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CN-121974499-A - Method for rapidly denitrifying carbon quantum dot-assisted microorganisms in high-turbidity biogas slurry and application thereof

CN121974499ACN 121974499 ACN121974499 ACN 121974499ACN-121974499-A

Abstract

The invention belongs to the technical field of wastewater purification, and particularly relates to a method for rapidly denitrifying carbon quantum dot-assisted microorganisms in high-turbidity biogas slurry and application thereof. The invention comprises the steps of inoculating microalgae in biogas slurry, adding carbon quantum dots, uniformly mixing to construct a purification system, continuously irradiating the purification system with visible light, simultaneously introducing mixed gas of carbon dioxide and air, and carrying out photosynthetic denitrification purification treatment on the biogas slurry. The invention solves the technical problems that the photosynthesis of microalgae is inhibited, the electron transfer of microorganisms is slow, the recovery of nano materials is difficult and the like in the existing purification of wastewater (especially biogas slurry).

Inventors

  • ZHU SHUN
  • LIAO QIANG
  • JIA ZIYU
  • HUANG YUN
  • Xia ao
  • ZHU XIANQING
  • ZHANG JINGMIAO

Assignees

  • 重庆大学

Dates

Publication Date
20260505
Application Date
20260327

Claims (9)

  1. 1. A method for rapidly denitrifying carbon quantum dot-assisted microorganisms in biogas slurry is characterized by comprising the following steps: inoculating microalgae in the biogas slurry, adding carbon quantum dots, uniformly mixing, and constructing a purification system; and (3) continuously irradiating the purification system with visible light, introducing gas, and performing photosynthetic denitrification purification treatment on the biogas slurry.
  2. 2. The method of claim 1, wherein the microalgae is inoculated in an amount of 0.01-1 g/L; And/or, the microalgae comprises at least one of chlorella, chlamydomonas and scenedesmus; And/or the addition amount of the carbon quantum dots is 0-1 g/L and is not 0.
  3. 3. The method of claim 1, wherein the preparing of the carbon quantum dots comprises: And uniformly mixing biomass powder and an ethanol water solution, performing hydrothermal reaction, and then centrifuging, dialyzing, filtering and drying to obtain the carbon quantum dots.
  4. 4. The method of claim 3, wherein the mass to volume ratio of biomass powder to aqueous ethanol solution is 1g (10-200) mL; And/or the volume fraction of the ethanol aqueous solution is 0-100%; and/or the temperature of the hydrothermal reaction is 120-300 ℃ and the time is 4-24 h; and/or, the dialysis is carried out in water by using a 3500 Da dialysis bag, the dialysis time is 3 days, and the water is replaced every 7 hours; and/or, the filtration is through a 0.22 μm filter; and/or the biomass comprises at least one of agriculture and forestry waste, food processing waste and microalgae recovered after biogas slurry purification.
  5. 5. The method of claim 1, wherein the continuous visible light illumination has an illumination intensity of 0 to 1000 μmol seed m -2 ・s -1 and is other than 0.
  6. 6. The method of claim 1, wherein the gas is carbon dioxide to air in a volume ratio of 0-60:40-100.
  7. 7. The method of claim 1, wherein the aeration rate of the mixed gas of carbon dioxide and air is from 0 to 0.5 vvm and not 0.
  8. 8. The method of claim 1, further comprising recovering microalgae after photosynthetic denitrification purification treatment, drying to constant weight, and grinding into algae powder for preparing carbon quantum dots.
  9. 9. The application of the carbon quantum dots in the suspended microalgae biogas slurry purification system is characterized in that the addition amount of the carbon quantum dots is 0-1 g/L, and the addition amount is not 0.

Description

Method for rapidly denitrifying carbon quantum dot-assisted microorganisms in high-turbidity biogas slurry and application thereof Technical Field The invention belongs to the technical field of wastewater purification, and particularly relates to a method for rapidly denitrifying carbon quantum dot-assisted microorganisms in high-turbidity biogas slurry and application thereof. Background The high-speed development of animal husbandry brings a large amount of livestock and poultry manure, and the biogas engineering can realize the resource utilization of wastes, so that the method is one of effective ways for solving the problem, but biogas slurry generated in the biogas production process causes environmental hazard and needs to be treated urgently. The common wastewater purification mainly adopts a physical and chemical method, but the common wastewater purification has the problems of high cost, high energy consumption and the like. Anaerobic digestion biogas slurry has the characteristics of low carbon nitrogen ratio and high nutrient concentration, and the biological purification of the wastewater has remarkable prospect. The microalgae has great application potential in the field of biogas slurry purification by virtue of low energy consumption and high pollutant removal efficiency. However, the high ammonia nitrogen characteristic of the biogas slurry can inhibit photosynthesis of microalgae, a large amount of suspended solids in the biogas slurry can cause light attenuation, the high turbidity characteristic greatly limits the utilization of microalgae to light, the photosynthesis autotrophic growth capacity of the microalgae is reduced, and the purification efficiency of the biogas slurry is further reduced. The content of organic suspended solids in the biogas slurry is reduced, so that the turbidity can be reduced, and the light attenuation phenomenon can be relieved. Bacteria in biogas slurry can degrade organic suspended matters into small molecular substances for microorganisms to use, but slow electron transfer rate of the microorganisms is a core bottleneck which restricts the process efficiency. Electron transfer is a key process of purifying biogas slurry by microorganisms, and directly affects energy metabolism and material conversion rate of microbial communities. Due to the excellent photoelectric characteristics, the nano material not only can promote the electron transfer of microorganisms, but also can participate in energy metabolism to promote the biodegradation efficiency and accelerate the conversion and utilization of waste resources. However, the existing nano material has the problems of high recovery difficulty, high cost and low subsequent utilization efficiency, and the large-scale application of the nano material in the field of biogas slurry treatment is limited. Disclosure of Invention The invention provides a method for quickly denitrifying microorganisms in high-turbidity biogas slurry by using carbon quantum dots and application thereof, which are particularly suitable for purifying the biogas slurry with high ammonia nitrogen and high suspended solid content, and aims to solve the technical problems that the photosynthesis of microalgae is inhibited, the microbial electron transfer is slow, the recovery of nano materials is difficult and the like in the existing purification of wastewater (particularly biogas slurry). In order to achieve the above object, the present invention provides the following solutions: According to one of the technical schemes, the invention provides a method for rapidly denitrifying microorganisms in biogas slurry by using carbon quantum dots, which comprises the following steps: inoculating microalgae in the biogas slurry, adding carbon quantum dots, uniformly mixing, and constructing a purification system; and (3) continuously irradiating the purification system with visible light, introducing gas, and performing photosynthetic denitrification purification treatment on the biogas slurry. Further, the inoculation amount of the microalgae is 0.01-1 g/L, preferably 0.1 g/L. Further, the microalgae include at least one of chlorella, chlamydomonas and scenedesmus, preferably chlorella. Further, the addition amount of the carbon quantum dots is 0-1 g/L, and is not 0, preferably 0.03 g/L. Further, the preparation steps of the carbon quantum dots include: And uniformly mixing biomass powder and an ethanol water solution, performing hydrothermal reaction, and then centrifuging, dialyzing, filtering and drying to obtain the carbon quantum dots. Alternatively, the mass to volume ratio of the biomass powder to the ethanol aqueous solution is 1g (10-200 mL), preferably 1g:60 mL. Optionally, the volume fraction of the ethanol aqueous solution is 0-100%. Optionally, the temperature of the hydrothermal reaction is 120-300 ℃ and the time is 4-24 h. Preferably, the temperature of the hydrothermal reaction is 180 ℃ and the time is 6 h. Alternatively, the di