The present invention relates to a method for the treatment of organic matter, in particular sewage sludge, comprising the following steps: The organic matter is first thickened to increase the solids concentration. The thickened organic matter is supplied directly into a digester. The organic matter is then removed from the digester by way of a recirculation line, thermally treated and returned to the digester. The invention further relates to a device for the treatment of organic matter, in particular sewage sludge, comprising a digester, a thickener and a recirculation line, where the thickener is arranged upstream of the digester, and the recirculation line is designed to supply organic matter from the digester directly to the thermal treatment device, and to return the treated organic matter to the digester.

A process for the treatment of thick fine tailings that include constituents of concern (CoCs) and suspended solids is provided. The process includes subjecting the thick fine tailings to treatments including chemical immobilization of the CoCs, polymer flocculation of the suspended solids, and dewatering. The chemical immobilization can include the addition of compounds enabling the insolubilization of the CoCs. Subjecting the thick fine tailings to chemical immobilization and polymer flocculation can facilitate production of a reclamation-ready material, which can enable disposing of the material as part of a permanent aquatic storage structure (PASS).

Technique to provide an abrasive regeneration method which, from a used abrasive, can recover an abrasive by an efficient method and can thereafter obtain a high-purity regenerated abrasive by a simple method. This abrasive regeneration method uses an abrasive comprising at least one type of abrasive selected from diamond, boron nitride, silicon carbide, alumina, alumina zirconia, zirconium oxide and cerium oxide. The abrasive regeneration involves a slurry recovery step (A) for recovering an abrasive slurry discharged from a polishing machine, a separation and concentration step (B) for adding an alkaline earth metal salt as an inorganic salt to the recovered abrasive slurry to aggregate the abrasive, and separating and concentrating the abrasive from a mother liquor, an abrasive recovery step (C) for recovering the separated and concentrated abrasive, and a second concentration step (D) for filter-treating the concentrated abrasive.

A method of treating process water of a flotation plant is disclosed. The flotation plant comprises a mineral flotation line and a process water circuit for treating underflow and/or overflow of the flotation line. The process water circuit comprises a gravitational solid-liquid separator for dewatering underflow and/or overflow of the mineral flotation line to separate sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material; and a recover water tank for collecting process water. According to the method, prior to leading supernatant from the gravitational solid-liquid separator into the recover water tank, it is subjected to cleaning flotation, in which at least 90% of the flotation gas bubbles have a size from 0.2 to 250 μm, in a cleaning flotation unit. An arrangement for treating process water of a flotation plant, and its use are also disclosed.

A thickener for dewatering fluids having a vessel with a central well extending proximate a top portion of the vessel to a lower cone-shaped portion, a hindered settling zone, and a compressible sediment layer zone within the lower cone-shaped portion. Eductors housed in inlet wells have an inlet nozzle and a mixing tube to receive slurry to be treated and clear fluid to be mixed with the slurry. The fluid from the eductors is directed in counter circular paths via circular chambers situated proximate the inlet wells, such that fluid flowing in each direction collides and forms turbulence within the central well. Resultant fluid is directed into a lamella-type separator circumferentially located about a portion of the central well, having layered fluid paths directed radially outwards from said center longitudinal axis and upwards towards said vessel top portion through a conical, inclined fluid path, plate structure. The eductors are adjustable with a movable iris for limiting the amount of clear fluid exiting the eductor.

A thickener for dewatering fluids having a vessel with a central well extending proximate a top portion of the vessel to a lower cone-shaped portion, a hindered settling zone, and a compressible sediment layer zone within the lower cone-shaped portion. Eductors housed in inlet wells have an inlet nozzle and a mixing tube to receive slurry to be treated and clear fluid to be mixed with the slurry. The fluid from the eductors is directed in counter circular paths via circular chambers situated proximate the inlet wells, such that fluid flowing in each direction collides and forms turbulence within the central well. Resultant fluid is directed into a lamella-type separator circumferentially located about a portion of the central well, having layered fluid paths directed radially outwards from said center longitudinal axis and upwards towards said vessel top portion through a conical, inclined fluid path, plate structure. The eductors are adjustable with a movable iris for limiting the amount of clear fluid exiting the eductor.

Disclosed is a method for thickening or dehydrating sludge, which includes at least: a) a step of adding flocculants to the sludge to be treated; b) a step of flocculation by agitation of the sludge with the flocculants thus added in order to form a mixture of flocks and an aqueous solution; c) a step of mechanical separation of the flocks and the aqueous solution formed during the preceding step; d) a step of recovering the aqueous solution and the flocks that make up a treated sludge; wherein: the added flocculants are made up of at least one cationic starch (S) and at least one cationic polyacrylamide (P); the cationic starch or starches (S) including a fixed weight percentage of nitrogen of at least 2%; and the weight ratio (R) w.sub.s/(w.sub.s+w.sub.p), expressed as solids, is included between 0.6 and 0.99.

Disclosed herein are processes for treating high-P fluid involving (1) providing a high-P containing stream; (2) chemically treating the high-P stream such that a majority of dissolved P in the stream is transformed into a solid form via sorption of P onto particles placed or precipitated within the stream; and (3) removing the solid form containing P from the chemically treated fine solids stream, such that >about 90% of the total P is removed from the high-P fluid. Also disclosed are systems for treating a high-P stream, the systems involving (1) a chemical treatment station operable to chemically treat and transform equal to or greater than about 90% of dissolved P in a high-P stream into a solid form; and (2) a liquid-solid separator station operable to remove the solid form containing P from the chemically treated high-P stream.

The present disclosure relates to a method for treating and recycling, in an environment-friendly manner, sludge and waste water generated in a process for crushing waste concrete and recycling waste concrete into aggregates. Sand is separated from sludge configured from cement components and sand components and is recycled as fine aggregates, and the cement components can be used as concrete admixtures. Furthermore, the present invention introduces a mineral carbonation technique and thereby allows pH of waste water to satisfy an environmental standard and allows high value calcium carbonate to be produced.

Methods to improve dewatering in industrial and municipal sludges are described. One method involves admixing sludge from a papermaking process and modified cellulose to provide modified sludge with the modified cellulose present in an effective amount to improve dewatering in the treated sludge, such as in allowing use of reduced amounts of coagulant and/or reducing dewatering times, increased dewatered volumes, and reduced sludge product moisture contents, and the like. The dewatered sludge may be formed into a dried particulate, and may be used as filler or other component of concrete, rubber, asphalt, plastics, resin-wood composite products, and other composite products.