A method includes: (1) using a chelating agent, extracting divalent ions from a brine solution as complexes of the chelating agent and the divalent ions; (2) using a weak acid, regenerating the chelating agent and producing a divalent ion salt solution; and (3) introducing carbon dioxide to the divalent ion salt solution to induce precipitation of the divalent ions as a carbonate salt. Another method includes: (1) combining water with carbon dioxide to produce a carbon dioxide solution; (2) introducing an ion exchanger to the carbon dioxide solution to induce exchange of alkali metal cations included in the ion exchanger with protons included in the carbon dioxide solution and to produce a bicarbonate salt solution of the alkali metal cations; and (3) introducing a brine solution to the bicarbonate salt solution to induce precipitation of divalent ions from the brine solution as a carbonate salt.

An ionic liquid and a forward osmosis process employing the same are provided. The ionic liquid has a structure represented by Formula (I)

AB.sub.n   Formula (I)

, wherein A is

##STR00001##

n is 1 or 2; m is 0, or an integer from 1 to 7; R.sup.1 and R.sup.2 are independently methyl or ethyl; k is an integer from 3 to 8; B is

##STR00002##

i is independently 1, 2, or 3; and j is 5, 6, or 7. The forward osmosis process employing the ionic liquid is used to desalinate a brine via a forward osmosis (FO) model.

The present invention relates to a system and a method for abating the presence of a selected chemical substance in wastewater flowing in a wastewater channel system from an upstream position to a downstream position. The method typically comprising dosing into the wastewater, at the upstream position, chemical agent(s) adapted to abate the presence of said selected chemical substance, wherein the dosing is in an amount set by a dosing set-point, and adjusting the dosing set-point based on determinations of the concentration of the selected chemical substance at the downstream position. The invention involves comparison between a determined concentration and a pre-selected fractile and adjusting a dosing set-point based thereon.

A method for producing a metal nanoparticle-loaded biopolymer microgel involving the reduction of metal ions in a metal ion-loaded biopolymer microgel. The method yields a metal nanoparticle-loaded biopolymer microgel. Also disclosed is a method of catalytically reducing an organic pollutant in water using the metal nanoparticle-loaded biopolymer microgel and a reducing agent.

Systems and processes for producing potassium sulfate that include providing an industrial waste material that includes at least sodium sulfate, reacting the sodium sulfate with potassium chloride to produce a byproduct comprising potassium sulfate and a chloride-containing brine, and reacting the chloride-containing brine with barium chloride to produce barium sulfate and sodium chloride.

A method for producing a metal nanoparticle-loaded biopolymer microgel involving the reduction of metal ions in a metal ion-loaded biopolymer microgel. The method yields a metal nanoparticle-loaded biopolymer microgel. Also disclosed is a method of catalytically reducing an organic pollutant in water using the metal nanoparticle-loaded biopolymer microgel and a reducing agent.

A method for desalinating a brine includes the use of a cooled intermediate-cold-liquid (ICL), which combines with the brine in a crystallization or freezing tank to produce a slurry of ice, brine, and ICL. The method includes steps for separating the ICL, ice and brine, and returning the separated ICL to the source of cooled ICL tank. The method concludes with the steps of passing the separated brine to the crystallization tank, and melting the separated ice to form desalinated water. The method is significant in that it produces desalinated liquid water and solid salts. The combination of superior heat transfer with high quality purified water and competitive desalination economy makes the disclosed freeze desalination technology an attractive solution for desalination of highly concentrated brines produced in a variety of industries, including but not limited to the oil and gas industry and reject brine management.

A method may add whey to high calcium papermaking industrial wastewater blended and pre-acidification treatment to promote anaerobic reaction and inhibit calcification. The method includes, before anaerobic treatment of papermaking wastewater, mixing whey wastewater with the papermaking wastewater. The method also includes pre-treating the papermaking wastewater by acidification to stabilize the papermaking wastewater prior to entering an anaerobic reaction system.

The invention relates to a method and an assembly for recovering magnesium ammonium phosphate from slurry that is supplied to a reaction container (10) in which an aerobic milieu is present and in which the slurry is guided in a circuit with the aid of ventilation. Cationic magnesium, such as magnesium chloride, is added to the slurry, and magnesium ammonium phosphate crystals which are precipitated from the slurry are removed via a removal device (30) provided in the base region of the reaction container. Substances which contain magnesium ammonium phosphate crystals collected in the removal device (30) are loosened and/or rinsed.

To promote anaerobic digestion and delay calcification, one or more signal molecules are used to regulate the microenvironment of anaerobic granular sludge. In the process of anaerobic granular sludge treatment of papermaking wastewater, AHLs (N-acyl Hyperserine Lactones) are added to papermaking wastewater before the papermaking wastewater enters the anaerobic reactor. This may occur when the proportion of microorganism in anaerobic granular sludge VSS/TSS is less than 0.6. Further, the addition of the one or more signal molecules changes the community structure of the bacteria and methanogens, promoting anaerobic digestion and delay calcification. Additionally, the microenvironment of granular sludge is regulated by adding one or more micro-signal molecules to improve the number of bacteria susceptible to calcification, improve the anaerobic digestion rate of sludge that has not been calcified, and delay the calcification rate.