# US 2021/0276903 A1 · Membrane aerated secondary clarifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0276903 A1 - Document ID: US20210276903A1 - Status: Published application - Kind: A1 - Application number: 16/336,690 - Filed: 2017-09-25 - Published: 2021-09-09 - Earliest claimed: 2016-09-26 - Assignees: Fluence Water Products and Innovation Ltd - Applicants: Fluence Water Products and Innovation Ltd - Inventors: Ronen-Itzhak SHECHTER; Noam Mordechai SIEGEL - Web page: https://patentgrep.com/patent/US20210276903A1 ## CPC - C02F 3/208: {Membrane aeration (C02F3/201 takes precedence)} - C02F 1/727: {using pure oxygen or oxygen rich gas} - C02F 3/102: {Permeable membranes} - C02F 3/201: {Perforated, resilient plastic diffusers, e.g. membranes, sheets, foils, tubes, hoses} - C02F 3/205: {Moving, e.g. rotary, diffusers; Stationary diffusers with moving, e.g. rotary, distributors} - C02F 2001/007: {Processes including a sedimentation step} - Y02W 10/10: Biological treatment of water, waste water, or sewage - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT ## Abstract Provided is a clarifier unit of wastewater treatment system and a system comprising the unit, the unit including a treatment tank having a bottom wall, side walls, influent inlet, clarified water outlet and a sludge discharge outlet; wherein the unit has an oxygen supply assembly, including one or more oxygen supply elements confined to a bottom portion of the tank, each of which includes (i) a water-tight enclosure including oxygen-permeable membranes permitting oxygen permeation by, for example, a diffusion from the enclosure to a surrounding medium, and (ii) a gas inlet for receiving an oxygen-containing gas and a gas outlet for removal of gas. ## Claims ### Claim at position 1 -24. (canceled) ### Claim 25 A clarifier unit of wastewater treatment system, comprising: a treatment tank having a bottom wall, side walls, influent inlet, clarified water outlet and a sludge discharge outlet; wherein the unit has an oxygen supply assembly, comprising one or more oxygen supply elements confined to a bottom portion of the tank, each of which comprises: a water-tight enclosure comprising oxygen-permeable membranes permitting oxygen permeation from the enclosure to a surrounding medium, and a gas inlet for receiving an oxygen-containing gas and a gas outlet for removal of gas. ### Claim 26 (depends on 25) The unit of claim 25, comprising one or both of a scraper adjacent the bottom wall for scraping sludge off the bottom wall and a conveyor for feeding the sludge sediment to the sludge outlet. ### Claim 27 (depends on 26) The unit of claim 26, wherein the one or more oxygen supply elements are situated above a scraper or conveyor situated at the bottom of the tank. ### Claim 28 (depends on 25) The unit of claim 25, wherein the at least one oxygen supply element is positioned such that it is entirely below the clarified water outlet. ### Claim 29 (depends on 25) The unit of claim 25, being a secondary clarifier. ### Claim 30 (depends on 25) The unit of claim 25, wherein the enclosure is defined between two oxygen-permeable membranes. ### Claim 31 (depends on 30) The unit of claim 30, wherein the two oxygen-permeable membranes are essentially parallel to one another. ### Claim 32 (depends on 30) The unit of claim 30, wherein the enclosure comprises one or more spacer elements between the two oxygen-permeable membranes. ### Claim 33 (depends on 30) The unit of claim 30, wherein the oxygen-permeable membranes are essentially vertically oriented. ### Claim 34 (depends on 33) The unit of claim 33, wherein the one or more oxygen supply elements are generally planar elements. ### Claim 35 (depends on 33) The unit of claim 33, wherein the one or more oxygen supply elements are configured as elongated sleeves. ### Claim 36 (depends on 32) The unit of claim 32, wherein the one or more oxygen supply elements define a generally circular path. ### Claim 37 (depends on 36) The unit of claim 36, comprising a plurality of concentric oxygen supply elements. ### Claim 38 (depends on 36) The unit of claim 36, comprising one or more spirally-arranged oxygen supply elements. ### Claim 39 (depends on 25) The unit of claim 25, wherein the oxygen permeable membranes comprise on their external, aqueous-facing face at least one of alkyl-acrylate or poly-methyl-pentene. ### Claim 40 (depends on 25) The unit of claim 25, comprising a plurality of oxygen supply elements configured as plates. ### Claim 41 (depends on 40) The unit of claim 40, wherein the oxygen supply element plates are arranged in an array, in which one or more oxygen supply element plates is oriented parallel to one or more other supply element plates. ### Claim 42 (depends on 40) The unit of claim 40, wherein the oxygen supply element plates have a radial orientation, optionally the oxygen supply element plates are fixed on one or more revolvable radial arms. ### Claim 43 (depends on 40) The unit of claim 40, wherein the one or more oxygen supply element plates are integral with a scraper adjacent the bottom wall for scraping sludge off the bottom wall and a conveyor for feeding the sludge sediment to the sludge outlet. ### Claim 44 (depends on 25) A water treatment system comprising a water treatment unit of claim 25.