Ovivo Luxembourg S.a.r.l.

Ovivo Inc.

Enviroquip Inc.

Aquaconsult Anlagenbau Gmbh

Glv Finance Hungary Kft

Eimco Water Technologies LLC

Dennis Livingston

James Porteous

Elena Bailey

Hiren Trivedi

Peter J Bugg

Roland Schneider

Noboru Funakubo

Mike Ollivant

Steve Stach

Edward Alan David

Mark Steelman Stone

Christopher Bryan Lewis

Douglas John Boucher

Clyde Wayne Holliman

Rick Whisenant

Clay Brandon Rich

Douglas John Bucher

James A Telfer

A wastewater treatment system includes a biological treatment plant and an auxiliary, non-biological treatment plant. The auxiliary plant receives overflow, which can be sanitary sewer overflow, combined sewer overflow or strictly storm overflow. Treatment is by coagulation and membrane separation, removing most bacteria. Following treatment the outflow can be discharged to streams.

Membrane wastewater treatment of combined sewer overflows and sanitary sewer overflows

A submerged membrane unit has air diffusers located outside of the membrane area in plan view. The diffusers may be mounted in or below a diffuser case. The diffuser case may have walls to direct bubbles towards the membranes. The diffusers may be drop diffusers, for example as in a single drop diffuser assembly. The membrane unit may have polymeric or ceramic membranes, for example ceramic flat plate membranes. In an example, a rectangular shrouded membrane unit has a diffuser case below it that is rectangular in plan view but trapezoidal in side view, with drop diffusers located in the corners of the diffuser case. In a process of treating high strength wastewater, for example thickening or digesting waste sludge, a membrane unit optionally with ceramic plate membranes is immersed in the wastewater. The membranes are sparged with bubbles produced below but beside the membrane unit in a diffuser case.

Submerged membrane unit diffuser case

In a submerged membrane bioreactor (MBR or SMU), diffusers are used to eject air bubbles, primarily to facilitate the movement of mixed liquor past the membrane surfaces, cleaning and scouring the surfaces of the membranes with the mechanical energy of the combined air/liquid/solids movement. Oxygen transfer from the bubbles into the mixed liquor is often a secondary goal, for supplying oxygen to biological processes. The invention involves the use of a specific bubble diffuser, oriented at a selected upward angle, to enable a single style diffuser to accomplish simultaneous generation of mid-size and fine bubble aeration, with adjustment of the tilt angle varying the percentages of mid-size and fine bubble aeration. The angle selection, along with the number of diffusers and air volume selected, allows achievement of target liquid movement through the MBR.

Adjustable variable bubble size aeration for submerged membrane air scour

In a sewage treatment plant with a membrane bioreactor (MBR), raw untreated or partially treated wastewater (influent) and/or mixed liquor in the intensified process is superoxygenated. In a preferred form of the process the influent is superoxygenated such that membrane air scouring requirements are reduced. Influent may be fed to a swing zone where denitrification and nitrification occur simultaneously through process control. In one embodiment superoxygenation is conducted in an internal recycle stream of the mixed liquor, with oxygen content supersaturated preferably to over 300 parts per million. Due to the active evolution of oxygen gas from the supersaturated stream, occurring preferably by seeding the supersaturated stream with air bubbles, the supersaturated oxygen can serve the dual purposes of meeting process oxygen demands and providing part of air scouring requirements for the membranes.

Membrane bioreactor with reduced air scour requirements

A biological wastewater treatment system includes an equalization tank for sending a defined first portion of the wastewater to a submerged membrane filter. When the quantity of the received wastewater exceeds the defined first portion, a second portion of wastewater, formed from the wastewater that exceeds the defined first portion, is sent to a filtration process. The filtration process includes adding a flocculating agent to the second portion entering filtration, filtering the second portion, thereby producing retentive waste including flocculated material, and then sending the retentive waste to the submerged membrane filter.

Peak flow management in wastewater treatment using direct membrane filtration

Flat-sheet membrane filter assemblies require open space around equipment to form a viable path for an internal recycle or roll pattern. Creating a dedicated roll pattern for individual filter assemblies is space intensive and imposes process constraints on tank dimensions. A hollow wall or series of pipes forms a recycle wall designed to consolidate roll patterns and reduces space requirements. The recycle wall is designed such that the structural components also serve as a mixed liquor distribution system for the necessary roll pattern. Fixed vertically oriented conduit and sectional channel pieces allow for easy access and removal of membrane filter assemblies installed side by side. Feeding mixed liquor, air and or influent to the bottom of filter assemblies via submerged conduit improves process efficiency when coupled with return channels spaced not more than 10 feet away and above assemblies. The system is particularly advantageous for flat-sheet membrane filter units used in SMBR applications but is adaptable to other technologies including tubular and hollow-fiber membrane filter assemblies.

Efficient arrangement of membrane bioreactors

In a sewage treatment system, microconstituents, including personal care products and pharmaceutical materials, often difficult to degrade biologically, are removed by supersaturating the untreated wastewater feed with ozone. This breaks down refractory microconstituents into more readily biodegradable materials, subsequently treated preferably in an activated sludge membrane bioreactor process. The oxygen byproduct of ozonation is utilized by feeding the oxygen into an aerobic part of the plant to meet a portion of the biological demand, thereby increasing efficiency of ozone use in the process.

Wastewater treatment method and system with ozonation for microconstituent removal

Method using membrane bioreactor with reduced air scour requirements

A cleaning system and method remove localized caked or dewatered solids from flat-plate membranes in a sewage treatment plant. The caked sludge on the membranes is removed by intense coherent water sprays directed into the spaces between cartridges of a cassette, without removing the cartridges from the cassette. The sprays can be delivered from the top and/or bottom of the cassette, or the side panels of a cassette can be removed for spraying from at least one side, preferably both sides, using a mechanical device with movable spray bars and motor-driven advancing of the spray bars. In one preferred form of the system the apparatus includes horizontal cutting jets followed by angled cutting jets that further break up and wash away the loosened sludge. Jet diameter, velocity and pressure are controlled so as not to damage the membranes or cartridges but to achieve efficient cleaning.

Cleaning system for flat-plate membrane cartridges

A sewage treatment plant, on the liquid side, is operated so as to effect nitrification and denitrification within a single tank and simultaneously to remove water, without the need for separate clarification. An aerobic/anoxic zone is maintained in a single tank, wherein the SymBio process of U.S. Pat. No. 5,906,746 is maintained. This is combined with the advantages of an MBR process, by placing a series of membrane separators within the tank and continuously withdrawing nearly pure water. Supplemental process air provided in the MBR tank is controlled by the SymBio process to maintain simultaneous nitrification and denitrification in a single tank and thus reducing the additional process air requirements.

Growing community of inventors

Austin, TX, United States of America

Dennis Livingston