A sulfur cycle multistage anaerobic device for treating landfill leachate

Abstract

A kind of sulfur cycle multistage anaerobic device for treating landfill leachate, it relates to municipal solid waste treatment technical field.To solve the existing primary leachate treatment, mainly aerobic treatment combined with chemical and physical treatment, aerobic treatment mechanism mainly consists of microorganism through aeration degradation of pollutants in leachate, but still insufficient to remove toxic pollutants in water, thereby leading to poor pollutant removal effect Problem.At least four box bodies are fixedly connected in turn two by two along the horizontal direction, and the inside top surface of each box body is provided with an anaerobic baffle, one side of the anaerobic baffle is provided with a baffle, the end surface of the baffle is fixedly connected with the inner wall of the box body, the top end gas outlet of each box body is provided with a gas outlet valve, the inside bottom end of the box body is provided with a heater and a temperature sensor, and the outside end surface of the outermost two box bodies is respectively provided with a liquid inlet, and an inlet valve is arranged on the liquid inlet. The utility model is suitable for effectively treating landfill leachate.

Description

Technical Field

[0001] This utility model relates to the field of urban waste treatment technology, specifically to a sulfur-circulating multi-stage anaerobic device for treating landfill leachate. Background Technology

[0002] Landfill leachate treatment is a crucial issue in urban solid waste management. With the rapid urbanization and rising living standards in my country, the amount of municipal solid waste generated continues to climb, exceeding 300 million tons in 2024. During the accumulation of this waste in landfills, the organic components combine with infiltrated rainwater through physical, chemical, and biological processes, resulting in leachate. Leachate may contain large amounts of organic pollutants, ammonia, suspended solids, heavy metals, inorganic salts, phenols, and phosphorus. The complexity of these characteristics makes leachate more difficult to treat. Without proper treatment and disposal, leachate can pollute surrounding soil, groundwater, or surface water. To reduce the negative environmental impact of leachate, various treatment technologies have been adopted. These technologies can be categorized into physical, chemical, and biological treatments. The characteristics of leachate determine the most suitable treatment method. The chemical composition of leachate varies significantly between different landfills. Existing methods for treating raw leachate mainly involve a combination of aerobic and chemical / physical treatment. The aerobic treatment mechanism primarily consists of microorganisms degrading pollutants in the leachate through aeration, but this is still insufficient to remove toxic pollutants from the water, resulting in poor pollutant removal efficiency. Utility Model Content

[0003] This invention addresses the problem that existing methods for treating primary leachate mainly involve aerobic treatment combined with chemical and physical processes. The aerobic treatment mechanism primarily consists of microorganisms degrading pollutants in the leachate through aeration, but this is still insufficient to remove toxic pollutants from the water, resulting in poor pollutant removal efficiency. Therefore, this invention proposes a sulfur-cycle multi-stage anaerobic device for treating landfill leachate.

[0004] This utility model discloses a sulfur-circulating multi-stage anaerobic device for treating landfill leachate, which comprises a baffle 1, a gas outlet valve 2, an anaerobic baffle 3, a heater 4, a temperature sensor 6, an inlet valve 8, and at least four chambers 9.

[0005] At least four boxes 9 are fixedly connected in pairs along the horizontal direction, and each box 9 has an anaerobic baffle 3 at one end of its internal top surface. A baffle 1 is provided on one side of the anaerobic baffle 3. The end face of the baffle 1 is fixedly connected to the inner wall of the box 9. A gas outlet valve 2 is provided at the top gas outlet of each box 9. A heater 4 and a temperature sensor 6 are provided at the bottom of the inside of the box 9. A liquid inlet is provided on the outer end face of the two outermost boxes 9, and an inlet valve 8 is provided on the liquid inlet.

[0006] Furthermore, the internal structures of the four boxes 9 are identical;

[0007] Furthermore, a sludge sampling port 5 is provided on the lower front of the box body 9;

[0008] Furthermore, the upper part of the back of the box 9 is provided with a supernatant sampling port 7;

[0009] Furthermore, the centerline of the baffle 1 is inclined at 45° to the axis of the box body 9;

[0010] Furthermore, each pair of adjacent boxes 9 has a communication opening on the upper part of their opposite end faces;

[0011] Furthermore, the four boxes 9 are internally interconnected;

[0012] Furthermore, the enclosure 9 is made of plexiglass;

[0013] Furthermore, in operation, the sulfur-circulating multi-stage anaerobic digester is a rectangular box consisting of four identical chambers 9, each with a volume of 7 liters, for a total working volume of 28 liters. Each chamber 9 is further divided by a 45° inclined baffle 1, creating a descending and ascending zone within each chamber 9. Liquid flows from one chamber 9 to another, passing through a 10 mm × 50 mm vent located approximately 23 mm from the upper side of each chamber 9. The vent is connected to a gas outlet valve 2 for collecting and removing harmful gases generated during the anaerobic process. The amount of harmful gases generated in each chamber 9 is monitored using an optical gas bubble meter. A heater 4 is installed at the bottom of each compartment to maintain the compartment temperature of the sulfur-circulating multi-stage anaerobic digester at 37 ± 0.5 °C; a temperature sensor 6 is installed in each compartment to ensure a constant operating temperature.

[0014] The aged landfill leachate is collected and transferred to a dedicated storage tank. Using the aforementioned multi-stage anaerobic digester with sulfur circulation, inlet valve 8, heater 4, and temperature sensor 6 are opened, while supernatant sampling port 7, sludge sampling port 5, and gas outlet valve 2 are simultaneously closed. The wastewater to be treated enters the multi-stage anaerobic digester through inlet valve 8. By adding anaerobic biological agents and adjusting aeration time, dissolved oxygen content, and oxidation-reduction potential, microorganisms adhere to the anaerobic sludge, forming an effective sulfur circulation system and further improving the biological removal capacity of the landfill leachate. The added electron acceptors are mainly sodium sulfide and sodium sulfate, with a mass ratio of sodium sulfide to magnesium sulfate of 1:2. The added biological compound agent consists of Thiobacillus denitrificans, sulfate-reducing bacteria (SRB), phosphorus-accumulating organisms, and denitrifying bacteria (Pseudomonas sp.).

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] This invention overcomes the shortcomings of existing technologies by primarily utilizing multi-stage sulfur-cycle anaerobic treatment and a baffled design. Anaerobic treatment is a biological process used to decompose organic matter and remove most pollutants. The main advantages of anaerobic treatment include: no need for aeration, less sludge overproduction, high biogas energy content, low nutrient requirements, and the ability to achieve high organic loading. The multi-stage sulfur-cycle anaerobic device consists of a series of upflow anaerobic sludge bed reactors, where landfill leachate is forced to flow under and above a series of vertical baffles from the inlet to the outlet. The partitioned design of this device prevents horizontal movement of biomass, thus retaining a large amount of active biomass in each compartment. This characteristic not only improves the contact efficiency between pollutants and microorganisms but also extends the biomass retention time and enhances resistance to organic matter and hydraulic shock loads. Furthermore, some bacteria move horizontally along the reactor at a relatively slow rate, resulting in a cell retention time of 100 days when the hydraulic retention time is 20 hours. Therefore, when wastewater passes through the device, it can fully contact a large amount of active biomass within a short HRT (6-20 hours), while the effluent is relatively free of biological solids. Simultaneously, the device also utilizes sulfate-reducing bacteria in the acclimated sludge. On the one hand, it uses autotrophic sulfur-denitrifying microorganisms to degrade recalcitrant organic matter; on the other hand, it removes heavy metal ions from the landfill leachate through biochemical reactions, thereby effectively treating the primary leachate and improving pollutant removal efficiency. Attached Figure Description

[0017] Figure 1 This is a main sectional view of a sulfur-circulating multi-stage anaerobic device for treating landfill leachate, as described in this utility model.

[0018] Figure 2 This is a top view of a sulfur-circulating multi-stage anaerobic device for treating landfill leachate, as described in this utility model.

[0019] Figure 3 This is a side sectional view of a sulfur-circulating multi-stage anaerobic device for treating landfill leachate, as described in this utility model. Detailed Implementation

[0020] Specific implementation method one: Combining Figures 1 to 3 This embodiment describes a sulfur-cycle multi-stage anaerobic device for treating landfill leachate, which comprises a baffle 1, a gas outlet valve 2, an anaerobic baffle 3, a heater 4, a temperature sensor 6, an inlet valve 8, and at least four housings 9.

[0021] At least four boxes 9 are fixedly connected in pairs along the horizontal direction, and each box 9 has an anaerobic baffle 3 at one end of its internal top surface. A baffle 1 is provided on one side of the anaerobic baffle 3. The end face of the baffle 1 is fixedly connected to the inner wall of the box 9. A gas outlet valve 2 is provided at the top gas outlet of each box 9. A heater 4 and a temperature sensor 6 are provided at the bottom of the inside of the box 9. A liquid inlet is provided on the outer end face of the two outermost boxes 9, and an inlet valve 8 is provided on the liquid inlet.

[0022] In this specific embodiment, the sulfur-circulating multi-stage anaerobic digester is a rectangular box consisting of four identical chambers 9, each with a volume of 7 liters, for a total working volume of 28 liters. Each chamber 9 is further divided by a 45° inclined baffle 1, creating a descending and ascending zone within each chamber 9. Liquid flows from one chamber 9 to another, passing through a 10 mm × 50 mm vent located approximately 23 mm from the upper side of each chamber 9. A gas outlet valve 2 is connected to the vent side for collecting and removing harmful gases generated during the anaerobic process. The amount of harmful gases generated in each chamber 9 is monitored using an optical gas bubble meter. A heater 4 is installed at the bottom of each compartment to maintain the compartment temperature of the sulfur-circulating multi-stage anaerobic digester at 37 ± 0.5°C; a temperature sensor 6 is installed in each compartment to ensure a constant operating temperature.

[0023] The aged landfill leachate is collected and transferred to a dedicated storage tank. Using the aforementioned multi-stage anaerobic digester with sulfur circulation, inlet valve 8, heater 4, and temperature sensor 6 are opened, while supernatant sampling port 7, sludge sampling port 5, and gas outlet valve 2 are simultaneously closed. The wastewater to be treated enters the multi-stage anaerobic digester through inlet valve 8. By adding anaerobic biological agents and adjusting aeration time, dissolved oxygen content, and oxidation-reduction potential, microorganisms adhere to the anaerobic sludge, forming an effective sulfur circulation system and further improving the biological removal capacity of the landfill leachate. The added electron acceptors are mainly sodium sulfide and sodium sulfate, with a mass ratio of sodium sulfide to magnesium sulfate of 1:2. The added biological compound agent consists of Thiobacillus denitrificans, sulfate-reducing bacteria (SRB), phosphorus-accumulating organisms, and denitrifying bacteria (Pseudomonas sp.).

[0024] Specific Implementation Method Two: Combining Figures 1 to 3 This embodiment further defines the landfill leachate treatment device described in Specific Embodiment 1. The sulfur-circulating multi-stage anaerobic device for treating landfill leachate described in this embodiment has the same internal structure for the four boxes 9.

[0025] Specific implementation method three: Combining Figures 1 to 3 This embodiment further defines the landfill leachate treatment device described in Specific Embodiment Two. The sulfur-circulating multi-stage anaerobic device for treating landfill leachate described in this embodiment has a sludge sampling port 5 on the lower front of the box 9.

[0026] Specific implementation method four: Combination Figures 1 to 3 This embodiment further defines the landfill leachate treatment device described in Specific Embodiment 3. The sulfur-circulating multi-stage anaerobic device for treating landfill leachate described in this embodiment has a supernatant sampling port 7 on the upper back of the tank 9.

[0027] Specific Implementation Method Five: Combining Figures 1 to 3 This embodiment further defines the landfill leachate treatment device described in Specific Embodiment 4. In this embodiment, a sulfur-circulating multi-stage anaerobic device for treating landfill leachate is provided, wherein the centerline of the baffle 1 is inclined at 45° to the axis of the box body 9.

[0028] Specific Implementation Method Six: Combination Figures 1 to 3This embodiment further defines the landfill leachate treatment device described in Specific Embodiment 1. The sulfur-circulating multi-stage anaerobic device for treating landfill leachate described in this embodiment has a communication port on the upper part of the opposite end face of every two adjacent tanks 9.

[0029] Specific implementation method seven: Combination Figures 1 to 3 This embodiment further defines the landfill leachate treatment device described in Specific Embodiment Six. The sulfur-circulating multi-stage anaerobic device for treating landfill leachate described in this embodiment has four interconnected chambers 9.

[0030] Specific implementation method eight: Combination Figures 1 to 3 This embodiment further defines the landfill leachate treatment device described in Specific Embodiment Seven. The sulfur-circulating multi-stage anaerobic device for treating landfill leachate described in this embodiment uses an plexiglass box 9.

[0031] Working principle

[0032] In operation, the sulfur-circulating multi-stage anaerobic digester is a rectangular box consisting of four identical chambers 9, each with a volume of 7 liters, for a total working volume of 28 liters. Each chamber 9 is further divided by a 45° inclined baffle 1, creating a descending and ascending zone within each chamber 9. Liquid flows from one chamber 9 to another, passing through a 10 mm × 50 mm vent located approximately 23 mm from the upper side of each chamber 9. The vent is connected to a gas outlet valve 2 for collecting and removing harmful gases generated during the anaerobic process. The amount of harmful gases generated in each chamber 9 is monitored using an optical gas bubble meter. A heater 4 is installed at the bottom of each compartment to maintain the compartment temperature of the sulfur-circulating multi-stage anaerobic digester at 37 ± 0.5 °C; a temperature sensor 6 is installed in each compartment to ensure a constant operating temperature.

[0033] The aged landfill leachate is collected and transferred to a dedicated storage tank. Using the aforementioned multi-stage anaerobic digester with sulfur circulation, inlet valve 8, heater 4, and temperature sensor 6 are opened, while supernatant sampling port 7, sludge sampling port 5, and gas outlet valve 2 are simultaneously closed. The wastewater to be treated enters the multi-stage anaerobic digester through inlet valve 8. By adding anaerobic biological agents and adjusting aeration time, dissolved oxygen content, and oxidation-reduction potential, microorganisms adhere to the anaerobic sludge, forming an effective sulfur circulation system and further improving the biological removal capacity of the landfill leachate. The added electron acceptors are mainly sodium sulfide and sodium sulfate, with a mass ratio of sodium sulfide to magnesium sulfate of 1:2. The added biological compound agent consists of Thiobacillus denitrificans, sulfate-reducing bacteria (SRB), phosphorus-accumulating organisms, and denitrifying bacteria (Pseudomonas sp.).

Claims

1. A sulfur-circulating multi-stage anaerobic digester for treating landfill leachate, characterized in that: It includes a baffle (1), a gas outlet valve (2), an anaerobic baffle (3), a heater (4), a temperature sensor (6), an inlet valve (8), and at least four chambers (9). At least four boxes (9) are fixedly connected in pairs along the horizontal direction. Each box (9) has an anaerobic baffle (3) at one end of its inner top surface. A baffle (1) is provided on one side of the anaerobic baffle (3). The end face of the baffle (1) is fixedly connected to the inner wall of the box (9). A gas outlet valve (2) is provided at the top outlet of each box (9). A heater (4) and a temperature sensor (6) are provided at the bottom of the inside of the box (9). A liquid inlet is provided on the outer end face of the two outermost boxes (9), and an inlet valve (8) is provided on the liquid inlet.

2. The sulfur-circulating multi-stage anaerobic digester for treating landfill leachate according to claim 1, characterized in that: The internal structures of the four boxes (9) are the same.

3. A sulfur-circulating multi-stage anaerobic digester for treating landfill leachate according to claim 2, characterized in that: The lower front of the box (9) is provided with a sludge sampling port (5).

4. A sulfur-circulating multi-stage anaerobic digester for treating landfill leachate according to claim 3, characterized in that: The upper part of the back of the box (9) is provided with a supernatant sampling port (7).

5. A sulfur-circulating multi-stage anaerobic digester for treating landfill leachate according to claim 4, characterized in that: The centerline of the baffle (1) is inclined at 45° to the axis of the box (9).

6. A sulfur-circulating multi-stage anaerobic digester for treating landfill leachate according to claim 1, characterized in that: A connecting port is provided on the upper part of the opposite end face of each pair of adjacent boxes (9).

7. A sulfur-circulating multi-stage anaerobic digester for treating landfill leachate according to claim 6, characterized in that: The four boxes (9) are internally connected.

8. A sulfur-circulating multi-stage anaerobic digester for treating landfill leachate according to claim 7, characterized in that: The box (9) is made of plexiglass.

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