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.

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.

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.

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).

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.

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.

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 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 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.