A filtering device is used for obtaining a chemical liquid by purifying a liquid to be purified and includes an inlet portion, an outlet portion, a filter A, at least one filter B different from the filter A, and a flow path that includes the filter A and the filter B arranged in series and extends from the inlet portion to the outlet portion. The filter A has a porous membrane made of ultra-high-molecular-weight polyethylene and a resin layer disposed to cover at least a portion of the surface of the porous membrane, and the resin layer includes a resin having a neutral group or an ion exchange group.

A filtering device is for obtaining a chemical liquid by purifying a liquid to be purified and has an inlet portion, an outlet portion, a filter A, a filter B different from the filter A, and a flow path extending from the inlet portion to the outlet portion, in which the filter A and the filter B are arranged in series between the inlet portion and the outlet portion and have, and the filter A is selected from the group consisting of predetermined filters A1, A2, and A3.

A filtering device is for obtaining a chemical liquid by purifying a liquid to be purified, and the filtering device has an inlet portion, an outlet portion, a filter A, at least one filter B different from the filter A, and a flow path which includes the filter A and the filter B arranged in series and extends from the inlet portion to the outlet portion, in which the filter A has a porous base material made of polyfluorocarbon and a coating layer which is disposed to cover the porous base material and contains a resin having an adsorptive group.

The analyzing method for quantifying urea in a sample solution includes: a pretreatment step of pretreating the sample solution with at least one of a membrane device including a reverse osmosis membrane and an ion exchange device including an ion exchanger; and an analyzing step of analyzing a target substance in the pretreated sample solution. The analyzing step is based on, for example, flow injection analysis (FIA), and includes a step of quantifying the target substance by measuring the absorbance of a liquid containing a substance generated by reacting the target substance with a reagent.

A method for treating produced water in a system for treating wastewater is disclosed. The system includes a reverse osmosis unit for removing dissolved solids. The reverse osmosis unit produces a permeate and concentrate. To reduce the fouling potential of the membranes associated with the reverse osmosis unit and/or to increase membrane lifetime and/or to increase system recovery, at least a portion of the concentrate is recycled and mixed with the wastewater stream at a point upstream of the reverse osmosis unit.

The present invention relates to the isolation and purification of sialylated oligosaccharides from an aqueous medium in which they are produced.

A platform has a filter system with a first set of filter modules and a second set of filter modules that is different from the first set of filter modules. Each set of filter modules includes an inflow channel and an outflow channel. A fluid inlet is connected to the first set of filter modules, a fluid outlet is connected to the second set of filter modules, and a separation interface separates the first and second sets of filter modules. The separation interface has a first interface channel to connect to the module outflow channel of the first set of filter modules, and a second interface channel to connect to the module inflow channel of the second set of filter modules. The filter system receives fluid through the fluid inlet and, after the fluid has passed through each set of filter modules, discharges the fluid through the fluid outlet.

Provided is a novel Nanofiltration-DiaNanofiltration (NF-DiaNF) system and method for extracting divalent ions from saline water (e.g., seawater) to produce solutions rich in divalent ions (in particular Mg2+, Ca2+ and SO42), while minimizing the concentrations of undesirable species (e.g., Cl, Br, B and Na+). The solutions may be added to water (e.g., desalinated, soft, drinking or irrigation water) to enrich the water with divalent ions, thereby improving its quality.

Provided is a novel Nanofiltration-DiaNanofiltration (NF-DiaNF) system and method for extracting divalent ions from saline water (e.g., seawater) to produce solutions rich in divalent ions (in particular Mg2+, Ca2+ and SO42), while minimizing the concentrations of undesirable species (e.g., Cl, Br, B and Na+). The solutions may be added to water (e.g., desalinated, soft, drinking or irrigation water) to enrich the water with divalent ions, thereby improving its quality.

A purification method for an aqueous hydrogen peroxide solution includes subjecting the aqueous hydrogen peroxide solution to a reverse osmosis membrane separation treatment with a high-pressure reverse osmosis membrane separation device. The high-pressure reverse osmosis membrane has a denser skin layer on the membrane surface and is therefore lower in an amount of membrane permeate water per unit operating pressure but higher in the rejection rate of TOC and boron, as compared with a low-pressure or ultralow-pressure reverse osmosis membrane. The high-pressure reverse osmosis membrane permeate water is preferably further subjected to an ion exchange treatment with an ion exchange device including two or more columns packed with gel-type strong ion exchange resins.