Synchronous nitrogen and carbon removal method for high-salt landfill leachate in industrial park

Abstract

A synchronous nitrogen and carbon removal method for high-salt landfill leachate in an industrial park comprises the following steps: adding magnesium salt into the leachate to remove ammonia nitrogen and total phosphorus in the leachate; the method comprises the following steps of: adding a coagulant into the leachate, so that fine particles are condensed into relatively large particles, further enlarging and compacting the particles through a flocculating agent, forming rapidly-settled large floccules, removing ammonia nitrogen in the leachate, and adsorbing macromolecular organic matters in the leachate; thiosulfate enhanced persulfate advanced oxidation: adding an oxidizing agent into the leachate and generating sulfate free radicals to destroy the structure of organic matters and effectively degrade refractory organic matters; and adding a sodium hypochlorite oxidizing agent into the leachate to remove residual ammonia nitrogen and organic matters so as to ensure that pollutants in the leachate are basically removed. According to the invention, ammonia nitrogen, organic matters and heavy metals with high content in the high-salt industrial landfill leachate can be effectively removed, harmless treatment of the leachate is realized, the treatment efficiency is improved, and the treatment cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of industrial waste treatment, and in particular to a method for synchronously removing nitrogen and carbon from high-salt waste leachate in an industrial park. Background Art

[0002] With the rapid development of cities, the continuous increase in industrial production activities and the continuous improvement of people's living standards, the output of garbage and waste in industrial parks has also increased dramatically. At present, my country's industrial waste treatment is still mainly landfill disposal, and the leachate generated during the landfill process has become a global problem that needs to be dealt with urgently. Since its landfill is mainly construction waste or industrial waste, it has complex composition, high concentrations of pollutants such as organic matter and ammonia nitrogen, and contains high concentrations of heavy metals and toxic substances such as industrial production residues, it is difficult to treat.

[0003] At present, the treatment of high-salinity industrial waste leachate is mainly based on physical and chemical methods and biological methods. Among them, traditional biological methods such as activated sludge method have poor resistance to environmental stress for high-salinity wastewater, and microorganisms cannot adapt to the environmental conditions of high-salinity wastewater. They need to go through pretreatment processes such as coagulation, evaporation desalination and even dilution, which undoubtedly increases the treatment cost and treatment procedures of high-salinity wastewater; while physical and chemical methods such as coagulation, sedimentation, and filtration have limited treatment effects on organic matter and can usually only be used as pre-treatment or post-treatment processes. The treatment of high-salinity industrial waste leachate has become an industry-wide and global problem, which not only endangers the landfill safety of landfills, but also affects the stability of leachate treatment systems. Summary of the invention

[0004] Based on the above problems, the present invention provides a method for simultaneous denitrification and decarbonization of high-salt industrial waste leachate in industrial parks, which can effectively remove ammonia nitrogen, organic matter and heavy metals with high content in high-salt industrial waste leachate, realize the harmless treatment of leachate, improve the treatment efficiency of high-salt industrial waste leachate in industrial parks, and reduce the treatment cost.

[0005] A method for simultaneous denitrification and carbon removal of high-salt landfill leachate in an industrial park, comprising the following steps:

[0006] Step S1: struvite precipitation: adding magnesium salt to the leachate to remove ammonia nitrogen and total phosphorus in the leachate;

[0007] Step S2: iron-based coagulation: adding a coagulant to the leachate to agglomerate fine particles into larger particles, and then using a flocculant to further enlarge and compact the particles to form large flocs that settle quickly, further removing ammonia nitrogen from the leachate, and adsorbing macromolecular organic matter in the leachate, thereby reducing the load of subsequent treatment procedures;

[0008] Step S3: Thiosulfate-enhanced persulfate advanced oxidation: adding an oxidant to the leachate to generate sulfate free radicals, destroying the structure of organic matter and effectively degrading refractory organic matter;

[0009] Step S4: Advanced treatment: Add sodium hypochlorite oxidant to the leachate to further remove the remaining ammonia nitrogen and organic matter to ensure that the pollutants in the leachate are basically removed.

[0010] Preferably, in the struvite precipitation of step S1 of the present invention, the pH is adjusted to weak alkalinity before adding magnesium salt, and the ammonium magnesium phosphate crystals in the precipitate are recovered, thereby realizing the resource utilization of ammonia nitrogen and total phosphorus.

[0011] Preferably, the magnesium salt of the present invention is magnesium chloride.

[0012] Preferably, in the iron-based coagulation of step S2 of the present invention, the coagulant, the flocculant and the leachate are fully mixed by stirring under acidic conditions, and the floccules in the leachate after coagulation are settled by gravity to achieve solid-liquid separation. The generated sludge is dehydrated and dried, and the dried sludge is incinerated.

[0013] Preferably, the coagulant of the present invention is ferric chloride; and the flocculant is anionic polyacrylamide.

[0014] Preferably, in the thiosulfate-enhanced persulfate advanced oxidation in step S3 of the present invention, a sodium persulfate oxidation method is used, the pH is adjusted to neutral, and the organic matter: sodium persulfate: thiosulfate is added in a mass ratio of 1:18:0.18, and the iron ions introduced in step S2 are converted into ferrous ions by sodium thiosulfate, which activates the sodium persulfate oxidation, and the oxidant and the leachate are fully mixed by heating and stirring in the reactor, and the reaction time is generally 2h.

[0015] Preferably, in the deep treatment of step S4 of the present invention, sodium hypochlorite is used to treat the remaining organic matter and ammonia nitrogen, and sodium ions and chloride ions are introduced to be recycled in the subsequent evaporation and crystallization process. After the reaction is completed, the pH value is adjusted to neutral or weak alkaline with an alkaline solution (such as sodium hydroxide) to facilitate subsequent treatment.

[0016] Preferably, the alkaline solution of the present invention is sodium hydroxide.

[0017] The synchronous denitrification and carbon removal process for high-salt garbage leachate in an industrial park of the present invention utilizes the coupling of technologies such as struvite precipitation-iron-based coagulation-thiosulfate-enhanced persulfate advanced oxidation-deep treatment, and recovers most of the ammonia nitrogen and total phosphorus in the leachate through struvite precipitation, and then adsorbs macromolecular organic matter and ammonia nitrogen in the leachate through flocs formed in the iron-based coagulation process, thereby reducing the load of subsequent advanced oxidation, making it easier for sodium persulfate to oxidize organic matter in the leachate, and finally performing deep treatment through sodium hypochlorite, thereby achieving maximum denitrification and carbon removal of high-salt garbage leachate in the industrial park, thereby achieving the technical effect of improving treatment efficiency and reducing operating costs, and solving the technical problem that high-salt garbage leachate in the industrial park is difficult to treat. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic flow diagram of the simultaneous denitrification and carbon removal method of the present invention.

[0019] Figure 2 It is a three-dimensional fluorescence spectrum diagram of the removal effect of difficult-to-degrade organic matter in leachate using the simultaneous denitrification and carbon removal method of the present invention, wherein a is high-salt leachate, b is struvite precipitation, c is iron-based coagulation, d is thiosulfate-enhanced persulfate advanced oxidation, and e is deep treatment.

[0020] Figure 3 The figure is a UV-visible spectrum diagram of the removal effect of refractory organic matter in leachate using the simultaneous denitrification and carbon removal method of the present invention. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is described in detail below with reference to the accompanying drawings:

[0022] like Figure 1 As shown, a method for simultaneous denitrification and carbon removal of high-salt landfill leachate in an industrial park comprises the following steps:

[0023] Step S1: Struvite precipitation: adding magnesium salt to the leachate to remove ammonia nitrogen and total phosphorus in the leachate.

[0024] The pH is adjusted to weak alkalinity before adding magnesium salt, and the ammonium magnesium phosphate crystals in the precipitation are recovered, so as to realize the resource utilization of ammonia nitrogen and total phosphorus. The magnesium salt is magnesium chloride.

[0025] Step S2: Iron-based coagulation: Add a coagulant to the leachate to condense fine particles into larger particles, and then use a flocculant to further increase and compact the particles to form large flocs that settle quickly, further remove ammonia nitrogen from the leachate, and adsorb large molecular organic matter in the leachate, reducing the load of subsequent treatment procedures.

[0026] In the process, the coagulant, flocculant and leachate are fully mixed by stirring under acidic conditions, and the flocculants in the leachate after coagulation are settled by gravity to achieve solid-liquid separation. The generated sludge is dehydrated and dried, and the dried sludge is incinerated. The coagulant is ferric chloride; the flocculant is anionic polyacrylamide.

[0027] Step S3: Thiosulfate-enhanced persulfate advanced oxidation: adding an oxidant to the leachate to generate sulfate free radicals, destroying the structure of organic matter and effectively degrading refractory organic matter.

[0028] Using the sodium persulfate oxidation method, the pH is adjusted to neutral, and organic matter: sodium persulfate: thiosulfate ion is added in a mass ratio of 1:18:0.18. The iron ions introduced in step S2 are converted into ferrous ions by sodium thiosulfate, which activates the sodium persulfate oxidation. The oxidant and the leachate are fully mixed by heating and stirring in the reactor. The reaction time is generally 2 hours.

[0029] Step S4: Advanced treatment: Add sodium hypochlorite oxidant to the leachate to further remove the remaining ammonia nitrogen and organic matter to ensure that the pollutants in the leachate are basically removed.

[0030] Sodium hypochlorite is used to treat the remaining organic matter and ammonia nitrogen, and sodium ions and chloride ions are introduced to be recycled in the subsequent evaporation and crystallization process. After the reaction is completed, the pH value is adjusted to neutral or weak alkaline with an alkaline solution (such as sodium hydroxide) to facilitate subsequent treatment. The alkaline solution is sodium hydroxide.

[0031] Embodiment 1

[0032] The process experiment verification was carried out using actual leachate collected in October 2024. The leachate used in this experiment was high-salt industrial waste leachate with a pH value of 8.42, an organic matter concentration of 3314.12 mg / L, an ammonia nitrogen concentration of 1724.25 mg / L, and a conductivity of 182 mS / cm.

[0033] Step S1: Struvite precipitation: remove ammonia nitrogen and total phosphorus from the leachate. Adjust the pH of the leachate to a weak alkaline level (about 7-8), add an appropriate amount of magnesium chloride and struvite crystals treated at 200°C as a magnesium source and a seed crystal, respectively, stir and react for about 30 minutes, let it stand and precipitate, and recover the struvite crystals in the precipitate;

[0034] Step S2: Iron-based coagulation: adjust the pH of the leachate to weak acidity (about 5), add an appropriate amount of coagulant ferric chloride, coagulate at high speed for 5 minutes, add an appropriate amount of flocculant polyacrylamide, coagulate at medium speed for 5 minutes, and coagulate at low speed for 10 minutes to make the fine suspended matter condense into larger flocs, further remove ammonia nitrogen in the leachate, and adsorb the macromolecular organic matter in the leachate, let it settle, and achieve solid-liquid separation. The generated sludge is dehydrated and dried, and the dried sludge is incinerated to reduce the volume;

[0035] Step S3: Thiosulfate-enhanced persulfate advanced oxidation: adjust the pH of the coagulation supernatant to neutral (about 7), add organic matter: sodium persulfate: thiosulfate in a mass ratio of 1:18:0.18, heat and stir at 70°C to destroy the structure of the organic matter, improve its biodegradability, and effectively degrade the difficult-to-degrade organic matter. The reaction time is 2 hours;

[0036] Step S4: Advanced treatment: The pH of the advanced oxidation effluent is adjusted to acidic (about 4), and an appropriate amount of sodium hypochlorite is added for treatment. The reaction time is 60 minutes to further remove the remaining ammonia nitrogen and organic matter to ensure that the pollutants in the leachate are basically removed. After the reaction is completed, the pH value is adjusted to neutral or weakly alkaline with an alkaline solution (such as sodium hydroxide) to facilitate subsequent treatment.

[0037] After being treated by this process, the pH of the leachate is 8.5, the organic matter concentration is 120.97 mg / L, the ammonia nitrogen is 11.75 mg / L, and the conductivity is 155 mS / cm. At the same time, the various indicators of the leachate before and after the process are statistically analyzed, and the results are shown in the table below.

[0038] index Ammonia nitrogen (mg / L) COD(mg / L) Cu(mg / L) Fe(mg / L) Ni(mg / L) As(mg / L) Cost (Yuan) Raw water quality 1724.25 3314.12 7.47 131.11 23.27 109.51 500-600 Water quality after process treatment 11.75 120.97 0.19 1.25 0.24 0.35 235.88

[0039] At the same time, the effect diagram of removing the refractory organic matter in the leachate by the simultaneous denitrification and carbon removal method of the present invention is shown. Figure 2 A three-dimensional fluorescence spectrum showing the removal effect of difficult-to-degrade organic matter in leachate using the simultaneous denitrification and carbon removal method of the present invention, wherein a is high-salt leachate, b is struvite precipitation, c is iron-based coagulation, d is thiosulfate-enhanced persulfate advanced oxidation, and e is deep treatment. Figure 3 What is shown is the UV-visible spectrum of the removal effect of the simultaneous denitrification and carbon removal method of the present invention on the difficult-to-degrade organic matter in the leachate.

[0040] It can be seen from the three-dimensional fluorescence spectrum that the main components of the high-salt leachate are fulvic acid and humic acid. After being treated by the process of the present invention, fulvic acid and humic acid are completely removed, and only some biologically soluble byproducts remain; it can be seen from the UV-visible spectrum that the organic content in the treated high-salt leachate is greatly reduced, and the UV absorption peak before and after the treatment has a blue shift, indicating that the molecular conjugation effect in the treated water sample is reduced, indicating that the process of the present invention has a high removal efficiency for organic matter with a conjugated system of benzene ring structure, and the molecular weight and degree of polymerization of the organic matter after treatment are reduced. It shows that the process system of the present invention can effectively degrade the difficult-to-degrade organic matter in the industrial garbage leachate.

[0041] Embodiment 2

[0042] The process experiment verification was carried out using actual leachate collected in April 2024. The leachate used in this experiment was high-salt industrial waste leachate with a pH value of 8.83, an organic matter concentration of 2760.12 mg / L, an ammonia nitrogen concentration of 1754.25 mg / L, and a conductivity of 181.1 mS / cm.

[0043] Step S1: Struvite precipitation: remove ammonia nitrogen and total phosphorus from the leachate. Adjust the pH of the leachate to a weak alkaline level (about 7-8), add an appropriate amount of magnesium chloride and struvite crystals treated at 200°C as a magnesium source and a seed crystal, respectively, stir and react for about 30 minutes, let it stand and precipitate, and recover the struvite crystals in the precipitate;

[0044] Step S2: Iron-based coagulation: adjust the pH of the leachate to weak acidity (about 5), add an appropriate amount of coagulant ferric chloride, coagulate at high speed for 5 minutes, add an appropriate amount of flocculant polyacrylamide, coagulate at medium speed for 5 minutes, and coagulate at low speed for 10 minutes to make the fine suspended matter condense into larger flocs, further remove ammonia nitrogen in the leachate, and adsorb the macromolecular organic matter in the leachate, let it settle, and achieve solid-liquid separation. The generated sludge is dehydrated and dried, and the dried sludge is incinerated to reduce the volume;

[0045] Step S3: Thiosulfate-enhanced persulfate advanced oxidation: adjust the pH of the coagulation supernatant to neutral (about 7), add organic matter: sodium persulfate: thiosulfate in a mass ratio of 1:18:0.18, heat and stir at 70°C to destroy the structure of the organic matter, improve its biodegradability, and effectively degrade the difficult-to-degrade organic matter. The reaction time is 2 hours;

[0046] Step S4: Advanced treatment: The pH of the advanced oxidation effluent is adjusted to acidic (about 4), and an appropriate amount of sodium hypochlorite is added for treatment. The reaction time is 60 minutes to further remove the remaining ammonia nitrogen and organic matter to ensure that the pollutants in the leachate are basically removed. After the reaction is completed, the pH value is adjusted to neutral or weakly alkaline with an alkaline solution (such as sodium hydroxide) to facilitate subsequent treatment.

[0047] After being treated by this process, the pH of the leachate is 8.5, the organic matter concentration is 98.68 mg / L, the ammonia nitrogen is 8.17 mg / L, and the conductivity is 143.2 mS / cm. At the same time, the various indicators of the leachate before and after the process are statistically analyzed, and the results are shown in the table below.

[0048] index Ammonia nitrogen (mg / L) COD(mg / L) Cu(mg / L) Fe(mg / L) Ni(mg / L) As(mg / L) Raw water quality 1754.25 2760.12 17.47 51.11 42.27 89.51 Water quality after process treatment 8.17 98.68 1.21 0.74 0.59 0.11

[0049] Embodiment 3

[0050] The process experiment verification was carried out using actual leachate collected in December 2024. The leachate used in this experiment was high-salt industrial waste leachate with a pH value of 5.23, an organic matter concentration of 2445.37 mg / L, an ammonia nitrogen concentration of 1527.25 mg / L, and a conductivity of 172.8 mS / cm.

[0051] Step S1: Struvite precipitation: remove ammonia nitrogen and total phosphorus from the leachate. Adjust the pH of the leachate to a weak alkaline level (about 7-8), add an appropriate amount of magnesium chloride and struvite crystals treated at 200°C as a magnesium source and a seed crystal, respectively, stir and react for about 30 minutes, let it stand and precipitate, and recover the struvite crystals in the precipitate;

[0052] Step S2: Iron-based coagulation: adjust the pH of the leachate to weak acidity (about 5), add an appropriate amount of coagulant ferric chloride, coagulate at high speed for 5 minutes, add an appropriate amount of flocculant polyacrylamide, coagulate at medium speed for 5 minutes, and coagulate at low speed for 10 minutes to make the fine suspended matter condense into larger flocs, further remove ammonia nitrogen in the leachate, and remove the macromolecular organic matter in the leachate, let it settle to achieve solid-liquid separation. The generated sludge is dehydrated and dried, and the dried sludge is incinerated to reduce the volume;

[0053] Step S3: Thiosulfate-enhanced persulfate advanced oxidation: adjust the pH of the coagulation supernatant to neutral (about 7), add organic matter: sodium persulfate: thiosulfate in a mass ratio of 1:18:0.18, heat and stir at 70°C to destroy the structure of the organic matter, improve its biodegradability, and effectively degrade the difficult-to-degrade organic matter. The reaction time is 2 hours;

[0054] Step S4: Advanced treatment: The pH of the advanced oxidation effluent is adjusted to acidic (about 4), and an appropriate amount of sodium hypochlorite is added for treatment. The reaction time is 60 minutes to further remove the remaining ammonia nitrogen and organic matter to ensure that the pollutants in the leachate are basically removed. After the reaction is completed, the pH value is adjusted to neutral or weakly alkaline with an alkaline solution (such as sodium hydroxide) to facilitate subsequent treatment.

[0055] After being treated by this process, the pH of the leachate is 8.43, the organic matter concentration is 132.11 mg / L, the ammonia nitrogen is 5.26 mg / L, and the conductivity is 129.2 mS / cm. At the same time, the various indicators of the leachate before and after the process are statistically analyzed, and the results are shown in the table below.

[0056] index Ammonia nitrogen (mg / L) COD(mg / L) Cu(mg / L) Fe(mg / L) Ni(mg / L) As(mg / L) Raw water quality 1527.25 2445.37 11.37 84.17 29.55 64.89 Water quality after process treatment 5.26 132.11 0.81 1.34 0.67 0.29

[0057] Comparative example (compared with other processes)

[0058] The actual leachate collected in December 2024 was used for comparison with the existing process. The leachate used in this comparative experiment was high-salt industrial waste leachate with a pH value of 5.23, an organic matter concentration of 2445.37 mg / L, an ammonia nitrogen concentration of 1527.25 mg / L, and a conductivity of 172.8 mS / cm. The compared processes were the Fenton advanced oxidation process and the activated carbon adsorption-sodium hypochlorite oxidation process.

[0059] Fenton advanced oxidation process: adjust the leachate to 2-3, add ferrous salt and hydrogen peroxide in a certain proportion, stir in the reactor to make the ferrous salt and hydrogen peroxide fully mixed, the reaction time is 60 minutes, after the reaction is completed, adjust the pH to neutral or alkaline.

[0060] After treatment with the Fenton advanced oxidation process, the leachate pH was 7.5, the organic matter concentration was 189.14 mg / L, the ammonia nitrogen was 281.75 mg / L, and the conductivity was 161.4 mS / cm.

[0061] Activated carbon adsorption-sodium hypochlorite oxidation process: adjust the pH of the leachate to about 4, add powdered activated carbon in a certain proportion, aerate and stir in the reactor to allow the activated carbon to fully contact with the leachate, and the adsorption time is 120 minutes. After the adsorption is completed, stand and filter, add sodium hypochlorite in a certain proportion to the filtrate, and stir in the reactor to allow the sodium hypochlorite to fully react with the filtrate. The reaction time is 60 minutes.

[0062] After being treated by activated carbon adsorption-sodium hypochlorite oxidation process, the pH of the leachate was 3.24, the organic matter concentration was 414.34 mg / L, the ammonia nitrogen was 28.44 mg / L, and the conductivity was 157.9 mS / cm.

[0063] The final results of the three processes are compared in the table below.

[0064]

[0065] The advanced oxidation method used in the simultaneous denitrification and carbon removal method of the present invention is a sodium persulfate oxidation technology, and ferrous ions are introduced for co-activation at the same time as traditional thermal activation.

[0066] The simultaneous denitrification and carbon removal method of the present invention, in step S2, by adding an iron salt coagulant, while removing ammonia nitrogen and macromolecular organic matter in the leachate by coagulation and precipitation, introduces trivalent iron ions, and then by adding a reducing agent sodium thiosulfate in step 3, the trivalent iron ions are reduced to divalent ferrous ions, which play an activating role in the sodium persulfate advanced oxidation process in step 3.

[0067] The simultaneous denitrification and carbon removal method of the present invention includes the recovery and utilization of resources such as ammonia nitrogen and total phosphorus in the leachate.

[0068] The simultaneous denitrification and carbon removal method of the present invention is applied in the field of high-salt garbage leachate treatment.

Claims

1. A method for simultaneous denitrification and carbon removal of high-salt landfill leachate in industrial parks, characterized in that: The steps include: Step S1: struvite precipitation: adding magnesium salt to the leachate to remove ammonia nitrogen and total phosphorus in the leachate; Step S2: iron-based coagulation: adding a coagulant to the leachate to agglomerate fine particles into larger particles, and then using a flocculant to further enlarge and compact the particles to form large flocs that settle quickly, further removing ammonia nitrogen from the leachate, and adsorbing macromolecular organic matter in the leachate, thereby reducing the load of subsequent treatment procedures; Step S3: Thiosulfate-enhanced persulfate advanced oxidation: adding an oxidant to the leachate to generate sulfate free radicals, destroying the structure of organic matter and effectively degrading refractory organic matter; Step S4: Advanced treatment: Add sodium hypochlorite oxidant to the leachate to further remove the remaining ammonia nitrogen and organic matter to ensure that the pollutants in the leachate are basically removed.

2. The method for simultaneous denitrification and decarbonization of high-salt landfill leachate in industrial parks according to claim 1, characterized in that: In the struvite precipitation of step S1, the pH is adjusted to weak alkalinity before adding magnesium salt, and the ammonium magnesium phosphate crystals in the precipitation are recovered, thereby realizing the resource utilization of ammonia nitrogen and total phosphorus.

3. The method for simultaneous denitrification and decarbonization of high-salt landfill leachate in industrial parks according to claim 2, characterized in that: The above-mentioned magnesium salt is magnesium chloride.

4. The method for simultaneous denitrification and decarbonization of high-salt landfill leachate in industrial parks according to claim 1, characterized in that: In the iron-based coagulation of step S2, the coagulant, flocculant and leachate are fully mixed by stirring under acidic conditions, and the floccules in the leachate after coagulation are settled by gravity to achieve solid-liquid separation. The generated sludge is dehydrated and dried, and the dried sludge is incinerated.

5. The method for simultaneous denitrification and decarbonization of high-salt landfill leachate in industrial parks according to claim 4, characterized in that: The above-mentioned coagulant is ferric chloride; the flocculant is anionic polyacrylamide.

6. The method for simultaneous denitrification and decarbonization of high-salt landfill leachate in industrial parks according to claim 5, characterized in that: In the above-mentioned step S3 thiosulfate-enhanced persulfate advanced oxidation, a sodium persulfate oxidation method is used, the pH is adjusted to neutral, and organic matter: sodium persulfate: thiosulfate is added in a mass ratio of 1:18:0.

18. The iron ions introduced in step S2 are converted into ferrous ions by sodium thiosulfate, which activates the sodium persulfate oxidation, and the oxidant and the leachate are fully mixed by heating and stirring in the reactor. The reaction time is generally 2 hours.

7. The method for simultaneous denitrification and decarbonization of high-salt landfill leachate in industrial parks according to claim 1, characterized in that: In the above step S4 deep treatment, sodium hypochlorite is used to treat the remaining organic matter and ammonia nitrogen, and sodium ions and chloride ions are introduced to be recycled in the subsequent evaporation and crystallization process. After the reaction is completed, the pH value is adjusted to neutral or weak alkaline with an alkaline solution to facilitate subsequent treatment.

8. The method for simultaneous denitrification and decarbonization of high-salt landfill leachate in industrial parks according to claim 7, characterized in that: The above alkaline solution is sodium hydroxide.

Images