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CN-118652004-B - Treatment method for pre-acidification of high-alkalinity wastewater and treatment device system thereof

CN118652004BCN 118652004 BCN118652004 BCN 118652004BCN-118652004-B

Abstract

The invention relates to a treatment method for pre-acidification of high-alkalinity wastewater and a treatment device system thereof, wherein the treatment method comprises the steps of adding nutrient substances into wastewater to be treated and carrying out adjustment treatment to obtain adjusted water; and (3) returning one part of the regulated water to perform regulation treatment, adding nutrient substances into the other part of the regulated water, and performing pre-acidification treatment to obtain pre-acidification water, performing anaerobic purification treatment on the pre-acidification water to obtain anaerobic purified water, and sequentially performing aeration treatment and precipitation treatment on the anaerobic purified water to obtain treated water. The treatment method and the treatment device system thereof can reduce the inhibition effect of waste water alkalinity and metal ions on anaerobic microorganisms by regulating and controlling the metabolic activity of the microorganisms, improve the anaerobic removal rate of anaerobic purification treatment, and reduce the adding cost of acidic substances and nutrient substances.

Inventors

  • LIU MINGZHONG
  • ZHANG WANXING
  • ZHANG YIAN
  • Zhai Xiaotang
  • SUN DONGYUE
  • YAN TIAN
  • Wu Taiyun
  • Peng Gangren
  • ZHANG CHANGMING
  • LIU MAOHUAN

Assignees

  • 玖龙纸业（东莞）有限公司

Dates

Publication Date
20260508
Application Date
20240717

Claims (20)

  1. 1. A method for treating high alkalinity wastewater by pre-acidification, which is characterized by comprising the following steps: (1) Adding nutrient substances into the wastewater to be treated, and performing adjustment treatment to obtain adjusted water; (2) Returning one part of the regulated water obtained in the step (1) to carry out regulation treatment, adding nutrient substances into the other part of the regulated water, and carrying out pre-acidification treatment to obtain pre-acidified water; (3) Performing anaerobic purification treatment on the pre-acidified water obtained in the step (2) to obtain anaerobic purified water; (4) Sequentially carrying out aeration treatment and precipitation treatment on the anaerobically purified water obtained in the step (3) to obtain treated water; wherein the pH value of the wastewater to be treated in the step (1) is more than or equal to 9; The nutrient comprises a nitrogen source and/or a phosphorus source; In the regulation treatment, the ratio of COD concentration, the adding amount of nitrogen and the adding amount of phosphorus in the wastewater is (250-500) 5:1; In the pre-acidification treatment, the ratio of COD concentration, the adding amount of nitrogen and the adding amount of phosphorus in the wastewater is (250-500) 5:1; And (3) returning the water quantity which is subjected to the adjustment treatment in the step (2) to 25-35% of the total water after adjustment.
  2. 2. The method according to claim 1, wherein the concentration of Fe 3+ in the wastewater to be treated is 1-3mg/L.
  3. 3. The method according to claim 1, wherein the concentration of Ca 2+ in the wastewater to be treated is 300-700mg/L.
  4. 4. The method according to claim 1, wherein the COD concentration of the wastewater to be treated is 6000-30000mg/L.
  5. 5. The process according to claim 1, wherein the temperature of the wastewater to be treated is 30-70 ℃.
  6. 6. The process of claim 1, wherein the pH of the conditioned water of step (1) is from 6 to 8.9.
  7. 7. The method according to claim 1, wherein the conditioned water is subjected to filtration and heat exchange in this order.
  8. 8. The process of claim 7, wherein the filter screen has a pore size of 1-3mm.
  9. 9. The process according to claim 1, wherein the temperature of the pre-acidified wastewater is 38-40 ℃.
  10. 10. The process of claim 1, wherein the conditioning treatment is followed by sludge generation.
  11. 11. The method according to claim 10, wherein the sludge produced by the conditioning treatment is fed into the sludge treatment unit via a slag discharge line.
  12. 12. The process of claim 1, wherein the pH of the pre-acidified water of step (2) is from 6 to 7.
  13. 13. The process according to claim 1, wherein the concentration of Fe 3+ in the pre-acidified water is 0-1.1mg/L.
  14. 14. The process according to claim 1, wherein the concentration of Ca 2+ in the pre-acidified water is 250-440mg/L.
  15. 15. The process of claim 1, wherein the pre-acidification treatment is followed by sludge production.
  16. 16. The method according to claim 15, wherein the sludge produced by the pre-acidification treatment is fed into the sludge treatment unit via a slag discharge line.
  17. 17. The process of claim 1, wherein the pH of the treated water of step (4) is from 7 to 9.
  18. 18. The method according to claim 1, wherein the COD concentration of the treated water is 150-250mg/L.
  19. 19. A treatment device system for pre-acidification of high alkaline wastewater, characterized in that the treatment device system is used in a treatment method for pre-acidification of high alkaline wastewater according to any one of claims 1 to 18; The treatment device system comprises an adjusting tank, a pre-acidification tank, an anaerobic reactor, an aeration tank, a secondary sedimentation tank and a secondary sedimentation water tank which are sequentially connected along the flow direction of wastewater; the inlet of the regulating tank is respectively connected with a waste water pipeline to be treated and a nutrient substance adding pipeline; the inlet of the pre-acidification tank is also connected with a nutrient substance adding pipeline; The water outlet main pipe of the regulating tank is respectively connected with inlets of the pre-acidification tank and the regulating tank; The secondary sedimentation water tank is connected with a treated water drainage pipeline.
  20. 20. The treatment device system of claim 19, wherein the drain of the conditioning tank is connected to a first water outlet line and a second water outlet line, respectively.

Description

Treatment method for pre-acidification of high-alkalinity wastewater and treatment device system thereof Technical Field The invention relates to the technical field of sewage treatment, in particular to a method for pre-acidification treatment of high-alkalinity wastewater and a treatment device system thereof. Background With the reduction of the external waste import limit, the high-quality waste paper resources face the trend of shortage, and the papermaking industry can only select domestic waste paper as raw material. However, as domestic waste paper is recycled for a long time, the pulping waste water has more complex components and higher pH value, and causes potential harm to environment and biological strains, thereby increasing the difficulty of waste water treatment. The highly alkaline wastewater contains various alkaline substances, such as NaOH, na 2CO3 and the like, and the existence of the substances leads the pH value of the wastewater body to be far higher than the normal value, generally more than 9 and possibly more than 12. In addition, because of the presence of alkaline substances, the wastewater may also contain heavy metal ions, organic matters and the like, further resulting in highly alkaline wastewater having complex chemical properties. The alkalinity and harmful substances of the high alkaline wastewater can inhibit anaerobic bacteria in the existing anaerobic treatment system, when the pH value of water body entering the anaerobic system exceeds the active range of the anaerobic bacteria, the removal rate of an anaerobic section can be reduced linearly, pollutants can not be degraded effectively, and environmental protection hidden danger exists. At present, a chemical precipitation method and an acid-base neutralization method are main methods for treating high alkaline wastewater, and chemical reagents are added into the wastewater, sulfide, hydroxide and the like are generally adopted to precipitate harmful substances and separate the harmful substances from a water body, but the method is easy to cause secondary pollution, and the inhibition effect of the sulfide on anaerobic bacteria is stronger and irreversible. The acid-base neutralization method is to neutralize the alkaline substances in the wastewater by adding acidic substances, generally sulfuric acid, hydrochloric acid and the like, to the wastewater, so as to achieve the purpose of reducing the pH value of the wastewater, but the method cannot provide nutrient substances required by anaerobic bacteria for degrading pollutants, and the addition of the acidic substances leads to the increase of treatment cost. Therefore, the method for pre-acidification treatment of the high-alkalinity wastewater and the treatment device system thereof are technical problems which need to be solved in the prior art. Disclosure of Invention Compared with the prior art, the treatment method and the treatment device system thereof can reduce the inhibition effect of waste water alkalinity and metal ions on anaerobic microorganisms by regulating and controlling the metabolic activity of the microorganisms, improve the anaerobic removal rate of anaerobic purification treatment and reduce the adding cost of acidic substances and nutrient substances. In order to achieve the aim of the invention, the invention adopts the following technical scheme: In a first aspect, the invention provides a method for pre-acidification treatment of high alkalinity wastewater, the method comprising the steps of: (1) Adding nutrient substances into the wastewater to be treated, and performing adjustment treatment to obtain adjusted water; (2) Returning one part of the regulated water obtained in the step (1) to carry out regulation treatment, adding nutrient substances into the other part of the regulated water, and carrying out pre-acidification treatment to obtain pre-acidified water; (3) Performing anaerobic purification treatment on the pre-acidified water obtained in the step (2) to obtain anaerobic purified water; (4) Sequentially carrying out aeration treatment and precipitation treatment on the anaerobically purified water obtained in the step (3) to obtain treated water Aiming at the problems that the treatment of the high alkaline wastewater by adopting a chemical precipitation method is easy to cause secondary pollution and inhibit anaerobic bacteria, and the treatment cost is easy to increase by adopting an acid-base neutralization method, the invention adopts a microorganism treatment method, and utilizes the characteristics of hydrolytic bacteria in the original sewage treatment system, namely the hydrolytic bacteria are zymobacteria with hydrolytic capability, and the zymobacteria carry out hydrolysis by paying energy to obtain water-soluble substrates capable of fermentation, obtain energy sources through intracellular biochemical reaction and discharge metabolites. In the invention, in the stage of adjustment treatment and pre-acidificatio