Provided is a solid precipitation reactor useful for waste-water treatment. The reactor can include a reaction chamber configured to receive feedwater and to allow particulates to at least partially precipitate from the feedwater to form an effluent, and a membrane module having at least one membrane filter configured to receive effluent from the reaction chamber and to filter suspended particulates from the effluent to produce a permeate and a concentrate. The concentrate can be reintroduced to the re-action chamber to allow additional particulates to precipitate. Systems and methods for wastewater treatment, and methods for regenerating a zeolite cation exchanger, using the solid precipitation reactor are also provided.

Method for treating a fluid aqueous waste stream comprising a biodegradable organic substance, comprisingfeeding said stream into a bioreactor containing a fluid which contains biomass;reacting the biodegradable organic substance with the biomass in the bioreactor under essentially anaerobic conditions;taking a first flow from the bioreactor and using the first flow as a feed to a membrane filtration unit, in which said feed is subjected to filtration, thereby forming a permeate stream and a retentate stream;returning the retentate stream to the bioreactor;taking a second flow from the bioreactor as feed to a sludge treatment unit, in which sludge treatment unit the second flow is separated into a third flow, having an increased organic substance content compared to the second flow, and a fourth flow, having a decreased organic substance content compared to the second flow.

The present invention provides methods and compositions for improving permeability and flux in a membrane filtration system, especially in water or wastewater treatment processes.

In a membrane filtration system and process, retentate exiting a filtration element is maintained inside a loop and redirected back to the inlet of a pump. The pump may produce a generally constant velocity in the loop. Water is concentrated inside the loop until discharged in batches. Feed water enters the loop automatically. The flux through the filtration element is maintained by a controlled valve or pump in communication with a permeate outlet. A filtration element has one or more rigid inserts in a housing. The inserts are covered with membranes. The element is configured to provide open feed channels beside the inserts. The membranes and inserts are potted at an edge, which may be their only attachment to the housing. Permeate flows between the membrane and the insert to the potted edge. The filtration element may be used in the system and process described herein or in others.

In one embodiment, a portable wastewater treatment system includes an anaerobic reactor in which organic material within the wastewater can be broken down, a membrane filter that receives wastewater from the anaerobic reactor and filters the water to produce permeate, and a small shipping container in which the reactor and the membrane filter are contained.

A screw press has a cylindrical screening section mounted to a frame. The screening section is able to rotate but can be prevented from rotating. A sprayer system is operable to spray water on the screening section. In a cleaning process, the screening section is rotated while water is sprayed against it. Optionally, the power required to rotate the screen may be provided by an auger drive mechanism. The screening section may have openings sized to retain flocculated solids. The screw press may be used to thicken a sludge from a waste water treatment plant.

Feed water is processed in an anaerobic digester. A solid-liquid separation device, for example a sludge screw thickener, treats a stream drawn from the digester in a recirculation loop. The solids portion is returned to the digester to increase the solids retention time and the TSS concentration in the digester. A liquid portion with less than 5% of the solids in the stream is removed and optionally treated further. The flow rate to the solid-liquid separation device is preferably greater than the influent flow rate. The solid-liquid separation device may receive digestate at a TSS concentration of 4% or more and return a solids portion having a TSS concentration of over 10%. The feed water is preferably one or more industrial waste streams having a COD concentration of 20,000 to 50,000 mg/L and a TSS concentration from 1-5%. The organic loading rate may be 10-12 kg/COD/m3/day.

The disclosure relates to bioreactors, for example for biological treatment and, more specifically to bioreactor insert apparatus including biofilms and related methods. The bioreactor insert apparatus provides a means for circulation of reaction medium within the bioreactor, a biofilm support, and biological treatment of an inlet feed to the reactor/insert apparatus. The bioreactor insert apparatus has a high relative surface area for biofilm attachment and is capable of generating complex flow patterns and increasing treatment efficiency/biological conversion activity in a biologically-active reactor. The high surface area structure incorporates multiple biofilm support structures such as meshes at inlet and outlet portions of the structure. The biofilm support structures and biofilms thereon can increase overall reaction rate of the bioreactor and/or perform some solid/liquid separation in the treatment of the wastewater or other influent.

Methods and systems for recovering nutrient-enriched products from wastewater are provided. Liquid permeate streams recovered from a membrane-type bioreactor may be further treated to remove carbonate species, and then contacted with at least one calcium-containing coagulant. The resulting solids-containing product may be enriched in one or more nutrients, such as phosphorous, and can be used in subsequent applications. such as fertilizers. The resulting liquid stream may also be treated to provide a treated water stream. Methods and systems described herein provide energy-efficient, sustainable processes for treating wastewater and recovering valuable products therefrom.

Methods of controlling hydrogen sulfide concentration of a biogas occupying an anaerobic membrane bioreactor (AnMBR) containing a submerged membrane are disclosed herein. Methods of controlling dissolved sulfide concentration of a mixed liquor within the AnMBR are disclosed. The methods include directing wastewater containing sulfur and a chemical oxygen demand (COD) to an AnMBR, withdrawing at least a fraction of the biogas from the AnMBR, directing a pre-determined amount of the withdrawn biogas to a scrubber, directing a remainder of the withdrawn biogas to a gas distributor, and directing the scrubbed biogas to the AnMBR. Systems for treating wastewater having sulfur and COD are disclosed. The systems include an AnMBR, a scouring gas closed loop, a scrubber, and a control mechanism for directing biogas to the scrubber and to a gas distributor. Methods of retrofitting a system for treating wastewater having sulfur and COD are disclosed.