A waste stream is treated by anaerobic digestion. A process is described involves a step of separating solids from digestate, and returning separated solids to a digester. Optionally, there may be a step of solids separation in which larger solids are removed from the digester. A process and apparatus are described for treating waste sludge from a wastewater treatment plant in an anaerobic digester. Feed sludge is thickened or solids are separated from digestate and returned to the digester. Additional co-digestion waste may be added to the digester. The process and apparatus may be used in a retrofit of an existing wastewater treatment plant.

A sludge treatment system, comprising a pump (1), an ozone generation device, an ejector (2) and pipe reactors (3). The pump (1), the ozone generation device, the ejector (2) and the pipe reactors (3) are sequentially connected by pipes. An oxygen generator (4) and an ozone machine (5) are arranged within the ozone generation device, and are connected by a pipe. The ozone generation device is used for providing ozone into the pipe reactors (3). The inner surfaces of the pipe reactors (3) are coated with a catalyst layer used for increasing the oxidative capacity of the ozone on the sludge. Spiral fin plates (6) allowing a fluid to generate a spiral flow are arranged within the pipe reactors (3). Also disclosed is a sludge treatment method using the present sludge treatment system. The present system has a high ozone utilization rate, and a low ozone input proportion.

A sludge treatment system, comprising a pump (1), an ozone generation device, an ejector (2) and pipe reactors (3). The pump (1), the ozone generation device, the ejector (2) and the pipe reactors (3) are sequentially connected by pipes. An oxygen generator (4) and an ozone machine (5) are arranged within the ozone generation device, and are connected by a pipe. The ozone generation device is used for providing ozone into the pipe reactors (3). The inner surfaces of the pipe reactors (3) are coated with a catalyst layer used for increasing the oxidative capacity of the ozone on the sludge. Spiral fin plates (6) allowing a fluid to generate a spiral flow are arranged within the pipe reactors (3). Also disclosed is a sludge treatment method using the present sludge treatment system. The present system has a high ozone utilization rate, and a low ozone input proportion.

The invention relates to a method for preparing a dry cationic hydrogel polymer product. The method comprises polymerisation of a reaction mixture comprising ethylenically unsaturated monomers in presence of water and initiator(s) by radical polymerisation and obtaining a hydrogel polymer. The hydrogel polymer is comminuted by chopping or shredding, and dried, whereby a dry hydrogel polymer product in powder form is obtained. At least one cationic reverse phase emulsion polymer is added to the hydro polymer at the comminuting step. The invention relates also to a dry cationic hydrogel polymer composition prepared by the method and its use.

The improved process for conditioning sludges by flocculation, according to which: the sludge to be treated is transported in a pipeline, at least one flocculating agent is inserted in the pipeline that transports the sludge to be treated, the sludge is then mixed with the said flocculating agent. finally, the mixture is transported and then discharged in a natural or an artificial excavation at a distance from the bottom of the said excavation that is less than its depth.

A mineral recovery system for use in a mining operation is described. The mineral recovery system includes a mining operations model generated based on inputs of sensed conditions, wherein the mining operations model incorporates a thickener sub-model and a material sub-model. The mineral recovery system includes a thickener controller to issue commands based on the mining operations model. The mineral recovery system includes a thickener having a process water. The thickener also includes an underflow output provided with an underflow controller to adjust outflow of thickened slurry from the thickener based on issued commands. The thickener further includes an overflow output to dispense clarified water from the thickener.

A method, system and composition is described for treating waste generated from manufacturing operations including at least one of Printed Circuit Boards Fabrication (PCB FAB), General Metal Finishing (GMF), semiconductors manufacturing, chemical milling, and Physical Vapour Deposition (PVD). The method, system and composition are used to create zero liquid discharge recycling.

A portable waste treatment apparatus for treating hydro-excavation waste includes an elongate frame formed from separable upper and lower frame sections mounted upon one another. The upper frame section houses a mixing tank for receiving waste slurry and for mixing the waste slurry with flocculating and/or coagulating agents. A thickener tank receives waste slurry from the mixing tank, and a dewatering device is provided for dewatering sludge collected in the thickener tank. The lower frame section houses a buffer tank arranged to receive sludge from a sludge outlet of the thickener tank. A pump is provided for pumping the sludge to the dewatering device, and a water tank is arranged to receive water overflowing from the thickener tank.

A method of processing pulp, extracted from red mud in processing bauxite, includes the following steps. The pulp is filtered to obtain a first filter cake and a first filtrate. Aluminum is leached from the first filter cake by adding, to the first filter cake, sodium hydroxide (NaOH) solution to form an aluminum-containing first slurry. The first slurry is filtered to obtain an aluminum-containing second filter cake and a second filtrate. From the second filtrate, in presence of carbon dioxide gas, first aluminum compounds are filtered out. Aluminum is leached out from the second filter cake by adding, to the second filter cake, NaOH solution to form a second slurry. The second slurry is filtered to obtain a third filter cake and an aluminum-containing third filtrate. From the third filtrate, second aluminum compounds are precipitated out which include sodium hydroaluminocarbonate and aluminum hydroxide.

An industrial waste salt resourceful treatment method comprises the following steps: the industrial waste salt is sequentially subject to dissolving, chemical pre-purification, deep purification, organic matter concentration reduction, adsorption and oxidation decolorization and multi-effect evaporative crystallization to respectively obtain sodium sulfate, sodium chloride and sodium nitrate crystals; the crystallization temperature of sodium sulfate is in a range of 75° C. to 85° C.; the crystallization temperature of sodium chloride is in a range of 60 to 70° C.; and the crystallization temperature of sodium nitrate is in a range of 45° C. to 55° C. An industrial waste salt resourceful treatment device is further provided.