Abstract: The invention provides permeable magnetically responsive filtration membranes that include a filtration membrane polymer base suitable for fluid filtration; hydrophilic polymers conjugated to the surface of the filtration membrane polymer; and magnetic nanoparticles affixed to the ends of a plurality of the hydrophilic polymers, wherein the hydrophilic polymers are movable with respect to the surface of the filtration membrane polymer surface in the presence of an oscillating magnetic field.

Abstract: The invention provides permeable magnetically responsive filtration membranes that include a filtration membrane polymer base suitable for fluid filtration; hydrophilic polymers conjugated to the surface of the filtration membrane polymer; and magnetic nanoparticles affixed to the ends of a plurality of the hydrophilic polymers, wherein the hydrophilic polymers are movable with respect to the surface of the filtration membrane polymer surface in the presence of an oscillating magnetic field.

Abstract: An aeration device disperses microbubbles into a liquid and maintains efficient transfer of gas to the liquid. The aeration device uses a number of sealed end, hollow fiber membranes that are hydrophobic and provided with pores in the walls of the tubular fibers that range from about 0.01 to 1.0 microns, so that very small bubbles are formed on the outside surface of the hollow fiber membranes. Gas pressures above the bubble point of the fiber membranes are used, and a cloud of microbubbles is expelled into the liquid as it is forced to flow past the fibers. These microbubbles provide a large surface area for the effective dissolution of gases into the liquid. The length of the hollow fiber membranes is controlled in order to obtain efficient small bubble formation.

Abstract: A gas transfer device is used to transfer gas directly into a liquid without the formation of bubbles through a plurality of elongated tubular fibers having membrane walls. A portion of each fiber consists of a thin, smooth, hydrophobic, non-porous, gas permeable polymer which prevents bubble formation and inhibits the accumulation of debris and microorganisms on the outside surface of the membrane walls. The fibers have an open end connected to a regulated gas supply and a sealed end to obtain 100% gas transfer efficiency. A second portion of each fiber is wetted to result in transfer of condensate from the interior of the fibers to the exterior to provide for a continuous operation of the gas transfer device.

Abstract: Contaminated water is pumped through hollow fiber membranes of microporous polypropylene with a very thin outside coating of plasma polymerized disiloxane. The fibers are potted in a module which resembles a shell and tube heat exchanger. Strippant is pumped through the shell side of the module and over the outside of the fibers. The volatile and semi-volatile contaminants in the water diffuse across the membrane and dissolve into the oil. The process results in clean water and a smaller volume of more highly contaminated oil.

Abstract: A method for recovery of metal and cyanide from plating baths and rinse waters includes formation of hydrogen cyanide by acid treatment of such solutions, followed by HCN removal through diffusion across a microporous membrane. The method is applicable in a system wherein soluable metal cyanides and metal cyanide complexes are concentrated through use of a basic anion exchange system. Free hydrogen cyanide is released from the anion exchange system by means of an acid regenerant. In a preferred application of the invention, HCN, once having diffused through the microporous membrane, is neutralized with sodium hydroxide, to form a sodium cyanide solution that can be returned to a plating bath.

Abstract: A process for treating wastewaters to reduce the ammonia content thereof comprising the steps of:A. contacting wastewater, having a dissolved ammonia content, with an ion exchanger having an affinity for ammonium ions whereby ammonium ions become sorbed onto said ion exchanger;B. separating said ion exchanger containing sorbed ammonium ions from the wastewater and then regenerating said ion exchanger and converting the ammonium ions thereon to nitrate ions by treating the ion exchanger with a concentrated salt solution and a culture of nitrifying bacteria whereby ions from the salt solution become absorbed onto the ion exchanger while ammonium ions on the ion exchanger are displaced into solution and oxidized by the nitrifying bacteria to nitrate ions; and,C. recycling the regenerated ion exchanger for further contact with wastewater.