Equipment for deeply treating landfill leachate through photocatalysis and use method

Abstract

The invention provides equipment for deeply treating landfill leachate through photocatalysis and a use method. A bioreactor is communicated with a liquid inlet pipe of a photocatalysis reaction tank, and a liquid outlet pipe of the photocatalysis reaction tank is communicated with an acid-base neutralization tank; a support is arranged at an opening in the top of the photocatalytic reaction tank, a plurality of solar collecting lenses are flatly laid on the upper surface of the support, a plurality of reflectors are laid at the bottom of the photocatalytic reaction tank, a chemical feeding pipe and a water feeding pipe are further arranged in the photocatalytic reaction tank, and a plurality of nozzles are arranged on the chemical feeding pipe; a plurality of stirrers are arranged at the bottom or one side of the bottom of the photocatalytic reaction tank. Advanced treatment is carried out on the landfill leachate MBR treatment liquid, a photo-thermal synergistic persulfate oxidation system is adopted for advanced treatment, the reaction system runs stably, and the degradation efficiency of ammonia nitrogen and organic pollutants in wastewater is effectively improved.

Description

Technical Field

[0001] The invention relates to the field of sewage treatment, and in particular to a device for photocatalytic deep treatment of garbage leachate and a use method thereof. Background Art

[0002] In recent years, with the rapid development of the economy and the sharp increase in population, the output of solid waste has increased. According to the "2020 China Ecological Environment Statistical Yearbook" of the Ministry of Ecological Environment Protection, my country's domestic waste treatment volume is 270 million tons, of which 220 million tons are landfilled. A large amount of leachate formed by rainwater infiltrating into landfills poses a huge threat to ecological and environmental safety. Therefore, it is urgent to solve the problem of leachate, and it is crucial to carry out research on related technologies to ensure the health of the ecological environment.

[0003] Landfill leachate contains a variety of difficult-to-degrade pollutants, mainly humic acid, and high concentrations of ammonia nitrogen (NH4 + -N), heavy metals, chlorinated organic compounds, soluble salts, etc., so it is very difficult to effectively treat landfill leachate. The main technologies for treating landfill leachate include conventional biological treatment, physical and chemical treatment, reinjection treatment technology and membrane treatment technology. Biological treatment technologies include activated sludge method, aerobic stabilization tank, rotating biological contactor, etc. The advantages are simple operation, low cost and no secondary pollution. However, the method of biological treatment technology is only effective for leachate with high five-day biochemical oxygen demand (BOD5) and good biodegradability (BOD5 / COD>0.3), and the biodegradability will continue to decrease with the increase of treatment time. Reinjection treatment is to spray the leachate generated by the landfill to the surface of the landfill, part of which evaporates naturally, and at the same time utilizes the purification effect of the landfill's own microorganisms and the physical and chemical adsorption of the soil. The facilities are simple and the cost is low, but it is easy to cause blockage of the soil layer, and the concentration of pollutants is continuously enriched, causing serious secondary pollution. Membrane treatment technologies include reverse osmosis, nanofiltration, combined membrane systems, etc., which require reasonable screening, interception and adsorption steps to remove difficult-to-degrade organic matter from the leachate. They face problems such as high operating costs and membrane clogging, and their application is limited. In addition, the pollutants are not truly degraded, which will cause secondary pollution.

[0004] Recently, advanced oxidation processes (AOPs) have attracted wide attention because they can degrade difficult-to-treat macromolecular organic matter in wastewater into small molecular substances or even directly mineralize them. Among them, advanced oxidation processes based on sulfate radicals (SR-AOPs) have been a hot topic in recent years. Persulfates include monopersulfate (PMS) and peroxydisulfate (PS), but they are relatively stable at room temperature and have limited ability to oxidize and degrade organic matter in an unactivated state. However, certain activation methods (such as heat, transition metals, ultrasound, microwaves, ultraviolet light, inorganic anions, etc.) can make persulfates produce highly oxidizing sulfate radicals (SO4· - ), which can effectively remove COD, chromaticity and NH4 + -N, in recent years, is often used as a pretreatment method for landfill leachate or as a supplementary deep treatment method. Common landfill leachate treatment systems include pretreatment units, biochemical oxidation units, advanced oxidation units and full-scale treatment units, which are arranged in sequence. In the past, advanced oxidation units required additional energy (ultrasound, microwave, ultraviolet, etc.) or catalysts, but their high energy consumption or secondary pollution is still a problem. Therefore, it is necessary to improve a green and low-energy advanced oxidation system. Summary of the invention

[0005] The main purpose of the present invention is to provide a device and a method for using photocatalytic deep treatment of landfill leachate, so as to solve the common landfill leachate treatment system, including a pretreatment unit, a biochemical oxidation unit, an advanced oxidation unit and a full-quantity treatment unit arranged in sequence. The previous advanced oxidation units required additional introduction of energy (ultrasound, microwave, ultraviolet, etc.) or addition of catalysts, but their energy consumption was too high or secondary pollution was still a difficult problem.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a device for photocatalytic deep treatment of landfill leachate, wherein the bioreactor is connected to the liquid inlet pipe of the photocatalytic reaction tank, and the liquid outlet pipe of the photocatalytic reaction tank is connected to the acid-base neutralization tank; The top opening of the photocatalytic reaction pool is provided with a bracket, a plurality of solar concentrators are laid flat on the upper surface of the bracket, a plurality of reflectors are laid on the bottom of the photocatalytic reaction pool, a dosing pipe and a water adding pipe are also provided inside the photocatalytic reaction pool, and a plurality of nozzles are provided on the dosing pipe; A plurality of stirrers are arranged at the bottom or one side of the bottom of the photocatalytic reaction tank.

[0007] In a preferred embodiment, a dosing pipe is provided on one side of the photocatalytic reaction pool, and the dosing pipe is connected to the dosing pipe through a third valve.

[0008] In the preferred embodiment, the mixing chamber is connected to the dosing pipe via a dosing pump; The mixing chamber is used to mix water and medicine.

[0009] In a preferred embodiment, a sunlight introduction system is also provided on the photocatalytic reaction pool, a light guide strip is provided on the inner side wall or bottom of the photocatalytic reaction pool, and the sunlight introduction system is connected to the light guide strip via an optical fiber.

[0010] In a preferred embodiment, the photocatalytic reaction pool includes an outer wall and an inner wall, and an insulation layer is provided between the outer wall and the inner wall.

[0011] In a preferred embodiment, a second pump body is provided inside the bioreactor, the second pump body is connected to a liquid inlet pipe, and a second valve is provided on the liquid inlet pipe.

[0012] In a preferred embodiment, a first pump body is provided at the bottom of the photocatalytic reaction tank, the first pump body is connected to a liquid outlet pipe, and a first valve is provided on the liquid outlet pipe.

[0013] In the preferred embodiment, the liquid outlet pipe is connected to the bottom of the acid-base neutralization tank, and a rotatable stirring scraper is provided inside the acid-base neutralization tank.

[0014] In the preferred embodiment, the bottom of the acid-base neutralization tank is connected to the sludge tank.

[0015] The method includes: S1, 1t-3t of landfill leachate MBR treated liquid is introduced from the MBR into the photocatalytic reaction tank through the liquid inlet pipe and the second valve. At this time, the photocatalytic reaction tank is used as a regulating tank to collect the landfill leachate MBR treated liquid, adopting the three-in-one standby method; S2, synchronously start the dosing pump, add 2kg-8kg of PS into the photocatalytic reaction tank through the dosing pipe, and contact with the landfill leachate MBR treatment liquid; S3, synchronously start the agitator at the bottom of the reaction tank to evenly mix the landfill leachate MBR treatment liquid and the reagent; S4, the sunlight passes through the light refraction mechanism composed of the solar concentrator and the reflector, and at the same time the sunlight introduction system introduces the sunlight into the photocatalytic reaction pool; Irradiate the reaction liquid in the photocatalytic reaction tank. Sunlight irradiates PS. Under the sunlight condition, PS is activated to produce SO4·- and hydroxyl radicals (·OH), which preferentially oxidize small molecular organic pollutants. Most of the pollutants in the MBR treatment liquid are mineralized to produce CO2 and H2O, thereby reducing COD, BOD and NH4+-N. S5. With the irradiation of sunlight, the temperature in the photocatalytic reaction pool rises, providing activation energy to PS by heating, thereby generating SO4·- and ·OH, and degrading pollutants in the MBR treatment liquid; S6. After a reaction cycle is completed, the reaction liquid in the photocatalytic reaction pool is introduced into the acid-base neutralization pool through the liquid outlet pipe and the first valve, and the pH value is adjusted before the discharge can meet the standards; S7. Sunlight irradiates the reaction liquid in the photocatalytic reaction pool through the light refraction mechanism composed of solar concentrators and reflectors. The temperature in the photocatalytic reaction pool rises. The combination of sunlight and heating activates PS to produce SO4. - and ·OH, thereby reducing COD, BOD and NH4 + -N.

[0016] The present invention provides a device and a method for using photocatalytic deep treatment of landfill leachate. The present invention mainly aims at landfill leachate containing a variety of difficult-to-degrade pollutants, which are difficult to be effectively degraded by conventional processes. The landfill leachate MBR treatment liquid is deeply treated and a photothermal synergistic persulfate oxidation system is used for deep treatment. The reaction system operates stably and effectively improves the degradation efficiency of ammonia nitrogen and organic pollutants in wastewater.

[0017] The present invention adopts a small photocatalytic reaction pool to regulate and store the MBR treatment liquid, and uses clean energy sunlight and solar thermal energy to activate persulfate to produce strong active factors (AOPs), thereby degrading pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 It is a process flow chart of the present invention; Figure 2 This is a schematic diagram of the docking of the photocatalytic reaction pool of the present invention; Figure 3 Schematic diagram of the photocatalytic reaction pool of the present invention; Figure 4 This is a diagram showing the arrangement of the reflectors at the bottom of the photocatalytic reaction pool of the present invention; Figure 5 It is the COD and chromaticity reaction chart in Example 4 of the present invention; Figure 6 is NH4 in Example 4 of the present invention + -N reaction chart; Figure 7 is a PCU reaction chart in Example 4 of the present invention; Figure 8 It is the COD and chromaticity reaction chart in Example 5 of the present invention; Fig. 9 is NH4 in Example 5 of the present invention + -N reaction chart; Fig.10 This is a PCU reaction chart in Example 5 of the present invention. In the figure: photocatalytic reaction tank 1; outer wall 101; insulation layer 102; inner wall 103; solar concentrator 2; bracket 3; dosing pipe 4; agitator 5; reflector 6; dosing pipe 7; third valve 8; liquid inlet pipe 9; liquid outlet pipe 10; first valve 11; second valve 12; sunlight introduction system 13; optical fiber 14; light guide strip 15; first pump body 16; acid-base neutralization tank 17; stirring scraper 18; sludge tank 19; bioreactor 20; second pump body 21; dosing pump 22; mixing chamber 23. DETAILED DESCRIPTION

[0019] Example 1 like Figure 1-10 As shown, a device for photocatalytic deep treatment of landfill leachate, the bioreactor 20 is connected to the liquid inlet pipe 9 of the photocatalytic reaction tank 1, and the liquid outlet pipe 10 of the photocatalytic reaction tank 1 is connected to the acid-base neutralization tank 17; The top opening of the photocatalytic reaction pool 1 is provided with a bracket 3, a plurality of solar concentrators 2 are laid flat on the upper surface of the bracket 3, a plurality of reflectors 6 are laid on the bottom of the photocatalytic reaction pool 1, a dosing pipe 4 and a water adding pipe are also provided inside the photocatalytic reaction pool 1, and a plurality of nozzles are provided on the dosing pipe 4; A plurality of stirrers 5 are provided at the bottom or one side of the bottom of the photocatalytic reaction tank 1 .

[0020] In the previous stage of the treatment process of the bioreactor 20, the generated liquid output is connected to the photocatalytic reaction tank 1 through the liquid inlet pipe 9 to transport the landfill leachate MBR treatment liquid to be treated.

[0021] The core processing unit of the photocatalytic reaction pool 1 has the following key features: Liquid inlet pipe 9: receives liquid from the bioreactor.

[0022] The treated liquid from the liquid outlet pipe 10 is discharged to the acid-base neutralization tank 17 for subsequent treatment.

[0023] The bracket 3 is located at the top, supporting and fixing a plurality of solar concentrators 2, which may be concave concave mirrors or convex lenses, for focusing sunlight to enhance the lighting effect.

[0024] The reflector 6 is laid on the bottom of the pool and fixed by welding, which can reflect light into the pool, increase the coverage and intensity of light, and promote photocatalytic reaction.

[0025] The dosing pipe 4 is equipped with a nozzle for evenly spreading the agent to the liquid in the pool to promote the decomposition of pollutants.

[0026] The water adding pipe adds water to maintain the liquid level or dilute the liquid concentration.

[0027] The agitator 5 is arranged at the bottom of the tank or at one side thereof to ensure that the liquid, the MBR treatment liquid and the reagent are fully mixed to improve the reaction efficiency.

[0028] The solar concentrator and reflector work together to not only provide the necessary lighting conditions to activate the photocatalyst, but also locally heat the reaction liquid through the focusing and reflection effects of light, which may further accelerate chemical reactions and microbial activities.

[0029] The solar concentrator 2 includes but is not limited to a concave concave mirror and a convex lens, is supported by an aluminum alloy bracket 3, and is located above the photocatalytic reaction pool 1.

[0030] The reflector 6 is located at the bottom wall of the photocatalytic reaction tank and is fixed to the bottom wall of the photocatalytic reaction tank by welding. The light refraction mechanism composed of the solar concentrator and the reflector is used to illuminate and heat the landfill leachate MBR treatment liquid and the reagent in the reaction tank.

[0031] In the preferred embodiment, a dosing pipe 7 is provided on one side of the photocatalytic reaction pool 1, and the dosing pipe 7 is connected to the dosing pipe 4 through a third valve 8. The mixing chamber 23 is connected to the dosing pipe 7 through a dosing pump 22; the mixing chamber 23 is used to mix water and the reagent.

[0032] The dosing pipe 7 is added to one side of the photocatalytic reaction pool 1 as another reagent adding path, which enhances the flexibility of the system in controlling the reagent delivery.

[0033] The third valve 8 connects the dosing pipe 4 and the dosing pipe 7, so that the operator can choose to add the reagent directly into the pool or pre-mix it through the mixing bin according to needs.

[0034] The main function of the mixing chamber 23 is to ensure that the reagent and water are fully mixed and uniform. This is very important for improving the reaction efficiency of the reagent, because the uniformly dispersed reagent can more effectively contact and react with the target pollutant.

[0035] The dosing pump 22 is installed between the mixing chamber 23 and the dosing pipe 7, and is responsible for transporting the evenly mixed liquid medicine from the mixing chamber to the photocatalytic reaction tank. The use of the pump ensures that the liquid medicine can be added to the reaction tank at a stable flow rate and pressure, further optimizing the reaction conditions.

[0036] In a preferred embodiment, a sunlight introduction system 13 is further provided on the photocatalytic reaction pool 1 , and a light guide bar 15 is provided on the inner side wall or bottom of the photocatalytic reaction pool 1 . The sunlight introduction system 13 is connected to the light guide bar 15 via an optical fiber 14 .

[0037] The purpose of the sunlight introduction system 13 is to maximize the collection and utilization of natural sunlight. It may be one or a series of devices installed outside the reaction pool, specifically used to capture sunlight and introduce it into the system.

[0038] The optical fiber 14 serves as a bridge between the sunlight introduction system and the interior of the reaction pool. The optical fiber can efficiently transmit light, and even if the sunlight does not directly irradiate every part of the reaction pool, it can ensure that the light is evenly distributed to the required position. The optical fiber has good light transmission performance, transmits light almost without loss, and improves energy utilization.

[0039] The light guide bar 15 is installed on the side wall or bottom of the photocatalytic reaction pool, receives the light transmitted by the optical fiber, and diffuses the light evenly to every corner inside the reaction pool through its design characteristics such as high reflective materials or scattering structures. This not only increases the coverage of light, but also ensures that the light distribution inside the reaction pool is more uniform, thereby improving the efficiency and effect of the photocatalytic reaction.

[0040] In a preferred embodiment, the photocatalytic reaction pool 1 includes an outer wall 101 and an inner wall 103 , and a heat-insulating layer 102 is provided between the outer wall 101 and the inner wall 103 .

[0041] The outer wall 101 is the outermost structure of the reaction tank and is in direct contact with the external environment. Its design needs to take weather resistance and protection into consideration to protect the internal structure from external factors.

[0042] The inner wall 103 is in direct contact with the liquid inside the reaction tank and the photocatalytic process, and is the direct interface where the reaction occurs. Its material needs to have corrosion resistance and photochemical resistance to adapt to the conditions of the photocatalytic reaction.

[0043] The insulation layer 102 is located between the outer wall 101 and the inner wall 103, and is made of a material with poor thermal conductivity to form an effective heat insulation barrier. The main function of this layer is to reduce the transfer of heat through the pool wall and maintain the internal temperature of the reaction pool stable. Especially when a certain temperature needs to be maintained to optimize the efficiency of the photocatalytic reaction, the role of the insulation layer is particularly critical. It can prevent heat loss caused by low external temperatures, or reduce the impact of high external temperatures on the internal reaction environment in a hot environment, thereby saving energy and ensuring reaction efficiency.

[0044] In a preferred embodiment, a second pump body 21 is provided inside the bioreactor 20 . The second pump body 21 is connected to the liquid inlet pipe 9 . A second valve 12 is provided on the liquid inlet pipe 9 .

[0045] The second pump body 21 is installed inside the bioreactor 20. Its main function is to provide power to extract the treatment liquid in the bioreactor and transport it through the pipeline. The existence of the pump body ensures that the liquid can overcome gravity and resistance and be stably and effectively transferred to the next treatment link.

[0046] The liquid inlet pipe 9 is an important channel connecting the bioreactor 20 and the photocatalytic reaction pool 1 , and is responsible for transmitting the liquid processed by the second pump body 21 .

[0047] The second valve 12 is arranged on the liquid inlet pipe 9, and this valve serves as a control element, allowing the operator to adjust or cut off the flow of liquid to the photocatalytic reaction tank 1. The flexibility of the valve is essential to maintain the stability of the liquid flow in the system and adapt to different processing requirements, such as being able to respond quickly during maintenance, flow adjustment or emergency response.

[0048] In a preferred embodiment, a first pump body 16 is provided at the bottom of the photocatalytic reaction tank 1 . The first pump body 16 is connected to a liquid outlet pipe 10 . A first valve 11 is provided on the liquid outlet pipe 10 .

[0049] The first pump body 16 is installed at the bottom of the photocatalytic reaction tank, and its function is to pump the photocatalytically treated liquid out of the tank bottom. The first pump body ensures that the treated liquid can be efficiently transported to the next treatment stage or discharged even when the treated liquid volume is large and the density may be increased due to the increase of suspended solids.

[0050] The liquid outlet pipe 10 connects the first pump body 16 with the subsequent processing link or discharge point, and is a channel for the treated liquid to be output.

[0051] The first valve 11 is arranged on the liquid outlet pipe 10 to control the discharge or transfer of the liquid. The opening and closing of the valve can flexibly adjust the liquid flow rate, realize the precise control of the treatment process, and provide necessary operations when maintenance or temporary stop of liquid output is required.

[0052] In the preferred embodiment, the liquid outlet pipe 10 is connected to the bottom of the acid-base neutralization tank 17, and a rotatable stirring scraper 18 is provided inside the acid-base neutralization tank 17. The bottom of the acid-base neutralization tank 17 is connected to the sludge tank 19.

[0053] The method includes: S1, 1t-3t of landfill leachate MBR treated liquid is introduced from the MBR into the photocatalytic reaction pool 1 through the liquid inlet pipe 9 and the second valve 12. At this time, the photocatalytic reaction pool 1 is used as a regulating pool to collect the landfill leachate MBR treated liquid, adopting the three-in-one standby method; S2, synchronously start the dosing pump 22, add 2kg-8kg of PS into the photocatalytic reaction tank 1 through the dosing pipe 4, and contact with the landfill leachate MBR treatment liquid; MBR is the abbreviation of "Membrane BioReactor". It is a highly efficient water treatment technology that combines biological treatment (mainly activated sludge process) with membrane filtration technology for wastewater treatment and reuse.

[0054] S3, synchronously start the agitator 5 at the bottom of the reaction tank to evenly mix the landfill leachate MBR treatment liquid and the reagent; S4, sunlight passes through the light refraction mechanism composed of the solar concentrator 2 and the reflector 6, and at the same time the sunlight introduction system 13 introduces the sunlight into the photocatalytic reaction pool 1; Irradiate the reaction liquid in the photocatalytic reaction pool. Sunlight irradiates PS, and under the sunlight condition, PS is activated to produce SO4· - and hydroxyl radicals (·OH), which preferentially oxidize small molecular organic pollutants. Most of the pollutants in the MBR treatment fluid are mineralized to produce CO2 and H2O, thereby reducing COD, BOD and NH4 + -N; PS refers to peroxydisulfate (usually expressed as S2O8²⁻), which is a chemical that can be used as an oxidant. When PS is activated by sunlight, it can produce two highly reactive free radicals: sulfate radicals (SO4·⁻) and hydroxyl radicals (·OH). These free radicals have extremely strong oxidizing ability and can effectively degrade organic pollutants in water, such as difficult-to-degrade substances in landfill leachate, converting them into more easily treatable small molecules or completely mineralizing them into carbon dioxide (CO2) and water (H2O), thereby achieving the purpose of deep water purification. Therefore, PS is a key reagent that can significantly improve the efficiency of sewage treatment after being activated by solar energy.

[0055] S5. With the irradiation of sunlight, the temperature in the photocatalytic reaction pool rises, providing activation energy to PS through heating, thereby generating SO4· - and ·OH, degrading pollutants in the MBR treatment liquid; S6. After a reaction cycle is completed, the reaction liquid in the photocatalytic reaction pool 1 is introduced into the acid-base neutralization pool 17 through the liquid outlet pipe 10 and the first valve 11. The pH value is adjusted before the discharge can meet the standards. S7. Sunlight irradiates the reaction liquid in the photocatalytic reaction pool through the light refraction mechanism composed of the solar concentrator 2 and the reflector 6. The temperature in the photocatalytic reaction pool rises. The PS is activated by the combination of sunlight and heating to produce SO4·- and ·OH, thereby reducing COD, BOD and NH4+-N.

[0056] Example 2 Further illustrate with reference to Example 1, Figure 1 The structure shown in the figure is for the treatment of landfill leachate. The process scheme includes pretreatment (including coagulation and sedimentation) + anaerobic USAB + MBR system (two-stage A / O + ultrafiltration UF) + deep treatment (solar photocatalytic reaction + acid-base neutralization); the anaerobic residence time is more than 8 days, the A / O system adopts jet aeration, the first-level A / O residence time is 12 days, the second-level A / O residence time is more than 2.5 days, and the solar photocatalytic reaction residence time is more than 3 days.

[0057] As shown in Table 1, after pretreatment + anaerobic USAB + MBR system, the COD Cr =350.0~450.0 mg / L, BOD5=22.2 mg / L, NH4 + -N=65.0~85.0 mg / L.

[0058] Table 1 Pollution concentration of landfill leachate raw water and MBR effluent

[0059] Example 3 Further illustrate with reference to Example 1, Figure 1-10 The structure shown in the figure is tested under different sunlight intensities by relying on the sunlight stabilization device and temperature measuring equipment. The test was conducted in Nanjing during the autumn, winter and spring periods from 8:00 to 16:00, with the near-ground sunlight intensity ranging from 1200 to 1700 μw / cm 3- The temperature in the photocatalytic reaction pool was maintained at 30-55 °C. In this experiment, 1600 μw / cm 3- and 45 ℃ as the reaction conditions in autumn, winter and spring. In this experiment, the period of 9:00-17:00 in summer in Nanjing was used, and the near-ground solar intensity was 1270-2500 μw / cm 3- The temperature in the photocatalytic reaction pool was maintained at 45-70°C. In this experiment, 2400 μw / cm 3- and 65 ℃ are the reaction conditions in summer.

[0060] Example 4 Further illustrate with reference to Example 1, Figure 5-7 For the structure shown in the figure, when 2kg, 4kg, and 8kg of PS were added, the reaction conditions were 2400 μw / cm 3- and 65 ℃, after 56 hours of reaction, COD, chromaticity and NH4 + -N was degraded from 385mg / L, 490PCU and 68mg / L to 101mg / L, 7PCU and 0.7mg / L respectively. 8kg of PS was the best dosage.

[0061] Example 5 Further illustrate with reference to Example 1, Figure 8-10 Structure shown, but reaction conditions were changed to 0 μw / cm 3- and 45℃, 0 μw / cm 3- and 65°C, 1600 μw / cm 3- and 45°C, 2400 μw / cm 3-and 65 ℃, the dosage of PS is 8kg. As shown in the figure, 2400 μw / cm 3- When the reaction conditions were 65 ℃, the COD, chromaticity and NH4 + -N degradation rate is the highest. Summer is the best reaction condition, and solar light intensity and reaction temperature have a significant effect on COD, chromaticity and NH4 + -N removal rate is positively correlated, and the solar photocatalytic device can effectively improve the removal of pollutants in landfill leachate.

[0062] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A device for photocatalytic deep treatment of landfill leachate, characterized by: The bioreactor (20) is connected to the liquid inlet pipe (9) of the photocatalytic reaction pool (1), and the liquid outlet pipe (10) of the photocatalytic reaction pool (1) is connected to the acid-base neutralization pool (17); The top opening of the photocatalytic reaction pool (1) is provided with a bracket (3), the upper surface of the bracket (3) is flatly paved with a plurality of solar concentrators (2), the bottom of the photocatalytic reaction pool (1) is paved with a plurality of reflectors (6), and a dosing pipe (4) and a water adding pipe are also provided inside the photocatalytic reaction pool (1), and a plurality of nozzles are provided on the dosing pipe (4); A plurality of stirrers (5) are provided at the bottom of the photocatalytic reaction pool (1) or at one side of the bottom.

2. According to claim 1, a device for photocatalytic deep treatment of landfill leachate is characterized by: A dosing pipe (7) is provided on one side of the photocatalytic reaction pool (1), and the dosing pipe (7) is connected to the dosing pipe (4) via a third valve (8).

3. The device for photocatalytic deep treatment of landfill leachate according to claim 2 is characterized by: The mixing chamber (23) is connected to the dosing pipe (7) via the dosing pump (22); The mixing chamber (23) is used to mix water and medicine.

4. The device for photocatalytic deep treatment of landfill leachate according to claim 1 is characterized by: The photocatalytic reaction pool (1) is also provided with a sunlight introduction system (13), and a light guide strip (15) is provided on the inner side wall or the bottom of the photocatalytic reaction pool (1), and the sunlight introduction system (13) is connected to the light guide strip (15) via an optical fiber (14).

5. The device for photocatalytic deep treatment of landfill leachate according to claim 1 is characterized by: The photocatalytic reaction pool (1) comprises an outer wall (101) and an inner wall (103), and a thermal insulation layer (102) is provided between the outer wall (101) and the inner wall (103).

6. The device for photocatalytic deep treatment of landfill leachate according to claim 1 is characterized by: A second pump body (21) is provided inside the bioreactor (20); the second pump body (21) is in communication with a liquid inlet pipe (9); and a second valve (12) is provided on the liquid inlet pipe (9).

7. The device for photocatalytic deep treatment of landfill leachate according to claim 1 is characterized by: A first pump body (16) is provided at the bottom of the photocatalytic reaction pool (1); the first pump body (16) is in communication with a liquid outlet pipe (10); and a first valve (11) is provided on the liquid outlet pipe (10).

8. The device for photocatalytic deep treatment of landfill leachate according to claim 1 is characterized by: The liquid outlet pipe (10) is connected to the bottom of the acid-base neutralization tank (17), and a rotatable stirring scraper plate (18) is provided inside the acid-base neutralization tank (17).

9. The device for photocatalytic deep treatment of landfill leachate according to claim 8 is characterized by: The bottom of the acid-base neutralization tank (17) is connected to the sludge tank (19).

10. A cleaning method for a device for photocatalytic deep treatment of landfill leachate according to any one of claims 1 to 9, characterized in that: The method includes: S1, 1 t-3 t of landfill leachate MBR treated liquid is introduced from the MBR into the photocatalytic reaction pool (1) through the liquid inlet pipe (9) and the second valve (12). At this time, the photocatalytic reaction pool (1) is used as a regulating pool to collect the landfill leachate MBR treated liquid, adopting the three-in-one standby method; S2, synchronously start the dosing pump (22), add 2kg-8kg of PS into the photocatalytic reaction tank (1) through the dosing pipe (4), and contact with the landfill leachate MBR treatment liquid; S3, synchronously start the agitator (5) at the bottom of the reaction tank to evenly mix the landfill leachate MBR treatment liquid and the reagent; S4, the sunlight passes through the light refraction mechanism composed of the solar concentrator (2) and the reflector (6), and at the same time the sunlight introduction system (13) introduces the sunlight into the photocatalytic reaction pool (1); Irradiate the reaction liquid in the photocatalytic reaction pool. Sunlight irradiates PS, and under the sunlight condition, PS is activated to produce SO4· - and hydroxyl radicals (·OH), which preferentially oxidize small molecular organic pollutants. Most of the pollutants in the MBR treatment fluid are mineralized to produce CO2 and H2O, thereby reducing COD, BOD and NH4 + -N; S5. With the irradiation of sunlight, the temperature in the photocatalytic reaction pool rises, providing activation energy to PS through heating, thereby generating SO4· - and ·OH, degrading pollutants in the MBR treatment liquid; S6. After a reaction cycle is completed, the reaction liquid in the photocatalytic reaction pool (1) is introduced into the acid-base neutralization pool (17) through the liquid outlet pipe (10) and the first valve (11), and the pH value is adjusted before the liquid can be discharged in compliance with the standards; S7. Sunlight passes through a light refraction mechanism composed of a solar concentrator (2) and a reflector (6) to irradiate the reaction liquid in the photocatalytic reaction pool. The temperature in the photocatalytic reaction pool rises, and the PS is activated to produce SO4· - and ·OH, thereby reducing COD, BOD and NH4 + -N.

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