A struvite and a method for extracting the struvite from seawater, concentrated salt water or brine. NH.sub.4HCO.sub.3 and H.sub.3PO.sub.4 are added in the seawater, concentrated salt water or brine, and NH.sub.4HCO.sub.3, H.sub.3PO.sub.4 and the seawater, concentrated salt water or brine are stirred and well mixed to react. Then electromagnetic ionic liquid are dripped, with a dripping time controlled to be 30 to 50 min and pH value of the reaction solution to be within a range of 7.5 to 8.5, to generate white precipitate. Finally, the white precipitate is separated from the liquid, spin dried and packaged to obtain the struvite. The struvite has higher purity and fertilizer efficiency than natural struvite, and also contains potassium, calcium, sulfur and chlorine required for crop growth and dozens of types of trace elements such as molybdenum, zinc, manganese, iron, copper and selenium, which is more suitable for the crop growth.

The present invention relates to a process for removing dissolved silica from a high pH brine produced by an evaporator employed in treating a waste stream. The high pH brine is directed to a crystallizer reactor and an acid or CO.sub.2 is mixed therewith to reduce the pH of the brine, causing the silica in the brine to precipitate. The brine is then directed to a first solids-liquid separator which produces a slurry containing the precipitated silica. The slurry is split into first and second streams with one stream recycled to the crystallizer reactor while the other slurry stream is directed to a second solids-liquid separator which produces a wet cake containing the silica solids.

In a process for treating wastewater from a combined gasification and Fischer-Tropsch (F-T) process, feedstock derived from Municipal Solid Waste or the like is gasified in a reactor (R) and treated in a cleanup unit (C) which generates a first wastewater stream (1st WWT STREAM) containing salts and inorganic pollutants. The first wastewater stream is treated in a treatment unit (T1) to remove inorganic pollutants derived from the syngas. The treatment comprises a) degassing, and subsequently b) neutralising the first wastewater stream before treatment in a Dissolved Air Flotation unit (72c) and filtering in a moving sand bed or similar (72d) to remove solids, and a stripping process to remove ammonia. A second wastewater stream (2.sup.nd WWT Stream) containing organic pollutants but being low in salts arises from the F-T process and is treated separately to allow recycling within the F-T process.

The invention concerns a flocculation formulation. The invention also concerns the treatment of mine tailings in the form of aqueous effluents comprising solid particles. With the method of the invention, it is possible to separate all or part of the water from an aqueous effluent comprising solid particles.

A method for treating tailings substrate from mining or oil sands separation process, the tailings substrate comprising an aqueous phase with suspended solid particulate material. In the method, a flocculating agent is added to the tailings substrate, flocs are allowed to form and the formed flocs are separated from the aqueous phase. The flocculating agent comprises a degraded polyacrylamide comprising at least anionic units and having a process water viscosity reduced by 25-99%, preferably 50-99%, compared to a substantially similar polyacrylamide that has not been degraded by a degradation agent, measured at a shear rate 1 s.sup.−1 as a 0.4-0.8 weight-% solution of polymer in process water.

Disclosed is a rake-free thickening device including driving area. The device includes a feed assembly, a diversion assembly and a clean coal collection assembly. The clean coal collection assembly includes a driving area. The diversion assembly includes a central tank. Slime water passes through the feed assembly and flows with a medicament from an upper part of the central tank to a middle of the central tank, and then diffuses around. Bubbles carry the fine slime up after reacting. The driving zone drives the dispersed bubbles to a defoaming zone located in the middle of the central tank. The slime water in the central tank flows through the central tank after defoaming. With the continuously filling of slime water, the slime water above the central tank overflows the central tank to the clean coal collection assembly within the diversion and settlement area.

Methods for removing polymers from treatment fluids for use in subterranean formations are provided. In one or more embodiments, the methods include providing a treatment fluid comprising an aqueous base fluid and a polymer comprising polyvinylpyrrolidone or a derivative thereof; and adding a precipitant to the treatment fluid to form a precipitate with at least a portion of the polymer.

Methods and systems are disclosed for optimization of coagulation and/or flocculation in a water treatment process. According to exemplary embodiments, samples are taken from an aqueous liquid and the samples are monitored with an imaging device to capture visual data of particles dispersed or suspended in the liquid. The particles are classified into particle types based on the visual data and a particle size distribution indication is computed for each classified particle type. The particle size distribution indication is then compared to a predetermined particle size distribution value, and in response to a difference detected, dosage of at least one coagulation and/or flocculation agent in the water treatment process can be adjusted.

This invention provides a method for efficiently separating magnesium and lithium from salt lake brine, and simultaneously preparing high-purity magnesium oxide and battery-grade lithium carbonate. The detailed processing steps are as follows: (1) adding urea into the brine to dissolve, (2) placing the solution into the reactor for hydrothermal reaction, the magnesium ion will precipitate and enter the solid phase; (3) filtering and drying the production to get the magnesium carbonate solid, while the lithium ion remains in the liquid phase; (4) after directly concentration and precipitation, the battery-grade lithium carbonate can be obtained, while the calcination of solid-phase product results in the high-purity magnesium oxide. In this method, urea is used as the precipitant to separate magnesium and lithium in salt lake without introducing any new metal ion, and the brine solution is not diluted. The solid product is white and fluffy powder, which is easy to filter and separate. The extraction rate of lithium is high than 94%, and the purity of MgO obtained by calcination is higher than 99.5%.

The present disclosure relates to a method of flocculation, wherein harmful cyanobacteria are flocculated via metal-organic framework, and wherein the metal-organic framework comprises chromium, which is environmentally friendly. Water-stable Cr(III)-based MOFs, structured as NH.sub.2-MIL-101, remove harmful algal blooms, such as Microcystis aeruginosa, from natural water sources by promoting flocculation. NH.sub.2-MIL-101(Cr) MOFs efficiently remove harmful algae from water without creating secondary pollution and without causing the harmful algae to release intracellular toxins.