Showing papers on "Desalination published in 1998"
TL;DR: In this article, a nanofiltration (NF) membrane unit, which received non-coagulated filtered seawater feed, was placed ahead of the SWRO and the MSF pilot plant units to form, for the first time ever, fully integrated desalination systems.
226 citations
TL;DR: In this article, the closed air cycle humidification-dehumidification process was used for water desalination using solar energy, where the circulated air by natural or forced convection was heated by the hot water obtained either from a flat plate solar collector or from an electrical heater.
188 citations
TL;DR: In this article, an air-gap module with built-in condensing surface was used for conducting experiments on polyvinylidene fluoride flat membrane sheets and the quality of the permeate, quantified by conductivity measurements, and the percolation flux were monitored as the feed temperature, feed flow rate, cooling temperature, and cooling water flow fate were varied.
Abstract: Membrane distillation was investigated as a possible technique for desalination. An air-gap module with built-in Condensing surface was used for conducting experiments on polyvinylidene fluoride flat membrane sheets. The feed stream tested was artificial seawater. The quality of the permeate, quantified by conductivity measurements, and the permeate flux were monitored as the feed temperature, feed flow rate, cooling temperature, and cooling water flow fate were varied. The effect of the distance between the membrane and condensing surface was investigated by adjusting the air gap within the module. A mathematical model incorporating temperature and concentration polarization effects was developed and validated on the experimental data. Good agreement between experimental and predicted values was obtained.
178 citations
TL;DR: In this article, the authors present an overall review and technical assessment of the various and up-to-date developments in single and multi-effect solar stills, the development in still configurations, the problems encountered with units during the course of operation as well as the impact on the environment are addressed.
176 citations
TL;DR: In this paper, pressure-retarded osmosis (PRO) was proposed for handling seawater brought to the Dead Sea, both processes taking advantage of the 400 m drop to Dead Sea level and both sized to replenish the 3,000,000 m3/d evaporation rate of the Dead sea.
174 citations
TL;DR: In this paper, a multi-stage RO membrane sea desalination process and a low pressure RO process can be recommendable for boron management with a reasonable additional cost in drinking water supply.
141 citations
TL;DR: In this paper, an electrodialysis-stack design with a membrane length of 1 m was employed for nitrate removal at the Kleylehof well in Eastern Austria, where the average nitrate concentration in the raw water was 80 to 100 mg/l NO3.
137 citations
TL;DR: In this paper, the role of the coupled transport phenomena role in enhancement of salt ions transfer at electrodialysis of moderate-dilute and dilute electrolyte solutions in membrane modules of various constructions was measured.
124 citations
TL;DR: In this paper, the results of lab and pilot scale tests have shown that membranes can be used with the rinsing water from dyeing of cotton and polyester fabrics in textile dyehouse.
114 citations
TL;DR: In this article, various desalination methods are analyzed with respect to their primary energy consumption, sea-water treatment requirement and equipment cost, and the multiple effect boiling evaporator is concluded to be the most suitable method for stimulation by solar energy.
110 citations
Patent•
12 Oct 1998
TL;DR: In this paper, an approach for producing potable water from an aqueous feed such as seawater utilizing a pressure vessel designed for operation in the range of about 250 psig to about 350 psig having reverse osmosis (RO) separation elements disposed upstream of at least one nanofiltrate separation element.
Abstract: Apparatus and methods for producing potable water from an aqueous feed such as seawater utilizing a pressure vessel designed for operation in the range of about 250 psig to about 350 psig having reverse osmosis (RO) separation elements disposed upstream of at least one nanofiltrate separation element. The supply of seawater at such pressure creates no permeate flow through the RO membranes, so the seawater flushes the feed side of the RO elements on its way to the NF element where very substantial permeate flux occurs, producing a NF permeate substantially depleted in divalent ions and optionally moderately depleted in monovalent ions. The NF permeate is collected in a holding tank having liquid level switches, and when a desired level is reached, a control system causes the pump to draw suction from the holding tank while shutting off feed from the seawater source. When the NF permeate is supplied to the feed side of the RO elements, its osmotic pressure is such that substantial RO permeation now occurs creating a stream of good quality potable water. During both stages of operation, energy is conserved by routing the concentrate stream leaving the pressure vessel through an energy recovery device that boosts the pressure of the liquid being discharged from the positive displacement pump.
TL;DR: The Saline Water Conversion Corporation, Research and Development Center (SWCC-RDC) carried out exploratory research study to evaluate the adaptability of the brackish water softening nanofiltration technique as a permeation pretreatment of feed to seawater reverse osmosis (SWRO) and as make-up to MSF.
Patent•
25 Sep 1998
TL;DR: In this article, a desalination process is described which combines two or more substantially different water treatment processes in an unique manner to desalinate saline water, especially sea water, to produce a high yield of high quality fresh water, including potable water, at an energy consumption equivalent to or less than much less efficient prior art processes.
Abstract: A desalination process is disclosed which combines two or more substantially different water treatment processes in an unique manner to desalinate saline water, especially sea water, to produce a high yield of high quality fresh water, including potable water, at an energy consumption equivalent to or less than much less efficient prior art desalination processes. In this process a nanofiltration step is synergistically combined with at least one of sea water reverse osmosis, multistage flash distillation, multieffect distillation of vapor compression distillation to provide an integrated desalination system by which sea water can be efficiently and economically converted to high quality potable water in yields which are at least 70 %-80 % greater than the yields available from the prior art processes. Typically a process of this invention using the nanofiltration initial step will produce, with respect to sea water feed properties, calcium, magnesium, sulfate and bicarbonate ion content reductions of 63 %-94 %, pH decreases of about 0.4-0.5 units and total dissolved solids content reductions of 35 %-50 %.
TL;DR: In this paper, simulation is used to evaluate the performance of the municipal water system in Fukuoka city, and a kind of risk model incorporating water demand prediction is presented in combination with daily simulation model, and the results obtained show that savings of between 5 and 12% of water consumption from May 1, or increasing of daily desalination of sea water about 30, 000 m3 or more, may efficiently decrease the performance risk of the water supply system.
Abstract: In this study, simulation is used to evaluate the performance of the municipal water system in Fukuoka city. In combination with daily simulation model, a kind of risk model incorporating water demand prediction is presented. This model applies five risk indices: reliability, resiliency, vulnerability, drought risk index (DRI) and drought damage index (DDI). They aid in the identification of operation policies for the municipal water system, and the planning and operational policies obtained are aimed at achieving minimum risk for a given scenario of operation. In this paper, the performance risk of the municipal water system is investigated under three alternatives: (1) the existing system operation when available supply from the Chikugo river is decreased; (2) water restrictions for different percentages of reduction are implemented; and (3) available water supply increases when desalination of sea water is implemented. The results obtained show that savings of between 5 and 12% of water consumption from May 1, or increasing of daily desalination of sea water about 30 000 m3 or more, may efficiently decrease the performance risk of the Fukuoka water supply system. Potentials also exist for further increase of reservoir storage by more rational operation. The measure that more attention should be paid to increasing the water supply from stable sources is recommended as well.
TL;DR: In this paper, the authors presented the work performed within the project "INTERSUDMED-Prefeasibility Study for the Integration of RES for Electricity Production in South Mediterranean Countries" of the European Commission's JOULE Programme.
TL;DR: In this paper, the results of experiments carried out with a capillary film solar distiller installed in the south of Algeria (in a village near Touggourt where the temperature of the groundwater is about 65°C at the source) for groundwater distillation and to improve the efficiency of the DIFICAP (DI stiller with a FI lm in CAP illary motion) was presented.
TL;DR: In this article, a reverse osmoisis (RO) plant supplied by a photovoltaic (PV) power supply has been installed at the island of Gran Canaria.
TL;DR: In this article, the selective removal of chloride from a solution with high ionic strength containing multiple divalent anions, using electrodialysis with monovalent selective ion exchange membranes is described.
Patent•
[...]
09 Jan 1998
TL;DR: In this article, a desalinator is disclosed for removing dissolved solids from sea water or brackish water, where three electrical coils (94, 96 and 98) encircle the cartridge and are embedded in the walls of the casing.
Abstract: A desalinator is disclosed for removing dissolved solids from sea water or brackish water. The desalinator (10) comprising a casing (12) into which a pump (14) driven by a motor (16) pumps sea water or brackish water under pressure. A desalination cartridge (76) within the casing (12) includes semi-permeable material which acts as a reverse osmosis membrane and through which permeate is forced to separate it from the sea water or brackish water. The solids dissolved in the brackish water or sea water are retained in the salt retention passages of the cartridge (76). Three electrical coils (94, 96 and 98) encircle the cartridge (76) and are embedded in the walls of the casing (12). The coils are supplied with current from a supply (112) which is preferably a 50 Hertz, 380 Volt three phase supply. The coils are also connected by lines (108) to an adjustable frequency AC drive (110) which is in turn connected to the motor (16). The coils (94, 96 and 98) impose a magnetic field on the sea water or brackish water in the salt retention passages which enhances the rate at which water permeates through the reverse osmosis membrane and also inhibits fouling. The coils (94, 96 and 98) additionally act as chockes for the motor (16).
TL;DR: In this paper, the authors discussed the biofouling tendency of various water streams (specially Gulf water) is discussed in order to account for its dependence on water quality and membrane module applied.
TL;DR: In this paper, an investigation of the technical feasibility and a cost benefit analysis of a brackish water small-scale desalination plant in a rural area has been carried out, which revealed the best socioeconomic performance for a reverse osmosis directly coupled with a photovoltaic-system.
TL;DR: In this paper, the performance of a pilot solar Multi Effect Humidification (MEH) Desalination system in Fuerteventura, Canary Islands, had been measured and analyzed in detail by the ZAE Bayern since 1992.
TL;DR: In this article, the performance characteristics of a multi-stage flash desalination process were analyzed based on a number of simplified configurations, including a single-stage flashing unit, a once-through multistage flashing system, and configurations with brine recycle.
Patent•
06 Apr 1998
TL;DR: A reverse osmosis composite membrane as discussed by the authors comprises a sponge layer and a separation layer formed on a surface of the sponge layer, and the specific surface area of the layer in which the at least one substance is present or the separation layer before the surface coating is in the range of 2 to 1,000.
Abstract: A reverse osmosis composite membrane comprises a sponge layer, and a separation layer formed on a surface of the sponge layer, wherein at least one substance selected from the group consisting of an electrically neutral organic substance and an electrically neutral polymer is present in the separation layer or a surface of the separation layer is coated with at least one substance selected from the group consisting of an electrically neutral organic substance and an electrically neutral polymer, and wherein the specific surface area of the layer in which the at least one substance is present or the separation layer before the surface coating is in the range of 2 to 1,000 The reverse osmosis composite membrane has a high salt rejection, a high water permeability, and a high fouling tolerance, and permits practical desalination at a relatively low pressure
TL;DR: In this article, a solar still plant capacity of 5.8 m 3 distillate per day is proposed to couple with the existing PV-RO plant in order to utilize most of the reject brine instead of releasing it into the ground.
Patent•
24 Dec 1998TL;DR: In this article, a desalination system capable of obtaining fresh water stably at low cost by utilizing low-temperature waste, where a heat exchanger cooperates with an evaporation can to heat exchange and generate water vapor.
Abstract: A desalination apparatus capable of obtaining fresh water stably at low cost by utilizing low-temperature waste, wherein the desalination apparatus including a heat exchanger (92) cooperating with an evaporation can (60) so as to subject a low-temperature waste heat (11) and raw water (62) in the evaporation can (60) to heat exchange and generate water vapor (63) in the evaporation can (60); a condenser (98) cooperating with a raw water tank (72) so as to receive the water vapor (63) from the evaporation can (60), cool the water vapor (63) by subjecting the water vapor (63) and raw water (71) in the raw water tank (72) to heat exchange and obtain distilled water (76); a distilled water tank for storing the distilled water (76); vacuum means for evacuating the evaporation can (60) and depressurizing the inside thereof so as to promote generation of water vapor (63) in the evaporation can (60); and raw water supply means for supplying raw water to the evaporation can.
Dissertation•
17 Apr 1998
TL;DR: In this article, a mathematical model and its solution procedure are developed to simulate the steady-state and dynamic behaviour of multistage flash desalination plants, which are based on the same set of equations and are of the same order.
TL;DR: In this paper, the behavior of the ultra-low pressure RO membranes in the full-scale system is investigated. And several design options will be evaluated for their effectiveness in improving system designs incorporating ultra low pressure membranes.
TL;DR: In this paper, the cogeneration of electricity and potable water utilizing solar energy is studied, assuming solar tower power plants with the open volumetric PHOEBUS receiver, and the results show that the water production cost is about the same or even lower than the cost of water produced by conventionally fired systems.