Processes for washing zeolites, preferably less than about 0.5 micron in size, with a microfiltration system employing a washing liquid, such as an aqueous solution or water (preferably deionized water), to produce zeolite crystals having a zeolite pH in the pH range of 9.4 to 10.0 are provided. The zeolite pH is determined by a special procedure. The preferred washing processes include slurring the zeolite crystals with water (or an appropriate wash solution), initially concentrating the slurry...

A filtration apparatus for separating and/or enriching dissolved substances from a suspension or suspensions having at least one filter means through which flow takes place, there being arranged on the retentate side of the filter means a means for producing a shear field which produces a virtually homogeneous shear field and pressure gradient across the inflow cross-section of the filter means. The means for producing the shear field may be formed by a rotationally symmetrical rotor. There may ...

The method of the present invention for separating bacteria includes passing a bacteria-containing liquid through a plural-coated-sintered inorganic membrane on a larger pore size inorganic ceramic support. By plural-coated-sintered is meant at least two sintered coatings of substantially similar pore size. The membrane on a ceramic support preferably includes a porous double-coated sintered ceramic oxide membrane on an alpha-alumina support.

A method and apparatus of purifying feedwater to remove impurities including suspended solids therefrom, the method suitable for using in-line water pressure to permeate water through hollow fiber membranes and to backflush the membranes to remove solids collected or deposited thereon.

A microfiltration membrane is made up dissolving m-phenylenediamine-isophthalic acid copolymer, a high temperature aromatic polyamide, in one or more solvents selected from the group which consists of N-methylpyrrolidone, dimethylformamide and dimethylacetamide, and the resulting solution in the presence of two or more of these solvents, a structure-loosening agent such as water or a polyhydric alcohol, is cast. After gel formation in the film, the latter is washed free from solvents and dried. ...

A microfilter and method for infusion of blood and blood components into premature or neonatal infants designed to be utilized as an interruption filter between the syringe carrying the blood to be transfused and the needle injected into the vein of the patient or stopcock connections to the vasculature of the patient. The filter of this invention includes a filter body adapted to engage a syringe nipple and a needle hub, or standard luer taper fitting. The square body of this filter encases a s...

A method and apparatus for microfiltration useful in softening water as well as in removing other dissolved constituents where the method comprises passing water that contains a precipitate through a semipermeable tubular membrane. Filtrate is received from the outside of the tubular membrane and the filtrate contains levels of dissolved compounds at concentrations below those that would be predicted by the solubility limits of the compounds. The method may be practiced at elevated pressures and...

A method and apparatus of purifying feedwater to remove impurities including suspended solids therefrom, the method suitable for using in-line water pressure to permeate water through hollow fiber membranes and to backflush the membranes to remove solids collected or deposited thereon.

The present invention provides multi-well plates and column arrays in which samples (e.g., cell lysates containing nucleic acids of interest, such as RNA) can be analyzed and/or processed. In one embodiment, the microfiltration arrangement is a multilayer structure, including (i) a column plate having an array of minicolumns into which samples can be placed, (ii) a discrete filter element disposed in each minicolumn, (iii) a drip-director plate having a corresponding array of drip directors thro...

A method and apparatus for microfiltration useful in softening water as well as in removing other dissolved constituents where the method comprises passing water that contains a precipitate through a semipermeable tubular membrane. Filtrate is received from the outside of the tubular membrane and the filtrate contains levels of dissolved compounds at concentrations below those that would be predicted by the solubility limits of the compounds. The method may be practiced at elevated pressures wit...