Disclosed are a method for preparing a high-strength anti-pollution anti-bacterial hollow fiber nano-filtration membrane and a product prepared by the method. The method comprises: S1, a chemical crosslinking reaction: placing an ultra-filtration base membrane in an acidic aqueous solution of glucose or an aqueous solution of phytic acid for a chemical crosslinking reaction to obtain a nano-filtration membrane; S2, a neutralization reaction immersing the nano-filtration membrane obtained in step S1 in an aqueous solution of alkali for the neutralization reaction, then washing the membrane to be neutral; S3, loading inorganic antibacterial agent: placing the membrane obtained in step S2 in an inorganic anti-bacterial agent solution for complexation, thereby obtaining a high-strength anti-pollution anti-bacterial hollow fiber nano-filtration membrane.

Electrodeionization apparatuses, systems including a reactor system and an electrodeionization system, and methods of purifying acetic acid are provided herein. In some embodiments, the electrodeionization apparatus includes an anode, and three spaced apart membranes located between the anode and the cathode: a first cation exchange membrane, a first anion exchange membrane, a second cation exchange membrane, defining: a first electrode rinse passage between the anode and the first cation exchange membrane, a first concentrate passage between the first cation exchange membrane and the first anion exchange membrane, a feed stream passage located between the first anion exchange membrane and the second cation exchange membrane, and a second electrode rinse passage between the second cation exchange membrane and the cathode. In some embodiments, the electrodeionization apparatus also includes at least one propionate-selective ion exchange resin wafer within the feed stream passage.

An object of the present invention is to provide an ultrapure water production method and an ultrapure water production system that are capable of suppressing deterioration in a two-stage reverse osmosis membrane device of the ultrapure water production system caused by an oxidant and further suppressing occurrence of biofouling. The ultrapure water production method using an ultrapure water production system including a two-stage reverse osmosis membrane device including a chlorine-resistant reverse osmosis membrane device at a previous-stage and a non-chlorine-resistant reverse osmosis membrane device to perform a treatment at a subsequent-stage, and the method comprises treating a water-to-be-treated having a total of a free chlorine concentration in Cl equivalent and a free bromine concentration in Br equivalent of 0.01 mg/L or more and less than 0.1 mg/L using the chlorine-resistant reverse osmosis membrane device followed by the non-chlorine-resistant reverse osmosis membrane device of the two-stage reverse osmosis membrane device.

The present invention provides nanofiltration membranes with reduced chemical reactivity that can be utilized in manufacturing processes where reactive feedstocks and/or products are utilized or produced. Methods of making and using the membranes are also provided.

The present invention relates to a complete process for preparation of high flux and salt rejection thin film composite (TFC) reverse osmosis (RO) membrane including process for preparation of support membrane for thin film, process for thin film coating of support membrane by in-situ interfacial polymerization between diamines and trimesoyl chloride, machine design, chemistry and details of process (engineering+chemistry+ambient) parameter at 1100 sqm scale upgradeable to a scale even 10-20 times higher. The produced membrane is characterized by 96% salt rejection and 48 LM-2H 1 flux with 2000 ppm sodium chloride solution at 250 psi pressure and 95% salt rejection and 46 LM2H 1 flux with 35000 ppm sodium chloride solution at 900 psi pressure. The present invention also relates to complete machine design for PSF ultrafiltration membrane casting and coating for TFC membrane production at commercial level.

The present invention relates to high performance, crosslinked hollow-fibre membranes and a new process for manufacturing the same.

A dry-process porous membrane having an oxygen induction time (OIT) greater than 3 minutes, greater than 5 minutes, greater than 10 minutes, greater than 15 minutes, greater than 20 minutes, or greater than 25 minutes where OIT is measured at 215? C. and 100% O.sub.2. The dry-process porous membrane may be a microporous polyolefin membrane.

Anion exchange polymers having high OH.sup.? conductivity, chemical stability, and mechanical stability have been developed for use in AEMs. The anion exchange polymers have stable hydrophobic polymer backbones, stable hydrophilic quaternary ammonium cationic groups, and hydrophilic phenolic hydroxyl groups on the polymer side chains. The polymers have polymer backbones free of ether bonds, hydrophilic polymer side chains, and piperidinium ion-conducting functionality, which enables efficient and stable operation in water or CO.sub.2 electrolysis, redox flow battery, and fuel cell applications. The polymer comprises a plurality of repeating units of formula (I) ##STR00001## Anion exchange membranes and membrane electrode assemblies incorporating the anion exchange polymers are also described.

The present invention provides a composite semipermeable membrane which has practicable water permeability and high acid resistance. The present invention relates to a composite semipermeable membrane including a supporting membrane and a separation functional layer disposed on the supporting membrane, in which the separation functional layer includes a crosslinked aromatic polyamide and has a protuberance structure including protrusions and recesses, a proportion in number of protrusions each having a height of 100 nm or larger is 80% or larger in the protrusions of the protuberance structure, and the separation functional layer contains amino groups, carboxy groups, and amide groups and satisfies y/x0.81, in which x is the molar ratio of carboxy groups/amide groups and y is the molar ratio of amino groups/amide groups.

The disclosure provides for polymer membranes which comprise metal organic frameworks, methods of making therein, and methods of use thereof, including in gas separation.