A method for treating sewage to avoid sludge dumping. The sewage treatment method is a multistage process for sanitizing raw sewage and producing easily managed environmentally safe byproducts. Raw sewage or partially treated sewage is processed to remove and treat any liquids leaving sterilized solids that are compacted for limiting the environmental footprint. The method employs mechanical, thermal, radiation, and chemical treatments to the sewage to produce safe biodegradable materials. The treated final product may be used as fertilizer, fillers, aggregate, or compost.

Activated ferrate solutions, methods of their preparation, and methods of disinfecting surfaces and oxidizing pollutants in water are provided.

A method of treating a sulphate-bearing stream which includes the steps of hydrolysing aluminium sulphate to produce a chemically-reactive aluminium trihydroxide and sulphuric acid, adding lime to immobilize the sulphuric acid as gypsum and using the aluminium trihydroxide to remove sulphate from the sulphate-bearing stream without interference of sulphate derived from the aluminium sulphate used as an aluminium source in the hydrolysis step.

Systems and methods for treating wastewater with an oil-specific viscosifier composition and separating viscosified oil, undissolved solids and/or particulates, and/or other waste materials in such wastewater are provided. The methods further include: providing wastewater that includes oil; mixing the wastewater with an oil-specific viscosifier composition to form a viscosified oil; and separating at least a portion of the viscosified oil from the wastewater to provide treated water.

A water treatment method including a removal step of removing a polymer (I) containing a polymerization unit (I) based on a monomer represented by the following general formula (I) from water containing the polymer (I):

CX.sup.1X.sup.3═CX.sup.2R(—CZ.sup.1Z.sup.2-A.sup.0).sub.m  (I)

wherein X.sup.1 and X.sup.3 are each independently F, Cl, H, or CF.sub.3; X.sup.2 is H, F, an alkyl group, or a fluorine-containing alkyl group; A.sup.0 is an anionic group; R is a linking group; Z.sup.1 and Z.sup.2 are each independently H, F, an alkyl group, or a fluorine-containing alkyl group; and m is an integer of 1 or more. Further, the number average molecular weight of the polymer (I) to 0.3×10.sup.4 or more. Also disclosed is a composition including the polymer (I) containing the polymerization unit (I) based on a monomer represented by general formula (I), and where the composition has a content of the polymer (I) of 250 ppm or less.

Movable thick dehydration device and method for eluent sediment from medium- and low-concentration ammonia nitrogen are provided. The device integrates the existing eluent preparing mechanism, a transferring mechanism, pumping mechanisms, a transport vehicle, an automatic controlling system, an eluent collecting pool, primary and secondary sedimentation pools, and primary and secondary processing units. After post-treatment and recovery of eluent waste from rare earth mines, ammonia nitrogen and rare earth heavy metals in the eluent of rare earth mines can be recovered and disposed, and 90% of ammonia nitrogen and over 95% of rare earth in the eluent can be recycled. The device is movable and automated, and therefore suitable for environmental treatment of closed rare earth mines with residual ammonia nitrogen. Meanwhile, it is beneficial to reduce investment costs of capital construction, disposal site restoration of environmental treatment of rare earth mines with residual ammonia nitrogen.

The invention provides methods and compositions for treating wash water from concrete production with carbon dioxide. The treated wash water can be reused as mix water in fresh batches of concrete.

A system comprising an agitation and flocculation system and a particulate filter capture system, and optionally a feedback system and/or a water softening. The agitation and flocculation system configured to receive a contaminated aqueous stream and an anhydrite quantity, and comprising means for agitating the aqueous stream and a means for mixing the aqueous stream with the anhydrite, such that a precipitate of calcium sulfate hydrate+contaminant complexes is formed. Also, a system comprising a fixed-bed type cross-flow system and a particulate filter capture system, and a corresponding method of removing per- and polyfluorinated alkyl substances from the contaminated aqueous stream. The method comprising the acts of: providing an anhydrite quantity; contacting and agitating the anhydrite quantity with a contaminated aqueous stream; and collecting the precipitate of calcium sulfate hydrate+contaminant complexes formed from the aqueous stream.

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.

Divalent ions are extracted from solids by leaching to form a divalent ion-containing solution. The divalent ion-containing solution is subjected to concentration to form a concentrated divalent ion-containing solution. Precipitation of a divalent ion hydroxide salt is induced from the concentrated divalent ion-containing solution. In other cases, the concentrated divalent ion-containing solution is exposed to carbon dioxide to induce precipitation of a divalent ion carbonate salt.