A method and an apparatus for maintaining a stable microbial community in a combined anaerobic-aerobic waste processing system. The system comprises cycling of waste activated sludge between reactors, thereby ensuring a healthy microbial community and an efficient waste decomposition.

A waste treatment process utilizes a two-stage digestion process with a thermophilic digester, a heat exchanger, and a mesophilic digester. The pH of the thermophilic digestate is increased by removal of carbon dioxide with an air stripper, or by adding a pH increasing reagent upstream of the heat exchanger. The pH adjustment of the digestate protects the heat exchanger and downstream equipment and processes from struvite formation. A struvite reactor may be located in various locations downstream of the heat exchanger to produce a treated digestate or effluent that contains struvite, which can optionally be recovered for beneficial use.

An anaerobic biogas plant for the digestion of fresh organic digestion substrate. The digester having an entry section with an inlet at a first end, a rear section at a second, opposite end, and a middle section arranged between the entry section and the rear section. The digester further includes a stirring unit comprising a shaft extending in the direction from the first end to the second end and having at least one agitating arm for mixing the substrate within the digester. The middle section of the digester includes a main outlet and the rear section includes an additional outlet. The digester further includes a separate return line leading from the additional outlet back to the entry section of the digester for allowing a direct return of a minor fraction of digested substrate removed from the rear section back into the entry section of the digester.

A continuous flow wastewater treatment system is disclosed. The system can include a main processing circuit comprising an anoxic entry zone and an aerobic exit zone. The system can include a granule-producing sidestream incubator. The sidestream incubator can include an inlet that receives a first portion of return activated sludge (RAS) processed by the aerobic exit zone, a sidestream anoxic zone, and a sidestream anaerobic zone that cooperate to process the first portion of RAS. The sidestream incubator can include an outlet that delivers the processed first portion of RAS to the anoxic entry zone. The sidestream incubator can include a RAS bypass pathway that bypasses the granule-producing sidestream incubator to deliver a second portion of RAS processed by the aerobic exit zone to the anoxic entry zone. In some embodiments, the RAS and/or other fermentate can be step-fed into the sidestream incubator.

A biological reactor system treats concentrated contaminated water with a combination of upflow and downflow bioreactors that are downstream from a reverse osmosis or other concentrator. The system may have a fail safe configuration where flush water may be introduced to the reactors in the event of a power failure or when taking the reactors offline. Many reverse osmosis systems introduce antiscalant treatments upstream so that the reverse osmosis filters do not scale. However, such treatments result in superconcentrated conditions of the antiscalants in the contaminated water processed by the bioreactors. A flushing system may deconcentrate the bioreactors to prevent the antiscalants from precipitating and fouling the bioreactors.

An extraction manifold for extracting digestate from a covered lagoon digester includes a digester vessel being shaped generally as a rectangular prism lacking an upward facing face and having a floor sloping generally downward from an intake face to an extraction face of the digester vessel. The intake face and extraction face are oriented vertically, situated in opposed relation on a longer horizontal axis. Each effluent pipe terminates in an extraction nozzle on one end and an independently addressable actuatable valve on the opposite end. Each actuatable valve communicates with a manifold plenum such that actuation of the valve draws digestate from the floor in a region of the floor adjacent to the extraction face and in proximity to the extraction nozzle. A valve controller actuates valves to remove digestate from the region of the floor adjacent to the extraction face. The valve controller includes sensors to monitor biogas production.

The present invention relates to a method for cleaning process water circulated in a paper recycling system, comprising a process water treatment step, which comprises at least one pre-acidification step and at least one anaerobic cleaning step, wherein at least some of the process water to be cleaned is subjected to hydrolysis and acidification in the at least one pre-acidification step and the process water thus treated is then brought into contact with anaerobic microorganisms in the at least one anaerobic cleaning step in order to break down impurities in the process water, wherein at least one saccharide-splitting enzyme is added to the process water before or during the pre-acidification step, and the pH of the process water is set to 8.0 or lower at least during the at least one pre-acidification step and during the at least one anaerobic cleaning step.

For qualitative and quantitative production of biogas, nanoparticles and use of macroalgae when added to AD feedstock at proper concentration, temperature and time of digestion can bring a revolution to meet the future needs of energy. The process of biofuel production can be altered by using various nanomaterials in various ways, such as by improving the stability of cellulose enzymes, enhancing the catalytic production of biohydrogen, and improving biological and chemical digestion. This influence of nanoparticles on the process is determined by their distinct catalytic activity based on structure, shape and size which is complementary to the relevant process. The addition of seaweed in the AD feedstock improves biogas output and digestate quality thus enhancing the economic viability with the simultaneous positive impact of reducing global warming.

In one embodiment, a system includes first anoxic moving bed biofilm reactor (MBBR) configured to receive a fluid containing selenium and to process the fluid via a first biofilm disposed on a first media to produce a first MBBR fluid by removing nitrogen from the fluid. The system further includes a second anoxic MBBR fluidly coupled to the first MBBR to receive the first MBBR fluid and to process the first MBBR fluid via a second biofilm disposed on a second media to produce a selenium enriched fluid, followed by a solid-liquid separation system to remove selenium in solid form as sludge and produce a treated effluent containing equal to or less than 5 micrograms of selenium per liter. The system includes a plurality of first sensors and first actuators disposed on the first MBBR, and a plurality of second sensors and second actuators disposed on the second MBBR.

Process for treating an aqueous fluid whereby a biogas is produced in an installation comprising a bioreactor and a separate container, the process comprising (i) a bioreactor feeding stage; (ii) a batch reaction stage, wherein biogas is formed and formed biogas is temporarily stored in the separate container, and at least one further stage (iii) comprising a settling stage and/or an aqueous fluid effluent discharge stage, wherein the biogas stored in the separate container is used to reduce fluctuations in a biogas exit flow from the installation. An installation for carrying out the process and the use thereof.