A flocculation and sedimentation apparatus has: sedimentation tank that causes flocs in raw water to be sedimented and separated; sludge concentration tank that is surrounded by sedimentation tank and that collects and concentrates the flocs; and raw water supply mechanism having center line that passes through sludge concentration tank, wherein raw water supply mechanism rotates about center line and supplies the raw water to sedimentation tank. Raw water supply mechanism includes: raw water introducing portion that is located on center line and to which the raw water is introduced, raw water supply port that is open at a lower portion of an inner space of sedimentation tank and that supplies the raw water to sedimentation tank, and pipe portion that communicates both with raw water introducing portion and with raw water supply port and that extends above sludge concentration tank in a direction away from center line.

Provided is a mixing/clarifying device 100 including a coagulant feeder 10 that feeds coagulant to water to be treated to obtain coagulant-containing water and a tank 20 in which the coagulant-containing water is mixed to form a floc and solid-liquid separation is performed. The tank 20 includes an outer cylinder 21 having an inflow port 210 that flows the coagulant-containing water into the tank 20 and an inner cylinder 22 arranged inserted from the upper side of the tank 20 to the lower side of the inflow port of the outer cylinder 21 and having a lower end open in the tank 20.

System and process for the treatment of water using a ferrate-based reduction-oxidation (redox) reactor, a clarifier, and a two-stage filtration system. Three treatment substrates can be used to treat water in the water treatment system and process, namely, a ferric compound(s), an acidic oxidant, and a flocculant-adsorbent.

A mobile sewage treatment and water reclamation system and method of use thereof for rapid deployment to augment existing wastewater systems and/or provide interim service in lieu of permanent facilities, includes: (a) a denaturing stage wherein raw sewage is first ground into suspendable grit, its pH alternatively or collectively lowered to kill acid-sensitive bio-organisms, and raised to kill base-sensitive bio-organisms, and then neutralized; (b) a clarifying stage employing an inverted-cone tank to circulate the solution after injection with chemicals to flocculate small particles for collection in a layer for siphoning off; and (c) a disposal stage wherein clarified water passes through media filters to remove remaining solids and odors, the effluent water being clean enough for irrigation, aquatic life and discharge into waterways; and wherein sterile sludge is pressed into semi-dry solids, then dried, crushed, powdered and bagged for use as high-nitrate biomass fertilizer or for fossil-fuel power co-generation applications.

A calcium fluoride precipitation inhibitor is added to waste water containing sulfuric acid, fluorine (fluoride ions and hydrogen fluoride) and heavy metal ions to generate pretreated water. A calcium compound is added to the pretreated water to generate a first insolubilized product at a pH of less than 5, followed by solid-liquid separation. A calcium compound is added to a first separated water after the solid-liquid separation to generate a second insolubilized product at a pH of 3 to 7 (provided that the pH is a pH higher than in the first reaction step), followed by solid-liquid separation. An alkali is added to a second separated water after the solid-liquid separation to give a pH of 8 or more, thereby generating a third insolubilized product, followed by solid-liquid separation.

A capacitive-deionization-type nutritive salt removal system and method uses capacitive deionization (CDI) to remove nutritive salts that cause eutrophication of water due to a water-bloom phenomenon in water held by a dam or a weir. The system includes an intake pump configured to take in the water; a first nutritive salt filtration unit configured to use capacitive deionization to primarily filter out nutritive salts from the taken-in water; a second nutritive salt filtration unit configured to use capacitive deionization to secondarily filter out nutritive salts from the primarily filtered water; and a nutritive salt storage tank configured to collect and store nutritive salts filtered through the second nutritive salt filtration unit. When one filter train is operating the first or second nutritive salt filtration unit, another filter train is subjected to automatic cleaning in a standby state.

As pellets grow from seed/sand in a fluidized bed pellent reactor, the weight of the reactor is measured and the density of the contents of the reactor is calculated, and the input flow of untreated water, water treatment chemical, and seed/sand are adjusted to provide improved removal of water hardness while reducing fine particulates in the outflow of softened water from the reactor.

The invention relates to a method and an assembly for recovering magnesium ammonium phosphate from slurry that is supplied to a reaction container (10) in which an aerobic milieu is present and in which the slurry is guided in a circuit with the aid of ventilation. Cationic magnesium, such as magnesium chloride, is added to the slurry, and magnesium ammonium phosphate crystals which are precipitated from the slurry are removed via a removal device (30) provided in the base region of the reaction container. Substances which contain magnesium ammonium phosphate crystals collected in the removal device (30) are loosened and/or rinsed.

An integrated device and method for treating toxic and refractory wastewater are provided. The integrated device includes an adjusting pool, a first-stage reactor, a second-stage reactor, a third-stage reactor, a coagulation sedimentation pool, and a biochemical reaction pool that are sequentially connected in series, and further includes an aeration blower. Each of the first-stage reactor and the third-stage reactor is an advanced oxidation reactor, and the second-stage reactor is a Fenton reactor. The coagulation sedimentation pool includes 2 to 4 stages, and each stage of the coagulation sedimentation pool includes a coagulation tank, a primary sedimentation tank, and a secondary sedimentation tank that are connected in series. The biochemical reaction pool includes an anoxic tank, an aerobic tank, a settling tank, and a clean water tank that are connected in series. The wastewater treatment method combines the integrated device for treating toxic and refractory wastewater with reasonable process parameters.

A combined sedimentation tank including a flocculation tank, a transition zone and a sedimentation tank which are sequentially connected along a direction that water flows. The sedimentation tank includes a sloping plate zone and a horizontal flow zone. The length of the sloping plate zone is a quarter of the total length of the sedimentation tank. A return pipe is arranged at the bottom of the sloping plate zone. Some of sludge in the sloping plate zone is returned to the flocculation tank through the return pipe to increase the concentration of the suspended solids in the flocculation tank, thereby forming the sediments.