A method for fully quantifying the treatment of leachate from a waste incineration power plant

Abstract

The present invention provides a method for fully quantifying the treatment of leachate from a waste incineration power plant, belonging to the technical field of wastewater treatment. The biochemical system adopted in this method can efficiently remove COD and ammonia nitrogen through anaerobic + A / O biochemistry, and MBR + nanofiltration can further concentrate the filtrate and desalt. The evaporation system can achieve deep concentration through two-stage MVR forced circulation evaporation, thereby realizing full quantification treatment. In addition, a modified polyethersulfone (PES) microporous membrane prepared by this method can greatly enhance the anti-pollution performance of the membrane and the separation efficiency of the membrane.

Description

Technical Field

[0001] The present invention belongs to the technical field of wastewater treatment, and particularly relates to a method for fully quantifying the treatment of leachate from a waste incineration power plant. Background Art

[0002] In the treatment of municipal solid waste by incineration, with the continuous increase in the amount of waste, a large amount of liquid is generated during the combustion process, which contains toxic substances with changed properties under high-temperature environments. Among them, the liquid content in kitchen waste is the largest, and the leachate generated during the incineration process is also the largest. Before combustion, the waste is stacked centrally, and the internal waste undergoes fermentation and decomposition to produce moisture. The leachate contains a large amount of pollutants and has a high concentration. If it flows freely without treatment, it will cause serious environmental pollution. The land polluted by the leachate is not conducive to plant growth. Therefore, in the treatment of municipal solid waste, leachate treatment is also required after incineration, otherwise secondary pollution will be caused. The leachate also emits stench, which pollutes the air. It is urgent to control it, as it affects water sources, land, air, etc., which is also a key issue to be solved currently.

[0003] CN202808539U provides a leachate treatment device for a waste incineration power plant with high treatment efficiency, low energy consumption, low investment, and small floor area. It combines physical and chemical, biochemical, and membrane filtration technologies.

[0004] CN207429802U provides a leachate treatment device for a waste power plant. It improves the leachate treatment efficiency and also has the advantages of good leachate treatment effect, low cost, good treatment effect, and convenient operation.

[0005] CN104355451A provides a new process for the resource utilization of the biochemical treatment effluent of leachate from a waste incineration power plant. MBR + flocculation + microfiltration + RO treatment (reuse of clear water + reuse of concentrated water and flocculation residue).

[0006] CN112607963A provides a system and method for fully quantifying the treatment of nanofiltration concentrate in waste leachate, realizing the reduction of concentrate, avoiding pipeline scaling during the reuse of concentrate, reducing the consumption of pulping lime, reducing the fly ash output, and being widely applicable to the upgrading of waste leachate treatment and the reduction treatment of leachate concentrate.

[0007] CN108483799A provides a leachate treatment process for a waste incineration power plant: adjustment - composite precipitation - water quality balancing - biodegradation - solid-liquid separation - nanofiltration - reverse osmosis.

[0008] CN105254122A provides a treatment method for leachate from a waste incineration power plant, which has high treatment efficiency, low energy consumption, a short process flow, and a high water production rate. Pretreatment - anaerobic UBF treatment - nitrification and denitrification treatment - ultrafiltration treatment - low-temperature distillation treatment.

[0009] CN114644428A provides a treatment process for leachate from a waste incineration power plant: raw water regulation - coagulation and sedimentation - hydrolysis acidification - contact oxidation - MBR separation.

[0010] CN114291972A provides a treatment system and method for leachate from a waste incineration power plant: mobile phone module - ultraviolet pretreatment module - MBR membrane treatment module.

[0011] CN112851002A provides a treatment system and method for full quantification of nanofiltration concentrate: ultrafiltration system - nanofiltration membrane system - high-efficiency separation membrane system - low-temperature evaporation system.

[0012] Characteristics of leachate from waste incineration power plants: high pollutant concentration, complex water quality components, and imbalance in the C, N, and P ratios. The membrane concentrate in conventional treatment is large in quantity, and backspraying will reduce the furnace temperature and affect power generation, so it cannot be backsprayed into the incinerator or reinjected into the landfill. The treatment of leachate from waste incineration power plants by single biochemical methods, membrane methods, etc. is restricted in practical applications, and other processes such as chemical oxidation, electro-oxidation method, catalytic oxidation, etc. have high operating costs. Summary of the Invention

[0013] The purpose of the present invention is to overcome the above deficiencies in the prior art, and provides a full-quantification treatment method for leachate from a waste incineration power plant, which combines the application of a biochemical system, a membrane system, a physical and chemical system, and an evaporation system to achieve full-quantification treatment of leachate.

[0014] To achieve the above purpose, the technical solution adopted by the present invention is:

[0015] A full-quantification treatment method for leachate from a waste incineration power plant, comprising the following steps:

[0016] (1) Regulation tank: The leachate from the waste incineration plant enters the regulation tank to balance the pH, adjust the influent water quality of the biochemical system, and supplement the nutrient sources required by the biochemical system;

[0017] (2) Anaerobic biochemistry: The water from the regulation tank flows by gravity to the anaerobic biochemical system to control the temperature and adjust the pH;

[0018] (3) A / O biochemistry: The anaerobic effluent enters the A / O system for nitrification and denitrification to achieve the nitrogen removal effect;

[0019] (4) MBR: The biologically treated effluent enters the MBR tank to enhance the removal of organic matter, remove ammonia nitrogen, effectively intercept microorganisms, and reduce sludge production;

[0020] (5) Nanofiltration: Adjust the pH. The nanofiltration permeate can be discharged as qualified water, and the concentrate enters the MVR forced circulation evaporation system;

[0021] (6) Two-stage MVR: The concentrate is treated by a two-stage MVR forced circulation evaporation system. After the evaporation mother liquor is concentrated, it enters the drying system for drying treatment, and the clear water is merged into the qualified water for discharge.

[0022] Preferably, the pH is controlled at 6 - 8 in steps (1) - (5).

[0023] Preferably, in step (1), it needs to stay in the adjustment tank for more than 24 hours.

[0024] Preferably, in step (2), the anaerobic biochemical temperature is controlled at 20 - 30 °C.

[0025] Preferably, in step (2), the anaerobic biochemical residence time is 5 - 15 days.

[0026] Preferably, in step (3), the A / O biochemical residence time is 10 - 20 days.

[0027] Furthermore, in the nanofiltration operation of step (5), the filter is preferably a modified polyethersulfone (PES) microporous membrane, and its preparation method is as follows:

[0028] S1. Irradiation: By weight, irradiate 100 - 200 parts of polyethersulfone (PES) microporous membrane under an irradiation source for 10 - 30 minutes;

[0029] S2. Crosslinking graft reaction: Add 8 - 15 parts of 3-(2-carboxyvinyl)phenylboronic acid, 0.05 - 0.5 parts of copper acrylate, 0.05 - 0.6 parts of quaternary ammonium salt, 500 - 800 parts of DMF to a stirring kettle, stir and react at 30 - 50 °C for 10 - 25 minutes, then add 70 - 120 parts of the irradiated polyethersulfone (PES) microporous membrane to the above materials; stir and react at 75 - 85 °C for 30 - 100 minutes, take out the microporous membrane, and then irradiate it under an irradiation source for 10 - 30 minutes, wash with water, and dry to obtain the modified polyethersulfone (PES) microporous membrane.

[0030] Preferably, the irradiation source for the irradiation is preferably a cobalt source, an electron beam, or an ultraviolet lamp, more preferably a cobalt source; the irradiation dose is preferably above 20 kGy, more preferably 50 - 100 kGy, specifically 20 kGy, 25 kGy, 30 kGy, 35 kGy, 40 kGy, 45 kGy, 50 kGy; the irradiation temperature is preferably 20 - 40 °C.

[0031] Preferably, the irradiation process is carried out in an air, nitrogen or noble gas atmosphere, preferably in a nitrogen or noble gas atmosphere.

[0032] Preferably, the quaternary ammonium salt is selected from methacryloyloxyethyl trimethyl ammonium chloride, methacryloyloxyethyl dimethyl hexadecyl ammonium bromide or methacryloyloxyethyl dimethyl benzyl ammonium chloride.

[0033] Preparation mechanism of the modified polyethersulfone (PES) microporous membrane in the method for total quantification treatment of landfill leachate in a waste incineration power plant of the present invention:

[0034] Through the free radical polymerization reaction of 3-(2-carboxyvinyl)phenylboronic acid, copper acrylate, quaternary ammonium salt and the PES microporous membrane with free radicals on the surface, the monomers are polymerized onto the membrane surface, realizing the specific selection of C, N, and P in the landfill leachate in the waste incineration power plant, which is beneficial to blocking fine particles on the membrane surface, thereby improving the filtration efficiency.

[0035] A method for total quantification treatment of landfill leachate in a waste incineration power plant of the present invention has the following remarkable effects compared with the prior art:

[0036] 1. The biochemical system adopted in this method can efficiently remove COD and ammonia nitrogen through anaerobic + A / O biochemistry.

[0037] 2. The membrane system adopted in this method uses MBR + nanofiltration to further concentrate the filtrate and desalt.

[0038] 3. The evaporation system adopted in this method can achieve deep concentration through two-stage MVR forced circulation evaporation, thereby realizing total quantification treatment.

[0039] 4. The modified polyethersulfone (PES) microporous membrane adopted in this method enhances the anti-fouling performance of the membrane: the modification can make the surface of the ultrafiltration membrane present extremely small pore sizes and high fineness, thereby enhancing the anti-fouling performance of the membrane. Thus, the stability and operating life of the membrane are improved.

[0040] 5. The modified polyethersulfone (PES) microporous membrane adopted in this method improves the separation efficiency of the membrane: it can make the sol and colloid on the surface of the ultrafiltration membrane disperse evenly, reducing the interlayer voids, thereby improving the separation efficiency of the membrane. Description of the Drawings

[0041] Figure 1 It is a process flow block diagram of this method. Detailed Embodiments

[0042] To make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to embodiments and drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0043] Example 1

[0044] A method for full-quantification treatment of leachate from a waste incineration power plant includes the following steps:

[0045] (1) Regulation tank: The leachate from the waste incineration plant enters the regulation tank to balance the pH, adjust the influent water quality of the biochemical system, and supplement the nutrient sources required by the biochemical system;

[0046] (2) Anaerobic biochemistry: The water from the regulation tank flows by gravity to the anaerobic biochemical system to control the temperature and adjust the pH;

[0047] (3) A / O biochemistry: The anaerobic effluent enters the A / O system for nitrification and denitrification to achieve the nitrogen removal effect;

[0048] (4) MBR: The biochemical effluent enters the MBR tank to strengthen the removal of organic matter, remove ammonia nitrogen, effectively intercept microorganisms, and reduce the sludge production;

[0049] (5) Nanofiltration: Adjust the pH, and the nanofiltration clear water can be discharged as qualified water, and the concentrated water enters the MVR forced circulation evaporation system;

[0050] (6) Two-stage MVR: The concentrated water is treated by the two-stage MVR forced circulation evaporation system. After the evaporation mother liquor is concentrated, it enters the drying system for drying treatment, and the clear water is discharged by merging into the qualified water.

[0051] In steps (1)-(5) above, the pH needs to be controlled at 7.

[0052] In step (1) above, it is required to stay in the regulation tank for more than 24 hours.

[0053] In step (2) above, the anaerobic biochemistry temperature is controlled at 20 °C.

[0054] In step (2) above, the anaerobic biochemistry residence time is 10 days.

[0055] In step (3) above, the A / O biochemistry residence time is 15 days.

[0056] In the nanofiltration operation of step (5), the filter is selected as a modified polyethersulfone (PES) microporous membrane, and its preparation method is:

[0057] S1. Irradiation: Irradiate 100 kg of polyethersulfone (PES) microporous membrane under an irradiation source for 20 minutes;

[0058] S2. Crosslinking grafting reaction: Add 10 kg of 3-(2-carboxyvinyl)phenylboronic acid, 0.1 kg of copper acrylate, 0.1 kg of quaternary ammonium salt, and 500 kg of DMF into a stirring kettle. Stir and react at 30 °C for 25 minutes, then add 70 kg of irradiated polyethersulfone (PES) microporous membrane into the above materials; stir and react at 75 °C for 50 minutes, take out the microporous membrane, and then irradiate it under an irradiation source for 10 minutes, wash it with water, and dry it to obtain a modified polyethersulfone (PES) microporous membrane.

[0059] The irradiation source for the irradiation is preferably a cobalt source, an electron beam or an ultraviolet lamp, more preferably a cobalt source; the dose of the irradiation is 20 kGy; the temperature of the irradiation is preferably 40 °C.

[0060] The irradiation process is carried out in a nitrogen atmosphere.

[0061] The quaternary ammonium salt is selected from methacryloyloxyethyl trimethyl ammonium chloride.

[0062] Example 2

[0063] A method for the full-quantification treatment of leachate from a waste incineration power plant includes the following steps:

[0064] (1) Regulation tank: The leachate from the waste incineration plant enters the regulation tank to balance the pH, adjust the influent water quality of the biochemical system, and supplement the nutrient sources required by the biochemical system;

[0065] (2) Anaerobic biochemistry: The water from the regulation tank flows by gravity to the anaerobic biochemical system to control the temperature and adjust the pH;

[0066] (3) A / O biochemistry: The anaerobic effluent enters the A / O system for nitrification and denitrification to achieve the nitrogen removal effect;

[0067] (4) MBR: The biochemical effluent enters the MBR tank to intensively remove organic matter, remove ammonia nitrogen, effectively intercept microorganisms, and reduce sludge production;

[0068] (5) Nanofiltration: Adjust the pH, and the nanofiltration clear water can be discharged as qualified water, and the concentrated water enters the MVR forced circulation evaporation system;

[0069] (6) Two-stage MVR: The concentrated water is treated by a two-stage MVR forced circulation evaporation system. After the evaporation mother liquor is concentrated, it enters the drying system for drying treatment, and the clear water is merged into the qualified water for discharge.

[0070] The pH needs to be controlled at 7 in steps (1)-(5).

[0071] It is required to stay in the regulation tank for more than 24 hours in step (1).

[0072] The anaerobic biochemistry temperature is controlled at 25 °C in step (2).

[0073] In step (2), the anaerobic biochemical residence time is 10 days.

[0074] In step (3), the A / O biochemical residence time is 10 days.

[0075] In the nanofiltration operation of step (5), the filter uses a modified polyethersulfone (PES) microporous membrane, and its preparation method is as follows:

[0076] S1. Irradiation: Irradiate 150 kg of polyethersulfone (PES) microporous membrane under an irradiation source for 20 minutes;

[0077] S2. Crosslinking graft reaction: Add 12 kg of 3-(2-carboxyvinyl)phenylboronic acid, 0.25 kg of copper acrylate, 0.3 kg of quaternary ammonium salt, 650 kg of DMF to a stirring kettle, stir and react at 40 °C for 15 minutes, and then add 100 kg of irradiated polyethersulfone (PES) microporous membrane to the above materials; Stir and react at 80 °C for 75 minutes, take out the microporous membrane, and then irradiate it under an irradiation source for 20 minutes, wash it with water, and dry it to obtain a modified polyethersulfone (PES) microporous membrane.

[0078] The irradiation source for the irradiation is preferably a cobalt source, an electron beam or an ultraviolet lamp, more preferably a cobalt source; the irradiation dose is preferably 35 kGy; the irradiation temperature is preferably 30 °C.

[0079] The irradiation process is carried out in a nitrogen atmosphere.

[0080] The quaternary ammonium salt is selected from methacryloyloxyethyl dimethylhexadecyl ammonium bromide.

[0081] Example 3

[0082] A method for fully quantifying the treatment of leachate from a waste incineration power plant includes the following steps:

[0083] (1) Regulation tank: The leachate from the waste incineration plant enters the regulation tank to balance the pH, adjust the influent water quality of the biochemical system, and supplement the nutrients required by the biochemical system;

[0084] (2) Anaerobic biochemistry: The water from the regulation tank flows by gravity to the anaerobic biochemical system to control the temperature and adjust the pH;

[0085] (3) A / O biochemistry: The anaerobic effluent enters the A / O system for nitrification and denitrification to achieve the denitrification effect;

[0086] (4) MBR: The biochemical effluent enters the MBR tank to strengthen the removal of organic matter, remove ammonia nitrogen, effectively intercept microorganisms, and reduce sludge production;

[0087] (5) Nanofiltration: Adjust the pH. The nanofiltration permeate can be discharged as qualified water, and the concentrate enters the MVR forced circulation evaporation system.

[0088] (6) Two-stage MVR: The concentrate is treated by a two-stage MVR forced circulation evaporation system. After the evaporation mother liquor is concentrated, it enters the drying system for drying treatment, and the permeate is merged into the qualified water for discharge.

[0089] In steps (1)-(5) above, the pH needs to be controlled at 7.

[0090] In step (1) above, it needs to stay in the adjustment tank for more than 24 hours.

[0091] In step (2) above, the anaerobic biochemical temperature is controlled at 25 °C.

[0092] In step (2) above, the anaerobic biochemical residence time is 10 days.

[0093] In step (3) above, the A / O biochemical residence time is 20 days.

[0094] In the nanofiltration operation of step (5) above, the filter uses a modified polyethersulfone (PES) microporous membrane, and its preparation method is as follows:

[0095] S1. Irradiation: Irradiate 200 kg of polyethersulfone (PES) microporous membrane under an irradiation source for 30 minutes.

[0096] S2. Crosslinking graft reaction: Add 15 kg of 3-(2-carboxyvinyl)phenylboronic acid, 0.5 kg of copper acrylate, 0.6 kg of quaternary ammonium salt, and 800 kg of DMF to a stirring kettle, stir and react at 50 °C for 25 minutes, then add 120 kg of the irradiated polyethersulfone (PES) microporous membrane to the above materials; stir and react at 85 °C for 100 minutes, take out the microporous membrane, and then irradiate it under an irradiation source for 30 minutes, wash it with water, and dry it to obtain a modified polyethersulfone (PES) microporous membrane.

[0097] The irradiation source for the irradiation is preferably a cobalt source, an electron beam or an ultraviolet lamp, more preferably a cobalt source; the irradiation dose is preferably 50 kGy; the irradiation temperature is preferably 20 °C.

[0098] The irradiation process is carried out in a nitrogen atmosphere.

[0099] The quaternary ammonium salt is selected from methacryloyloxyethyl dimethylbenzyl ammonium chloride.

[0100] Example evaluation

[0101] Table 1 Water quality indicators of leachate from waste incineration power plants in Examples 1-3

[0102] Serial number pH COD (mg / L) <![CDATA[NH3-N (mg / L)]]> Example 1 5.9 55301 1298 Example 2 6.6 36541 1333 Example 3 6.3 50156 1720

[0103] The original water samples of the above Examples 1-3 were respectively diluted 7 times with the nanofiltration effluent of this system.

[0104] Table 2 Operating effects

[0105]

[0106]

[0107] The specific embodiments described above have further elaborated on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for full - quantification treatment of leachate from a waste incineration power plant, comprising the following steps: (1) Regulation tank: The leachate from the waste incineration plant enters the regulation tank to balance the pH, adjust the influent water quality of the biochemical system, and supplement the nutrient sources required by the biochemical system; (2) Anaerobic biochemistry: The water from the regulation tank flows by gravity to the anaerobic biochemical system to control the temperature and adjust the pH; (3) A / O biochemistry: The anaerobic effluent enters the A / O system for nitrification and denitrification to achieve the nitrogen removal effect; (4) MBR: The biochemical effluent enters the MBR tank to intensify the removal of organic matter, remove ammonia nitrogen, effectively intercept microorganisms, and reduce sludge production; (5) Nanofiltration: Adjust the pH, and the nanofiltration clear water can be discharged as qualified water, while the concentrated water enters the MVR forced - circulation evaporation system; (6) Two - stage MVR: The concentrated water is treated by the two - stage MVR forced - circulation evaporation system. After the evaporation mother liquor is concentrated, it enters the drying system for drying treatment, and the clear water is merged into the qualified water for discharge; In the nanofiltration operation of step (5), a modified polyethersulfone microporous membrane is selected as the filter, and its preparation method is as follows: S1. Irradiation: By weight, 100 - 200 parts of the polyethersulfone microporous membrane are irradiated under an irradiation source for 10 - 30 minutes; S2. Cross - linking grafting reaction: Add 8 - 15 parts of 3 - (2 - carboxyvinyl)phenylboronic acid, 0.05 - 0.5 parts of copper acrylate, 0.05 - 0.6 parts of quaternary ammonium salt, 500 - 800 parts of DMF into a stirring kettle, stir and react at 30 - 50 °C for 10 - 25 minutes, then add 70 - 120 parts of the irradiated polyethersulfone microporous membrane into the above materials; stir and react at 75 - 85 °C for 30 - 100 minutes, take out the microporous membrane, and then irradiate it under the irradiation source for 10 - 30 minutes, wash it with water, and dry it to obtain the modified polyethersulfone microporous membrane; the irradiation source is a cobalt source, an electron beam or an ultraviolet lamp; the irradiation dose is above 20 kGy, the irradiation temperature is 20 - 40 °C; the irradiation is carried out in nitrogen; the quaternary ammonium salt is selected from methacryloyloxyethyltrimethylammonium chloride or methacryloyloxyethyldimethylhexadecylammonium bromide or methacryloyloxyethyldimethylbenzylammonium chloride.

2. A method for full - quantification treatment of leachate from a waste incineration power plant according to claim 1, characterized in that, In steps (1) - (5), the pH needs to be controlled at 6 - 8.

3. A method for fully quantifying the treatment of leachate from a waste incineration power plant according to claim 1, characterized in that In step (1), it needs to stay in the regulation tank for more than 24 hours.

4. A method for fully quantifying the treatment of leachate from a waste incineration power plant according to claim 1, characterized in that, In step (2), the anaerobic biochemistry temperature is controlled at 20 - 30 °C.

5. A method for full-quantification treatment of leachate from a waste incineration power plant according to claim 1, characterized in that In step (2), the anaerobic biochemistry residence time is 5 - 15 days.

6. A method for fully quantifying the treatment of leachate from a waste incineration power plant according to claim 1, characterized in that, In step (3), the A / O biochemistry residence time is 10 - 20 days.

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