# US 11,993,799 B1 · Method for preparing carbon source for wastewater treatment by using kitchen waste

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- Number: US 11,993,799 B1
- Document ID: US11993799B1
- Status: Granted
- Kind: B1
- Application number: 18/499,231
- Filed: 2023-11-01
- Granted: 2024-05-28
- Earliest claimed: 2022-12-28
- Assignees: Hangzhou Nanda Environmental Protection Technology Co., Ltd
- Applicants: Hangzhou Nanda Environmental Protection Technology Co., Ltd
- Inventors: Jianlin Xu; Bin Gu; Yuan Fu; Zhenggeng Qiu
- Web page: https://patentgrep.com/patent/US11993799B1

## CPC

- C12P 1/04: by using bacteria
- B09B 3/60: Biochemical treatment, e.g. by using enzymes
- C02F 3/00: Biological treatment of water, waste water, or sewage {(C02F1/006 takes precedence)}
- C02F 3/1263: {Sequencing batch reactors [SBR]}
- C02F 3/341: {Consortia of bacteria}
- C02F 2305/06: Nutrients for stimulating the growth of microorganisms
- Y02W 10/10: Biological treatment of water, waste water, or sewage
- C12P: FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE {(brewing of beer C12C; producing vinegar C12J; producing specific peptides or proteins C07K; producing enzymes C12N9/00; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; measuring or testing processes involving enzymes or microorganisms C12Q; measuring or testing processes involving nucleic acid amplification reactions C12Q1/6844; fermentation processes to form a food composition, A21 or A23; compounds in general, see the relevant compound class, e.g. C01, C07)}
- B09B: DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR
- 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 for preparing a carbon source for wastewater treatment by using kitchen waste, comprises: adding a complex microbial inoculant into the kitchen waste; and phase-change degrading the kitchen waste into a phase-change liquid under aerobic fermentation of the complex microbial inoculant; wherein the phase-change liquid is the carbon source for wastewater treatment; the complex microbial inoculant comprises: a microbial agent comprising aerobic bacteria; and an excipient comprising an Fe-based MOF (metal-organic framework) nanocomposite. According to the method, the kitchen waste is treated under aerobic fermentation to prepare the carbon source, a carbon-nitrogen ratio is greater than 40, and the carbon source is used to supplement a carbon source in a sewage treatment process of a sewage plant, which significantly improves nitrogen and phosphorus removal effects of sewage treatment in the sewage plant, and provides theoretical foundation and basis for resource utilization of the kitchen waste.

## Claims

### Claim 1

A method for preparing a carbon source for wastewater treatment by using kitchen waste, comprising:
adding a complex microbial inoculant into the kitchen waste; and
phase-change degrading the kitchen waste into a phase-change liquid under aerobic fermentation of the complex microbial inoculant; wherein the phase-change liquid is the carbon source for wastewater treatment;
the complex microbial inoculant comprises: a microbial agent comprising aerobic bacteria; and an excipient comprising an Fe-based metal-organic framework (MOF) nanocomposite;
the Fe-based MOF nanocomposite is prepared by the following steps:
mixing an Fe-based metal-organic framework and graphene oxide, performing one-step solvothermal synthesis to obtain Fe-MOF@GO, and then mixing the Fe-MOF @GO with N-(n-butyl) thiophosphoric triamide and performing high-temperature treatment to obtain the Fe-based MOF nanocomposite.

### Claim 2 (depends on 1)

The method according to claim 1, wherein a mass ratio of the microbial agent to the excipient is 1:(3-10).

### Claim 3 (depends on 1)

The method according to claim 1, wherein the microbial agent comprises 10-16 parts of Bacillus licheniformis, 15-20 parts of Bacillus subtilis, 8-14 parts of yeast and 10-15 parts of Pediococcus acidilactici in parts by weight.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the method specifically comprises the following steps:
sorting and removing sundries from the kitchen waste, adding water according to a solid-liquid ratio of 1 g: (1-1.2) mL to obtain a mixture, placing the mixture in a pulverizer for crushing and pulping, filtering with a filter screen, heating the filtered kitchen waste slurry for 30-60 min at 75-90° C., and extracting and removing 70%-80% of waste grease with a three-phase separator;
adding the complex microbial inoculant into the kitchen waste slurry, adjusting an initial pH value to 6.5-7.2, performing open fermentation at 35-45° C. for 4-6 d; and
centrifuging the fermented material for 10-15 min at 4000-4200 rpm for solid-liquid separation, and taking a supernatant; wherein the supernatant is the carbon source for wastewater treatment.

### Claim 5 (depends on 1)

The method according to claim 1, wherein a carbon-nitrogen ratio of the carbon source for wastewater treatment is greater than 40:1.

### Claim 6 (depends on 1)

The method according to claim 1, wherein in the carbon source for wastewater treatment, a chemical oxygen demand (COD) content is 20000-40000 mg/L, a NH4+—N content is 200-600 mg/L, a total nitrogen (TN) content is 300-500 mg/L, and a total phosphorus (TP) content is 30-50 mg/L.

### Claim 7 (depends on 1)

An application of the Fe-based MOF nanocomposite prepared by the method according to claim 1 in preparing the complex microbial inoculant for degradation of the kitchen waste.

### Claim 8 (depends on 1)

An application of the Fe-based MOF nanocomposite prepared by the method according to claim 1 in preparing the carbon source for wastewater treatment.