A purification system is for purifying a mixture containing a first solvent, a second solvent, and an impurity. The purification system includes a first membrane separation device including a pervaporation membrane and a second membrane separation device including a filtration membrane. The pervaporation membrane separates the mixture into a first permeated fluid and a first concentrated fluid. The first permeated fluid has a lower concentration of the impurity than that in the mixture, and the first concentrated fluid has a higher concentration of the impurity than that in the mixture. The filtration membrane separates the first concentrated fluid into a second permeated fluid and a second concentrated fluid. The second permeated fluid has a lower concentration of the impurity than that in the first concentrated fluid, and the second concentrated fluid has a higher concentration of the impurity than that in the first concentrated fluid.

A double-layered material consisting of a cellulose nanofibrous (CNF) layer and a graphene oxide (GO) nanolayer coating, wherein the material comprises 0.5-4 wt. % of GO, preferably 1-2 wt. % of GO, in relation to the total weight of the material is disclosed, as well as methods for producing said material, membranes comprising said material, and uses of said material and membranes Thus, the present invention provides a cellulose nanofiber material with a high flux, a good separation performance and a strong mechanical and structural stability in solution.

The invention provides a method for preparing drinking weak alkali water and strontium-rich electrolyte raw water from distilled water obtained in the process of producing salt from well and mine brine, which comprises procedures of pressure reduction treatment, primary filtration, membrane separation treatment, activated carbon adsorption treatment, secondary filtration treatment, sterilization and disinfection treatment and the like on the salt-making distilled water in sequence so as to remove insoluble solid impurities, sulfides, microorganisms and other substances in the raw water, and separate or enrich ions, thereby preparing the weak alkali water suitable for drinking and the strontium-rich electrolyte raw water capable of being used for functional beverage production. The method provided by the invention can not only realize the comprehensive utilization of resources, but also obtain new products, significantly improving the economical efficiency of the process.

A water treatment system 100 includes: a filtration device 16 that includes an RO membrane element 12 and an NF membrane element 14, and treats raw water containing sodium chloride by the RO membrane element 12 and the NF membrane element 14 to generate concentrated raw water; and an electrolytic device 18 that is disposed downstream of the filtration device 16 and electrolyzes the concentrated raw water to generate water containing sodium hypochlorite.

A system for treating a tetraalkylammonium hydroxide-containing liquid having a high-pressure type reverse osmosis membrane device concentrating a liquid to be treated containing tetraalkylammonium hydroxide at a concentration side, and a line for supplying the concentrated liquid to be treated by the reverse osmosis membrane device to an evaporator further concentrating the concentrated liquid to be treated.

Biocide can be controllably added to a feed stream for a membrane. In some examples, the feed stream is separated into a primary feed stream and a secondary feed stream, for example, with the secondary feed stream having a lower flow rate than the primary feed stream. The secondary feed stream may be used to monitor and control the addition of the biocide, which is then diluted when the secondary feed stream is combined with the primary feed stream to form a combined stream for delivery to the membrane.

Water or wastewater filtration processes and systems have a plurality of membrane modules, each having filter media therein, the plurality of membrane modules arranged in parallel fluid flow, a main bottom feed conduit, a main top feed conduit, and separate feed conduits fluidly connecting the main bottom feed conduits and the main top feed conduits to respective membrane modules. A main filtrate conduit, and separate filtrate conduits fluidly connect respective membrane modules to the main filtrate conduit. A backwash conduit fluidly connects the main filtrate conduit to respective membrane modules through the main top and bottom feed conduits. A pump having a pump feed conduit and a pump discharge conduit, the pump discharge conduit fluidly connected to the main top and bottom feed conduits, and a plurality of automatically controllable valves positioned in the main top and bottom feed conduits, the main filtrate conduit, the pump discharge conduit, and the backwash conduit, with a controller configured to actuate the plurality of automatically controllable valves to control feed and backwash flows through the membrane modules using pressure developed only by the pump. The pump is preferably operated by a variable-speed prime mover.

The present disclosure provides a drinking water purification system with a backwashable filter cartridge and a nanofiltration system. The drinking water purification system includes a backwashable pre-filtration unit, a nanofiltration unit and a cleaning unit. The backwashable pre-filtration unit is provided with a backwashable filter cartridge. The nanofiltration unit is provided with a nanofiltration filter cartridge. A water outflow side of the backwashable filter cartridge is connected to a water inflow side of the nanofiltration filter cartridge. The cleaning unit is connected to the water outflow side of the backwashable filter cartridge.

In one or more embodiments, the present invention relates to a method for producing a polyhydroxybutyrate-based resin. The method includes (a) disrupting or solubilizing microbial cells containing a polyhydroxybutyrate-based resin, and (b) separating the polyhydroxybutyrate-based resin from a composition obtained by the process (a). The process (a) and the process (b) use water with a calcium ion concentration (14.5 mg/L or less. The water used in the process (a) and the process (b) is preferably obtained by subjecting wastewater that is discharged from the production process of the polyhydroxybutyrate-based resin to microbial anaerobic and aerobic treatments, subsequently pre-filtration by a membrane bioreactor process, and further filtration with a calcium ion removal membrane This method provides the polyhydroxybutyrate-based resin with good color tone and high thermal stability.

An apparatus for the treatment of wastewater having: a primary treatment module with at least one solids separation filter; a secondary treatment module with at least one microflotation unit and at least one oxidation treatment unit placed downstream of the at least one microflotation unit, the at least one oxidation treatment unit has an advanced oxidation process module for performing chemical processes, the advanced oxidation process module performing an ozone and hypochlorite treatment; a tertiary treatment module including at least one membrane filtration unit; the apparatus provided with sequentially flowing wastewater from the primary treatment module, through the secondary treatment module, and to the tertiary treatment module. A method for wastewater treatment in an apparatus having as sequentially treating wastewater through the primary treatment module, the secondary treatment module, and the tertiary treatment module.