CN112110601A

CN112110601A - Method and device for treating landfill leachate

Info

Publication number: CN112110601A
Application number: CN201910529621.1A
Authority: CN
Inventors: 祝来宏
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-06-19
Filing date: 2019-06-19
Publication date: 2020-12-22

Abstract

The invention relates to the technical field of sewage treatment, and mainly relates to a method and a device for treating landfill leachate, wherein the method comprises the following steps: acid separation and slag scraping, air flotation slag removal and dynamic membrane filter slag removal treatment. The scum enters a sludge pool, is mixed with alkaline sludge and then enters a filter press for filter pressing. The leachate after deslagging contains higher content of particles, the leachate enters a dynamic mode filter for filtering, filtered water enters an iron-carbon micro-electrolysis fluidized bed, hydrogen peroxide is added into effluent of the fluidized bed for Fenton oxidation, trinuclear water purifying agent is added after the Fenton oxidation to adjust the PH value to be 7.0-7.5 for reaction, hypochlorous acid is added according to the concentration of ammonia nitrogen in the leachate to perform breakpoint chlorination to remove ammonia nitrogen, after the reaction is completed, the trinuclear water purifying agent is used for adjusting the PH value to be more than 11.0 for coagulation precipitation, supernatant liquid is subjected to blow-off according to whether the concentration of ammonia nitrogen in the effluent is adopted to further reduce ammonia nitrogen, supernatant liquid after the coagulation precipitation or supernatant liquid after ammonia nitrogen blow-off is subjected to PH value adjustment and then enters a biochemical system for subsequent anaerobic, aerobic and submerged membrane filtered water is discharged until the effluent reaches the standard.

Description

Method and device for treating landfill leachate

The technical field is as follows:

the invention relates to a method and a device for treating landfill leachate, belonging to the field of treatment of waste liquid and sewage.

Background art:

the landfill leachate has high pollution load, comprises various pathogenic microorganisms, carcinogenic organic matters and the like, wherein organic species are extremely complex, ammonia nitrogen and heavy metal contents are high, the change of water quality is large due to the influence of a plurality of external environments such as the landfill time and the annual rainfall, and the treatment difficulty is extremely high. In order to pursue new technical innovation and improve the harmless treatment efficiency of the municipal solid waste leachate, the development of a sustainable treatment method which has high treatment efficiency, strong universality and convenient operation and does not have the open loop of returning the concentrated solution to the tank is urgent need of the market. The conventional treatment method of the landfill leachate mainly comprises the following steps: chemical methods, biological methods and membrane methods are combined, but the treatment methods generally comprise chemical weakening treatment and membrane strengthening treatment, and although the effluent quality is ensured, the effluent quantity is low, the investment cost is high, a large amount of concentrated solution is generated and needs to be returned to a tank, so that vicious circle is caused, and the treatment is difficult to form virtuous circle.

The invention content is as follows:

the technical problem solved by the invention is as follows: the method for treating the landfill leachate is sustainable, universal, strong in plasticity and easy to control. The invention provides a method for treating landfill leachate, which sequentially comprises the following steps:

1. adding acidic high-valence compound to adjust pH of percolate to 3.0-4.0, performing acid precipitation, and dissolving out surfactant, oil and lipid in percolate. 2. And scraping the acid-out dissolved-out substances to a sludge tank by using a slag scraper. 3. And lifting the leachate after the acidification separation to an air flotation tank, and adding a micelle coagulant to be mixed with the leachate for dissolved air. 4. And discharging the oil, grease and surfactant floated by the air to a sludge concentration tank by using a residue scraper. 5. The effluent of the air floatation tank enters a dynamic membrane filter for filtration. 6. And after filtration, the effluent enters an iron-carbon micro-electrolysis fluidized bed for micro-electrolysis oxidation reaction. 7. Adding hydrogen peroxide into effluent after micro-electrolysis oxidation to perform Fenton oxidation reaction, and adjusting the adding amount of the hydrogen peroxide according to the concentration of pollutants, wherein more hydrogen peroxide can be added when the concentration is high. 8. After Fenton oxidation, pH is adjusted to 7.0-7.5 by using a trinuclear water purifying agent for coagulating sedimentation. 9. And (3) after the coagulating sedimentation, feeding the effluent into a secondary reaction tank, adding sodium hypochlorite to carry out breakpoint chlorination reaction, adjusting the adding amount of the sodium hypochlorite according to the concentration of the ammonia nitrogen content, and ensuring the complete reaction. 10. After the second-stage reaction is completed, trinuclear water purifying agent is added to regulate the pH value to be more than 11.0, and then coagulation precipitation is carried out to remove heavy metals. 11. When the water quality is changed greatly and the ammonia nitrogen content is high, the amount of hypochlorous acid can be increased, and the effluent after the secondary coagulation sedimentation can be subjected to ammonia stripping treatment, so that the influence of the ammonia nitrogen on the subsequent biochemistry is further reduced. 12. And (3) adjusting the PH of the effluent of the secondary coagulation sedimentation or the effluent after ammonia nitrogen stripping back to a neutral state, and then performing anaerobic, facultative and aerobic reaction, and achieving the purpose of deep treatment by adding a carbon source and adjusting the reflux ratio. 13. And (3) introducing effluent of the process biochemical system into an immersed MBR membrane reactor, and siphoning to discharge the effluent. 14. And (4) enabling the effluent of the immersed MBR membrane to enter a discharge system to be discharged after reaching the standard.

Has the advantages that:

the whole treatment process of the invention is progressive layer by layer, and the dosage, the reaction time, the reflux ratio and the filtration precision can be correspondingly adjusted according to the concentration change of pollutants, and the water quality change caused by seasonal changes. Can always keep high-efficiency operation. The invention emphasizes the pretreatment before the biochemical treatment, improves the biodegradability of the pretreated percolate, greatly reduces the biological toxicity and provides reliable technical guarantee for qualified and standard effluent.

Claims

1. A method for treating landfill leachate is characterized by comprising the following steps:

adding an acidic high-valence compound into leachate for acidification, reacting a large amount of anionic organic matters in the leachate with the high-valence compound, dissolving out, lifting the effluent of acidification to an air flotation machine for dissolved air flotation, lifting the effluent after air flotation to a dynamic membrane filter for filtration, discharging the filtered effluent into an iron-carbon micro-electrolysis fluidized bed, adding hydrogen peroxide into the effluent of the fluidized bed for Fenton oxidation, adjusting the pH of the effluent after Fenton oxidation to about 7.0 by using a trinuclear water purifying agent, then adding hypochlorous acid for breakpoint chlorination reaction, adding the trinuclear water purifying agent after reaction to adjust the pH to be more than 11.0, introducing the effluent into a stripping tower for denitrification, adjusting the pH of the effluent to a neutral biochemical system, performing anaerobic, facultative and aerobic MBR biochemical treatment, introducing the effluent into an immersed membrane system, and introducing the effluent of the MBR into a discharge port for discharge up to the standard.

2. The integrated wastewater treatment process for electroplating according to claim 1, wherein: the acidic high-valence compound is added into the leachate for acidification, so that a large amount of anionic organic matters in the leachate react with the high-valence compound and are dissolved out.

3. The integrated wastewater treatment process for electroplating according to claim 1, wherein: and lifting the effluent after acid precipitation to an air flotation tank for dissolved air flotation.

4. The integrated wastewater treatment process for electroplating according to claim 1, wherein: and lifting the effluent after air floatation to a dynamic membrane filter, and discharging the filtered water of the dynamic membrane into the iron-carbon micro-electrolysis fluidized bed.

5. The integrated wastewater treatment process for electroplating according to claim 1, wherein: adding hydrogen peroxide into the effluent of the fluidized bed for Fenton oxidation.

6. The integrated wastewater treatment process for electroplating according to claim 1, wherein: after the Fenton oxidation is finished, adjusting the pH of the effluent to be about 7.0 by using a trinuclear water purifying agent, adding hypochlorous acid to perform a breakpoint chlorination reaction, and adding the trinuclear water purifying agent into the effluent after the reaction to adjust the pH to be about 11.0.

7. The integrated wastewater treatment process for electroplating according to claim 1, wherein: and (3) reacting the effluent after the pH value is adjusted, then denitrifying the effluent in a stripping tower, and adjusting the pH of the effluent after denitrification to be neutral to enter a biochemical system for anaerobic, facultative and aerobic biochemical treatment.

8. The integrated wastewater treatment process for electroplating according to claim 1, wherein: and (4) the biochemical wastewater enters an immersed MBR membrane system.

9. The integrated wastewater treatment process for electroplating according to claim 1, wherein: and (4) enabling outlet water of the MBR membrane system to enter a discharge port to be discharged after reaching the standard.