# US 2017/0283291 A1 · Nitrogen-reducing wastewater treatment system

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2017/0283291 A1
- Document ID: US20170283291A1
- Status: Published application
- Kind: A1
- Application number: 15/629,206
- Filed: 2017-06-21
- Published: 2017-10-05
- Earliest claimed: 2012-12-19
- Assignees: A.K. Industries, Inc.
- Applicants: A.K. Industries, Inc.
- Inventors: Stephen Sabo; Steven Davis; James Conley
- Web page: https://patentgrep.com/patent/US20170283291A1

## CPC

- C02F 3/302: {Nitrification and denitrification treatment (C02F3/308 takes precedence)}
- C02F 3/1242: {Small compact installations for use in homes, apartment blocks, hotels or the like}
- C02F 2209/10: Solids, e.g. total solids [TS], total suspended solids [TSS] or volatile solids [VS]
- 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 wastewater treatment system is provided having a pretreatment tank which receives wastewater from a wastewater source, and an aeration tank which is in fluid communication with the pretreatment tank. A recirculation pump is carried in the aeration tank and returns wastewater from the aeration tank to the pretreatment tank. The recirculation pump returns the wastewater according to a recirculation ratio R:I where R is the volumetric flow rate of wastewater through the recirculation pump and I is average volumetric flow rate of wastewater entering the pretreatment tank. A control panel cycles the recirculation pump on and off according to the recirculation ratio.

## Claims

### Claim 1

A method of treating wastewater:
providing a pretreatment tank having an inlet and an outlet, said inlet receiving wastewater influent from a wastewater source;
providing an aeration tank having an inlet and an outlet, said inlet of said aeration tank in fluid communication with said outlet of said pretreatment tank and receiving said wastewater from said pretreatment tank;
aerating a portion of said aeration tank to provide aerobic conditions that induce nitrification;
providing a sensor to measure suspended solids in said aeration tank;
providing a recirculating pump to pump a portion of said wastewater in said aeration tank to said pretreatment tank in pulses;
maintaining suspended solids in said aeration tank at a predetermined level by pulsing said recirculating pump when said suspended solids in said aeration tank exceed said predetermined level;
discharging said recirculated wastewater from outlets adjacent a floor in said pretreatment tank, said outlets being pointed in opposite directions to impart rotational stirring of said wastewater in said pretreatment tank;
maintaining anoxic conditions in said pretreatment tank to preferentially select for facultative bacteria to populate both said aeration tank and said pretreatment tank.

### Claim 2 (depends on 1)

The method of claim 1, wherein said inlet of said pretreatment tank includes a flow meter for measuring said wastewater received in said inlet of said pretreatment tank.

### Claim 3 (depends on 1)

The method of claim 1, wherein said control panel receives a signal from said sensor in said aeration tank and pulses said recirculation pump when said sensor sends a signal that said suspended solids in said aeration tank exceed a predetermined level.

### Claim 4 (depends on 1)

The method of claim 1, wherein said sensor is an optical sensor that detects the opacity of said wastewater in said aeration tank.

### Claim 5 (depends on 4)

The method of claim 4, wherein said control panel receives a signal from said sensor in said aeration tank and pulses said recirculation pump when said sensor sends a signal that said suspended solids in said aeration tank exceed a predetermined level.

### Claim 6

A wastewater treatment system comprising:
a pretreatment tank having an inlet and an outlet, said pretreatment tank having an anoxic condition, said inlet of said pretreatment tank adapted for receiving wastewater influent from a wastewater source;
an aeration tank having an inlet and an outlet, said inlet of said aeration tank in fluid communication with said outlet of said pretreatment tank and adapted for receiving said wastewater from said pretreatment tank, a portion of said aeration tank having aerobic conditions that induces nitrification;
a sensor adapted to measure suspended solids in said aeration tank;
a recirculating pump to pump a portion of said wastewater in said aeration tank to said pretreatment tank in pulses;
a control panel for receiving signals from said sensor, said control panel adapted to pulse said recirculating pump when said suspended solids in said aeration tank exceed a predetermined level;
outlets adjacent a floor in said pretreatment tank in fluid communication with said recirculation pump, said outlets being pointed in opposite directions to impart rotational stirring of said wastewater in said pretreatment tank when fluid is discharged from said outlets.

### Claim 7 (depends on 6)

The wastewater treatment system of claim 6, wherein said control panel pulses said recirculation pump when said sensor sends a signal that said suspended solids in said aeration tank exceed a predetermined level.

### Claim 8 (depends on 7)

The wastewater treatment system of claim 7, wherein said sensor is an optical sensor that detects the opacity of said wastewater in said aeration tank.

### Claim 9 (depends on 6)

The wastewater treatment system of claim 6, wherein said inlet of said pretreatment tank includes a flow meter.

### Claim 10 (depends on 9)

The wastewater treatment system of claim 9, wherein said control panel pulses said recirculation pump when said sensor sends a signal that said suspended solids in said aeration tank exceed a predetermined level.

### Claim 11 (depends on 10)

The wastewater treatment system of claim 10, wherein said sensor is an optical sensor that detects the opacity of said wastewater in said aeration tank.