# US 2021/0276908 A1 · Energy efficient decentralized wastewater reuse system incorporating multiple stages of aerobic bioreactors and recirculation for organics and nitrogen reduction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0276908 A1 - Document ID: US20210276908A1 - Status: Published application - Kind: A1 - Application number: 17/192,234 - Filed: 2021-03-04 - Published: 2021-09-09 - Earliest claimed: 2020-03-09 - Inventors: Dana K Ripley - Web page: https://patentgrep.com/patent/US20210276908A1 ## CPC - C02F 9/00: Multistage treatment of water, waste water or sewage - C02F 1/001: {Processes for the treatment of water whereby the filtration technique is of importance (C02F1/44 takes precedence; construction of filters in general B01D24/00 - B01D41/00)} - C02F 1/004: {using large scale industrial sized filters} - C02F 1/32: with ultraviolet light - C02F 1/441: {by reverse osmosis} - C02F 1/56: Macromolecular compounds - C02F 3/04: using trickle filters - C02F 3/302: {Nitrification and denitrification treatment (C02F3/308 takes precedence)} - C02F 3/305: {characterised by the denitrification} - C02F 2209/005: Processes using a programmable logic controller [PLC] - C02F 2301/046: Recirculation with an external loop - C02F 2303/04: Disinfection - Y02W 10/10: Biological treatment of water, waste water, or sewage - Y02W 10/37: using solar energy - 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 A decentralized wastewater reuse design utilizing trickling filter (TF)-based aerobic bioreactors responds to the growing need for efficient energy usage per gallon of wastewater treated and/or pound of biological oxygen demand (BOD) removed from processed influent. A facility based on this design is able to adjust power consumption as needed due to external factors, such as utility rate scheduling, grid availability, and/or renewable power sources, without compromising effluent quality performance or increasing energy intensity. The facility improves on past TF applications by overcoming physical hydraulic constraints and expanding the capacity for both aerobic nitrification and anaerobic denitrification throughout the system. This design reduces grid dependency and overall power utilization per gallon of wastewater treated and/or per pound of BOD removal in alignment with climate-oriented policies that are expected to further exert pressure on states and municipalities to shift to carbon-free energy sources supplying all of their water/wastewater facility operations. ## Claims ### Claim 1 A method of wastewater treatment, comprising: distributing a flow of influent to one or more flow equalization basins and further into an anoxic mixing basin in which anaerobic denitrification of the influent occurs; applying, in one or more primary clarifiers, one or more of: a solids collection method and a sludge collection method to the influent; collecting overflow of influent from the one or more primary clarifiers in a plurality of trickling filter pump basins comprising one or more partitions; distributing the influent in the trickling filter pump basins through one or more trickling filter towers positioned relatively above grade and comprising a media allowing a biofilm to remain thereon at a thickness that fosters BOD reduction, aerobic nitrification and anaerobic denitrification conditions; distributing influent flow from the trickling filter pump basin to one or more final clarifiers comprising a solids collection method and a sludge collection method; and filtering the influent from the final clarifier(s) through one or more continuous upflow recirculating sand filters, wherein the influent is further denitrified. ### Claim 2 (depends on 1) The method of claim 1, wherein distributing flow of the influent to one or more flow equalization basin(s) also involves distributing to the flow equalization basin(s) the flow of suspended solids recycled and sludge collected from one or more of the group consisting of: the primary clarifier(s), a sludge storage, the trickling filter pump basin(s), the final clarifier(s), and the continuous upflow recirculating sand filter(s). ### Claim 3 (depends on 1) The method of claim 1, wherein a positioning of the one or more trickling filter towers is vertically oriented higher compared to the other components in order to eliminate gravity head loss in the trickling filter towers. ### Claim 4 (depends on 1) The method of claim 1, wherein filtering the influent in one or more continuous upflow recirculating sand filters involves supplementing the influent with a coagulant polymer and/or a carbon source. ### Claim 5 (depends on 1) The method of claim 1, wherein effluent from the continuous upflow recirculating sand filters is sterilized through a redundant parallel in-line UV light system. ### Claim 6 (depends on 1) The method of claim 1, wherein effluent from the continuous upflow recirculating sand filters undergoes a reverse osmosis process. ### Claim 7 (depends on 1) The method of claim 1, comprising: accelerating influent processing in the primary clarifier(s) and the final clarifier(s) when outside of a shutdown period; and during the shutdown period, powering off all equipment except one or more of the group consisting of: a flow equalization basin mixer, an anoxic mixing basin mixer, one or more pumps of the trickling filter pump basins, and a trickling filter ventilation blower. ### Claim 8 (depends on 7) The method of claim 7, wherein during the shutdown period, the method comprises: recirculating influent from a final trickling filter tower of the one or more trickling filter towers to the flow equalization basin(s).