# US 11,078,098 B2 · Flow equalization reactor having multiple wastewater treatment zones > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,078,098 B2 - Document ID: US11078098B2 - Status: Granted - Kind: B2 - Application number: 16/203,277 - Filed: 2018-11-28 - Published: 2019-03-28 - Granted: 2021-08-03 - Earliest claimed: 2016-07-06 - Applicants: John H. Reid - Inventors: John H. Reid - Web page: https://patentgrep.com/patent/US11078098B2 ## CPC - C02F 3/302: {Nitrification and denitrification treatment (C02F3/308 takes precedence)} - C02F 3/006: {Regulation methods for biological treatment} - C02F 3/301: {Aerobic and anaerobic treatment in the same reactor} - C02F 3/307: {characterised by direct conversion of nitrite to molecular nitrogen, e.g. by using the Anammox process} - C02F 3/308: {Biological phosphorus removal} - C02F 2101/105: {Phosphorus compounds} - C02F 2101/16: Nitrogen compounds, e.g. ammonia - C02F 2209/40: Liquid flow rate - 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 A method of treating wastewater is disclosed in which a flow equalization reactor is provided that includes at least one wastewater treatment zone. A first wastewater treatment process is performed in the at least one wastewater treatment zone, which can be switched to a second wastewater treatment process. The flow equalization reactor is designed with a variable liquid depth and volume that can operated as a mixed wastewater zone, an anaerobic reactor zone, an anoxic reactor zone or an aerobic reactor zone. The equalization reactor provides sufficient variable liquid depth and volume above a minimum liquid depth and residual volume to provide the necessary hydraulic flow equalization or surge volume to achieve a relatively constant effluent pumping rate or feed forward flow rate over 24 hours per day, seven days per week into the downstream biological treatment processes, clarifiers, filters, or disinfection units, etc. ## Claims ### Claim 1 A method of treating wastewater in a dual train or multi-train biological wastewater treatment system comprising: providing at least two flow equalization reactors upstream of a dual train or multi-train wastewater treatment system comprising more than one wastewater treatment zone; and, operating the at least two flow equalization reactors in series, wherein the at least two flow equalization reactors comprise at least one biological reactor. ### Claim 2 (depends on 1) The method according to claim 1, wherein the biological wastewater treatment is selected from the group consisting of carbonaceous biological oxygen demand (BOD) removal, luxury biological phosphorous uptake, nitrite removal, nitrate removal, nitrite and nitrate removal, and ammonium nitrogen removal. ### Claim 3 (depends on 1) The method according to claim 1, further comprising an inflow Q of wastewater flowing into the at least two flow equalization reactors, wherein the inflow Q of wastewater is screened raw wastewater, screened stormwater, a mixture of screened raw wastewater and screened stormwater, a primary clarifier effluent, a dissolved air flotation (DAF) pretreatment system effluent, an anaerobic lagoon effluent, or an anaerobic reactor effluent. ### Claim 4 (depends on 1) The method according to claim 1, wherein an outflow from the more than one wastewater treatment zone has a substantially constant pumping rate or feed forward flow rate. ### Claim 5 (depends on 1) The method according to claim 1, wherein a downstream wastewater treatment stage is selected from one or more of a downstream nitrification stage, a downstream nitritation stage, an anammox reactor stage, and a final clarifier stage. ### Claim 6 (depends on 5) The method according to claim 5, further comprising: providing a nitrate and/or nitrite mixed liquor recycle flow (NITR) line from the downstream wastewater treatment stage to an upstream wastewater treatment stage. ### Claim 7 (depends on 6) The method according to claim 6, wherein a nitrite and/or nitrate mixed liquor recycle flow through the (NITR) line is of from 100% to 400% of the inflow Q into the flow equalization reactor. ### Claim 8 (depends on 1) The method according to claim 1, further comprising: providing a return activated sludge line from a downstream wastewater treatment stage to an upstream wastewater treatment stage. ### Claim 9 (depends on 1) The method according to claim 1, further comprising: providing an anoxic mixed liquor recycle flow of from 50% to 200% of an inflow Q from a downstream wastewater treatment zone to an upstream wastewater treatment zone. ### Claim 10 (depends on 1) The method of claim 1, wherein all trains of the dual train or multi-train wastewater treatment system provide flow equalization. ### Claim 11 A method of treating wastewater in a dual train or multi-train biological wastewater treatment system comprising: providing at least two flow equalization reactors upstream of a dual train or multi-train wastewater treatment system comprising more than one wastewater treatment zone; operating the at least two flow equalization reactors in series; operating a first flow equalization zone or reactor as a first stage anaerobic reactor for biological phosphorous removal; conducting an outflow from the first flow equalization zone or reactor to a second flow equalization zone or reactor; operating the second flow equalization zone or reactor as an anoxic denitrification zone or reactor for biological nitrogen removal; and, operating a third flow equalization zone or reactor as an aerobic nitrification reactor for biological ammonia nitrogen removal, wherein the at least two flow equalization reactors comprise at least one biological reactor. ### Claim 12 (depends on 11) The method of claim 11, further comprising operating a fourth flow equalization zone or reactor and/or a fifth flow equalization zone or reactor for further aerobic treatment. ### Claim 13 (depends on 12) The method of claim 12, wherein wastewater discharge from the fourth or fifth flow equalization zone is discharged into a flow splitter that is conducted to one or more clarifiers. ### Claim 14 (depends on 13) The method of claim 13, wherein a return activated sludge line recycles activated sludge from the one or more clarifiers to the anoxic denitrification treatment zone. ### Claim 15 (depends on 11) The method of claim 11, wherein the third flow equalization zone is operated as a constant volume nitrification reactor. ### Claim 16 A method of treating wastewater in a dual train or multi-train biological wastewater treatment system comprising: providing at least two flow equalization reactors upstream of a dual train or multi-train wastewater treatment system comprising more than one wastewater treatment zone; operating the at least two flow equalization reactors in series; and providing a return activated sludge line from a downstream wastewater treatment stage to an upstream wastewater treatment stage, wherein the at least two flow equalization reactors comprise at least one biological reactor, and wherein a return activated sludge flow through the return activated sludge line is of from 50% to 200% of the inflow of wastewater into the flow equalization reactor. ### Claim 17 A method of treating wastewater in a dual train or multi-train biological wastewater treatment system comprising: providing at least two flow equalization reactors upstream of a dual train or multi-train wastewater treatment system comprising more than one wastewater treatment zone; operating the at least two flow equalization reactors in series; operating a first flow equalization zone or reactor as a first stage anaerobic reactor for biological phosphorous removal; conducting an outflow from the first flow equalization zone or reactor to a second flow equalization zone or reactor; operating the second flow equalization zone or reactor as an anoxic denitrification reactor for biological nitrogen removal; operating a third flow equalization zone or reactor as an aerobic nitrification reactor for biological ammonia nitrogen removal; providing a nitrite mixed liquor recycle flow from a nitritation reactor into a first wastewater treatment zone of one of the flow equalization reactors; obtaining a total outflow out of the flow equalization reactor, the total outflow having a volume corresponding to a total volume of an inflow Q and the nitrite mixed liquor recycle flow; conducting about 55% of a total inflow from the flow equalization reactor into a nitritation reactor as a flow Q1; receiving about 45% of a total inflow from the flow equalization reactor as a flow Q2; and, mixing the flow Q1 and the flow Q2, wherein the at least two flow equalization reactors comprise at least one biological reactor. ### Claim 18 (depends on 17) The method according to claim 17, further comprising: receiving the mixture of the flow Q1 and the flow Q2 in an anammox reactor. ### Claim 19 (depends on 18) The method according to claim 18, further comprising: receiving an outflow from the anammox reactor in a final clarifier. ### Claim 20 (depends on 19) The method according to claim 19, further comprising: providing a first return activated sludge flow from the final clarifier in the nitritation reactor; and, providing a second return activated sludge flow from the final clarifier to the anammox reactor. ### Claim 21 (depends on 20) The method according to claim 20, wherein the first activated sludge flow is of from 0% to 20% of an inflow of wastewater into the flow equalization reactor, and wherein the second activated sludge flow is of from 80% to 200% of the inflow of wastewater into the flow equalization reactor. ### Claim 22 A method of treating wastewater in a dual train or multi-train biological wastewater treatment system comprising: providing at least two flow equalization reactors upstream of a dual train or multi-train wastewater treatment system comprising more than one wastewater treatment zone; operating the at least two flow equalization reactors in series; operating at least one of the at least two flow equalization reactors as a first stage anaerobic reactor for biological phosphorous removal; and operating at least one of the at least two flow equalization reactors as an anoxic denitrification reactor for biological nitrogen removal; wherein the at least two flow equalization reactors comprise at least one biological reactor.