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CN-119551858-B - Method for simultaneously removing ammonia nitrogen and organic pollutants in landfill leachate

CN119551858BCN 119551858 BCN119551858 BCN 119551858BCN-119551858-B

Abstract

The application belongs to the technical field of wastewater treatment, and relates to a method for simultaneously removing ammonia nitrogen and organic pollutants in landfill leachate. The method aims at solving the technical problems that the high-concentration ammonia nitrogen and organic pollutants in the landfill leachate in the prior art have poor removal effect, limit the subsequent biochemical treatment effect and easily cause huge impact on a biochemical treatment system. The application provides a method for simultaneously removing ammonia nitrogen and organic pollutants in landfill leachate, which comprises the steps of carrying out struvite crystallization reaction on the landfill leachate, carrying out solid-liquid separation after gravity sedimentation to obtain upper liquid and crystals, regulating the pH value of the upper liquid to 2.0-3.0, adding Schleman mineral and H 2 O 2 , wherein the addition amount of the Schleman mineral is 2-20 g/L, and the addition amount of V (H 2 O 2 )/m (Schleman mineral) is 0.25-5 mL/g, carrying out photocatalytic reaction at constant temperature to obtain photocatalytic reaction liquid, and filtering to obtain the landfill leachate. The method greatly removes ammonia nitrogen and organic pollutants in advance before the landfill leachate enters the biochemical treatment, improves the biodegradability of the landfill leachate, reduces the impact load of the biochemical treatment, and simplifies the whole process flow.

Inventors

  • ZHOU LIXIANG
  • WANG HERU
  • LIU XUAN
  • HU HONGBIN

Assignees

  • 南京贝克特环保科技有限公司

Dates

Publication Date
20260508
Application Date
20241223

Claims (7)

  1. 1. The method for simultaneously removing ammonia nitrogen and organic pollutants in the landfill leachate is characterized by comprising the following steps of: performing struvite crystallization reaction on the landfill leachate to obtain landfill leachate containing crystals; performing solid-liquid separation on the landfill leachate containing crystals after gravity sedimentation to obtain upper liquid and crystals; Regulating the pH value of the upper liquid to 2.0-3.0, adding Schlemen mineral and H 2 O 2 , wherein the addition amount of the Schlemen mineral is 2 g/L-20 g/L, V (H 2 O 2 )/m (Schlemen mineral) is 0.25 mL/g-5 mL/g, carrying out photocatalytic reaction at constant temperature to obtain photocatalytic reaction liquid, and filtering the photocatalytic reaction liquid to obtain liquid for removing ammonia nitrogen and organic pollutants; Phosphate is added in the struvite crystallization reaction, and after dissolution, a magnesium source is added, wherein the phosphate is Na 2 HPO 4 ·12H 2 O, and the magnesium source is MgCl 2 ·6H 2 O; The addition amount of Na 2 HPO 4 ·12H 2 O and MgCl 2 ·6H 2 O is determined according to the nitrogen content in the landfill leachate, and the molar ratio of nitrogen, phosphorus and magnesium is X:Y:Z=1:1:1.
  2. 2. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to claim 1, wherein the struvite crystallization reaction is carried out in a shaking table, and the rotating speed of the shaking table is 150 r/min-200 r/min for 30 min-60 min.
  3. 3. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to claim 1, wherein the light source used in the photocatalytic reaction is ultraviolet light, and the intensity of the ultraviolet light is 300-500W.
  4. 4. The method for simultaneously removing ammonia nitrogen and organic pollutants in landfill leachate according to claim 1, wherein the constant temperature is 25-35 ℃ and the time is 2-3 hours.
  5. 5. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to any one of claims 1 to 4, wherein the initial pH value of the landfill leachate is 7.5 to 11.0, the initial ammonia nitrogen concentration is 750 mg/L to 800 mg/L, the initial COD concentration is 10000 mg/L to 12000 mg/L, the initial TOC concentration is 400 mg/L to 500 mg/L and the chroma is 50 times.
  6. 6. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to claim 5, wherein the initial pH value is adjusted to 7.5-11.0 by using HCl solution and/or NaOH solution with a molar concentration of 1M.
  7. 7. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to claim 5, wherein the Schlemen mineral is recovered in the filtering step.

Description

Method for simultaneously removing ammonia nitrogen and organic pollutants in landfill leachate Technical Field The invention belongs to the technical field of wastewater treatment, and particularly relates to a method for simultaneously removing ammonia nitrogen and organic pollutants in landfill leachate. Background In recent years, the production of domestic garbage in China is greatly increased, more than eight kinds of garbage are finally disposed through sanitary landfill, but secondary pollutant garbage percolate is easily generated in the landfill process due to factors such as decomposition of organic pollutants in the domestic garbage, rainwater immersion, self water content and the like. The most obvious characteristics of the landfill leachate are high ammonia nitrogen, high organic pollutants and high chromaticity, and also contain a large number of pathogenic microorganisms, so that the quality of soil, surface water and groundwater is greatly threatened, and the safe and harmless treatment of the landfill leachate is particularly important. Although the technology of the traditional sewage biochemical treatment process is mature, a biochemical system is difficult to accept high ammonia nitrogen and high organic pollutant load impact for a long time, and effluent is difficult to reach the standard stably, and even the system is crashed. If ammonia nitrogen and organic pollutants with high concentration in the landfill leachate are removed greatly in advance and then enter a biochemical treatment system, the effluent can be ensured to reach the standard and be stable. The Chinese patent application publication No. CN118388089A, the application date is 2024 and 06 month 18, the invention is named as a full quantification treatment process of percolate based on Fenton treatment, the disclosed treatment process comprises the steps of firstly carrying out ammonia stripping on landfill leachate, pumping into an iron-carbon Fenton pond for Fenton reaction, removing part of ammonia nitrogen and organic pollutants by utilizing the two steps, carrying out biochemical treatment by an anaerobic baffling-biological contact-aeration biological method, carrying out Fenton reaction on biochemical treatment effluent again for further removing the organic pollutants, then adding a coagulant (PAC and PAM) for coagulating sedimentation, and finally introducing the landfill leachate after coagulating sedimentation into an electrolytic tank for treatment. Although the method can safely and harmlessly treat the landfill leachate, the method has some disadvantages which cannot be ignored. Firstly, the pH value of the leachate is lower than 10, the ammonia stripping efficiency is low, secondly, the method involves two Fenton reactions, more iron mud is produced and is difficult to treat, furthermore, the biochemical treatment effluent still needs to be subjected to coagulating sedimentation and electrolytic treatment, the process flow is complex, the debugging difficulty is high, the use amount of chemical agents is high, and the operation and maintenance cost is high. The biochemical treatment effluent still needs Fenton reaction, coagulating sedimentation and electrolysis to achieve the purpose of further removing ammonia nitrogen and organic pollutants, and finally the front ammonia stripping and Fenton reaction still has limited effect of removing ammonia nitrogen and organic pollutants, thereby limiting biochemical treatment effect. Therefore, finding a pretreatment method for efficiently removing high-concentration ammonia nitrogen and organic pollutants in the landfill leachate has great significance in treating the landfill leachate. Disclosure of Invention 1. Problems to be solved Aiming at the technical problems that the high-concentration ammonia nitrogen and organic pollutants in the landfill leachate have poor removal effect, the subsequent biochemical treatment effect is limited, and the impact on a biochemical treatment system is easy to cause in the prior art, the application provides a method for simultaneously removing the ammonia nitrogen and the organic pollutants in the landfill leachate, which combines a struvite crystallization method and a photocatalytic oxidation method to remove the ammonia nitrogen and the organic pollutants in the landfill leachate, and the ammonia nitrogen and the organic pollutants are removed greatly in advance before the landfill leachate enters the biochemical treatment, so that the biodegradability of the landfill leachate is improved, the impact load on the biochemical treatment can be reduced, the whole process flow is simplified, and the intervention of the advanced treatment is eliminated. 2. Technical proposal In order to achieve the above purpose, the technical scheme provided is as follows: The method for simultaneously removing ammonia nitrogen and organic pollutants in the landfill leachate comprises the following steps: performing struvite crystallization re