A full-scale treatment process for landfill leachate

Abstract

The application discloses a kind of garbage leachate full-quantization processing technology, it is related to leachate processing technical field.The application is with carboxymethyl starch sodium as skeleton, graft acrylamide and the modified vinylpyridine of 5-chloromethyl salicylal quaternary ammonium salt, after secondary crosslinking again with aminothiourea graft modification preparation.It has high salt tolerance and heavy metal chelating ability, can efficiently adsorb heavy metals in high salt environment, and after adsorption, can be through pyridine base enrichment and nitration inhibition synergistic effect to strengthen nitrate removal, realize the synchronous treatment of organic matter, ammonia nitrogen, heavy metal and nitrate in leachate, simple process and environment-friendly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of leachate treatment, in particular to a full-quantitative treatment process for landfill leachate. BACKGROUND

[0002] At present, the leachate of landfill has the following characteristics: 1. Complex pollutant composition and large water quality fluctuation. Because of the complex composition of garbage, the pollutant composition of leachate is complex. The pollution components of leachate include organic matter, inorganic ions and nutrients. Among them, the main ones are ammonia nitrogen and various dissolved cations, heavy metals, phenols, soluble fatty acids and other organic pollutants. 2. High concentration of organic matter. The BOD and COD concentrations in landfill leachate can reach tens of thousands of mg / L, but they will gradually decrease with the increase of landfill time. Even so, they still reach several thousand mg / L, which is still relatively high compared with other wastewater. And the leachate contains a large amount of humic acid. 3. High ammonia nitrogen concentration. The ammonia nitrogen concentration increases with the increase of landfill time. The nitrogen in the leachate exists mainly in the form of ammonia nitrogen. The ammonia nitrogen concentration in landfill leachate increases with the increase of landfill time. 4. High concentration of heavy metal ions and salt content. When domestic garbage is filled alone, the content of heavy metals is relatively low. However, when mixed with industrial waste or sludge, the content of heavy metals and salt will be very high. The use of biochemical treatment will cause inhibition and toxic effects on biochemistry due to the high salt content. It is difficult to start, the operation is unstable, and even cannot run.

[0003] Therefore, the present application uses modified denitrification resin for treatment, and designs a process flow matched therewith. The modified denitrification resin has high salt tolerance, can chelate and adsorb heavy metal ions, and can also promote the removal of nitrate after chelating and adsorbing heavy metal ions, so as to enhance the denitrification treatment capacity. SUMMARY

[0004] The purpose of the present application is to provide a full-quantitative treatment process for landfill leachate to solve the problems in the prior art.

[0005] In order to solve the above technical problems, the present application provides the following technical scheme:

[0006] A full-quantitative treatment process for landfill leachate, comprising the following steps:

[0007] Pretreatment of the adjusting tank: the leachate is introduced into the adjusting tank, the water quality and quantity are adjusted by the water inlet pump, and the water level is monitored in real time by the liquid level meter;

[0008] Combined treatment of the biochemical tank: after pretreatment in the adjusting tank, the leachate enters the biochemical tank, the organic matter is degraded by the aeration blower, and biological denitrification and phosphorus removal are realized by the reflux system;

[0009] SMT-DT efficient catalytic oxidation advanced treatment: the effluent from the biochemical tank is treated by the SMT-DT efficient catalytic oxidation module, a magnetic field is generated by an external electric field, and two-phase catalytic oxidation is used;

[0010] Integrated special bacteria MBR system: the effluent treated by the SMT-DT catalytic oxidation is separated by the MBR membrane system, the water quality is improved by the water pump, the membrane assembly is maintained regularly by the backwash pump, and the integrated efficient bacteria biological denitrification module is connected, the halophilic denitrifying bacteria is added, the denitrification is promoted, and after the denitrification, the wastewater enters the secondary MBR membrane, and the ammonia nitrogen and the carbon source are further removed by controlling the residence time;

[0011] Denitrification resin treatment: the final effluent is treated by the denitrification resin tank, the modified denitrification resin is filled, the residual nitrate is adsorbed, and the discharge standard is achieved;

[0012] The modified denitrification resin comprises: carboxymethyl starch sodium, acrylamide and modified vinylpyridine.

[0013] The modified denitrification resin is prepared by grafting acrylamide and modified vinylpyridine onto carboxymethyl starch sodium by reverse suspension polymerization, and then grafting modification by aminothiourea after secondary cross-linking and solidification.

[0014] As an optimization, the modified vinylpyridine is prepared by quaternizing pyridyl with 5-chloromethyl salicylaldehyde.

[0015] As an optimization, the mass ratio of the carboxymethyl starch sodium, the acrylamide and the modified vinylpyridine is 3:12-15:6-8.

[0016] As an optimization, the modified denitrification resin comprises the following preparation steps:

[0017] S1, carboxymethyl starch sodium, acrylamide and modified vinyl pyridine are weighed according to the mass ratio of 3:12~15:6~8; the carboxymethyl starch sodium is added to the deionized water with 40~45 times the mass of the carboxymethyl starch sodium, after stirring and dissolving, acrylamide and grafted vinyl pyridine are added, then 0.08~0.1 times the mass of the carboxymethyl starch sodium of potassium persulfate and 0.004~0.006 times the mass of the carboxymethyl starch sodium of N, N-methylene bisacrylamide are added, and stirred uniformly to prepare a polymerization solution; then the polymerization solution is added to the cyclohexane solution with 0.5~0.7 times the volume of the polymerization solution, and 0.2~0.3 times the mass of the carboxymethyl starch sodium of epichlorohydrin is added, after stirring for 30~40 min at a temperature of 30~40℃, the temperature is raised to 60~70℃, and stirring is carried out for 2~2.5 h to prepare a mixed mother liquor, then the mixed mother liquor is added to the coagulation solution with 10~15 times the volume of the mixed mother liquor, and is solidified into a ball, and after standing for 30~40 min, filtration and washing 3~5 times with deionized water, a preliminary cross-linked microsphere is prepared, and then secondary cross-linking is carried out to prepare a cross-linked microsphere;

[0018] S2, the thiosemicarbazide is added to the anhydrous ethanol with 12~15 times the mass of the thiosemicarbazide, and stirred uniformly, then the cross-linked microsphere with 2~5 times the mass of the thiosemicarbazide is added, and then the acetic acid with 0.2~0.3 times the mass of the thiosemicarbazide is added, after stirring and refluxing for 6~7 h, filtration and Soxhlet extractor extraction with ethanol for 24~26 h, and vacuum drying, a modified denitrification resin is prepared.

[0019] As an optimization, the coagulation solution is prepared by mixing and stirring anhydrous sodium sulfate, sodium hydroxide, deionized water and anhydrous ethanol according to the mass ratio of 1:1.2~1.4:22~25:0.15~0.2.

[0020] As an optimization, the cyclohexane solution is prepared by mixing and stirring cyclohexane and docetaxel according to the mass ratio of 75~80:1.

[0021] As an optimization, the secondary cross-linking includes the following preparation steps: the preliminary cross-linked microsphere is extracted with ethanol by a Soxhlet extractor for 3~4 h, then washed with ethanol and deionized water for 3~5 times respectively, dehydrated, and then placed in the sodium hydroxide aqueous solution with pH=13 and 10~12 times the mass of the preliminary cross-linked microsphere, then the epichlorohydrin with 0.1~0.2 times the mass of the preliminary cross-linked microsphere is added, and stirring is carried out at a temperature of 60~70℃ for 2~2.5 h, and then the cross-linked microsphere is prepared by washing to neutral with deionized water and dehydrating.

[0022] As optimization, the modified vinylpyridine comprises the following preparation steps: adding vinylpyridine into acetonitrile solution with 10-12 times of the mass of the vinylpyridine, adding 5-chloromethyl salicylaldehyde with 1.3-1.5 times of the mass of the vinylpyridine dropwise after stirring, stirring uniformly, reacting for 24-26 hours at a temperature of 65-75 DEG C, and preparing grafted vinylpyridine by rotary evaporation and recrystallization with acetonitrile after the reaction.

[0023] As optimization, the acetonitrile solution is prepared by mixing acetonitrile and ethyl acetate in a volume ratio of 1:3-3.5 and stirring uniformly.

[0024] Compared with the prior art, the application has the following beneficial effects:

[0025] The technical scheme of the application adopts sodium carboxymethyl starch, acrylamide and modified vinylpyridine quaternized by 5-chloromethyl salicylaldehyde as raw materials, and a modified denitrification resin is prepared by grafting through a reverse suspension polymerization method and secondary crosslinking and amino thiourea modification, and the modified denitrification resin can maintain structural stability in a high-salt environment due to the synergistic effect of the polysaccharide skeleton and the crosslinking network, and the salt tolerance can adapt to the characteristics of high salt content in landfill leachate, thereby avoiding the operation instability caused by high salt inhibition in traditional biochemical treatment, and providing a reliable material basis for full-scale treatment of leachate.

[0026] The pyridyl functional groups in the modified denitrification resin and the thiourea groups grafted by amino thiourea form multiple chelating sites, exhibit strong adsorption capacity for heavy metal ions in the landfill leachate, efficiently capture the heavy metals through coordination, reduce the toxic effect of the heavy metals on microorganisms, and the secondary crosslinking structure of the resin enhances the mechanical strength, so that the resin is not easily broken during the heavy metal adsorption process, and long-term stable operation is realized.

[0027] Especially important is that the synergistic effect of the pyridyl functional groups and the thiourea groups on the surface of the resin after chelating and adsorbing heavy metal ions can further promote the removal of nitrate - the enrichment of pyridyl groups on nitrate and the change of the microenvironment after adsorption of heavy metals improve the contact efficiency of nitrate and active sites of the resin, and the nitration inhibition function of amino thiourea blocks the conversion path of ammonia nitrogen to nitrate, forming a synergistic denitrification mechanism of "heavy metal adsorption-nitrate removal", and significantly enhancing the denitrification treatment capacity of the landfill leachate. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A process flow chart of full-scale treatment of landfill leachate is shown. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0030] Embodiment 1

[0031] S1, the vinylpyridine is added into acetonitrile solution with 10 times of the mass of the vinylpyridine, stirred uniformly, then 5-chloromethyl salicylaldehyde with 1.3 times of the mass of the vinylpyridine is added dropwise, stirred uniformly, and reacted for 24 h at 65℃. After the reaction, the product is obtained by rotary evaporation and recrystallization from acetonitrile. The acetonitrile solution is prepared by mixing acetonitrile and ethyl acetate in a volume ratio of 1:3 and stirring uniformly.

[0032] S2, carboxymethyl starch sodium, acrylamide and modified vinylpyridine are weighed according to a mass ratio of 3:12:6. The carboxymethyl starch sodium is added into deionized water with 40 times of the mass of the carboxymethyl starch sodium, stirred and dissolved, then the acrylamide and the grafted ethylene pyridine are added, followed by adding 0.08 times of the mass of the carboxymethyl starch sodium of potassium persulfate and 0.004 times of the mass of the carboxymethyl starch sodium of N,N-methylene bisacrylamide, and stirring uniformly to prepare a polymerization solution. Then the polymerization solution is added dropwise into a cyclohexane solution with 0.5 times of the volume of the polymerization solution, and 0.2 times of the mass of the carboxymethyl starch sodium of epichlorohydrin is added. After stirring for 30 min at 30℃, the temperature is raised to 60℃, and the stirring is continued for 2 h to obtain a mixed mother liquor. Then the mixed mother liquor is added into a coagulation solution with 10 times of the volume of the mixed mother liquor, and the product is coagulated into a ball, and is left to stand for 30 min. After filtration and washing with deionized water for 3 times, the preliminary cross-linked microspheres are obtained. The coagulation solution is prepared by mixing anhydrous sodium sulfate, sodium hydroxide, deionized water and anhydrous ethanol according to a mass ratio of 1:1.2:22:0.15 and stirring uniformly. The cyclohexane solution is prepared by mixing cyclohexane and docusate according to a mass ratio of 75:1 and stirring uniformly.

[0033] S3, the preliminary cross-linked microspheres are extracted with ethanol by a Soxhlet extractor for 3 h, then washed with ethanol and deionized water for 3 times respectively, dehydrated, and then placed in a sodium hydroxide aqueous solution with a pH of 13 and 10 times of the mass of the preliminary cross-linked microspheres. Then 0.1 times of the mass of the preliminary cross-linked microspheres of epichlorohydrin is added, and the stirring is continued for 2 h at 60℃. After being taken out, washed with deionized water until neutral, and dehydrated, the cross-linked microspheres are obtained.

[0034] S4, add aminothiourea to anhydrous ethanol 12 times the mass of aminothiourea, stir evenly, then add cross-linked microspheres 2 times the mass of aminothiourea, then add acetic acid 0.2 times the mass of aminothiourea, then stir and reflux for 6 hours, filter, then use a Soxhlet extractor to extract with ethanol for 24 hours, then vacuum dry to obtain the modified denitrification resin.

[0035] Example 2:

[0036] S1, add vinylpyridine to acetonitrile solution 11 times the mass of vinylpyridine, stir evenly, then add 5-chloromethyl salicylaldehyde 1.4 times the mass of vinylpyridine, stir evenly, react at 70°C for 25 hours, then rotary evaporate, then recrystallize with acetonitrile to obtain grafted vinylpyridine; the acetonitrile solution is prepared by mixing acetonitrile and ethyl acetate in a volume ratio of 1:3.25 and stirring evenly.

[0037] S2, weigh carboxymethyl starch sodium, acrylamide and modified vinylpyridine according to a mass ratio of 3:13.5:7; add carboxymethyl starch sodium to deionized water 42.5 times the mass of carboxymethyl starch sodium, stir and dissolve, then add acrylamide and grafted vinylpyridine, then add potassium persulfate 0.09 times the mass of carboxymethyl starch sodium and N,N-methylenebisacrylamide 0.005 times the mass of carboxymethyl starch sodium, stir evenly to prepare a polymerization solution; then add the polymerization solution to cyclohexane solution 0.6 times the volume of the polymerization solution, and add epichlorohydrin 0.25 times the mass of carboxymethyl starch sodium, stir at 35°C for 35 minutes, then heat to 65°C, stir and react for 2.25 hours to obtain a mixed mother liquor, then add the mixed mother liquor to coagulation solution 12.5 times the volume of the mixed mother liquor, coagulate into balls, stand for 35 minutes, filter and wash with deionized water 4 times to obtain preliminary cross-linked microspheres; the coagulation solution is prepared by mixing anhydrous sodium sulfate, sodium hydroxide, deionized water and anhydrous ethanol in a mass ratio of 1:1.3:23.5:0.175 and stirring evenly; the cyclohexane solution is prepared by mixing cyclohexane and docetaxel in a mass ratio of 77.5:1 and stirring evenly.

[0038] S3, use a Soxhlet extractor to extract the preliminary cross-linked microspheres with ethanol for 3.5 hours, then wash with ethanol and deionized water 4 times respectively, then dehydrate, then place in sodium hydroxide aqueous solution 11 times the mass of the preliminary cross-linked microspheres, with pH=13, then add epichlorohydrin 0.15 times the mass of the preliminary cross-linked microspheres, stir and react at 65°C for 2.25 hours, then take out, wash with deionized water until neutral, then dehydrate to obtain cross-linked microspheres.

[0039] S4, add aminothiourea to anhydrous ethanol with 13.5 times the mass of aminothiourea, stir until uniform, then add cross-linked microspheres with 3.5 times the mass of aminothiourea, then add acetic acid with 0.25 times the mass of aminothiourea, then stir and reflux for 6.5 hours, filter, then extract with ethanol using a Soxhlet extractor for 25 hours, then dry in a vacuum to obtain the modified denitrification resin.

[0040] Example 3:

[0041] S1, add vinylpyridine to acetonitrile solution with 12 times the mass of vinylpyridine, stir until uniform, then add 5-chloromethyl salicylaldehyde with 1.5 times the mass of vinylpyridine, stir until uniform, then react at 75°C for 26 hours, then rotary evaporate, then recrystallize from acetonitrile to obtain grafted vinylpyridine; the acetonitrile solution is prepared by mixing acetonitrile and ethyl acetate in a volume ratio of 1:3.5 and stirring until uniform.

[0042] S2, weigh carboxymethyl starch sodium, acrylamide, and modified vinylpyridine in a mass ratio of 3:15:8; add carboxymethyl starch sodium to deionized water with 45 times the mass of carboxymethyl starch sodium, stir until dissolved, then add acrylamide and grafted vinylpyridine, then add potassium persulfate with 0.1 times the mass of carboxymethyl starch sodium and N,N-methylenebisacrylamide with 0.006 times the mass of carboxymethyl starch sodium, stir until uniform to prepare a polymerization solution; then add the polymerization solution to cyclohexane solution with 0.7 times the volume of the polymerization solution, and add epichlorohydrin with 0.3 times the mass of carboxymethyl starch sodium, stir at 40°C for 40 minutes, then heat to 70°C and stir for 2.5 hours to obtain a mixed mother liquor, then add the mixed mother liquor to coagulation solution with 15 times the volume of the mixed mother liquor, coagulate into spheres, stand for 40 minutes, filter, and wash 5 times with deionized water to obtain preliminary cross-linked microspheres; the coagulation solution is prepared by mixing anhydrous sodium sulfate, sodium hydroxide, deionized water, and anhydrous ethanol in a mass ratio of 1:1.4:25:0.2 and stirring until uniform; the cyclohexane solution is prepared by mixing cyclohexane and docusate in a mass ratio of 80:1 and stirring until uniform.

[0043] S3, extract the preliminary cross-linked microspheres with ethanol using a Soxhlet extractor for 4 hours, then wash 5 times with ethanol and deionized water respectively, then dehydrate, then place in sodium hydroxide aqueous solution with a pH of 13 and 12 times the mass of the preliminary cross-linked microspheres, then add epichlorohydrin with 0.2 times the mass of the preliminary cross-linked microspheres, stir at 70°C for 2.5 hours, then remove, wash with deionized water until neutral, then dehydrate to obtain cross-linked microspheres.

[0044] S4, the thiosemicarbazide is added to 15 times the mass of the thiosemicarbazide of anhydrous ethanol, stirred uniformly, then 5 times the mass of the thiosemicarbazide of crosslinked microspheres is added, then 0.3 times the mass of the thiosemicarbazide of acetic acid is added, then stirred and refluxed for 7 hours, filtered, then extracted with ethanol by a Soxhlet extractor for 26 hours, and vacuum dried to obtain the modified denitrification resin.

[0045] Example 4:

[0046] The difference from Example 2 is only that the "modified vinyl pyridine" in step S2 is modified to "vinyl pyridine", and step S4 is not performed;

[0047] Example 5:

[0048] The difference from Example 2 is only that step S4 is not performed;

[0049] The materials prepared in the above Examples 1-5 are subjected to the following performance tests, and the test methods are as follows, and the test results are shown in Table 1 below:

[0050] Prepare multiple groups of 50 mg of the materials prepared in Examples 1-5, and add them to 50 mL of a nitrate (56.4 mg / L) solution, 50 mL of a mixed salt (nitrate (56.4 mg / L) + Cl -1 (250 mg / L) solution, and 50 mL of a mixed salt (nitrate (56.4 mg / L) + Cl -1 (250 mg / L) + metal ion (50 mg / L) solution, continue to shake after adding, and extract the supernatant after 60 minutes, and measure the nitrate adsorption amount by using an electrochemical workstation;

[0051] Table 1

[0052] ;

[0053] As shown by the data in Table 1, the denitrification resins prepared in Examples 1-3 have good salt resistance and denitrification treatment capacity.

[0054] Among them, the indicators of Example 4 also perform well, and the main reason for the performance decline is that the 5-chloromethyl salicylaldehyde is not modified, resulting in poor hydrophilic ability. In Example 5, the thiosemicarbazide is not modified, and the nitration inhibition capacity is lacking. Although the denitrification capacity of each group of experiments is significantly improved after the addition of metal ions, the data of Example 4 and Example 5 is obviously lower than that of the denitrification resins in Examples 1-3, which is because the metal ions themselves have a certain degree of denitrification capacity. However, due to the lack of thiosemicarbazide grafting in Example 4 and Example 5, the heavy metal adsorption capacity is not good, and the synergistic effect is not good, and the nitration inhibition effect is not good.

[0055] Example 6

[0056] There are three kinds of process routes for current full-scale treatment: 1, pretreatment + biochemical treatment + advanced oxidation (Fenton and other chemical oxidation) + biochemical treatment (security section); 2, pretreatment + membrane concentration + MVR evaporation + mother liquor solidification; 3, pretreatment + biochemical treatment + SMT-DT high-efficiency catalytic oxidation + biochemical treatment (security section). The advantages and disadvantages of the three kinds of treatment ideas are shown in Table 2:

[0057] Project Pretreatment + biochemical treatment + advanced oxidation Pretreatment + membrane concentration + MVR evaporation + mother liquor solidification Pretreatment + biochemical treatment + SMT-DT high-efficiency catalytic oxidation + biochemical treatment (security section) Process introduction First, a part of COD, ammonia nitrogen, total nitrogen, etc. is degraded by biochemical treatment. At the end of the treatment, catalytic oxidation process is used to produce hydroxyl radicals to forcibly oxidize organic matter and ammonia nitrogen in the leachate, and then the biochemical system is used for further treatment to realize the discharge of leachate meeting the standard Through pretreatment to remove hardness, the suspended solids and hardness of the leachate meet the requirements of the membrane system. Then the concentrated liquid is treated by evaporation to realize the discharge of the effluent meeting the standard First, a part of COD, ammonia nitrogen, total nitrogen, etc. is degraded by biochemical treatment. At the end of the treatment, electro-catalytic oxidation is used to produce a large number of free radicals with strong oxidizing properties to degrade organic pollutants, and ammonia nitrogen and total nitrogen can be removed. Then the biochemical system is used for further treatment to realize the discharge of leachate meeting the standard Investment cost High High High Operating cost High High High Effluent quality Generally, there is a risk of exceeding the standard of total nitrogen Excellent Excellent System stability The whole process uses biological and chemical methods, which has very low tolerance to water quality fluctuations. The dosage and other operating parameters are dynamically changed, and the system stability is poor, with the risk of exceeding the standard of total nitrogen The whole process is a physical reaction, and the system stability is very strong. At the same time, the removal of leachate salt is realized The whole process uses biological and electrical methods, without the need to add dangerous chemicals such as acid and oxidants. The oxidation section can be automatically controlled, and the system stability is good Dangerous chemical requirements Sulfur (salt) acid, hydrogen peroxide Sulfur (salt) acid None Hazardous waste generation A large amount of sludge containing iron salt, whether it belongs to hazardous waste needs to be detected Evaporated salt or solidified mother liquor, whether it belongs to hazardous waste needs to be detected None

[0058] The present application combines the above three kinds of full-scale processes, and optimizes the design, and the optimized process flow is as follows: pretreatment + biochemical treatment + SMT-DT high-efficiency catalytic oxidation + integrated special bacteria MBR system (security section) + denitrification resin treatment (security section); The design combines the advantages of the above three kinds of full-scale processes, and introduces two security sections as subsequent guarantee, and improves the system redundancy degree;

[0059] The full-scale treatment process of landfill leachate is specifically referred to Figure 1 :

[0060] Pretreatment of conditioning tank: introduce the leachate into the conditioning tank, adjust the water quality and quantity by the water inlet pump, and monitor the water level in real time by the liquid level meter;

[0061] Combined treatment of biochemical tank: after pretreatment in the conditioning tank, enter the biochemical tank, and degrade organic matter by aeration fan, and realize biological denitrification and phosphorus removal by cooperating with the reflux system;

[0062] SMT-DT high-efficiency catalytic oxidation deep treatment: the effluent from the biochemical tank is treated by SMT-DT high-efficiency catalytic oxidation module, which utilizes the magnetic field generated by the external electric field for double-phase catalytic oxidation; wherein the SMT-DT high-efficiency catalytic oxidation deep treatment adopts the SME-DT high-efficiency catalytic oxidation wastewater treatment device introduced in CN202510398742.2, and when in use, the water flow passes through the gap between the first disc shaft and the positive electrode cylinder, the gap between the second disc and the negative electrode cylinder, and the surface of the first disc and the second disc in sequence, and the water flow and the surfaces of the first disc and the second disc are in full contact. At the same time, when the electromagnet slides, the magnetic field position can be changed, so that the magnetic induction lines cut the water flow, which is beneficial to improve the efficiency of catalytic oxidation and optimize the effluent water quality. Moreover, the electromagnet can slide on the outer wall of the fixed pipe, and the electromagnet can generate a magnetic field. Under the synergistic action of the magnetic field and the electric field, the water flow is subjected to double-phase catalytic oxidation, thereby improving the treatment efficiency;

[0063] Integrated special effect bacteria MBR system: the effluent treated by SMT-DT catalytic oxidation is separated by MBR membrane system, the water quality is improved by water pump, the membrane assembly is maintained regularly by backwashing pump, and an integrated high-efficiency bacteria biological denitrification module is connected, halophilic denitrifying bacteria is added, denitrification is promoted, and after denitrification, the wastewater enters the secondary MBR membrane, and by controlling the residence time, ammonia nitrogen and carbon source are further removed;

[0064] Denitrification resin treatment: the final effluent passes through a denitrification resin tank, is filled with modified denitrification resin, and adsorbs residual nitrate, so that discharge standards are achieved.

[0065] It will be obvious to those skilled in the art that the application is not limited to the details of the above-described exemplary embodiments, but that the application can be implemented in other concrete forms without departing from the spirit or essential characteristics of the application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the application being defined by the appended claims rather than the above description, and it is intended that all changes that come within the meaning and range of equivalency of the claims are embraced therein. Any reference signs in the claims should not be construed as limiting the claims concerned.

Claims

1. A fully quantitative treatment process for landfill leachate, characterized in that: The following steps are involved: Pretreatment in the regulating tank: leachate is introduced into the regulating tank, water quality and quantity are adjusted by the water inlet pump, and the water level is monitored in real time using a liquid level meter; Combined treatment in biochemical pool: After pre-treatment in the regulating pool, the water enters the biochemical pool, where it is treated and degraded by an aeration fan, and combined with a reflux system to achieve biological nitrogen and phosphorus removal; High-efficiency catalytic oxidation deep treatment: The effluent from the biochemical pool passes through a high-efficiency catalytic oxidation module, which uses an external electric field to generate a magnetic field for two-phase catalytic oxidation; Integrated special-effect bacteria MBR system: The effluent from catalytic oxidation treatment is separated by the MBR membrane system. The water production pump improves the water quality. The backwash pump regularly maintains the membrane components. It is connected to the integrated high-efficiency bacteria biological denitrification module and halophilic denitrifying bacteria are added to promote denitrification. After denitrification, the wastewater enters the secondary MBR membrane, and the ammonia nitrogen and carbon source are further removed by controlling the residence time. Denitrification resin treatment: The final effluent passes through the denitrification resin tank, filled with modified denitrification resin to adsorb residual nitrates to achieve standard discharge; The modified denitrification resin comprises: sodium carboxymethyl starch, acrylamide and modified vinyl pyridine; The modified denitrification resin is prepared by grafting acrylamide and modified vinyl pyridine onto sodium carboxymethyl starch through reverse suspension polymerization, and then performing secondary cross-linking and curing and then grafting modification with thiosemicarbazide. The modified vinyl pyridine is prepared by quaternizing pyridyl ammonium salt with vinyl pyridine through 5-chloromethyl salicylaldehyde.

2. The full-scale treatment process for landfill leachate according to claim 1, characterized in that: The mass ratio of the sodium carboxymethyl starch, acrylamide and modified vinyl pyridine is 3:12-15:6-8.

3. The fully quantitative treatment process for landfill leachate according to claim 1, characterized in that: The modified denitrification resin comprises the following preparation steps: S1. Weigh sodium carboxymethyl starch, acrylamide, and modified vinyl pyridine in a mass ratio of 3:12-15:6-8; add sodium carboxymethyl starch to deionized water 40-45 times the mass of sodium carboxymethyl starch, stir to dissolve, add acrylamide and grafted vinyl pyridine, then add potassium persulfate 0.08-0.1 times the mass of sodium carboxymethyl starch and N, N-methylenebisacrylamide 0.004-0.006 times the mass of sodium carboxymethyl starch, stir evenly, and prepare a polymerization solution; then add the polymerization solution dropwise to the polymerization solution. The method comprises the following steps: adding epichlorohydrin in an amount of 0.2 to 0.3 times the mass of sodium carboxymethyl starch to a cyclohexane solution with a volume of 0.5 to 0.7 times the mass of the solution, stirring at a temperature of 30 to 40°C for 30 to 40 minutes, raising the temperature to 60 to 70°C, stirring and reacting for 2 to 2.5 hours to obtain a mixed mother liquor, and then adding the mixed mother liquor to a coagulation solution with a volume of 10 to 15 times the volume of the mixed mother liquor to solidify into balls, standing for 30 to 40 minutes, filtering and washing with deionized water for 3 to 5 times to obtain preliminary cross-linked microspheres, and then performing secondary cross-linking to obtain cross-linked microspheres; S2. Add thiosemicarbazide to anhydrous ethanol in an amount of 12 to 15 times the mass of thiosemicarbazide, stir evenly, then add cross-linked microspheres in an amount of 2 to 5 times the mass of thiosemicarbazide, then add acetic acid in an amount of 0.2 to 0.3 times the mass of thiosemicarbazide, then stir and reflux for 6 to 7 hours, filter, extract with ethanol through a Soxhlet extractor for 24 to 26 hours, and then vacuum dry to obtain a modified denitrification resin.

4. The full-scale treatment process for landfill leachate according to claim 3, characterized in that: The coagulation solution is prepared by mixing anhydrous sodium sulfate, sodium hydroxide, deionized water and anhydrous ethanol in a mass ratio of 1:1.2-1.4:22-25:0.15-0.2 and stirring evenly.

5. The full-scale treatment process for landfill leachate according to claim 3 is characterized in that: The cyclohexane solution is prepared by mixing cyclohexane and polycubic acid ester in a mass ratio of 75-80:1 and stirring them uniformly.

6. The fully quantitative treatment process for landfill leachate according to claim 3, characterized in that: The secondary crosslinking comprises the following preparation steps: extracting the preliminary crosslinked microspheres with ethanol using a Soxhlet extractor for 3 to 4 hours, then washing them with ethanol and deionized water for 3 to 5 times respectively, dehydrating them and then placing them in a sodium hydroxide aqueous solution with a pH of 13 that is 10 to 12 times the mass of the preliminary crosslinked microspheres, then adding epichlorohydrin that is 0.1 to 0.2 times the mass of the preliminary crosslinked microspheres, stirring and reacting at a temperature of 60 to 70° C. for 2 to 2.5 hours, taking them out, washing them with deionized water until neutral, and then dehydrating them to obtain crosslinked microspheres.

7. The fully quantitative treatment process for landfill leachate according to claim 3, characterized in that: The modified vinyl pyridine comprises the following preparation steps: adding vinyl pyridine to an acetonitrile solution with a mass of 10 to 12 times that of the vinyl pyridine, stirring evenly, dropwise adding 5-chloromethyl salicylaldehyde with a mass of 1.3 to 1.5 times that of the vinyl pyridine, stirring evenly, reacting at a temperature of 65 to 75° C. for 24 to 26 hours, and after the reaction is completed, rotary evaporation and then recrystallization through acetonitrile to obtain grafted vinyl pyridine.

8. The full-scale treatment process for landfill leachate according to claim 7, characterized in that: The acetonitrile solution is prepared by mixing acetonitrile and ethyl acetate in a volume ratio of 1:3-3.5 and stirring evenly.

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