A nonwoven web obtained by electrospinning, suitable for the filtration of nano- and/or submicron aerosols, including a multiplicity of fibers of composition C1, the composition C1 including at least 50% by weight of at least one polymer P1 based on the repeat unit resulting from vinylidene fluoride (VDF), the fibers of composition C1 having a degree of crystallinity in polar phase(s), preferentially in solely beta phase, of at least 65% by weight, with respect to their total weight. Also, a process for the manufacture of the web, to a membrane including the web and also to a process for the washing/sterilization of the web or of the membrane.

A water purification apparatus (1) comprising a RO-device (2) comprising a RO-membrane (2a). The RO-device (2) is configured to receive inlet water to be purified from an inlet path (19) and produce permeate water into a permeate path (22) and reject water into a reject path (23). The apparatus (1) also comprises a recirculation path (24) arranged to recirculate reject water from the reject path (23) to the inlet water. The apparatus further comprises a cooling arrangement (30) comprising a cooling device (31, 39). The cooling arrangement (30) is configured to cool the recirculated reject water in the recirculation path (24) with the cooling device (31, 39), and a control arrangement (40) configured to control the cooling arrangement (30) to cool the recirculated reject water in the recirculation path (24) in order to cool the RO-membrane (2a).

A method for filtering a protein-containing liquid containing protein at a concentration of 20 mg/mL or more and 100 mg/mL or less, the method including a prefiltration step of filtering the protein-containing liquid by a prefilter having a pore size of 0.08 μm to 0.25 μm and including a hydrophobic resin, and a virus removal step of filtering the protein-containing liquid by a virus removal membrane including a synthetic polymer, after the prefiltration step, wherein the protein-containing liquid before conducting the prefiltration step includes 0.25 g or more of a trimer or higher multimer of the proteins having an average diameter of less than 100 nm, per 1 m.sup.2 of the virus removal membrane.

A non-oxidizing, buffered disinfectant concentrate is provided to be included in a solution used to disinfect a membrane. The solution applied to the membrane is configured to have a pH that is compatible with the membrane. The disinfectant concentrate includes an aqueous solvent; a hydrotrope; a strong acid surface cleanser; a biocidal active, preferably, at least two biocidal actives; a buffer agent; and, optionally, an anionic surfactant. The biodical active may be selected to function both as a biocide and as a weak acid/buffer combination. A disinfectant solution applied to the membrane includes from about 0.1 wt % to about 3.5 wt % of this disinfectant concentrate.

A water purifier includes a raw water flow path into which raw water is introduced, a clean water flow path connected to the raw water flow path and having a water discharge nozzle disposed at an end, a filter device disposed in the clean water flow path, and to which a filter is installable to filter the raw water, a drain flow path branched off from the clean water flow path between the filter and the water discharge nozzle and connected to a drain port to drain water in the clean water flow path to outside, a drain valve configured to open or close the drain flow path, and a controller configured to determine a remaining life of the filter on a point in time at which the filter has been replaced and control the drain valve to perform a cleaning operation based on the remaining life of the filter.

The present invention relates to a chemical product and process for cleaning nanofiltration and reverse osmosis membranes, based on enzymatic action aiming to remove biofouling and inorganic scale quickly. The product mentioned in present invention also proposes elimination of the neutralization step of the chemical product used, given that the enzymatic action allows an adequate pH for disposal to be maintained, which fact increases the speed and efficiency of the process.

The invention relates to a method for manufacturing a hollow fiber membrane bundle from a plurality of polysulfone and PVP-based hollow fiber membranes which encompasses the providing of a spinning solution comprising a polysulfone-based material, in particular polysulfone, a vinylpyrrolidone-based polymer, in particular polyvinylpyrrolidone, an aprotic solvent, in particular dimethylacetamide, providing a coagulant liquid comprising water and an aprotic solvent, in particular dimethylacetamide, co-extruding the spinning solution and the coagulant liquid through a concentric annular spinneret into a hollow strand, whereby the cavity of the strand is filled with coagulant liquid, conducting the strand through a precipitation gap, introducing the strand into a precipitating bath comprised substantially of water so as to obtain a hollow fiber membrane, conducting the hollow fiber membranes through at least one rinsing bath and drying the hollow fiber membrane obtained, arranging the resulting hollow fiber membranes into a hollow fiber membrane bundle, and treating the hollow fiber membrane bundle with water vapor.

The invention relates to a respiratory air purifier device. In order to provide an improved respiratory air purifier device which is able effectively to retain viruses, a respiratory air purifier device 101 is proposed for retention of viruses from respiratory air flowing through the device 101, the latter having an interface 110 designed such that it can be placed by a wearer sealingly onto at least one respiratory opening, a hollow-fibre dialyser 120 as a filter, and a connection piece 130 between the interface 110 and the dialyser 120, wherein interface 110, dialyser 120 and connection piece 130 are configured in such a way as to form an airtight fluid channel which fluidically connects the interface to either only the exterior of the hollow fibres X or only the interior of the hollow fibres I of the hollow-fibre dialyser 120, and wherein the purifier device 101 is designed in such a way that, in at least one flow direction E, A, each flow path pE, pA that runs completely through the purifier device extends through the pores of the hollow-fibre membranes, i.e. transversely with respect to the hollow-fibre membrane, of the hollow-fibre dialyser 120.

The present disclosure relates to a water purification apparatus that comprises a reverse osmosis device, RO-device, producing a purified water flow and to a corresponding method. The proposed method comprises detecting at least one fluid property of purified water in the purified water path and regulating a flow rate of water in the recirculation path to fulfill one or more predetermined criteria of the purified water in the purified water path, based on the at least one detected fluid property. The present disclosure also relates to a computer program and a computer program product implementing the method.

A piece of substrate material is formed under heat and pressure against a cavity into a shaped substrate sheet having one or more depressions. Two substrate sheets are bonded together to form a substrate wherein the one or more depressions form one or more interior channels. The substrate, if not formed with pre-coated substrate material, is coated with a dope and quenched to form a filtering membrane. A plurality of membranes may be placed side by side to form a bundle with permeating ends of the membrane, which are open to the one or more interior channels, separated by gaps or spacers. The bundle is connected to a header to produce a module. The module can be assembled into a cassette.