The present invention relates to a water treatment method including: a filtration step of feeding water to be treated to a membrane filtration device having loaded therein a porous separation membrane and performing filtration treatment to obtain filtrate; a discharging step of discharging the water to be treated in the membrane filtration device, which has been separated and concentrated by the porous separation membrane; and a cleaning step of cleaning the porous separation membrane by at least one treatment of physical cleaning and chemical cleaning, in which a cycle including a combination of the filtration step, the discharging step and the cleaning step is repeated multiple times, thereby obtaining filtrate. In each cycle, the filtration step and the discharging step are repeated multiple times, and the cleaning step is then carried out.

A forward osmosis system is provided. The system includes forward osmosis container having a semipermeable membrane dividing the forward osmosis chamber into a first chamber and a second chamber, a draw solution water removal unit including a quantity of draw solution solvent and water, wherein the draw solution solvent includes a nonaqueous liquid and a condenser configured to receive either water vapor or draw solution solvent vapor from the draw solution water removal unit and provide condensed draw solution solvent to the second chamber. The second chamber provides a water diluted draw solution solvent to the draw solution water removal unit. The first chamber takes in received water including a dissolved solute at an input mass per unit of volume and provides a fluid output having an output mass per unit of volume greater than the input mass per unit of volume.

A feed of at least one of (a) a source liquid including a solvent with a dissolved impurity and (b) a retentate of the source liquid is pumped in a substantially closed loop through a liquid-separation module. The liquid-separation module includes a membrane that passes at least partially purified solvent to a permeate side of the membrane while diverting the impurity in a retentate on the retentate side of the membrane. The purified solvent is extracted from the permeate side of the membrane; and the retentate from the liquid-separation module is pumped to or through a pressurized reservoir with a variable volume for the feed component and recirculated as a component of the feed. Over time, the volume for the feed is reduced and the pressure applied to the feed in the reservoir is increased to balance against an increasing difference in osmotic pressure across the membrane.

A method for controlling water purification, and a water purification apparatus (1). The apparatus (1) comprises a reverse osmosis membrane (3a) configured to receive feed water from a feed pump (5), and to produce permeate water and reject water. The method comprises measuring (S1) a property indicative of an inlet water quality C.sub.inlet of inlet water to the feed pump (5), and determining (S2) a target recovery for the water purification based on the property indicative of the inlet water quality. The method further comprises controlling (S3) a feed pump speed to a predetermined speed, or to a speed determined based on a relation between the feed pump speed, the inlet water quality C.sub.inlet and a target permeate water quality C.sub.per, based on the inlet water quality. The method comprises measuring (S4) a property indicative of a product water flow rate Q.sub.prod, wherein the product water is permeate water that is delivered for consumption, recirculating (S5) a first portion of the reject water, and controlling (S6) a drain flow rate Q.sub.drain to drain, from a second portion of the reject water, to accomplish the target recovery based on the product water flow rate Q.sub.prod.

A methane fermentation system which can efficiently generate methane gas is provided. The methane fermentation system decomposes an organic waste with an anaerobic microorganism to cause methane fermentation so as to generate the methane gas. The methane fermentation system includes a wet bead mill which finely pulverizes the organic waste. The methane fermentation system also includes a methane fermentation chamber in which the organic waste finely pulverized in the wet bead mill is decomposed with the anaerobic microorganism to cause the methane fermentation so as to generate the methane gas.

A methane fermentation system which can efficiently generate methane gas is provided. The methane fermentation system decomposes an organic waste with an anaerobic microorganism to cause methane fermentation so as to generate the methane gas. The methane fermentation system includes a wet bead mill which finely pulverizes the organic waste. The methane fermentation system also includes a methane fermentation chamber in which the organic waste finely pulverized in the wet bead mill is decomposed with the anaerobic microorganism to cause the methane fermentation so as to generate the methane gas.

A source liquid including a solvent with a dissolved impurity flows into a reservoir. The source liquid or a concentration of the source liquid is pumped from the reservoir through a pressure exchanger into an upstream side of a liquid-separation module. The module includes a membrane that at least partially purified solvent as filtrate to a permeate side of the liquid-separation module while diverting the impurity in a feed retentate on the upstream side of the liquid-separation module. The substantially pure water is extracted from the permeate side of the liquid-separation module, while the feed retentate is passed from the upstream side of the liquid-separation module through the pressure exchanger, where pressure from the feed retentate is transferred to the feed from the reservoir. The feed retentate is then passed from the pressure exchanger to the reservoir and recirculated as a component of the feed via the above steps.

A source liquid including a solvent with a dissolved impurity flows into a reservoir. The source liquid or a concentration of the source liquid is pumped from the reservoir through a pressure exchanger into an upstream side of a liquid-separation module. The module includes a membrane that at least partially purified solvent as filtrate to a permeate side of the liquid-separation module while diverting the impurity in a feed retentate on the upstream side of the liquid-separation module. The substantially pure water is extracted from the permeate side of the liquid-separation module, while the feed retentate is passed from the upstream side of the liquid-separation module through the pressure exchanger, where pressure from the feed retentate is transferred to the feed from the reservoir. The feed retentate is then passed from the pressure exchanger to the reservoir and recirculated as a component of the feed via the above steps.

Separation methods and systems for converting high concentrations of animal wastes into nutrients and other useful products such as struvite and potassium struvite. Advantageously, the system and methods do not require the addition of external chemicals other than an acid and a base.

The present invention relates to a process for treating aqueous effluents from the primary circuit of a nuclear power plant implementing a separation of boric acid using a reverse osmosis membrane, characterized by the fact that it comprises steps consisting of treating the effluents using a multi-stage assembly composed of reverse osmosis modules comprising a membrane with a high boron rejection rate, arranged in parallel and in series, and recycling of the intermediate products to different points in the assembly.