Anti-scaling landfill leachate anaerobic treatment system and method

Abstract

The invention belongs to the technical field of landfill leachate anaerobic treatment, and particularly relates to an anti-scaling landfill leachate anaerobic treatment system and method. The anti-scaling landfill leachate anaerobic treatment system comprises a tank body and an anaerobic tank, the tank body is connected with the anaerobic tank through a liquid guide pipe; a filter assembly is arranged in the tank body, and the interior of the tank body is divided into an upper cavity and a lower cavity by the filter assembly; a feed hopper for adding a scale inhibitor is arranged at the upper part of the tank body, and the feed hopper is communicated with the upper cavity; a stirring assembly is arranged in the tank body; and the stirring assembly is used for enabling the garbage penetrating fluid and the scale inhibitor to be fully combined and subjected to chemical reaction. According to the anaerobic treatment system and method provided by the invention, the problem of scaling in landfill leachate treatment is solved, and meanwhile, the anaerobic treatment efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of anaerobic treatment of landfill leachate, and in particular relates to an anti-scaling landfill leachate anaerobic treatment system and method. Background Art

[0002] Landfill leachate is a complex and highly polluting wastewater containing a large amount of organic pollutants, heavy metals and salts, which is difficult to treat. Anaerobic biological treatment technology has become an important method for landfill leachate treatment due to its advantages such as efficient degradation of organic matter, production of biogas and energy saving.

[0003] As the main body of anaerobic biological treatment technology, the development of anaerobic reactors has gone through three eras. The first generation of reactors is represented by anaerobic digesters. The residence time of anaerobic sludge in the reactor is the same as the residence time of wastewater, which belongs to a low-load system; the second generation of reactors is represented by UASB, AF, ABF, etc. The reactors can separate sludge well and shorten the residence time and hydraulic retention time, which belongs to a high-load system; the third generation of reactors is represented by IC and EGSB. The reactors can not only separate sludge, reduce the residence time and hydraulic retention time, but also ensure that the sludge and wastewater are fully mixed and reacted, so as to achieve the purpose of efficient anaerobic removal of organic matter.

[0004] However, the current anaerobic treatment system still faces scaling problems during the treatment of landfill leachate. The high hardness and high alkalinity in the leachate will cause calcium scale to form on the surface of the filler, resulting in a reduction in the amount of sludge attached, which in turn affects the efficiency of the anaerobic reaction. In addition, the scaling problem is particularly serious during high-load operation, which increases the equipment maintenance cost and affects the long-term operation stability.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] In order to overcome the problems existing in the background technology, the present invention provides an anti-scaling garbage leachate anaerobic treatment system and method, which reduces the scaling of the leachate in the anaerobic reactor by adding a scale inhibitor and combining physical stirring and filtration technology.

[0007] In order to achieve the above technical objectives, the present invention provides the following technical solutions:

[0008] A scale-proof garbage leachate anaerobic treatment system, the scale-proof garbage leachate anaerobic treatment system comprising: a tank body (1) and an anaerobic tank (2); the tank body (1) and the anaerobic tank (2) are connected via a liquid guide tube (2);

[0009] A filter assembly (5) is disposed inside the tank body (1), and the interior of the tank body (1) is divided into an upper chamber and a lower chamber by the filter assembly (5);

[0010] A feed hopper (8) for adding antiscalant is arranged at the upper part of the tank body (1), and the feed hopper (8) is communicated with the upper chamber;

[0011] A stirring assembly (4) is arranged in the tank body (1); the stirring assembly (4) is used to fully mix the garbage leachate with the scale inhibitor in the upper chamber and cause a chemical reaction.

[0012] Furthermore, the filter assembly (5) comprises an upper filter plate (51) and a lower filter cloth (52) located below the upper filter plate (51);

[0013] The upper filter plate (51) and the lower filter cloth (52) are all fixedly connected to the inner wall of the tank body (1) on all sides.

[0014] Furthermore, a solid descaling agent is filled between the upper filter plate (51) and the lower filter cloth (52);

[0015] The diameter of the filter holes of the upper filter plate (51) is greater than the diameter of the filter holes of the lower filter cloth (52).

[0016] Furthermore, the stirring assembly (4) comprises a rotating shaft (41), a plurality of stirring blades (42) and a driving motor (43); the driving motor is arranged on the top outer wall of the tank body (1);

[0017] The rotating shaft (41) is vertically arranged in the upper chamber of the tank body (1), the stirring blade (42) is fixedly connected to the rotating shaft (41), and the stirring blade (42) is arranged in the upper chamber to stir the scale inhibitor in the upper chamber;

[0018] The top end of the rotating shaft (41) passes through the tank body (1) and is connected to the driving motor (43), and the bottom end of the rotating shaft (41) passes through the upper filter plate (51) and extends between the upper filter plate (51) and the lower filter cloth (52); the bottom end of the rotating shaft (41) is fixedly connected to a bottom stirring plate; the bottom stirring plate is horizontally arranged between the upper filter plate and the lower filter cloth and is used to stir the solid descaling agent.

[0019] Furthermore, the feed hopper (8) is arranged on the top surface of the tank body (1).

[0020] Furthermore, the anaerobic tank (2) and the lower chamber of the tank body (1) are connected via a liquid conduit (2).

[0021] Furthermore, the liquid guiding tube (2) is made of PE or PPR material.

[0022] Furthermore, the anaerobic tank adopts an internal circulation anaerobic reactor.

[0023] An anti-scaling garbage leachate anaerobic treatment method, the method comprising:

[0024] Add the antiscalant into the upper chamber of the tank through the feed hopper, start the drive motor to drive the rotating shaft to rotate; the rotating shaft rotates at a speed of 30 to 50 rpm;

[0025] The garbage leachate flows through the filter cloth under the upper filter plate and enters the lower chamber of the tank;

[0026] The garbage leachate in the lower chamber of the tank body enters the anaerobic tank through the liquid guide pipe for anaerobic treatment.

[0027] Furthermore, the anaerobic tank adopts an internal circulation anaerobic reactor; the startup operation of the internal circulation anaerobic reactor includes the following three stages:

[0028] The first stage is the sludge acclimation period: after inoculating the anaerobic digestion sludge in the internal circulation anaerobic reactor, the leachate, domestic sewage and / or boiler wastewater are pumped into the reactor in a ratio of 1:1, the water inlet is stopped, the circulation pump is turned on, and it is continuously operated for 2-5 days for acclimation. After acclimation, continuous water inlet is started. The COD concentration of the inlet water of the anaerobic reactor is 50,000-65,000 mg / L. After 7 days of acclimation, the COD removal rate increases and reaches more than 80%;

[0029] The second stage is the load increase period: the volume load of the reactor is increased to 17.7 kg COD / (m 3 ·d), if the COD removal rate of the reactor does not recover to more than 80% after 1-2 days of continued operation, the removal effect of the reactor needs to be restored by reducing the load;

[0030] The third stage is the stable operation period: after 0.5-1.5 months of continuous operation, the COD removal efficiency is stabilized at more than 80%, and the volatile acid is less than 1500mg / L. 3 Garbage leachate produces 20~25.2m 3 Biogas; After the reactor has been running for 2-3 months, the reactor startup is completed.

[0031] The beneficial effects of the present invention are:

[0032] The anti-scaling garbage leachate anaerobic treatment system provided by the present invention uses a scale inhibitor in conjunction with a high-efficiency stirring and mixing system, thereby improving the chemical reaction efficiency between the garbage leachate and the scale inhibitor, thereby reducing the formation of scale. In addition, the system also uses multi-stage filtration to effectively intercept residual scale in the leachate, and fully reacts with the solid descaling agent between the upper filter plate and the lower filter cloth to gradually reduce the scale in the leachate, thereby avoiding the blockage of subsequent pipelines and reactors, ensuring the long-term stable operation of the internal equipment of the system while improving the scale inhibition efficiency, and reducing the frequency of equipment maintenance.

[0033] The anti-scaling landfill leachate anaerobic treatment method adopted by the present invention reduces the volume load of the existing anaerobic reactor from 7.5kg COD / m 3 ·Raised to 8kg COD / m 3 ·d or more, the multi-reaction zone anaerobic reactor can reduce the sludge loss phenomenon of the existing anaerobic reactor and increase the sludge concentration in the anaerobic reactor. At the same time, due to the high COD of the influent of the multi-reaction zone high-efficiency anaerobic reactor, a large amount of alkalinity can be produced to control the acidification degree inside the anaerobic reactor and produce high-efficiency granular sludge, which is helpful to improve the volume load of the anaerobic reactor. At the same time, due to the large number of microorganisms in the multi-reaction zone anaerobic reactor, the anaerobic granular sludge is often in a semi-starved state, which is helpful to improve the decomposition rate of organic pollutants in wastewater by anaerobic microorganisms. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a front view of the structure of the anti-scaling garbage leachate anaerobic treatment system in an embodiment of the present invention;

[0035] Figure 2 It is a cross-sectional view of a tank of an anti-scaling garbage leachate anaerobic treatment system in an embodiment of the present invention;

[0036] Figure 3 This is a COD detection data diagram of the anti-scaling garbage leachate anaerobic treatment system in the embodiment of the present invention;

[0037] Figure 4 This is a pH detection data diagram of the operation of the anti-scaling garbage leachate anaerobic treatment system in an embodiment of the present invention;

[0038] Figure 5 It is a pH and VFA detection data diagram of the anti-scaling landfill leachate anaerobic treatment system in the embodiment of the present invention;

[0039] Figure numerals: 1. tank body, 11. feed hopper; 2. liquid guide tube; 3. anaerobic tank; 4. stirring assembly, 41. rotating shaft, 42. stirring blade, 43. driving motor; 5. filtering assembly, 51. upper filter plate, 52. lower filter cloth 52; 6. solid descaling agent; 7. stirring plate; 8. antiscaling agent. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the technical solution of the present invention will be described in detail 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, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0041] Example 1: An anti-scaling garbage leachate anaerobic treatment system, such as Figure 1-2 The anti-scaling garbage leachate anaerobic treatment system comprises: a tank body 1 and an anaerobic tank 2; the tank body 1 and the anaerobic tank 2 are connected by a liquid guide pipe 2;

[0042] A filter assembly 5 is disposed inside the tank body 1, and the inside of the tank body 1 is divided into an upper chamber and a lower chamber by the filter assembly 5;

[0043] A feed hopper 8 for adding antiscalant is provided on the upper part of the tank body 1, and the feed hopper 8 is communicated with the upper chamber; the antiscalant is added into the tank body through the feed hopper, so that the antiscalant reacts chemically with the garbage leachate contained in the tank body, thereby reducing the generation of scale by the garbage leachate; the garbage leachate also enters the tank body through the feed hopper;

[0044] A stirring assembly 4 is arranged in the tank body 1; the stirring assembly 4 is used to fully combine the garbage leachate with the antiscalant and cause a chemical reaction.

[0045] In this embodiment, the filter assembly 5 includes an upper filter plate 51 and a lower filter cloth 52 located below the upper filter plate 51;

[0046] The upper filter plate 51 and the lower filter cloth 52 are fixedly connected to the inner wall of the tank body 1 on all sides.

[0047] In this embodiment, a solid descaling agent is filled between the upper filter plate 51 and the lower filter cloth 52;

[0048] The diameter of the filter holes of the upper filter plate 51 is greater than the diameter of the filter holes of the lower filter cloth 52. Specifically, in this embodiment, the diameter of the filter holes of the upper filter plate is 2 mm, and the diameter of the filter holes of the lower filter cloth is 0.5 mm.

[0049] After the garbage leachate fully reacts with the scale inhibitor, a small amount of the remaining scale in the garbage leachate will pass through the upper filter plate and react with the solid scale remover between the upper filter plate and the lower filter cloth, so that the scale is dissolved and flows out through the lower filter cloth, thereby reducing the scale in the garbage leachate. The diameter of the filter hole of the upper filter plate is larger than the diameter of the filter hole of the lower filter cloth, so that a part of the scale will pass through the upper filter plate, but cannot pass through the lower filter cloth, so that the scale fully reacts with the solid scale remover between the upper filter plate and the lower filter cloth, thereby reducing the scale in the garbage leachate.

[0050] In this embodiment, the stirring assembly 4 includes a rotating shaft 41, a plurality of stirring blades 42 and a driving motor 43;

[0051] The rotating shaft 41 is vertically arranged in the upper chamber of the tank body 1, the stirring blade 42 is fixedly connected to the rotating shaft 41, and the stirring blade 42 is arranged in the upper chamber to stir the scale inhibitor in the upper chamber;

[0052] The top end of the rotating shaft 41 passes through the tank body 1 and is connected to the driving motor 43, and the bottom end of the rotating shaft 41 passes through the upper filter plate 51 and extends between the upper filter plate 51 and the lower filter cloth 52; the bottom end of the rotating shaft 41 is fixedly connected to a bottom stirring plate; the bottom stirring plate is horizontally arranged between the upper filter plate and the lower filter cloth, and is used to stir the solid descaling agent. Among them, the driving motor 43 is fixedly arranged on the top outer wall of the tank body 1, and the output shaft of the driving motor is fixedly connected to the top end of the rotating shaft 41;

[0053] In this embodiment, the feed hopper 8 is arranged on the top surface of the tank body 1 .

[0054] In this embodiment, the anaerobic tank 2 and the lower chamber of the tank body 1 are connected via a liquid conduit 2 .

[0055] In this embodiment, the catheter 2 is made of PE or PPR material. The above materials have the advantages of energy saving and material saving, environmental protection, light weight and high strength, corrosion resistance, smooth inner wall without scaling, simple construction and maintenance, and long service life.

[0056] In this embodiment, the anaerobic tank adopts an internal circulation anaerobic reactor. The internal circulation anaerobic reactor adopted by the present invention is a conventional technology; the internal circulation anaerobic reactor is composed of 2 layers of UASB reactors connected in series; it consists of two upper and lower reaction chambers. Wastewater flows from bottom to top in the reactor, pollutants are adsorbed and degraded by bacteria, and purified water flows out from the upper part of the reactor. According to the function, the internal circulation anaerobic reactor is divided into 5 zones from bottom to top: mixing zone, the first anaerobic zone, the second anaerobic zone, the sedimentation zone and the gas-liquid separation zone. Mixing zone: The mud-water mixture of the water inlet at the bottom of the reactor, the granular sludge and the reflux of the gas-liquid separation zone are effectively mixed in this zone.

[0057] Anaerobic zone 1: The mud-water mixture formed in the mixing zone enters this zone. Under the action of high-concentration sludge, most of the organic matter is converted into biogas. The rising flow of the mixed liquid and the violent disturbance of the biogas cause the sludge in the reaction zone to expand and fluidize, strengthen the contact between the mud and water surfaces, and thus maintain high activity of the sludge. As the biogas production increases, part of the mud-water mixture is lifted by the biogas to the gas-liquid separation zone at the top.

[0058] Second anaerobic zone: After the wastewater is treated in the first anaerobic zone, except for a part of it being lifted by biogas, the rest enters the second anaerobic zone through the three-phase separator. The sludge concentration in this zone is low, and most of the organic matter in the wastewater has been degraded in the first anaerobic zone, so the amount of biogas produced is small. The biogas is introduced into the gas-liquid separation zone through the biogas pipe, which has little disturbance to the second anaerobic zone, which provides favorable conditions for the retention of sludge.

[0059] Sedimentation zone: The mud-water mixture in the second anaerobic zone is separated into solid and liquid in the sedimentation zone, the supernatant is discharged from the outlet pipe, and the precipitated granular sludge is returned to the sludge bed of the second anaerobic zone.

[0060] Gas-liquid separation zone: The biogas in the lifted mixture is separated from the mud and water and exported to the treatment system. The mud and water mixture returns to the mixing zone at the bottom along the reflux pipe and is fully mixed with the sludge and influent at the bottom of the reactor, thus realizing the internal circulation of the mixed liquid.

[0061] The working principle of the anti-scaling garbage leachate anaerobic treatment system of the present invention is:

[0062] After the driving motor is turned on, the rotating shaft drives the stirring blade to rotate; the stirring of the stirring blade improves the chemical reaction efficiency between the garbage leachate and the scale inhibitor, thereby reducing the formation of scale;

[0063] The multi-stage filtration of the filter assembly is used to effectively intercept the residual scale in the leachate. Between the upper filter plate and the lower filter cloth, the solid descaling agent and the residual scale in the filtrate are fully reacted through the rotation of the bottom stirring plate, so that the scale in the leachate is gradually reduced, thereby avoiding the blockage of subsequent pipelines and reactors. While improving the scale inhibition efficiency, it ensures the long-term stable operation of the internal equipment of the system and reduces the frequency of equipment maintenance;

[0064] The liquid guide pipe is arranged below the lower filter cloth, so that the garbage leachate flowing to the anaerobic tank through the liquid guide pipe contains less scaling after being fully filtered, thereby making the transmission of the garbage leachate smoother and further improving the efficiency of garbage treatment.

[0065] The present invention provides an anti-scaling garbage leachate anaerobic treatment system, which aims to solve the scaling problem in the treatment of garbage leachate and improve the efficiency of anaerobic treatment. The system of the present invention includes a tank body, a liquid guide tube and an anaerobic tank. The tank body is added with a scale inhibitor and is equipped with a stirring component to ensure that the garbage leachate and the scale inhibitor are fully mixed and reacted. A double-layer filter component is designed in the system to filter the residual scaling materials, and a stirring device is used to promote the reaction between the scale remover and the scaling materials, thereby effectively reducing the scaling materials in the garbage leachate. In addition, the system also uses a high-efficiency IC reactor to further improve the treatment efficiency. The reactor is divided into multiple zones to ensure the decomposition of organic matter and the generation and maintenance of anaerobic granular sludge. The entire system not only reduces secondary pollution to the ecological environment, but also increases the volumetric load of the anaerobic reactor, greatly improving the anaerobic treatment efficiency of garbage leachate.

[0066] Example 2: An anti-scaling garbage leachate anaerobic treatment method, using the system described in Example 1, the method comprises:

[0067] Add the antiscalant into the upper chamber of the tank through the feed hopper, start the drive motor, and drive the rotating shaft to rotate;

[0068] The garbage leachate flows through the filter cloth under the upper filter plate and enters the lower chamber of the tank;

[0069] The garbage leachate in the lower chamber of the tank body enters the anaerobic tank through the liquid guide pipe for anaerobic treatment.

[0070] The anaerobic tank adopts an internal circulation anaerobic reactor;

[0071] The startup operation of the internal circulation anaerobic reactor includes the following three stages:

[0072] The first stage is the sludge acclimation period: after inoculating the anaerobic digestion sludge in the internal circulation anaerobic reactor, the leachate and wastewater (domestic sewage and boiler wastewater) are pumped into the reactor in a ratio of 1:1, the water intake is stopped, and the circulation pump is turned on (circulation pump flow rate 100m 3 / h, rising flow rate 2m / h), run continuously for 2 days, start continuous water inflow after 2 days of acclimatization, the COD concentration of the influent of the anaerobic reactor is 50000~65000mg / L, after 7 days of acclimatization, the COD removal rate increases and reaches more than 80%;

[0073] The second stage is the load increase period: the volume load of the reactor is increased to 17.7 kg COD / (m 3 ·d), if the COD removal rate of the reactor does not recover to more than 80% after 1-2 days of continued operation, the removal effect of the reactor needs to be restored by reducing the load;

[0074] The third stage is the stable operation period: after 0.5-1.5 months of continuous operation, the COD removal efficiency is stabilized at more than 80%, the volatile acid is less than 1500mg / L, and the 1m 3 The landfill leachate produces 20 to 25.2 m3 of biogas; after the reactor has been running for 2 to 3 months, the reactor startup is completed.

[0075] In order to more clearly illustrate the present invention, it is described in detail through the following examples.

[0076] Reference Figure 1 , including a tank body 1 for storing garbage leachate, an anaerobic tank 3 is arranged below the tank body 1, a liquid guide tube 2 is connected between the tank body 1 and the anaerobic tank 3, one end of the liquid guide tube 2 is connected to the tank body 1, and the other end is connected to the anaerobic tank 3, a scale inhibitor 8 is added to the tank body 1, and a stirring component 4 for fully stirring the scale inhibitor 8 and the garbage leachate is also connected to the tank body 1. When in use, the scale inhibitor 8 is added to the tank body 1, and the stirring component 4 is started to make the scale inhibitor 8 and the garbage leachate fully react, and then the reacted garbage leachate is introduced into the anaerobic tank 3 through the liquid guide tube 2, so as to perform anaerobically treatment on the garbage leachate.

[0077] Figure 2 is a cross-sectional view of the tank of the anti-scaling garbage leachate anaerobic treatment system of the present invention; Figure 2The tank body 1 is relatively fixedly connected to the bracket, a feed hopper 11 is arranged at the top of the tank body 1, the bottom of the feed hopper 11 is connected to the tank body 1, and the scale inhibitor 8 is placed in the feed hopper 11. The stirring assembly 4 includes a rotating shaft 41, a stirring blade 42 and a driving motor 43. The rotating shaft 41 is vertically arranged, and its top end is rotatably connected to the tank body 1. A plurality of stirring blades 42 are arranged, which are evenly distributed on the outer wall of the rotating shaft 41 and fixedly connected to the rotating shaft 41. The driving motor 43 is vertically arranged and fixedly connected to the outer wall of the tank body 1, and the output shaft of the driving motor 43 is fixedly connected to the top of the rotating shaft 41. When in use, the scale inhibitor 8 is added into the tank body 1 through the feed hopper 11, and the driving motor 43 is started to drive the rotating shaft 41 to rotate, so that the stirring blades 42 on the rotating shaft 41 rotate to stir, so that the garbage leachate and the scale inhibitor 8 are fully combined and chemically reacted.

[0078] Reference Figure 2 , a filter assembly 5 is connected inside the tank body 1, and the filter assembly 5 includes an upper filter plate 51 and a lower filter cloth 52 located below the upper filter plate 51. The upper filter plate 51 and the lower filter cloth 52 are both arranged horizontally and fixedly connected to the inner wall of the tank body 1, and the diameter of the filter hole of the upper filter plate 51 is larger than the diameter of the filter hole of the lower filter cloth 52. A solid descaling agent 6 is placed between the upper filter plate 51 and the lower filter cloth 52. The bottom end of the rotating shaft 41 is located between the upper filter plate 51 and the lower filter cloth 52, and the rotating shaft 41 is rotatably connected to the upper filter plate 51. The bottom end of the rotating shaft 41 is connected to a stirring plate 7, which is a horizontally arranged rectangular plate. The rotating shaft 41 is fixedly connected at the center of the stirring length direction. When in use, the scale remaining in the garbage leachate is first filtered by the upper filter plate 51 to prevent the scale from flowing into the liquid guide tube 2, but a small amount of scale can still pass through the upper filter plate 51 and enter between the upper filter plate 51 and the lower filter cloth 52, and then the stirring plate 7 is driven to rotate by the rotating shaft 41, so that the scale fully reacts with the fixed descaling agent, dissolves the scale, and flows out through the lower filter cloth 52. The liquid guide tube 2 is made of PE or PPR material, and one end of the liquid guide tube 2 connected to the tank body 1 is located below the lower filter cloth 52. When in use, after the garbage leachate is filtered by the lower filter cloth 52, it enters the anaerobic tank 3 through the liquid guide tube 2 for anaerobic treatment.

[0079] The anti-scaling garbage leachate anaerobic treatment system comprises a tank for storing garbage leachate, an anaerobic tank and a liquid guide pipe connected thereto. In this embodiment, the anti-scaling garbage leachate anaerobic treatment system, design parameters and actual operation data records are shown in Table 1:

[0080] Table 1 Design parameters and actual operation data of anti-scaling landfill leachate anaerobic treatment system

[0081]

[0082]

[0083] The inoculum sludge of the anaerobic reactor was taken from the anaerobic digestion sludge of the hydrolysis and acidification tank of a waste power plant. The ratio of mixed liquor volatile suspended solids (MLVSS) to mixed liquor suspended solids (MLSS) in the inoculum sludge was 0.58, and the MLVSS was 28.8 g / L. Before the reactor was started, 400 tons of inoculum sludge was connected, and the sludge moisture content was 85%. Because the landfill leachate contains certain toxicity, a sufficient amount of sludge was inoculated at one time before starting the acclimation to reduce the sludge load and avoid the toxic impact of toxic substances on anaerobic microorganisms.

[0084] The startup and operation of the anaerobic reactor is divided into three stages:

[0085] The first stage is the sludge acclimation period. After the sludge is inoculated, the leachate, domestic sewage from the waste power plant, and boiler wastewater are pumped into the reactor in a ratio of 1:1. Then the water inlet is stopped and the circulation pump is turned on (circulation pump flow rate 100m3 / h, rising flow rate 2m / h). It is operated continuously for 2 days. After 2 days of acclimation, continuous water inlet begins. The COD concentration of the inlet water of the anaerobic reactor is between 50,000 and 65,000 mg / L. The volume load is increased by controlling the water inlet. The starting load is about 6 kg COD / (m3·d). After 7 days of acclimation, the COD removal rate gradually increases and reaches more than 80%.

[0086] The second stage is the load increase period. Each time the water inlet volume is increased by 10-20m3, the load is increased by 1.0-2.0kg COD / (m3 / d). Every time the water inlet load of the anaerobic reactor is increased, the COD removal rate of the reactor will decrease. However, after 1-2 days of continued operation, the COD removal rate of the reactor will recover to more than 80%. After operation, the volume load of the reactor increased from 6kgCOD / ((m3·d) to 17.7kg COD / (m3·d). When the load was further increased, the COD removal effect dropped below 80%. At this time, the volatile acidity increased significantly and the effluent water quality deteriorated significantly, indicating that the increase in load destroyed the normal operation of the anaerobic reactor. The removal effect of the reactor was restored by reducing the load.

[0087] The third stage is the stable operation period. After one month of continuous operation, the COD removal efficiency is stable at more than 80%, the volatile acid is less than 1500mg / L, and about 0.42m3 of biogas can be produced for every 1kg of COD removed (that is, 1m3 of landfill leachate can produce 20-25.2m3 of biogas). Although the gas production fluctuates, it is generally stable. It can be considered that after two months of operation, the reactor startup is basically completed.

[0088] Analyze the main test items of effluent water quality to determine the operating status of the anaerobic system:

[0089] (1) COD: COD is a key indicator for the operation and control of anaerobic systems. Figure 3 As shown, the inlet COD is between 50000 and 65000 mg / L, with an average value of 57629 mg / L. The effluent COD is stable at around 8500 mg / L, which is within the design control standard of COD < 15000 mg / L. The COD removal rate remains at around 86%, which is higher than the design value (design removal rate 75%), achieving the designed effluent target.

[0090] (2) pH: pH is an important parameter that affects the operation of anaerobic reactors. Figure 4 As shown in the figure, the effluent pH is stable between 7.3 and 7.7, which is slightly higher than the designed control pH value of 6.8 to 7.4. In addition to being related to the influent quality, pH is also affected by alkalinity and VFA content. The higher alkalinity in the anaerobic tank may have led to a higher pH.

[0091] (3) VFA: VFA is an important reference indicator for the stable operation of the reactor. Although the substrate of methanogens is a small molecular weight organic acid, if the acid production rate is greater than the methane production rate, excessive VFA will lead to a low pH and inhibit the survival of methanogens. Compared with monitoring pH, VFA can better reflect the survival status of microorganisms in the anaerobic tank. Figure 5 As shown in the figure, during operation, when the VFA content is greater than 1500 mg / L, the growth of methanogens will be inhibited. The VFA of the effluent of the anaerobic system is basically maintained at 1200-1500 mg / L, which is within the design standard VFA<3000 mg / L.

[0092] In addition, the ratio of VFA / ALK reflects the buffering capacity of the anaerobic system to changes in organic acids, and this ratio is generally not greater than 0.6. The VFA of the effluent from the anaerobic system is less than 1500 mg / L, which is lower than the design control parameter of 3000 mg / L, and VFA / ALK≈0.1, indicating that the anaerobic system has a good buffering capacity.

[0093] According to the water quality analysis of the anaerobic leachate treatment system, it can be seen that the anaerobic system has basically met the design requirements, among which: the effluent COD and VFA both meet the design index requirements and are in a good state range; although the pH is slightly high, the VFA / ALK is in a good state range.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An anti-scaling landfill leachate anaerobic treatment system, characterized in that: The anti-scaling garbage leachate anaerobic treatment system comprises: a tank body (1) and an anaerobic tank (2); the tank body (1) and the anaerobic tank (2) are connected via a liquid conduit (2); A filter assembly (5) is disposed inside the tank body (1), and the interior of the tank body (1) is divided into an upper chamber and a lower chamber by the filter assembly (5); A feed hopper (8) for adding antiscalant is arranged at the upper part of the tank body (1), and the feed hopper (8) is communicated with the upper chamber; A stirring assembly (4) is arranged in the tank body (1); the stirring assembly (4) is used to fully mix the garbage leachate with the scale inhibitor in the upper chamber and cause a chemical reaction.

2. The anti-scaling anaerobic treatment system for landfill leachate according to claim 1, characterized in that: The filter assembly (5) comprises an upper filter plate (51) and a lower filter cloth (52) located below the upper filter plate (51); The upper filter plate (51) and the lower filter cloth (52) are fixedly connected to the inner wall of the tank body (1) on all sides.

3. The anti-scaling landfill leachate anaerobic treatment system according to claim 2, characterized in that: A solid descaling agent is filled between the upper filter plate (51) and the lower filter cloth (52); The diameter of the filter holes of the upper filter plate (51) is greater than the diameter of the filter holes of the lower filter cloth (52).

4. The anti-scaling landfill leachate anaerobic treatment system according to claim 2, characterized in that: The stirring assembly (4) comprises a rotating shaft (41), a plurality of stirring blades (42) and a driving motor (43); The rotating shaft (41) is vertically arranged in the upper chamber of the tank body (1), the stirring blade (42) is fixedly connected to the rotating shaft (41), and the stirring blade (42) is arranged in the upper chamber to stir the scale inhibitor in the upper chamber; The top end of the rotating shaft (41) passes through the tank body (1) and is connected to the driving motor (43), and the bottom end of the rotating shaft (41) passes through the upper filter plate (51) and extends between the upper filter plate (51) and the lower filter cloth (52); the bottom end of the rotating shaft (41) is fixedly connected to a bottom stirring plate; the bottom stirring plate is horizontally arranged between the upper filter plate and the lower filter cloth and is used to stir the solid descaling agent.

5. The anti-scaling landfill leachate anaerobic treatment system according to claim 1, characterized in that: The feed hopper (8) is arranged on the top surface of the tank body (1).

6. The anti-scaling landfill leachate anaerobic treatment system according to claim 1, characterized in that: The anaerobic tank (2) and the lower chamber of the tank body (1) are connected via a liquid conduit (2).

7. The anti-scaling landfill leachate anaerobic treatment system according to claim 6, characterized in that: The liquid guiding tube (2) is made of PE or PPR material.

8. The anti-scaling landfill leachate anaerobic treatment system according to claim 1, characterized in that: The anaerobic tank adopts an internal circulation anaerobic reactor.

9. An anti-scaling landfill leachate anaerobic treatment method, using the system according to any one of claims 1 to 8, characterized in that: The method comprises: Add the antiscalant into the upper chamber of the tank through the feed hopper, start the drive motor, and drive the rotating shaft to rotate; The garbage leachate flows through the filter cloth under the upper filter plate and enters the lower chamber of the tank; The garbage leachate in the lower chamber of the tank body enters the anaerobic tank through the liquid guide pipe for anaerobic treatment.

10. The method for anaerobic treatment of anti-scaling landfill leachate according to claim 9, characterized in that: The anaerobic tank adopts an internal circulation anaerobic reactor; the startup operation of the internal circulation anaerobic reactor includes the following three stages: The first stage is the sludge acclimation period: after inoculating the anaerobic digestion sludge in the internal circulation anaerobic reactor, the leachate, domestic sewage and / or boiler wastewater are pumped into the reactor in a ratio of 1:1, the water inlet is stopped, the circulation pump is turned on, and it is continuously operated for 2-5 days for acclimation. After acclimation, continuous water inlet is started. The COD concentration of the inlet water of the anaerobic reactor is 50,000-65,000 mg / L. After 7 days of acclimation, the COD removal rate increases and reaches more than 80%; The second stage is the load increase period: the volume load of the reactor is increased to 17.7 kg COD / (m 3 ·d), if the COD removal rate of the reactor does not recover to more than 80% after 1-2 days of continued operation, the removal effect of the reactor needs to be restored by reducing the load; The third stage is the stable operation period: after 0.5-1.5 months of continuous operation, the COD removal efficiency is stabilized at more than 80%, and the volatile acid is less than 1500mg / L. 3 Garbage leachate produces 20~25.2m 3 Biogas; After the reactor has been running for 2-3 months, the reactor startup is completed.

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