The invention concerns a subsea water processing system comprising an electrochemical unit that uses raw or treated seawater to generate high pH and low pH solutions that are used to clean at least one subsea process apparatus during a cleaning cycle by circulation through the at least one subsea process apparatus via acid or base flow lines connecting the electrochemical unit with the subsea process apparatus on-site.

A germ barrier is provided in the concentrate/wastewater drain from a water installation system towards the wastewater sewer in order to prevent backward contamination with germs, using a UV lamp or a chemical germ barrier that contains an alkaline material, in particular a material selected from the group consisting of carbonates, oxides, and peroxides, and combinations thereof.

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.

A composition for cleaning membranes used in food processing comprising an amine oxide and an alkyl sulfate, the composition maintaining good cleaning performance whilst leaving a low residue of surfactant on the membrane that is cleaned using the composition. A method of use of the composition is also presented.

The disclosure pertains to sanitizing the permeate flow path of a reverse osmosis system. A method of sanitizing a filtration system is disclosed that can include injecting a biocide into a permeate compartment of an operating reverse osmosis system. The method can also include maintaining pressure in a concentrate compartment of the reverse osmosis system simultaneously while injecting the biocide.

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 m.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.

Provided are a filter device and a washing method therefor. The filter device comprises a membrane housing (1); a spacer (2) having an ion transmittance and separating the membrane housing (1) into a first chamber (11) and a second chamber (12); a membrane element (6) disposed in the first chamber (11); a first electrode (4) disposed in the first chamber (11); and a second electrode (5) disposed in the second chamber (12). The method comprises respectively connecting a positive electrode and a negative electrode to the first electrode (4) and the second electrode (5), such that the first electrode (4) and the second electrode (5), water in the first chamber (11) and water in the second chamber (12) form an electrolytic cell, thus generating acidic water or alkaline water in the first chamber (11). The acidic water and/or the alkaline water are/is used for washing the member element.

A composition for cleaning membranes used in food processing comprising an amine oxide and an alkyl sulfate, the composition maintaining good cleaning performance whilst leaving a low residue of surfactant on the membrane that is cleaned using the composition. A method of use of the composition is also presented.

Provided is a method for cleaning a filtration membrane provided in a membrane filtration device that is immersed in a liquid to be treated and performs solid-liquid separation on the liquid to be treated. When a transmembrane pressure difference exceeds a first predetermined pressure difference P1, a first cleaning step W1 for cleaning a filtration membrane is performed using a first chemical solution; when the transmembrane pressure difference immediately after performing the first cleaning step W1 exceeds a second predetermined pressure difference P2 that is lower than the first predetermined pressure difference, a second cleaning step W2 for cleaning the filtration membrane is performed using a second chemical solution having a concentration higher than the first chemical solution; and when the second cleaning step W2 is performed, the concentration of the second chemical solution and/or the cleaning time is changed according to the temperature of the liquid to be treated.

A method of producing a sugar liquid includes a step of filtering a saccharified liquid derived from cellulose-containing biomass, through a nanofiltration membrane and/or reverse osmosis membrane; and a two-step washing step of washing the nanofiltration membrane and/or reverse osmosis membrane after the filtration, with an acid washing liquid and then with an alkali washing liquid; is provided. The method of producing a sugar liquid in which a cellulose-derived sugar liquid is processed through a nanofiltration membrane and/or reverse osmosis membrane is/are effectively washed in a contaminated separation membrane(s).