Abstract: It relates to a treatment of oil-containing waste water using a membrane biological reactor membrane biological reactor biological reactor (MBR), and it is to provide a new treatment apparatus which is capable of suppressing a reduction in biological treatment activity and suppressing an effect on a separation membrane. Provided is a membrane biological reactor having a biological reaction chamber and a membrane separation chamber, in which the it has a configuration that, within the biological reaction chamber, at least one partition is installed to have a first reaction chamber, a second reaction chamber, and if necessary, an additional reaction chamber so as to form an upflow and downflow flow path, an aeration device and a scum/oil skimmer are installed at least in the first reaction chamber, and a mixture liquid containing activated sludge is withdrawn from the membrane separation chamber and distributed and returned at least to the first reaction chamber and the second reaction chamber.

Abstract: A process for the treatment of water comprising at least the steps of: (a) providing the water in laminar flow; and (b) providing bubblefree aeration to the water. The present invention introduces aerobic treatment into wastewater settlement without any hindrance to the settlement process. The present invention is useable for any settlement step or stage, without limitation, the commonest being primary settlement or final settling.

Abstract: In one aspect, the present invention relates to novel Bacillus strains ENV 734 (NRRL B-50800), ENV 735 (NRRL B-50801), ENV 736 (NRRL B-50802), and ENV 737 (NRRL B-50803). These strains possess a high degree of homology with both Bacillus simplex and Bacillus butanolivorans, but unexpectedly exhibit desirable high salt tolerance as well as low temperature growth and urease production. In another aspect, the present invention relates to compositions comprising at least one of such strains and an acceptable carrier, and methods of preparing the compositions. Such compositions are suitable for use in industrial, agricultural, aquacultural, environmental, wastewater treatment and/or probiotic applications. Methods for enhancing the growth of a plant propagative material and methods for treating wastewater are also provided.

Abstract: A lightweight, bioplastic, mobile, floating oil spill mechanical/biological recovery system is dimensionally compact, and quick to assemble. The floating platform can be readily positioned within any waterborne oil/contaminant spill area. After assembly, this platform or apparatus can be directed by either a hand-held digital radio control transmitter or GPS directed mechanism. A lower, multi-roller slip-on belt is designed to be mounted over a circular base support aeration hub assembly with alternating/spaced slotted ring water drainage separators. The belt and aeration assemblies dip bioaugmentation product into the contaminant site thereby exposing microorganisms to both oxygen and target contaminant for treatment and metabolism. Various mechanisms for enhancing metabolic activity of the bioaugmentation product operate in tandem with the primary belt and aeration assemblies to promote effective contaminant metabolism and overall treatment regimes.

Abstract: A method and nitrification system for nitrifying a centrate stream produced from dewatering sludge within a wastewater treatment facility in which the centrate stream into a nitrification reactor containing accumulated centrate with a bacterial population of AOB and NOB nitrifying bacteria to the ammonia content within the centrate stream into nitrates and an oxygen containing gas is introduced into the accumulated centrate to support bacterial activity of the AOB and NOB nitrifying bacteria. Additionally, a conditioning method is obtained in which the bacterial population is grown within the nitrification reactor in conditioning stages that involve the introduction of incoming centrate into the reactor with a successively decreasing degree of dilution.

Abstract: Disclosed an aerobic system for decomposition of aqueous organic waste, which comprises at least a first processing container including sides, an upper opening, a substantially horizontal floor, an inlet, an outlet, at least one channel arranged at the floor having an upwardly opening mouth, a ventilating pipe extending above the mouth, and a pump connected to the pipe and arranged to provide a supply of a gas to the ventilating pipe.

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 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: In one embodiment, a method includes gasifying a fuel source using a first oxygen stream supplied from an air separation unit (ASU), discharging a gasifier blowdown from a gasification and scrubbing system configured to gasify the fuel source, generating a grey water from the gasifier blowdown, and biologically treating the grey water in a reactor using a second oxygen stream supplied by the ASU.

Abstract: A method of conditioning, separating, drying, and comminuting sulfurous acid treated wastewater suspended solids for addition to aerobic and anaerobic digesters to provide electron donor carbon and sulfur compounds to increase the removal rate of ammonia, nitrates/nitrites, and BOD compounds.

Abstract: 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.

Abstract: A system of treating high nitrogen content waste water is disclosed, where the system includes a precipitation and conditioning subsystem, an ammonia stripper subsystem, and a denitrification subsystem. The system is adapted to reduce nitrogen contamination to level below about 10 ppm and in certain embodiments below 3 ppm.

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: The present invention relates to a system or method for the remediation of wastewater with a treatment media in tandem with an electrocoagulation system. The system and method also include cleaning elements for cleaning distribution lines within the system and for cleaning the electrocoagulation system.

Abstract: This method improves and controls ex-situ or in-situ, aerobic or anaerobic digestion of organic materials and toxic or damaging compounds through increased control of multiple chemical and biological settings and conditions. The ability to control flow, natural processes, and biological activity, while adjusting to individual site conditions, offer many opportunities to modify results. Large quantities of modified or adjusted organisms are developed and utilized. Identification and strategic manipulation of the multiple elements of the system result in performance modifications. Energy is utilized to manipulate characteristics of a natural degradation system.

Abstract: Systems and methods have been developed for reclaiming water contaminated with the expected range of contaminants typically associated with produced water, including water contaminated with slick water, methanol and boron. The system includes anaerobically digesting the contaminated water, followed by aerating the water to enhance biological digestion. After aeration, the water is separated using a flotation operation that effectively removes the spent friction reducing agents and allows the treated water to be reclaimed and reused as fracturing water, even though it retains levels of contaminants, including boron and methanol, that would prevent its discharge to the environment under existing standards. The treated water may further be treated by removing the methanol via biological digestion in a bioreactor, separating a majority of the contaminants from the water by reverse osmosis and removing the boron that passes through the reverse osmosis system with a boron-removing ion exchange resin.

Abstract: A circular utilization method in pulping and papermaking processes with straw Primary pulp is obtained by digesting straw raw material according to the ammonium sulfite method. Concentrated black liquor is extruded from the primary pulp; paper pulp and diluted black liquor. The concentrated black liquor and the diluted black liquor are mixed, and a contaminated condensate is obtained. A residual concentrate or the concentrated black liquor is used for preparing a fertilizer. The contaminated condensate is mixed with one or more of the waste material obtained from stock preparation, a crop byproduct or organic waste, and substrate or fertilizer is obtained by fermenting the nitrogen source of the contaminated condensate or ammonium sulfite, or using the contaminated condensate for desulfurizing flue gas. Ammonia and flue gas are reacted to obtain the ammonium sulfite as a digestion agent; and water from recycling is used in corresponding phases of the pulping process.

Abstract: A system for mixing and mixing processes and structures are disclosed. In addition a nozzle used for mixing is disclosed.

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: Disclosed herein are an apparatus and method for cultivating microalgae using effluent from sludge treatment. The apparatus includes an advanced sewage treatment apparatus, a sludge treatment apparatus and a microalgae cultivation apparatus, the sludge treatment apparatus including: a first aerobic reactor which is operated under aerobic conditions and serves to ferment sludge; a second aerobic reactor which is operated in a state in which air is injected in an amount larger than that in the first aerobic reactor, and serves to increase the fermentation activity of microorganisms in the sludge and degrade the sludge; a membrane bio-reactor (MBR) which serves to receive effluent from the second aerobic reactor and biologically remove high-concentration organic matter from the effluent by the action of aerobic microorganisms while removing total suspended solids using a membrane, wherein the effluent discharged from the MBR reactor is supplied to the microalgae cultivation apparatus.

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 for wastewater treatment which comprises (a) separating and/or collecting urine from the wastewater for pretreatment, (b) removing phosphorus from urine using seawater, (c) optionally oxidizing nitrogen from urine, and (d) discharging the phosphorus-removed and/or nitrogen-oxidized urine to a sewer.

Abstract: Methods for enhancing an activated sludge process including at least one biological reactor. A weighting agent impregnation subsystem is coupled to the biological reactor for mixing biological flocs and weighting agent to impregnate the weighting agent into the biological flocs to form weighted biological flocs. A weighting agent recovery subsystem is configured to recover the weighting agent from the weighted biological flocs and reintroducing the recovered weighting agent to the weighting agent impregnation subsystem.

Abstract: The invention relates to a plant and a method for the treatment and disposal of waste water containing salts and oil, in particular produced water, comprising at least one settling area for receiving the waste water and for separating oil proportions from the waste water, at least one subsequent reed bed area having plants for the uptake and degradation of contaminants in the waste water, at least one modular basin area having a plurality of utility basins, whereby a utility basin, controlled by way of distribution means, can be supplied with treated waste water from the reed bed area and/or from at least one other utility basin, and at least one saline area for the reception of the residual water from the modular basin area and for the evaporation of water and the concentration of salt.

Abstract: A method and system for ballast water treatment is provided for a vessel with a ballast water tank system that pumps water from a local environment through a conduit into at least one tank on the vessel. The water contains aerobic micro-organisms from the local environment. Oxygen-containing gas is introduced into the water as it is pumped through the conduit. Living organisms are added into the water with the oxygen-containing gas introduced therein. As a result, the tank receives a mixture of the water with the oxygen-containing gas introduced therein and the living organisms added thereto. The living organisms are selected to consume (i) the aerobic micro-organisms, (ii) oxygen dissolved in the water, and (iii) food sources for the aerobic micro-organisms contained in the water. A vacuum is applied to the tank's ullage space at a point in time after the mixture is received in the tank.

Abstract: An operating method for an air diffusion apparatus is provided. The apparatus has an air diffusion unit disposed within an activated sludge aeration tank and a gas supply unit. The air diffusion unit is configured to equip one or more air diffusion pipes disposed substantially horizontally. The air diffusion pipe has a plurality of air diffusion holes on a vertical upper portion and one or more sludge passage holes on a lower portion. Gas is supplied from the gas supply unit to the air diffusion unit so that a pressure head ?H of each air diffusion pipe has a value of 0.2 to 0.9 times an inner diameter d1 of the air diffusion pipe and the gas supplying is stopped without releasing the inside of the air diffusion pipe to the atmosphere. The gas supplying step and the stopping supplying step are repeatedly operated.

Abstract: A gas dissolving apparatus that combines a gas at first pressure into a working fluid, the working present at a second pressure equal to or greater than the first pressure.

Abstract: Systems and methods for aerobically processing waste, in which an aerobic bioreactor is in selective fluid communication with a source of oxygen-rich liquid medium. The aerobic bioreactor is configured for aerobically processing waste via bacteria fixed on media to provide processed effluent from the waste. The source of oxygen-rich liquid medium is different from the aerobic bioreactor.

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 modular system for reclamation of a fluid includes a cavitation reactor operative to mechanically oxide the fluid and an ion precipitation system that receives the oxidized fluid from the cavitation reactor and thereafter introduces one or more ions at various locations to initiate precipitation of select materials. The system and associated methodology further includes injecting dissolved air and emulsion breaking chemistry into the fluid before cavitation, coalescing emulsified particulates from the fluid and saturating the fluid in an air saturation chamber that is operable to form a microbial filter.

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: A treatment system for removing a plurality of pollutants from wastewater includes a removal device for removing a plurality of gross solids from the wastewater, an aeration device for reducing a biochemical oxygen demand (BOD) and a chemical oxygen demand (COD) of the wastewater and a bioreactor containing a bacterial biofilm, said bioreactor including a plurality of cells configured for operation on a predetermined drain fill cycle.

Abstract: A system of treating high nitrogen content waste water is disclosed, where the system includes a precipitation and conditioning subsystem, an ammonia stripper subsystem, and a denitrification subsystem. The system is adapted to reduce nitrogen contamination to level below about 10 ppm and in certain embodiments below 3 ppm.

Abstract: A tanning wastewater treatment and reuse apparatus includes a coarse filter, a regulation pool, a hydraulic sieve, a desulfurization pool, a first nanocatalytic electrolyzer, a flocculation pool, a first settling pool, a flotation device, a biochemical pool, a second settling pool, a second nanocatalytic electrolyzer, a fine filter, and a compressor. Also provided is a tanning wastewater treatment and reuse method includes the steps of desulfurization, first nanocatalytic electrolysis, flocculation, biochemical treatment, second catalytic electrolysis, and filtration. The invention allows high CODCr removal rate, reduced chemical agent consumption, reduced sludge formation, thorough treatment, and high water reuse rate.

Abstract: Wastewater treatment tank for achieving hydraulic flow equalization and high efficiency soluble biological oxygen demand (BOD) removal. The wastewater treatment tank provides a compact arrangement of at least one dissolved air flotation (DAF) cell and an equalization reactor cell. The tank achieves regulatory wastewater pretreatment requirements for reducing total BOD concentrations below 250 to 300 mg/L.

Abstract: Methods for enhancing an activated sludge process including at least one biological reactor. A weighting agent impregnation subsystem is coupled to the biological reactor for mixing biological flocs and weighting agent to impregnate the weighting agent into the biological flocs to form weighted biological flocs. A weighting agent recovery subsystem is configured to recover the weighting agent from the weighted biological flocs and reintroducing the recovered weighting agent to the weighting agent impregnation subsystem.

Abstract: Biological wastewater treatment of wastewater is performed by oxidizing organic carbon with sulfur or a sulfur compound as an electron carrier, and reducing the sulfur or sulfur compound to sulfide. The sulfide is oxidized with nitrate or oxygen. If necessary, ammonia is oxidized to nitrate and then reduced to nitrogen gas. The process is effective for saline waste water facilities, as well as non-saline waste water facilities.

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.

Abstract: An atomizing spray head suitable for delivering an atomized spray of a fluid with reduced blockage within the spray head. The spray head includes an inlet having a passage therein, a female tapered seat fluidically coupled to the passage of the inlet, and a male tapered plunger seated against the female tapered seat. The male tapered plunger is adjustably biased against the female tapered seat to pressurize a fluid that flows into the passage and causes the male tapered plunger to be unseated from the female tapered seat. A window circumferentially surrounds the male tapered plunger, through which a pressurizing fluid that unseats the male tapered plunger from the female tapered seat is able to exit the spray head as an atomized spray in radial directions relative to the male tapered plunger.

Abstract: Disclosed is a system and method for treating a body of water, without the necessity of being connected to an electrical grid, that includes photovoltaic collectors and a battery bank that is charged by the photovoltaic collectors. The photovoltaic collectors and the battery bank operate a series of air pumps that are connected to an air pump manifold to create a uniform source of compressed air that is distributed to a plurality of floating diffuser manifolds. A plurality of air stones are suspended under the floating diffuser manifolds that create air bubbles that are absorbed by the body of water and circulate said body of water to disburse a microbial fluid. In addition, an incubator system is also connected to an air pump that incubates microbes to form a microbial fluid that can be automatically dispersed throughout the body of water.

Abstract: Compositions of bacteria which are effective for the nitrification of wastewater, particularly at low temperatures, are described. The compositions are comprised of 35 strains or populations of at least partially characterized isolated bacteria. These compositions may be used to treat wastewater contaminated with animal fecal waste and/or ammonia. In use, wastewater is contacted with the bacterial composition of the invention under aerobic conditions and for a period of time effective to oxidize ammonia therein.

Abstract: A method for creating Class A compost for sale to the public from waste products, especially municipal sewage, involving lower expense and improved versatility over prior methods.

Abstract: A fine bubble generating apparatus that efficiently generates fine bubbles on the nanometer level. A cylindrical member has a cylindrical inner peripheral surface, a first end wall member closing one end of the cylindrical member, and a second end wall member closing the other end of the cylindrical member. The cylindrical member and the first and second end wall members define a fluid swirling chamber. The cylindrical member has a fluid inlet hole at a position close to the second end wall member to supply a gas-liquid mixed fluid in the tangential direction of the peripheral surface of the fluid swirling chamber. The second end wall member has a fluid outlet hole extending therethrough along the center axis of the inner peripheral surface of the fluid swirling chamber. The gas-liquid mixed fluid is introduced into the fluid swirling chamber at a position close to the second end wall member.

Abstract: This invention refers to a single household waste water treatment plant, based on the SBR principle that uses two tanks, one lung tank (1) and one SBR reactor (2), allowing the significant reduction of size, and in consequence, a low consumption of power, as well as the reduction of transportation volume when several units are transferred, wherein said lung tank (1) and said SBR reactor (2) consist of one truncated cone shape external tank and one internal tank, also with truncated cone shape, wherein the internal tank has lower diameters than the external tank, wherein bases of both tanks are concentric, upon which both tanks generate two volumes, an internal volume that corresponds to the SBR reactor (2), and one external volumetric ring, that will correspond to the lung tank (1); wherein the SBR reactor has in its aeration zone duct (7) supported on legs (12), wherein such duct (7) consists of a truncated cone shaped base (13), in which upper part protrudes a cylinder (14), that will extend to the minimum

Abstract: A recirculated marine aquaculture system and process for growing crustaceans or other fish within a body of water. Water from the body of water is treated by stripping carbon dioxide and biological byproducts and by oxygenating the water. A water treatment unit may be provided to treat the water and provide movement to the body water. The water treatment unit can be configured to provide cavitation to the water, which aids in the removal of carbon dioxide and biological byproducts. Water may also be cycled through a deflocculation tank to reduce the floc of bacteria within the body of water to acceptable levels for optimal growth of crustaceans or other fish within a body of water. Using the system and the deflocculation tank has the advantage of significantly reducing the water exchange rates and even the water effluent, while maintaining acceptable water quality for growing crustaceans or other fish.

Abstract: A process and an apparatus for low-emission storage of biodegradable materials by means of aeration, without aerobic conditions materializing in the material, permits a more consistent feed of the downstream stages in the process. Aeration inhibits methanogenesis and the risk potential of an explosive gas mixture forming in the storage vessel or in the components of the system exhausting waste gas. Closed loop control of the aeration adapts the rate of aeration to the biological activity in the stored material and minimizes air input so as to minimize the loss of methanogenesis potential by aerobic conversion of the matter whilst minimizing the energy required for aeration. The process is characterized in that controlling the aeration in the storage vessel inhibits relevant methanogenesis.

Abstract: A method of biologically treating wastewater and removing contaminants from the wastewater is disclosed. In the course of treating the wastewater, biomass is produced. In addition to removing contaminants from the wastewater, the process or method of the present invention entails enhancing the PHA accumulation potential of the biomass. Disclosed are a number of processes that are employed in a biological wastewater treatment system for enhancing PHA accumulation potential. For example, enhanced PHA accumulation potential is realized by exposing the biomass to feast and famine conditions and, after exposing the biomass to famine conditions, stimulating the biomass into a period of feast by exposing the biomass to feast conditions for a selected period of time by applying an average peak stimulating RBCOD feeding rate of greater than 5 mg-COD\L\MIN in combination with an average peak specific RBCOD feeding rate greater than 0.5 mg-COD\g-VSS\MIN.

Abstract: The present invention relates to a method to induce alga and/or diatom cell bio-flocculation comprising inactivation of the expression of at least one photoreceptor in said alga and/or diatom, constructs able to inhibit the expression of at least one photoreceptor and uses thereof.

Abstract: Described herein are methods and devices for biologically treating water and/or wastewater. The methods and devices for treating waste water may be enhanced using an air-lift device which moves water and/or solids using volumes of air. This device can provide occasional surges of water using large bubbles which are able to move great volume of liquid while minimizing dissolved oxygen transfer to the surrounding liquid. Use of the devices and processes herein provides a simple, eloquent approach to waste water treatment with less operation and maintenance costs than conventional devices and/or processes.

Abstract: 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.