Abstract: A system for treating wastewater including at least one water-treatment pathway having at least one wastewater inlet, at least one oxygen-permeable, water-impermeable wall, separating an interior of the pathway from outside air, and at least one treated wastewater outlet and arranged for at least aerobic treatment of the wastewater as it flows from the at least one wastewater inlet to the at least one treated wastewater outlet, at least one wastewater supply conduit, supplying the wastewater to the at least one wastewater inlet of the water-treatment pathway and at least one treated wastewater conduit, supplying treated wastewater from the at least one treated wastewater outlet of the at least one water-treatment pathway.

Abstract: Wastewater treatment plants and processes for treating wastewater are described. The wastewater treatment plant utilizes channel plug flow dynamics with attached growth media and pure oxygen or mixtures of pure oxygen and compressed air.

Abstract: The present invention provides a method for sludge treatment, comprising the following steps: (1) mixing a sludge feed from a sewage biotreatment process with a first mixed liquor to obtain a second mixed liquor; (2) subjecting the second mixed liquor to an oxygen-supplying process to obtain a third mixed liquor; (3) subjecting the third mixed liquor to an anoxic process to obtain a fourth mixed liquor; (4) separating the fourth mixed liquor to obtain a supernatant liquid and a first concentrated mixed liquor; (5) discharging the supernatant liquid, and returning at least a part of the first concentrated mixed liquor as the first mixed liquor to the step (1), wherein the amount of sludge of the first concentrated mixed liquor that does not return to the step (1) is less than the amount of sludge of the sludge feed. The present invention further relates to the use of the method for sludge treatment in sewage treatment. The method for sludge treatment can achieve a long term stable run without sludge discharge.

Abstract: In some embodiments, a wastewater treatment system may reduce contaminants in water. A system may include one or more bioreactors which include a substrate that supports a biofilm. The bacteria used to form the biofilm may be selected to maximize the reduction of contaminants in water. Various components of the wastewater treatment system may be optimized to improve the efficiency and energy consumption of the wastewater system.

Abstract: A water treatment method and a method for producing ultrapure water are provided in which urea in raw water is sufficiently decomposed, and an organism (bacterial cells) in biological treatment is prevented from flowing downstream. In a water treatment method for performing biological treatment of raw water containing urea, a carbon source is added to the raw water, and the raw water is then supplied to biological treatment means 1 and 2 having a fixed bed formed of an organism-supporting carrier to perform the biological treatment. The biological treatment after the addition of the carbon source to the raw water improves the efficiency of decomposition and removal of urea. The biological treatment means using a fixed bed formed of an organism-supporting carrier decreases the number of bacterial cells flowing downstream.

Abstract: A wastewater treatment process that employs anaerobic granular sludge or biomass to remove chemical oxygen demand (COD) from the wastewater. Certain constituents, such as COD, nitrogen, calcium, other dissolved solids, suspended solids, can impair the effectiveness of the granular biomass. Thus, the process employs treatment units to remove these inhibiting constituents to produce a treated effluent or stream. At least a portion of the treated effluent is recycled and mixed with the influent wastewater to reduce the concentration of these inhibiting constituents.

Abstract: The microorganism-containing biocatalysts disclosed have a large population of the microorganisms irreversibly retained in the interior of the biocatalysts. The biocatalysts possess a surprisingly stable population of microorganisms and have an essential absence of debris generation from metabolic activity of the microorganisms. The biocatalysts are composed of highly hydrophilic polymer and have an internal, open, porous structure that promotes community phenotypic changes.

Abstract: A method and system of treating wastewater is disclosed. The treatment system has a nitrification-denitrification system comprising a sorption system, a biofilm system, and an anaerobic digester that digests or converts at least a portion of the solids or sludge from the sorption system and biofilm system.

Abstract: The present invention relates to microbial compositions useful in treating and remediating wastewater, removing organic matter from the surfaces of post harvested fruits and vegetables, and decreasing post-harvest disease in fruit and vegetables.

Abstract: The present invention relates to biological treatment and devices applicable in this respect. The closed container comprises a first inlet (20) and a first outlet (18), at least one vertically orientated tube (6) arranged in the container (2), the lower end of said tube being raised above the bottom of the container (2), a first gas supply (8) arranged at the lower end of said tube (6) for creating a first circulating flow (F1) of liquid and microfilm carriers through the vertically orientated tube, a second gas supply (16) arranged at the bottom and in the vicinity of the wall of the container for creating a second circulating flow (F2) of liquid and microfilm carriers. The invention additionally relates to a plurality of serially connected containers.

Abstract: A wastewater disposal method using a two-way oxygen supply horizontal-flow biofilm includes a carrier that is formed of a permeable material so that oxygen is supplied to the biofilm from the bottom layer of the biofilm adjacent to the surface of the carrier, so as to achieve a mode of simultaneously supplying oxygen from the surface layer and the bottom layer of the biofilm. Wastewater disposal equipment using a two-way oxygen supply horizontal-flow biofilm includes a water intake system, a reaction system and a water discharge system.

Abstract: A filtration device for an aquarium comprising a filtering chamber for receiving water and a filter medium therein wherein said filter medium comprises fibers having a diameter from 0.1 nm to 3000 nm and an aspect ratio of length to diameter of 5:1 to 10,000 to 1 wherein said fibers provide for colonization of nitrosomonas bacterium and/or nitrobacteria.

Abstract: The invention relates to a carrier element for an aerobic biological water treatment system. The carrier element has a first end and a second end at a distance from each other, the maximum diameter of the first end being larger than the maximum diameter of the second end. It also has biofilm growing surface structures that extend from the first end to the second end and from inner part of the element towards periphery of the element and at least two support structures that encircle the growing surface structures at the periphery of the element and connect the growing surface structures to each other. The support structures define the outer boundary surface of the carrier element, whereby the support structures are spaced from each other so that apertures allowing access to the biofilm growing surface structures are formed between the support structures. The invention relates also to a water treatment system employing the carrier elements.

Abstract: Numerous different types of waste compositions generally in an aqueous environment are bio-remediated under aerobic conditions utilizing highly diverse and multiple microorganisms within a reactor. The process is carried out with the microorganisms attached or bound by a variety of different surface characteristics to packing substrates, located within the reactor, having high surface areas and high porosity in the form of small micropores. Multiple different types of substrates are generally utilized that efficiently dissolve air into the water, as well as to maximize the concentration and diversity of types of microorganisms. Reactors are utilized that desirably have tubes therein containing the multiple types of packings and microorganisms and contain at least one perforated chimney through which air can flow and optimize dissolving oxygen into the aqueous environment of the various bio-remediation stages.

Abstract: A fluid conduit with layered and partial covering material thereon is disclosed. The fluid conduit may be used for processing and treatment of fluids which must be treated to remove materials so that the resultant treated fluid may be reused and/or returned to the earth and particularly to the water table. The fluid conduit may be of many forms and types and may have attached thereto and configured thereon covering material in partial form and a selected number of layers. The fluid conduit may be a septic pipe of smooth wall, of corrugated form, and/or of any form of cross-sectional configuration including circular, elliptical, rectangular, triangular, or any other geometric shape. The fluid conduit may be used in combination with conduit in a drainage field or leaching system usually associated with a septic tank or septic system.

Abstract: The present invention relates to a process for treating wastewater that includes the steps of: —a contact step, wherein wastewater contacts bacteria retained on a support surface and the dissolved oxygen concentration of the wastewater is maintained at 2.0 mg/l or less; an aeration step, wherein gas is passed through wastewater that has passed through the contact step and the dissolved oxygen concentration of the wastewater is reduced as the wastewater passes through the aeration step; a sedimentation step, wherein wastewater that has passed through the aeration step is substantially separated into treated water and sludge; and a sludge recycling step, wherein sludge from the sedimentation step is passed to the contact step. The invention also relates to a processing unit on which the aforementioned process may be operated.

Abstract: In some embodiments, a wastewater treatment system may reduce contaminants in water. A system may include one or more bioreactors which include a substrate that supports a biofilm. The bacteria used to form the biofilm may be selected to maximize the reduction of contaminants in water. Various components of the wastewater treatment system may be optimized to improve the efficiency and energy consumption of the wastewater system.

Abstract: A modular, vertical bioreactor system includes a plurality of vertical bioreactor chambers each of which encloses an interior volume and has a height dimension which is greater than its width dimension; a drain manifold which maintains the bioreactor chambers in a spaced apart relationship and defines a fluid channel which is in fluid communication with each of the vertical bioreactor chambers; and, a fluid delivery assembly which delivers a fluid to each of the bioreactors. The system may be reconfigured so as to accommodate varying applications. The system may be integrated with an aquaculture system.

Abstract: A system and method are provided for removal of undesirable substances from a body of liquid. The system can include an aeration structure having a continuously inclined surface configured to provide an interaction of air bubbles against substantially an entire length of the continuously inclined surface while the air bubbles are moving toward a top of the body of liquid. The continuously inclined surface can be substantially submerged in the body of liquid. A bio-film of diverse bacteria colonies is disposed on the continuously inclined surface, and a high surface area-to-volume structure is located in proximity to the aeration structure, upon which a bio-film of bacteria colonies can be formed.

Abstract: A three stage, multiple phase anaerobic digestion system and method designed to separate the biological phases, optimize microbial activity in each phase, and significantly increase system reliability and energy production. The system physically separates the biological phases of anaerobic digestion based on particle size, particle density, and solubility of metabolic products. The system allows a complex multi-phased biological system to develop without the need for excessive control or operator intervention.

Abstract: An anaerobic water purification system including an anaerobic water purification unit receiving water to be treated and providing an anaerobic-treated water output and biomass carriers for supporting anaerobic microorganisms in the anaerobic water purification unit.

Abstract: A wastewater treatment system is provided having a reactor, first and second bio media and an aeration system. The first bio medium is located proximate an inlet end of the reactor and extends vertically between a top water level and the reactor's floor. The second bio medium is located proximate an outlet end of the reactor and extends vertically between a bottom water level and the reactor's floor. The media are adapted for retaining solids within the reactor as clarified water is withdrawn after treatment. The first bio media is further adapted to act as a baffle thereby causing wastewater to flow generally uniformly into a primary reactor zone. The aeration system includes a plurality of diffusers, some of which may be located adjacent or underneath the bio media and are adapted for promoting the shaking the bio media when activated in order dislodge excessive biomass therefrom.

Abstract: A membrane supported biofilm apparatus has a plurality of hollow fiber gas permeable membranes in a tank containing water to be treated. A biofilm supported on the membranes occupies between about 40% and 80% of the volume of water to be treated in a reactor. Wastewater treatment processes are described. A process to denitrify water or treat oxidized contaminants comprises introducing hydrogen into an inner volume of the membranes to grow autotrophic organisms in the biofilm near the membrane and heterotrophic organism near the water. Another process is operated as a biomass concentration of at least 10 g/L and up to about 40 g/L to maintain a biofilm having a surface area of over 1000 square meters per cubic meter of tank volume. A hybrid process has suspended biomass and a membrane supported biofilm.

Abstract: A biological filtration system includes a reservoir configured to receive an aqueous liquid, a multiplicity of polymeric container closures in the reservoir, a fluid inlet fluidically coupled with the reservoir, and a fluid outlet fluidically coupled with the reservoir. The fluid inlet is configured such that an aqueous liquid provided to the reservoir via the fluid inlet contacts the multiplicity of polymeric container closures. The polymeric container closures support biofilm growth. Treating the aqueous liquid provided to the biological filtration system includes contacting the polymeric container closures with the aqueous liquid, growing biofilm on the polymeric container closures in contact with the aqueous liquid, thereby removing contaminants from the aqueous liquid to yield a treated aqueous liquid, and removing the treated aqueous liquid from the biological filtration system.

Abstract: Apparatus for integrated biological wastewater treatment and clarification including a tank having a wastewater inlet for receiving wastewater to be treated and having a treated, clarified wastewater outlet for providing treated, clarified wastewater for use, the tank having an upper turbulence region, a lower solids settling region below the upper turbulence region and a sludge collection region below the lower solids settling region, a multiplicity of biomass carriers disposed in the upper turbulence region, a gas diffuser assembly arranged generally between the upper turbulence region and the lower solids settling region for providing gas bubbles which move upwardly through the wastewater and the biomass carriers in the upper turbulence region, providing turbulence and oxygen and a sludge removal conduit communicating with the sludge collection region for removal of sludge therefrom.

Abstract: The present invention provides a bio-augmentation composition for improving the hydrocarbon degradation efficiency of effluent treatment plant for hydrocarbon degradation in wastewater generated from hydrocarbon processing industry and a method thereof. The composition comprises a synergistic combination of selective microorganisms to develop a consortium enabling effective degradation of hydrocarbons present in wastewater and converting thereof into harmless and environment friendly substances. The invention also provides for the said microorganisms and their isolations.

Abstract: Process for the biological treatment of organic wastes, includes a first anaerobic digestion phase and a second aerobic digestion phase in succession, a respective filtration phase of the solid substance being provided between the two digestion phases, a separation phase of the biogas released in the anaerobic digestion phase and a nitrogen recovery phase from the exhaust gases rich in ammoniac substances separated from the aerobic digestion phase. The solid substance coming from each of the filtration phases is separately returned to the respective digestion phase, while the liquid phase coming from the filtration phase downstream of the anaerobic digestion phase is sent to aerobic phase. In the nitrogen recovery phase the gaseous current consisting of exhaust gases rich in ammoniac substances is treated with a solution of carbonic acid supplied in countercurrent in a first gas/liquid contactor to obtain a mixture of nitrogen salts (ammonium bicarbonate, ammonium carbonate, etc.).

Abstract: Provided are an apparatus and a method for river water purification using a treatment soil layer and a permeable filtering medium layer. The river water purification apparatus includes a treatment soil layer and a permeable filtering medium layer which are sequentially and alternately stacked. The treatment soil layer includes a plurality of unit soil layers which are arranged at intervals. A reservoir part which stores a predetermined amount of river water and supplies the river water to an inside of the unit soil layer is provided in an upper end part of the unit soil layer. The permeable filtering medium layer has a higher hydraulic conductivity than that of the treatment soil layer. The river water purification apparatus increases a treatment flux of river water regardless of a coefficient of water permeability of soil and effectively removes nitrogen, phosphorus and nutrient salts by stably forming an anaerobic condition.

Abstract: In some embodiments, a wastewater treatment system may reduce contaminants in water. A system may include one or more bioreactors which include a substrate that supports a biofilm. The bacteria used to form the biofilm may be selected to maximize the reduction of contaminants in water. Various components of the wastewater treatment system may be optimized to improve the efficiency and energy consumption of the wastewater system.

Abstract: A method of preparing a microorganisms-immobilized felt-based resin includes the following steps: providing a mixture of an acrylate monomer, an initiator, a solvent, and water; adding a felt to the mixture; initiating a polymerization reaction of the mixture to form a felt-based resin; and immobilizing microorganisms on the felt-based resin to form the microorganisms-immobilized felt-based resin.

Abstract: An anaerobic waste treatment apparatus comprises a container wherein randomly oriented bio-film media are disposed. An example waste treatment apparatus includes a container and optionally has at least two zones of bio-film media that are disposed within the container. In one example, the bio-film media includes torus-shaped materials, or other materials with voids therein, and the container is a dug out portion of earth. Moreover, the anaerobic waste treatment apparatus may additionally comprise a waste pump that is coupled to a waste pipe and configured to introduce waste into the container at one or more locations. When two zones are included, one zone may be randomly oriented, while a proximate zone may be substantially horizontal and/or an organized zone. The random zone may also have a transition layer thereon that supports the organized zone or that provides an interface between the organized and random zones.

Abstract: An apparatus for creating floating wetlands and improving water quality is provided. The apparatus includes a lower retainer; an upper retainer; a floatable waste material disposed between the lower retainer and the upper retainer; and an organic material planted between the lower retainer and the upper retainer; wherein the organic material is configured to denitrify the water source. A method of making a floating wetland device is also provided.

Abstract: An integrated sewage biochemical treatment plant containing mechanical treatment devices, a sewage-and-sludge mixing chamber with a circulation pump and a combined biological treatment device, includes a plane feed biofilter, a spray line, collecting trays and drain collectors connected to water-jet aeratic columns sunk in the aeration zones, and aftertreatment devices. The combined biological treatment device whose capacity is 5 to 15,000 m3/day has a biofilters spray line that includes trays with emptying fittings and reflecting disks, the distance from the trays emptying fittings upper ends to the disk reflectors is 0.8 to 2 m, and the distance between the trays centers and the distance between the trays fittings axes is 0.6 to 1.8 m.

Abstract: A method of cleaning a membrane surface immersed in a liquid medium with a fluid flow, including the steps of providing a randomly generated intermittent or pulsed fluid flow along the membrane surface to dislodge fouling materials therefrom. A membrane module is also disclosed comprising a plurality of porous membranes (6) or a set of membrane modules (5) and a device (11) for providing a generally randomly generated, pulsed fluid flow such that, in use, said fluid flow moves past the surfaces of said membranes (6) to dislodge fouling materials therefrom.

Abstract: This invention relates to a refuse landfill leachate wastewater treatment system comprising a collection well, an adjustment tank, a filter, a comprehensive treatment system having a multi-stage anoxic/aerobic pool and a membrane biological reactor.

Abstract: In an apparatus for treating wastewater, e.g sewage water, the water passes through absorbent material. The material comprises e.g inexpensive scraps or off-cuts of plastic foam. The pieces of material are contained by being stuffed into lengths of plastic mesh tubing, which are then formed into closed-ended socks. The socks are stacked in layers, and the water to be treated is trickled down through the layers. The socks can also advantageously be used for anaerobic and submerged treatment of wastewater.

Abstract: A biofilm carrier screen is adapted for use with a moving bed bioreactor (MBBR). The screen has a screening body connected to an effluent pipe. The effluent pipe optionally has two parts separated by a union, preferably a pitless adapter. The screening body can be lifted from a bioreactor tank for maintenance after disconnecting the union. The screening body may have an aerator to provide bubbles to disperse biofilm carriers from the screening body. The screening bod may extend downwards from a mount near the top of the tank. In the case of an anaerobic MBBR, the screening body may extend downwards from a service box through a cover over the tank.

Abstract: This invention relates to bacteria of the genus Pseudoxanthomonas and in particular the strain deposited on Jul. 12, 2012 at the Pasteur Institute (CNCM, 25 rue du Docteur Roux, F-75724 PARIS Cedex 15, France) under No. CNCM 1-4657, capable of degrading MTBE and/or TBA. The invention also relates to a process for treatment of an effluent comprising MTBE and optionally TBA using such bacteria.

Abstract: A hollow fiber membrane module, a hollow fiber membrane module unit, and a water treatment method. The module or the module unit enable the efficient contact of microorganisms on the surface of a membrane with a gas. The module and the unit have excellent durability. The hollow fiber membrane module is formed so that the end parts of sheet-form hollow fiber membranes are formed in a substantially rectangular shape and the end face of the anchoring member on a side where the hollow fiber membranes open is formed in a substantially circular shape. The hollow fiber membrane module unit is formed in such a manner that a plurality of modules is disposed. The water treatment method is used to purify treated water with the microorganisms adhered onto the outer surfaces of the hollow fiber membranes by using the module or the unit.

Abstract: The invention relates to porous films comprising crosslinked electrospun hydrogel fibers. Viable microbes are encapsulated within the crosslinked electrospun hydrogel fibers. The crosslinked electrospun hydrogel fibers are water insoluble and permeable. The invention also relates to methods of making and using such porous films.

Abstract: In an apparatus for treating wastewater, e.g sewage water, the water passes through a standard treatment process stream to promote production of dissolved reactive phosphate ions (PO4). Iron (or aluminum) ions are generated by electrochemical means and added to the process stream at one or more locations to produce metal-P coagulant solids removed in part by pump-out, with the substantial remaining P removed by mineralization and filtration in a biological filter such as a sand filter or leach field. In another apparatus, the water passes through a standard aerobic treatment process stream to promote production of dissolved reactive phosphate ions. Iron (or aluminum) ions are generated by electrochemical means and added to the process stream at one or more locations to produce a flocculant of Fe—P minerals that are separated out by sedimentation, physical filtration or magnetic means.

Abstract: A device for the purification of organically polluted wastewater, including at least one biofilter for the wastewater purification, which biofilter includes a bioactive bed with a first layer of coconut mesocarp pieces, the device further including a water supply for supplying waste water to be purified to an upper part of the biofilter at a position above the first layer and a water collector for collecting purified water from a lower part of the biofilter at a position below the first layer. The mesocarp pieces of the first layer have a mean particle size of at least 1 cm, in that the first layer is compacted to have a density of between 75 and 275 kg/m3.

Abstract: In accordance with particular process, method and system aspects there is provided a biological manner of treating water/wastewater. Treatment is undertaken in bioreactor configured to treat the water/wastewater through a first process of denitrification followed by a second process of biological phosphorus removal. The bioreactor may be defined by multiple stages arranged in compact vertical alignment, for example, to reduce a footprint of the bioreactor and to feed the water/wastewater between the stages using gravity. The stages may comprise, in order, a Deaeration stage, an Anoxic stage, an Anaerobic stage, and an Aerobic stage. Continuous vacuum operation in the Deaeration stage enhances the physical removal of oxygen and other dissolved gases.

Abstract: A method for continuous in-situ triglyceride stabilization in FOG (Fats, Oil and Grease) commonly referred to as trap grease. The stabilization is achieved by eliminating hydrolysis and thus preventing the BTU rich triglycerides breaking down into free fatty acids (FFA) or the formation of mono- and diglycerides. A closed loop aeration and recirculation of the FOG ensures sufficient dissolved oxygen not only arresting hydrolysis but also eliminating the formation of hydrogen sulfide. The method furthermore employs the formation and continuing functioning of a biofilm for the microbiological reduction of the FOG's sulfur content. A low FFA/high triglycerides concentration as well as sulfur reduction is highly desirable, allowing for easy biodiesel fuel conversion or bio-gasification. The resulting biofuel does not exhibit the typical hygroscopic property found in B100 biodiesel.

Abstract: Wastewater systems, methods and/or kits configured such that one or more screens and one or more gases introduced into the system allow the one or more gases to at least partially contact the one or more screens to dislodge or discourage the media or solids from and/or the biology growth on the one or more screens without substantially affecting the oxygen level in the proximity of the one or more screens.

Abstract: A wastewater treatment system is provided having a reactor, first and second bio media and an aeration system. The first bio medium is located proximate an inlet end of the reactor and extends vertically between a top water level and the reactor's floor. The second bio medium is located proximate an outlet end of the reactor and extends vertically between a bottom water level and the reactor's floor. The media are adapted for retaining solids within the reactor as clarified water is withdrawn after treatment. The first bio media is further adapted to act as a baffle thereby causing wastewater to flow generally uniformly into a primary reactor zone. The aeration system includes a plurality of diffusers, some of which may be located adjacent or underneath the bio media and are adapted for promoting the shaking the bio media when activated in order dislodge excessive biomass therefrom.

Abstract: A process that utilizes ammonium oxidizing bacteria (AOB) and anaerobic ammonium oxidizing (ANAMMOX) bacteria to remove ammonium from a wastewater stream. Sludge separated from the wastewater in a mainstream is processed in a sidestream that includes an anaerobic digester, a dewatering system, and a biofilm reactor. The anaerobic digester produces digested sludge that is dewatered, producing reject water that includes a relatively high ammonium concentration and a relatively low organic carbon concentration and a relatively high temperature. The reject water is treated in a sidestream deammonification biofilm reactor that includes biofilm carriers seeded with AOB and ANAMMOX bacteria that are effective to remove ammonium from the reject water. In order to remove ammonium from the wastewater in the mainstream, the AOB and ANAMMOX bacteria on the media carriers is utilized to contact the wastewater in the mainstream and to remove ammonium therefrom.

Abstract: An apparatus, system, and process for wastewater treatment. The apparatus can include a basin for receiving a liquid to be treated, the liquid having a direction of flow, and a plurality of pendant sheets for supporting the growth of microorganisms, disposed within the basin and in contact with the liquid, wherein the pendant sheets are oriented parallel to the direction of flow of the liquid.

Abstract: The invention includes a method for the optimization of the soluble CO2 concentration in the aeration basin of an activated sludge system, which significantly improves the specific growth rate of the nitrifying bacteria. The result is a reduction in capital and energy costs for municipalities. The rate of nitrification is a product of the nitrifying bacteria biomass concentration and the specific growth rate of the bacteria. In the activated sludge system, the biomass concentration is maintained at high concentrations by reducing the wasting rate. The specific growth rate is a function of the ammonium concentration and the environmental conditions. Here, the inventors show that growth of nitrifying bacteria is inhibited when the soluble CO2 concentration is elevated beyond certain parameters. Elevated soluble CO2 concentration also reduces the pH, which also impacts the rate of growth of nitrifying bacteria.

Abstract: A ballasted sequencing batch reactor system for treating wastewater including one or more sequencing batch reactors. A weighting agent impregnation subsystem is configured to mix biological flocs and weighting agent to form weighted biological flocs. A weighting agent recovery subsystem is configured to recover weighting agent from the weighted biological flocs and reintroduce the recovered weighting agent to the weighting agent impregnation subsystem.