Household refuse landfill leachate concentrated water treatment system and treatment process

Abstract

The invention relates to the field of wastewater treatment, in particular to a domestic waste landfill leachate concentrated water treatment system and process, and the treatment system is sequentially provided with a filter tank, an organic nanofiltration membrane is arranged in the filter tank, and the filter tank is used for carrying out reduction treatment on leachate concentrated water; the first homogenizing reaction tank is used for carrying out first-time PH regulation and first-time coagulation treatment on the reduced wastewater; the first solid-liquid separation equipment is used for carrying out solid-liquid separation on the mud-water mixture subjected to the first coagulation treatment and extracting solid humic acid; the second homogenizing reaction tank is used for carrying out second-time PH regulation and second-time coagulation treatment on the residual solution after the solid humic acid is extracted; the second solid-liquid separation equipment is used for carrying out solid-liquid separation on a mud-water mixture subjected to secondary coagulation treatment, and an organic nanofiltration membrane is arranged in the filter box for filtering landfill leachate concentrated water, so that the treatment capacity of subsequent steps is reduced, and the energy consumption and the medicament consumption are reduced.

Description

Technical Field

[0001] The present application relates to the field of wastewater treatment, and in particular to a system and process for treating concentrated water from leachate from a domestic waste landfill. Background Art

[0002] Leachate refers to a high-concentration organic wastewater that comes from the moisture contained in the garbage itself in the landfill, the rain and snow water that enters the landfill, and other moisture, minus the saturated water holding capacity of the garbage and covering soil layers, and passes through the garbage layer and covering soil layer.

[0003] The concentrated water of leachate from domestic waste landfills has a high organic content. In the existing technology, high-pressure reverse osmosis is often used to re-treat this high-concentration wastewater. The system recovery rate is low, the energy consumption is high, and the membrane system is prone to fouling and clogging. In addition, due to the high organic content in the concentrated water of the leachate, the use of subsequent evaporators is affected. Organic matter will affect the boiling point during evaporation and affect the processing volume. Summary of the invention

[0004] In order to solve the above problems, the present application provides a system and process for treating concentrated water of leachate from a domestic waste landfill.

[0005] The present application provides a landfill leachate concentrate treatment system that adopts the following technical solution: A system for treating concentrated water from leachate from a domestic waste landfill is provided in the following order: Filter box with built-in organic nanofiltration membrane for reducing the amount of leachate concentrate; The first homogenization reaction tank is used to perform the first pH adjustment and the first coagulation treatment on the reduced wastewater; The first solid-liquid separation equipment performs solid-liquid separation on the mud-water mixture after the first coagulation treatment and extracts solid humic acid; A second homogenizing reaction tank is used to perform a second pH adjustment and a second coagulation treatment on the remaining solution after the solid humic acid is extracted; and The second solid-liquid separation equipment is used to separate the solid and liquid of the mud-water mixture after the second coagulation treatment.

[0006] Further preferably, the filter box comprises: A box body, wherein an inclined channel is provided in the box body, the organic nanofiltration membrane is fixedly arranged in the inclined channel, and the lower end of the inclined channel is connected to a water production space for receiving a solution passing through the organic nanofiltration membrane and a storage space for receiving a solution intercepted by the organic nanofiltration membrane; A feed pipe connected to the upper end of the inclined channel; A discharge pipe connected to the water production space for discharging the solution in the water production space; A pressure valve, fixedly installed in the material storage space and located at a side of the material storage space away from the inclined channel and controlled to switch based on the pressure of the solution in the material storage space; a switch valve, which is fixedly installed in the material storage space and is located at a communication position between the inclined channel and the material storage space and is switched based on the switching of the pressure valve, wherein the pressure valve and the switch valve are switched differently; and A discharge pipe is connected to the pressure valve.

[0007] Further preferably, the organic nanofiltration membrane is arranged along the inclined direction of the inclined channel, and the inclination angle of the organic nanofiltration membrane to the horizontal direction is less than 45°.

[0008] Further preferably, a plurality of supporting ribs for supporting the organic nanofiltration membrane are fixedly provided in the inclined channel.

[0009] Further preferably, the support ribs are wavy along the inclination direction of the inclined channel.

[0010] Further preferably, the first homogeneous reaction tank and the second homogeneous reaction tank both include: A cell body is provided with a processing space, and the cell body is connected with a feed connection pipe for receiving a solution to be processed and a discharge connection pipe for discharging a processed product; A first regulator metering pump, used to add a pH regulator into the processing space, wherein the start and stop of the first regulator metering pump is controlled based on the pH value of the solution in the processing space; a coagulant metering pump, used for adding coagulant into the processing space; a stirring member, for stirring the solution in the processing space; and The driving source provides a rotational driving force for the stirring member and can drive the stirring member to rise and fall.

[0011] It is further preferred that the discharge connecting pipe in the first homogenizing reaction tank is connected to a second regulator metering pump for adding a pH regulator into the pipe.

[0012] Further preferably, a movable disk is provided in the processing space so as to move up and down, a rotating disk is rotatably mounted on the movable disk, a lifting shaft is fixedly connected to the rotating disk, one end of the lifting shaft away from the rotating disk is dynamically connected to the driving source, and the driving source can drive the lifting shaft to lift and lower to realize the lifting and lowering of the rotating disk and the movable disk; A first through hole is opened in the rotating disk and penetrates up and down, and a second through hole is opened in the moving disk and penetrates up and down.

[0013] Further preferably, a detector for monitoring the transparency of the solution in the processing space is fixedly connected to the lower end of the movable plate, and the detector is electrically connected to the driving source.

[0014] The present application also provides a treatment process based on the above-mentioned landfill leachate concentrate treatment system, comprising the following process steps: S1: The concentrated leachate to be treated enters the filter box for filtration to obtain a solution filtered by an organic nanofiltration membrane and a solution intercepted by an organic nanofiltration membrane; If the solution filtered by the organic nanofiltration membrane meets the discharge standard, it will be discharged directly. If it does not meet the standard, it will be returned for re-filtration. The solution intercepted by the organic nanofiltration membrane enters the first homogenization reaction tank; S2: PH adjustment and coagulation treatment are performed in the first homogenization reaction tank, and the mixture is stirred evenly. After standing for 2-3 hours, the bottom mud-water mixture and the upper solution are obtained; wherein the pH in the first homogenizing reaction tank is adjusted to 1.5-2.0; The dosage of coagulant is 1000-3000ppm and is added continuously and evenly; S3: sending the bottom mud-water mixture obtained in step S2 to the first solid-liquid separation device, and adding a pH regulator to the mud-water mixture during the transportation process to adjust the pH to 4.0-5.0, and the upper layer solution is returned for re-filtration; S4: The first solid-liquid separation device performs solid-liquid separation on the mud-water mixture and obtains the separated solid humic acid and liquid solution; S5: sending the liquid solution obtained in step S4 into a second homogenizing reaction tank, performing pH adjustment and coagulation treatment in the second homogenizing reaction tank and stirring the solution uniformly, and obtaining a bottom mud-water mixture and an upper solution after standing for 2-3 hours; wherein the pH in the second homogenizing reaction tank is adjusted to 8.0-8.5; The dosage of coagulant is 500-2000ppm and is added continuously and evenly; S6: returning the upper layer solution obtained in step S5 for re-filtration, sending the bottom mud-water mixture obtained in step S5 to a second solid-liquid separation device for solid-liquid separation, and obtaining the separated solid sludge and liquid solution; S7: The solid sludge obtained in step S6 is transported out for treatment, and the liquid solution obtained in step S6 is returned for re-filtration treatment.

[0015] In summary, the present application includes at least the following beneficial effects: 1. An organic nanofiltration membrane is installed in the filter box to filter the concentrated water of the landfill leachate, reduce the processing volume of subsequent steps, and save energy and reagent consumption.

[0016] 2. The humic acid products produced in the treatment process can be used as fertilizers to improve the recycling rate of wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a system block diagram of a concentrated water treatment system for leachate from a domestic waste landfill; Figure 2 is a vertical cross-sectional schematic diagram of the filter box; Figure 3 1 is a vertical cross-sectional schematic diagram of the first homogeneous reaction tank / the second homogeneous reaction tank; Figure 4 The present invention is a process flow chart of a concentrated water treatment process of leachate from a domestic waste landfill.

[0018] Description of reference numerals: 1. Box body; 2. Feed pipe; 3. Inclined channel; 4. Support ribs; 5. Organic nanofiltration membrane; 6. Switch valve; 7. Storage space; 8. Pressure valve; 9. Water production space; 10. Discharge pipe; 11. Discharge pipe; 12. Support frame; 13. Drive source; 14. Feed connecting pipe; 15. First regulator metering pump; 16. Discharge connecting pipe; 17. Coagulant metering pump; 18. Stirring element; 19. Lifting shaft; 20. Pool body; 21. Detector; 22. Processing space; 23. First through hole; 24. Rotating disk; 25. Moving disk; 26. Second through hole. DETAILED DESCRIPTION

[0019] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0020] In the present invention, unless otherwise stated, the directional words such as "upper" and "lower" usually refer to the orientation in the assembled state. "Inside" and "outside" refer to the inside and outside relative to the outline of each component itself.

[0021] The present invention discloses a system for treating concentrated water from leachate from a domestic waste landfill. Figure 1 As shown, a filter box, a first homogenizing reaction tank, a first solid-liquid separation device, a second homogenizing reaction tank, and a second solid-liquid separation device are sequentially arranged along the processing sequence. Among them, the first solid-liquid separation device and the second solid-liquid separation device can adopt common gravity (sedimentation) separation equipment, centrifugal separation equipment, filter screen separation equipment, etc.

[0022] An organic nanofiltration membrane 5 is provided in the filter box for filtering and reducing the concentrated water of the leachate. Based on the selective permeability of the organic nanofiltration membrane 5, the water molecules and monovalent ions in the wastewater can pass through the organic nanofiltration membrane 5, while the remaining organic matter and divalent ions in the wastewater are intercepted by the organic nanofiltration membrane 5. In the actual filtration process, the side that passes through the organic nanofiltration membrane 5 is called the water production side, and the other side is called the concentrated water side. Most of the water molecules and monovalent ions in the wastewater pass through the organic nanofiltration membrane 5 and are located on the water production side, while organic matter, divalent ions and a small part of water molecules are enriched and concentrated on the concentrated water side, thereby achieving the reduction of the wastewater volume on the concentrated water side, reducing the processing pressure of the subsequent treatment process, and thus saving energy consumption and the amount of reagents used.

[0023] The first homogenization reaction tank performs the first pH adjustment and the first coagulation treatment on the wastewater after the reduction. The first solid-liquid separation equipment performs solid-liquid separation on the mud-water mixture after the first coagulation treatment and extracts solid humic acid. The second homogenization reaction tank performs the second pH adjustment and the second coagulation treatment on the residual solution after the solid humic acid is extracted. The second solid-liquid separation equipment performs solid-liquid separation on the mud-water mixture after the second coagulation treatment.

[0024] Specifically, in combination with Figure 2 The filter box includes a box body 1, a feed pipe 2, a discharge pipe 10, a pressure valve 8, a switch valve 6 and a discharge pipe 11.

[0025] Among them, an inclined channel 3 is opened in the box body 1, and the organic nanofiltration membrane 5 is fixedly arranged in the inclined channel 3. The lower end of the inclined channel 3 is connected with a water production space 9 for receiving the solution passing through the organic nanofiltration membrane 5 and a storage space 7 for receiving the solution intercepted by the organic nanofiltration membrane 5. In this embodiment, the setting of the inclined channel 3 enables the wastewater to be treated to flow along the inclined channel 3 under the action of gravity and be filtered and treated under the action of the organic nanofiltration membrane 5 without providing additional liquid flow driving force.

[0026] The feed pipe 2 is connected to the upper starting end of the inclined channel 3 , and the wastewater to be treated enters the inclined channel 3 through the feed pipe 2 .

[0027] The discharge pipe 10 is connected to the water production space 9 and is used to discharge the solution in the water production space 9. It should be noted that wastewater discharge generally has a discharge standard, so a wastewater detector (not shown) needs to be set in the water production space 9 to detect the solution in the water production space 9. If the solution in the water production space 9 meets the discharge standard, the solution in the water production space 9 can be discharged through the discharge pipe 10; if the solution in the water production space 9 does not meet the discharge standard, the discharge pipe 10 needs to discharge the solution in the water production space 9 to other wastewater treatment systems for further treatment, or discharge the solution in the water production space 9 into the feed pipe 2 and return it to the filter box for treatment.

[0028] In summary, the end of the discharge pipe 10 away from the water production space 9 can be connected to a wastewater discharge system that controls the discharge destination of wastewater based on the solution detection results in the water production space 9. In this embodiment, the discharge pipe 10 and the feed pipe 2 are connected. If the solution in the water production space 9 does not meet the discharge standard, the solution in the water production space 9 is returned to the filter box through the discharge pipe 10 and the feed pipe 2 for treatment.

[0029] The pressure valve 8 is fixedly installed in the discharge space and located at the side of the storage space 7 away from the inclined channel 3 and is switched based on the pressure of the solution in the storage space 7. The switch valve 6 is fixedly installed in the storage space 7 and located at the communication position between the inclined channel 3 and the storage space 7 and is switched based on the switch of the pressure valve 8. The pressure valve 8 is switched differently from the switch valve 6. The discharge pipe 11 is connected to the pressure valve 8.

[0030] Since the switch valve 6 and the pressure valve 8 are switched differently and the switch valve 6 is installed at the communication position between the storage space 7 and the inclined channel 3, the storage space 7 can be connected with the inclined channel 3 only after the switch valve 6 is opened. Therefore, when the switch valve 6 is opened and the pressure valve 8 is closed, the wastewater intercepted by the organic nanofiltration membrane 5 will enter the storage space 7 for storage until the pressure exerted by the solution in the storage space 7 on the pressure valve 8 reaches the threshold of the pressure valve 8. That is, when the solution in the storage space 7 reaches a certain amount, the pressure valve 8 is opened, the switch valve 6 is closed, and the solution in the storage space 7 is discharged from the filter box through the discharge pipe 11.

[0031] Without considering the measurement accuracy of the valve, the linkage setting of the pressure valve 8 and the switch valve 6 can control the amount of solution discharged from the discharge pipe 11 each time to be consistent, which is convenient for the control of the processing volume of the subsequent processing process. In addition, the filtering process generally takes a long time. When the amount of solution in the storage space 7 reaches the discharge volume, the subsequent processing equipment of the filter box has completed the processing of the previous batch of solution. Therefore, the control factors of the switch valve 6 and the pressure valve 8 only need to be based on the pressure of the solution in the storage space 7.

[0032] Of course, in some other special cases, the subsequent processing equipment and processing process of the filter box take longer. That is, when the amount of solution in the storage space 7 has reached the discharge amount (the solution pressure has reached the threshold set by the pressure valve 8), the subsequent processing equipment of the filter box has not yet finished processing the previous round of solution. At this time, the switch valve 6 and the pressure valve 8 are still controlled based on whether the subsequent processing equipment of the filter box is in the processing state.

[0033] In some embodiments, the organic nanofiltration membrane 5 is arranged along the inclined direction of the inclined channel 3, and the inclination angle of the organic nanofiltration membrane 5 to the horizontal direction is less than 45°, so as to avoid the wastewater to be treated flowing too fast to affect the filtering effect.

[0034] In some embodiments, a plurality of support ribs 4 for supporting the organic nanofiltration membrane 5 are fixedly provided in the inclined channel 3. The provision of the support ribs 4 is conducive to improving the strength of the organic nanofiltration membrane 5, and the use of rib strips can also avoid occupying too much area of ​​the organic nanofiltration membrane 5 and affecting the filtering effect.

[0035] In some embodiments, the support ribs 4 are wavy along the inclined direction of the inclined channel 3, so that the organic nanofiltration membrane 5 is also wavy along the inclined direction of the inclined channel 3, further reducing the flow rate of the wastewater to be treated, prolonging the contact time between the wastewater and the organic nanofiltration membrane 5, and improving the filtering effect. In this embodiment, the degree of filtration of the wastewater to be treated by the organic nanofiltration membrane 5 is 75% to 80%. That is, the amount of water produced by the organic nanofiltration membrane 5 accounts for 75% to 80% of the total amount of treatment, and the amount of wastewater intercepted by the organic nanofiltration membrane 5 accounts for 20% to 25% of the total amount of treatment.

[0036] In a further embodiment, in combination with Figure 3 As shown, the first homogenizing reaction tank and the second homogenizing reaction tank both include a tank body 20 , a first regulating metering pump, a coagulant metering pump 17 , a stirring element 18 and a driving source 13 .

[0037] Specifically, a processing space 22 is provided in the tank body 20, and a feed connection pipe 14 for receiving the solution to be treated and a discharge connection pipe 16 for discharging the treated product are connected to the tank body 20. According to the processing sequence, the feed connection pipe 14 on the first homogenizing reaction tank is connected to the discharge pipe in the filter box, and the feed connection pipe 14 on the second homogenizing reaction tank is connected to the first solid-liquid separation device.

[0038] The first regulator metering pump 15 is used to add a pH regulator into the processing space 22. The pH regulator may be an acidic substance such as hydrochloric acid or sulfuric acid. The start and stop of the first regulator metering pump 15 is controlled based on the pH value of the solution in the processing space 22. Specifically, a pH detection sensor (not shown) is provided in the processing space 22, and the start and stop of the first regulator metering pump 15 is controlled based on the detection result of the sensor.

[0039] The coagulant metering pump 17 is used to add coagulant into the processing space 22. The coagulant is generally ferric chloride, polyferric PFS or other coagulant agents, and the addition process of the coagulant metering pump 17 is a continuous and uniform process to ensure uniform coagulation effect.

[0040] The stirring element 18 is used to stir the solution in the treatment space 22, thereby improving the pH adjustment and coagulation speed and accelerating the treatment efficiency.

[0041] The driving source 13 provides a rotational driving force for the stirring member 18 and can drive the stirring member 18 to rise and fall. Specifically, the driving source 13 is an integrated driving system of rotational drive and lifting drive, which can not only provide a rotational driving force for the stirring member 18, but also drive the stirring member 18 to rise and fall so as to be conveniently removed from the processing space 22 for cleaning and maintenance. In this embodiment, a support frame 12 is provided outside the pool body 20 for hoisting the driving source 13, so that the driving source 13 is located at the top of the pool body 20 to facilitate the driving and lifting of the stirring member 18.

[0042] In some embodiments, a moving disk 25 is provided in the processing space 22 so as to move up and down, a rotating disk 24 is rotatably mounted on the moving disk 25, a lifting shaft 19 is fixedly connected to the rotating disk 24, and one end of the lifting shaft 19 away from the rotating disk 24 is dynamically connected to the driving source 13, and the driving source 13 can drive the lifting shaft 19 to lift and lower to achieve the lifting and lowering of the rotating disk 24 and the moving disk 25. A first through hole 23 is provided in the rotating disk 24 so as to pass through it from top to bottom, and a second through hole 26 is provided in the moving disk 25 so as to pass through it from top to bottom. When the rotating disk 24 is driven by the driving source 13 to rotate relative to the moving disk 25 so that the first through hole 23 and the second through hole 26 are connected, the stirring member 18 can move downward under the drive of the driving source 13 and pass through the first through hole 23 and the second through hole 26 and be located in the processing space 22 to stir the solution.

[0043] In some embodiments, a detector 21 for monitoring the transparency of the solution in the processing space 22 is fixedly connected to the lower end of the movable disk 25. The driving source 13 drives the rotating disk 24 and the movable disk 25 to rise and fall, and the transparency of the solution in the processing space 22 at different water levels is detected by the detector 21. When the detector 21 detects the water level at which the transparency suddenly changes, the driving source 13 stops driving the rotating disk 24 and the movable disk 25 to rise and fall. At this time, the position of the rotating disk 24 and the movable disk 25 is the boundary position between the upper solution and the bottom mud-water mixture in the processing space 22. At this time, the driving source 13 drives the rotating disk 24 to rotate, so that the first through hole 23 and the second through hole 26 are staggered, thereby separating the upper solution and the bottom mud-water mixture from top to bottom. At this time, the discharge connecting pipe 16 can discharge the mud-water mixture to the solid-liquid separation equipment. Specifically, the discharge connecting pipe 16 in the first homogeneous reaction tank discharges the muddy-water mixture in the first homogeneous reaction tank to the first solid-liquid separation device, and the discharge connecting pipe 16 in the second homogeneous reaction tank discharges the muddy-water mixture in the second homogeneous reaction tank to the second solid-liquid separation device.

[0044] After the mud-water mixture in the treatment space 22 is discharged, the driving source 13 drives the rotating disk 24 to rotate so that the first through hole 23 and the second through hole 26 are connected, so that the upper solution in the treatment space 22 can be discharged through the discharge connecting pipe 16. The discharge destination of the upper solution can be direct discharge, or returned to the feed pipe 2 of the filter box, or discharged to other wastewater treatment systems. In this embodiment, the upper solution needs to be returned to the feed pipe 2 of the filter box and re-filtered. Therefore, a discharge system that switches the discharge path based on the type of discharge needs to be set at the end of the discharge connecting pipe 16.

[0045] In a further embodiment, the discharge connection pipe 16 in the first homogenization reaction tank is connected to a second regulator metering pump (not shown) for adding a pH regulator into the pipe. Specifically, the second regulator metering pump is provided on the discharge connection pipe 16 to add regulators such as caustic soda flakes or lime solution into the pipe, which is beneficial to the extraction of humic acid products in the solution on the one hand, and makes the pH of the solution closer to neutral on the other hand, reducing corrosion to equipment and pipelines.

[0046] The steps of using a system for treating concentrated water from a landfill leachate of domestic waste in the present invention are as follows: First, the wastewater to be treated enters the filter box through the feed pipe 2, and the wastewater is filtered through the organic nanofiltration membrane 5. The solution passing through the organic nanofiltration membrane 5 enters the water production space 9 and is discharged accordingly after detection; the solution intercepted by the organic nanofiltration membrane 5 enters the storage space 7.

[0047] Secondly, when the solution in the storage space 7 reaches a certain amount, the pressure valve 8 opens and discharges the solution into the first homogenization reaction tank for pH adjustment, coagulation and static sedimentation; Again, the driving source 13 drives the rotating disk 24 and the moving disk 25 at the first homogeneous reaction tank to descend, and separates the upper solution and the bottom mud-water mixture in the processing space 22 of the first homogeneous reaction tank, and discharges the mud-water mixture to the first solid-liquid separation device through the discharge connecting pipe 16. The pH of the solution is adjusted during the discharge of the mud-water mixture from the first homogeneous reaction tank to the first solid-liquid separation device. When the mud-water mixture is completely discharged from the first homogeneous reaction tank, the driving source 13 drives the rotating disk 24 at the first homogeneous reaction tank to rotate so that the first through hole 23 and the second through hole 26 are connected, and the discharge connecting pipe 16 discharges the upper solution.

[0048] Then, the first solid-liquid separation equipment performs solid-liquid separation on the mud-water mixture to obtain solid humic acid and a liquid solution. The solid humic acid can be used as a fertilizer, and the liquid solution is discharged into the second homogenization reaction tank.

[0049] Then, pH adjustment, coagulation and static sedimentation are performed in the second homogeneous reaction tank, and the driving source 13 drives the rotating disk 24 and the moving disk 25 at the second homogeneous reaction tank to descend, and separates the upper solution and the bottom mud-water mixture in the processing space 22 of the second homogeneous reaction tank, and discharges the mud-water mixture to the second solid-liquid separation device through the discharge connecting pipe 16. When the mud-water mixture is completely discharged from the second homogeneous reaction tank, the driving source 13 drives the rotating disk 24 at the second homogeneous reaction tank to rotate so that the first through hole 23 and the second through hole 26 are connected, and the discharge connecting pipe 16 discharges the upper solution.

[0050] Finally, the second solid-liquid separation equipment performs solid-liquid separation on the mud-water mixture to obtain solid sludge and liquid solution. The solid sludge is transported out for treatment, and the liquid solution is directly discharged or returned to the feed pipe 2 of the filter box or other wastewater treatment systems.

[0051] The present invention also provides a treatment process based on the above-mentioned landfill leachate concentrated water treatment system, combined with the attached Figure 4 , including the following process steps: S1: The concentrated leachate to be treated enters the filter box for filtration to obtain a solution filtered by the organic nanofiltration membrane 5 and a solution intercepted by the organic nanofiltration membrane 5; If the solution filtered by the organic nanofiltration membrane 5 meets the discharge standard, it is directly discharged; if it does not meet the standard, it is returned for re-filtration; The solution intercepted by the organic nanofiltration membrane 5 enters the first homogenization reaction tank; S2: PH adjustment and coagulation treatment are performed in the first homogenization reaction tank, and the mixture is stirred evenly. After standing for 2-3 hours, the bottom mud-water mixture and the upper solution are obtained; wherein the pH in the first homogenizing reaction tank is adjusted to 1.5-2.0; The dosage of coagulant is 1000-3000ppm and is added continuously and evenly; S3: sending the bottom mud-water mixture obtained in step S2 to the first solid-liquid separation device, and adding a pH regulator to the mud-water mixture during the transportation process to adjust the pH to 4.0-5.0, and the upper layer solution is returned for re-filtration; S4: The first solid-liquid separation device performs solid-liquid separation on the mud-water mixture and obtains the separated solid humic acid and liquid solution; S5: sending the liquid solution obtained in step S4 into a second homogenizing reaction tank, performing pH adjustment and coagulation treatment in the second homogenizing reaction tank and stirring the solution uniformly, and obtaining a bottom mud-water mixture and an upper solution after standing for 2-3 hours; wherein the pH in the second homogenizing reaction tank is adjusted to 8.0-8.5; The dosage of coagulant is 500-2000ppm and is added continuously and evenly; S6: returning the upper layer solution obtained in step S5 for re-filtration, sending the bottom mud-water mixture obtained in step S5 to a second solid-liquid separation device for solid-liquid separation, and obtaining the separated solid sludge and liquid solution; S7: The solid sludge obtained in step S6 is transported out for treatment, and the liquid solution obtained in step S6 is returned for re-filtration treatment.

[0052] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0053] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0054] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A system for treating concentrated water from leachate from a domestic waste landfill, characterized in that: Set in the processing order: A filter box, with a built-in organic nanofiltration membrane (5) for reducing the amount of concentrated leachate; The first homogenization reaction tank is used to perform the first pH adjustment and the first coagulation treatment on the reduced wastewater; The first solid-liquid separation equipment performs solid-liquid separation on the mud-water mixture after the first coagulation treatment and extracts solid humic acid; The second homogenization reaction tank is used to perform a second pH adjustment and a second coagulation treatment on the remaining solution after the solid humic acid is extracted; as well as The second solid-liquid separation equipment is used to separate the solid and liquid of the mud-water mixture after the second coagulation treatment.

2. The system for treating concentrated water from leachate from a domestic waste landfill according to claim 1, characterized in that: The filter box comprises: A box body (1), wherein an inclined channel (3) is provided in the box body (1), the organic nanofiltration membrane (5) is fixedly arranged in the inclined channel (3), and the lower end of the inclined channel (3) is connected to a water production space (9) for receiving a solution passing through the organic nanofiltration membrane (5) and a material storage space (7) for receiving a solution intercepted by the organic nanofiltration membrane (5); A feed pipe (2) connected to the upper starting end of the inclined channel (3); A discharge pipe (10) connected to the water production space (9) and used for discharging the solution in the water production space (9); A pressure valve (8) is fixedly installed in the storage space (7) and is located on a side of the storage space (7) away from the inclined channel (3) and is controlled to switch based on the pressure of the solution in the storage space (7); an on-off valve (6) fixedly installed in the material storage space (7) and located at a position where the inclined channel (3) and the material storage space (7) are connected and is switched based on the switching of the pressure valve (8), wherein the pressure valve (8) and the on-off valve (6) are switched differently; and The discharge pipe (11) is connected to the pressure valve (8).

3. The system for treating concentrated water from leachate from a domestic waste landfill according to claim 2, characterized in that: The organic nanofiltration membrane (5) is arranged along the inclined direction of the inclined channel (3), and the inclination angle of the organic nanofiltration membrane (5) to the horizontal direction is less than 45°.

4. The system for treating concentrated water from leachate from a domestic waste landfill according to claim 2, characterized in that: A plurality of support ribs (4) for supporting the organic nanofiltration membrane (5) are fixedly disposed in the inclined channel (3).

5. The system for treating concentrated water from leachate from a domestic waste landfill according to claim 4, characterized in that: The supporting ribs (4) are wavy in shape along the inclination direction of the inclined channel (3).

6. The system for treating concentrated water from leachate from a domestic waste landfill according to any one of claims 1 to 5, characterized in that: The first homogenous reaction tank and the second homogenous reaction tank both include: A cell body (20) having a processing space (22) formed therein, the cell body (20) being connected to a feed connection pipe (14) for receiving a solution to be processed and a discharge connection pipe (16) for discharging a processed product; A first regulator metering pump (15) is used to add a pH regulator into the processing space (22), wherein the start and stop of the first regulator metering pump (15) is controlled based on the pH value of the solution in the processing space (22); A coagulant metering pump (17) for adding coagulant into the processing space (22); a stirring member (18) for stirring the solution in the processing space (22); and The driving source (13) provides a rotational driving force for the stirring member (18) and is capable of driving the stirring member (18) to move up and down.

7. The system for treating concentrated water from leachate from a domestic waste landfill according to claim 6, characterized in that: The discharge connecting pipe (16) in the first homogenizing reaction tank is connected to a second regulator metering pump for adding a pH regulator into the pipe.

8. The system for treating concentrated water from leachate from a domestic waste landfill according to claim 5, characterized in that: A movable disk (25) is provided in the processing space (22) so as to move up and down, a rotating disk (24) is rotatably mounted on the movable disk (25), a lifting shaft (19) is fixedly connected to the rotating disk (24), one end of the lifting shaft (19) away from the rotating disk (24) is dynamically connected to the driving source (13), and the driving source (13) can drive the lifting shaft (19) to move up and down to realize the lifting and lowering of the rotating disk (24) and the movable disk (25); The rotating disk (24) is provided with a first through hole (23) extending vertically therethrough, and the moving disk (25) is provided with a second through hole (26) extending vertically therethrough.

9. The system for treating concentrated water from leachate from a domestic waste landfill according to claim 8, characterized in that: A detector (21) for monitoring the transparency of the solution in the processing space (22) is fixedly connected to the lower end of the movable plate (25), and the detector (21) is electrically connected to the driving source (13).

10. A process for treating concentrated water from leachate from a domestic waste landfill according to any one of claims 1 to 9, characterized in that: The process steps include: S1: The concentrated leachate to be treated enters the filter box for filtration to obtain a solution filtered by the organic nanofiltration membrane (5) and a solution intercepted by the organic nanofiltration membrane (5); If the solution filtered by the organic nanofiltration membrane (5) meets the discharge standard, it is directly discharged; if it does not meet the standard, it is returned for re-filtration; The solution intercepted by the organic nanofiltration membrane (5) enters the first homogenization reaction tank; S2: PH adjustment and coagulation treatment are performed in the first homogenization reaction tank, and the mixture is stirred evenly. After standing for 2-3 hours, the bottom mud-water mixture and the upper solution are obtained; wherein the pH in the first homogenizing reaction tank is adjusted to 1.5-2.0; The dosage of coagulant is 1000-3000ppm and is added continuously and evenly; S3: sending the bottom mud-water mixture obtained in step S2 to the first solid-liquid separation device, and adding a pH regulator to the mud-water mixture during the transportation process to adjust the pH to 4.0-5.0, and the upper layer solution is returned for re-filtration; S4: The first solid-liquid separation device performs solid-liquid separation on the mud-water mixture and obtains the separated solid humic acid and liquid solution; S5: sending the liquid solution obtained in step S4 into a second homogenizing reaction tank, performing pH adjustment and coagulation treatment in the second homogenizing reaction tank and stirring the solution uniformly, and obtaining a bottom mud-water mixture and an upper solution after standing for 2-3 hours; wherein the pH in the second homogenizing reaction tank is adjusted to 8.0-8.5; The dosage of coagulant is 500-2000ppm and is added continuously and evenly; S6: returning the upper layer solution obtained in step S5 for re-filtration, sending the bottom mud-water mixture obtained in step S5 to a second solid-liquid separation device for solid-liquid separation, and obtaining the separated solid sludge and liquid solution; S7: The solid sludge obtained in step S6 is transported out for treatment, and the liquid solution obtained in step S6 is returned for re-filtration treatment.

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