Abstract: A water purification system having a first pressure vessel containing a reverse-osmosis filter and a second separate pressure vessel containing an activated carbon prefilter operatively connected in series and upstream of the first pressure vessel by means of a common header. The activated carbon prefilter includes a particulate trap upstream of the activated carbon to trap sediment carried in the unpurified water. The particulate trap is compressible under operational water pressures attained in the system when the trap becomes clogged with sediment, which serves to crack or break away from the surface thereof particle accumulations clogging the trap, permitting flow to continue through the trap into the activated carbon and, subsequently, through the reverse-osmosis filter element.

Abstract: In a sludge thickener, supernatant fluid is drawn off via peripheral ducts and oxygenated at a suitable location. The supernatant fluid is thereafter reintroduced into the thickener via diffusers distributed transversely of the thickener and intermediate the peripheral ducts. The generation of nauseating smells is thereby prevented, and an advantageous increase of the concentration of the sludges is attained.

Abstract: A cationic charge modified microporous membrane comprising a hydrophilic organic polymeric microporous membrane and a cationic charge modifying agent bonded to substantially all of the wetted surfaces of the membrane, the charge modifying agent being an epichlorohydrin modified polyamide having tertiary amine or quaternary ammonium groups. A secondary charge modifying agent may be employed selected from: (i) aliphatic polyamines having at least one primary amine or at least two secondary amines; and (ii) aliphatic amines having at least one secondary amine and a carboxyl or hydroxyl substituent. Processes for producing and using the membrane are also described.

Abstract: An improved tubular membrane filtration module comprising an outer cylinder and a plurality of water permeable non-woven fabric pipes formed on the inside thereof, said non-woven fabric pipes being inserted into the outer cylinder in a closely bundled state, the spaces between the fabric pipes and the outer cylinder at each end thereof being filled with hardened synthetic resin to fix and seal the assembly and wherein the ends of the non-woven fabric pipes are coated with a resin such that the inside coating of resin at the end of the fabric pipes is less than that on the inside thereof.

Abstract: A blood collection device is provided with a phase partitioning device which includes a standpipe connected to a reservoir filled with a sealant material having a specific gravity intermediate the specific gravities of separated light and heavy phases of blood. Components of the heavy phase of blood enter the reservoir during phase separation and centrifugation to force sealant upwardly in the standpipe and out into the tube above the line of separation.

Abstract: A filter (10) and a method of filtering fluids is provided. In the filter (10), a plurality of porous, hollow fibers (20) surround a central tube (18) and are contained by a housing (12). The ends of the assembly are potted with a sealant to define first and second sealant-impregnated ends (22, 24) having open flow paths through the hollow fibers (20) and central tube (18) from one end to the other. A manifold (16) defining a typically closed chamber covers one end of the assembly and another manifold (14) covers the other end and defines a fluid portal (26) to the tube (18) and hollow fibers (20). Fluid may be filtered by passing it through the pores of the hollow fibers (20) from the outside to the inside and draining fluid from the portal (26). Alternatively, filtering of a fluid may be accomplished by introducing fluid through the portal (26) and passing it through the pores of the hollow fibers (20) from inside to out.

Abstract: A tubular module employed for the separation, purification, concentration, etc., of a solution has a plurality of porous support tubes each containing semipermeable membranes which are arranged parallel in a plurality of stages, and which are fixed at both ends thereof by heads containing return bends so as to connect the porous support tubes into zigzags, and are also tightly fastened together by the centers of the heads by means of a single stay bolt. This tubular membrane module is characterized in that the end of the stay bolt does not extend through the head which is remote from the bolt, but ends within that head, and the return bends within the center of the head are bored so as to be further out than the end of the stay bolt to provide communication between the central tubes, so that the solution in the porous support tubes can be easily removed with no partial vacuum generated therein.

Abstract: Semipermeable membranes of modified polysulfones are provided which comprises repeating units of the formula--M.sub.1 --R.sub.1 --M.sub.2 --R.sub.2 --SO.sub.2 --R.sub.3 --(1)wherein M.sub.1 and M.sub.2 are independently a valence bond, --O-- or --NH--, R.sub.1 is a valence bond or a group of the formula ##STR1## with the proviso that if R.sub.1 is a valence bond, only one of M.sub.1 and M.sub.2 can be --O--, R.sub.2 and R.sub.3 are independently a group of the formula ##STR2## the aryl radicals R.sub.1, R.sub.2 and R.sub.3 are optionally further substituted, R.sub.4 is a valence bond, --O--, alkylene of 1 to 4 carbon atoms optionally substituted or interrupted by cycloalkyl(ene) or aryl(ene) of at most 7 carbon atoms, or alkylidene of 2 to 4 carbon atoms, R.sub.5 to R.sub.10 are independently hydrogen, or --R.sub.11 NH.sub.2, ##STR3## or --R.sub.

Abstract: Semipermeable membranes of modified polysulfones are provided which comprises repeating units of the formula--M.sub.1 --R.sub.1 --M.sub.2 --R.sub.2 --SO.sub.2 --R.sub.3 --(1)wherein M.sub.1 and M.sub.2 are independently a valence bond, --O-- or --NH--, R.sub.1 is a valence bond or a group of the formula ##STR1## with the proviso that if R.sub.1 is a valence bond, only one of M.sub.1 and M.sub.2 can be --O--, R.sub.2 and R.sub.3 are independently a group of the formula ##STR2## the aryl radicals R.sub.1, R.sub.2 and R.sub.3 are optionally further substituted, R.sub.4 is a valence bond, --O--, alkylene of 1 to 4 carbon atoms optionally substituted or interrupted by cycloalkyl(ene) or aryl(ene) of at most 7 carbon atoms, or alkylidene of 2 to 4 carbon atoms, R.sub.5 to R.sub.

Abstract: Fluid separation modules are disclosed having tube sheets positioned in the end portions of the cylindrical shell forming the exterior of the separation module wherein the end portions of the cylindrical shell have been modified in order to provide improved adhesion and fluid seal between the tube sheets and the shell walls.

Abstract: The overall mass transport efficiency of hollow fiber membrane separation cells is increased by introducing segmented flow into the bores of the fibers. The invention is preferably practiced by dispersing a gas segmentation phase into a continuous liquid phase and feeding the dispersion into the bores of the fibers to form alternating flowing segments of gas and liquid.

Abstract: A water treatment or processor device for household use or commercial use (for example, in a restaurant) is provided with fail-safe features in accordance with this invention to shut the treatment device "off" when an element thereof has become ineffective, such as the saturation of an adsorption element or the clogging of a filter element. Once the device is turned "off", it cannot be restarted until the depleted element has been replaced.

Abstract: A method is disclosed for the elimination of hazardous metal wastewater and sludges by recovering the non-ferrous metals zinc, nickel, copper (II), cadmium or chromium (III) present in an aqueous sludge comprising mixed metal hydroxides by selectively precipitating the ferrous metal ions present while maintaining the non-ferrous metal ions in solution, isolating the precipitate and then precipitating the non-ferrous metal ions from solution.

Abstract: A reusable laboratory filter unit having a recoverable filter member. The unit has an upper body or reservoir for receiving the liquid to be filtered and a lower body or receptacle for receiving filtrate. A plate for supporting the filter membrane is captured between the upper and lower bodies when the bodies are joined together. A threaded ring arrangement draws the bodies together axially without rotating one with respect to the other so the membrane is not subjected to any twisting force. Separation of the bodies exposes the support plate so it can be easily removed to recover the membrane.

Abstract: A system is disclosed for the purification of a caustic solution to remove impurities therefrom comprises: bringing the caustic solution into contact under pressure with the outside of a plurality of porous hollow fibers each having at least one open end and coated with a semipermeable membrane and collecting purified solution from the open ends of the hollow fibers. In a preferred embodiment, the filtering medium comprises porous hollow polysulfone fibers coated with a semipermeable sulfonated polysulfone membrane.

Abstract: A system is provided for supplying purified water, without requiring continuous flow of water across the water purification device. A reverse osmosis unit is provided having an unpurified water inlet, a reject water outlet and a product water outlet. The unpurified water inlet is connected to a source of unpurified water. The reject water outlet and the product water outlet are connected to water regulating means. The water regulating means has outlets to drain and to an accumulator tank. When pressure in the accumulator tank is below a predetermined amount, a diaphragm responsive to the pressure operates a pair of spool valves to first automatically direct a first amount of product water only to drain. Thereafter, the spool valves automatically discontinue flow of the first amount of product water to drain and direct the product water to the accumulator tank.

Abstract: A fluid separation module to be mounted in a cylindrical shell and the method of mounting the same, the module including a bundle of hollow fiber membranes and a polymeric tube sheet, the tube sheet being positioned at one end of the bundle of hollow fiber membranes with the hollow fiber membranes extending through the tube sheet. A resilient sheet having the form of the slit tube surrounds the bundle of hollow fibers and is held in this configuration by a plurality of rings encircling the slit tube at spaced intervals thereon, the slit tube being secured to the tube sheet. The rings are moveably mounted on the slit tube in such a manner that, as the module is inserted in the shell, the rings can be manually slid to one end of the slit tube to allow the slit tube to expand into contact with the inner surface of the tubular shell and thereby allow the fiber bundle to open for improved flow of the fluid mixture through the bundle.

Abstract: A process for producing aluminum hydroxide product having an improved level of whiteness is disclosed. In the process, a caustic solution having dissolved aluminum hydroxide is subjected to purification to remove color producing humate material. Purification includes passing the caustic solution through a semi-permeable membrane. The solution purified of humate material is treated to precipitate aluminum hydroxide therefrom.

Abstract: A cationic charge modified microporous membrane comprising a hydrophilic organic polymeric microporous membrane and a cationic charge modifying agent bonded to substantially all of the wetted surfaces of the membrane, the charge modifying agent being an epichlorohydrin modified polyamide having tertiary amine or quaternary ammonium groups. A secondary charge modifying agent may be employed selected from: (i) aliphatic polyamines having at least one primary amine or at least two secondary amines; and (ii) aliphatic amines having at least one secondary amine and a carboxyl or hydroxyl substituent. Processes for producing and using the membrane are also described.

Abstract: Hollow fiber plasmapheresis module and process, said module comprising hollow fibers having cell-retaining pores and an effective length (L) to lumen diameter (D) ratio L/D not greater than 16,400 cm.sup.-1 D (L and D being in centimeters) within a housing having a blood inlet for conducting blood to the fibers, an outlet for conducting exit (plasma-depleted) blood from the fibers, and a plasma outlet for conducting plasma out of the module.