Showing papers on "Reverse osmosis published in 1977"

Desalination process system and by-product recovery

Abstract: A desalination process system combining electro-dialysis, reverse osmosis and brine concentration with by-product recovery.

Reverse osmosis membrane

Abstract: In a reverse osmosis membrane of the structure of Loeb's membrane for use to purify sea-water into plain water, the membrane comprises a skin layer as an active layer and a gel layer to support the skin layer, wherein an improvement of flux, that is the (passing rate of purified water) is achievable by burying a porous sheet, such as plain-woven cloth or non-woven fabric, in the gel layer.

Method and apparatus for recovering liquid and solid constituents of water solutions containing sparingly soluble solids

Abstract: Water, such as the effluent from cooling towers, boilers, waste streams of industrial plants, hydrometallurgical processes or other sources of water solutions containing sparingly soluble solids is efficiently separated into its aqueous and solid constituents by reverse osmosis and chemical treatments effective to achieve a zero discharge of effluent and a minimum volume of sludge or a recovery of valuable solids.

Water storage control for reverse osmosis system

Abstract: A reverse osmosis system employs a tank for storing permeate under a pressure which is a portion of the pressure of feed water introduced into a pressure resistant container housing a semipermeable membrane cartridge. Control means such as an automatic valve, preferably of the double diaphragm type, in the line introducing feed water into the pressure resistant container closes to shut off feed water flow when the pressure in the permeate storage tank reaches a first predetermined value, less than the feed water pressure, and re-opens to re-establish feed water flow at a second predetermined pressure lower than the first or shut-off pressure. A constricted passageway device such as a venturi in the pipe or connection between a dispensing device such as a faucet and the permeate storage tank has its throat communicating with the sensing conduit for actuating the feed water control valve. When the dispensing faucet is opened, flow of permeate through the venturi creates an amplified and drastically reduced pressure in the sensing conduit, and applies a servo or magnified actuation force to the valve in the re-open end of its control range.

Extraction and identification of organic micropollutants: reverse osmosis method*

Abstract: It is becoming increasingly apparent that our environment contains many substances of which we are unaware. The significane of these components, either alone or in combination with other factors, is not readily apparent. The assessment of the health effects of traces of organic chemicals in drinking water presents a formidable problem. Much of the organic material, perhaps 8090%, is not amenable to analysis by gas chromatographic methods. Evaluation of this uncharacterized fraction requires its isolation from drinking water samples. Achievement of this goal requires the initial concentration of the organic chemicals, because they are present in most drinking waters a t such low concentrations that they cannot be readily detected and studies toxicologically by present techniques. This concentration step must be performed in a manner that assures that the chemical species are not altered or destroyed. The concentration must yield at least a representative fraction of the solutes present or, preferably, a quantitative recovery of the solutes. The use of reverse osmosis, to produce concentrated aqueous solutions of organics, as a step in isolating organics from drinking water has been previously reported . This step is accomplished by applying pressure to a water sample in contact with a semipermeable membrane. The water passes through the membrane, leaving the dissolved matter behind. This procedure reduces the sample to a volume that can be practically handled by extraction and adsorption techniques in the laboratory to isolate the organics. The theory and practice of reverse osmosis have been adequately reviewed This paper describes modifications of the reverse osmosis system described earlier,* its application in the field to collect samples for bioassay, and the results of a study undertaken to determine if organic compounds are introduced into the sample by the reverse osmosis equipment.

Processing of whey by means of membranes and some applications of whey protein concentrate

Abstract: Data are given for processing Gouda cheese whey by reverse osmosis as preconcentration before transport or evaporation or ultrafiltration. Concentration costs for reverse osmosis are less than those for evaporation at ×2 concentration. Data are given for processing Gouda whey by ultrafiltration. Means to reduce oxidation defects in dried whey protein concentrate during storage are discussed. Applications of whey protein concentrate in soft drinks and in flour confectionery are described.

Process for de-salting of water and apparatus for performing this process

Abstract: Process for desalting of water by hyperfiltration (reverse osmosis), characterized in conveying the water to be desalted through at least one magnetic field and keeping the water streaming within the magnetic field and by removing via a throttle area a partial stream of the water to be desalted or of the water enriched in salt, respectively, from the pressure chamber located before the semipermeable membrane.

Conversion of sea water by reverse osmosis

Abstract: A process for recovery of fresh water by reverse osmosis from high salt content feed, such as sea water, comprises treating the feed water in an initial stage at relatively low pressure (between about 300 and 550 psi) employing a loose semipermeable membrane, to produce an intermediate product water containing one-fourth to one-half the TDS (total dissolved solids) content of the original feed water. The intermediate product water is treated in a subsequent stage also at a relatively low pressure (between about 300 and 550 psi) employing a tight semipermeable membrane, to produce a fresh product water containing less than 2,000 ppm TDS, and preferably a potable water containing less than 1,000 ppm TDS.

Process of treating waste water from a textile vat dyeing operation to produce a concentrate for reuse

Abstract: Process of treating waste water from a textile vat dyeing operation containing water, vat dyes, and dissolved and undissolved impurities including salts, lint, foreign matter, etc. to produce a concentrate suitable for direct reuse in the vat dyeing operation to conserve the use of dyes and water, as follows. Undissolved impurities of a predetermined particle size are filtered out. Thereafter, the waste water is concentrated and filtered down to a concentrate of a ratio of from about 30/1 to 200/1 while removing excess water and a substantial portion of the remaining impurities and retaining substantially all of the vat dyes and a desired amount of water. The latter step is preferably performed by circulating the waste water through a reverse osmosis filtration device, while separating the waste water into a permeate containing excess water an a substantial portion of the remaining impurities including salts and a concentrate containing substantially all of the vat dyes and a desired amount of water, and by removing the permeate and retaining the concentrate for use in the dyeing operation.

Process for the treatment of ground water

Abstract: Ground water which is high in impurity content such as silica, hardness, sulfates, alkalinity, etc., may be made potable by treating the water with thermal ion exchange desalination resins and a reverse osmosis system. The heat which is present in the ground water is utilized to thermally regenerate the ion exchange resin.

Water purification device and system

Abstract: A water purification unit particularly adapted for household use, and for operation at high pressures, including two main co-operating parts forming a chamber, with a seal positioned between such parts, and a cap compressing the seal and holding the two parts together. The interior of the chamber can contain one or more filtering elements such as a particulate matter filter, a carbon filter or a reverse osmosis filter. To withstand high internal pressures without leakage or damage, mechanical connections are provided within the chamber to form a further positive connection between the two main parts forming the chamber, so as to maintain such filter elements in position within the chamber. A water purification system particularly suitable for household use is provided, incorporating the above unit, wherein tap water is fed to the unit and purified outlet product water is discharged and introduced drop by drop into an open container, affording an aerated storage reservoir of purified water ready for use, and including water overflow means from such container to an outlet drain, the waste water from the water purification unit being also discharged to such drain.

Process for the desalination of salt containing water

Abstract: Water which contains contaminants such as brine may be subjected to a desalination process and made potable thereby by treating the water in a reverse osmosis and ion exchange system, the heat which is present in the water source being utilized to thermally regenerate the ion exchange resin.

Reverse osmosis water unit

Abstract: A portable water container for holding water treated by reverse osmosis water purification, which container rests on a base. The base has a recess in which a reverse osmosis unit is laid, with water connecting means for supplying water to the portable water container and for providing an overflow. The reverse osmosis unit can be quickly and easily removed from the base by merely lifting the osmosis unit from the recess and pulling stopper type end connectors from the ends thereof. The walls of the recessed portion of the base restrains movement of the stopper end connectors from the osmosis units during use. Also a unique reverse osmosis unit is used that has activated carbon impregnated paper therein through which the water passes providing further water treatment.

Reverse osmosis characteristics of composite membranes prepared by plasma polymerization of allylamine. Effects of deposition conditions

Abstract: A study has been conducted to determine the effects of flow configuration and reaction conditions on the performance of composite reverse osmosis membranes prepared by plasma polymerization of allylamine over a porous polymer substrate It was established that superior membranes were obtained by using a gas-flow configuration avoiding direct monomer flow over the substrate High rejections of NaCl could be attained when the plasma-deposited film was sufficiently thick to bridge all of the pores in the substrate It was observed that in addition to influencing the rate of polymerization, the conditions used to sustain the plasma also affected the reverse osmosis characteristics of the deposited film The effects of these conditions and other preparation procedures are discussed Attempts to use infrared spectroscopy and ESCA to identify the relationship between polymer structure and reverse osmosis performance were not successful ESCA did prove useful, though, in confirming an earlier postulated hypothesis that degradation of reverse osmosis performance is associated with the hydrolysis of nitrogen-containing structures in the plasma-deposited film

Desalination reverse osmotic membranes and their preparation

Abstract: Semipermeable membranes useful in reverse osmosis and a process of preparing them comprising deacetylating naturally occurring chitin to produce chitosan, making a film of chitosan salt from an acid diluted aqueous solution of the chitosan, converting the film of chitosan salt to a film of chitosan having free amino groups by neutralizing the acid groups, and then subjecting the film of chitosan to a chemical treatment with an organic acid, by which to convert the chitosan to the acetylated form, having a degree of acetylation from about 0.3 to 0.8, to produce the reverse osmotic membranes. The products have excellent chemical properties as well as mechanical strengths sufficient to withstand the pressure difference in the operating condition.

Process for preparing of semipermeable membranes

Abstract: A method for the preparation of semipermeable membrane which comprises exposing porous shaped articles of polysulfone to a plasma. The resulting semipermeable membrane is very useful for separating substances by reverse osmosis or ultrafiltration.

Processing whey-type by-product liquids from cottonseed protein isolation with ultrafiltration and reverse osmosis membranes

Abstract: Cottonseed wheys resulting from protein isolation from cottonseed flour were processed by semi-permeable ultrafiltration (UF) and reverse osmosis (RO) membranes. The UF membrane fractionated the soluble whey constituents by retaining protein and passing through salts, carbohydrates and other non-protein components along with most of the water. The UF membrane effluent was then processed through an RO membrane to recover a secondary product containing the whey materials not retained in the protein product from the UF membrane. The feasibility of recycling effluent from the RO membrane for reuse in subsequent protein extractions was demonstrated. Thus, the threat of water pollution from effluent disposal could be eliminated completely and process water requirements drastically reduced. Spray-dried UF protein concentrates were tested for utilization in protein fortification of breads and noncarbonated beverages and as whipping products. They exhibited commercial potential for use in these food applications. The economics of processing the whey-type liquids by the membrane process under investigation were analyzed. Membrane processing of wheys by each of two alternative whey processing systems proved to be economically attractive.

Process for manufacturing membranes for osmotic separation

Abstract: An asymmetrical permselective cellulose triacetate membrane has outstanding properties for desalination of seawater by reverse osmosis. It is made by casting a solvent solution of the cellulose triacetate in a solvent mixture of at least 40% acetone, a solvent for the triacetate and a swelling agent for the triacetate. The swelling agent, preferably formamide, must be added as the last component of the solution. After exposing the cast solution to evaporation for 2-90 seconds, it is precipitated in cold water, and then optionally tempered at 50°-100° C. in water which may contain a modifying agent, and dried.