A method of producing cellulase includes steps (1) to (3): (1) subjecting an aqueous solution of cellulase derived from filamentous fungi to filtration through an ultrafiltration membrane with a molecular weight cut off of 100,000 to 200,000 to obtain a filtrate and concurrently obtain a concentrated enzyme liquid as a retentate; (2) further subjecting the filtrate obtained in step (1) to filtration through a second ultrafiltration membrane with a molecular weight cut off of 5,000 to 50,000 to obtain a second concentrated enzyme liquid as a retentate; and (3) mixing the concentrated enzyme liquid obtained in steps (1) and (2) to obtain cellulase derived from filamentous fungi.

Provided are water treatment systems and methods of treating water that include separating boron and concentrating lithium. For example, described are water treatment systems comprising: a first phase comprising a first plurality of electrodialysis units configured to separate boron from a feed stream, and a second phase comprising a second plurality of electrodialysis units, wherein the feed stream of at least one electrodialysis unit of the second plurality of electrodialysis units comprises an outlet brine stream of at least one electrodialysis unit of the first plurality of electrodialysis units, and wherein the second plurality of electrodialysis units are configured to produce a product brine stream achieving 90-99% lithium recovery.

Concentration control in filtration systems and associated methods are generally described. Streams originating from upstream filters and having similar concentrations of a target minor component and/or similar osmotic pressures can be mixed and subsequently filtered within additional filters. Certain embodiments comprise recycling an output stream produced by a filter to a filter feed stream, wherein the output stream and the filter feed stream have similar concentrations of a target minor component and/or similar osmotic pressures. Such strategic mixing and/or recycling can reduce the amount of energy and/or the amount of filtration medium surface area required to achieve a desired concentration of the target minor component in a final product stream.

A nutrient concentration and water recovery system includes a first suspended solids settling tank configured to receive a flow stream that includes a waste stream with a sludge stream. A first centrifugal pump is coupled to the first suspended solids settling tank. The first centrifugal pump having corrosion resistant wetted parts and variable speed drives to transfer or pressurize process flow streams. A first level transmitter coupled to the first centrifugal pump that provides output signals in response to a level of a process material within the first suspended solids settling tank. The first level transmitter is mounted in the first suspended solids settling tank. A first flow transmitter coupled to the first level transmitter is configured to measure a specific volume of material transferred out of the first suspended solids settling tank. A first pump is coupled to the first flow meter and configured to transfer a flush water that includes suspended solids and inorganics. A vibrating screen is coupled to the first pump. A process tank is coupled to the submersible pump. A sedimentation removal system and a removal device coupled to the sedimentation removal system are provided and configured to remove inorganizes out of a suspension.

The present invention is a method for operating a demineralization apparatus provided with a plurality of demineralizing lines arranged in parallel and having demineralizers, the method comprising passing through some of the demineralizing lines water to be treated to produce demineralized water while passing through another demineralizing line(s) dilute water from a dilute water tank to perform washing of the line(s), and returning water used for said washing back to the dilute water tank, and being characterized by, when the water quality of the dilute water is on the high salts concentration side past a predefined value, discharging part of the dilute water so as to let said part join the water to be treated and providing a new supply of dilute water for replenishment.

A system and method for switching between flows of water solutions passed in groups of blocks of membrane pressure vessels arranged in parallel in a tapered flow system, wherein the system comprises a system inlet feed line, a system outlet flow line, high pressure booster pumps configured to provide a high pressure feed stream to the system; blocks of membrane pressure vessels arrayed in parallel, and a first and second bypass line each parallel to said blocks.

A membrane separation method where a reverse osmosis method can be applied as a method for separating or concentrating a to-be-treated liquid having a high osmotic pressure or as a water recovery method. The membrane separation method for a to-be-treated liquid having an osmotic pressure includes a first step of separating the to-be-treated liquid into a first permeate and a first retentate by a reverse osmosis method using a loose RO membrane (50). The to-be-treated liquid satisfies ?.sub.Cb>?Pmax when an osmotic pressure of a to-be-treated liquid side membrane surface concentration Cb is represented by ?.sub.Cb and a maximum operating pressure difference is represented by ?Pmax, or has an osmotic pressure of 5 MPa or more and 100 MPa or less. The loose RO membrane (50) is a membrane through which at least a part of a solute contained in the to-be-treated liquid passes together with a solvent.

An apparatus separating carbon dioxide from combustion gas using separation membranes, which includes: a first separation membrane in which combustion gas is injected into an inlet side of the first separation membrane; a second separation membrane in which residue gas of the first separation membrane is injected into an inlet side of the second separation membrane; and a third separation membrane in which permeate gas of the first separation membrane is injected into an inlet side of the third separation membrane, wherein at least a part of permeate gas of the third separation membrane is captured, and residue gas of the third separation membrane is injected into the inlet side of the first separation membrane or the second separation membrane. The present invention can be easily applied to an actual process by efficiently separating carbon dioxide using separation membranes.

A process for purify ing a urea-containing aqueous stream, such as the aqueous stream from the recovery section of a urea plant. comprising a step of removing biuret from the urea-containing stream by reverse osmosis in one or more reverse osmosis stages.

Concentration control in filtration systems and associated methods are generally described. Streams originating from upstream filters and having similar concentrations of a target minor component and/or similar osmotic pressures can be mixed and subsequently filtered within additional filters. Certain embodiments comprise recycling an output stream produced by a filter to a filter feed stream, wherein the output stream and the filter feed stream have similar concentrations of a target minor component and/or similar osmotic pressures. Such strategic mixing and/or recycling can reduce the amount of energy and/or the amount of filtration medium surface area required to achieve a desired concentration of the target minor component in a final product stream.