Provided are an apparatus and a method for biological treatment of an organic wastewater where it is possible to efficiently remove organic matter under high load while reducing the amount of air used for aerobic biological treatment and substantially decreasing the amount of sludge generated. The apparatus is provided with: a first biological treatment tank which has a fixed-type immobilized biocarrier and an aeration means; a second biological treatment tank to which a treated liquid from the first tank is introduced so as to perform treatment using suspended microorganisms, and which has an aeration means; and a sedimentation tank in which solid-liquid from the second tank is separated said liquid into settled sludge and treated water, wherein the apparatus has an influent line through which an organic wastewater is introduced to the first tank and the second tank, and a return line through which part of settled sludge discharged from the tank is returned to the tank.

Disclosed is a system for mixing gases and liquids that includes a reactor vessel and an injection assembly. The reactor vessel including a liquid inlet which receives a predetermined amount of liquid and at least one gas inlet which receives a precise amount of a gas. The reactor vessel also includes means for creating cavitation or turbulence for mixing the gas and liquid to a desired gas concentration.

A method for enhancing biochemical water treatment by a powder carrier includes: (i) screening the powder carrier by removing impurities to obtain a screened powder carrier; (ii) dissolving the screened powder carrier by stirring to prepare a slurry, enabling the screened powder carrier to completely absorb moisture to obtain a soaked powder carrier slurry; (iii) adjusting the pH value and adding the soaked powder carrier slurry into a bioreactor or a biological reaction structure; (iv) distributing the soaked powder carrier slurry uniformly through a hydraulic agitation; (v) loading a microorganism on the inner pore and wrapping on the surface of the soaked powder carrier slurry to obtain powder-loaded biological floccules; (vi) settling the powder-loaded biological floccules in a sedimentation zone and separating the powder carrier from the microorganism for reuse.

A wastewater treatment system including an aeration unit, a contact tank, a dissolved air flotation unit, and a biological treatment unit is disclosed. A method of retrofitting a wastewater treatment system by providing an aeration unit and fluidly connecting the aeration unit to the wastewater treatment system is also disclosed. A method of treating wastewater including aerating wastewater with oxygen, combining the aerated wastewater with activated sludge, floating biosolids from the activated wastewater, and biologically treating the effluent is also disclosed. The method optionally includes combining the floated biosolids with the aerated wastewater and/or activated wastewater. A method of facilitating treatment of high solids content wastewater is also disclosed.

A process for treating domestic wastewater may include directing wastewater into a tank containing a membrane filter and mixed liquor. The process may include recirculating wastewater and mixed liquor from a top end of the tank into a bottom end of the tank via a recirculation conduit. The process may include introducing a flow of wastewater and mixed liquor from the recirculation conduit into an aeration device and drawing ambient air into the aeration device using the flow of wastewater and mixed liquor from the recirculation conduit. The process may also include drawing wastewater and mixed liquor proximately surrounding the aeration device into the aeration device using the flow of wastewater and mixed liquor from the recirculation conduit. The process may include aerating a mixture of wastewater and mixed liquor with the ambient air below the membrane filter.

Provided are an anaerobic ammoxidation synergistic nitrogen removal process device of municipal sewage main and side streams and an application method thereof, comprising a municipal sewage raw water tank (1), a biological reaction pool (2), a secondary sedimentation pool (3), a sludge digestion solution raw water tank (4) and a sludge digestion solution AOB strengthening pool (5); wherein, the municipal sewage raw water tank (1) is connected with a water inlet valve (2.2) of the biological reaction pool (2) through a water inlet pump (2.1) of the biological reaction pool (2); the biological reaction pool (2) is connected with the secondary sedimentation pool (3) through a secondary sedimentation pool connection pipe (3.3); the sludge digestion solution raw water tank (4) is connected with a water outlet valve (4.1) of the sludge digestion solution raw water tank (4) through a water inlet pump (4.2) of the sludge digestion solution raw water tank (4); the sludge digestion solution AOB strengthening pool (5) is connected with an anaerobic ammoxidation region compartment of the biological reaction pool through a sludge-water mixture reflux pipe (5.8) and a sludge-water mixture reflux pump (5.11). It has the advantages of reasonability in structure design, convenience in operation, low running and maintenance cost, relatively low energy consumption, no need of an additional carbon source and the like, it can realize that short distance nitrification of municipal sewage is more stable, and it is high in low-temperature, water quantity and water quality shock resistance and can further increase volumetric load at the same time.

A system and method for aerating and mixing wastewater that includes fine bubble diffusers located at least partially below a large bubble mixer. At least a portion of the gas discharged from the fine bubble diffusers is captured by the large bubble mixer and is reused by the large bubble mixer to form and release intermittent large bubbles. Prior to being captured by the large bubble mixer, the gas discharged by the fine bubble diffusers can aerate the wastewater. The large bubble mixer includes an accumulator that, upon becoming filled with gas, generates and releases a large bubble. Upon discharge from the large bubble mixer, the large bubbles generated therein may separate into a plurality of coarse bubbles for providing additional oxygen transfer and mixing of the wastewater. The system may include supply lines for supplying gas only to the fine bubble diffuser.

The invention relates to a propeller, which is intended to be fastened to a shaft in a clamping manner, the shaft having a driver profile extending in the axial direction, wherein: the propeller is formed from multiple elements, each element (A, B, C, D) having a hub portion (1) with a counter profile (2) corresponding to the driver profile; a first connection portion (3) and a propeller blade (4) extending from the first connection portion (3) are formed on one side of the hub portion (1), and a second connection portion (5) is formed on the opposite other side of the hub portion (1); the first connection portion (3) is designed to bear interlockingly against a further second connection portion (5) of an adjacent further element (A, B, C, D); and, when the elements (A, B, C, D) are connected such that their connection portions (3, 5) bear against one another, the hub portions (1) of all the elements (A, B, C, D) complement one another to form a hub surrounding the shaft in an interlocking manner.

A method comprises flowing a mixture comprising a water-based reaction medium and at least one microalgae into a reaction vessel, wherein the reaction medium comprises a nutrient material that is consumable by a live microalgae, bacterium, or protozoa present in the reaction medium, incubating the mixture under at least intermittent illumination with a specified luminous flux such that the microalgae forms a supporting matrix that incorporates the live microalgae, bacterium, or protozoa into biologically-active bioaggregate granules, selecting out a first specified portion of the biologically-active bioaggregate granules that are smaller than a first specified size or below a first specified weight or selecting out a second specified portion of the biologically-active bioaggregate granules that are larger than a second specified size or over a second specified weight and removing the first and/or the second specified portions of the biologically-active bioaggregate granules in an effluent stream.

The invention relates to the design of an enclosure for a membrane aeration module, which incorporates a reversible, low-pressure, air-lift pump to encourage a vertical water flow through and between the membranes in the module. These enclosed membrane modules are suitable for use in membrane aerated biofilm reactors, which are used to treat water or wastewater.