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%.

Provided are direct solvent contact crystallization devices and methods. A direct solvent contact crystallization device can comprises a first liquid-liquid separator comprising an inlet stream comprising 10-35 wt. % salt and a first outlet stream comprising water and a solvent; a second liquid-liquid separator comprising an inlet stream comprising the first outlet stream of the first liquid-liquid separator and a first outlet stream comprising 95 wt. % or greater water; and a separation unit comprising an inlet stream comprising a second outlet stream of the second liquid-liquid separator, a first outlet stream comprising the solvent, and a second outlet stream comprising a recovery agent, wherein the inlet stream of the first liquid-liquid separator comprises the first outlet stream of the separation unit, and the inlet stream of the second liquid-liquid separator comprises the second outlet stream of the separation unit.

An enhanced coagulation method for removing microplastics in water is provided. First, a certain amount of inorganic suspended particles are added to microplastic wastewater to increase the number of particles and thereby improve a collision probability among the particles; and then a natural polymer flocculant and a polysilicic acid are added. The polysilicic acid is used as coagulant aid, so that the three materials can comprehensively achieve the purpose of removing the microplastics in the wastewater. The enhanced coagulation method can combine respective characteristics and advantages of the three materials, so that the three materials can mutually complement each other and give full play to the role of charge neutralization and bridging and net capturing, strengthen the sedimentation performance and enhance the actual microplastic removal effect. Therefore, it is a green and environmentally-friendly enhanced coagulation technology.

A method of water treatment includes providing water that includes at least one contaminant. An effective amount of at least one filter media is added to the to the water that includes at least one contaminant. The water and the at least one filter media are agitated to form a homogeneous mixture. A cationic biopolymer is added to the homogeneous mixture of water and the at least one filter media. The water is separated from the at least one contaminant and the at least one filter media.

Provided are nanonets comprising a) a surfactant aggregate having an average aggregate diameter; and b) a polymer having an average particle diameter which average particle diameter is the same or smaller than the average aggregate diameter, wherein the nanonet has a diameter larger than the average particle diameter. Also provided are kits therefor and methods for sequestering non-water moieties from aqueous solutions using nanonets.

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.

A chitosan-based flocculant has the optimal adjustment of metal salts, alcohols and acids, which allow an all-in-one product to be obtained. A product with compatibility with the main disinfection agents is used in water treatment, which is functional product and is applied in more practical manner, and therefore offers a competitive advantage to end users.

An enhanced coagulation method for removing microplastics in water is provided. First, a certain amount of inorganic suspended particles are added to microplastic wastewater to increase the number of particles and thereby improve a collision probability among the particles; and then a natural polymer flocculant and a polysilicic acid are added. The polysilicic acid is used as coagulant aid, so that the three materials can comprehensively achieve the purpose of removing the microplastics in the wastewater. The enhanced coagulation method can combine respective characteristics and advantages of the three materials, so that the three materials can mutually complement each other and give full play to the role of charge neutralization and bridging and net capturing, strengthen the sedimentation performance and enhance the actual microplastic removal effect. Therefore, it is a green and environmentally-friendly enhanced coagulation technology.

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.

Methods for removing a soluble heavy metal-sulfur complex from a process solution comprise contacting the process solution with an oxidant to oxidize the heavy metal-sulfur complex and form an oxidized complex precipitate, or with an acid to acidify the heavy metal-sulfur complex and form an acidified complex precipitate, and removing the precipitate from the process solution to provide a heavy metal-reduced solution. The method is advantageous for removing heavy metals such as mercury, cadmium, barium, iron, vanadium and/or manganese from process solutions, for example originating from natural gas production, petroleum production, water treatment or mining.