A system for producing magnesium chloride includes a removal unit, and a concentration unit that is connected to the removal unit. The removal unit generates feedstock water by removing sulfate ions and sodium ions from treatment target water having seawater as a feedstock. The concentration unit generates a slurry in which magnesium chloride is crystallized by concentrating the feedstock water. The removal unit has a first removal unit which reduces the sulfate ion concentration compared to the sulfate ion concentration in the treatment target water, and a second removal unit which reduces the sodium ion concentration compared to the sodium ion concentration in the treatment target water.

A water-softening system includes a filter device including filter units that are provided in at least some of a plurality of supply channels arranged in parallel to supply raw water to a consumption site and that remove at least part of ionic matter contained in supplied raw water by electro-deionization and discharge soft water containing less ionic matter than the raw water, a plurality of supply valves provided in the plurality of supply channels to open or close the supply channels, and a processor connected to the filter device and the plurality of supply valves. The processor determines whether water is supplied to the consumption site and controls at least one of the plurality of supply valves to remain open to maintain a state in which water is allowed to be supplied to the consumption site, when it is determined that no water is supplied to the consumption site.

A wastewater recycling system includes a biological reactor having anaerobic, anoxic, and aerobic chambers. A lift station including a pump is operatively connected to the biological reactor. The lift station receives biologically treated liquid from the biological reactor and pumps the liquid from the lift station. A filtration subsystem is operatively connected to the lift station. The filtration subsystem receives and filters the liquid pumped by the lift station. The filtration subsystem includes a salt-rejecting membrane filter comprising a concentrate recirculation conduit operatively connected to recirculate salt-rejecting membrane filter concentrate to a point along the wastewater recycling system upstream of the salt-rejecting membrane filter, thereby forming a salt concentration loop between said point along the wastewater recycling system and the salt-rejecting membrane filter. A post-filtration subsystem is operatively connected to receive salt-rejecting membrane filter permeate, and comprises a water disinfection system that disinfects the permeate thereby generating potable water.

A pure water production method for producing pure water by decarboxylating water to be treated under acidic conditions and then deionizing the result by using a reverse osmosis membrane separation device, the pH of inflow water flowing into the reverse osmosis membrane separation device and the water quality of permeated water of the reverse osmosis membrane separation device being measured, and the pH of the inflow water being adjusted on the basis of the measured pH and water quality so that the water quality of the permeated water is within a prescribed range, wherein the pH of the inflow water is changed by a predetermined width, and an operation condition adjusting step is performed for adjusting the pH of the inflow water by comparing the(average value before the water quality change average value after the water quality change.

Electrodeionization and electrodialysis systems which eliminate or substantially prevent the feed water from entering the concentrating compartments, for improving the recovery of product water as well as improving the current efficiency. Electro-osmotically generated flows of water entering from the diluting compartments of the stack constitutes the majority of concentrate feed, leading to the production of high purity, desalinated waters in the diluting compartments and highly concentrate solutions in the concentrate compartments.

An ion removal device based on electrochemical and photoelectrochemical methods, and the application of energy conversion and storage are provided. In the ion removal process based on the electrochemical and photoelectrochemical fluidization battery device, the positive active material in the flow battery is the positive pole of device, the negative active material in the fluid battery is the negative pole of the device, and the salt solution is the electrolyte in the middle stream. The positive and negative active materials include organic materials such as 4-hydroxy-piperidinol oxide, riboflavin sodium phosphate or methyl viologen, which have the advantages of low raw material cost, environmental friendliness, high sustainability, excellent electrochemical performance, high specific capacity and good cycle stability etc. The electrolyte can be separated from the positive and negative active liquid flow materials according to the fixed sequence of self-assembly of fluid battery mold.

A method and system of providing ultrapure water for semiconductor fabrication operations is provided. The water is treated by utilizing a free radical scavenging system. The free radical scavenging system can utilize actinic radiation with a free radical precursor compound, such as ammonium persulfate. The ultrapure water may be further treated by utilizing ion exchange media and degasification apparatus. A control system can be utilized to regulate a continuously variable intensity of the actinic radiation.

An ocean alkalinity enhancement (OAE) system that reduces atmospheric CO.sub.2 and mitigates ocean acidification by electrochemically processing feedstock solution (e.g., seawater or brine) to generate an alkalinity product that is then supplied to the ocean. The OAE system includes a base-generating device and a control circuit disposed within a modular system housing deployed near a salt feedstock. The base-generating device (e.g., a bipolar electrodialysis (BPED) system) generates a base substance that is then used to generate the ocean alkalinity product. The control circuit controls the base-generating device such that the alkalinity product is supplied to the ocean only when (1) sufficient low/zero-carbon electricity is available, (2) it is safe to operate the base-generating device, and (3) supplying the alkalinity product will not endanger sea life. Modified BPED systems include features that facilitate autonomous system operations including enhanced maintenance cycle operations and a reduced reliance on external fresh water sources.

The present teaching relates to method, system, medium, and implementations for storage management. A hash table is constructed, having an index file having one or more slots, each of which includes one or more buckets. Each bucket stores one or more types of records, including a direct record, an indirect record, and a forwarding record. A direct record stores data directly in a bucket of a slot of the index file. When a storage request is received related to some relevant data, the request is handled based on the constructed hash table.

A resin-wafer electrodeionization (RW-EDI) apparatus for purifying water for coffee brewing comprises a cathode; an anode; and multiple porous solid resin wafer exchange units arranged in a stack between the cathode and the anode, and an air distributor adapted and arranged to aerate the water to be purified. Each unit comprises a monovalent cation exchange membrane (CEM), an anion exchange membrane (AEM), and an ion exchange resin wafer between the CEM and the AEM, which is in contact with, and in fluid flow connection with the CEM and AEM. Each resin wafer comprises a cation exchange resin and an anion exchange resin. The units are oriented with the CEM facing the cathode and the AEM facing the anode, with space between the units defining ion concentrate chambers. Bipolar ion exchange membranes separate the anode and cathode from their nearest resin wafer exchange units.