Showing papers on "Reverse osmosis published in 2000"
TL;DR: Membrane technology for the processing of fruit juices and beverages has been applied mainly for clarification using ultrafiltration and microfiltration, and for concentration using reverse osmosis.
Abstract: Membrane technology for the processing of fruit juices and beverages has been applied mainly for clarification using ultrafiltration and microfiltration, and for concentration using reverse osmosis. The effects of product preparation, membrane selection, and operating parameters are important factors influencing filtration rate and product quality. Technological advances related to the development of new membranes, improvement in process engineering, and better understanding of fruit beverage constituents have expanded the range of membrane separation processes. Developments in novel membrane processes, including electrodialysis and pervaporation, increased the array of applications in combination with other technologies for alternate uses in fruit juices and beverages.
197 citations
TL;DR: In this article, the effect of these parameters on brackish water, previously subjected to a desalination stage, is analyzed and the results show an increase in the rejection of boron at pH values of 9.5 and above.
181 citations
TL;DR: In this paper, more attention is given to the fundamental and engineering aspects of this biofouling phenomena covering the basic various mechanisms of its multisteps formation processes and its negative effects on the plant performances.
176 citations
Patent•
01 Sep 2000
TL;DR: In this article, a cost-effective process for separating contaminants and a wide range of fouling material from surface water, ground water and from industrial effluents is proposed, where cationic inorganic and/or polymeric flocculants are used to coagulate and focculate the water-borne colloidal matter (e.g. clays, iron hydroxides, naturally occurring matter (NOM's), followed by filtration using a multi-media filter, charge neutralization and reversal and final filtraction using a 5-
Abstract: This invention discloses a cost-effective process for separating contaminants and a wide-range of fouling material from surface water, ground water and from industrial effluents. Having undergone effective pre-treatment, the water can be purified further by using high-surface area spirally wound micro-filtration (MF), ultra-filtration (UF), nano-filtration (NF) or reverse osmosis (RO) membranes. High-quality potable water free from pathogen and other contaminants is thus produced at low-cost from the pre-treated surface water and ground-water. Conversely, pre-treated industrial effluents are further purified at a relatively low-cost using NF or RO membranes, thus producing water suitable for recycle or surface discharge. The process of this invention uses cationic inorganic and/or polymeric flocculants to coagulate and flocculate the water-borne colloidal matter (e.g. clays, iron hydroxides, naturally occurring matter (NOM's), etc.), followed by filtration using a multi-media filter, charge neutralization and reversal and final filtration using a 5-micron cartridge filter. These pre-treatment steps provides a good quality water having a low Silt Density Index and a significant negative zeta potential, thereby ensuring against irreversible chemical fouling of the spirally-wound membranes.
162 citations
TL;DR: In this paper, the porosity parameters of some commercial polyamide thin-film composite membranes, and their influence on membrane performance, were determined at two operating pressures using model inorganic and organic aqueous solutions.
138 citations
TL;DR: The Ministry of Water Resources successfully conducted an experimental study on the use of solar power to desalinate brackish ground water at their Heelat ar Rakah camp, a remote location some 900 km south of Muscat, the capital of Oman as discussed by the authors.
121 citations
TL;DR: In this paper, 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.
Abstract: 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 that 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.
112 citations
TL;DR: In this article, the authors showed that nanofiltration (NF) pretreatment of seawater feed to seawater desalination plants removed from its turbidity and microorganism, caused significant rejection of the scale forming hardness ions, reduced TDS in Gulf seawater and produced a new, partially desalinated seawater product, considerably different from seawater in qualities and without the problems normally associated with seawater of high concentration of scale forming ions.
105 citations
TL;DR: In this article, the effectiveness of reverse osmosis and nanofiltration under various solution chemistries, on bacterial regrowth potential as quantified by assimilable organic carbon and biodegradable dissolved organic carbon (BDOC), was evaluated.
104 citations
TL;DR: In this paper, it was shown that water for reuse could be produced from low-contaminated process water streams from food processing companies by a specific treatment using membrane processes while achieving reduction of water consumption and wastewater quantities.
103 citations
TL;DR: In this paper, a scaling monitor called ScaleGuard was developed and tested at a pilot plant treating anaerobic groundwater for the production of drinking water for the purpose of early detection of scaling.
TL;DR: In this paper, the authors describe properties of low fouling membrane technology and present results of its application with conventional and capillary pretreatment in municipal wastewater reclamation applications and compare with that of conventional membrane technology.
TL;DR: In this paper, the requirements for water reuse of dairy industry treatment plant effluents are described, and two alternative membrane processes are described: reverse osmosis (RO) and Nanofiltration (NF) membrane processes.
TL;DR: In this article, the authors show that either the compaction of the presently available RO membranes or costs limit the operating pressure to about 150 bar maximum, and the integration of a nanofiltration into a staged RO process can solve the problem in cases where chlorides are the reason for high osmotic pressures and scaling is due to calcium sulfates.
TL;DR: In this article, a nanofiltration (NF) membrane process coupled with a bicycle pumping system was examined by using arsenic-contaminated tube well water in a rural area of Bangladesh.
TL;DR: The study investigated the environmental and pretreatment impact on biofouling in a seawater reverse osmosis (SWRO) plant and indicates that the questionable quality of source water is one cause of the operational problems in this plant.
TL;DR: In this paper, a large-scale pilot plant for the treatment of water from the River Weser by the combination of direct ultrafiltration and reverse osmosis (total capacity 36 m 3 /h RO-permeate) is presented.
TL;DR: In this article, 4, 8 and 9 inch membrane elements used in NF or NF/SWRO combination to provide make-up to pilot plant MSF of 20 kl/d distiller.
TL;DR: In this paper, the efficiency of the combined processes, known as Integrated Membrane Systems, for surface water treatment was evaluated on polluted low salinity water: UF and conventional train prior low fouling reverse-osmosis membranes (LFRO).
TL;DR: In this article, a 15-month operation of a low pressure reverse osmosis (RO) membrane pilot plant to treat a highly organic surface water from the Hillsborough River in Tampa, Florida, using various surface analytical techniques.
Abstract: The goal of this study is to identify the causes of membrane failure observed during a 15-month operation of a low pressure reverse osmosis (RO) membrane pilot plant to treat a highly organic surface water from the Hillsborough River in Tampa, Florida, using various surface analytical techniques. Three different commercial RO membranes, made of cellulose acetate or polyamide, were used in this pilot study, and all of these membranes showed performance deterioration presumably due to membrane fouling and degradation at given experimental conditions. In order to elucidate the mechanisms of membrane failure, scanning electron microscopy with energy dispersive spectrometry (SEM/EDS), x-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR) were performed on the surface of the polymeric RO membranes used. More specifically, molecular composition including surface functional groups were identified from XPS analysis, confirmed by FTIR, and correlated to membrane failure. In addi...
TL;DR: In this paper, the recovery of valeric acid from a synthetic aqueous solution simulating a wastewater stream in nylon manufacturing has been carried out using freeze concentration and reverse osmosis as separation processes.
TL;DR: In 1999, the City of Laitila constructed a membrane filtration plant (16-25m3/h) to control fluoride and aluminium concentration in drinking water as discussed by the authors.
TL;DR: In this paper, the mass transfer coefficient of a spiral-type reverse osmosis (RO) element was measured using a polyamide membrane, designated UTC-80, and an appropriate correlation equation was obtained.
Abstract: Membrane transport parameters from a running plant data were studied to understand their changes with time, as well as the causes of membrane fouling under various running conditions. First, the mass-transfer coefficient of a spiral-type reverse osmosis (RO) element was measured using a polyamide membrane, designated UTC-80, and an appropriate correlation equation was obtained. Then, a computer program was developed to obtain membrane transport parameters from flux and rejection data of an actual RO plant. When it became apparent that the temperature corrections should be applied, laboratory experiments were used to determine them. Thus, the time course change of both solution and salt permeabilities and the relation between them could be followed. The permeability of each ion or solute can be obtained by the same method when their analytical data are available.
TL;DR: Positron annihilation lifetime spectroscopy has been adopted as a new approach for studying vacancies of reverse osmosis membrane materials composed of cellulose acetate films and aromatic polyamide resins as discussed by the authors.
TL;DR: In this article, a 13,000 Da membrane was selected as the most promising reference membrane for application in the MFI-UF test, which was used to measure the particulate fouling potential of RO feedwater and evaluate the efficiency of pretreatment processes on particle removal at two RO pilot plants.
01 Jan 2000
TL;DR: In this article, a full-scale Ultra-filtration plant for drinking water in the UK has been reported to have achieved state-of-the-art performance for 90 MLD Cryptosporidium-and Giardia-free drinking water.
Abstract: Case Studies: Membrane Case Studies, Past, Present and Future Sea Water Reverse Osmosis - The Largest Plant in British Waters Drinking Water Sources in Kuwait Nanofiltration for Colour Removal - 7 Years Operational Experience in Scotland Ultrafiltration for 90 MLD Cryptosporidium-and Giardia-free Drinking Water Application of a New Generation Microfiltration Process for Large Scale Water and Wastewater Treatment Water Quality and Treatment: The UK System of Approval of Products Used in Contact with Drinking Water Immersed Membranes for Drinking Water Production Phosphate and Iron Removal from Seepage and Surface Water by Microfiltration Reuse of Filter Backwash Water as a Source for Drinking Water Production: Piloting and Implementation of a Full-scale Ultrafiltration Plant Improved Performance of Drinking Water Microfiltration with Hybrid Particle Pre-treatment River Trent On Tap - Comparison of Conventional and Membrane Treatment Processes The Use of Electrodialysis at Amsterdam Water Supply Applying Electrodialysis (EDR) Technology to Underground Water Treatment Nanofiltration for Drinking Water Treatment from a Eutrophied Lake in Taiwan Fouling and Cleaning: Membranes and Microorganisms - Love at First Sight and the Consequences Optimising Membrane Performance - Practical Experiences Fouling Characteristics of Membrane Filtration in Membrane Bioreactors Cleaning of Membranes in Water and Wastewater Applications Water Reuse: Water Reuse for the Next Millennium - Membrane Treatment at the Millennium Dome Wastewater Reclamation Case Studies, the Benefits of Outsourced Membrane Systems Comparison between Different Out-to-in Filtration MF/UF Membranes for the Re-use of Biologically Treated Wastewater Effluent Industrial Applications: Sulphate Removal Membrane Technology: Application to the Janice Field SASOL's Experience in the Desalination and Re-use of Acid Mine Drainage and Ash Water Recovery of Wool Scouring Effluent Utilising Membrane Bioreactor (MBR) Technology as Part of the Activated Sludge System followed by Two-stage Reverse Osmosis (RO) Membrane Concentration Performance on a Real Industrial Effluent using a ZenoGem (R) MBR Membrane Technology in Wood, Pulp and Paper Industries Case Studies of Wastewater Re-use for Petrochemical, Power and Paper Industry Practical Experience with a Membrane Bioreactor for Wastewater Treatment-semi-cross-flow Ultrafiltration Treating Highly Coloured Waters: Design Innovations and Implications Treatment of Leachate by the MBR Process (Membrane Bioreactor) Operation of a Zero Discharge Wood Pulp Effluent Treatment Plant Integration of Maintenance and Operation into the Design of Reverse Osmosis Membrane Networks Microfiltration and Reverse Osmosis of Knostrop Final Effluent Modelling Temperature and Concentration Polarisation in Ultrafiltration of Non-Newtonian Fluid under Non-isothermal Conditions Novel Methods of Hollow Fibre Membrane Integrity Monitoring Comparison of Chemical Pretreatment Methods for Nanofiltration of Cold, Soft and Humic Waters In-situ Ultrasonic Measurements of Fouling and Cleaning Processes in Spiral-wound Membrane Modules A Novel Way to Treat Textile Wastewater with Nanofiltration and Adsorption.
Patent•
21 Dec 2000
TL;DR: In this article, a desalination system is driven by a solar powered boiler that outputs a pressurized vapor to drive an expander that generates output motive force to output pressurized saline water.
Abstract: A desalination system is driven by a solar powered boiler that outputs a pressurized vapor to drive an expander that generates output motive force. A pump is responsive to the motive force to output pressurized saline water. A reverse osmosis unit receives the pressurized saline water to output fresh water and pressurized brine. A recuperator that transfers heat from the expander exhaust to the boiler feed liquid is incorporated to improve the efficiency of the system. In a particular embodiment, a hydraulic motor receives the pressurized brine and outputs an augmenting motive force to the pump. In another embodiment, a novel motorless boiler feed pump is defined.
TL;DR: In this article, a zeolite membrane was firstly applied to the reverse osmosis process and it showed 044 rejection from 10wt% ethanol water mixture, and was stable to applied pressures up to 50 kgf cm-2.
Abstract: The reverse osmosis process needs no phase transformation during separation, and thus it has a potential in saving energy for liquid mixture separations Application of reverse osmosis to organic liquid is limited, owing to the lower stability of polymer membranes against organic liquid Zeolites are inorganic materials having durability against organic liquid and heat, and they show good separation ability in pervaporation In this study, zeolite membrane was firstly applied to the reverse osmosis process Zeolite A membrane, having thickness around 5 μm, showed 044 rejection from 10wt% ethanol water mixture The membrane was stable to applied pressures up to 50 kgf cm–2
TL;DR: In this article, computer calculation techniques are developed that enable us to determine optimum characteristics of membrane water treatment systems, such as pressure, recovery, membrane type etc. corresponding to optimum quality water composition (required hardness, fluoride, chloride and TDS content).
Patent•
12 Apr 2000
TL;DR: In this article, an apparatus 10 generates oxygenated water having a significantly reduced oxidation reduction potential (ORP) by removing particulate impurities from the water as it comes into the apparatus, and a reverse osmosis unit 200 further cleans and purifies the water, removing any additional solids and chlorides.
Abstract: An apparatus 10 generates oxygenated water having a significantly reduced oxidation reduction potential (ORP). A carbon filter 100 removes particulate impurities from the water as it comes into the apparatus. A water softener 150 removes minerals from the water. A reverse osmosis unit 200 further cleans and purifies the water, removing any additional solids, and almost all the minerals and chlorides. A blender 250 adds a precisely measured amount of sodium bicarbonate or sodium carbonate to the water, thereby making it somewhat electrically conductive. The purified water having a measured quantity of sodium bicarbonate is stored in a tank 300 which also includes a recirculating pump 350 which keeps the water moving. By keeping the water moving, the minimum level of sodium bicarbonate required for electrical conductivity may be used. A pump 400 moves the water into an electrolysis cell 450 , where current passing through the water separates a small amount of water into hydrogen and oxygen. The water is then transferred to a sparging unit 500 , where it flows in a spiraling manner in an oxygen-rich environment, thereby further increasing the oxygen level to approximately 50 to 60 ppm.