Method for simultaneously removing ammonia nitrogen and organic pollutants in landfill leachate

Abstract

The invention 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 technical problems that in the prior art, the removal effect of high-concentration ammonia nitrogen and organic pollutants in landfill leachate is poor, the follow-up biochemical treatment effect is limited, and a biochemical treatment system is prone to being subjected to huge impact are solved. The invention provides a method for simultaneously removing ammonia nitrogen and organic pollutants in landfill leachate. The method comprises the following steps: carrying out struvite crystallization reaction on the landfill leachate; carrying out solid-liquid separation after gravity settling to obtain upper liquid and crystals; the pH value of the upper liquid is adjusted to 2.0-3.0, Schwertmannite and H2O2 are added, the adding amount of the Schwertmannite is 2-20 g / L, V (H2O2) / m (Schwertmannite) is 0.25-5 mL / g, a photocatalytic reaction is conducted at the constant temperature, a photocatalytic reaction solution is obtained and filtered, and the photocatalyst is obtained. According to the method, ammonia nitrogen and organic pollutants are greatly removed in advance before the landfill leachate is subjected to biochemical treatment, so that the biodegradability of the landfill leachate is improved, the impact load of biochemical treatment is reduced, and the whole process flow is simplified.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a method for simultaneously removing ammonia nitrogen and organic pollutants in landfill leachate. Background Art

[0002] In recent years, the amount of domestic waste in my country has increased dramatically. About 80% of the waste is finally disposed of through sanitary landfills. However, during the landfill process, due to the decomposition of organic pollutants in domestic waste, rainwater infiltration and its own water content, it is very easy to produce secondary pollutants such as leachate. The most obvious characteristics of leachate are high ammonia nitrogen, high organic pollutants, high chroma, and a large number of pathogenic microorganisms, which pose a great threat to the quality of soil, surface water and groundwater. Therefore, the safe and harmless treatment and disposal of leachate is particularly important. Although the traditional sewage biochemical treatment process is mature in technology, it is difficult for the biochemical system to withstand the impact of high ammonia nitrogen and high organic pollutant loads for a long time, and it is difficult for the effluent to meet the standards stably, and even cause the system to collapse. If the high concentration of ammonia nitrogen and organic pollutants in the leachate are largely removed in advance before entering the biochemical treatment system, the effluent can be guaranteed to meet the standards stably.

[0003] The Chinese invention patent application publication number is CN118388089A, and the application date is June 18, 2024. The invention name is "A fully quantitative leachate treatment process based on Fenton treatment". The disclosed treatment process includes: first, the landfill leachate is stripped of ammonia, and then pumped into the iron-carbon Fenton tank for Fenton reaction. After these two steps, part of the ammonia nitrogen and organic pollutants are removed, and then biochemical treatment is carried out by anaerobic baffle-biological contact-aerated biological method. The effluent from the biochemical treatment is subjected to Fenton reaction again to further remove organic pollutants, and then coagulants (PAC and PAM) are added for coagulation and precipitation. Finally, the landfill leachate after coagulation and precipitation is introduced into the electrolytic cell for treatment. Although this method can safely and harmlessly render the landfill leachate harmless, there are still some shortcomings that cannot be ignored. First, the pH of the leachate is lower than 10, and the efficiency of ammonia stripping is low. Secondly, this method involves two Fenton reactions, which produces a lot of iron sludge that is difficult to dispose of. Moreover, the effluent from the biochemical treatment still needs to undergo coagulation, sedimentation and electrolysis treatment. The process is complicated, debugging is difficult, the amount of chemical agents used is large, and the operation and maintenance costs are high. The effluent from the biochemical treatment under this method still requires Fenton reaction, coagulation, sedimentation and electrolysis to further remove ammonia nitrogen and organic pollutants. In the final analysis, the removal effect of ammonia stripping and Fenton reaction on ammonia nitrogen and organic pollutants is limited, which in turn limits the effect of biochemical treatment.

[0004] Therefore, finding a pretreatment method for efficiently removing high-concentration ammonia nitrogen and organic pollutants in landfill leachate is of great significance for treating landfill leachate. Summary of the invention

[0005] 1. Problems to be solved

[0006] In view of the technical problems that the prior art has poor removal effect of high-concentration ammonia nitrogen and organic pollutants in landfill leachate, which limits the effect of subsequent biochemical treatment and easily causes impact on the biochemical treatment system, the present application provides a method for simultaneously removing ammonia nitrogen and organic pollutants in landfill leachate, combining the struvite crystallization method and the photocatalytic oxidation method to remove ammonia nitrogen and organic pollutants in the landfill leachate, and preliminarily removing ammonia nitrogen and organic pollutants to a large extent before the landfill leachate enters the biochemical treatment, thereby improving its biodegradability, reducing the impact load on the biochemical treatment, simplifying the entire process flow, and getting rid of the intervention of deep treatment.

[0007] 2. Technical solution

[0008] In order to achieve the above purpose, the technical solution provided is:

[0009] The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate comprises the following steps:

[0010] Performing a struvite crystallization reaction on the landfill leachate to obtain landfill leachate containing crystals;

[0011] The landfill leachate containing the crystals is subjected to gravity sedimentation and solid-liquid separation to obtain upper liquid and crystals;

[0012] The pH value of the upper liquid is adjusted to 2.0-3.0, and Schroeder mineral and H2O2 are added, wherein the amount of the Schroeder mineral added is 2g / L-20g / L, and V(H2O2) / m(Schroeder mineral) is 0.25mL / g-5mL / g. A photocatalytic reaction is carried out at a constant temperature to obtain a photocatalytic reaction liquid, and the photocatalytic reaction liquid is filtered to obtain a liquid from which ammonia nitrogen and organic pollutants are removed.

[0013] Preferably, the amount of the Schroeder mineral added is 12 g / L to 16 g / L.

[0014] Preferably, the V(H2O2) / m(Schmidtite) is 1.0 mL / g to 2.5 mL / g.

[0015] Preferably, the gravity sedimentation time is 30 minutes.

[0016] Furthermore, in the struvite crystallization reaction, phosphate is first added, and after it is dissolved, a magnesium source is added; the phosphate is one or more of disodium hydrogen phosphate, sodium dihydrogen phosphate and / or sodium phosphate and hydrates thereof; the magnesium source is one or more of magnesium chloride, magnesium oxide and / or magnesium sulfate and hydrates thereof.

[0017] Furthermore, the phosphate is Na2HPO4·12H2O, and the magnesium source is MgCl2·6H2O.

[0018] Furthermore, the addition amount of the Na2HPO4·12H2O and MgCl2·6H2O is determined according to the nitrogen content in the landfill leachate; the molar ratio of nitrogen, phosphorus and magnesium is X:Y:Z, X=Y=1, 0 <Z≤1.25。

[0019] Preferably, X:Y:Z=1:1:1.

[0020] Furthermore, the struvite crystallization reaction is carried out in a shaking table, the rotation speed of the shaking table is 150r / min to 180r / min, and the time is 30min to 60min.

[0021] Preferably, the shaking table has a rotation speed of 180 r / min and a time of 30 min.

[0022] Furthermore, the light source used in the photocatalytic reaction is ultraviolet light, and the intensity of the ultraviolet light is 300W to 500W.

[0023] Preferably, the intensity of the ultraviolet light is 500W.

[0024] Furthermore, the constant temperature is 25°C to 35°C and the time is 2h to 3h.

[0025] Preferably, the constant temperature is 35°C.

[0026] Furthermore, the initial pH value of the landfill leachate is 7.5-11.0, the initial ammonia nitrogen concentration is 750mg / L-800mg / L, the initial COD concentration is 10000mg / L-12000mg / L, the initial TOC concentration is 400mg / L-500mg / L, and the chromaticity is 50 times.

[0027] Preferably, the initial pH of the landfill leachate is 9.0.

[0028] Preferably, the pH of the landfill leachate is adjusted using HCl solution and / or NaOH solution.

[0029] Furthermore, the initial pH value is adjusted to 7.5-11.0 using HCl solution and / or NaOH solution with a molar concentration of 1M.

[0030] Furthermore, in the filtering step, Schroeder mineral is recovered.

[0031] 3. Beneficial effects

[0032] Compared with the existing known technology, the technical solution provided by the present invention has the following beneficial effects:

[0033] The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate of the present invention can significantly recover ammonia nitrogen from landfill leachate through the struvite crystallization reaction. The generated struvite crystals are rich in nutrients such as N, P and trace element Mg, and can be used as high-quality raw materials for producing slow-release multi-element composite slow-release fertilizers, which can improve soil fertility and avoid waste of nitrogen resources. Organic pollutants in landfill leachate are degraded by photocatalytic oxidation reaction of Schreiberite and H2O2 mediated by ultraviolet light. Compared with the traditional Fenton reaction to remove organic pollutants, this method does not produce a large amount of iron hydroxide sludge, and the recovered Schreiberite can still participate in the reaction as a photocatalyst, reducing the cost of using reagents. After the leachate was treated with the combined struvite crystallization method and photocatalytic oxidation method, the ammonia nitrogen removal rate was 87.0%, the TOC removal rate was 83.2%, and the COD removal rate was 50.2%. The ammonia nitrogen and organic pollutants were greatly removed and the color was improved. The large molecular organic pollutants in the leachate were degraded into small molecular organic pollutants, which greatly reduced the burden of subsequent conventional biochemical treatment, simplified the existing process flow, and avoided costly deep treatment links. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Effect of initial pH on the removal of ammonia nitrogen from landfill leachate by struvite crystallization (a) and the quality of the generated precipitate (b) when the molar ratio of nitrogen, phosphorus and magnesium is 1:1:1;

[0035] Figure 2 The SEM images of the precipitates generated after treating the landfill leachate by the struvite crystallization method under different initial pH conditions when the molar ratio of nitrogen, phosphorus and magnesium is 1:1:1;

[0036] Figure 3 The effect of the amount of Schroeder mineral added on the photocatalytic degradation of chromaticity, TOC and COD in landfill leachate when V(H2O2) / m(Schroeder mineral)=1.5mL / g;

[0037] Figure 4 The effect of V(H2O2) / m(Schmidt mineral) on the photocatalytic degradation of chromaticity, TOC and COD in landfill leachate when the addition amount of Schmidt mineral is 12g / L;

[0038] Figure 5 It is the removal rate of ammonia nitrogen, COD and TOC of the original landfill leachate and the leachate diluted 1.5 times and 3 times after joint treatment;

[0039] Figure 6 SEM images of Schmidtite after different times of use (a: 1 time, b: 2 times, c: 3 times, d: 4 times);

[0040] Figure 7 The following are Fourier infrared spectra of Schmidtite after different times of use. DETAILED DESCRIPTION

[0041] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with embodiments.

[0042] Example 1

[0043] The method for efficiently removing ammonia nitrogen from landfill leachate of this embodiment comprises the following steps:

[0044] 50 mL of landfill leachate was measured and placed in a 100 mL conical flask. The initial pH of the landfill leachate was adjusted to 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5 and 11 respectively with 1 M HCl solution and 1 M NaOH solution. According to the molar ratio of nitrogen, phosphorus and magnesium being 1:1:1, Na2HPO4·12H2O was first added, and after it was completely dissolved, MgCl2·6H2O was added. The landfill leachate was placed in a shaking table at 180 r / min for struvite crystallization reaction for 30 min to obtain landfill leachate containing crystals.

[0045] The landfill leachate containing crystals is gravity-sedimented for 30 minutes to obtain upper liquid and bottom crystals. The upper liquid is decanted and the bottom crystals are dried in an oven at 45°C to obtain struvite crystals, i.e., precipitate.

[0046] In this embodiment, as the pH increases, Figure 1 As shown in the figure, the sediment mass first increases and then tends to be stable, and the ammonia nitrogen removal rate first increases and then decreases. The pH corresponding to the trend change point is 9.0. At this time, the sediment mass reaches more than 11g / L, and the ammonia nitrogen removal rate is 88.1%. Figure 2 From the SEM images, we can see that in the process of pH increasing from 7.5 to 9.0, the content of irregular prisms in the precipitate gradually decreases, and the morphology of the precipitate gradually approaches a rhombus with a hollow cross-section; on this basis, the pH value of the reaction system continues to increase, and the precipitate gradually becomes mainly prisms, and the surface smoothness decreases; when pH = 11.0, the surface of the precipitate is rough, mainly rhombuses composed of needle-shaped substances, while the struvite crystals are rhombuses with smooth surfaces, so the SEM image at pH = 9 is closest to the struvite crystal microstructure.

[0047] Example 2

[0048] The method for efficiently removing organic pollutants from landfill leachate of this embodiment comprises the following steps:

[0049] Measure 25 mL of landfill leachate into several 50 mL quartz reaction tubes and adjust the initial pH of the leachate to 2.5 with 1 M H2SO4 solution;

[0050] 0, 2, 4, 8, 12, 16, 20 g / L of Schroeder mineral were added respectively, and then H2O2 was added, and the amount of H2O2 added was added according to V(H2O2) / m(Schroeder mineral)=1.5 mL / g. After mixing, the mixture was placed in a photocatalytic reactor and reacted at a constant temperature of 25°C for 2.5 h under 500 W ultraviolet light to obtain a photocatalytic reaction solution;

[0051] The photocatalytic reaction liquid was filtered, and the chromaticity, TOC and COD removal rates of the filtrate were determined.

[0052] In this embodiment, when V(H2O2) / m(Schmidtite)=1.5mL / g, the heterogeneous Fenton reaction of Schmidtite combined with H2O2 has a certain photocatalytic degradation effect on the pollutants in the landfill leachate. Figure 2 As shown in the figure, with the increase of the loading amount of Schroeder mineral, the removal rates of chromaticity, TOC and COD of landfill leachate showed a gradual upward trend, and basically reached a stable state at 12 g / L, with removal rates of 88.9%, 70.4% and 37.2%, respectively.

[0053] Example 3

[0054] The method for efficiently removing organic pollutants from landfill leachate of this embodiment comprises the following steps:

[0055] Measure 25 mL of landfill leachate into several 50 mL quartz reaction tubes and adjust the initial pH of the leachate to 2.5 with 1 M H2SO4 solution;

[0056] First, 12 g / L of Schroeder mineral was added, and then H2O2 was added according to V(H2O2) / m(Schroeder mineral) of 0.25, 0.5, 1.0, 2.0, 3.0 and 5.0 mL / g, respectively. After mixing, the mixture was placed in a photocatalytic reactor and reacted at a constant temperature of 25°C for 2.5 h under 500 W ultraviolet light to obtain a photocatalytic reaction solution;

[0057] The photocatalytic reaction liquid was filtered, and the chromaticity, TOC and COD removal rates of the filtrate were determined.

[0058] In this example, when the amount of Schroeder mineral added was 12 g / L, the amount of H2O2 added had different degrees of influence on the chromaticity, TOC and COD removal rates of the landfill leachate. Figure 3As shown in the figure, when V(H2O2) / m(Schwitzner mineral) is less than 2.0, the removal rates of chromaticity, TOC and COD increase from 70.0%, 59.0% and 30.5% when V(H2O2) / m(Schwitzner mineral)=0.25 to 96.0%, 79.6% and 44.9% when V(H2O2) / m(Schwitzner mineral)=2, respectively; when V(H2O2) / m(Schwitzner mineral) is greater than 2.0, the changes in chromaticity and TOC removal rates are smaller. This is because when V(H2O2) / m(Schwitzner mineral) is too high, relatively speaking, Schwitzner mineral is in a supersaturated state, and the excess H2O2 will react with the ·OH produced in the early stage to prevent ·OH from further degrading the pollutants.

[0059] Example 4

[0060] The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate of this embodiment comprises the following steps:

[0061] S1. Take 50 mL of landfill leachate in a 100 mL conical flask, adjust the initial pH of the leachate to 9.0 with HCl and NaOH solutions, add Na2HPO4·12H2O according to the molar ratio of nitrogen, phosphorus and magnesium of 1:1:1, and add MgCl2·6H2O after it is completely dissolved, and put it in a shaking table at 180 r / min for struvite crystallization reaction for 30 minutes to obtain landfill leachate containing crystals;

[0062] S2, subjecting the landfill leachate containing crystals to gravity sedimentation for 30 minutes to obtain an upper liquid and a bottom crystal, decanting the upper liquid, and drying the bottom crystal in an oven at 45°C to obtain struvite crystals, i.e., precipitate;

[0063] S3, pour the upper liquid portion decanted from S2 into a 50mL quartz tube, adjust the pH to 2.5 with 1M H2SO4 solution, add Schroeder mineral and H2O2 in order according to the amount of Schroeder mineral added of 16g / L and V(H2O2) / m(Schroeder mineral)=2.0mL / g, and then place in a photocatalytic reactor for constant temperature reaction at 25°C for 3.5h under 500W ultraviolet light to obtain a photocatalytic reaction solution;

[0064] S4. Filter the photocatalytic reaction liquid, and the filtrate is the effluent from the pretreatment stage. Determine the removal rates of ammonia nitrogen, chromaticity, TOC, and COD in the filtrate.

[0065] Because the pH of the landfill leachate is 8.5, which is close to the optimal pH of 9.0 for the struvite crystallization method, and the photocatalytic oxidation method requires a lower pH (pH 2.0-3.0), the struvite crystallization method is used first in this application, and then the photocatalytic oxidation method is used, which avoids adjusting the pH back and forth and saves the cost of reagents.

[0066] In this embodiment, the chromaticity of the original landfill leachate was 3 times after the combined treatment of struvite crystallization method and photocatalytic oxidation method, the TP removal rate was 97.8%, and the effluent concentration was 0.002 mg / L, meeting the emission requirements of the "Pollution Control Standard for Municipal Waste Landfills" (GB16889-2008); the ammonia nitrogen removal rate was 87.0%, and the effluent concentration was 100.9 mg / L; the COD removal rate was 50.2%, and the effluent concentration was 5590 mg / L; the TOC removal rate was 83.2%, and the effluent concentration was 84.72 mg / L, and 11.5 g / L of struvite crystals were generated at the same time. The macromolecular organic pollutants in the leachate were degraded into small molecular organic pollutants. Before and after photocatalysis, the organic pollutants with molecular weight greater than 25,000Da decreased from 38.7% to 29.5%, the organic pollutants greater than 3,500Da and less than 25,000Da increased from 29.8% to 48.6%, and the organic pollutants less than 3,500Da decreased from 31.5% to 21.9%. Due to the reaction conditions of the photocatalytic oxidation method under strong acidity and ultraviolet light irradiation, no microbial community was detected in the effluent.

[0067] The recovered struvite can be used multiple times. After four times of reuse, the TOC removal rate of the landfill leachate after struvite crystallization treatment is still 40%. The morphology and structure of the recovered struvite have not changed significantly (such as Figure 6 , Figure 7 As shown), it still has efficient photocatalytic performance and can be reused, thereby saving treatment costs; the tail water can also be subjected to multiple photocatalytic treatments to further reduce the content of organic pollutants and obtain more ideal water quality.

[0068] Example 5

[0069] The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate in this embodiment is basically the same as that in Example 4, except that the landfill leachate is diluted 1.5 times.

[0070] In this embodiment, the landfill leachate diluted 1.5 times was treated by the struvite crystallization method and the photocatalytic oxidation method. Figure 5 As shown, the ammonia nitrogen removal rate is 84.1%, the COD removal rate is 56.0%, the TOC removal rate is 83.6%, and the chromaticity is 3 times.

[0071] Example 6

[0072] The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate in this embodiment is basically the same as that in Example 4, except that the landfill leachate is diluted 3.0 times.

[0073] In this embodiment, the landfill leachate diluted 3.0 times was treated by the struvite crystallization method and the photocatalytic oxidation method. Figure 5As shown, the ammonia nitrogen removal rate is 81.0%, the COD removal rate is 59.6%, the TOC removal rate is 84.9%, and the chromaticity is 2 times respectively.

[0074] The present application provides a method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate. First, ammonia nitrogen in landfill leachate is largely recovered through a struvite crystallization reaction. The generated struvite crystals are rich in nutrients such as N, P and trace elements Mg, which can be used as high-quality raw materials for producing slow-release multi-element composite slow-release fertilizers, which can improve soil fertility and avoid the waste of nitrogen resources. Then, the organic pollutants in the landfill leachate are degraded by a photocatalytic oxidation reaction of Schmidt mineral and H2O2 mediated by ultraviolet light. Compared with the removal of organic pollutants by the traditional Fenton reaction, this method does not produce a large amount of iron hydroxide mud, and the recovered Schmidt mineral can still participate in the reaction as a photocatalyst, reducing the cost of using the agent. After the landfill leachate is treated by the struvite crystallization method and the photocatalytic oxidation method, ammonia nitrogen and organic pollutants are greatly removed and the chromaticity is improved. The macromolecular organic pollutants in the leachate are degraded into small molecular organic pollutants, which greatly reduces the burden of subsequent conventional biochemical treatment, simplifies the existing process flow, and avoids the expensive deep treatment link.

[0075] The above-mentioned embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person skilled in the art, several modifications, improvements and substitutions can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate, characterized in that: The following steps are involved: Performing a struvite crystallization reaction on the landfill leachate to obtain landfill leachate containing crystals; The landfill leachate containing the crystals is subjected to gravity sedimentation and solid-liquid separation to obtain an upper liquid and crystals; The pH value of the upper liquid is adjusted to 2.0-3.0, and Schroeder mineral and H2O2 are added, wherein the amount of the Schroeder mineral added is 2g / L-20g / L, and V(H2O2) / m(Schroeder mineral) is 0.25mL / g-5mL / g. A photocatalytic reaction is carried out at a constant temperature to obtain a photocatalytic reaction liquid, and the photocatalytic reaction liquid is filtered to obtain a liquid from which ammonia nitrogen and organic pollutants are removed.

2. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to claim 1, characterized in that: In the struvite crystallization reaction, phosphate is first added, and after it is dissolved, a magnesium source is added; the phosphate is one or more of disodium hydrogen phosphate, sodium dihydrogen phosphate and / or sodium phosphate and hydrates thereof; the magnesium source is one or more of magnesium chloride, magnesium oxide and / or magnesium sulfate and hydrates thereof.

3. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to claim 2, characterized in that: The phosphate is Na2HPO4·12H2O, and the magnesium source is MgCl2·6H2O.

4. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to claim 3, characterized in that: The amount of Na2HPO4·12H2O and MgCl2·6H2O added is determined according to the nitrogen content in the landfill leachate; the molar ratio of nitrogen, phosphorus and magnesium is X:Y:Z, X=Y=1, 0 <Z≤1.25。 5. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to claim 4, characterized in that: The struvite crystallization reaction is carried out in a shaking table with a rotation speed of 150 r / min to 200 r / min and a time of 30 min to 60 min.

6. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to claim 1, characterized in that: The light source used in the photocatalytic reaction is ultraviolet light, and the intensity of the ultraviolet light is 300W to 500W.

7. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to claim 1, characterized in that: The constant temperature is 25°C to 35°C and the constant temperature time is 2h to 3h.

8. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to claims 1-7, characterized in that: The initial pH value of the landfill leachate is 7.5-11.0, the initial ammonia nitrogen concentration is 750mg / L-800mg / L, the initial COD concentration is 10000mg / L-12000mg / L, the initial TOC concentration is 400mg / L-500mg / L, and the chromaticity is 50 times.

9. The method for simultaneously removing ammonia nitrogen and organic pollutants from landfill leachate according to claim 8, characterized in that: The initial pH value is adjusted to 7.5-11.0 using HCl solution and / or NaOH solution with a molar concentration of 1M.

10. The method of simultaneously removing ammonia nitrogen and organic pollutants in the waste leachate as claimed in claim 8, characterized in that: In the filtering step, the Schroeder mineral is recovered.

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