Advanced oxidation method for treating garbage membrane concentrated solution

Abstract

The invention provides an advanced oxidation method for treating a garbage membrane concentrated solution, which comprises the following steps: (1) adding quick lime into a garbage leachate concentrated solution, and then adding sodium carbonate for softening to obtain a softened solution; (2) adding a flocculating agent into the softened liquid, carrying out flocculent precipitation to obtain a flocculated liquid, and filtering the flocculated liquid to obtain a flocculated clear liquid; (3) adding hydrogen peroxide into the flocculated clear liquid, enabling the flocculated clear liquid to flow through three-dimensional electro-catalysis equipment from bottom to top, carrying out advanced oxidation to obtain oxidized liquid, and discharging effluent; the three-dimensional electro-catalysis equipment is a three-dimensional electrode reaction system formed by coupling a polar plate material with a catalyst, and the catalyst is a catalyst in which an active component is loaded by an alumina carrier. According to the treatment method disclosed by the invention, the leachate concentrated solution of the refuse landfill can be well treated, so that the removal rate of COD (Chemical Oxygen Demand) in the landfill leachate concentrated solution reaches 94% or above, the removal rate of total nitrogen reaches 93% or above, the hardness removal rate reaches 88% or above, and the removal rate of heavy metal ions reaches 94% or above.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment and purification, and specifically relates to an advanced oxidation method for treating garbage membrane concentrated liquid. Background Art

[0002] As the requirements for urban landfill leachate treatment become higher and higher, many users have adopted a combination of biochemical filtration membrane processes. However, more than 99% of users use the traditional nanofiltration-reverse osmosis (NF / RO) double membrane method to treat landfill leachate. The reason for many people choosing this method is that the initial cost is low and the effluent meets the standards. However, in the later stage, the membrane is prone to clogging, the system has poor stability and is not impact-resistant, resulting in the accumulation of toxic and harmful substances in the cycle. The system collapses in the later stage and cannot continue to operate. However, the most important thing is that a batch of concentrated liquid is inevitably produced while meeting the emission standards. Landfill leachate concentrate is the concentrated liquid produced after the landfill leachate is treated using a membrane treatment process. Compared with landfill leachate, the pollutant concentration of the concentrate is several times higher than that of the leachate, making it more difficult to treat.

[0003] The volume of membrane concentrate produced by nanofiltration membrane process accounts for 20%-50% of the total original leachate, and the transportation cost of the concentrate is high. From the perspective of pollutants, the concentrate of leachate cannot be used as a nutrient source. Moreover, the main component of COD in the concentrate is difficult-to-degrade organic matter, which generally depends on the scale of the landfill. The COD concentration of the concentrate between 1000-5000 mg / L is difficult to participate in microbial reactions as a nutrient source. In addition, the total nitrogen content of the concentrate is very high, and the chromaticity of the concentrate is between 500 and 5000 times that of the original leachate, and it smells extremely bad. In addition to the above-mentioned pollutants, there is also the most important salinity. The extremely high salt content of the concentrate has become a major problem in the treatment of leachate.

[0004] At present, the main treatment methods for landfill leachate membrane concentrate are: recharge, membrane distillation, evaporation, and advanced oxidation. Recharge, the so-called recharge is to regard the landfill itself as a biological filter bed, and the concentrate is injected into the upper end of the pile, passing through the landfill layer, and the microorganisms in the garbage will degrade the organic pollutants in the concentrate. Experiments show that recharge treatment of concentrate is technically feasible, and recharge can effectively remove COD, ammonia nitrogen, and total nitrogen. Hydraulic load has a significant effect on the removal of COD by recharge of concentrate. However, recharge increases the pollution of groundwater and increases the water content of the landfill layer. Direct recharge of concentrate may also lead to an increase in the salt content of the landfill. Membrane distillation, membrane distillation is a membrane separation process that uses a hydrophobic microporous membrane to use the vapor pressure difference on both sides of the membrane as the driving force for mass transfer. The water-transporting microporous membrane will separate the aqueous solution according to the temperature. According to the hydrophobicity of the membrane, the aqueous solution on both sides cannot pass through the membrane pores to enter the other side, but the water vapor pressure of the warm side aqueous solution and the membrane interface is higher than that of the cold side. The water vapor will pass through the membrane pores from the warm side to the cold side to achieve condensation. Vacuum membrane distillation (VMD) is a new type of membrane separation process that combines membrane technology with traditional distillation technology. It has the advantages of low operating temperature, simple equipment, 100% interception rate for volatiles such as inorganic salts and macromolecules, and can achieve the treatment of high-concentration solutions. However, there is no report on the use of membrane distillation for landfill leachate nanofiltration membrane concentrate. Evaporation, evaporation is increasingly used in the treatment of landfill leachate and landfill leachate nanofiltration membrane concentrate. Currently, the more commonly used are immersion combustion, negative pressure evaporation, and mechanical compression evaporation. The experimental results show that under acidic conditions, the higher the pH of the original solution, the higher the concentration of ammonia nitrogen in the condensate, and the lower the COD. However, the evaporation of organic matter is in the early stage of evaporation, while the evaporation of ammonia nitrogen is in the later stage. Advanced oxidation, advanced ozone catalytic oxidation can effectively destroy the macromolecular organic matter containing benzene rings and non-ferrous groups in the landfill leachate nanofiltration membrane concentrate, and the effect of improving the biodegradability of the concentrate is the best. Process advantages: ① Fully quantitative, membrane-free treatment, no concentrated solution process, no concentrated solution, no secondary pollution. ②Automated management, low operating costs. ③Fast response speed, high system stability, and small footprint.

[0005] The advanced oxidation effect in the existing technology is not ideal and cannot meet the increasingly high processing requirements. Summary of the invention

[0006] The purpose of the present invention is to provide a method for treating garbage membrane concentrate by an advanced oxidation process.

[0007] In order to achieve the above object, the present invention provides the following technical solutions: An advanced oxidation method for treating garbage membrane concentrate comprises the following steps: (1) adding quicklime to the landfill leachate concentrate, and then adding sodium carbonate to soften it to obtain a softened liquid; (2) adding a flocculant to the softening liquid to perform flocculation and precipitation to obtain a flocculated liquid, and filtering the flocculated liquid to obtain a flocculated clear liquid; (3) adding hydrogen peroxide to the flocculated clear liquid, and then flowing it through a three-dimensional electrocatalytic device from bottom to top for advanced oxidation to obtain an oxidized liquid, which is discharged as effluent; the three-dimensional electrocatalytic device is a three-dimensional electrode reaction system formed by coupling a plate material with a catalyst, and the catalyst is a catalyst with an active ingredient supported by an alumina carrier; The preparation method of the catalyst is: S1: illite and water are mixed at a mass ratio of 1:10-15, the pH value is adjusted to 3-5, and then the mixture is debonded at 60-80°C for 10-15h, and the debonded mixture is aged at 70-90°C for 20-30h to obtain alumina sol; S2: mixing alumina sol and alumina in a mass ratio of 1-4:1, drying the mixture at 80-100° C. for 12-15 hours, and then calcining the mixture at 500-600° C. for 15-20 hours to obtain an alumina carrier; S3: The alumina carrier is mixed and impregnated with a mixed solution containing 1 mol / L iron oxide, 1.2-1.5 mol / L copper oxide and 0.4-0.7 mol / L cuprous oxide according to the equal volume method, dried at 110-130°C for 12-20 hours, calcined in air at 600-700°C for 12-24 hours, and ceramsite is added to obtain a catalyst.

[0008] Furthermore, the flocculant is a mixture of polyaluminium ferric chloride, polyaluminium chloride and polyferric chloride in a mass ratio of 1:1.3-1.6:0.4-0.8.

[0009] Furthermore, the amount of flocculant added to the landfill leachate concentrate is 0.2-0.5 kg / m 3 .

[0010] Furthermore, the mass ratio of the hydrogen peroxide to the COD in the flocculation liquid is 0.5-1:1.

[0011] Furthermore, the residence time of the flocculated clear liquid in the fluidized bed is 50 min-80 min.

[0012] Furthermore, the temperature in the fluidized bed is 40-60°C.

[0013] Furthermore, the catalyst particle size is 10 μm-50 μm.

[0014] Furthermore, the pH value of the flocculation clear liquid ranges from 5 to 10.

[0015] Furthermore, the fluidized bed reactor is made of transparent organic glass, and the entire fluidized bed reactor is placed under ultraviolet light.

[0016] Furthermore, the mass ratio of the landfill leachate concentrate to quicklime is 600-800:1, and the molar ratio of sodium carbonate to quicklime is 1-3:1.

[0017] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: the treatment method of the present invention achieves efficient removal of various pollutants in the landfill leachate concentrate by combining the application of advanced oxidation method with catalyst through multiple mechanisms such as oxidation, decomposition, coprecipitation and adsorption. Using alumina loaded active substances as catalyst can significantly improve the treatment effect. Alumina ( ) has a high specific surface area, which allows it to carry a large amount of active substances, increasing the chances of contact between the catalyst and the reactants, thereby improving the catalytic efficiency. Alumina exhibits good chemical stability over a wide pH range and at high temperatures, which means that it can maintain its structure and catalytic activity even under harsh treatment conditions, ensuring the long-term effectiveness of the catalyst. The porosity of alumina enables it to provide a three-dimensional network structure for the active substances, which helps to disperse the active components and prevent them from agglomerating, while providing sufficient pores for reactants and products to enter and exit, improving the reaction kinetics. It can treat the leachate concentrate from the landfill very well, so that the COD removal rate in the leachate concentrate reaches more than 94%, the total nitrogen removal rate reaches more than 93%, the hardness removal rate reaches more than 88%, and the heavy metal ion removal rate reaches more than 94%.

[0018] The three-dimensional electrocatalytic equipment system used in the present invention has a good mass transfer effect, and can remove refractory organic matter and inorganic salts in wastewater through reactions such as coagulation, chemical oxidation-reduction, and micro-electrolysis. During the treatment process, electron transfer is only carried out between the electrode and the wastewater components, generating oxidants and reductants such as hydroxyl radicals, without the need to add liquid medicine, thus saving energy, reducing consumption and carbon, and having low operating costs. The removal rates of COD, ammonia nitrogen, total nitrogen, and total phosphorus are high, and the decolorization effect is good. The operation is simple and flexible, and the reaction conditions can be adjusted at any time by changing the voltage and current, with good controllability. It occupies a small area and has a short construction period. The amount of sludge is small and does not scale. At the same time, it can be combined with other technologies to reduce costs and improve treatment effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the electrode plate arrangement of a three-dimensional electrocatalytic device. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1 See also Figure 1 This embodiment provides an advanced oxidation method for treating garbage membrane concentrate, comprising the following steps: (1) adding quicklime to the landfill leachate concentrate, and then adding sodium carbonate to soften it to obtain a softened liquid; (2) adding a flocculant to the softening liquid to perform flocculation and precipitation to obtain a flocculated liquid, and filtering the flocculated liquid to obtain a flocculated clear liquid; (3) adding hydrogen peroxide to the flocculated clear liquid, and then flowing it through a three-dimensional electrocatalytic device from bottom to top for advanced oxidation to obtain an oxidized liquid, which is discharged as effluent; the three-dimensional electrocatalytic device is a three-dimensional electrode reaction system formed by coupling a plate material with a catalyst, and the catalyst is a catalyst with an active ingredient supported by an alumina carrier; The preparation method of the catalyst is: S1: illite and water in a mass ratio of 1:12 were mixed, the pH value was adjusted to 4, and then the mixture was debonded at 70°C for 12 hours. The debonded mixture was aged at 80°C for 25 hours to obtain an alumina sol; S2: mixing alumina sol and alumina in a mass ratio of 3:1, drying the mixture at 90°C for 14 hours, and then calcining the mixture at 550°C for 18 hours to obtain an alumina carrier; S3: The alumina carrier is mixed and impregnated with a mixed solution containing 1 mol / L iron oxide, 1.4 mol / L copper oxide and 0.6 mol / L cuprous oxide according to the equal volume method, dried at 120°C for 15 hours, calcined in air at 650°C for 17 hours, and ceramsite is added to obtain a catalyst.

[0022] The flocculant is a mixture of polyaluminium ferric chloride, polyaluminium chloride and polyferric chloride in a mass ratio of 1:1.5:0.6.

[0023] The amount of flocculant added to the landfill leachate concentrate is 0.4 kg / m 3 .

[0024] The mass ratio of the hydrogen peroxide to the COD in the flocculation liquid is 0.7:1.

[0025] The residence time of the flocculated clear liquid in the fluidized bed is 60 min.

[0026] The temperature in the fluidized bed was 50°C.

[0027] The pH value of the flocculated liquid was 7.

[0028] The fluidized bed reactor is made of transparent organic glass, and the entire fluidized bed reactor is placed under ultraviolet light.

[0029] The mass ratio of landfill leachate concentrate to quicklime is 700:1, and the molar ratio of sodium carbonate to quicklime is 2:1.

[0030] Example 2 This embodiment provides an advanced oxidation process for treating garbage film concentrate, comprising the following steps: (1) adding quicklime to the landfill leachate concentrate, and then adding sodium carbonate to soften it to obtain a softened liquid; (2) adding a flocculant to the softening liquid to perform flocculation and precipitation to obtain a flocculated liquid, and filtering the flocculated liquid to obtain a flocculated clear liquid; (3) adding hydrogen peroxide to the flocculated clear liquid, and then flowing it through a three-dimensional electrocatalytic device from bottom to top for advanced oxidation to obtain an oxidized liquid, which is discharged as effluent; the three-dimensional electrocatalytic device is a three-dimensional electrode reaction system formed by coupling a plate material with a catalyst, and the catalyst is a catalyst with an active ingredient supported by an alumina carrier; The preparation method of the catalyst is: S1: illite and water in a mass ratio of 1:10 were mixed, the pH value was adjusted to 3, and then the mixture was debonded at 60°C for 10 hours, and the debonded mixture was aged at 70°C for 20 hours to obtain alumina sol; S2: mixing alumina sol and alumina in a mass ratio of 1:1, drying the mixture at 80°C for 12 hours, and then calcining the mixture at 500°C for 15 hours to obtain an alumina carrier; S3: The alumina carrier is mixed and impregnated with a mixed solution containing 1 mol / L iron oxide, 1.2 mol / L copper oxide and 0.4 mol / L cuprous oxide according to the equal volume method, dried at 110°C for 12 hours, calcined in air at 600°C for 12 hours, and ceramsite is added to obtain a catalyst.

[0031] The flocculant is a mixture of polyaluminium ferric chloride, polyaluminium chloride and polyferric chloride in a mass ratio of 1:1.3:0.4.

[0032] The amount of flocculant added to the landfill leachate concentrate is 0.2 kg / m 3 .

[0033] The mass ratio of the hydrogen peroxide to the COD in the flocculation liquid is 0.5:1.

[0034] The residence time of the flocculated liquid in the fluidized bed is 50 min.

[0035] The temperature in the fluidized bed was 40°C.

[0036] The pH value of the flocculated liquid is in the range of 5.

[0037] The fluidized bed reactor is made of transparent organic glass, and the entire fluidized bed reactor is placed under ultraviolet light.

[0038] The mass ratio of landfill leachate concentrate to quicklime is 600:1, and the molar ratio of sodium carbonate to quicklime is 1:1.

[0039] Example 3 This embodiment provides an advanced oxidation process for treating garbage film concentrate, comprising the following steps: (1) adding quicklime to the landfill leachate concentrate, and then adding sodium carbonate to soften it to obtain a softened liquid; (2) adding a flocculant to the softening liquid to perform flocculation and precipitation to obtain a flocculated liquid, and filtering the flocculated liquid to obtain a flocculated clear liquid; (3) adding hydrogen peroxide to the flocculated clear liquid, and then flowing it through a three-dimensional electrocatalytic device from bottom to top for advanced oxidation to obtain an oxidized liquid, which is discharged as effluent; the three-dimensional electrocatalytic device is a three-dimensional electrode reaction system formed by coupling a plate material with a catalyst, and the catalyst is a catalyst with an active ingredient supported by an alumina carrier; The preparation method of the catalyst is: S1: illite and water in a mass ratio of 1:15 were mixed, the pH value was adjusted to 5, and then the mixture was debonded at 80°C for 15 hours, and the debonded mixture was aged at 90°C for 30 hours to obtain an alumina sol; S2: mixing alumina sol and alumina in a mass ratio of 4:1, drying the mixture at 100°C for 15 hours, and then calcining the mixture at 600°C for 20 hours to obtain an alumina carrier; S3: The alumina carrier is impregnated with a mixed solution containing 1 mol / L iron oxide, 1.5 mol / L copper oxide and 0.7 mol / L cuprous oxide by an equal volume method, dried at 130°C for 20 hours, calcined in air at 700°C for 24 hours, and ceramsite is added to obtain a catalyst.

[0040] The flocculant is a mixture of polyaluminium ferric chloride, polyaluminium chloride and polyferric chloride in a mass ratio of 1: 1.6: 0.8.

[0041] The amount of flocculant added to the landfill leachate concentrate is 0.5 kg / m 3 .

[0042] The mass ratio of the hydrogen peroxide to the COD in the flocculation liquid is 1:1.

[0043] The residence time of the flocculated liquid in the fluidized bed is 80 min.

[0044] The temperature in the fluidized bed was 60°C.

[0045] The pH value of the flocculated liquid is in the range of 10.

[0046] The fluidized bed reactor is made of transparent organic glass, and the entire fluidized bed reactor is placed under ultraviolet light.

[0047] The mass ratio of landfill leachate concentrate to quicklime is 800:1, and the molar ratio of sodium carbonate to quicklime is 3:1.

[0048] Comparative Example 1 The difference between this comparative example and Example 1 is that the flocculant is a mixture of polyaluminium ferric chloride, polyaluminium chloride and polyferric chloride in a mass ratio of 1:1:1.

[0049] An advanced oxidation method for treating garbage membrane concentrate comprises the following steps: (1) adding quicklime to the landfill leachate concentrate, and then adding sodium carbonate to soften it to obtain a softened liquid; (2) adding a flocculant to the softening liquid to perform flocculation and precipitation to obtain a flocculated liquid, and filtering the flocculated liquid to obtain a flocculated clear liquid; (3) adding hydrogen peroxide to the flocculated clear liquid, and then flowing it through a three-dimensional electrocatalytic device from bottom to top for advanced oxidation to obtain an oxidized liquid, which is discharged as effluent; the three-dimensional electrocatalytic device is a three-dimensional electrode reaction system formed by coupling a plate material with a catalyst, and the catalyst is a catalyst with an active ingredient supported by an alumina carrier; The preparation method of the catalyst is: S1: illite and water in a mass ratio of 1:12 were mixed, the pH value was adjusted to 4, and then the mixture was debonded at 70°C for 12 hours. The debonded mixture was aged at 80°C for 25 hours to obtain an alumina sol; S2: mixing alumina sol and alumina in a mass ratio of 3:1, drying the mixture at 90°C for 14 hours, and then calcining the mixture at 550°C for 18 hours to obtain an alumina carrier; S3: The alumina carrier is mixed and impregnated with a mixed solution containing 1 mol / L iron oxide, 1.4 mol / L copper oxide and 0.6 mol / L cuprous oxide according to the equal volume method, dried at 120°C for 15 hours, calcined in air at 650°C for 17 hours, and ceramsite is added to obtain a catalyst.

[0050] The flocculant is a mixture of polyaluminium ferric chloride, polyaluminium chloride and polyferric chloride in a mass ratio of 1:1:1.

[0051] The amount of flocculant added to the landfill leachate concentrate is 0.4 kg / m 3 .

[0052] The mass ratio of the hydrogen peroxide to the COD in the flocculation liquid is 0.7:1.

[0053] The residence time of the flocculated clear liquid in the fluidized bed is 60 min.

[0054] The temperature in the fluidized bed was 50°C.

[0055] The pH value of the flocculated liquid was 7.

[0056] The fluidized bed reactor is made of transparent organic glass, and the entire fluidized bed reactor is placed under ultraviolet light.

[0057] The mass ratio of landfill leachate concentrate to quicklime is 700:1, and the molar ratio of sodium carbonate to quicklime is 2:1.

[0058] Comparative Example 2 The difference between this comparative example and Example 1 is that the alumina carrier and 3 mol / L iron oxide solution are mixed and impregnated according to the equal volume method.

[0059] An advanced oxidation method for treating garbage membrane concentrate comprises the following steps: (1) adding quicklime to the landfill leachate concentrate, and then adding sodium carbonate to soften it to obtain a softened liquid; (2) adding a flocculant to the softening liquid to perform flocculation and precipitation to obtain a flocculated liquid, and filtering the flocculated liquid to obtain a flocculated clear liquid; (3) adding hydrogen peroxide to the flocculated clear liquid, and then flowing it through a three-dimensional electrocatalytic device from bottom to top for advanced oxidation to obtain an oxidized liquid, which is discharged as effluent; the three-dimensional electrocatalytic device is a three-dimensional electrode reaction system formed by coupling a plate material with a catalyst, and the catalyst is a catalyst with an active ingredient supported by an alumina carrier; The preparation method of the catalyst is: S1: illite and water in a mass ratio of 1:12 were mixed, the pH value was adjusted to 4, and then the mixture was debonded at 70°C for 12 hours. The debonded mixture was aged at 80°C for 25 hours to obtain an alumina sol; S2: mixing alumina sol and alumina in a mass ratio of 3:1, drying the mixture at 90°C for 14 hours, and then calcining the mixture at 550°C for 18 hours to obtain an alumina carrier; S3: The alumina carrier and 3 mol / L iron oxide solution were mixed and impregnated by an equal volume method, dried at 120° C. for 15 hours, calcined in air at 650° C. for 17 hours, and ceramsite was added to obtain a catalyst.

[0060] The flocculant is a mixture of polyaluminium ferric chloride, polyaluminium chloride and polyferric chloride in a mass ratio of 1:1.5:0.6.

[0061] The amount of flocculant added to the landfill leachate concentrate is 0.4 kg / m 3 .

[0062] The mass ratio of the hydrogen peroxide to the COD in the flocculation liquid is 0.7:1.

[0063] The residence time of the flocculated clear liquid in the fluidized bed is 60 min.

[0064] The temperature in the fluidized bed was 50°C.

[0065] The pH value of the flocculated liquid was 7.

[0066] The fluidized bed reactor is made of transparent organic glass, and the entire fluidized bed reactor is placed under ultraviolet light.

[0067] The mass ratio of landfill leachate concentrate to quicklime is 700:1, and the molar ratio of sodium carbonate to quicklime is 2:1.

[0068] Comparative Example 3 The difference between this comparative example and Example 1 is that the alumina sol and alumina in a mass ratio of 0.2:1 are mixed and then dried at 90° C. for 14 hours.

[0069] An advanced oxidation method for treating garbage membrane concentrate comprises the following steps: (1) adding quicklime to the landfill leachate concentrate, and then adding sodium carbonate to soften it to obtain a softened liquid; (2) adding a flocculant to the softening liquid to perform flocculation and precipitation to obtain a flocculated liquid, and filtering the flocculated liquid to obtain a flocculated clear liquid; (3) adding hydrogen peroxide to the flocculated clear liquid, and then flowing it through a three-dimensional electrocatalytic device from bottom to top for advanced oxidation to obtain an oxidized liquid, which is discharged as effluent; the three-dimensional electrocatalytic device is a three-dimensional electrode reaction system formed by coupling a plate material with a catalyst, and the catalyst is a catalyst with an active ingredient supported by an alumina carrier; The preparation method of the catalyst is: S1: illite and water in a mass ratio of 1:12 were mixed, the pH value was adjusted to 4, and then the mixture was debonded at 70°C for 12 hours. The debonded mixture was aged at 80°C for 25 hours to obtain an alumina sol; S2: mixing alumina sol and alumina in a mass ratio of 0.2:1, drying the mixture at 90° C. for 14 hours, and then calcining the mixture at 550° C. for 18 hours to obtain an alumina carrier; S3: The alumina carrier is mixed and impregnated with a mixed solution containing 1 mol / L iron oxide, 1.4 mol / L copper oxide and 0.6 mol / L cuprous oxide according to the equal volume method, dried at 120°C for 15 hours, calcined in air at 650°C for 17 hours, and ceramsite is added to obtain a catalyst.

[0070] The flocculant is a mixture of polyaluminium ferric chloride, polyaluminium chloride and polyferric chloride in a mass ratio of 1:1.5:0.6.

[0071] The amount of flocculant added to the landfill leachate concentrate is 0.4 kg / m 3 .

[0072] The mass ratio of the hydrogen peroxide to the COD in the flocculation liquid is 0.7:1.

[0073] The residence time of the flocculated clear liquid in the fluidized bed is 60 min.

[0074] The temperature in the fluidized bed was 50°C.

[0075] The pH value of the flocculated liquid was 7.

[0076] The fluidized bed reactor is made of transparent organic glass, and the entire fluidized bed reactor is placed under ultraviolet light.

[0077] The mass ratio of landfill leachate concentrate to quicklime is 700:1, and the molar ratio of sodium carbonate to quicklime is 2:1.

[0078] Comparative Example 4 The difference between this comparative example and Example 1 is that the alumina carrier is mixed and impregnated with a mixed solution containing 1 mol / L ferric oxide, 1 mol / L copper oxide and 1 mol / L cuprous oxide according to an equal volume method.

[0079] An advanced oxidation method for treating garbage membrane concentrate comprises the following steps: (1) adding quicklime to the landfill leachate concentrate, and then adding sodium carbonate to soften it to obtain a softened liquid; (2) adding a flocculant to the softening liquid to perform flocculation and precipitation to obtain a flocculated liquid, and filtering the flocculated liquid to obtain a flocculated clear liquid; (3) adding hydrogen peroxide to the flocculated clear liquid, and then flowing it through a three-dimensional electrocatalytic device from bottom to top for advanced oxidation to obtain an oxidized liquid, which is discharged as effluent; the three-dimensional electrocatalytic device is a three-dimensional electrode reaction system formed by coupling a plate material with a catalyst, and the catalyst is a catalyst with an active ingredient supported by an alumina carrier; The preparation method of the catalyst is: S1: illite and water in a mass ratio of 1:12 were mixed, the pH value was adjusted to 4, and then the mixture was debonded at 70°C for 12 hours. The debonded mixture was aged at 80°C for 25 hours to obtain an alumina sol; S2: mixing alumina sol and alumina in a mass ratio of 3:1, drying the mixture at 90°C for 14 hours, and then calcining the mixture at 550°C for 18 hours to obtain an alumina carrier; S3: The alumina carrier is mixed and impregnated with a mixed solution containing 1 mol / L iron oxide, 1 mol / L copper oxide and 1 mol / L cuprous oxide according to the equal volume method, dried at 120°C for 15 hours, calcined in air at 650°C for 17 hours, and ceramsite is added to obtain a catalyst.

[0080] The flocculant is a mixture of polyaluminium ferric chloride, polyaluminium chloride and polyferric chloride in a mass ratio of 1:1.5:0.6.

[0081] The amount of flocculant added to the landfill leachate concentrate is 0.4 kg / m 3 .

[0082] The mass ratio of the hydrogen peroxide to the COD in the flocculation liquid is 0.7:1.

[0083] The residence time of the flocculated clear liquid in the fluidized bed is 60 min.

[0084] The temperature in the fluidized bed was 50°C.

[0085] The pH value of the flocculated liquid was 7.

[0086] The fluidized bed reactor is made of transparent organic glass, and the entire fluidized bed reactor is placed under ultraviolet light.

[0087] The mass ratio of landfill leachate concentrate to quicklime is 700:1, and the molar ratio of sodium carbonate to quicklime is 2:1.

[0088] Performance Testing The methods of Examples 1-3 and Comparative Examples 1-4 were used to treat the garbage membrane concentrate from a certain place, and the COD removal rate, total nitrogen removal rate, hardness removal rate and metal ion removal rate were calculated. The results are shown in Table 1.

[0089] Table 1 Performance test results

[0090] It can be seen from the above performance test results that Examples 1-3 have the best treatment effects. However, since the comparative examples do not adopt the necessary technical solutions, their corresponding performance tests are significantly worse than those of the examples. The above experimental results further prove the importance of the technical solutions defined in the present invention for its technical effects.

[0091] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An advanced oxidation process for treating garbage membrane concentrate, characterized in that: The following steps are involved: (1) adding quicklime to the landfill leachate concentrate, and then adding sodium carbonate to soften it to obtain a softened liquid; (2) adding a flocculant to the softening liquid to perform flocculation and precipitation to obtain a flocculated liquid, and filtering the flocculated liquid to obtain a flocculated clear liquid; (3) adding hydrogen peroxide to the flocculated clear liquid, and then flowing it through a three-dimensional electrocatalytic device from bottom to top for advanced oxidation to obtain an oxidized liquid, which is discharged as effluent; the three-dimensional electrocatalytic device is a three-dimensional electrode reaction system formed by coupling a plate material with a catalyst, and the catalyst is a catalyst with an active ingredient supported by an alumina carrier; The preparation method of the catalyst is: S1: illite and water are mixed at a mass ratio of 1:10-15, the pH value is adjusted to 3-5, and then the mixture is debonded at 60-80°C for 10-15h, and the debonded mixture is aged at 70-90°C for 20-30h to obtain alumina sol; S2: mixing alumina sol and alumina in a mass ratio of 1-4:1, drying the mixture at 80-100° C. for 12-15 hours, and then calcining the mixture at 500-600° C. for 15-20 hours to obtain an alumina carrier; S3: The alumina carrier is mixed and impregnated with a mixed solution containing 1 mol / L iron oxide, 1.2-1.5 mol / L copper oxide and 0.4-0.7 mol / L cuprous oxide according to the equal volume method, dried at 110-130°C for 12-20 hours, calcined in air at 600-700°C for 12-24 hours, and ceramsite is added to obtain a catalyst.

2. The method for treating garbage membrane concentrate by an advanced oxidation process according to claim 1, characterized in that: The flocculant is a mixture of polyaluminium ferric chloride, polyaluminium chloride and polyferric chloride in a mass ratio of 1:1.3-1.6:0.4-0.

8.

3. The method for treating garbage membrane concentrate by an advanced oxidation process according to claim 1, characterized in that: The amount of flocculant added to the landfill leachate concentrate is 0.2-0.5 kg / m 3 .

4. The method for treating garbage membrane concentrate by an advanced oxidation process according to claim 1, characterized in that: The mass ratio of the hydrogen peroxide to the COD in the flocculation liquid is 0.5-1:

1.

5. The method for treating garbage membrane concentrate by an advanced oxidation process according to claim 1, characterized in that: The residence time of the flocculated clear liquid in the fluidized bed is 50min-80min.

6. The method for treating garbage membrane concentrate by advanced oxidation process according to claim 1, characterized in that: The temperature in the fluidized bed is 40-60°C.

7. The method for treating garbage membrane concentrate by an advanced oxidation process according to claim 1, characterized in that: The catalyst particle size is 10 μm-50 μm.

8. The method for treating garbage membrane concentrate by an advanced oxidation process according to claim 1, characterized in that: The pH value of the flocculated liquid ranges from 5 to 10.

9. The method for treating garbage membrane concentrate by an advanced oxidation process according to claim 1, characterized in that: The fluidized bed reactor is made of transparent organic glass, and the entire fluidized bed reactor is placed under ultraviolet light.

10. The method for treating garbage membrane concentrate by an advanced oxidation process according to claim 1, characterized in that: The mass ratio of the landfill leachate concentrate to quicklime is 600-800:1, and the molar ratio of sodium carbonate to quicklime is 1-3:1.

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