaluated in terms of water flux and solute rejection, that is, biochemical oxygen demand (BOD 7 ) and total and soluble phosphorus contents. The Aquaporin and HTI membranes achieved a stable water flux with rejection rates of more than 96% for BOD 7 and total and soluble phosphorus, regardless of the type of mechanical pretreated wastewater considered. This result indicates that forward osmosis membranes can tolerate exposure to municipal waste water and that the permeate can fulfil the Swedish discharge limits.

Plasma polymerization of an ethylene-nitrogen gas mixture

NASA Technical Reports Server (NTRS)

Hudis, M.; Wydeven, T.

1975-01-01

A procedure has been developed whereby nitrogen can be incorporated into an organic film from an ethylene-nitrogen gas mixture using an internal electrode capacitively coupled radio frequency reactor. The presence of nitrogen has been shown directly by infrared transmittance spectra and electron spectroscopic chemical analysis data, and further indirect evidence was provided by dielectric measurements and by the reverse osmosis properties of the film. Preparation of a nitrogen containing film did not require vapor from an organic nitrogen containing liquid monomer. Some control over the bonding and stoichiometry of the polymer film was provided by the added degree of freedom of the nitrogen partial pressure in the gas mixture. This new parameter strongly affected the dielectric properties of the plasma polymerized film and could affect the reverse osmosis behavior.

Rotating Reverse Osmosis for Wastewater Reuse

NASA Technical Reports Server (NTRS)

Lueptow, Richard M.; Yoon, Yeomin; Pederson, Cynthia

2004-01-01

Our previous work established the concept of a low-pressure rotating reverse osmosis membrane system. The rotation of the cylindrical RO filter produces shear and Taylor vortices in the annulus of the device that decrease the concentration polarization and fouling commonly seen with conventional RO filtration techniques. A mathematical model based on the film theory and the solution-diffusion model agrees well with the experimental results obtained using this first generation prototype. However, based on the model, the filtrate flux and contaminant rejection depend strongly on the transmembrane pressure. Therefore, the goal of our current work is to improve the flux of the device by increasing the transmembrane pressure by a factor of 3 to 4. In addition, the rejections for a wider variety of inorganic and organic compounds typically found in space mission wastewater are measured.

Fouling mechanism in ultrafiltration of vegetable oil

NASA Astrophysics Data System (ADS)

Ariono, D.; Wardani, A. K.; Widodo, S.; Aryanti, Putu T. P.; Wenten, I. G.

2018-03-01

Energy efficient and cost-effective separation of impurities from vegetable oil is a great challenge for vegetable oil processing. Several technologies have been developed, including pressurized membrane, chemical treatment, and chemical free separation methods. Among those technologies, ultrafiltration membrane is one of the most attractive processes with low operating pressure and temperature. In this work, hydrophobic polypropylene ultrafiltration membrane was used to remove impurities such as non-dissolved solids from palm kernel oil. Unfortunately, the hydrophobicity of polypropylene membrane leads to significant impact on the reduction of permeate flux due to membrane fouling. This fouling is associated with the accumulation of substances on the membrane surface or within the membrane pores. For better understanding, fouling mechanism that occurred during palm kernel oil ultrafiltration using hydrophobic polypropylene membrane was investigated. The effect of trans-membrane pressure and feed temperature on fouling mechanism was also studied. The result showed that cake formation became the dominant fouling mechanism up to 50 min operation of palm kernel oil ultrafiltration. Furthermore, the fouling mechanism was not affected by the increase of trans-membrane pressure and feed temperature.

Performance evaluation of trimethylamine-carbon dioxide thermolytic draw solution for engineered osmosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boo, C; Khalil, YF; Elimelech, M

We evaluated the performance of trimethylamine-carbon dioxide (TMA-CO2) as a potential thermolytic draw solution for engineered osmosis. Water flux and reverse solute flux with TMA-CO2 draw solution were measured in forward osmosis (FO) and pressure retarded osmosis (PRO) modes using thin-film composite (TFC) and cellulose triacetate (CTA) FO membranes. Water flux with the TMA-CO2 draw solution was comparable to that obtained with the more common ammonia-carbon dioxide (NH3-CO2) thermolytic draw solution at similar (1 M) concentration. Using a TFC-FO membrane, the water fluxes produced by 1 M TMA-CO2 and NH3-CO2 draw solutions with a DI water feed were, respectively, 33.4more » and 35.6 L m(-2) h(-1) in PRO mode and 14.5 and 152 L m(-2) h(-1) in FO mode. Reverse draw permeation of TMA-CO2 was relatively low compared to NH3-CO2, ranging from 0.1 to 0.2 mol m(-2) h(-1) in all experiments, due to the larger molecular size of TMA. Thermal separation and recovery efficiency for TMA-CO2 was compared to NH3-CO2 by modeling low-temperature vacuum distillation utilizing low-grade heat sources. We also discuss possible challenges in the use TMA-CO2, including potential adverse impact on human health and environments. (C) 2014 Elsevier B.V. All rights reserved.« less

Hydraulic optimization and modeling of hydro-cyclone-systems for treatment and purification of any kind of waters

NASA Astrophysics Data System (ADS)

Spangemacher, Lars; Fröhlich, Siegmund; Buse, Hauke

2017-11-01

Water is an indispensable resource for many purposes and good drinking water quality is essential for mankind. This article is supposed to show the need for mobile water treatment systems and therefore to give an overview of different mobile drinking water systems and the technologies available for obtaining good water quality. The aim is to develop a simple to operate water treatment system with few processing stages such as multi-cyclone-cartridge and reverse osmosis with energy recuperation, while the focus is set on modeling and optimizing of hydrocyclone systems as the first treatment stage.

Nanostructured materials for water desalination.

PubMed

Humplik, T; Lee, J; O'Hern, S C; Fellman, B A; Baig, M A; Hassan, S F; Atieh, M A; Rahman, F; Laoui, T; Karnik, R; Wang, E N

2011-07-22

Desalination of seawater and brackish water is becoming an increasingly important means to address the scarcity of fresh water resources in the world. Decreasing the energy requirements and infrastructure costs of existing desalination technologies remains a challenge. By enabling the manipulation of matter and control of transport at nanometer length scales, the emergence of nanotechnology offers new opportunities to advance water desalination technologies. This review focuses on nanostructured materials that are directly involved in the separation of water from salt as opposed to mitigating issues such as fouling. We discuss separation mechanisms and novel transport phenomena in materials including zeolites, carbon nanotubes, and graphene with potential applications to reverse osmosis, capacitive deionization, and multi-stage flash, among others. Such nanostructured materials can potentially enable the development of next-generation desalination systems with increased efficiency and capacity.

Nanostructured materials for water desalination

NASA Astrophysics Data System (ADS)

Humplik, T.; Lee, J.; O'Hern, S. C.; Fellman, B. A.; Baig, M. A.; Hassan, S. F.; Atieh, M. A.; Rahman, F.; Laoui, T.; Karnik, R.; Wang, E. N.

2011-07-01

Desalination of seawater and brackish water is becoming an increasingly important means to address the scarcity of fresh water resources in the world. Decreasing the energy requirements and infrastructure costs of existing desalination technologies remains a challenge. By enabling the manipulation of matter and control of transport at nanometer length scales, the emergence of nanotechnology offers new opportunities to advance water desalination technologies. This review focuses on nanostructured materials that are directly involved in the separation of water from salt as opposed to mitigating issues such as fouling. We discuss separation mechanisms and novel transport phenomena in materials including zeolites, carbon nanotubes, and graphene with potential applications to reverse osmosis, capacitive deionization, and multi-stage flash, among others. Such nanostructured materials can potentially enable the development of next-generation desalination systems with increased efficiency and capacity.

True Anomalous Osmosis in Multi-Solute Model Membrane Systems

PubMed Central

Grim, Eugene; Sollner, Karl

1960-01-01

The transport of liquid across charged porous membranes separating two electrolytic solutions of different composition consists of both a normal and an anomalous osmotic component. Anomalous osmosis does not occur with electroneutral membranes. Thus, with membranes which can be charged and discharged reversibly, normal osmosis can be measured with the membrane in the electroneutral state, and normal together with anomalous osmosis with the membrane in a charged state, the difference between these two effects being the true anomalous osmosis. Data are presented on the osmotic effects across an oxyhemoglobin membrane in the uncharged state at pH 6.75 and in two charged states, positive at pH 4.0 and negative at pH 10.0, in multi-solute systems with 0.2 and 0.4 osmolar solutions of a variety of electrolytes and of glucose against solutions of other solutes of the same, one-half, and twice these osmolarities. In the simpler systems the magnitude of the true anomalous osmosis can be predicted semiquantitatively by reference to appropriate single-solute systems. In isoosmolar systems with two electrolytic solutions the anomalous osmotic flow rates may reach 300 µl./cm.2 hr. and more; systems with electrolytic solutions against solutions of glucose can produce twice this rate. These fluxes are of the same order of magnitude as the liquid transport rates across such living structures as the mucosa of dog gall bladder, ileum, and urinary bladder. PMID:13708691

Presidential Green Chemistry Challenge: 2011 Greener Reaction Conditions Award

EPA Pesticide Factsheets

Presidential Green Chemistry Challenge 2011 award winner, Kraton Performance Polymers, developed halogen-free, high-flow NEXAR polymer membranes using less solvent that save energy during reverse osmosis to desalinate water.

Safe drinking during cancer treatment

MedlinePlus

... words: Reverse osmosis filtration Distillation or distilled Water Filters Tap water should be safe when it comes ... small local well, even if you have a filter. Many sink filters, filters in refrigerators, pitchers that ...

Protein aggregation under high concentration/density state during chromatographic and ultrafiltration processes.

PubMed

Arakawa, Tsutomu; Ejima, Daisuke; Akuta, Teruo

2017-02-01

Local transient high protein concentration or high density condition can occur during processing of protein solutions. Typical examples are saturated binding of proteins during column chromatography and high protein concentration on the semi-permeable membrane during ultrafiltration. Both column chromatography and ultrafiltration are fundamental technologies, specially for production of pharmaceutical proteins. We summarize here our experiences related to such high concentration conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Water Walls for Life Support

NASA Technical Reports Server (NTRS)

Hammoudeh, Mona (Inventor); Flynn, Michael T. (Inventor); Gormly, Sherwin J. (Inventor); Richardson, Tra-My Justine (Inventor)

2017-01-01

A method and associated system for processing waste gases, liquids and solids, produced by human activity, to separate (i) liquids suitable for processing to produce potable water, (ii) solids and liquids suitable for construction of walls suitable for enclosing a habitat volume and for radiation shielding, and (iii) other fluids and solids that are not suitable for processing. A forward osmosis process and a reverse osmosis process are sequentially combined to reduce fouling and to permit accumulation of different processable substances. The invention may be used for long term life support of human activity.

Physical/chemical closed-loop water-recycling

NASA Technical Reports Server (NTRS)

Herrmann, Cal C.; Wydeven, Theodore

1991-01-01

Water needs, water sources, and means for recycling water are examined in terms appropriate to the water quality requirements of a small crew and spacecraft intended for long duration exploration missions. Inorganic, organic, and biological hazards are estimated for waste water sources. Sensitivities to these hazards for human uses are estimated. The water recycling processes considered are humidity condensation, carbon dioxide reduction, waste oxidation, distillation, reverse osmosis, pervaporation, electrodialysis, ion exchange, carbon sorption, and electrochemical oxidation. Limitations and applications of these processes are evaluated in terms of water quality objectives. Computerized simulation of some of these chemical processes is examined. Recommendations are made for development of new water recycling technology and improvement of existing technology for near term application to life support systems for humans in space. The technological developments are equally applicable to water needs on Earth, in regions where extensive water recycling is needed or where advanced water treatment is essential to meet EPA health standards.

Transport of trace organic compounds through novel forward osmosis membranes: Role of membrane properties and the draw solution.

PubMed

Sauchelli, Marc; Pellegrino, Giuseppe; D'Haese, Arnout; Rodríguez-Roda, Ignasi; Gernjak, Wolfgang

2018-05-05

Forward osmosis (FO) offers to be a very promising technology for the removal of trace organic compounds (TrOCs) from contaminated wastewater, and with the recent developments in FO membranes, the effect of both a higher water flux and reverse salt flux on the rejection of TrOCs needs to be explored. In this study two novel thin-film composite (TFC) membranes with greater water permeability and selectivity than the benchmark cellulose tri-acetate (CTA) membrane were compared at bench-scale in terms of TrOCs permeability. By probing the solute-membrane interactions that dictate the transport of TrOCs through the two membranes in the absence and presence of a draw solution, several conclusions were drawn. Firstly, steric hindrance is the main TrOCs transport -limiting mechanism through TFC membranes unless the negative membrane surface charge is significant, in which case, electrostatic interactions can dominate over steric hindrance. Secondly, the increase in ionic strength induced by the draw solution in the vicinity of and perhaps inside the membrane seems to favour the rejection of TrOCs by "shrinking" the membrane pores or by "shielding" the negative surface charge. Lastly, during FO operation, solute concentration polarisation becomes detrimental when working at high water fluxes, whereas the reverse solute flux has no direct impact on the transport of TrOCs through the membrane. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

PubMed

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.

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

Aljohani, Mohammed S.

2017-12-01

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

Gastrointestinal health effects associated with the consumption of drinking water produced by point-of-use domestic reverse-osmosis filtration units.

PubMed Central

Payment, P; Franco, E; Richardson, L; Siemiatycki, J

1991-01-01

During a prospective epidemiological study of gastrointestinal health effects associated with the consumption of drinking water produced by reverse-osmosis domestic units, a correlation was demonstrated between the bacterial counts on R2A medium incubated at 35 degrees C and the reported gastrointestinal symptoms in families who used these units. A univariate correlation was found with bacterial counts on R2A medium at 20 degrees C but was confounded by the bacterial counts at 35 degrees C. Other variables, such as family size and amount of water consumed, were not independently explanatory of the rate of illness. These observations raise concerns for the possibility of increased disease associated with certain point-of-use treatment devices for domestic use when high levels of bacterial growth occur. PMID:2059052

Poly/vinyl alcohol/ membranes for reverse osmosis

NASA Technical Reports Server (NTRS)

Katz, M. G.; Wydeven, T., Jr.

1981-01-01

A description is presented of the results of studies of the water and salt transport properties of PVA membranes, taking into account radiation crosslinked PVA membranes, diffusive salt permeability through PVA membranes, and heat treated PVA membranes. The experimental findings support an occurrence of independent water, and salt permeation processes. It is suggested that the salt permeation is governed by a solution-diffusion transport mechanism. The preparation of thin skinned, asymmetric PVA membranes is also discussed. The employed method has a certain similarity to the classical phase inversion method, which is widely applied in the casting of asymmetric reverse osmosis membranes. Instead of using a gelling bath composed of a nonsolvent for the membrane material and miscible with the solvent from which the membrane is cast, a 'complexing' bath is used, which is a solution of a complexing agent in water.

Promotion by humus-reducing bacteria for the degradation of UV254 absorbance in reverse-osmosis concentrates pretreated with O3-assisted UV-Fenton method.

PubMed

Xia, Jiaohui; Zhang, Hui; Ding, Shaoxuan; Li, Changyu; Ding, Jincheng; Lu, Jie

2017-07-12

The primary pollutants in reverse-osmosis concentrates (ROC) are the substances with the UV absorbance at 254 nm (UV 254 ), which is closely related to humic substances that can be degraded by humus-reducing bacteria. This work studied the degradation characteristics of humus-reducing bacteria in ROC treatment. The physiological and biochemical characteristics of humus-reducing bacteria were investigated, and the effects of pH values and electron donors on the reduction of humic analog, antraquinone-2, 6-disulfonate were explored to optimize the degradation. Furthermore, the O 3 -assisted UV-Fenton method was applied for the pretreatment of ROC, and the degradation of UV 254 absorbance was apparently promoted with their removal rate, reaching 84.2% after 10 days of degradation by humus-reducing bacteria.

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

PubMed

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.

Evaluation of the Sarex (trade name) 5-gpm oil-water separator, Type B. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Musa, G.D.

1986-06-01

This report covers an investigation conducted to evaluate the operational effectiveness of the Sarex 5 GPM Oil-Water Separator, Type B. The results of this study indicate that the Sarex 5 GPM Oil-Water Separator, Type B, is an effective method for the removal of crude oil from feedwater. The Sarex 5 GPM Oil-Water Separator Type B, could be operated under field conditions. An efficient and effective oil-water separator device is imperative in certain areas of the world where crude-oil contaminated feedwater is found. The presence of crude oil in the feedwater adversely affects the performance of the reverse osmosis water-purification unitsmore » (ROWPUs) used by the Army and Marines to purify fresh, brackish, and salt water. Both the 600 GPH ROWPU and the 150,000 GPD ROWPU use multi-media and cartridge filters for the removal of suspended solids from the feedwater before they enter the reverse-osmosis membranes. Removal of the crude oil, which affixes to the filters, is accomplished by a laborious cleaning process or by replacement of the filters. Crude oil or a derived soluble oil passing the filters and entering the reverse osmosis elements would result in decreased production rate, degradation of the membrane elements, and decreased quality of product water. Thus, satisfactory operation of the ROWPU in this scenario is dependent upon an efficient and effective oil-water separator device.« less

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

NASA Astrophysics Data System (ADS)

Vatanpour, Vahid; Zoqi, Naser

2017-02-01

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 highest fouling resistance.

A desalination battery.

PubMed

Pasta, Mauro; Wessells, Colin D; Cui, Yi; La Mantia, Fabio

2012-02-08

Water desalination is an important approach to provide fresh water around the world, although its high energy consumption, and thus high cost, call for new, efficient technology. Here, we demonstrate the novel concept of a "desalination battery", which operates by performing cycles in reverse on our previously reported mixing entropy battery. Rather than generating electricity from salinity differences, as in mixing entropy batteries, desalination batteries use an electrical energy input to extract sodium and chloride ions from seawater and to generate fresh water. The desalination battery is comprised by a Na(2-x)Mn(5)O(10) nanorod positive electrode and Ag/AgCl negative electrode. Here, we demonstrate an energy consumption of 0.29 Wh l(-1) for the removal of 25% salt using this novel desalination battery, which is promising when compared to reverse osmosis (~ 0.2 Wh l(-1)), the most efficient technique presently available. © 2012 American Chemical Society

The utilization of forward osmosis for coal tailings dewatering

EPA Science Inventory

The feasibility of dewatering coal tailings slurry by forward osmosis (FO) membrane process was investigated in this research. A prototype cell was designed and used for the dewatering tests. A cellulosic FO membrane (Hydration Technology Innovations, LLC, Albany, OR) was used fo...

Reclamation of the wastewater from an industrial park using hollow-fibre and spiral-wound membranes: 50 m3 d(-1) pilot testing and cost evaluation.

PubMed

Chu, C P; Jiaoa, S R; Hung, J M; Lu, C J; Chung, Y J

2009-08-01

The feasibility of reclaiming effluent from industrial park wastewater treatment plants through a membrane process was evaluated in three phases. In phase 1 we selected nine wastewater treatment plants (WWTPs), each with a design capacity exceeding 10,000 m3 d(-1), and analyzed the corresponding effluent composition. 'Potential recycling percentage', R, ranged from 50% to 80% for the industrial park WWTPs, indicating a high feasibility for the reuse of effluent. In phase 2, a 50 m3 d(-1) pilot plant was installed in one of the selected WWTPs and underwent testing for one year. The quality of the reclaimed water was suitable for general-purpose industrial use. In the two ultrafiltration (UF) modules tested, the hydrophilic polyethersulfone hollow-fibre module was more tolerant to variable properties, and had higher recycling percentages than those of backwashable hydrophobic polyvinylidene difluoride spiral-wound module. Using the spiral-wound UF module helped reduce the cost for producing 1 m3 of reclaimed water (US$0.80) compared with a hollow-fibre module (US$0.88). In phase 3, we evaluated the negative effects of refluxing the reverse osmosis retentate, containing high total dissolved solids and non-biodegradable organics, with the biological treatment unit of the upstream WWTP. Biological compactibility tests showed that the refluxed retentate ratio should be reduced to maintain the conductivity of mixed liquor in the aeration tank at less than 110% of the original value.

Removal of nonylphenol from industrial sludge by using an electron beam

NASA Astrophysics Data System (ADS)

Choi, Jang-Seung; Park, Jun-Hyun; Kim, Yuri; Kim, JinKyu; Jung, SeungTae; Han, Bumsoo; Alkhuraiji, Turki S.

2016-09-01

Endocrine disrupting chemicals (EDCs) and potential EDCs are mostly man-made, found in various materials such as pesticides, additives or contaminants in food, and personal care products. EDCs have been suspected to be associated with altered reproductive function in males and females increased incidence of breast cancer, abnormal growth patterns and neuro-developmental delays in children and changes in immune function. A number of processes were investigated regarding their potential for removing of endocrine disrupters. Those processes are ferric chloride coagulation, powdered activated carbon, magnetic ion exchange combined with microfiltration or ultrafiltration, as well as nanofiltration, and reverse osmosis. They show some good removal of EDCs in aqueous solution, but do not show good efficiency when EDCs are in sludge. High energy ionizing radiation has the ability to remove the EDCs with a very high degree of reliability and in a clean and efficient manner. The ionizing radiation interacts with EDCs both directly and indirectly. Direct interaction takes place with EDCs, and the structure of EDCs is destroyed or changed. During indirect interaction, radiolysis products of water result in the formation of highly reactive intermediates which then react with the target molecules, culminating in structural changes. For confirmation of radiation reduction of EDCs in industrial sludge, a pilot scale experiment up to 50 kGy of electron beam was conducted with samples from the textile dyeing industries. The experimental result showed over a 90% reduction of nonylphenol (NP) at absorbed doses of around 10 kGy.

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

PubMed

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.

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

PubMed

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.

Water hammer reduces fouling during natural water ultrafiltration.

PubMed

Broens, F; Menne, D; Pothof, I; Blankert, B; Roesink, H D W; Futselaar, H; Lammertink, R G H; Wessling, M

2012-03-15

Today's ultrafiltration processes use permeate flow reversal to remove fouling deposits on the feed side of ultrafiltration membranes. We report an as effective method: the opening and rapid closing of a valve on the permeate side of an ultrafiltration module. The sudden valve closure generates pressure fluctuations due to fluid inertia and is commonly known as "water hammer". Surface water was filtrated in hollow fiber ultrafiltration membranes with a small (5%) crossflow. Filtration experiments above sustainable flux levels (>125 l (m2h)(-1)) show that a periodic closure of a valve on the permeate side improves filtration performance as a consequence of reduced fouling. It was shown that this effect depends on flux and actuation frequency of the valve. The time period that the valve was closed proved to have no effect on filtration performance. The pressure fluctuations generated by the sudden stop in fluid motion due to the valve closure are responsible for the effect of fouling reduction. High frequency recording of the dynamic pressure evolution shows water hammer related pressure fluctuations to occur in the order of 0.1 bar. The pressure fluctuations were higher at higher fluxes (higher velocities) which is in agreement with the theory. They were also more effective at higher fluxes with respect to fouling mitigation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of transmembrane hydraulic pressure on performance of forward osmosis membranes.

PubMed

Coday, Bryan D; Heil, Dean M; Xu, Pei; Cath, Tzahi Y

2013-03-05

Forward osmosis (FO) is an emerging membrane separation process that continues to be tested and implemented in various industrial water and wastewater treatment applications. The growing interests in the technology have prompted laboratories and manufacturers to adopt standard testing methods to ensure accurate comparison of membrane performance under laboratory-controlled conditions; however, standardized methods might not capture specific operating conditions unique to industrial applications. Experiments with cellulose triacetate (CTA) and polyamide thin-film composite (TFC) FO membranes demonstrated that hydraulic transmembrane pressure (TMP), common in industrial operation of FO membrane elements, could affect membrane performance. Experiments were conducted with three FO membranes and with increasing TMP up to a maximum of 50 psi (3.45 bar). The feed solution was a mixture of salts and the draw solution was either a NaCl solution or concentrated seawater at similar osmotic pressure. Results revealed that TMP minimally affected water flux, reverse salt flux (RSF), and solute rejection of the CTA membrane. However, water flux through TFC membranes might slightly increase with increasing TMP, and RSF substantially declines with increasing TMP. It was observed that rejection of feed constituents was influenced by TMP and RSF.

Lead and Drinking Water from Private Wells

MedlinePlus

... Drinking Water Policy & Recommendations History of Drinking Water Treatment Drinking Water FAQ Fast Facts Healthy Water Sites Healthy Water ... if needed. You may also wish to consider water treatment methods such as reverse osmosis, distillation, and carbon ...

Two-step optimization of pressure and recovery of reverse osmosis desalination process.

PubMed

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.

Urea transport through composite polyallylamine membranes

NASA Technical Reports Server (NTRS)

Ballou, E. V.; Kubo, L. Y.; Spitze, L. A.; Wydeven, T.; Clark, J. A.

1977-01-01

Polyallylamine composite reverse osmosis membranes were prepared by plasma polymerization and deposition onto small-pored cellulose acetate/cellulose nitrate films. The polyallylamine coated the porous substrate with a thin uniform polymer film which exhibited water permeability and urea rejection, of interest because of the potential application of reverse osmosis to urine purification in closed environmental systems. The flux of C-14 labeled urea was studied under the influence of osmotic gradients provided by sodium chloride solutions. The urea flux was found to be enhanced by an osmotic pressure gradient in the same direction and diminished, but not prevented, by an opposing osmotic pressure gradient. Consideration is given to the mechanism of the urea transport, as well as to the influence of concentration polarization on the experimental results. The minimization of coupled flow in pores of a critical size range is apparently necessary to improve urea rejection.

Biological support media influence the bacterial biofouling community in reverse osmosis water reclamation demonstration plants.

PubMed

Ferrera, Isabel; Mas, Jordi; Taberna, Elisenda; Sanz, Joan; Sánchez, Olga

2015-01-01

The diversity of the bacterial community developed in different stages of two reverse osmosis (RO) water reclamation demonstration plants designed in a wastewater treatment plant (WWTP) in Tarragona (Spain) was characterized by applying 454-pyrosequencing of the 16S rRNA gene. The plants were fed by secondary treated effluent to a conventional pretreatment train prior to the two-pass RO system. Plants differed in the material used in the filtration process, which was sand in one demonstration plant and Scandinavian schists in the second plant. The results showed the presence of a highly diverse and complex community in the biofilms, mainly composed of members of the Betaproteobacteria and Bacteroidetes in all stages, with the presence of some typical wastewater bacteria, suggesting a feed water origin. Community similarities analyses revealed that samples clustered according to filter type, highlighting the critical influence of the biological supporting medium in biofilm community structure.

Cleaning efficacy of hydroxypropyl-beta-cyclodextrin for biofouling reduction on reverse osmosis membranes.

PubMed

Alayande, Abayomi Babatunde; Kim, Lan Hee; Kim, In S

2016-01-01

In this study, an environmentally friendly compound, hydroxypropyl-beta-cyclodextrin (HP-β-CD) was applied to clean reverse osmosis (RO) membranes fouled by microorganisms. The cleaning with HP-β-CD removed the biofilm and resulted in a flux recovery ratio (FRR) of 102%. As cleaning efficiency is sometimes difficult to determine using flux recovery data alone, attached bacterial cells and extracellular polymeric substances (EPS) were quantified after cleaning the biofouled membrane with HP-β-CD. Membrane surface characterization using scanning electron microscopy (SEM), attenuated total reflectance Fourier transform infrared (ATR-FTIR) and atomic force microscopy (AFM) confirmed the effectiveness of HP-β-CD in removal of biofilm from the RO membrane surface. Finally, a comparative study was performed to investigate the competitiveness of HP-β-CD with other known cleaning agents such as sodium dodecyl sulfate (SDS), ethylenediaminetetraacetic acid (EDTA), Tween 20, rhamnolipid, nisin, and surfactin. In all cases, HP-β-CD was superior.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cohen-Tanugi, David; Grossman, Jeffrey C.

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 permeabilitymore » 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}.« less

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

PubMed Central

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

Nanofiltration/reverse osmosis for treatment of coproduced waters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mondal, S.; Hsiao, C.L.; Wickramasinghe, S.R.

2008-07-15

Current high oil and gas prices have lead to renewed interest in exploration of nonconventional energy sources such as coal bed methane, tar sand, and oil shale. However oil and gas production from these nonconventional sources has lead to the coproduction of large quantities of produced water. While produced water is a waste product from oil and gas exploration it is a very valuable natural resource in the arid Western United States. Thus treated produced water could be a valuable new source of water. Commercially available nanofiltration and low pressure reverse osmosis membranes have been used to treat three producedmore » waters. The results obtained here indicate that the permeate could be put to beneficial uses such as crop and livestock watering. However minimizing membrane fouling will be essential for the development of a practical process. Field Emission Scanning Electron Microscopy imaging may be used to observe membrane fouling.« less

Evaluation of membrane bioreactor for advanced treatment of industrial wastewater and reverse osmosis pretreatment

PubMed Central

2013-01-01

The evaluation of a membrane bioreactor (MBR) for pretreatment of reverse osmosis (RO) in order to reuse and reclamation of industrial town wastewater treatment plant was investigated in this study. Performance of MBR effluent through water quality in term of parameters such as chemical oxygen demand (COD), total suspended solids (TSS), total nitrogen (TN) and total coliform (TC) were measured. Also Silt density index (SDI) was used as indicator for RO feed water. The results of this study demonstrated that MBR produce a high quality permeate water. Approximately 75%, 98%, 74% and 99.9% removal of COD, TSS, TN and TC were recorded, respectively. Also SDI of the permeate effluent from membrane was below 3 for most of the times. It means that pilot yield a high quality treated effluent from the membrane module which can be used as RO feed water. PMID:24355199

Methylated liquor treatment process in caffeine production

NASA Astrophysics Data System (ADS)

Zhou, Junbo; Yang, Mingyang; Huang, Wenjia; Cui, Shenglu; Gao, Liping

2018-02-01

The caffeine production process produces a large amount of sodium methyl sulphate in the methylated mother liquor. In order to recycle this part of ingredient, we use the mother liquid of Shijiazhuang Xin Nuowei Pharmaceutical Co., Ltd. as the object of study, the use of “nanofiltration (NF) - Dish Type Reverse Osmosis (DTRO) “combination of membrane technology for desalination and concentration. The experimental results show that the concentration of sodium sulfate in the nanofiltration solution is 0.37 g • L -1, the rejection rate is 98%, and the concentration of sodium methyl sulfate in DTRO concentrated solution is 453.80 g • L -1, which meets the requirements of the enterprise.

Functional membranes. Present and future

NASA Technical Reports Server (NTRS)

Kunitake, T.

1982-01-01

The present situation and the future development of the functional membrane are discussed. It is expected that functional membranes will play increasingly greater roles in the chemical industry of the coming decade. These membranes are formed from polymer films, liquid membranes or bilayer membranes. The two most important technologies based on the polymeric membrane are reverse osmosis and ion exchange. The liquid membrane is used for separation of ionic species; an extension of the solvent extraction process. By using appropriate ligands and ionophores, highly selective separations are realized. The active transport is made possible if the physical and chemical potentials are applied to the transport process. More advanced functional membranes may be designed on the basis of the synthetic bilayer membrane.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 basedmore » 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 optimization of membranes is recommended. The identification of optimal osmotic agents for different applications is also suggested as it is clear that the space of potential agents and recovery processes has not been fully explored.« less

Selection of forward osmosis draw solutes for subsequent integration with anaerobic treatment to facilitate resource recovery from wastewater.

PubMed

Ansari, Ashley J; Hai, Faisal I; Guo, Wenshan; Ngo, Hao H; Price, William E; Nghiem, Long D

2015-09-01

Forward osmosis (FO) can be used to extract clean water and pre-concentrate municipal wastewater to make it amenable to anaerobic treatment. A protocol was developed to assess the suitability of FO draw solutes for pre-concentrating wastewater for potential integration with anaerobic treatment to facilitate resource recovery from wastewater. Draw solutes were evaluated in terms of their ability to induce osmotic pressure, water flux, and reverse solute flux. The compatibility of each draw solute with subsequent anaerobic treatment was assessed by biomethane potential analysis. The effect of each draw solute (at concentrations corresponding to the reverse solute flux at ten-fold pre-concentration of wastewater) on methane production was also evaluated. The results show that ionic organic draw solutes (e.g., sodium acetate) were most suitable for FO application and subsequent anaerobic treatment. On the other hand, the reverse solute flux of inorganic draw solutions could inhibit methane production from FO pre-concentrated wastewater. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

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

PubMed

Kalafatakis, S; Braekevelt, S; Lymperatou, A; Zarebska, A; Hélix-Nielsen, C; Lange, L; Skiadas, I V; Gavala, H N

2018-04-24

Forward osmosis (FO) is a low energy-intensive process since the driving force for water transport is the osmotic pressure difference, Δπ, between the feed and draw solutions, separated by the FO membrane, where π draw  > π feed . The potential of FO in wastewater treatment and desalination have been 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 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 financial benefits, although the integrated FO-fermentation process demonstrated lower water flux than expected. FTIR analyses of the membrane surface implied that the decrease in water flux was due to the presence of proteins, polysaccharides and other extracellular polymeric substances on the membrane active layer, indicating the presence of a fouling layer. Based on these findings, possible fouling alleviation strategies and future research directions are discussed and proposed.

Forward osmosis niches in seawater desalination and wastewater reuse.

PubMed

Valladares Linares, R; Li, Z; Sarp, S; Bucs, Sz S; Amy, G; Vrouwenvelder, J S

2014-12-01

This review focuses on the present status of forward osmosis (FO) niches in two main areas: seawater desalination and wastewater reuse. Specific applications for desalination and impaired-quality water treatment and reuse are described, as well as the benefits, advantages, challenges, costs and knowledge gaps on FO hybrid systems are discussed. FO can play a role as a bridge to integrate upstream and downstream water treatment processes, to reduce the energy consumption of the entire desalination or water recovery and reuse processes, thus achieving a sustainable solution for the water-energy nexus. FO hybrid membrane systems showed to have advantages over traditional membrane process like high pressure reverse osmosis and nanofiltration for desalination and wastewater treatment: (i) chemical storage and feed water systems may be reduced for capital, operational and maintenance cost, (ii) water quality is improved, (iii) reduced process piping costs, (iv) more flexible treatment units, and (v) higher overall sustainability of the desalination and wastewater treatment process. Nevertheless, major challenges make FO systems not yet a commercially viable technology, the most critical being the development of a high flux membrane, capable of maintaining an elevated salt rejection and a reduced internal concentration polarization effect, and the availability of appropriate draw solutions (cost effective and non-toxic), which can be recirculated via an efficient recovery process. This review article highlights the features of hybrid FO systems and specifically provides the state-of-the-art applications in the water industry in a novel classification and based on the latest developments toward scaling up these systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

Energy requirements of the switchable polarity solvent forward osmosis (SPS-FO) water purification process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wendt, Daniel S.; Orme, Christopher J.; Mines, Gregory L.

A model was developed to estimate the process energy requirements of a switchable polarity solvent forward osmosis (SPS FO) system for water purification from aqueous NaCl feed solution concentrations ranging from 0.5 to 4.0 molal at an operational scale of 480 m3/day (feed stream). The model indicates recovering approximately 90% of the water from a feed solution with NaCl concentration similar to seawater using SPS FO would have total equivalent energy requirements between 2.4 and 4.3 kWh per m 3 of purified water product. The process is predicted to be competitive with current costs for disposal/treatment of produced water frommore » oil and gas drilling operations. As a result, once scaled up the SPS FO process may be a thermally driven desalination process that can compete with the cost of seawater reverse osmosis.« less

Energy requirements of the switchable polarity solvent forward osmosis (SPS-FO) water purification process

DOE PAGES

Wendt, Daniel S.; Orme, Christopher J.; Mines, Gregory L.; ...

2015-08-01

A model was developed to estimate the process energy requirements of a switchable polarity solvent forward osmosis (SPS FO) system for water purification from aqueous NaCl feed solution concentrations ranging from 0.5 to 4.0 molal at an operational scale of 480 m3/day (feed stream). The model indicates recovering approximately 90% of the water from a feed solution with NaCl concentration similar to seawater using SPS FO would have total equivalent energy requirements between 2.4 and 4.3 kWh per m 3 of purified water product. The process is predicted to be competitive with current costs for disposal/treatment of produced water frommore » oil and gas drilling operations. As a result, once scaled up the SPS FO process may be a thermally driven desalination process that can compete with the cost of seawater reverse osmosis.« less

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

PubMed

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 <5 kDa. However, the post-GAC adsorption column (with filtration velocity of 5.7 m/h, breakthrough point adsorption capacity of 0.22 mg DOC/g GAC) exhibited excellent removal efficiency on the dominant DOM fraction of MW <5 kDa in the ROC. The removal efficiency of DOC, UV254, and TDS in the ROC was up to 91.8, 96, and 76.5 %, respectively, by the FeCl3 coagulation and post-GAC adsorption. Also, the DOM with both genotoxicity and antiestrogenic 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.

Flexographic newspaper deinking : treatment of wash filtrate effluent by membrane technology

Treesearch

B. Chabot; G.A. Krishnagopalan; S. Abubakr

1999-01-01

Ultrafiltration was investigated as a means to remove flexographic ink pigments from wash filtrate effluent generated from various mixtures of flexographic and offset old newspapers from deinking operations. Membrane separation efficiency was assessed from permeate flux, fouling rate, and ease of membrane regeneration (cleaning). Ultrafiltration was capable of...

Interplay of different NOM fouling mechanisms during ultrafiltration for drinking water production.

PubMed

Jermann, D; Pronk, W; Meylan, S; Boller, M

2007-04-01

Ultrafiltration is an emerging technology for drinking water production, but a main challenge remains the lack of understanding about fouling. This paper investigates the impact of molecular interactions between different natural organic matter (NOM) compounds on ultrafiltration fouling mechanisms. We performed dead-end filtration experiments with individual and mixed humic acid and alginate (polysaccharide). Alginate showed detrimental, but mostly reversible, flux decline and high solute retention. Our results indicate that this was caused by pore blocking transformed into cake building and weak molecular foulant-membrane and foulant-foulant interactions. In the presence of calcium, aggravated fouling was observed, related to complexation of alginate and its subsequently induced gel formation. With humic acid, more severe irreversible fouling occurred due to humic acid adsorption. Minor adsorption of alginate onto the membrane was also observed, which probably caused the substantial irreversible flux decline. The fouling characteristics in the mixtures reflected a combination of the individual humic acid and alginate experiments and we conclude, that the individual fouling mechanisms mutually influence each other. A model elucidates this interplay of the individual fouling mechanisms via hydrophobic and electrostatic interactions. In our study such an interplay resulted in an alginate cake, or gel in the presence of calcium, which is relatively irreversibly adsorbed onto the membrane by humic acid associations. This study shows the importance of mutual influences between various foulants for improved understanding of fouling phenomena. Furthermore it shows that substances with a minor individual influence might have a large impact in mixed systems such as natural water.

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

PubMed

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.

Surface modification of polyamide reverse osmosis membrane with organic-inorganic hybrid material for antifouling

NASA Astrophysics Data System (ADS)

Zhang, Yang; Wan, Ying; Pan, Guoyuan; Yan, Hao; Yao, Xuerong; Shi, Hongwei; Tang, Yujing; Wei, Xiangrong; Liu, Yiqun

2018-03-01

A series of thin-film composite reverse osmosis membranes based on polyamide have been modified by coating the polyvinyl alcohol and 3-mercaptopropyltriethoxysilane aqueous solution prepared by a sol-gel process on the membrane surface, followed by thermal crosslinking treatment. In order to improve the hydrophilicity of the modified TFC membranes, the membranes were then immersed into H2O2 aqueous solution to convert -SH into -SO3H. The resulting TFC membranes were characterized by SEM, AFM, ATR-FTIR, streaming potential, XPS as well as static contact angle. After surface modification with the organic-inorganic hybrid material, the TFC membranes show increased NaCl rejection and decreased water flux with increasing 3-mercaptopropyltrimethoxysilane content in coating solution. The optimal modification membrane (PA-SMPTES-0.8) exhibits a NaCl rejection of 99.29%, higher than that (97.20%) of the virgin PA membrane, and a comparable water flux to virgin PA membrane (41.7 L/m2 h vs 47.9 L/m2 h). More importantly, PA-SMPTES-0.8 membrane shows much more improved fouling resistance to BSA than virgin PA and PVA modified PA (PA-PVA-1.0) membranes. PA-SMPTES-0.8 membrane loses about 13% of the initial flux after BSA fouling for 12 h, which is lower than that of virgin PA and PA-PVA-1.0 membranes (42% and 18%). Furthermore, the flux recovery of PA-SMPTES-0.8 membrane reaches 94% after cleaning. Thus the TFC membranes modified by this organic-inorganic hybrid technology show potential applications as antifouling RO membrane for desalination and purification.

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).

PubMed

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

2016-03-15

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

SPREADSHEET BASED SCALING CALCULATIONS AND MEMBRANE PERFORMANCE

EPA Science Inventory

Many membrane element manufacturers provide a computer program to aid buyers in the use of their elements. However, to date there are few examples of fully integrated public domain software available for calculating reverse osmosis and nanofiltration system performance. The Total...

Continuous countercurrent membrane column for the separation of solute/solvent and solvent/solvent systems

DOEpatents

Nerad, Bruce A.; Krantz, William B.

1988-01-01

A reverse osmosis membrane process or hybrid membrane - complementary separator process for producing enriched product or waste streams from concentrated and dilute feed streams for both solvent/solvent and solute/solvent systems is described.

Electroplating and Cyanide Waste.

ERIC Educational Resources Information Center

Torpy, Michael F.; Runke, Henry M.

1978-01-01

Presents a literature review of wastes from electroplating industry, covering publications of 1977. This review covers studies such as: (1) ion exchange treatment process; (2) use of reverse osmosis; and (3) cyanide removal and detection. A list of 75 references is also presented. (HM)

The A-B-C of Desalting.

ERIC Educational Resources Information Center

Department of the Interior, Washington, DC. Office of Water Research and Technology.

This publication provides a simple explanation of how various processes convert sea or brackish water to fresh water. Included are descriptions of the membrane processes (reverse osmosis, electrodialysis, transport depletion, and piezodialysis); the distillation processes (multistage flash distillation, vertical tube distillation, multieffect…

Role of Reverse Divalent Cation Diffusion in Forward Osmosis Biofouling.

PubMed

Xie, Ming; Bar-Zeev, Edo; Hashmi, Sara M; Nghiem, Long D; Elimelech, Menachem

2015-11-17

We investigated the role of reverse divalent cation diffusion in forward osmosis (FO) biofouling. FO biofouling by Pseudomonas aeruginosa was simulated using pristine and chlorine-treated thin-film composite polyamide membranes with either MgCl2 or CaCl2 draw solution. We related FO biofouling behavior-water flux decline, biofilm architecture, and biofilm composition-to reverse cation diffusion. Experimental results demonstrated that reverse calcium diffusion led to significantly more severe water flux decline in comparison with reverse magnesium permeation. Unlike magnesium, reverse calcium permeation dramatically altered the biofilm architecture and composition, where extracellular polymeric substances (EPS) formed a thicker, denser, and more stable biofilm. We propose that FO biofouling was enhanced by complexation of calcium ions to bacterial EPS. This hypothesis was confirmed by dynamic and static light scattering measurements using extracted bacterial EPS with the addition of either MgCl2 or CaCl2 solution. We observed a dramatic increase in the hydrodynamic radius of bacterial EPS with the addition of CaCl2, but no change was observed after addition of MgCl2. Static light scattering revealed that the radius of gyration of bacterial EPS with addition of CaCl2 was 20 times larger than that with the addition of MgCl2. These observations were further confirmed by transmission electron microscopy imaging, where bacterial EPS in the presence of calcium ions was globular, while that with magnesium ions was rod-shaped.

Comparison of energy efficiency and power density in pressure retarded osmosis and reverse electrodialysis.

PubMed

Yip, Ngai Yin; Elimelech, Menachem

2014-09-16

Pressure retarded osmosis (PRO) and reverse electrodialysis (RED) are emerging membrane-based technologies that can convert chemical energy in salinity gradients to useful work. The two processes have intrinsically different working principles: controlled mixing in PRO is achieved by water permeation across salt-rejecting membranes, whereas RED is driven by ion flux across charged membranes. This study compares the energy efficiency and power density performance of PRO and RED with simulated technologically available membranes for natural, anthropogenic, and engineered salinity gradients (seawater-river water, desalination brine-wastewater, and synthetic hypersaline solutions, respectively). The analysis shows that PRO can achieve both greater efficiencies (54-56%) and higher power densities (2.4-38 W/m(2)) than RED (18-38% and 0.77-1.2 W/m(2)). The superior efficiency is attributed to the ability of PRO membranes to more effectively utilize the salinity difference to drive water permeation and better suppress the detrimental leakage of salts. On the other hand, the low conductivity of currently available ion exchange membranes impedes RED ion flux and, thus, constrains the power density. Both technologies exhibit a trade-off between efficiency and power density: employing more permeable but less selective membranes can enhance the power density, but undesired entropy production due to uncontrolled mixing increases and some efficiency is sacrificed. When the concentration difference is increased (i.e., natural → anthropogenic → engineered salinity gradients), PRO osmotic pressure difference rises proportionally but not so for RED Nernst potential, which has logarithmic dependence on the solution concentration. Because of this inherently different characteristic, RED is unable to take advantage of larger salinity gradients, whereas PRO power density is considerably enhanced. Additionally, high solution concentrations suppress the Donnan exclusion effect of the charged RED membranes, severely reducing the permselectivity and diminishing the energy conversion efficiency. This study indicates that PRO is more suitable to extract energy from a range of salinity gradients, while significant advancements in ion exchange membranes are likely necessary for RED to be competitive with PRO.

Comparison of Energy Efficiency and Power Density in Pressure Retarded Osmosis and Reverse Electrodialysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yip, NY; Elimelech, M

Pressure retarded osmosis (PRO) and reverse electrodialysis (RED) are emerging membrane-based technologies that can convert chemical energy in salinity gradients to useful work. The two processes have intrinsically different working principles: controlled mixing in PRO is achieved by water permeation across salt-rejecting membranes, whereas RED is driven by ion flux across charged membranes. This study compares the energy efficiency and power density performance of PRO and RED with simulated technologically available membranes for natural, anthropogenic, and engineered salinity gradients (seawater-river water, desalination brine-wastewater, and synthetic hypersaline solutions, respectively). The analysis shows that PRO can achieve both greater efficiencies (54-56%) andmore » higher power densities (2.4-38 W/m(2)) than RED (18-38% and 0.77-1.2 W/m(2)). The superior efficiency is attributed to the ability of PRO membranes to more effectively utilize the salinity difference to drive water permeation and better suppress the detrimental leakage of salts. On the other hand, the low conductivity of currently available ion exchange membranes impedes RED ion flux and, thus, constrains the power density. Both technologies exhibit a trade-off between efficiency and power density: employing more permeable but less selective membranes can enhance the power density, but undesired entropy production due to uncontrolled mixing increases and some efficiency is sacrificed. When the concentration difference is increased (i.e., natural -> anthropogenic -> engineered salinity gradients), PRO osmotic pressure difference rises proportionally but not so for RED Nernst potential, which has logarithmic dependence on the solution concentration. Because of this inherently different characteristic, RED is unable to take advantage of larger salinity gradients, whereas PRO power density is considerably enhanced. Additionally, high solution concentrations suppress the Donnan exclusion effect of the charged RED membranes, severely reducing the permselectivity and diminishing the energy conversion efficiency. This study indicates that PRO is more suitable to extract energy from a range of salinity gradients, while significant advancements in ion exchange membranes are likely necessary for RED to be competitive with PRO.« less

Research on the experiment of reservoir water treatment applying ultrafiltration membrane technology of different processes.

PubMed

Zhang, Liyong; Zhang, Penghui; Wang, Meng; Yang, Kai; Liu, Junliang

2016-09-01

The processes and effects of coagulation-ultrafiltration (C-UF) and coagulation sedimentation-ultrafiltration (CS-UF) process used in the treatment of Dalangdian Reservoir water were compared. The experiment data indicated that 99% of turbidity removal and basically 100% of microorganism and algae removal were achieved in both C-UF and CS-UF process. The organic removal effect of CS-UF? process was slightly better than C-UF process. However, the organic removal effect under different processes was not obvious due to limitation of ultrafiltration membrane aperture. Polyaluminium chloride was taken as a coagulant in water plant. The aluminum ion removal result revealed that coagulant dosage was effectively saved by using membrane technology during megathermal high algae laden period. Within the range of certain reagent concentration and soaking time, air-water backwashing of every filtration cycle of membrane was conducted to effectively reduce membrane pollution. Besides, maintenance cleaning was conducted every 60 min. whether or not restorative cleaning was conducted depends on the pollution extent. After cleaning, recovery of membrane filtration effect was obvious.

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

NASA Astrophysics Data System (ADS)

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.

Possible treatments for arsenic removal in Latin American waters for human consumption.

PubMed

Litter, Marta I; Morgada, Maria E; Bundschuh, Jochen

2010-05-01

Considering the toxic effects of arsenic, the World Health Organization recommends a maximum concentration of 10 microg L(-1) of arsenic in drinking water. Latin American populations present severe health problems due to consumption of waters with high arsenic contents. The physicochemical properties of surface and groundwaters are different from those of other more studied regions of the planet, and the problem is still publicly unknown. Methods for arsenic removal suitable to be applied in Latin American waters are here summarized and commented. Conventional technologies (oxidation, coagulation-coprecipitation, adsorption, reverse osmosis, use of ion exchangers) are described, but emphasis is made in emergent decentralized economical methods as the use of inexpensive natural adsorbents, solar light technologies or biological treatments, as essential to palliate the situation in poor, isolated and dispersed populations of Latin American regions. Copyright 2010 Elsevier Ltd. All rights reserved.

Bioremoval of heavy metals by bacterial biomass.

PubMed

Aryal, Mahendra; Liakopoulou-Kyriakides, Maria

2015-01-01

Heavy metals are among the most common pollutants found in the environment. Health problems due to the heavy metal pollution become a major concern throughout the world, and therefore, various treatment technologies such as reverse osmosis, ion exchange, solvent extraction, chemical precipitation, and adsorption are adopted to reduce or eliminate their concentration in the environment. Biosorption is a cost-effective and environmental friendly technique, and it can be used for detoxification of heavy metals in industrial effluents as an alternative treatment technology. Biosorption characteristics of various bacterial species are reviewed here with respect to the results reported so far. The role of physical, chemical, and biological modification of bacterial cells for heavy metal removal is presented. The paper evaluates the different kinetic, equilibrium, and thermodynamic models used in bacterial sorption of heavy metals. Biomass characterization and sorption mechanisms as well as elution of metal ions and regeneration of biomass are also discussed.

Physical/chemical closed-loop water-recycling for long-duration missions

NASA Technical Reports Server (NTRS)

Herrmann, Cal C.; Wydeven, Ted

1990-01-01

Water needs, water sources, and means for recycling water are examined in terms appropriate to the water quality requirements of a small crew and spacecraft intended for long duration exploration missions. Inorganic, organic, and biological hazards are estimated for waste water sources. Sensitivities to these hazards for human uses are estimated. The water recycling processes considered are humidity condensation, carbon dioxide reduction, waste oxidation, distillation, reverse osmosis, pervaporation, electrodialysis, ion exchange, carbon sorption, and electrochemical oxidation. Limitations and applications of these processes are evaluated in terms of water quality objectives. Computerized simulation of some of these chemical processes is examined. Recommendations are made for development of new water recycling technology and improvement of existing technology for near term application to life support systems for humans in space. The technological developments are equally applicable to water needs on earth, in regions where extensive water ecycling is needed or where advanced water treatment is essential to meet EPA health standards.

Impact of ozonation, anion exchange resin and UV/H2O2 pre-treatments to control fouling of ultrafiltration membrane for drinking water treatment.

PubMed

Pramanik, Biplob Kumar; Pramanik, Sagor Kumar; Sarker, Dipok Chandra; Suja, Fatihah

2017-06-01

The effects of ozonation, anion exchange resin (AER) and UV/H 2 O 2 were investigated as a pre-treatment to control organic fouling (OF) of ultrafiltration membrane in the treatment of drinking water. It was found that high molecular weight (MW) organics such as protein and polysaccharide substances were majorly responsible for reversible fouling which contributed to 90% of total fouling. The decline rate increased with successive filtration cycles due to deposition of protein content over time. All pre-treatment could reduce the foulants of a Ultrafiltration membrane which contributed to the improvement in flux, and there was a greater improvement of flux by UV/H 2 O 2 (61%) than ozonation (43%) which in turn was greater than AER (23%) treatment. This was likely due to the effective removal/breakdown of high MW organic content. AER gave greater removal of biofouling potential components (such as biodegradable dissolved organic carbon and assimilable organic carbon contents) compared to UV/H 2 O 2 and ozonation treatment. Overall, this study demonstrated the potential of pre-treatments for reducing OF of ultrafiltration for the treatment of drinking water.

Lyophilization and Reconstitution of Reverse Osmosis Concentrated Natural Organic Matter

EPA Science Inventory

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

Overlap among Environmental Databases.

ERIC Educational Resources Information Center

Miller, Betty

1981-01-01

Describes the methodology and results of a study comparing the overlap of Enviroline, Pollution, and the Environmental Periodicals Bibliography files through searches on acid rain, asbestos and water, diesel, glass recycling, Lake Erie, Concorde, reverse osmosis wastewater treatment cost, and Calspan. Nine tables are provided. (RBF)

Lyophilization, Reconstitution, and DBP Formation in Reverse-Osmosis Concentrated Natural Organic Matter

EPA Science Inventory

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 w...

Design for waste-management system

NASA Technical Reports Server (NTRS)

Guarneri, C. A.; Reed, A.; Renman, R.

1973-01-01

Study was made and system defined for water-recovery and solid-waste processing for low-rise apartment complexes. System can be modified to conform with unique requirements of community, including hydrology, geology, and climate. Reclamation is accomplished by treatment process that features reverse-osmosis membranes.

Reducing uncertainty in estimating virus reduction by advanced water treatment processes.

PubMed

Gerba, Charles P; Betancourt, Walter Q; Kitajima, Masaaki; Rock, Channah M

2018-04-15

Treatment of wastewater for potable reuse requires the reduction of enteric viruses to levels that pose no significant risk to human health. Advanced water treatment trains (e.g., chemical clarification, reverse osmosis, ultrafiltration, advanced oxidation) have been developed to provide reductions of viruses to differing levels of regulatory control depending upon the levels of human exposure and associated health risks. Importance in any assessment is information on the concentration and types of viruses in the untreated wastewater, as well as the degree of removal by each treatment process. However, it is critical that the uncertainty associated with virus concentration and removal or inactivation by wastewater treatment be understood to improve these estimates and identifying research needs. We reviewed the critically literature to assess to identify uncertainty in these estimates. Biological diversity within families and genera of viruses (e.g. enteroviruses, rotaviruses, adenoviruses, reoviruses, noroviruses) and specific virus types (e.g. serotypes or genotypes) creates the greatest uncertainty. These aspects affect the methods for detection and quantification of viruses and anticipated removal efficiency by treatment processes. Approaches to reduce uncertainty may include; 1) inclusion of a virus indicator for assessing efficiency of virus concentration and detection by molecular methods for each sample, 2) use of viruses most resistant to individual treatment processes (e.g. adenoviruses for UV light disinfection and reoviruses for chlorination), 3) data on ratio of virion or genome copies to infectivity in untreated wastewater, and 4) assessment of virus removal at field scale treatment systems to verify laboratory and pilot plant data for virus removal. Copyright © 2018 Elsevier Ltd. All rights reserved.

Feasibility, safety, and economic implications of whey-recovered water in cleaning-in-place systems: A case study on water conservation for the dairy industry.

PubMed

Meneses, Yulie E; Flores, Rolando A

2016-05-01

Water scarcity is threatening food security and business growth in the United States. In the dairy sector, most of the water is used in cleaning applications; therefore, any attempt to support water conservation in these processes will have a considerable effect on the water footprint of dairy products. This study demonstrates the viability for recovering good quality water from whey, a highly pollutant cheese-making by-product, to be reused in cleaning-in-place systems. The results obtained in this study indicate that by using a combined ultrafiltration and reverse osmosis system, 47% of water can be recovered. This system generates protein and lactose concentrates, by-products that once spray-dried fulfill commercial standards for protein and lactose powders. The physicochemical and microbiological quality of the recovered permeate was also analyzed, suggesting suitable properties to be reused in the cleaning-in-place system without affecting the quality and safety of the product manufactured on the cleaned equipment. A cost analysis was conducted for 3 cheese manufacturing levels, considering an annual production of 1, 20, and 225 million liters of whey. Results indicate the feasibility of this intervention in the dairy industry, generating revenues of $0.18, $3.05, and $33.4 million per year, respectively. The findings provide scientific evidence to promote the safety of reuse of reconditioned water in food processing plants, contributing to building a culture of water conservation and sustainable production throughout the food supply chain. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Solar-assisted MED treatment of Eskom power station waste water

NASA Astrophysics Data System (ADS)

Roos, Thomas H.; Rogers, David E. C.; Gericke, Gerhard

2017-06-01

The comparative benefits of multi-effect distillation (MED) used in conjunction with Nano Filtration (NF), Reverse Osmosis (RO) and Eutectic Freeze Crystallization (EFC) are determined for waste water minimization for inland coal fired power stations for Zero Liquid Effluent Discharge (ZLED). A sequence of technologies is proposed to achieve maximal water recovery and brine concentration: NF - physico-chemical treatment - MED - EFC. The possibility of extending the concentration of RO reject arising from minewater treatment at the Lethabo power station with MED alone is evaluated with mineral formation modelling using the thermochemical modelling software Phreeq-C. It is shown that pretreatment is essential to extend the amount of water that can be recovered, and this can be beneficially supported by NF.

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

PubMed

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

2016-05-01

Membrane filtration of ground, surface, or sea water by reverse osmosis results in permeate, which is almost free from minerals. Minerals may be added afterwards, not only to comply with (legal) standards and to enhance chemical stability, but also to improve the taste of drinking water made from permeate. Both the nature and the concentrations of added minerals affect the taste of the water and in turn its acceptance by consumers. The aim of this study was to examine differences in taste between various remineralised drinking waters. Samples selected varied in mineral composition, i.e. tap water, permeate, and permeate with added minerals (40 or 120 mg Ca/L, added as CaCO3, and 4 or 24 mg Mg/L added as MgCl2), as well as commercially available bottled drinking waters, to span a relevant product space in which the remineralised samples could be compared. All samples were analysed with respect to their physical-chemical properties. Sensory profiling was done by descriptive analysis using a trained panel. Significant attributes included taste intensity, the tastes bitter, sweet, salt, metal, fresh and dry mouthfeel, bitter and metal aftertaste, and rough afterfeel. Total dissolved solids (TDS) was a major determinant of the taste perception of water. In general, lowering mineral content in drinking water in the range examined (from <5 to 440 mg/L) shifted the sensory perception of water from fresh towards bitter, dry, and rough sensations. In addition, perceived freshness of the waters correlated positively with calcium concentration. The greatest fresh taste was found for water with a TDS between 190 and 350 mg/L. Remineralisation of water after reverse osmosis can improve drinking quality significantly. Copyright © 2016 Elsevier Ltd. All rights reserved.

Electrochemical treatment of iopromide under conditions of reverse osmosis concentrates--elucidation of the degradation pathway.

PubMed

Lütke Eversloh, C; Henning, N; Schulz, M; Ternes, T A

2014-01-01

Application of reverse osmosis for the reuse of treated wastewater on the one hand offers a way to provide high quality effluent waters. On the other hand reverse osmosis concentrates exhibiting highly concentrated contaminants are produced simultaneously. Electrochemical treatment of those concentrates is regarded as one possible answer to the problem of their disposal into surface waters. Nevertheless, due to the diversity of direct and indirect degradation processes during electrolysis, special care has to be taken about the formation of toxic transformation products (TPs). In this study the electrochemical transformation of the X-ray contrast medium iopromide was investigated as a representative of biologically persistent compounds. For this purpose, anodic oxidation at boron doped diamond as well as cathodic reduction using a platinum electrode were considered. Kinetic analyses revealed a transformation of 100 μM iopromide with first order kinetic constants between 0.6 and 1.6 × 10(-4) s(-1) at the beginning and a subsequent increase of the reaction order due to the influence of secondary oxidants formed during electrolysis. Mineralization up to 96% was achieved after about 7.5 h. At shorter treatment times several oxidatively and reductively formed transformation products were detected, whereas deiodinated iopromide represented the major fraction. Nevertheless, the latter exhibited negligible toxicological relevance according to tests on vibrio fisheri. Additional experiments utilizing a divided cell setup enabled the elucidation of the transformation pathway, whereas emerging TPs could be identified by means of high resolution mass spectrometry and MS(n)-fragmentations. During electrolysis the iodine released from Iopromide was found to 90% as iodide and to 10% as iodate even in the open cell experiments, limiting the potential formation of toxic iodo-disinfection by-products. Chlorinated TPs were not found. Copyright © 2013. Published by Elsevier Ltd.

MODIFIED REVERSE OSMOSIS SYSTEM FOR TREATMENT OF PRODUCED WATERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

T.M. Whitworth; Liangxiong Li

2002-09-15

This report describes work performed during the second year of the project ''Modified reverse osmosis system for treatment of produced waters.'' We performed two series of reverse osmosis experiments using very thin bentonite clay membranes compacted to differing degrees. The first series of 10 experiments used NaCl solutions with membranes that ranged between 0.041 and 0.064mm in thickness. Our results showed compaction of such ultra-thin clay membranes to be problematic. The thickness of the membranes was exceeded by the dimensional variation in the machined experimental cell and this is believed to have resulted in local bypassing of the membrane withmore » a resultant decrease in solute rejection efficiency. In two of the experiments, permeate flow was varied as a percentage of the total flow to investigate results of changing permeate flow on solute rejection. In one experiment, the permeate flow was varied between 2.4 and 10.3% of the total flow with no change in solute rejection. In another experiment, the permeate flow was varied between 24.6 and 52.5% of the total flow. In this experiment, the solute rejection rate decreased as the permeate occupied greater fractions of the total flow. This suggests a maximum solute rejection efficiency for these clay membranes for a permeate flow of between 10.3 and 24.6% of the total; flow. Solute rejection was found to decrease with increasing salt concentration and ranged between 62.9% and 19.7% for chloride and between 61.5 and 16.8% for sodium. Due to problems with the compaction procedure and potential membrane bypassing, these rejection rates are probably not the upper limit for NaCl rejection by bentonite membranes. The second series of four reverse osmosis experiments was conducted with a 0.057mm-thick bentonite membrane and dilutions of a produced water sample with an original TDS of 196,250 mg/l obtained from a facility near Loco Hill, New Mexico, operated by an independent. These experiments tested the separation efficiency of the bentonite membrane for each of the dilutions. We found that membrane efficiency decreased with increasing solute concentration and with increasing TDS. The rejection of SO{sub 4}{sup 2-} was greater than Cl{sup -}. This may be because the SO{sub 4}{sup 2-} concentration was much lower than the Cl{sup -} concentration in the waters tested. The cation rejection sequence varied with solute concentration and TDS. The solute rejection sequence for multi-component solutions is difficult to predict for synthetic membranes; it may not be simple for clay membranes either. The permeate flows in our experiments were 4.1 to 5.4% of the total flow. This suggests that very thin clay membranes may be useful for some separations. Work on development of a spiral-wound clay membrane module found that it is difficult to maintain compaction of the membrane if the membrane is rolled and then inserted in the outer tube. A different design was tried using a cylindrical clay membrane and this also proved difficult to assemble with adequate membrane compaction. The next step is to form the membrane in place using hydraulic pressure on a thin slurry of clay in either water or a nonpolar organic solvent such as ethanol. Technology transfer efforts included four manuscripts submitted to peer-reviewed journals, two abstracts, and chairing a session on clays as membranes at the Clay Minerals Society annual meeting.« less

MODIFIED REVERSE OSMOSIS SYSTEM FOR TREATMENT OF PRODUCED WATERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

T.M. Whitworth; Liangxiong Li

2002-09-15

This report describes work performed during the first year of the project ''Modified Reverse Osmosis System for Treatment of Produced Waters.'' This research project has two objectives. The first objective is to test the use of clay membranes in the treatment of produced waters by reverse osmosis. The second objective is to test the ability of a system patented by the New Mexico Tech Research Foundation to remove salts from reverse osmosis waste streams as a solid. We performed 12 experiments using clay membranes in cross-flow experimental cells. We found that, due to dispersion in the porous frit used adjacentmore » to the membrane, the concentration polarization layer seems to be completely (or nearly completely) destroyed at low flow rates. This observation suggests that clay membranes used with porous frit material many reach optimum rejection rates at lower pumping rates than required for use with synthetic membranes. The solute rejection efficiency decreases with increasing solution concentration. For the membranes and experiments reported here, the rejection efficiency ranged from 71% with 0.01 M NaCl solution down to 12% with 2.3 M NaCl solution. More compacted clay membranes will have higher rejection capabilities. The clay membranes used in our experiments were relatively thick (approximately 0.5 mm). The active layer of most synthetic membranes is only 0.04 {micro}m (0.00004 mm), approximately 1250 times thinner than the clay membranes used in these experiments. Yet clay membranes as thin as 12 {micro}m have been constructed (Fritz and Eady, 1985). Since Darcy's law states that the flow through a material of constant permeability is inversely proportional to it's the material's thickness, then, based on these experimental observations, a very thin clay membrane would be expected to have much higher flow rates than the ones used in these experiments. Future experiments will focus on testing very thin clay membranes. The membranes generally exhibited reasonable stable rejection rates over time for chloride for a range of concentrations between 0.01 and 2.5 M. One membrane ran in excess of three months with no apparent loss of usability. This suggests that clay membranes may have a long useable life. Twenty different hyperfiltration-induced solute precipitation experiments were either attempted or completed and are reported here. The results of these experiments suggest that hyperfiltration-induced solute precipitation is possible, even for very soluble substances such as NaCl. However, the precipitation rates obtained in the laboratory do not appear to be adequate for commercial application at this time. Future experiments will focus on making the clay membranes more compact and thinner in order to obtain higher flux rates. Two alternative methods of removing solutes from solution, for which the New Mexico Tech Research Foundation is preparing patent applications, are also being investigated. These methods will be described in the next annual report after the patent applications are filed. Technology transfer efforts included two meetings (one in Farmington NM, and one in Hobbs, NM) where the results of this research were presented to independent oil producers and other interested parties. In addition, members of the research team gave seven presentations concerning this research and because of this research project T. M. (Mike) Whitworth was asked to sit on the advisory board for development of a new water treatment facility for the City of El Paso, Texas. Several papers are in preparation for submission to peer-reviewed journals based on the data presented in this report.« less

Combination of forward osmosis (FO) process with coagulation/flocculation (CF) for potential treatment of textile wastewater.

PubMed

Han, Gang; Liang, Can-Zeng; Chung, Tai-Shung; Weber, Martin; Staudt, Claudia; Maletzko, Christian

2016-03-15

A novel combination of forward osmosis (FO) process with coagulation/flocculation (CF) (FO-CF) has been experimentally conceived for the treatment and reuse of textile wastewater. FO is employed to spontaneously recover water from the wastewater via osmosis and thus effectively reduces its volume with a dramatically enhanced dye concentration. CF is then applied to precipitate and remove dyes from the FO concentrated stream with much improved efficiency and reduced chemical dosage. The FO-CF hybrid system exhibits unique advantages of high water flux and recovery rate, well controlled membrane fouling, high efficiency, and minimal environmental impact. Using a lab-made thin-film composite (TFC) FO membrane, an initial water flux (Jw) of 36.0 L m(-2) h(-1) with a dye rejection of 99.9% has been demonstrated by using 2 M NaCl as the draw solution and synthetic textile wastewater containing multiple textile dyes, inorganic salts and organic additives as the feed under the FO mode. The Jw could be maintained at a high value of 12.0 L m(-2) h(-1) even when the recovery rate of the wastewater reaches 90%. Remarkable reverse fouling behavior has also been observed where the Jw of the fouled membrane can be almost fully restored to the initial value by physical flushing without using any chemicals. Due to the great dye concentration in the FO concentrated wastewater stream, the CF process could achieve more than 95% dye removal with a small dosage of coagulants and flocculants at 500-1000 ppm. The newly developed FO-CF hybrid process may open up new exploration of alternative technologies for the effective treatment and reuse of textile effluents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of solute penetration across the polysulfone membrane with vitamin E coating.

PubMed

Yamashita, Akihiro C; Masaki, Hidenori; Kobayashi, Eisuke; Sukegawa, Takeshi

2015-10-01

Vitamin E (vit E) is coated on polysulfone (PS) dialysis membrane for antioxidative purpose. The membrane, however, has not yet been evaluated from the mass transfer point of view. We investigated this PS membrane with and without vit E coating in vitro ultrafiltration experiments to identify whether or not the coating influences the mass transfer. Dialyzers that included PS membrane with and without vit E coating were investigated. Aqueous test solution of various solutes including vitamin B12 (VB12 , MW1355), chymotrypsin (chymo, MW25000), and albumin (alb, MW66000) was prepared, and normal ultrafiltration experiments were performed at 310 K. Reverse ultrafiltration experiments in which test solution was filtered from outside to inside the hollow fiber were also performed. Sieving coefficients (SC) were computed for evaluation. SC for VB12 was the same regardless of vit E coating; however, chymo was 0.82 ± 0.01 and 0.86 ± 0.01, respectively, for the membrane with and without vit E. Thus, it would be understood that vit E coating reduces the pore size of the membrane, resulting the reduced transport of larger solutes. Like other PS membrane, SC for alb was decreased over time regardless of vit E coating. More importantly, although the steady-state SC for alb was almost identical in two membranes, PS without vit E showed much greater decrease for the first 2 h, while that with vit E showed very little decrease over time, which suggested the reduced fouling effect due to vit E coating. All the SC values found in reverse ultrafiltration were higher than those found in normal ultrafiltration; moreover, the degree of increase with chymo was approximately 5%, whereas that with alb was approximately 430%, which may be explained by a new model in which wedge effect is taken into consideration for the membrane transport. Vit E coating not only has antioxidative effect but also reduces the fouling that is usually caused by various proteins. © 2015 International Society for Hemodialysis.

EVALUATING VARIOUS ADSORBENTS AND MEMBRANES FOR REMOVING RADIUM FROM GROUNDWATER

EPA Science Inventory

Field studies were conducted in Lemont, Ill., to evaluate specific adsorbents and reverse osmosis (RO) membranes for removing radium from groundwater. A radium-selective complexer and barium-sulfate-loaded alumina appeared to have the best potential for low-cost adsorption of ra...

Removing Arsenic with a Softening/RO Combo

EPA Science Inventory

This paper provides a very short summary of the arsenic demonstration program and the limited test results from the point-of-use (POU), reverse osmosis (RO) project in Homedale, ID. Preformance data is presented on the effectiveness of the POU treatment system to remove arseni...

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

PubMed

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.

Removal of Cd(II) ions from aqueous solution and industrial effluent using reverse osmosis and nanofiltration membranes.

PubMed

Kheriji, Jamel; Tabassi, Dorra; Hamrouni, Béchir

2015-01-01

Industrial effluents loaded with cadmium have contributed to the pollution of the environment and health troubles for humans. Therefore, these effluents need treatment to reduce cadmium concentration before releasing them to public sewage. The purpose of the research is to study the major role of reverse osmosis (RO) and nanofiltration (NF) processes, which can contribute to the removal of cadmium ions from model water and wastewater from the battery industry. For this reason, two RO and two nanofiltration membranes have been used. The effects of feed pressure, concentration, ionic strength, nature of anion associated with cadmium and pH on the retention of Cd(II) were studied with model solutions. Thereafter, NF and RO membranes were used to reduce cadmium ions and total salinity of battery industry effluent. Among these membranes, there are only three which eliminate more than 95% of cadmium. This was found to depend on operating conditions. It is worth noting that the Spiegler-Kedem model was applied to fit the experimental results.

Novel reverse osmosis membranes composed of modified PVA/Gum Arabic conjugates: Biofouling mitigation and chlorine resistance enhancement.

PubMed

Falath, Wail; Sabir, Aneela; Jacob, Karl I

2017-01-02

A novel crosslinked Poly (vinyl alcohol) (PVA) reverse osmosis (RO) thin film membrane conjugated with Gum Arabic (GA) with superb performance and features was synthesized for water desalination. RO membrane desalination parameters, such as hydrophilicity, surface roughness, water permeability, salt rejection, Chlorine resistance and biofouling resistance were evaluated using a dead end RO filtration unit. The incorporation of Pluronic F127 and the conjugation of Gum Arabic improved the overall RO performance of the membranes. This study has shown that the membrane PVA-GA-5 that contains 0.9wt% Gum Arabic provided excellent permeation, salt rejection, Chlorine and biofouling resistance and mechanical strength. The most remarkable result to arise from this research is that the overall RO performance enhancement has been achieved while utilizing PVA/Gum Arabic as a separation layer without the use of a substrate, which eliminates negative effects associated with the use of a substrate like internal concentration polarization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Removal of bisphenol A (BPA) from water by various nanofiltration (NF) and reverse osmosis (RO) membranes.

PubMed

Yüksel, Suna; Kabay, Nalan; Yüksel, Mithat

2013-12-15

The removal of an endocrine disrupting compound, bisphenol A (BPA), from model solutions by selected nanofiltration (NF) and reverse osmosis (RO) membranes was studied. The commercially available membranes NF 90, NF 270, XLE BWRO, BW 30 (Dow FilmTech), CE BWRO and AD SWRO (GE Osmonics) were used to compare their performances for BPA removal. The water permeability coefficients, rejection of BPA and permeate flux values were calculated for all membranes used. No significant changes in their BPA removal were observed for all tight polyamide based NF and RO membranes tested except for loose NF 270 membrane. The polyamide based membranes exhibited much better performance than cellulose acetate membrane for BPA removal. Almost a complete rejection (≥ 98%) for BPA was obtained with three polyamide based RO membranes (BW 30, XLE BWRO and AD SWRO). But cellulose acetate based CE BWRO membrane offered a low and variable (10-40%) rejection for BPA. Copyright © 2013 Elsevier B.V. All rights reserved.

Reverse osmosis for wash water recovery in space vehicles.

NASA Technical Reports Server (NTRS)

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

1973-01-01

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

Bacterial bioluminescence response to long-term exposure to reverse osmosis treated effluents from dye industries.

PubMed

Ravindran, J; Manikandan, B; Shirodkar, P V; Francis, K X; Mani Murali, R; Vethamony, P

2014-10-01

The bacterial bioluminescence assay is one of the novel means for toxicity detection. The bioluminescence response of 2 marine bioluminescent bacteria was tested upon their long-term exposure to 9 different reverse osmosis (RO) rejects with varying chemical composition sampled from various dye industries. Bioluminescent bacteria were cultured in the RO reject samples, at different concentrations, and their growth rate and luminescence was measured for 24 h. The RO reject samples caused sublethal effects upon exposure and retarded the growth of bacteria, confirming their toxic nature. Further, continuation of the exposure showed that the initial luminescence, though reduced, recovered and increased beyond the control cultures irrespective of cell density, and finally decreased once again. The present study emphasizes the need of evolving a long-term exposure assay and shows that the method followed in this study is suitable to evaluate the toxicants that exert delayed toxicity, using lower concentrations of toxicants as well as coloured samples.

Membrane rejection of nitrogen compounds

NASA Technical Reports Server (NTRS)

Lee, S.; Lueptow, R. M.

2001-01-01

Rejection characteristics of nitrogen compounds were examined for reverse osmosis, nanofiltration, and low-pressure reverse osmosis membranes. The rejection of nitrogen compounds is explained by integrating experimental results with calculations using the extended Nernst-Planck model coupled with a steric hindrance model. The molecular weight and chemical structure of nitrogen compounds appear to be less important in determining rejection than electrostatic properties. The rejection is greatest when the Donnan potential exceeds 0.05 V or when the ratio of the solute radius to the pore radius is greater than 0.8. The transport of solute in the pore is dominated by diffusion, although convective transport is significant for organic nitrogen compounds. Electromigration contributes negligibly to the overall solute transport in the membrane. Urea, a small organic compound, has lower rejection than ionic compounds such as ammonium, nitrate, and nitrite, indicating the critical role of electrostatic interaction in rejection. This suggests that better treatment efficiency for organic nitrogen compounds can be obtained after ammonification of urea.

Reverse osmosis membrane composition, structure and performance modification by bisulphite, iron(III), bromide and chlorite exposure.

PubMed

Ferrer, O; Gibert, O; Cortina, J L

2016-10-15

Reverse osmosis (RO) membrane exposure to bisulphite, chlorite, bromide and iron(III) was assessed in terms of membrane composition, structure and performance. Membrane composition was determined by Rutherford backscattering spectrometry (RBS) and membrane performance was assessed by water and chloride permeation, using a modified version of the solution-diffusion model. Iron(III) dosage in presence of bisulphite led to an autooxidation of the latter, probably generating free radicals which damaged the membrane. It comprised a significant raise in chloride passage (chloride permeation coefficient increased 5.3-5.1 fold compared to the virgin membrane under the conditions studied) rapidly. No major differences in terms of water permeability and membrane composition were observed. Nevertheless, an increase in the size of the network pores, and a raise in the fraction of aggregate pores of the polyamide (PA) layer were identified, but no amide bond cleavage was observed. These structural changes were therefore, in accordance with the transport properties observed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reverse osmosis as a potential technique to improve antioxidant properties of fruit juices used for functional beverages.

PubMed

Gunathilake, K D P P; Yu, Li Juan; Rupasinghe, H P Vasantha

2014-04-01

Reverse osmosis (RO) as a potential technique to improve the antioxidant properties of cranberry, blueberry and apple juices was evaluated for the formulation of a functional beverage. The effects of temperature (20-40 °C) and trans-membrane pressure (25-35 bars) on physico-chemical and antioxidant properties of fruit juices were evaluated to optimize the operating parameters for each fruit juice. There was no significant effect on any quality parameters of fruit juices under studied operating parameters of RO. However, total soluble solid, total acidity and colour (a(∗)) of the concentrated juices increased in proportion to their volumetric concentrations. Antioxidant capacity measured by FRAP assay of concentrated apple, blueberry and cranberry juice was increased by 40%, 34%, and 30%, respectively. LDL oxidation inhibition by concentrated blueberry and cranberry juice was increased up to 41% and 45%, respectively. The results suggest that RO can be used for enhancing the health promoting properties of fruit juices. Copyright © 2013 Elsevier Ltd. All rights reserved.

A new flat sheet membrane bioreactor hybrid system for advanced treatment of effluent, reverse osmosis pretreatment and fouling mitigation.

PubMed

Hosseinzadeh, Majid; Bidhendi, Gholamreza Nabi; Torabian, Ali; Mehrdadi, Naser; Pourabdullah, Mehdi

2015-09-01

This paper introduces a new hybrid electro membrane bioreactor (HEMBR) for reverse osmosis (RO) pretreatment and advanced treatment of effluent by simultaneously integrating electrical coagulation (EC) with a membrane bioreactor (MBR) and its performance was compared with conventional MBR. Experimental results and their statistical analysis showed removal efficiency for suspended solids (SS) of almost 100% for both reactors. HEMBR removal of chemical oxygen demand (COD) improved by 4% and membrane fouling was alleviated according to transmembrane pressure (TMP). The average silt density index (SDI) of HEMBR permeate samples was slightly better indicating less RO membrane fouling. Moreover, based on the SVI comparison of two reactor biomass samples, HEMBR showed better settling characteristics which improved the dewaterability and filterability of the sludge. Analysis the change of membrane surfaces and the cake layer formed over them through field emission scanning electron microscopy (FESEM) and X-ray fluorescence spectrometer (XRF) were also discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

PubMed

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.

Multi-Response Optimization of Process Parameters for Imidacloprid Removal by Reverse Osmosis Using Taguchi Design.

PubMed

Genç, Nevim; Doğan, Esra Can; Narcı, Ali Oğuzhan; Bican, Emine

2017-05-01

  In this study, a multi-response optimization method using Taguchi's robust design approach is proposed for imidacloprid removal by reverse osmosis. Tests were conducted with different membrane type (BW30, LFC-3, CPA-3), transmembrane pressure (TMP = 20, 25, 30 bar), volume reduction factor (VRF = 2, 3, 4), and pH (3, 7, 11). Quality and quantity of permeate are optimized with the multi-response characteristics of the total dissolved solid (TDS), conductivity, imidacloprid, and total organic carbon (TOC) rejection ratios and flux of permeate. The optimized conditions were determined as membrane type of BW30, TMP 30 bar, VRF 3, and pH 11. Under these conditions, TDS, conductivity, imidacloprid, and TOC rejections and permeate flux were 97.50 97.41, 97.80, 98.00% and 30.60 L/m2·h, respectively. Membrane type was obtained as the most effective factor; its contribution is 64%. The difference between the predicted and observed value of multi-response signal/noise (MRSN) is within the confidence interval.

Separation of sodium chloride from the evaporated residue of the reverse osmosis reject generated in the leather industry--optimization by response surface methodology.

PubMed

Boopathy, R; Sekaran, G

2014-08-01

Reverse osmosis (RO) concentrate is being evaporated by solar/thermal evaporators to meet zero liquid discharge standards. The resulted evaporated residue (ER) is contaminated with both organic and inorganic mixture of salts. The generation of ER is exceedingly huge in the leather industry, which is being collected and stored under the shelter to avoid groundwater contamination by the leachate. In the present investigation, a novel process for the separation of sodium chloride from ER was developed, to reduce the environmental impact on RO concentrate discharge. The sodium chloride was selectively separated by the reactive precipitation method using hydrogen chloride gas. The selected process variables were optimized for maximum yield ofNaCl from the ER (optimum conditions were pH, 8.0; temperature, 35 degrees C; concentration of ER, 600 g/L and HCl purging time, 3 min). The recovered NaCl purity was verified using a cyclic voltagramm.

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

PubMed

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.

Selection of suitable fertilizer draw solute for a novel fertilizer-drawn forward osmosis-anaerobic membrane bioreactor hybrid system.

PubMed

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

2016-06-01

In this study, a protocol for selecting suitable fertilizer draw solute for anaerobic fertilizer-drawn forward osmosis membrane bioreactor (AnFDFOMBR) was proposed. Among eleven commercial fertilizer candidates, six fertilizers were screened further for their FO performance tests and evaluated in terms of water flux and reverse salt flux. Using selected fertilizers, bio-methane potential experiments were conducted to examine the effect of fertilizers on anaerobic activity due to reverse diffusion. Mono-ammonium phosphate (MAP) showed the highest biogas production while other fertilizers exhibited an inhibition effect on anaerobic activity with solute accumulation. Salt accumulation in the bioreactor was also simulated using mass balance simulation models. Results showed that ammonium sulfate and MAP were the most appropriate for AnFDFOMBR since they demonstrated less salt accumulation, relatively higher water flux, and higher dilution capacity of draw solution. Given toxicity of sulfate to anaerobic microorganisms, MAP appears to be the most suitable draw solution for AnFDFOMBR. Copyright © 2016 Elsevier Ltd. All rights reserved.

A hybrid regenerative water recovery system for lunar/Mars life support applications

NASA Technical Reports Server (NTRS)

Verostko, Charles E.; Edeen, Marybeth A.; Packham, Nigel J. C.

1992-01-01

Long-duration manned space missions will require integrated biological and physicochemical processes for recovery of resources from wastes. This paper discusses a hybrid regenerative biological and physicochemical water recovery system designed and built at NASA's Crew and Thermal Systems Division at Johnson Space Center. The system is sized for a four-person crew and consists of a two-stage, aerobic, trickling filter bioreactor; a reverse osmosis system; and a photocatalytic oxidation system. The system was designed to accommodate high organic and inorganic loadings and a low hydraulic loading. The bioreactor was designed to oxidize organics to carbon dioxide and water; the reverse osmosis system reduces inorganic content to potable quality; and the photocatalytic oxidation unit removes residual organic impurities (part per million range) and provides in situ disinfection. The design and performance of the hybrid system for producing potable/hygiene water is described. Aspects of the system such as closure, automation and integration are discussed and preliminary results presented.

Treatment of greywater by forward osmosis technology: role of the operating temperature.

PubMed

Wang, Ce; Li, Yongmei; Wang, Yanqiang

2018-06-04

Effects of operating conditions were investigated in terms of water flux, reverse salt flux (RSF) and pollutant rejection in a forward osmosis (FO) membrane system treating synthetic greywater. Changing cross-flow velocity had a slight impact on the performance of the FO membrane. Elevating operating temperature was more effective than increasing draw solution concentration to enhance the water flux. Further observation on the effect of heating mode showed that when the temperature was increased from 20 to 30°C, heating the feed solution (FS) side was better than heating the draw solution (DS) side or heating both sides; further increasing the temperature to 40 and 50°C, heating both the FS and DS achieved much higher water flux compared with only increasing the FS or DS temperature. Under isothermal conditions, a higher water flux and a lower RSF were achieved at 40°C than at other temperatures. Changing either FS or DS temperature had similar influences on water flux and RSF. The FO process revealed high rejection of nitrate (95.7%-100%), ammonia nitrogen (98.8%-100%), total nitrogen (97.4%-99.9%), linear alkylbenzene sulfonate (100%) and Mg (97.5%-100%). A mathematical model that could well simulate the water flux evolution in the present FO system was recommended.

Effect of hydraulically reversible and hydraulically irreversible fouling on the removal of MS2 and φX174 bacteriophage by an ultrafiltration membrane.

PubMed

ElHadidy, Ahmed M; Peldszus, Sigrid; Van Dyke, Michele I

2014-09-15

The effect of membrane fouling on the removal of enteric virus surrogates MS2 and φX174 bacteriophage by an ultrafiltration membrane was assessed under simulated full-scale drinking water treatment operating conditions. Filtration experiments of up to 8 days using either river or lake water ascertained how the membrane fouling layer affected virus removal. Organic carbon fractionation techniques identified potential foulants, including biopolymers, in the feed water and in the permeate. Hydraulically irreversible fouling could greatly improve the removal of both viruses at moderate and severe fouling conditions by up to 2.5 logs. Hydraulically reversible fouling increased virus removal only slightly, and increased removal of >0.5 log for both phage were only obtained under severe fouling conditions. The increase in virus removal due to irreversible and reversible fouling differed between the two water sources. As the degree of fouling increased, differences between the removal of the two phage decreased. Maintenance cleaning partially removed membrane foulants, however virus removal following maintenance cleaning was lower than that of the fouled membrane, it remained higher than that of the clean membrane. Copyright © 2014 Elsevier Ltd. All rights reserved.

Asymmetrical reverse vortex flow due to induced-charge electro-osmosis around carbon stacking structures.

PubMed

Sugioka, Hideyuki

2011-05-01

Broken symmetry of vortices due to induced-charge electro-osmosis (ICEO) around stacking structures is important for the generation of a large net flow in a microchannel. Following theoretical predictions in our previous study, we herein report experimental observations of asymmetrical reverse vortex flows around stacking structures of carbon posts with a large height (~110 μm) in water, prepared by the pyrolysis of a photoresist film in a reducing gas. Further, by the use of a coupled calculation method that considers boundary effects precisely, the experimental results, except for the problem of anomalous flow reversal, are successfully explained. That is, unlike previous predictions, the precise calculations here show that stacking structures accelerate a reverse flow rather than suppressing it for a microfluidic channel because of the deformation of electric fields near the stacking portions; these structures can also generate a large net flow theoretically in the direction opposite that of a previous prediction for a standard vortex flow. Furthermore, by solving the one-dimensional Poisson-Nernst-Plank (PNP) equations in the presence of ac electric fields, we find that the anomalous flow reversal occurs by the phase retardation between the induced diffuse charge and the tangential electric field. In addition, we successfully explain the nonlinearity of the flow velocity on the applied voltage by the PNP analysis. In the future, we expect to improve the pumping performance significantly by using stacking structures of conductive posts along with a low-cost process. © 2011 American Physical Society

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - PHYSICAL REMOVAL OF PARTICULATE CONTAMINANTS IN DRINKING WATER: POLYMEM UF 120 S2 ULTRAFILTRATION MEMBRANE MODULE, LUXENBURG, WISCONSIN

EPA Science Inventory

Verification testing of the Polymem UF120 S2 Ultrafiltration Membrane Module was conducted over a 46-day period at the Green Bay Water Utility Filtration Plant, Luxemburg, Wisconsin. The ETV testing described herein was funded in conjunction with a 12-month membrane pilot study f...

Domestic wash water reclamation

NASA Technical Reports Server (NTRS)

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

1974-01-01

System consists of filtration unit, reverse-osmosis module, tanks, pumps, plumbing, and various gauges, meters, and valves. After water is used in washing machine or shower, it is collected in holding tank. Water is pumped through series of five particulate filters. Pressure tank supplies processed water to commode water closet.

Disinfection Byproduct Formation in Reverse-Osmosis Concentrated and Lyophilized Natural Organic Matter from a Drinking Water Source

EPA Science Inventory

Drinking water treatment and disinfection byproduct (DBP) research can be complicated by natural organic matter (NOM) temporal variability. NOM preservation by lyophilization (freeze-drying) has been long practiced to address this issue; however, its applicability for drinking wa...

Improved ion exchange membrane

NASA Technical Reports Server (NTRS)

Rembaum, A.; Yen, S. P. S.; Klein, E.

1975-01-01

Membrane, made from commercially-available hollow fibers, is used in reverse osmosis, or dialysis. Fiber has skin layers which pass only small molecules. Macromolecules cannot penetrate skin. Fibers can also be used to remove other undesirable anions, such as phosphate, sulfate, carbonate, and uranium in form of uranium-sulfate complex.

Potential use of reverse osmosis in managing saltwater waste collected at road-salt storage facilites [sic].

DOT National Transportation Integrated Search

2006-01-01

The implementation of its anti-icing program comprises a large part of the Virginia Department of Transportation's (VDOT) maintenance effort. Earlier research confirmed that VDOT captures a large volume of salt-laden stormwater runoff at its 300+ sal...

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

EPA Science Inventory

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

Forming "dynamic" membranes on stainless steel

NASA Technical Reports Server (NTRS)

Brandon, C. A.; Gaddis, J. L.

1979-01-01

"Dynamic" zirconium polyacrylic membrane is formed directly on stainless steel substrate without excessive corrosion of steel. Membrane is potentially useful in removal of contaminated chemicals from solution through reversed osmosis. Application includes use in filtration and desalination equipment, and in textile industry for separation of dyes from aqueous solvents.

POINT-OF-USE TREATMENT OF DRINKING WATER IN SAN YSIDRO, NM

EPA Science Inventory

This study was conducted to determine whether point-of-use (POU) reverse osmosis (RO) units could satisfactorily function in lieu of central treatment to remove arsenic and fluoride from the drinking water supply of San Ysidro, NM. POU treatment was evaluated for removal efficien...

SEPARATION OF HAZARDOUS ORGANICS BY LOW PRESSURE REVERSE OSMOSIS MEMBRANES - PHASE II FINAL REPORT

EPA Science Inventory

Extensive experimental studies showed that thin-film, composite membranes can be used effectively for the separation of selected hazardous organic compounds. This waste treatment technique offers definite advantages in terms of high solute separations at low pressures (<2MPa) and...

Membrane-Filtered Olive Mill Wastewater: Quality Assessment of the Dried Phenolic-Rich Fraction.

PubMed

Sedej, Ivana; Milczarek, Rebecca; Wang, Selina C; Sheng, Runqi; de Jesús Avena-Bustillos, Roberto; Dao, Lan; Takeoka, Gary

2016-04-01

A current trend in olive mill wastewater (OMWW) management is to not only decrease environmental pollution but also to extract and utilize valuable by-products. Therefore, the objectives of this study were to explore different techniques for drying a phenolic-rich membrane filtration fraction of OMWW and compare the techniques in terms of the dried product quality and feasibility of the process. The OMWW from 2 (3-phase and 2-phase) California mills was subjected to a 2-step membrane filtration process using a novel vibratory system. The reverse osmosis retentate (RO-R) is a phenolic-rich coproduct stream, and the reverse osmosis permeate is a near-pure water stream that could be recycled into the milling process. Spray-, freeze-, and infrared-drying were applied to obtain solid material from the RO-R. Drying of the RO-R was made possible only with addition of 10% maltodextrin as a carrier. The total soluble phenolics in dried RO-R were in the range 0.15 to 0.58 mg gallic acid equivalents/g of dry weight for 2-phase RO-R, and 1.38 to 2.17 mg gallic acid equivalents/g of dry weight for the 3-phase RO-R. Spray-dried RO-R from 3-phase OMWW showed remarkable antioxidant activity. Protocatechuic acid, tyrosol, vanillic acid, and p-coumaric acid were quantified in all dried RO-R, whereas 3-hydroxytyrosol was found in 3-phase dried RO-R. This combination of separation and drying technologies helps to add value and shelf-stability to an olive oil by-product and increase environmental sustainability of its production. © 2016 Institute of Food Technologists®

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

PubMed

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.

Spatial and temporal evolution of organic foulant layers on reverse osmosis membranes in wastewater reuse applications.

PubMed

Farias, Elizabeth L; Howe, Kerry J; Thomson, Bruce M

2014-07-01

Advanced treatment to remove trace constituents and emerging contaminants is an important consideration for wastewater treatment for potable reuse, and reverse osmosis (RO) can be a suitable technology to provide the necessary level of treatment. However, membrane fouling by biological and organic matter is a concern. This research examined the development of the RO membrane fouling layer using a bench-scale membrane bioreactor operating at different solids retention times (SRTs), followed by a custom-designed RO test cell. The RO test cell contained stacked plates that sandwich five sheets of RO membrane material, which can be extracted for autopsy at separate times over the course of an experiment without disturbing the remaining membranes. The MBR-RO system was run continuously for 2 weeks at each SRT. The RO membranes were stained for live and dead cells, protein, and carbohydrate-like materials, and visualized using confocal laser scanning microscopy. Images of the stained foulant layers were obtained at different depths within the foulant layer at each time point for all SRT conditions. As the RO foulant layer developed, changes occurred in the distribution and morphology of the live cells and carbohydrates, but not the proteins. These trends were similar for all three SRT conditions tested. RO membrane fouling increased with increased MBR SRT, and the highest SRT had the highest ratios of live to dead cells and carbohydrate-like material to dead cells. The autopsied membranes were also analyzed for protein and carbohydrate content, and it was found that the carbohydrate concentration on the membranes after 14 days increased as the SRT increased. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

PubMed

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).

MEETING IN CHARLOTTE: SOLID-PHASE EXTRACTION OF 35 DBPS WITH ANALYSIS BY GC/ECD AND GC/MS

EPA Science Inventory

An analytical method for 35 disinfection by-products (DBPs) was developed for a U.S. Environmental Protection Agency health effects study. A toxicological evaluation was conducted on drinking water that was scaled-up (using reverse osmosis) by concentrating the total organic car...

Emerging investigators series: prospects and challenges for high-pressure reverse osmosis in minimizing concentrated waste streams

DOE PAGES

Schantz, A. Benjamin; Xiong, Boya; Dees, Elizabeth; ...

2018-01-01

If challenges such as mechanical stability, scaling, biofouling and concentration polarization at high pressures are addressed, high-pressure RO could be used to efficiently remove water from high-salinity waste brines as part of a zero-liquid-discharge disposal process.

SOLID-PHASE EXTRACTION OF 35 DBPS WITH ANALYSIS BY GC/ECD AND GC/MS

EPA Science Inventory

An analytical method for 35 disinfection by-products (DBPs) was developed for a U.S. Environmental Protection Agency (EPA) health effects study. A toxicological evaluation was conducted on drinking water that was "scaled-up" using reverse osmosis (RO) by concentrating the total ...

SOLID-PHASE EXTRACTION OF 35 DBPS WITH ANALYSIS BY GC/ECD AND GC/MS

EPA Science Inventory

An analytical method for 35 disinfection by-products (DBPs) was developed for a U.S. Environmental Protection Agency (EPA) health effects study. A toxicological evaluation was conducted on drinking water that was ‘scaled-up’ using reverse osmosis (RO) by concentrating the total o...

SOLID-PHASE EXTRACTION OF 35 DBPS WITH ANALYSIS BY GC/ECD AND GC/MS 2007

EPA Science Inventory

An analytical method for 35 disinfection by-products (DBPs) was developed for a U.S. Environmental Protection Agency (EPA) health effects study. A toxicological evaluation was conducted on drinking water that was ‘scaled-up’ using reverse osmosis (RO) by concentrating the total o...

High-Flow Asymmetric Reverse-Osmosis Membranes

NASA Technical Reports Server (NTRS)

Katz, M. C.; Wydeven, T. J.

1984-01-01

Water-soluble polymer membrane insolubilized by transition-metal salt. Thin layer of lower permeability material joined with thicker layer of highpermeability material. Two layers chemically identical or chemically distinct. They differ in density, compactness or other respects. Used to purify or desalinate seawater, brackish water, or industrial or domestic wastewater.

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

EPA Science Inventory

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

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

EPA Science Inventory

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

The growth of Scenedesmus quadricauda in RO concentrate and the impacts on refractory organic matter, Escherichia coli, and trace organic compounds

EPA Science Inventory

This study achieves a better operational simplicity for the phycoremediation of reverse osmosis (RO) concentrate using Scenedesmus quadricauda microalgae. Under continuous illumination with CO2 supplementation, algal growth in the RO concentrate resulted in a conversion of polyme...

Emerging investigators series: prospects and challenges for high-pressure reverse osmosis in minimizing concentrated waste streams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schantz, A. Benjamin; Xiong, Boya; Dees, Elizabeth

If challenges such as mechanical stability, scaling, biofouling and concentration polarization at high pressures are addressed, high-pressure RO could be used to efficiently remove water from high-salinity waste brines as part of a zero-liquid-discharge disposal process.

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

PubMed Central

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

Membrane scaling and flux decline during fertiliser-drawn forward osmosis desalination of brackish groundwater.

PubMed

Phuntsho, Sherub; Lotfi, Fezeh; Hong, Seungkwan; Shaffer, Devin L; Elimelech, Menachem; Shon, Ho Kyong

2014-06-15

Fertiliser-drawn forward osmosis (FDFO) desalination has been recently studied as one feasible application of forward osmosis (FO) for irrigation. In this study, the potential of membrane scaling in the FDFO process has been investigated during the desalination of brackish groundwater (BGW). While most fertilisers containing monovalent ions did not result in any scaling when used as an FO draw solution (DS), diammonium phosphate (DAP or (NH4)2HPO4) resulted in significant scaling, which contributed to severe flux decline. Membrane autopsy using scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD) analysis indicated that the reverse diffusion of DAP from the DS to the feed solution was primarily responsible for scale formation during the FDFO process. Physical cleaning of the membrane with deionised water at varying crossflow velocities was employed to evaluate the reversibility of membrane scaling and the extent of flux recovery. For the membrane scaled using DAP as DS, 80-90% of the original flux was recovered when the crossflow velocity for physical cleaning was the same as the crossflow velocity during FDFO desalination. However, when a higher crossflow velocity or Reynolds number was used, the flux was recovered almost completely, irrespective of the DS concentration used. This study underscores the importance of selecting a suitable fertiliser for FDFO desalination of brackish groundwater to avoid membrane scaling and severe flux decline. Copyright © 2014 Elsevier Ltd. All rights reserved.

Space Product Development (SPD)

NASA Image and Video Library

2003-01-12

Experiments to seek solutions for a range of biomedical issues are at the heart of several investigations that will be hosted by the Commercial Instrumentation Technology Associates (ITA), Inc. Biomedical Experiments (CIBX-2) payload. CIBX-2 is unique, encompassing more than 20 separate experiments including cancer research, commercial experiments, and student hands-on experiments from 10 schools as part of ITA's ongoing University Among the Stars program. This drawing depicts a cross-section of a set of Dual-Materials Dispersion Apparatus (DMDA) specimen wells, one of which can include a reverse osmosis membrane to dewater a protein solution and thus cause crystallization. Depending on individual needs, two or three wells may be used, the membrane may be absent, or other proprietary enhancements may be present. The experiments are sponsored by NASA's Space Product Development Program (SPD).

Supercritical water oxidation - Microgravity solids separation

NASA Technical Reports Server (NTRS)

Killilea, William R.; Hong, Glenn T.; Swallow, Kathleen C.; Thomason, Terry B.

1988-01-01

This paper discusses the application of supercritical water oxidation (SCWO) waste treatment and water recycling technology to the problem of waste disposal in-long term manned space missions. As inorganic constituents present in the waste are not soluble in supercritical water, they must be removed from the organic-free supercritical fluid reactor effluent. Supercritical water reactor/solids separator designs capable of removing precipitated solids from the process' supercritical fluid in zero- and low- gravity environments are developed and evaluated. Preliminary experiments are then conducted to test the concepts. Feed materials for the experiments are urine, feces, and wipes with the addition of reverse osmosis brine, the rejected portion of processed hygiene water. The solid properties and their influence on the design of several oxidation-reactor/solids-separator configurations under study are presented.

Dual-Materials Dispersion Apparatus

NASA Technical Reports Server (NTRS)

2003-01-01

Experiments to seek solutions for a range of biomedical issues are at the heart of several investigations that will be hosted by the Commercial Instrumentation Technology Associates (ITA), Inc. Biomedical Experiments (CIBX-2) payload. CIBX-2 is unique, encompassing more than 20 separate experiments including cancer research, commercial experiments, and student hands-on experiments from 10 schools as part of ITA's ongoing University Among the Stars program. This drawing depicts a cross-section of a set of Dual-Materials Dispersion Apparatus (DMDA) specimen wells, one of which can include a reverse osmosis membrane to dewater a protein solution and thus cause crystallization. Depending on individual needs, two or three wells may be used, the membrane may be absent, or other proprietary enhancements may be present. The experiments are sponsored by NASA's Space Product Development Program (SPD).

Demineralization of drinking water: Is it prudent?

PubMed

Verma, K C; Kushwaha, A S

2014-10-01

Water is the elixir of life. The requirement of water for very existence of life and preservation of health has driven man to devise methods for maintaining its purity and wholesomeness. The water can get contaminated, polluted and become a potential hazard to human health. Water in its purest form devoid of natural minerals can also be the other end of spectrum where health could be adversely affected. Limited availability of fresh water and increased requirements has led to an increased usage of personal, domestic and commercial methods of purification of water. Desalination of saline water where fresh water is in limited supply has led to development of the latest technology of reverse osmosis but is it going to be safe to use such demineralized water over a long duration needs to be debated and discussed.

Developing a cost effective environmental solution for produced water and creating a ''new'' water resource

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doran, Glenn; Leong, Lawrence Y.C.

2000-05-01

The project goal is to convert a currently usable by-product of oil production, produced water, into a valuable drinking water resource. The project was located at the Placate Oil Field in Santa Clarita, California, approximately 25 miles north of Los Angeles. The project included a literature review of treatment technologies; preliminary bench-scale studies to refine a planning level cost estimate; and a 10-100 gpm pilot study to develop the conceptual design and cost estimate for a 44,000 bpd treatment facility. A reverse osmosis system was constructed, pilot tested, and the data used to develop a conceptual design and operation ofmore » four operational scenarios, two industrial waters levels and two irrigation/potable water.« less

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - PHYSICAL REMOVAL OF MICROBIOLOGICAL AND PARTICULATE CONTAMINANTS IN DRINKING WATER, HYDRANAUTICS HYDRACAP ULTRAFILTRATION MEMBRANE SYSTEM AT THE AQUA2000 RESEARCH CENTER - NSF 00/04/EPADW395

EPA Science Inventory

Verification testing of the Hydranautics HYDRA Cap(TM) Ultrafiltration Membrane System (Hydranautics UF unit) was conducted over two test periods at the Aqua 2000 Research Center in San Diego, CA. The first test period, from 8/3/99-9/13/99, represented summer/fall conditions. The...

ZENON ENVIRONMENTAL INC., ZENOGEM™ BIOLOGICAL AND ULTRAFILTRATION TECHNOLOGY; INNOVATIVE TECHNOLOGY EVALUATION REPORT

EPA Science Inventory

This report summarizes the results of a field demonstration conducted under the SITE Program. The technology which was demonstrated was a wastewater treatment technology developed by Zenon Environmental Inc. The process, named ZenoGem™, integrates biological treatment with memb...

A Short Review of Membrane Fouling in Forward Osmosis Processes

PubMed Central

Chun, Youngpil; Mulcahy, Dennis; Zou, Linda; Kim, In S.

2017-01-01

Interest in forward osmosis (FO) research has rapidly increased in the last decade due to problems of water and energy scarcity. FO processes have been used in many applications, including wastewater reclamation, desalination, energy production, fertigation, and food and pharmaceutical processing. However, the inherent disadvantages of FO, such as lower permeate water flux compared to pressure driven membrane processes, concentration polarisation (CP), reverse salt diffusion, the energy consumption of draw solution recovery and issues of membrane fouling have restricted its industrial applications. This paper focuses on the fouling phenomena of FO processes in different areas, including organic, inorganic and biological categories, for better understanding of this long-standing issue in membrane processes. Furthermore, membrane fouling monitoring and mitigation strategies are reviewed. PMID:28604649

RECOVERY OF MUTAGENICITY FROM DISINFECTED WATER SAMPLES BY XAD RESIN ADSORPTION COMPARED TO REVERSE OSMOSIS

EPA Science Inventory

the presence of a complex misture of disinfection byproducts in drinking waters continues to cause concern over the potential long-term health effects of exposure to these compounds. Most of these compounds are present at ug/L levels or less. Consequently, some method of concentr...

Integrated Disinfection Byproducts (DBPs) Mixtures Research: DBP Concentration via Reverse Osmosis Membrane Techniques

EPA Science Inventory

With the completion of the 4-lab project, the NOM concentration aspect of 4-lab is being continued with renewed focus on creating drinking water relevant freeze-dried NOM isolates that can be used for many drinking water research efforts from DBP investigations to water reuse inv...

Developmental Toxicity Evaluations of Whole Mixtures of Disinfection By-products using Concentrated Drinking Water in Rats: Gestational and Lactational Effects of Sulfate and Sodium

EPA Science Inventory

A developmental toxicity bioassay was used in three experiments to evaluate drinking water concentrates for suitability in multigenerational studies. First, chlorinated water was concentrated 135 fold by reverse osmosis; select lost disinfection by-products were spiked back. Co...

Developmental Toxicity Evaluations of Whole Mixtures of Disinfection By-products using Concentrated Drinking Water in Rats: Gestational and Lactational Effects of Sulfate and Sodium*

EPA Science Inventory

A developmental toxicity bioassay was used in three experiments to evaluate drinking water concentrates for suitability in multigenerational studies. First, chlorinated water was concentrated 135 fold by reverse osmosis; select lost disinfection by-products were spiked back. Conc...

ETV REPORT: REMOVAL OF CHEMICAL CONTAMINANTS IN DRINKING WATER – WATTS PREMIER INC. WP-4V DRINKING WATER TREATMENT SYSTEM

EPA Science Inventory

The Watts Premier WP-4V POU drinking water treatment system was tested for removal of aldicarb, benzene, cadmium, carbofuran, cesium, chloroform, dichlorvos, dicrotophos, fenamiphos, mercury, mevinphos, oxamyl, strontium, and strychnine. The WP-4V employs a reverse osmosis (RO) m...

75 FR 16080 - Notice of Intent To Prepare an Environmental Impact Statement for Basewide Water Infrastructure...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-31

...- design and to develop additional alternatives for analysis. These two water infrastructure projects are... carbon, and reverse osmosis. The facility would be designed in modular form for ease of expandability... lighting, asphalt pavement, and pavement marking and signs. The project includes ``100-year storm'' flood...

Treatment of Synthetic Urinous Wastewater Using Combined Reverse Osmosis, Immobilized Urease, and Ion Exchange Systems

DTIC Science & Technology

1974-09-01

invertase on DEAE-Cellulose while glucoamylase bound to the same carrier has been studied (Bachler et al., 1970; Gruesbeck and Rase, 1972). Adsorption of...Arch. Biochem. Biophys. 130, 384. Katchalski, E., Silman, I., and Goldstein, R. (1971) Adv. Enzymology 34., 445. Katz, S. A., and Cowans, J

21 CFR 177.2550 - Reverse osmosis membranes.

Code of Federal Regulations, 2011 CFR

2011-04-01

... is on the food-contact surface, and its maximum weight is 62 milligrams per square decimeter (4 milligrams per square inch) as a thin film composite on a suitable support. (2) A cross-linked polyetheramine... weight is 4.7 milligrams per square decimeter (0.3 milligrams per square inch) as a thin film composite...

21 CFR 177.2550 - Reverse osmosis membranes.

Code of Federal Regulations, 2013 CFR

2013-04-01

... is on the food-contact surface, and its maximum weight is 62 milligrams per square decimeter (4 milligrams per square inch) as a thin film composite on a suitable support. (2) A cross-linked polyetheramine... weight is 4.7 milligrams per square decimeter (0.3 milligrams per square inch) as a thin film composite...

21 CFR 177.2550 - Reverse osmosis membranes.

Code of Federal Regulations, 2010 CFR

2010-04-01

... is on the food-contact surface, and its maximum weight is 62 milligrams per square decimeter (4 milligrams per square inch) as a thin film composite on a suitable support. (2) A cross-linked polyetheramine... weight is 4.7 milligrams per square decimeter (0.3 milligrams per square inch) as a thin film composite...

21 CFR 177.2550 - Reverse osmosis membranes.

Code of Federal Regulations, 2012 CFR

2012-04-01

... is on the food-contact surface, and its maximum weight is 62 milligrams per square decimeter (4 milligrams per square inch) as a thin film composite on a suitable support. (2) A cross-linked polyetheramine... weight is 4.7 milligrams per square decimeter (0.3 milligrams per square inch) as a thin film composite...

Preparation of alpha-alumina-supported mesoporous bentonite membranes for reverse osmosis desalination of aqueous solutions.

PubMed

Li, Liangxiong; Dong, Junhang; Lee, Robert

2004-05-15

In this study, mesoporous bentonite clay membranes approximately 2 microm thick were prepared on porous alpha-alumina substrates by a sol-gel method. Nanosized clay particles were obtained from commercial Na-bentonite powders (Wyoming) by a process of sedimentation, washing, and freeze-drying. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption-desorption were employed for membrane characterization. It was found that the content of solids, concentration of polymer binder, and pH value of the clay colloidal suspension had critical influences on membrane formation during the dip-coating process. The membranes were tested for reverse osmosis separation of a 0.1 M NaCl solution. Both water permeability and Na(+) rejection rate of the supported membranes were comparable to those of the compacted thick membranes reported in the literature. However, due to the drastically reduced membrane thickness, water permeance and flux of the supported membranes were significantly higher than those of the compacted thick membranes. It was also observed that the calcination temperature played a critical role in determining structural stability in water and desalination performance of the clay membrane.

Theory of Ion and Water Transport in Reverse-Osmosis Membranes

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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

2014-08-15

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Assessing the integration of forward osmosis and anaerobic digestion for simultaneous wastewater treatment and resource recovery.

PubMed

Ansari, Ashley J; Hai, Faisal I; Price, William E; Ngo, Huu H; Guo, Wenshan; Nghiem, Long D

2018-07-01

This study assessed the performance and key challenges associated with the integration of forward osmosis (FO) and anaerobic digestion for wastewater treatment and resource recovery. Using a thin film composite polyamide FO membrane, maximising the pre-concentration factor (i.e. system water recovery) resulted in the enrichment of organics and salinity in wastewater. Biomethane potential evaluation indicated that methane production increased correspondingly with the FO pre-concentration factor due to the organic retention in the feed solution. At 90% water recovery, about 10% more methane was produced when using NaOAc compared with NaCl because of the contribution of biodegradable reverse NaOAc flux. No negative impact on anaerobic digestion was observed when wastewater was pre-concentrated ten-fold (90% water recovery) for both draw solutes. Interestingly, the unit cost of methane production using NaOAc was slightly lower than NaCl due to the lower reverse solute flux of NaOAc, although NaCl is a much cheaper chemical. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Treatment of vegetable oily wastewater using an integrated microfiltration-reverse osmosis system.

PubMed

Yu, Xiaoli; Zhong, Zhaoxiang; Xing, Weihong

2010-01-01

Vegetable oil processing plants and catering trade often generate a large amount of oil-containing wastewater, which causes serious environmental problems. The objective of this work was to explore the feasibility of vegetable oil wastewater treatment with an integrated microfiltration-reverse osmosis (MF-RO) process. The influence of operational parameters on the separation behaviors were investigated in MF process. In MF continuous process the steady flux was around 90 (L/m(2) h) when the concentrated multiple reached 16, and the oil content in permeate was less than 12 mg/L. In the RO continuous process, antifouling membrane was used to treat permeate from the ceramic membrane process in order to improve the water quality. The RO process had a permeate flux of 24 (L/m(2) h) and water recovery rate of 95%. The permeate from the RO stage was free of oil, and its TOC and conductivity were less than 0.6 mg/L and 50 micros/cm, respectively. The results demonstrated that the two stage membrane process combining MF and RO is highly efficient in the treatment of oil-containing wastewater.

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

PubMed

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.

Selected problems with boron determination in water treatment processes. Part I: comparison of the reference methods for ICP-MS and ICP-OES determinations.

PubMed

Kmiecik, Ewa; Tomaszewska, Barbara; Wątor, Katarzyna; Bodzek, Michał

2016-06-01

The aim of the study was to compare the two reference methods for the determination of boron in water samples and further assess the impact of the method of preparation of samples for analysis on the results obtained. Samples were collected during different desalination processes, ultrafiltration and the double reverse osmosis system, connected in series. From each point, samples were prepared in four different ways: the first was filtered (through a membrane filter of 0.45 μm) and acidified (using 1 mL ultrapure nitric acid for each 100 mL of samples) (FA), the second was unfiltered and not acidified (UFNA), the third was filtered but not acidified (FNA), and finally, the fourth was unfiltered but acidified (UFA). All samples were analysed using two analytical methods: inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES). The results obtained were compared and correlated, and the differences between them were studied. The results show that there are statistically significant differences between the concentrations obtained using the ICP-MS and ICP-OES techniques regardless of the methods of sampling preparation (sample filtration and preservation). Finally, both the ICP-MS and ICP-OES methods can be used for determination of the boron concentration in water. The differences in the boron concentrations obtained using these two methods can be caused by several high-level concentrations in selected whole-water digestates and some matrix effects. Higher concentrations of iron (from 1 to 20 mg/L) than chromium (0.02-1 mg/L) in the samples analysed can influence boron determination. When iron concentrations are high, we can observe the emission spectrum as a double joined and overlapping peak.

Water reuse: >90% water yield in MBR/RO through concentrate recycling and CO2 addition as scaling control.

PubMed

Joss, Adriano; Baenninger, Claudia; Foa, Paolo; Koepke, Stephan; Krauss, Martin; McArdell, Christa S; Rottermann, Karin; Wei, Yuansong; Zapata, Ana; Siegrist, Hansruedi

2011-11-15

Over 1.5 years continuous piloting of a municipal wastewater plant upgraded with a double membrane system (ca. 0.6 m(3) d(-1) of product water produced) have demonstrated the feasibility of achieving high water quality with a water yield of 90% by combining a membrane bioreactor (MBR) with a submerged ultrafiltration membrane followed by a reverse osmosis membrane (RO). The novelty of the proposed treatment scheme consists of the appropriate conditioning of MBR effluent prior to the RO and in recycling the RO concentrates back to the biological unit. All the 15 pharmaceuticals measured in the influent municipal sewage were retained below 100 ng L(-1), a proposed quality parameter, and mostly below detection limits of 10 ng L(-1). The mass balance of the micropollutants shows that these are either degraded or discharged with the excess concentrate, while only minor quantities were found in the excess sludge. The micropollutant load in the concentrate can be significantly reduced by ozonation. A low treated water salinity (<10 mM inorganic salts; 280 ± 70 μS cm(-1)) also confirms that the resulting product has a high water quality. Solids precipitation and inorganic scaling are effectively mitigated by lowering the pH in the RO feed water with CO(2) conditioning, while the concentrate from the RO is recycled to the biological unit where CO(2) is stripped by aeration. This causes precipitation to occur in the bioreactor bulk, where it is much less of a process issue. SiO(2) is the sole exception. Equilibrium modeling of precipitation reactions confirms the effectiveness of this scaling-mitigation approach for CaCO(3) precipitation, calcium phosphate and sulfate minerals. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

PubMed

Shang, Ran; Verliefde, Arne R D; Hu, Jingyi; Zeng, Zheyi; Lu, Jie; Kemperman, Antoine J B; Deng, Huiping; Nijmeijer, Kitty; Heijman, Sebastiaan G J; Rietveld, Luuk 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 potentially be adopted as an effective process for RO pre-treatment in order to constrain biofouling by phosphate limitation. This paper focuses on electrostatic interactions during tight UF filtration. Despite the larger pore size, the 3 kDa ceramic membrane exhibited greater phosphate rejection than the 1 kDa membrane, because the 3 kDa membrane has a greater negative surface charge and thus greater electrostatic repulsion against phosphate. The increase of pH from 6 to 8.5 led to a substantial increase in phosphate rejection by both membranes due to increased electrostatic repulsion. At pH 8.5, the maximum phosphate rejections achieved by the 1 kDa and 3 kDa membrane were 75% and 86%, respectively. A Debye ratio (ratio of the Debye length to the pore radius) is introduced in order to evaluate double layer overlapping in tight UF membranes. Threshold Debye ratios were determined as 2 and 1 for the 1 kDa and 3 kDa membranes, respectively. A Debye ratio below the threshold Debye ratio leads to dramatically decreased phosphate rejection by tight UF membranes. The phosphate rejection by the tight UF, in combination with chemical phosphate removal by coagulation, might accomplish phosphate-limited conditions for biological growth and thus prevent biofouling in the RO systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

Solar-Powered Desalination: A Modelling and Experimental Study

NASA Astrophysics Data System (ADS)

Leblanc, Jimmy; Andrews, John

2007-10-01

Water shortage is becoming one of the major problems worldwide. As such, desalination technologies have been implemented to meet growing demands for fresh water. Among the desalination technologies, thermal desalination, including multi stage flash (MSF) and multi effect evaporation (MEE), is the current leading desalination process. Reverse osmosis (RO) is also being increasingly used. Despite technological improvements, thermal desalination and reverse osmosis continue to be intensive fossil-fuel consumers and contribute to increased levels of greenhouse gases. As energy costs rise, thermal desalination by solar energy and/or low cost waste heat is likely to become increasingly attractive. As part of a project investigating the productive use of saline land and the development of sustainable desalination systems, the feasibility of producing potable water from seawater or brackish water using desalination systems powered by renewable energy in the form of low-temperature solar-thermal sources has been studied. A salinity-gradient solar pond and an evacuated tube solar collector system have been used as heat sources. Solar ponds combine solar energy collection with long-term storage and can provide reliable thermal energy at temperature ranges from 50 to 90 °C. A visual basic computer model of the different multi-stage flash desalination processes coupled with a salinity-gradient solar pond was developed to determine which process is preferable in regards to performance and greenhouse impact. The governing mathematical equations are derived from mass balances, heat energy balances, and heat transfer characteristics. Using the results from the modelling, a small-scale solar-powered desalination system, capable of producing up to 500 litres of fresh water per day, was designed and manufactured. This single-stage flash system consists of two main units: the heat supply and storage system and the flash desalination unit. Two different condenser heat exchanger materials were investigated: copper-nickel and a commercially available plastic. The modelling and design of a three effects MEE system is also discussed. The effects of the important design and operating parameters (recovery ratio, thermal energy, parasitic electrical energy, distillate production and solar collection area) controlling the cost of fresh water determined both from the computer simulation and experimental results are presented and analysed in this paper. Future work in the overall research program is also outlined.

Membrane Desalination: Where Are We, and What Can We Learn from Fundamentals?

PubMed

Imbrogno, Joseph; Belfort, Georges

2016-06-07

Although thermal desalination technology provides potable water in arid regions (e.g., Israel and the Gulf), its relatively high cost has limited application to less arid regions with large populations (e.g., California). Energy-intensive distillation is currently being replaced with less costly pressure- and electrically driven membrane-based processes. Reverse osmosis (RO) is a preferred membrane technology owing to process and pre- and posttreatment improvements that have significantly reduced energy requirements and cost. Further technical advances will require a deeper understanding of the fundamental science underlying RO. This includes determining the mechanism for water selectivity; elucidating the behavior of molecular water near polar and apolar surfaces, as well as the advantages and limitations of hydrophobic versus hydrophilic pores; learning the rules of selective water transport from nature; and designing synthetic analogs for selective water transport. Molecular dynamics simulations supporting experiments will play an important role in advancing these efforts. Finally, future improvements in RO are limited by inherent technical mass transfer limitations.

Alternative Water Processor Test Development

NASA Technical Reports Server (NTRS)

Pickering, Karen D.; Mitchell, Julie L.; Adam, Niklas M.; Barta, Daniel; Meyer, Caitlin E.; Pensinger, Stuart; Vega, Leticia M.; Callahan, Michael R.; Flynn, Michael; Wheeler, Ray;

Alternative Water Processor Test Development

NASA Technical Reports Server (NTRS)

Pickering, Karen D.; Mitchell, Julie; Vega, Leticia; Adam, Niklas; Flynn, Michael; Wjee (er. Rau); Lunn, Griffin; Jackson, Andrew

2012-01-01

The Next Generation Life Support Project is developing an Alternative Water Processor (AWP) as a candidate water recovery system for long duration exploration missions. The AWP consists of biological water processor (BWP) integrated with a forward osmosis secondary treatment system (FOST). The basis of the BWP is a membrane aerated biological reactor (MABR), developed in concert with Texas Tech University. Bacteria located within the MABR metabolize organic material in wastewater, converting approximately 90% of the total organic carbon to carbon dioxide. In addition, bacteria convert a portion of the ammonia-nitrogen present in the wastewater to nitrogen gas, through a combination of nitrogen and denitrification. The effluent from the BWP system is low in organic contaminants, but high in total dissolved solids. The FOST system, integrated downstream of the BWP, removes dissolved solids through a combination of concentration-driven forward osmosis and pressure driven reverse osmosis. The integrated system is expected to produce water with a total organic carbon less than 50 mg/l and dissolved solids that meet potable water requirements for spaceflight. This paper describes the test definition, the design of the BWP and FOST subsystems, and plans for integrated testing.

SWITCHABLE POLARITY SOLVENTS AS DRAW SOLUTES FOR FORWARD OSMOSIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frederick F. Stewart; Mark L. Stone; Aaron D. Wilson

2013-03-01

Switchable polarity solvents (SPS), mixtures of carbon dioxide, water, and tertiary amines, are presented as viable forward osmosis (FO) draw solutes allowing a novel SPS FO process. In this study substantial osmotic strengths of SPS are measured with freezing point osmometry and were demonstrated to induce competitive ?uxes at high salt concentrations on a laboratory-scale FO unit utilizing a ?at sheet cellulose triacetate (CTA) membrane. Under the experimental conditions the SPS degrades the CTA membrane; however experiments with polyamide reverse osmosis (RO) membranes display stability towards SPS. Once the draw is diluted the major fraction of the switchable polarity solventmore » can be mechanically separated from the puri?ed water after polar to nonpolar phase shift induced by introduction of 1 atm carbon dioxide to 1 atm of air or nitrogen with mild heating. Trace amounts of SPS can be removed from the separated water with RO in a process that avoids solution concentration polarization. The separated nonpolar phase can be regenerated to a full strength draw and recycled with the re-addition of 1 atm of carbon dioxide.« less

Evolution of phospholipid contents during the production of quark cheese from buttermilk.

PubMed

Ferreiro, T; Martínez, S; Gayoso, L; Rodríguez-Otero, J L

2016-06-01

We report the evolution of phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), phosphatidylserine (PS), and sphingomyelin (SM) contents during the production of quark cheese from buttermilk by successive ultrafiltration concentration, enrichment with cream, concurrent homogenization and pasteurization, fermentative coagulation, and separation of quark from whey by further ultrafiltration. Buttermilk is richer than milk itself in phospholipids that afford desirable functional and technological properties, and is widely used in dairy products. To investigate how phospholipid content is affected by end-product production processes such as ultrafiltration, homogenization, pasteurization or coagulation, we measured the phospholipids at several stages of each of 5 industrial-scale quark cheese production runs. In each run, 10,000L of buttermilk was concentrated to half volume by ultrafiltration, enriched with cream, homogenized, pasteurized, inoculated with lactic acid bacteria, incubated to coagulation, and once more concentrated to half volume by ultrafiltration. Phospholipid contents were determined by HPLC with evaporative light scattering detection in the starting buttermilk, concentrated buttermilk, ultrafiltrate, cream-enriched concentrated buttermilk (both before and after concurrent homogenization and pasteurization), coagulate, and quark, and also in the rinsings obtained when the ultrafiltration equipment was washed following initial concentration. The average phospholipid content of buttermilk was approximately 5 times that of milk, and the phospholipid content of buttermilk fat 26 to 29 times that of milk fat. Although phospholipids did not cross ultrafiltration membranes, significant losses occurred during ultrafiltration (due to retention on the membranes) and during the homogenization and pasteurization process. During coagulation, however, phospholipid content rose, presumably as a consequence of the proliferation of the inoculated lactic acid bacteria. In spite of these changes in total phospholipid content, the relative proportions of the phospholipids studied remain fairly stable throughout quark production (PE>PC>SM>PS>PI) and similar to those found in the milk of the region, except that SM content was lower than in milk. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

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

PubMed

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.

SITE TECHNOLOGY CAPSULE: ZENOGEM™ WASTEWATER TREATMENT PROCESS

EPA Science Inventory

Zenon Environmental System's ZenoGem™ Wastewater Treatment Process treats aqueous media contaminated with volatile/semi-volatile organic compounds. This technology combines aerobic biological treatment to remove biodegradable organic compounds with ultrafiltration to separate res...

Ultimate Osmosis Engineered by the Pore Geometry and Functionalization of Carbon Nanostructures

PubMed Central

Song, Zhigong; Xu, Zhiping

2015-01-01

Osmosis is the key process in establishing versatile functions of cellular systems and enabling clean-water harvesting technologies. Membranes with single-atom thickness not only hold great promises in approaching the ultimate limit of these functions, but also offer an ideal test-bed to explore the underlying physical mechanisms. In this work, we explore diffusive and osmotic transport of water and ions through carbon nanotube and porous graphene based membranes by performing molecular dynamics simulations. Our comparative study shows that the cylindrical confinement in carbon nanotubes offers much higher salt rejection at similar permeability in osmosis compared to porous graphene. Moreover, chemical functionalization of the pores modulates the membrane performance by its steric and electrostatic nature, especially at small-size pores due to the fact that the optimal transport is achieved by ordered water transport near pore edges. These findings lay the ground for the ultimate design of forward osmosis membranes with optimized performance trade-off, given the capability of nano-engineering nanostructures by their geometry and chemistry. PMID:26037602

Layer by Layer, Nano-particle "Only" Surface Modification of Filtration Membranes

NASA Astrophysics Data System (ADS)

Escobar-Ferrand, Luis

Layer by Layer (LbL) deposition using primarily inorganic silica nanoparticles is employed for the modification of polymeric micro and ultrafiltration (MF/UF) membranes to produce thin film composites (TFC) with potential nanofiltration (NF) and reverse osmosis (RO) capabilities.. A variety of porous substrate membranes with different membrane surface characteristics are employed, but exhibiting in common that wicking of water does not readily occur into the pore structure, including polycarbonate track etched (PCTE), polyethersulfone (PES) and sulfonated PES (SPEES) MF/UF membranes. Both spherical (cationic/anionic) and eccentric elongated (anionic) silica nanoparticles are deposited using conditions similar to those reported by Lee et al. Appropriate selection of the pH's for anionic and cationic particle deposition enables the construction of nanoparticle only layers 100--1200 nm in thickness atop the original membrane substrates. The surface layer thickness varies monotonically with the number of bilayers (anionic/cationic deposition cycles) as expected. The deposition process is optimized to eliminate drying induced cracking and to improve mechanical durability via thickness control and post-deposition hydro-thermal treatment. The hydrodynamic permeability of these TFC membranes is measured to evaluate their performance under typical NF operating conditions using dead-end permeation experiments and their performance compared quantitatively with realistic hydrodynamic models, with favorable results. For track etched polycarbonate MF substrates, surface modification causes a permeability reduction of approximately two orders of magnitude with respect to the bare substrates, to values comparable to those for typical commercial NF membranes. Good quantitative agreement with hydrodynamic models with no adjustable parameters was also established for this case, providing indirect confirmation that the LbL deposited surface layers are largely defect (crack) free. Imaging of our TFC membranes after permeation tests confirmed that no significant mechanical damage resulted, indicating integrity and robustness of the LbL deposited surface layers in typical applications. The selectivity of these novel TFC membranes was also tested using standard "rejection" tests normally used to characterize NF and RO membranes for their capabilities in typical applications, such as water softening or desalination. We report the dextran standards molecular weight "cut-off" (MWCO) using mixed dextrans from 1.5 to 500 KDa in dead-end stir cells, and the percentage of rejection of standard bivalent and monovalent salt solutions using steady cross flow permeation experiments. The results confirm rejection of at least 60% of even the smallest dextrans, an estimated dextran MWCO of 20 KDa, and rejection of 10% and 20% for monovalent (NaCl) and bivalent (MgSO4) salts, respectively, for all the TFC membranes studied, while the unmodified membranes showed no rejection capability at all. The work supports that nanoparticle based LbL surface modification of MF/UF membranes can produce filtration quality media for important water purification applications, such as nanofiltration (NF) softening processes, natural organic matter (NOM) elimination and possibly reverse osmosis (RO) desalination.

Forward osmosis for oily wastewater reclamation: Multi-charged oxalic acid complexes as draw solutes.

PubMed

Ge, Qingchun; Amy, Gary Lee; Chung, Tai-Shung

2017-10-01

Forward osmosis (FO) has demonstrated its merits in hybrid FO seawater desalination. However, FO may have a potential for other applications if suitable draw solutes are available. In this study, a series of novel draw solutes based on oxalic acid (OA)-transitional metal complexes are presented. Influential factors of FO performance have been systematically investigated by varying the transitional metals, cations of the complex draw solutes as well as the experimental conditions. Compared to NaCl and other recently synthesized draw solutes, the OA complexes show superior FO performance in terms of high water fluxes up to 27.5 and 89.1 LMH under the respective FO and PRO (pressure retarded osmosis) modes, both with negligible reverse solute fluxes. The features of octahedral geometry, abundant hydrophilic groups and ionic species are crucial for the OA complexes as appropriate draw solutes with satisfactory FO performance. Among the synthesized OA complexes, the ammonium salt of chromic complex (NH 4 -Cr-OA) outperforms others due to the presence of more ionic species in its complex system. NH 4 -Cr-OA also performs better than the typical NaCl draw solute in FO oily wastewater treatment with higher water recovery and negligible reverse fluxes. Dilute solutions of OA complexes have been reconcentrated through membrane distillation (MD) and reused to new round of FO processes. The OA complexes have demonstrated their suitability and superiority as a novel class of draw solutes for the FO process in this study. Copyright © 2017 Elsevier Ltd. All rights reserved.

Final Scientific/Technical Report for Program Title: Solar Powered Dewvaporation Desalination System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ranganathan, Shashidhar

Desalination technologies have been used increasingly throughout the world to produce the drinking water from the brackish ground and sea water for the past few decades. Among the commercially available desalination technologies, reverse osmosis (RO) and multi-stage flash distillation are the most widely used technologies globally. However, these technologies are difficult to be directly integrated with green energies without converting them to electricity. Dewvaporation, a desalination process, uses saturated steam as a carrier-gas to evaporate water from saline feeds and form pure condensate. It has the major technical benefit of reusing energy, released from vapor condensation, multiple times. The currentmore » proposal has been planned to address this issue. In Phase I, we have successfully demonstrated the feasibility of a new plasmonic nanoparticle based approach through fabrication and evaluation of a solar powered water vapor generation module. The water vapor generation module allows generation of high temperature plasmon on a fiber bundle end, where strong water and plasmon interaction occurs generating water vapor. Plasmon enhanced water evaporation has been realized on plasmonic nanoparticle immobilized substrate with an energy conversion efficiency of over 50%.« less

Use of Low-Temperature Geothermal Energy for Desalination in the Western United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turchi, Craig S.; Akar, Sertac; Cath, Tzahi

2015-11-01

This joint project between the National Renewable Energy Laboratory and the Colorado School of Mines has examined the potential of using low-temperature geothermal resources for desalination. The temperature range in question is not well suited for electricity generation, but can be used for direct heating. Accordingly, the best integration approaches use thermal desalination technologies such as multi-effect distillation (MED) or membrane distillation (MD), rather than electric-driven technologies such as reverse osmosis (RO). The examination of different desalination technologies led to the selection of MD for pairing with geothermal energy. MD operates at near-ambient pressure and temperatures less than 100°C withmore » hydrophobic membranes. The technology is modular like RO, but the equipment costs are lower. The thermal energy demands of MD are higher than MED, but this is offset by an ability to run at lower temperatures and a low capital cost. Consequently, a geothermal-MD system could offer a low capital cost and, if paired with low-cost geothermal energy, a low operating cost. The target product water cost is $1.0 to $1.5 per cubic meter depending on system capacity and the cost of thermal energy.« less

Water transport across biological membranes: Overton, water channels, and peritoneal dialysis.

PubMed

Devuyst, O

2010-01-01

Peritoneal dialysis involves diffusive and convective transports and osmosis through the highly vascularized peritoneal membrane. Several lines of evidence have demonstrated that the water channel aquaporin-1 (AQP1) corresponds to the ultrasmall pore predicted by the modelization of peritoneal transport. Proof-of-principle studies have shown that upregulation of the expression of AQP1 in peritoneal capillaries is reflected by increased water permeability and ultrafiltration, without affecting the osmotic gradient and the permeability for small solutes. Inversely, studies in Aqp1 mice have shown that haplo-insufficiency in AQP1 is reflected by significant attenuation of water transport. Recent studies have identified lead compounds that could act as agonists of aquaporins, as well as putative binding sites and potential mechanisms of gating the water channel. By modulating water transport, these pharmacological agents could have clinically relevant effects in targeting specific tissues or disease states. These studies on the peritoneal membrane also provide an experimental framework to investigate the role of water channels in the endothelium and various cell types.

Bench-Scale and Pilot-Scale Treatment Technologies for the ...

EPA Pesticide Factsheets

Coal mine water (CMW) is typically treated to remove suspended solids, acidity, and soluble metals, but high concentrations of total dissolved solids (TDS) have been reported to impact the environment at several CMW discharge points. Consequently, various states have established TDS wastewater regulations and the US EPA has proposed a benchmark conductivity limit to reduce TDS impacts in streams near mining sites. Traditional CMW treatment effectively removes some TDS components, but is not effective in removing major salt ions due to their higher solubility. This paper describes the basic principles, effectiveness, advantages and disadvantages of various TDS removal technologies (adsorption, bioremediation, capacitive deionization, desalination, electro-chemical ion exchange, electrocoagulation, electrodialysis, ion exchange, membrane filtration, precipitation, and reverse osmosis) that have at least been tested in bench- and pilot-scale experiments. Recent discussions about new regulations to include total dissolved solids TDS) limits would propel interest in the TDS removal technologies focused on coal mine water. TDS removal is not a new concept and has been developed using different technologies for a number of applications, but coal mine water has unique characteristics (depending on the site, mining process, and solid-water-oxygen interactions), which make it unlikely to have a single technology predominating over others. What are some novel technolog

GENE EXPRESSION ALTERATIONS OBSERVED IN PRIMARY CULTURED RAT HEPATOCYTES AFTER TREATMENT WITH CHLORINATED OR CHLORINATED AND OZONATED DRINKING WATER FROM EAST FORK LAKE, OHIO

EPA Science Inventory

Drinking water from East Fork Lake was spiked with iodide and bromide, disinfected with chlorine or ozone + chlorine, concentrated ~100-fold using reverse osmosis, and volatile disinfection by-products (DBPs) added back. Primary rat hepatocytes were exposed to full-strength, 1:10...

75 FR 77906 - Biweekly Notice; Applications and Amendments to Facility Operating Licenses Involving No...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-14

... level be raised to support SSF RC Makeup System operability. Thus, the SFP water level will not be..., but should note that the NRC's E-Filing system does not support unlisted software, and the NRC Meta... a reverse osmosis system during normal plant operation to remove silica from borated water storage...

78 FR 22563 - Biweekly Notice; Applications and Amendments to Facility Operating Licenses and Combined Licenses...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-16

...-Filing system does not support unlisted software, and the NRC Meta System Help Desk will not be able to... reverse osmosis system during normal plant operation to purify the water in the borated water storage... result of water returned from the RO System with lower boron concentration. Thus, no adverse effects from...

Airfoil-shaped micro-mixers for reducing fouling on membrane surfaces

DOEpatents

Ho, Clifford K; Altman, Susan J; Clem, Paul G; Hibbs, Michael; Cook, Adam W

2012-10-23

An array of airfoil-shaped micro-mixers that enhances fluid mixing within permeable membrane channels, such as used in reverse-osmosis filtration units, while minimizing additional pressure drop. The enhanced mixing reduces fouling of the membrane surfaces. The airfoil-shaped micro-mixer can also be coated with or comprised of biofouling-resistant (biocidal/germicidal) ingredients.

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

EPA Science Inventory

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

Integrated Disinfection By-Products Mixtures Research: Concentration by Reverse Osmosis Membrane Techniques of Disinfection By-Products from Water Disinfected by Chlorination and Ozonation/Postchlorination

EPA Science Inventory

To conduct the health-effect studies described in subsequent articles in this series, concentrated aqueous mixtures of disinfection by-products were required for the two water treatment trains described in the preceding article (Miltner et al., 2008). To accomplish this, the fini...

Water Supply and Treatment Equipment. Change Notice 1

DTIC Science & Technology

2014-08-05

Coagulation Filtration Total Dissolved Solids Water Quality Conductivity Potable water Turbidity Water Treatment/Purification Disinfection ...microorganisms (pathogenic) found in the raw water . The preferred Army field method of water disinfection is chlorination. Filtration Filtration...senses. It looks, tastes, and smells good and is neither too hot nor too cold. Potable water Water that is safe for drinking . Reverse osmosis

Desalination: Status and Federal Issues

DTIC Science & Technology

2009-12-30

on one side and lets purified water through. Reverse osmosis plants have fewer problems with corrosion and usually have lower energy requirements...Texas) and cities are actively researching and investigating the feasibility of large-scale desalination plants for municipal water supplies...desalination research and development, and in construction and operational costs of desalination demonstration projects and full-scale plants

A Low Cost Environmentally Benign Waste Lubricants Recycling/Re-refining Technology.

DTIC Science & Technology

1999-05-01

EXPERIMENTAL 3 2.1 Ceramic Membrane Ultrafiltration Pilot Unit 3 2.2 Polishing/Finishing Pilot Unit 3 2.3 Feed Samples 3 2.4 Sample...development of an additional 2 to 3 sites in the US. 2. EXPERIMENTAL 2.1. Ceramic Membrane Ultrafiltration Pilot Unit A photograph of the pilot...scale ceramic membrane system used in this work is shown in Figure la. Samples of spent turbine oil were charged to the feed tank and heated to 150°C

Evaluation of Membrane Ultrafiltration and Residual Chlorination as a Decentralized Water Treatment Strategy for Ten Rural Healthcare Facilities in Rwanda

PubMed Central

Huttinger, Alexandra; Dreibelbis, Robert; Roha, Kristin; Ngabo, Fidel; Kayigamba, Felix; Mfura, Leodomir; Moe, Christine

2015-01-01

There is a critical need for safe water in healthcare facilities (HCF) in low-income countries. HCF rely on water supplies that may require additional on-site treatment, and need sustainable technologies that can deliver sufficient quantities of water. Water treatment systems (WTS) that utilize ultrafiltration membranes for water treatment can be a useful technology in low-income countries, but studies have not systematically examined the feasibility of this technology in low-income settings. We monitored 22 months of operation of 10 WTS, including pre-filtration, membrane ultrafiltration, and chlorine residual disinfection that were donated to and operated by rural HCF in Rwanda. The systems were fully operational for 74% of the observation period. The most frequent reasons for interruption were water shortage (8%) and failure of the chlorination mechanism (7%). When systems were operational, 98% of water samples collected from the HCF taps met World Health Organization (WHO) guidelines for microbiological water quality. Water quality deteriorated during treatment interruptions and when water was stored in containers. Sustained performance of the systems depended primarily on organizational factors: the ability of the HCF technician to perform routine servicing and repairs, and environmental factors: water and power availability and procurement of materials, including chlorine and replacement parts in Rwanda. PMID:26516883

Evaluation of Membrane Ultrafiltration and Residual Chlorination as a Decentralized Water Treatment Strategy for Ten Rural Healthcare Facilities in Rwanda.

PubMed

Huttinger, Alexandra; Dreibelbis, Robert; Roha, Kristin; Ngabo, Fidel; Kayigamba, Felix; Mfura, Leodomir; Moe, Christine

2015-10-27

There is a critical need for safe water in healthcare facilities (HCF) in low-income countries. HCF rely on water supplies that may require additional on-site treatment, and need sustainable technologies that can deliver sufficient quantities of water. Water treatment systems (WTS) that utilize ultrafiltration membranes for water treatment can be a useful technology in low-income countries, but studies have not systematically examined the feasibility of this technology in low-income settings. We monitored 22 months of operation of 10 WTS, including pre-filtration, membrane ultrafiltration, and chlorine residual disinfection that were donated to and operated by rural HCF in Rwanda. The systems were fully operational for 74% of the observation period. The most frequent reasons for interruption were water shortage (8%) and failure of the chlorination mechanism (7%). When systems were operational, 98% of water samples collected from the HCF taps met World Health Organization (WHO) guidelines for microbiological water quality. Water quality deteriorated during treatment interruptions and when water was stored in containers. Sustained performance of the systems depended primarily on organizational factors: the ability of the HCF technician to perform routine servicing and repairs, and environmental factors: water and power availability and procurement of materials, including chlorine and replacement parts in Rwanda.

Review of Water Resources and Desalination Technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

MILLER, JAMES E.

Water shortages affect 88 developing countries that are home to half of the world's population. In these places, 80-90% of all diseases and 30% of all deaths result from poor water quality. Furthermore, over the next 25 years, the number of people affected by severe water shortages is expected to increase fourfold. Low cost methods to desalinate brackish water and sea water can help reverse this destabilizing trend. Desalination has now been practiced on a large scale for more than 50 years. During this time continual improvements have been made, and the major technologies are now remarkably efficient, reliable, andmore » inexpensive. For many years, thermal technologies were the only viable option, and multi-stage flash (MSF) was established as the baseline technology. Multi-effect evaporation (MEE) is now the state-of-the-art thermal technology, but has not been widely implemented. With the growth of membrane science, reverse osmosis (RO) overtook MSF as the leading desalination technology, and should be considered the baseline technology. Presently, RO of seawater can be accomplished with an energy expenditure in the range of 11-60 kJ/kg at a cost of $2 to $4 per 1000 gallons. The theoretical minimum energy expenditure is 3-7 kJ/kg. Since RO is a fairly mature technology, further improvements are likely to be incremental in nature, unless design improvements allow major savings in capital costs. Therefore, the best hope to dramatically decrease desalination costs is to develop ''out of the box'' technologies. These ''out of the box'' approaches must offer a significant advantage over RO (or MEE, if waste heat is available) if they are to be viable. When making these comparisons, it is crucial that the specifics of the calculation are understood so that the comparison is made on a fair and equivalent basis.« less

Silica extraction from geothermal water

DOEpatents

Bourcier, William L; Bruton, Carol J

2014-09-23

A method of producing silica from geothermal fluid containing low concentration of the silica of less than 275 ppm includes the steps of treating the geothermal fluid containing the silica by reverse osmosis treatment thereby producing a concentrated fluid containing the silica, seasoning the concentrated fluid thereby producing a slurry having precipitated colloids containing the silica, and separating the silica from the slurry.

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

PubMed Central

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

Design of stand-alone brackish water desalination wind energy system for Jordan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habali, S.M.; Saleh, I.A.

1994-06-01

More than 100 underground water wells drilled in Jordan are known to have brackish water with total desolved solids (TDS) over 1500 ppm but not greater than 4000 ppm. The world standard for potable water limits the TDS count to 500 ppm in addition to being free from live microorganisms or dangerous mineral and organic substances. A reverse osmosis desalination scheme powered by a stand-alone wind energy converter (WEC) is proposed to produce fresh water water from wells located in potentially high-wind sites. The purpose of this study if to present the main design parameters and economic estimates of amore » wind-assisted RO system using a diesel engine as the baseline energy source and an electric wind turbine for the wind energy source. It is found that brackish water pumping and desalinating using WECs costs 0.67 to 1.16 JD/m[sup 3] (JD = Jordanian Dinar, 1US$ = 0.68 JD), which is less than using conventional diesel engines especially in remote areas. In addition, the wind-reverse osmosis system becomes more economically feasible for higher annual production rates or in good wind regimes.« less

Improved calcium sulfate recovery from a reverse osmosis retentate using eutectic freeze crystallization.

PubMed

Randall, D G; Mohamed, R; Nathoo, J; Rossenrode, H; Lewis, A E

2013-01-01

A novel low temperature crystallization process called eutectic freeze crystallization (EFC) can produce both salt(s) and ice from a reverse osmosis (RO) stream by operating at the eutectic temperature of a solution. The EFC reject stream, which is de-supersaturated with respect to the scaling component, can subsequently be recycled back to the RO process for increased water recovery. This paper looks at the feasibility of using EFC to remove calcium sulfate from an RO retentate stream and compares the results to recovery rates at 0 and 20 °C. The results showed that there was a greater yield of calcium sulfate obtained at 0 °C as compared with 20 °C. Operation under eutectic conditions, with only a 20% ice recovery, resulted in an even greater yield of calcium sulfate (48%) when compared with yields obtained at operating temperatures of 0 and 20 °C (15% at 0 °C and 13% at 20 °C). The theoretical calcium recoveries were found to be 75 and 70% at 0 and 20 °C respectively which was higher than the experimentally determined values. The EFC process has the added advantage of producing water along with a salt.

Ozone and biofiltration as an alternative to reverse osmosis for removing PPCPs and micropollutants from treated wastewater.

PubMed

Lee, Carson O; Howe, Kerry J; Thomson, Bruce M

2012-03-15

This pilot-scale research project investigated and compared the removal of pharmaceuticals and personal care products (PPCPs) and other micropollutants from treated wastewater by ozone/biofiltration and reverse osmosis (RO). The reduction in UV254 absorbance as a function of ozone dose correlated well with the reduction in nonbiodegradable dissolved organic carbon and simultaneous production of biodegradable dissolved organic carbon (BDOC). BDOC analyses demonstrated that ozone does not mineralize organics in treated wastewater and that biofiltration can remove the organic oxidation products of ozonation. Biofiltration is recommended for treatment of ozone contactor effluent to minimize the presence of unknown micropollutant oxidation products in the treated water. Ozone/biofiltration and RO were compared on the basis of micropollutant removal efficiency, energy consumption, and waste production. Ozone doses of 4-8 mg/L were nearly as effective as RO for removing micropollutants. When wider environmental impacts such as energy consumption, water recovery, and waste production are considered, ozone/biofiltration may be a more desirable process than RO for removing PPCPs and other trace organics from treated wastewater. Copyright © 2011 Elsevier Ltd. All rights reserved.

Evaluating a strategy for maintaining nitrifier activity during long-term starvation in a moving bed biofilm reactor (MBBR) treating reverse osmosis concentrate.

PubMed

Ye, Liu; Hu, Shihu; Poussade, Yvan; Keller, Jurg; Yuan, Zhiguo

2012-01-01

A two-stage moving bed biofilm reactor (MBBR) was applied at the Bundamba advanced water treatment plant (AWTP) (Queensland, Australia) to treat the reverse osmosis concentrate (ROC) for inorganic nutrient removal. One of the operational challenges for the system was to cope with the large fluctuations of the ROC flow. This study investigated the decay rates of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) and biofilm detachment in MBBR during starvation for up to one month. An intermittent aeration strategy of 15 min aeration every 6 h was applied. This study also evaluated the activity recovery of both AOB and NOB after normal operation was resumed. The results showed that the activity loss of AOB and NOB was relatively minor (<20%) within 10 days of starvation, which ensured relatively quick recovery of ammonium removal when normal operation resumed. In contrast, the AOB and NOB activity loss reached 60-80% when the starvation time was longer than 20 days, resulting in slower recovery of ammonium removal after starvation. Starvation for less than 20 days didn't result in an apparent biomass detachment from carriers.

Saline Groundwater from Coastal Aquifers As a Source for Desalination.

PubMed

Stein, Shaked; Russak, Amos; Sivan, Orit; Yechieli, Yoseph; Rahav, Eyal; Oren, Yoram; Kasher, Roni

2016-02-16

Reverse osmosis (RO) seawater desalination is currently a widespread means of closing the gap between supply and demand for potable water in arid regions. Currently, one of the main setbacks of RO operation is fouling, which hinders membrane performance and induces pressure loss, thereby reducing system efficiency. An alternative water source is saline groundwater with salinity close to seawater, pumped from beach wells in coastal aquifers which penetrate beneath the freshwater-seawater interface. In this research, we studied the potential use of saline groundwater of the coastal aquifer as feedwater for desalination in comparison to seawater using fieldwork and laboratory approaches. The chemistry, microbiology and physical properties of saline groundwater were characterized and compared with seawater. Additionally, reverse osmosis desalination experiments in a cross-flow system were performed, evaluating the permeate flux, salt rejection and fouling propensities of the different water types. Our results indicated that saline groundwater was significantly favored over seawater as a feed source in terms of chemical composition, microorganism content, silt density, and fouling potential, and exhibited better desalination performance with less flux decline. Saline groundwater may be a better water source for desalination by RO due to lower fouling potential, and reduced pretreatment costs.

Reverse osmosis desalination of chitosan cross-linked graphene oxide/titania hybrid lamellar membranes.

PubMed

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.

High rejection reverse osmosis membrane for removal of N-nitrosamines and their precursors.

PubMed

Fujioka, Takahiro; Ishida, Kenneth P; Shintani, Takuji; Kodamatani, Hitoshi

2017-12-12

Direct potable reuse is becoming a feasible option to cope with water shortages. It requires more stringent water quality assurance than indirect potable reuse. Thus, the development of a high-rejection reverse osmosis (RO) membrane for the removal of one of the most challenging chemicals in potable reuse - N-nitrosodimethylamine (NDMA) - ensures further system confidence in reclaimed water quality. This study aimed to achieve over 90% removal of NDMA by modifying three commercial and one prototype RO membrane using heat treatment. Application of heat treatment to a prototype membrane resulted in a record high removal of 92% (1.1-log) of NDMA. Heat treatment reduced conductivity rejection and permeability, while secondary amines, selected as N-nitrosamine precursors, were still well rejected (>98%) regardless of RO membrane type. This study also demonstrated the highly stable separation performance of the heat-treated prototype membrane under conditions of varying feed temperature and permeate flux. Fouling propensity of the prototype membrane was lower than a commercial RO membrane. This study identified a need to develop highly selective RO membranes with high permeability to ensure the feasibility of using these membranes at full scale. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

PubMed

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

2016-01-25

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

Is ozonation environmentally benign for reverse osmosis concentrate treatment? Four-level analysis on toxicity reduction based on organic matter fractionation.

PubMed

Weng, Jingxia; Jia, Huichao; Wu, Bing; Pan, Bingcai

2018-01-01

Ozonation is a promising option to treat reverse osmosis concentrate (ROC). However, a systematic understanding and assessment of ozonation on toxicity reduction is insufficient. In this study, ROC sampled from a typical industrial park wastewater treatment plant of China was fractionated into hydrophobic acid (HOA), hydrophobic base (HOB), hydrophobic neutral (HON), and hydrophilic fraction (HI). Systematic bioassays covering bacteria, algae, fish, and human cell lines were conducted to reveal the role of ozonation in toxicity variation of the four ROC fractions. HOA in the raw ROC exhibited the highest toxicity, followed by HON and HI. Ozonation significantly reduced total organic carbon (TOC) and UV 254 values in HOA, HON, and HI and their toxicity except in HOB. Correlation analysis indicated that chemical data (TOC and UV 254 ) of HOA and HON correlated well with their toxicities; however, poor correlations were observed for HOB and HI, suggesting that a battery of toxicity assays is necessary. This study indicates that TOC reduction during ozonation could not fully reflect the toxicity issue, and toxicity assessment is required in conjunction with the chemical data to evaluate the effectiveness of ozonation. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

PubMed

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 (<88%) when conducted in pH values higher than 1. Thus, sequential use of NF and RO was proved to be a promising treatment for sulfuric 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.

Interactions of Organics within Hydrated Selective Layer of Reverse Osmosis Desalination Membrane: A Combined Experimental and Computational Study.

PubMed

Ghoufi, Aziz; Dražević, Emil; Szymczyk, Anthony

2017-03-07

In this work we have examined a computational approach in predicting the interactions between uncharged organic solutes and polyamide membranes. We used three model organic molecules with identical molecular weights (100.1 g/mol), 4-aminopiperidine, 3,3-dimethyl-2-butanone (pinacolone) and methylisobutyl ketone for which we obtained experimental data on partitioning, diffusion and separation on a typical seawater reverse osmosis (RO) membrane. The interaction energy between the solutes and the membrane phase (fully aromatic polyamide) was computed from molecular dynamics (MD) simulations and the resulting sequence was found to correlate well with the experimental rejections and sorption data. Sorption of the different organic solutes within the membrane skin layer determined from attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) nicely agreed with interaction energies computed from molecular simulations. Qualitative information about solute diffusivity inside the membrane was also extracted from MD simulations while ATR-FTIR experiments indicated strongly hindered diffusion with diffusion coefficients in the membrane about 10 -15 m 2 /s. The computational approach presented here could be a first step toward predicting rejections trends of, for example, hormones and pharmaceuticals by RO dense membranes.

Electrochemical oxidation of tramadol in low-salinity reverse osmosis concentrates using boron-doped diamond anodes.

PubMed

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.

Selective passive adsorption of nitrate with surfactant treated porous electrode and electrostatic regeneration

NASA Astrophysics Data System (ADS)

Oyarzun, Diego I.; Hemmatifar, Ali; Palko, James W.; Stadermann, Michael; Santiago, Juan G.; Stanford microfluidics lab Team; Lawrence Livermore National Lab Team

2017-11-01

Nitrate is an important pollutant in drinking water worldwide, and a number of methods exist for the removal of nitrate from water including ion exchange and reverse osmosis. However, these approaches suffer from a variety of disadvantages including the need for a regenerating brine supply and disposal of used brine for ion exchange and low water recovery ratio for reverse osmosis. We are researching and developing a form of capacitive deionization (CDI) for energy efficient desalination and selective removal of ionic toxins from water. In CDI an electrode is used to electrostatically trap ions in a pair of porous electrodes. Here, we demonstrate the use of high surface area activated carbon electrodes functionalized with ion exchange moieties for adsorption of nitrate from aqueous solution. Unlike a traditional ion exchanger, the functionalized surfaces can be repeatedly regenerated by the application of an electrostatic potential which displaces the bound NO3- while leaving an excess of electronic charge on the electrode. Trimethylammonium has an intrinsic selectivity, we are using this moiety to selectively remove nitrate over chloride. We performed adsorption/desorption cycles under several desorption voltages and ratios of concentrations.

Removal of nitrogen compounds from landfill leachate using reverse osmosis with leachate stabilization in a buffer tank.

PubMed

Talalaj, Izabela Anna

2015-01-01

In this paper, a removal of nitrogen compounds from a landfill leachate during reverse osmosis (RO) was evaluated. The treatment facility consists of a buffer tank and a RO system. The removal rate of N─NH4, [Formula: see text] and [Formula: see text] in the buffer tank reached 14%, 91% and 41%, respectively. The relatively low concentration of organic carbon limits N─NH4 oxidation in the buffer tank. The removal rate for the total organic nitrogen (TON) was 47%. The removal rate in RO was 99% for [Formula: see text], 84.1% for [Formula: see text] and 41% for [Formula: see text]. The accumulation of [Formula: see text] may be the result of a low pH, which before the RO process is reduced to a value of 6.0-6.5. Besides it, the cause for a low removal rate of the [Formula: see text] in the buffer tank and during RO may be free ammonia, which can inhibit the [Formula: see text] oxidation. The removal rates of total inorganic nitrogen and TON in the RO treatment facility were similar being 99% and 98.5%, respectively.

A novel reverse osmosis membrane by ferrous sulfate assisted controlled oxidation of polyamide layer

NASA Astrophysics Data System (ADS)

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.

Membrane morphology and topology for fouling control in Reverse Osmosis filtration systems

NASA Astrophysics Data System (ADS)

Ling, Bowen; Battiato, Ilenia

2017-11-01

Reverse Osmosis Membrane (ROM) filtration systems are widely utilized in waste-water recovery, seawater desalination, landfill water treatment, etc. During filtration, the system performance is dramatically affected by membrane fouling which causes a significant decrease in permeate flux as well as an increase in the energy input required to operate the system. Design and optimization of ROM filtration systems aim at reducing membrane fouling by studying the coupling between membrane structure, local flow field and foulant adsorption patterns. Yet, current studies focus exclusively on oversimplified steady-state models that ignore any dynamic coupling between fluid flow and transport through the membrane. In this work, we develop a customized solver (SUMembraneFoam) under OpenFOAM to solve the transient equations. The simulation results not only predict macroscopic quantities (e.g. permeate flux, pressure drop, etc.) but also show an excellent agreement with the fouling patterns observed in experiments. It is observed that foulant deposition is strongly controlled by the local shear stress on the membrane, and channel morphology or membrane topology can be modified to control the shear stress distribution and reduce fouling. Finally, we identify optimal regimes for design.

Molecular cloning of Brevundimonas diminuta for efficacy assessment of reverse osmosis devices.

PubMed

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.

Reverse osmosis followed by activated carbon filtration for efficient removal of organic micropollutants from river bank filtrate.

PubMed

Kegel, F Schoonenberg; Rietman, B M; Verliefde, A R D

2010-01-01

Drinking water utilities in Europe are faced with a growing presence of organic micropollutants in their water sources. The aim of this research was to assess the robustness of a drinking water treatment plant equipped with reverse osmosis and subsequent activated carbon filtration for the removal of these pollutants. The total removal efficiency of 47 organic micropollutants was investigated. Results indicated that removal of most organic micropollutants was high for all membranes tested. Some selected micropollutants were less efficiently removed (e.g. the small and polar NDMA and glyphosate, and the more hydrophobic ethylbenzene and napthalene). Very high removal efficiencies for almost all organic micropollutants by the subsequent activated carbon, fed with the permeate stream of the RO element were observed except for the very small and polar NDMA and 1,4-dioxane. RO and subsequent activated carbon filtration are complementary and their combined application results in the removal of a large part of these emerging organic micropollutants. Based on these experiments it can be concluded that the robustness of a proposed treatment scheme for the drinking water treatment plant Engelse Werk is sufficiently guaranteed.

Fabrication of hydrophobic fluorinated silica-polyamide thin film nanocomposite reverse osmosis membranes with dramatically improved salt rejection.

PubMed

Pang, Ruizhi; Zhang, Kaisong

2018-01-15

Thin film nanocomposite reverse osmosis (TFN RO) membranes incorporated with hydrophilic nanoparticles show a potential problem that the salt rejection can not be improved significantly. In this study, novel TFN RO membranes incorporated with hydrophobic fluorinated silica nanoparticles were fabricated to improve the salt rejection. Fluorinated silica nanoparticles were well dispersed in organic phase during the interfacial polymerization (IP) process. The TFN RO membranes were characterized with attenuated total reflectance infra-red, field emission scanning electron microscopy, atomic force microscopy and water contact angle measurements. The preparation conditions of TFN RO membranes, including IP reaction time, organic solvent removal time, and fluorinated silica loading, were optimized by characterizing desalination performance using 2000ppm NaCl aqueous solution at 1.55MPa and 25°C. The salt rejection increased significantly from 96.0% without fluorinated silica nanoparticles to 98.6% with the optimal 0.12% (w/v) fluorinated silica nanoparticles, while the water flux decreased slightly from 0.99m 3 /m 2 /day to 0.93m 3 /m 2 /day. This study demonstrated the potential use of hydrophobic nanoparticles in high-performance TFN RO membranes. Copyright © 2017 Elsevier Inc. All rights reserved.

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

PubMed

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%).

The Fresenius Medical Care home hemodialysis system.

PubMed

Schlaeper, Christian; Diaz-Buxo, Jose A

2004-01-01

The Fresenius Medical Care home dialysis system consists of a newly designed machine, a central monitoring system, a state-of-the-art reverse osmosis module, ultrapure water, and all the services associated with a successful implementation. The 2008K@home hemodialysis machine has the flexibility to accommodate the changing needs of the home hemodialysis patient and is well suited to deliver short daily or prolonged nocturnal dialysis using a broad range of dialysate flows and concentrates. The intuitive design, large graphic illustrations, and step-by-step tutorial make this equipment very user friendly. Patient safety is assured by the use of hydraulic systems with a long history of reliability, smart alarm algorithms, and advanced electronic monitoring. To further patient comfort with their safety at home, the 2008K@home is enabled to communicate with the newly designed iCare remote monitoring system. The Aquaboss Smart reverse osmosis (RO) system is compact, quiet, highly efficient, and offers an improved hygienic design. The RO module reduces water consumption by monitoring the water flow of the dialysis system and adjusting water production accordingly. The Diasafe Plus filter provides ultrapure water, known for its long-term benefits. This comprehensive approach includes planning, installation, technical and clinical support, and customer service.

MODIFIED REVERSE OSMOSIS SYSTEM FOR TREATMENT OF PRODUCED WATERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robert L. Lee; Junghan Dong

2004-06-03

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

Assessment of hydrogeologic conditions with emphasis on water quality and wastewater injection, southwest Sarasota and West Charlotte counties, Florida

USGS Publications Warehouse

Hutchinson, C.B.

1992-01-01

The 250-square-mile area of southwest Sarasota and west Charlotte Counties is underlain by a complex hydrogeologic system having diverse ground-water quality. The surficial and intermediate aquifer systems and the Upper Floridan aquifer of the Floridan aquifer system contain six separate aquifers, or permeable zones, and have a total thickness of about 2,000 feet. Water in the clastic surficial aquifer system is potable and is tapped by hundreds of shallow, low-yielding supply wells. Water in the mixed clastic and carbonate intermediate aquifer system is potable in the upper part, but in the lower part, because of increasing salinity, it is used primarily for reverse-osmosis desalinization feed water and irrigation. Within the Upper Floridan aquifer, limestone and dolomite of the Suwannee permeable zone are tapped by irrigation and reverse-osmosis supply wells. The underlying, less permeable limestone of the Suwannee-Ocala semiconfining unit generally encompasses the transition zone between freshwater and very saline water. Interbedded limestone and dolomite of the Ocala-Avon Park moderately permeable zone and Avon Park highly permeable zone compose the deep, very saline injection zone. Potential ground-water contamination problems include flooding by storm tides, upward movement of saline water toward pumping centers by natural and induced leakage or through improperly constructed and abandoned wells, and lateral and vertical movement of treated sewage and reverse-osmosis wastewater injected into deep zones. Effects of flooding are evident in coastal areas where vertical layering of fresh and saline waters is observed. Approximately 100 uncontrolled flowing artesian wells that have interaquifer flow rates as high as 350 gallons per minute have been located and scheduled for plugging by the Southwest Florida Water Management District--in an attempt to improve ground-water quality of the shallow aquifers. Because each aquifer or permeable zone has unique head and water-quality characteristics, construction of single-zone wells would eliminate cross-contamination and borehole interflow. Such a program, when combined with the plugging of shallow-cased wells having long open-hole intervals connecting multiple zones, would safeguard ground-water resources in the study area. The study area encompasses seven wastewater injection sites that have a projected capacity for injecting 29 million gallons per day into the zone 1,100 to 2,050 feet below land surface. There are six additional sites within 20 miles. The first well began injecting reverse-osmosis wastewater in 1984, and since then, other wells have been drilled and permitted for injection of treated sewage. A numerical model was used to evaluate injection-well design and potential for movement of injected wastewater within the hydrogeologic framework. The numerical model was used to simulate injection through a representative well at a rate of 1 million gallons per day for 10 years. In this simulation, a convection cell developed around the injection well with the buoyant fresh injectant rising to form a lens within the injection zone below the lower Suwannee-Ocala semiconfining unit. Around an ideal, fully penetrating well cased 50 feet into the injection zone and open from a depth of 1,150 feet to 2,050 feet, simulations show that the injectant moves upward to a depth of 940 feet, forms a lens about 600 feet thick, and spreads radially outward to a distance of about 2,300 feet after 10 years. Comparison simulations of injection through wells having open depth intervals of 1,150 to 1,400 feet and 1,450 to 2,050 feet demonstrate that such changes in well construction have little effect on the areal spread of the injectant lens or the rate of upward movement. Simulations also indicate that reverse-osmosis wastewater injected beneath a supply well field, where water levels above the semiconfining unit are lowered 20 feet by pumping, would move upward after 10 years to a de

An arduino based control system for a brackish water desalination plant

NASA Astrophysics Data System (ADS)

Caraballo, Ginna

Water scarcity for agriculture is one of the most important challenges to improve food security worldwide. In this thesis we study the potential to develop a low-cost controller for a small scale brackish desalination plant that consists of proven water treatment technologies, reverse osmosis, cation exchange, and nanofiltration to treat groundwater into two final products: drinking water and irrigation water. The plant is powered by a combination of wind and solar power systems. The low-cost controller uses Arduino Mega, and Arduino DUE, which consist of ATmega2560 and Atmel SAM3X8E ARM Cortex-M3 CPU microcontrollers. These are widely used systems characterized for good performance and low cost. However, Arduino also requires drivers and interfaces to allow the control and monitoring of sensors and actuators. The thesis explains the process, as well as the hardware and software implemented.

Whey cheese: membrane technology to increase yields.

PubMed

Riera, Francisco; González, Pablo; Muro, Claudia

2016-02-01

Sweet cheese whey has been used to obtain whey cheese without the addition of milk. Pre-treated whey was concentrated by nanofiltration (NF) at different concentration ratios (2, 2.5 and 2.8) or by reverse osmosis (RO) (2-3 times). After the concentration, whey was acidified with lactic acid until a final pH of 4.6-4.8, and heated to temperatures between 85 and 90 °C. The coagulated fraction (supernatant) was collected and freely drained over 4 h. The cheese-whey yield and protein, fat, lactose and ash recoveries in the final product were calculated. The membrane pre-concentration step caused an increase in the whey-cheese yield. The final composition of products was compared with traditional cheese-whey manufacture products (without membrane concentration). Final cheese yields found were to be between 5 and 19.6%, which are higher than those achieved using the traditional 'Requesón' process.

Declassification of radioactive water from a pool type reactor after nuclear facility dismantling

NASA Astrophysics Data System (ADS)

Arnal, J. M.; Sancho, M.; García-Fayos, B.; Verdú, G.; Serrano, C.; Ruiz-Martínez, J. T.

2017-09-01

This work is aimed to the treatment of the radioactive water from a dismantled nuclear facility with an experimental pool type reactor. The main objective of the treatment is to declassify the maximum volume of water and thus decrease the volume of radioactive liquid waste to be managed. In a preliminary stage, simulation of treatment by the combination of reverse osmosis (RO) and evaporation have been performed. Predicted results showed that the combination of membrane and evaporation technologies would result in a volume reduction factor higher than 600. The estimated time to complete the treatment was around 650 h (25-30 days). For different economical and organizational reasons which are explained in this paper, the final treatment of the real waste had to be reduced and only evaporation was applied. The volume reduction factor achieved in the real treatment was around 170, and the time spent for treatment was 194 days.

Evaluation method of membrane performance in membrane distillation process for seawater desalination.

PubMed

Chung, Seungjoon; Seo, Chang Duck; Choi, Jae-Hoon; Chung, Jinwook

2014-01-01

Membrane distillation (MD) is an emerging desalination technology as an energy-saving alternative to conventional distillation and reverse osmosis method. The selection of appropriate membrane is a prerequisite for the design of an optimized MD process. We proposed a simple approximation method to evaluate the performance of membranes for MD process. Three hollow fibre-type commercial membranes with different thicknesses and pore sizes were tested. Experimental results showed that one membrane was advantageous due to the highest flux, whereas another membrane was due to the lowest feed temperature drop. Regression analyses and multi-stage calculations were used to account for the trade-offeffects of flux and feed temperature drop. The most desirable membrane was selected from tested membranes in terms of the mean flux in a multi-stage process. This method would be useful for the selection of the membranes without complicated simulation techniques.

Bounding the marginal cost of producing potable water including the use of seawater desalinization as a backstop potable water production technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dooley, James J.

2014-04-01

The analysis presented in this technical report should allow for the creation of high, medium, and low cost potable water prices for GCAM. Seawater reverse osmosis (SWRO) based desalinization should act as a backstop for the cost of producing potable water (i.e., the literature seems clear that SWRO should establish an upper bound for the plant gate cost of producing potable water). Transporting water over significant distances and having to lift water to higher elevations to reach end-users can also have a significant impact on the cost of producing water. The three potable fresh water scenarios describe in this technicalmore » report are: low cost water scenario ($0.10/m3); medium water cost scenario ($1.00/m3); and high water cost scenario ($2.50/m3).« less

EMERGING TECHNOLOGY BULLETIN: NEW JERSEY INSTITUTE OF TECHNOLOGY - GHEA ASSOCIATES PROCESS

EPA Science Inventory

The GHEA Associates process applies surfactants and additives to soil washing and wastewater treatment to make organic and metal contaminants soluble (figure 1). The process components include a 25-gal extractor, solid liquid separation, rinse, mixer-settler, and ultrafiltration ...

Effect of electric field on the performance of soil electro-bioremediation with a periodic polarity reversal strategy.

PubMed

Mena, E; Villaseñor, J; Cañizares, P; Rodrigo, M A

2016-03-01

In this work, it is studied the effect of the electric fields (within the range 0.0-1.5 V cm(-1)) on the performance of electrobioremediation with polarity reversal, using a bench scale plant with diesel-spiked kaolinite with 14-d long tests. Results obtained show that the periodic changes in the polarity of the electric field results in a more efficient treatment as compared with the single electro-bioremediation process, and it does not require the addition of a buffer to keep the pH within a suitable range. The soil heating was not very important and it did not cause a change in the temperature of the soil up to values incompatible with the life of microorganisms. Low values of water transported by the electro-osmosis process were attained with this strategy. After only 14 d of treatment, by using the highest electric field studied in this work (1.5 V cm(-1)), up to 35.40% of the diesel added at the beginning of the test was removed, value much higher than the 10.5% obtained by the single bioremediation technology in the same period. Copyright © 2015 Elsevier Ltd. All rights reserved.

Enhanced capacity and stability for the separation of cesium in electrically switched ion exchange

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tawfic, A.F.; Dickson, S.E.; Kim, Y.

2015-03-15

Electrically switched ion exchange (ESIX) can be used to separate ionic contaminants from industrial wastewater, including that generated by the nuclear industry. The ESIX method involves sequential application of reduction and oxidation potentials to an ion exchange film to induce the respective loading and unloading of cesium. This technology is superior to conventional methods (e.g electrodialysis reversal or reverse osmosis) as it requires very little energy for ionic separation. In previous studies, ESIX films have demonstrated relatively low ion exchange capacities and limited film stabilities over repeated potential applications. In this study, the methodology for the deposition of electro-active filmsmore » (nickel hexacyanoferrate) on nickel electrodes was modified to improve the ion exchange capacity for cesium removal using ESIX. Cyclic voltammetry was used to investigate the ion exchange capacity and stability. Scanning electron microscopy (SEM) was used to characterize the modified film surfaces. Additionally, the films were examined for the separation of cesium ions. This modified film preparation technique enhanced the ion exchange capacity and improves the film stability compared to previous methods for the deposition of ESIX films. (authors)« less

Method of preparing water purification membranes. [polymerization of allyl amine as thin films in plasma discharge

NASA Technical Reports Server (NTRS)

Hollahan, J. R.; Wydeven, T. J., Jr. (Inventor)

1974-01-01

Allyl amine and chemically related compounds are polymerized as thin films in the presence of a plasma discharge. The monomer compound can be polymerized by itself or in the presence of an additive gas to promote polymerization and act as a carrier. The polymerized films thus produced show outstanding advantages when used as reverse osmosis membranes.

Sister Earth, Our Common Home: Toward a Sustainable, Planet Friendly Approach to Dialysis, a Paradigm of High Technology Medicine.

PubMed

Piccoli, Giorgina Barbara; Mery, David

2017-11-01

In our high-technology, highly polluted world, medicine plays an important role balancing saving lives with the expenses of growing amounts of waste products, not only biologically dangerous (the potentially "contaminated" or "hazardous" waste) but also potentially harmful for the planet (nonrecyclable, plastic waste). Dialysis, the prototype of high-technology medicine, is central to these problems, as the present treatment of about 2 million patients produces an enormous quantity of waste (considering hazardous waste only about 2 kg per session, with 160 sessions per year, that is 320 kg per patient, or about 640,000 tons of hazardous waste per year for 2 million patients, roughly corresponding to 6 nuclear aircraft carriers). Furthermore, obsolete dialysis machines, and water treatments are discharged, adding to the "technological waste." Water produced by the reverse osmosis is also discharged; this is the only nonhazardous, nonpolluting waste, but in particular in dry areas, wasting water is a great ecologic concern. The present review is aimed at discussing strategies already in place and to be further implemented for reducing this particular "uremic toxin" for the earth: dialysis waste, including dialysis disposables, water, and dialysis machines. Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Improvement of General Electric’s Chilled Ammonia Process with the use of Membrane Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muraskin, Dave; Dube, Sanjay; Baburao, Barath

General Electric Environmental Control Solutions (formerly Alstom Power Environmental Control Systems) set out to complete the Phase 1 award requirements for a Phase II renewal application for their project selected under DOE-FOA-0001190 “Small and Large Scale Pilots for Reducing the Cost of CO 2 Capture and Compression”. The project focus was to implement several improvement concepts utilizing membrane technology at the recipient’s Chilled Ammonia Process (CAP) CO 2 capture large-scale pilot plant. The goal was to lower the overall cost of technology. During the development of costs for the preliminary techno-economic assessment (TEA), it became clear that the capital andmore » operating costs of this concept were not economically attractive. All work related to a Phase II renewal application at that point was halted as GE made the decision not to submit a Phase II renewal application. Discussions with DOE resulted in a path towards useful information produced from the design and cost work already completed on the project. With the reverse osmosis (RO) unit providing most of the cost issues, GE would provide a sensitivity analysis of the RO unit with respect to project cost. This information would be included with the Techno-Economic Analysis along with the Technology Gap Analysis.« less

From lab to full-scale ultrafiltration in microalgae harvesting

NASA Astrophysics Data System (ADS)

Wenten, I. G.; Steven, S.; Dwiputra, A.; Khoiruddin; Hakim, A. N.

2017-07-01

Ponding system is generally used for microalgae cultivation. However, selection of appropriate technology for the harvesting process is challenging due to the low cell density of cultivated microalgae from the ponding system and the large volume of water to be handled. One of the promising technologies for microalgae harvesting is ultrafiltration (UF). In this study, the performance of UF during harvesting of microalgae in a lab- and a full-scale test is investigated. The performances of both scales are compared and analyzed to provide an understanding of several aspects which affect the yield produced from lab and actual conditions. Furthermore, a unique self-standing non-modular UF is introduced in the full-scale test. The non-modular UF exhibits several advantages, such as simple piping and connection, single pump for filtration and backwashing, and smaller footprint. With those advantages, the non-modular UF could be a promising technology for microalgae harvesting in industrial-scale.

Water distribution system and diarrheal disease transmission: a case study in Uzbekistan.

PubMed

Semenza, J C; Roberts, L; Henderson, A; Bogan, J; Rubin, C H

1998-12-01

Deteriorating water treatment facilities and distribution systems pose a significant public health threat, particularly in republics of the former Soviet Union. Interventions to decrease the disease burden associated with these water systems range from upgrading distribution networks to installing reverse osmosis technology. To provide insight into this decision process, we conducted a randomized intervention study to provide epidemiologic data for water policy decisions in Nukus, Uzbekistan, where drinking water quality is suboptimal. We interviewed residents of 240 households, 120 with and 120 without access to municipal piped water. Residents of 62 households without piped water were trained to chlorinate their drinking water at home in a narrow-necked water container with a spout. All study subjects (1583 individuals) were monitored biweekly for self-reported diarrheal illness over a period of 9.5 weeks. The home chlorination intervention group had the lowest diarrheal rate (28.8/1,000 subjects/month) despite lack of access to piped water in their homes. Compared with the two groups that did not receive the intervention this rate was one-sixth that of the group with no piped water (179.2/1,000 subjects/month) and one-third that of the households with piped water (75.5/1,000 subjects/month). More than 30% of the households with piped water lacked detectable levels of chlorine residues in their drinking water, despite two-stage chlorination of the source water, and were at increased risk of diarrhea. Forty-two percent of these municipal users reported that water pressure had been intermittent within the previous two days. The dramatic reduction in diarrheal rates in the home-chlorination intervention group indicates that a large proportion of diarrheal diseases in Nukus are water-borne. The home-chlorination group had less diarrhea than the group with piped water, implicating the distribution system as a source of disease transmission. Taken together, these epidemiologic data would support the hypothesis that diarrhea in the piped water group could be attributed to cross-contamination between the municipal water supply and sewer, due to leaky pipes and lack of water pressure. Relatively inexpensive steps, including chlorination, maintaining water pressure, and properly maintaining the distribution system, rather than reverse osmosis technology, should reduce diarrheal rates.

A new class of draw solutions for minimizing reverse salt flux to improve forward osmosis desalination.

PubMed

Nguyen, Hau Thi; Nguyen, Nguyen Cong; Chen, Shiao-Shing; Ngo, Huu Hao; Guo, Wenshan; Li, Chi-Wang

2015-12-15

The applications of forward osmosis (FO) have been hindered because of the lack of an optimal draw solution. The reverse salt flux from the draw solution not only reduces the water flux but also increases the cost of draw solute replenishment. Therefore, in this study, Tergitol NP7 and NP9 with a long straight carbon chain and low critical micelle concentration (CMC) were coupled with highly charged ethylenediaminetetraacetic acid (EDTA) as an innovative draw solution to minimize reverse salt diffusion in FO for the first time. The results showed that the lowest reverse salt flux of 0.067 GMH was observed when 0.1M EDTA-2Na coupled with 15mM NP7 was used as a draw solution and deionized water was used as a feed solution in FO mode (active layer facing with the feed solution). This is due to the hydrophobic interaction between the tails of NP7 and the FO membrane, thus creating layers on the membrane surface and constricting the FO membrane pores. Moreover, 1M EDTA-2Na coupled with 15mM NP7 is promising as an optimal draw solution for brackish water and sea water desalination. Average water fluxes of 7.68, 6.78, and 5.95 LMH were achieved when brackish water was used as a feed solution (5, 10, and 20g/L NaCl), and an average water flux of 3.81 LMH was achieved when sea water was used as a feed solution (35g/L NaCl). The diluted draw solution was recovered using a nanofiltration (NF-TS80) membrane with a high efficiency of 95% because of the high charge and large size of the draw solution. Copyright © 2015 Elsevier B.V. All rights reserved.

Testing of Synthetic Biological Membranes for Forward Osmosis Applications

NASA Technical Reports Server (NTRS)

Parodi, Jurek; Mangado, Jaione Romero; Stefanson, Ofir; Flynn, Michael; Mancinelli, Rocco; Kawashima, Brian; Trieu, Serena; Brozell, Adrian; Rosenberg, Kevan

2016-01-01

Commercially available forward osmosis membranes have been extensively tested for human space flight wastewater treatment. Despite the improvements achieved in the last decades, there is still a challenge to produce reliable membranes with anti-fouling properties, chemical resistance, and high flux and selectivity. Synthetic biological membranes that mimic the ones present in nature, which underwent millions of years of evolution, represent a potential solution for further development and progress in membrane technology. Biomimetic forward osmosis membranes based on a polymeric support filter and coated with surfactant multilayers have been engineered to investigate how different manufacturing processes impact the performance and structure of the membrane. However, initial results of the first generation prototype membranes tests reveal a high scatter in the data, due to the current testing apparatus set up. The testing apparatus has been upgraded to improve data collection, reduce errors, and to allow higher control of the testing process.

COHO - Utilizing Waste Heat and Carbon Dioxide at Power Plants for Water Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaur, Sumanjeet; Wilson, Aaron; Wendt, Daniel

The COHO is a breakthrough water purification system that can concentrate challenging feed waters using carbon dioxide and low-grade heat. For this project, we studied feeds in a lab-scale system to simulate COHO’s potential to operate at coal- powered power plants. COHO proved successful at concentrating the highly scaling and challenging wastewaters derived from a power plant’s cooling towers and flue gas desulfurization units. We also found that COHO was successful at scrubbing carbon dioxide from flue gas mixtures. Thermal regeneration of the switchable polarity solvent forward osmosis draw solution ended up requiring higher temperatures than initially anticipated, but wemore » also found that the draw solution could be polished via reverse osmosis. A techno-economic analysis indicates that installation of a COHO at a power plant for wastewater treatment would result in significant savings.« less

Elastic Valve Using Induced-Charge Electro-Osmosis

NASA Astrophysics Data System (ADS)

Sugioka, Hideyuki

2015-06-01

Biomimic devices using induced-charge electro-osmosis (ICEO) is interesting since they have the possibility to realize high-performance functions with simple structures and with low-energy consumption. Thus, inspired by a cilium, we propose a two-dimensional artificial elastic valve using hydrodynamic force due to ICEO with a thin elastic beam in a microfluidic channel and numerically examine the valving performance. By an implicit strongly coupled simulation technique between a fluid and an elastic structure based on the boundary-element method, along with the thin-double-layer approximation, we realize stable calculations and find that the elastic valve using ICEO functions effectively at high frequency with low applied voltages in a realistic pressure flow. Further, we also examine passive motion of the valve; i.e., it stops a reverse flow effectively and releases a forward flow in the channel. We believe that our device can be used in a wide range of microfluidic applications, such as mixers, pumps, etc.