A filtration method that includes a cleaning step using a chemical agent, wherein provided is the filtration method with excellent chemical resistance performance. The filtration method pertaining to the present invention comprises a filtration step in which a liquid to be filtered is filtered by being passed through a porous membrane formed of a resin, and a cleaning step in which the membrane interior of the porous membrane is cleaned after the filtration step, wherein a porous membrane for which the area ratio of a resin part having an area of 1 μm.sup.2 or less included in a cross section of the membrane interior is at least 70% of the total area of the entire resin part included in the cross section, and said cleaning step includes a step in which an aqueous solution of at least 1% sodium hydroxide is passed through the porous membrane.

A cleaning solution for accelerated cleaning of a membrane having an enzyme and an agent having a pH that is compatible with the enzyme. The cleaning solution may additionally include one or both of a binding agent and a surfactant. Once the cleaning solution has been included in a solution that is used to contact the membrane for a defined period of time, one or both of a binding agent and a reducing agent may be added to the solution that has contacted the membrane. Optionally, one or both of increasing a pH of the solution and increasing a temperature of the solution may be used to reduce an activity of the enzyme.

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.

An automated modular filtration system, particularly for low volume tangential flow filtration processes, comprises a plurality of filtration modules formed as separate assemblies and at least one control unit for jointly controlling filtration processes of individual filtration units. Each filtration module contains at least one individual filtration unit for executing a filtration process independent of the other filtration units, first input ports for receiving a first type of fluids, second input ports for receiving a second type of fluids, and exit ports for outputting unused system fluids. First type fluids are process fluids are specific to the filtration processes executed in individual filtration units. Second type fluids are system fluids not specific to filtration processes executed in the individual filtration units. The second input and exit ports establish inter-module connections so system fluids can be forwarded from one filtration module to an adjacent filtration module of the filtration system.

Provided is a method for manufacturing a long-life brewed alcoholic beverage by a filtration process with the use of a porous membrane involving a washing step, whereby a high tolerance (chemical tolerance) to a washing solution (a chemical solution) and a good filtration performance are achieved. A method for ma manufacturing a second brewed alcoholic beverage which includes: a filtration step for passing a first brewed alcoholic beverage, which contains a yeast and a high-molecular substance or sediment component produced through fermentation by the yeast, through a porous membrane, which is formed of a resin having a three-dimensional network structure, to thereby separate the second brewed alcoholic beverage from the yeast; and a washing step for passing a washing solution through the porous membrane or immersing the porous membrane in the washing solution to thereby wash the inside of the porous membrane.

The present invention provides, in various embodiments, hybrid single-pass tangential flow filtration assemblies, disposable single-pass tangential flow filtration assemblies, scalable single-pass tangential flow filtration assemblies and adaptable modular single-pass tangential flow filtration assemblies. In other embodiments, the invention relates to processes for recovering proteins from the surface of a filtration membrane in a single-pass tangential flow filtration assembly and for cleaning a tangential flow filtration assembly. In additional embodiments, the invention provides methods of increasing the processing capacity of a single-pass tangential flow filtration assembly.

A reverse osmosis treatment device includes: a first pressure vessel for treating an untreated water to produce a primarily treated water and a first permeated water; a second pressure vessel for treating the primarily treated water to produce a secondarily treated water and a second permeated water; a first cleaning solution tank for storing a first cleaning solution for cleaning the first pressure vessel; and a second cleaning solution tank for storing a second cleaning solution for cleaning the second pressure vessel. Each of the first pressure vessel and the second pressure vessel has therein a reverse osmosis membrane element having a reverse osmosis membrane. The first cleaning solution tank is connected to the first concentrate outlet pipe of the first pressure vessel, and the second cleaning solution tank is connected to the inlet pipe for the primarily treated water of the second pressure vessel.

Provided are a cleaning agent and a cleaning liquid that prevent a reduction in the rejection rate of an RO membrane which may occur when the RO membrane is cleaned and a method for cleaning an RO membrane with the cleaning liquid. The agent for cleaning an RO membrane includes a urea derivative. The urea derivative preferably includes urea (H.sub.2N—CO—NH.sub.2) and/or biuret (H.sub.2N—CO—NH—CO—NH.sub.2). The cleaning liquid is an aqueous solution produced by diluting the cleaning agent. The method for cleaning an RO membrane uses the cleaning liquid. Urea and biuret have a structure analogous to amide bonds included in aromatic polyamide RO membranes, and have a strong affinity for amide bond portions. Urea and biuret adsorb onto the amide bond portions, and prevent the amide bonds from being broken by the cleaning liquid.

Components, systems, and methods for producing highly hydrophilitic, functionalized inorganic filtration membranes, pre-treating organic and biological-containing waste waters for minimal membrane fouling and scaling when processed using such functionalized membranes, and use of such functionalized membranes of the present invention in filtration systems for separating such pre-treated waste waters, all with respect to optimal permeate production rates, purity of permeate and resistance to fouling and scale formation on the membranes.

A method for operating a membrane separation device includes (a) setting a flow amount M(t) of permeated water and extracting the permeated water from the membrane separation device by the set flow amount M(t), and (b) temporarily stopping the extracting the permeated water, when a water level of a first water tank in which the membrane separation device is immersed, a water level of a second water tank in communication with the first tank, or a water level of a third water tank receiving overflowing water from the first water tank becomes lower than a predetermined halt water level. M(t), which is the flow amount of the permeated water during a time period t, satisfies a equation M(t)=KQ(t−1), where K is a gain (K>1), and Q(t−1) is an amount of inflow of the water-to-be-treated during a time period t−1 immediately prior to the time period t.