Method and system for treating wastewater includes treating sludge with ozone in a plug-flow type reactor to cause lysis of biosolids in the sludge. The ozonated sludge may be provided to an anaerobic or anoxic section of the wastewater treatment system to aid the denitrification processes occurring in the anaerobic or anoxic section of the wastewater treatment system or to other sections of the wastewater treatment system such as a fermenter, an aerobic digester, or an anaerobic digester.

The methods and systems provide for the improvement in the separation of different portions of solids particles, such as bacteria, from a process stream. The methods use gas and control of fluid flow within a tank zone to provide for separation that is more selective.

A method and installation for treating wastewater containing ammonia includes feeding activated sludge from an aeration tank into a hydrocyclone. The sludge is separated into a specifically heavy fraction containing mostly anaerobic ammonia-oxidizing bacteria (anammox) and a specifically light fraction containing mostly aerobic oxidizing bacteria (AOB), which are returned to the aeration tank. The hydrocyclone includes a roughened inner wall surface for at least partially removing an organic or inorganic cover layer disposed on the anaerobic ammonium-oxidizing bacteria (anammox).

A process and system for treating wastewater is described. The invention degrades sludge produced by treatment of the wastewater to reduce or eliminate the need for sludge dewatering and disposal. The invention also reduces the amount of nutrient additives required to sustain the aerobic wastewater treatment process. In one embodiment the invention includes the steps of (a) providing an aerobic treatment system receiving a supply of the wastewater; (b) treating a supply of the sludge to rupture microbial cells present therein to produce treated sludge having an increased liquid:solid ratio and an increased degradation potential in comparison to untreated sludge; (c) conveying a supply of the treated sludge to the aerobic treatment system; and (d) substantially degrading the supply of treated sludge in the aerobic treatment system. The treated sludge may optionally be subjected to anaerobic digestion prior to delivery to the aerobic treatment system.

A process for reducing the production of sludge by municipal or industrial wastewater purification plants, comprising a step of mesophilic or thermophilic anaerobic digestion (20), or anaerobic digestion combining these two operating modes, of a stream of sludge to be treated (1), and at least one biological solubilization anaerobic treatment step (30); the process comprises, upstream of the anaerobic digestion step, a step of dehydration (10) of the sludge to be treated, followed by a step of mixing (15) the dehydrated sludge with a recirculated fraction of sludge that is more liquid, originating from recycling of the digestion (20), and/or from the anaerobic treatment step (30), and/or centrates originating from a final dehydration (50) of the treated sludge, wherein the recirculation rate is chosen such that the mixture has a dryness suitable for digestion, this mixture then being directed towards the digestion.

A method enhancing biological digestion of wastewater sludge is provided. The method uses chlorine dioxide to accelerate and improve the efficiency of aerobic or anaerobic digestion.

A wastewater treatment plant that employs an activated sludge process and a method of operating the same is described. Wastewater influent is provided to a bioreactor configured to perform activated sludge processing to develop mixed liquor suspended solids (MLSS). The MLSS is passed from the bioreactor to a hydrodynamic separator (HDS) system, where separation operations are performed on the MLSS. The separation operations generate a low concentration MLSS stream and a high concentration MLSS stream. The low concentration MLSS stream is passed from the hydrodynamic separator system via a first output to a clarifier, and the high concentration wastewater stream is passed via a second output back to the bioreactor. The clarifier performs clarification operations on the cleaned wastewater stream and then outputs an effluent flow.

A method of providing, maintaining and using a youthful added microbe population for the treatment of wastewater. A method to obtain Class A sludge without the need for disinfecting procedures.

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.

A septic system is provided that includes a septic tank having a plurality of compartments with a tank inlet in a first compartment. First and second vaults are positioned in a second compartment. The first vault receives fluid from the first compartment at a level near a fluid surface in the tank. A first flow inducer receives fluid from the first vault at a level near a bottom of the first vault, and releases fluid into the second compartment at a level near the fluid surface. The second vault receives fluid from the second compartment at a level near a bottom of the second vault and discharge fluid at a level near the fluid surface. Third and fourth vaults and a second flow inducer are positioned in a third compartment, the third vault receiving fluid from the second vault, and the fourth vault discharging fluid to a tank outlet.