The present invention relates to a high-precision, high-efficiency recirculation system for preserving multiple-density biomass and attached biofilm in wastewater treatment bioreactors, which is characterized in that it consists of a bioreactor tank in which a central recirculation duct is centrally and vertically disposed, said duct comprising a diffuser cone at the bottom thereof, close to the bottom of a baffle of the bioreactor, and an upper guide cone at the upper end thereof, wherein the central recirculation duct is designed for an inductor/nozzle to be inserted there into up to the limit of the upper wall of the bioreactor baffle, said parts forming together a central assembly containing, in vertical attitude, a drive shaft which comprises, at the upper end thereof, above the inductor/nozzle, sealing means for hermetic sealing at the upper wall of the bioreactor baffle, wherein the upper end of the drive shaft is coupled to a low-revolution motor reducer for rotating the drive shaft, which comprises one or more axial-type impellers, and wherein the lower end of the drive shaft is coupled to a hyperbolic impeller/mixer close to the bottom of the bioreactor baffle.

Low strength wastewater such as municipal sewage is treated using an anaerobic digester. In some examples, a wastewater stream is separated into a solids rich portion and a solids lean portion. The solids lean portion is treated, for example to remove nitrogen. The solids rich portion is treated in an anaerobic digester, preferably with influent or recuperative thickening. In another example, the wastewater stream is fed to an anaerobic digester and solid-liquid separation stages downstream of the digester return active bacteria and undigested organics to the digester. Both cases may use a process train comprising treatment in an anoxic tank followed by a nitritation tank with a portion of the effluent from the nitritation tank recirculated to the anoxic tank to provide nitritation and denitritation.

Anaerobic wastewater treatment systems, devices and methods complete three-phase separation of biogas, liquids and solids (e.g., biomass) using overlapped gas hoods or baffles and one or more conically-shaped settlers having a varying cross-sectional area.

A high-concentration sewage treatment system for self-sufficiency of energy is provided. The system includes a hydrolysis acidification device, an anaerobic reactor, a sludge treatment device, a desulfurization tower, and a biogas power generation device. The hydrolysis acidification device includes a hydrolysis acidification tank, a first sedimentation tank, a first overflow water tank and an overflow pipe. The sludge treatment device includes a second sedimentation tank, a second overflow water tank, an inlet pipe and a dissolved oxygen meter. The second overflow water tank communicates with the hydrolysis acidification tank through a return pipe. The inlet pipe defines a jet hole. A regulating valve is connected to the inlet pipe. The regulating valve controls a speed and a height of mixed liquid in the jet hole. A high-concentration sewage treatment method for self-sufficiency of energy is also provided.

The invention relates to an anaerobic waste water purification tower (21) comprising a sludge reactor (22) with a waste water inlet zone (23), an active zone (24), a first set (25) of three phase separating means for separating sludge, gas and water, comprising at least one layer of adjacent gas hoods (26) connected to a gas collector tank (27) positioned above the reactor (22),and a clean water effluent outlet (31), wherein the gas hoods (26) are hooded lamellas for improving the separation of gas, sludge and water.

A mixer configured for releasing large bubbles into wastewater is provided. The mixer can include a central draft tube, an upwardly-extending member surrounding the draft tube, and an accumulator surrounding both the upwardly-extending member and the draft tube. A lower end of the draft tube sidewall may be sealed and not include any openings beneath the lower end of the upwardly-extending member, so as to prevent liquid pumpage through the draft tube. A method for treating wastewater in a system that includes at least one large bubble mixer and at least one fine bubble diffuser is also provided. The large bubble mixer and fine bubble diffuser may be supplied gas independently from one another. The method can include multiple modes of operation wherein gas is either supplied to the mixer, to the diffuser, to neither the mixer or the diffuser, or to both the mixer or the diffuser.

A syntrophic enrichment for enhanced digestion (SEED) system is presented, in which a retrofit addition to existing anaerobic digestion infrastructure provides improved digestion process rate and biogas quality. The system provides optimal niche environments for accelerating fermentative, syntrophic and methanogenic metabolisms to increase digestion system loading rates and enhance main digester microbiome. Prescribed media formulations, reactor integrations, and operational methods using various fixed and loose media enhance global digestion system performance. The retrofitted system enables existing plants to transition from an outdated solids-management model to one of valorized biomethane production.

The facility comprises: —a first tank (1) comprising separation means (15) extending over a portion of the height of the tank, so as to define a central compartment, or tube (11), a peripheral compartment, or ring (12), and a compartment for stirring and biochemical exchanges (16) in the bottom portion of the tank, comprising stirring means (17), —a second tank (2) comprising separation means (25) extending over a portion of the height of the tank, so as to define a central compartment, or tube (21), a peripheral compartment, or ring (22), and a compartment for stirring and biochemical exchanges (26) in the bottom portion of the tank, comprising stirring means (27), —means (ALIM) for feeding the waste to be treated into the first ring—means (T) for transferring the partially treated waste from the first tube to the second ring, —means (EVAC) for discharging the treated waste out of the second tube, —advantageously pneumatic means (4, 43, 44) for circulating the waste from the first ring to the second tube.

In a municipal sewage treatment system, a biological process tank, typically an anaerobic digestion process, has a flexible, inflated membrane cover. At least one draft tube mixer is installed on the tank, interrupting the gas supported cover with a platform having a flat base and may have upwardly extending sides that generally follow the contour of the inflated cover. The draft tube is connected to the platform and preferably supported on the floor of the tank. The mixer mechanism can be lifted out of the draft tube without escape of gas from the inflated cover.

The present invention belongs to the technical field of wastewater treatment, and particularly relates to a method for pre-conditioning high-calcium wastewater by calcification blocking, and a device for implementing the method. The method for treating high-calcium wastewater by calcification blocking includes mixing high-calcium wastewater, an alkalizing agent and a chelating agent, and carrying out alkalizing conditioning pretreatment under a condition of stirring by bubbling of a biogas, so as to obtain pre-conditioned wastewater. The pre-conditioned wastewater is mixed with anaerobic granular sludge, and an anaerobic reaction is performed in a high hydraulic shear flow field formed by the biogas, so as to generate the biogas and calcium scale. A part of the biogas for the stirring is refluxed by bubbling of the biogas and the rest of the biogas is refluxed for forming the high hydraulic shear flow field.