CN114620887A - A landfill leachate treatment system and process - Google Patents

Abstract

The invention provides a landfill leachate treatment system and process, comprising a grid tank, a regulating tank, an anaerobic tank, a denitrification tank, a nitrification tank and an ultrafiltration membrane tank which are connected in sequence, and an ultrafiltration membrane is arranged in the ultrafiltration membrane tank , the liquid outlet end of the ultrafiltration membrane tank is connected to the ultrafiltration clean water tank, the liquid outlet end of the ultrafiltration clean water tank is connected to the advanced treatment device, the sludge discharge port of the anaerobic tank, the sludge discharge port of the ultrafiltration membrane tank and the depth The sludge discharge ports of the treatment device are all connected to the sludge thickening tank, the anaerobic tank is cylindrical, the denitrification tank and the nitrification tank are distributed around the outer wall of the anaerobic tank, the anaerobic tank is surrounded in the center, and the anaerobic tank is anaerobic. The oxygen tank, denitrification tank and nitrification tank are all steel structures. The invention has compact overall structure and small footprint, and the leachate in the anaerobic tank can directly utilize the heat generated by the nitrification tank, thereby maintaining a mesothermal anaerobic state. heat, the whole system runs stably and reliably.

Description

A landfill leachate treatment system and process

technical field

The invention belongs to the technical field of wastewater treatment, and more particularly, particularly relates to a landfill leachate treatment system and process.

Background technique

Landfill leachate refers to the moisture contained in the garbage itself in the landfill, the rain and snow water and other moisture entering the landfill, deducting the saturated water holding capacity of the garbage and the overburden, and formed through the garbage layer and the overburden. A high concentration of organic waste water. There is also moisture leaking from accumulated garbage ready for incineration.

The treatment methods of landfill leachate include physical and chemical methods and biological methods. The physical and chemical methods mainly include activated carbon adsorption, chemical precipitation, density separation, chemical oxidation, chemical reduction, ion exchange, membrane dialysis, gas and wet oxidation and other methods. The COD removal rate can reach 50% to 87%. Compared with biological treatment, physicochemical treatment is not affected by changes in water quality and quantity, and the effluent quality is relatively stable, especially for landfill leachate with a low BOD5/COD ratio (0.07-0.20), which is difficult to biologically treat, and has a better treatment effect.

Biological methods are divided into aerobic biological treatment, anaerobic biological treatment and the combination of the two. Aerobic treatment includes activated sludge method, aeration oxidation tank, aerobic stabilization pond, biological turntable and trickling filter. Anaerobic treatment includes upward flow sludge bed, anaerobic immobilized bioreactor, mixed reactor and anaerobic stabilization pond.

However, most of the traditional landfill leachate treatment equipment and processes have poor treatment capacity and low efficiency, and the COD, ammonia nitrogen and total phosphorus of the effluent water quality cannot meet the discharge standards or have secondary pollution. It is an urgent problem to be solved in the process of landfill treatment to research and explore efficient, economical, and landfill leachate treatment processes and devices that meet the new emission standards.

SUMMARY OF THE INVENTION

In view of this, one of the objectives of the present invention is to provide a landfill leachate treatment system with compact structure and high treatment effect, so as to solve the problems existing in the prior art.

For achieving the above object, the technical scheme of the present invention is:

A landfill leachate treatment system, comprising a grid tank, a regulating tank, an anaerobic tank, a denitrification tank, a nitrification tank and an ultrafiltration membrane tank which are connected in sequence, wherein an ultrafiltration membrane is arranged in the ultrafiltration membrane tank, and the ultrafiltration membrane is arranged in the ultrafiltration membrane tank. The liquid outlet end of the ultrafiltration membrane tank is connected to the ultrafiltration clean water tank, the liquid outlet end of the ultrafiltration clean water tank is connected to the advanced treatment device, and the sludge discharge port of the anaerobic tank and the sewage of the ultrafiltration membrane tank are connected. The sludge discharge port and the sludge discharge port of the advanced treatment device are both connected to the sludge concentration tank, the nitrification tank and the ultrafiltration membrane tank are both provided with an aeration device, and the liquid outlet end of the anaerobic tank A liquid return pipeline is arranged between the regulating tank and the sludge discharge end of the ultrafiltration membrane tank and a sludge mixed liquid return pipeline is arranged between the sludge discharge end of the ultrafiltration membrane tank and the denitrification tank. A backwash pipeline is also connected between the ultrafiltration membrane tanks, the anaerobic tank is cylindrical, the denitrification tank and the nitrification tank are distributed around the outer side wall of the anaerobic tank, and the anaerobic tank is divided into It is surrounded by the center, and the anaerobic tank, the denitrification tank and the nitrification tank are all steel structures.

Further, the advanced treatment device includes a pipeline mixer, a flocculation sedimentation tank, an intermediate water tank, an ozone oxidation tower, a filter tank and a clean water tank that are connected in sequence, and the liquid outlet end of the ultrafiltration clean water tank is connected to the pipeline mixer. The liquid inlet end of the flocculation and sedimentation tank is connected, a flocculant is added to the pipeline mixer, an ozone generator is connected to the ozone oxidation tower, and the bottom of the flocculation sedimentation tank is communicated with the sludge concentration tank through the sludge discharge port.

Further, the pipeline mixers are arranged in two and connected in series; the flocculation sedimentation tank is a central vertical flow sedimentation tank with an inclined tube in the middle.

Further, the volume ratio of the denitrification tank, the anaerobic tank and the nitrification tank is 1:1.9-2.3:1.5-1.7.

Further, the ultrafiltration membrane is cylindrical, the ultrafiltration membrane tank is also provided with a mounting plate, a drive motor, and a backwash assembly, the bottom of the ultrafiltration membrane is open, and the seal is detachably installed on the ultrafiltration membrane. On the mounting plate, the backwashing assembly includes a transmission shaft, a lateral backwashing branch pipe, a longitudinal branching pipe for backwashing, a rotary joint and a high-pressure nozzle, the transmission shaft is located in the center of the ultrafiltration membrane, and the bottom passes through the mounting plate and is connected to the high-pressure nozzle. The drive motor is connected by transmission, the backwashing lateral branch pipe is connected at intervals on the transmission shaft located inside the ultrafiltration membrane, and the backwashing lateral branch pipe at the uppermost end is connected to the backwashing pipeline through the rotary joint. The backwashing transverse branch pipe close to one end of the inner wall of the ultrafiltration membrane is communicated with the backwashing longitudinal branch pipe, and a plurality of the high-pressure nozzles are installed in an array on the backwashing longitudinal branch pipe.

Further, the backwashing assembly further includes a brush holder shaft and a cleaning brush. One end of the brush holder shafts is connected to the circumferential side wall of the transmission shaft, and the other end is connected to the cleaning brush. The brush is in contact with the inner wall of the ultrafiltration membrane.

Further, the brush holder shaft includes a first connecting shaft and a second connecting shaft, the first connecting shaft is connected with the transmission shaft, and one end of the second connecting shaft is movably sleeved on the first connecting shaft The other end is connected with the cleaning brush, the first connecting shaft is also sleeved with a spring, and the two ends of the spring are respectively connected with the transmission shaft and the second connecting shaft.

The second object of the present invention is to provide a process for treating landfill leachate, comprising the following steps:

1) Pass the landfill leachate through the grid to remove the floating and suspended matter in the leachate;

2) The leachate after passing through the grid net is collected into the adjustment tank, and the sediment is removed by precipitation;

3) transporting the precipitated leachate in the regulating tank to the anaerobic tank for anaerobic reaction to obtain the effluent and sludge of the anaerobic tank, and the sludge is transported to the sludge thickening tank;

4) The effluent part of the anaerobic tank is mixed with the effluent of the regulating tank before entering the anaerobic tank, and the rest of the effluent is transported to the denitrification tank for anoxic reaction;

5) The leachate treated by the denitrification tank is transported to the nitrification tank to carry out aerobic reaction;

6) The leachate treated in the nitrification tank is transported to the ultrafiltration membrane tank, and treated with the ultrafiltration membrane in the ultrafiltration membrane tank to obtain the ultrafiltration effluent and the sludge mixture, and the sludge mixture is partially returned to the reaction chamber. In the nitrification tank, the rest are sent to the sludge thickening tank;

7) After adding flocculant to the pipeline mixer, the ultrafiltration effluent is transported to the flocculation tank, the effluent of the flocculation tank is transported to the ozone oxidation tower for ozone treatment, and the sedimentation of the flocculation tank is transported to the sludge concentration tank. After passing through the filter tank, the effluent can be sent to the clean water tank or discharged outside;

All the sludge transported to the sludge thickening tank is transported to the conditioning box of the screw dehydrator, flocculant is added, and after dehydration, the mud cake and filtrate are obtained, and the obtained filtrate is transported to the conditioning tank again.

Further, the effluent of the regulating tank is transported to the lower end of the anaerobic tank by the anaerobic feed pump, passes through the packing area in the middle of the anaerobic tank through the upward flow through the water distribution device, and flows out through the outlet at the upper end of the anaerobic tank. The height is 2-4m.

Further, the filler includes the following components in parts by weight: 30-40 parts of corncob, 10-20 parts of fly ash, 60-90 parts of polypropylene hollow microspheres, and 30-45 parts of hydroformyl vinylon silk. The hydroformylated vinylon silk is placed in the polypropylene hollow microspheres.

Compared with the prior art, the present invention has the following beneficial effects:

The system provided by the present invention has a compact overall structure. After the leachate is successively treated by a grid, a regulating tank, an anaerobic tank, a denitrification tank and an ultrafiltration membrane tank, the BOD, ammonia nitrogen, suspended solids, etc. have all reached the discharge standard. , after further advanced treatment, the COD, chroma, total nitrogen and heavy metal content are further reduced to meet the emission standard; the anaerobic tank, denitrification tank and nitrification tank are combined and processed to form an anaerobic tank in the middle. The denitrification tank and the nitrification tank together surround the structure of the anaerobic tank, so that the leachate in the anaerobic tank can directly use the heat generated by the nitrification tank, thereby maintaining the mesophilic anaerobic state, and effectively using the nitrification while ensuring the treatment effect. The heat generated by the pool is stable and reliable.

Description of drawings

FIG. 1 is a schematic flow chart of the landfill leachate treatment system of the present invention.

FIG. 2 is a schematic top view distribution diagram of the anaerobic tank, the nitrification tank and the denitrification tank of the present invention.

FIG. 3 is a schematic flowchart of a deep processing apparatus of the present invention.

Fig. 4 is the structural schematic diagram of the ultrafiltration membrane tank of the present invention.

5 is a schematic structural diagram of the brush holder shaft of the present invention.

In the figure, the corresponding relationship between component names and drawing numbers is:

1. Grille tank; 2. Regulating tank; 3. Anaerobic tank; 4. Denitrification tank; 5. Nitrification tank; 6. Ultrafiltration membrane tank; 7. Ultrafiltration clean water tank; 8. Denitrification mixer; 9. Anaerobic feed pump; 10. Water distribution device; 11. Aeration device; 12. Conditioning box of screw dehydrator; 13. Ultrafiltration membrane; 14. Sludge concentration tank; 15. Liquid return line; 16. Backwash pipe Road; 17, pipeline mixer; 18, flocculation sedimentation tank; 19, intermediate water tank; 20, ozone oxidation tower; 21, filter tank; 22, clean water tank; 23, ozone generator; 24, oxygen tank; 25, installation plate; 26, drive motor; 27, drive shaft; 28, backwash lateral branch pipe; 29, backwash longitudinal branch pipe; 30, rotary joint; 31, high pressure nozzle; 32, brush holder shaft; 32-1, first connecting shaft 32-2, the second connecting shaft; 32-3, the spring; 33, the cleaning brush.

Detailed ways

The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are intended to illustrate the present invention, but not to limit the scope of the present invention.

In the description of the present invention, unless otherwise stated, "plurality" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer" The orientation or positional relationship indicated by , "front end", "rear end", "head", "tail", etc. are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, not An indication or implication that the referred device or element must have a particular orientation, be constructed and operate in a particular orientation, is not to be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc. are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection. Ground connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Example:

As shown in accompanying drawings 1 to 5:

The present invention provides a landfill leachate treatment system, which includes a grid tank 1, a regulating tank 2, an anaerobic tank 3, a denitrification tank 4, a nitrification tank 5 and an ultrafiltration membrane tank 6 which are connected in sequence. An ultrafiltration membrane 13 is provided in the tank 6, the liquid outlet end of the ultrafiltration membrane tank 6 is connected to the ultrafiltration clean water tank 7, and the liquid outlet end of the ultrafiltration clean water tank 7 is connected to the advanced treatment device. The sludge discharge port of the pool 3, the sludge discharge port of the ultrafiltration membrane tank 6 and the sludge discharge port of the advanced treatment device are all connected to the sludge concentration tank 14, the nitrification tank 5 and the ultrafiltration tank 14. The membrane tank 6 is provided with an aeration device 11, a liquid return line 15 is provided between the liquid outlet end of the anaerobic tank 3 and the adjustment tank 2, and the sludge discharge end of the ultrafiltration membrane tank 6 is provided. A sludge mixed liquor return pipeline is arranged between the denitrification tank 4, a backwash pipeline 16 is also connected between the ultrafiltration clear water tank 7 and the ultrafiltration membrane tank 6, and the anaerobic tank is 3 is cylindrical, the denitrification tank 4 and the nitrification tank 5 are distributed around the outer side wall of the anaerobic tank 3, the anaerobic tank 3 is surrounded in the center, and the anaerobic tank 3, the The denitrification tank 4 and the nitrification tank 5 are both of steel structure, which is convenient for heat transfer.

Among them, the grid pool 1 is provided with a two-stage artificial grid net, which can be used to intercept floating objects and larger suspended matter in the leachate. Sediment and other particulate pollutants are removed by precipitation in the adjustment tank 2, and the water quality and quantity can be balanced in the adjustment tank 2, and then the effluent obtained after precipitation is prompted to the anaerobic tank 3 by the anaerobic feed pump 9. This embodiment Among them, the anaerobic tank 3 is a UBF anaerobic tank. After the anaerobic reaction, the COD can be greatly degraded. At the same time, part of the COD that is difficult to biochemically degrade in the leachate can also be hydrolyzed and acidified under anaerobic conditions.

Part of the leachate treated in the anaerobic tank 3 enters the bottom of the anaerobic tank 3 after mixing with the effluent of the regulating tank 2 through the liquid return line 15, and the rest enters the denitrification tank 4 for treatment; In the embodiment, considering that the BOD removal effect of the anaerobic tank 3 is better, it can also be considered that part of the water in the adjustment tank 2 is directly entered into the denitrification tank 4 without the treatment of the anaerobic tank 3. The amount of water is mixed with the effluent of the anaerobic tank 3 and homogenized, so as to achieve the best carbon-nitrogen ratio, so as to ensure the carbon source required in the denitrification tank 4, thereby ensuring the necessary denitrification rate of the system and the stability of the pH value sex. The denitrification tank 4 is in an oxygen-deficient state, and a denitrification mixer 8 can be installed inside to improve the action efficiency of the denitrification bacteria. The effluent of the denitrification tank 4 can flow into the nitrification tank 5 by itself.

In this embodiment, the aeration device 11 in the nitrification tank 5 is a disc jet aeration, and the leachate treated in the nitrification tank 5 can flow into the ultrafiltration membrane tank 6 by self-flow, and in the ultrafiltration membrane tank 6 The sludge and water are separated under the action of the ultrafiltration membrane 13, and the thick sludge produced is partially returned to the denitrification tank through the sludge return pump and the sludge mixed liquid return pipeline.

In the ultrafiltration membrane tank, the aeration system enters the air-water mixing space through the aeration pipe, and the aeration system reaches the membrane part of the ultrafiltration membrane 13 after mixing evenly, so as to ensure that each ultrafiltration membrane evenly obtains Gas scour force. The mixed solution of the ultrafiltration membrane tank continuously flows through the hollow fiber membrane in a cross-flow manner, and continuously brushes the surface of the membrane. Self-flow into the advanced treatment section for further processing. Residual solids, organic particles, microorganisms, etc. cannot pass through the membrane, and are trapped in the liquid mixture, some of which are finally degraded by activated sludge after returning, and some are periodically transported to the sludge thickening tank 14 . The ultrafiltration membrane 13 is chemically cleaned by adding acid and alkali through the membrane backwashing pump and the backwashing pipeline 16 on a regular basis.

3, in this embodiment, the advanced treatment device includes a pipeline mixer 17, a flocculation sedimentation tank 18, an intermediate water tank 19, an ozone oxidation tower 20, a filter tank 21 and a clean water tank 22 that are connected in sequence. The liquid outlet end of the ultrafiltration clear water tank 7 is communicated with the liquid inlet end of the pipeline mixer 17, and a flocculant is added in the pipeline mixer 17. The ozone oxidation tower 20 is connected with an ozone generator 23, and the ozone generation The device 23 is connected with an oxygen tank 24, and the bottom of the flocculation sedimentation tank 18 is communicated with the sludge concentration tank 14 through a sludge discharge port.

Specifically, two pipeline mixers 17 are arranged and connected in series; the flocculation sedimentation tank 18 is a central vertical flow sedimentation tank with an inclined pipe in the middle; The sludge is regularly pumped into the sludge thickening tank 14 . The clean water in the intermediate water tank 19 is pumped into the ozone oxidation tower 20 by a pump, and high-purity ozone (oxygen source) is added through the jet under the action of the jet circulation pump in the ozone catalytic tower 20. Strong oxidizing property, it can directly oxidize and remove refractory pollutants such as residual humic acid and organic nitrogen in wastewater. The effluent of the ozone catalytic tower flows through the filter tank 21 and flows into the clean water tank 22 or is discharged regularly.

In this embodiment, the volume ratio of the denitrification tank, the anaerobic tank and the nitrification tank is 1:1.9-2.3:1.5-1.7. It can basically ensure that the reaction temperature in the anaerobic tank is maintained above 32 °C, and the medium temperature anaerobic state is maintained. Further, in this embodiment, the volume of the denitrification tank is 65m ³ , the volume of the anaerobic tank is 138m ³ , and the volume of the nitrification tank is 108m ³ . The volume of ponds, anaerobic ponds and nitrification ponds can be adjusted adaptively.

In this embodiment, some auxiliary equipment can also be provided, including biochemical cooling device, pH detection device and dissolved oxygen online monitoring device. The heat generated is maintained at about 35°C, but when the extreme temperature is high, the temperature may reach above 38°C, which will have a certain impact on the biochemical treatment. Therefore, when the water temperature exceeds 38°C, it can be stopped. Into the water, start the jet pump and the cooling device for cooling treatment. Since the pool body adopts a steel structure, the heat dissipation is fast, and the water can be restored after the temperature is lowered.

4 and 5, in order to further improve the backwashing efficiency of the ultrafiltration membrane 13 and reduce its replacement cycle, in this embodiment, the ultrafiltration membrane 13 is cylindrical, and the ultrafiltration membrane tank 6 is in the shape of a cylinder. A mounting plate 25, a driving motor 26, and a backwashing assembly are also provided. The bottom of the ultrafiltration membrane 13 is open, and the seal is detachably mounted on the mounting plate 25. The backwashing assembly includes a transmission shaft 27, a reverse Flushing transverse branch pipe 28, backwashing longitudinal branch pipe 29, rotary joint 30 and high pressure nozzle 31, the transmission shaft 27 is located in the center of the ultrafiltration membrane 13 and the bottom is connected to the drive motor 26 through the mounting plate 25. , the drive shaft 27 located inside the ultrafiltration membrane 13 is connected with the backwash lateral branch pipe 28 at intervals, and the backwash lateral branch pipe 28 at the uppermost end is connected to the backwash pipeline 16 through the rotary joint 30 The backwashing lateral branch pipe 28 close to one end of the inner wall of the ultrafiltration membrane 13 is communicated with the backwashing vertical branch pipe 29, and a plurality of the high-pressure nozzles 31 are installed in an array on the backwashing longitudinal branch pipe 29.

The drive motor drives the drive shaft 27 to rotate, and then drives the backwashing lateral branch pipe 28 to rotate around the drive shaft 27, so that the high-pressure nozzle 31 rotates to wash the inner wall of the ultrafiltration membrane 13 to improve the backwashing efficiency.

Further, the backwash assembly also includes a brush holder shaft 32 and a cleaning brush 33. One end of the brush holder shafts 32 is connected to the circumferential side wall of the transmission shaft 27, and the other end is connected to the cleaning brushes. 33. The cleaning brush 33 is in contact with the inner wall of the ultrafiltration membrane 13, and the cleaning brush 33 provided can further scrub the difficult-to-wash sludge attached to the inner wall of the ultrafiltration membrane 13 to avoid long-term accumulation of sludge. Blocking the ultrafiltration membrane 13 can also ensure the filtering effect.

In this embodiment, the brush holder shaft 32 includes a first connecting shaft 32-1 and a second connecting shaft 32-2, the first connecting shaft 32-1 is connected with the transmission shaft 27, and the second connecting shaft 32-1 is connected to the transmission shaft 27. One end of the shaft 32-2 is movably sleeved on the first connecting shaft 32-1, and the other end is connected with the cleaning brush 33. The first connecting shaft 32-1 is also sleeved with a spring 32-3, Two ends of the spring 32-3 are respectively connected to the transmission shaft 27 and the second connection shaft 32-2. By providing the first connecting shaft 32-1, the second connecting shaft 32-2 and the spring 32-3, the cleaning brush 33 can be kept in contact with the inner wall of the ultrafiltration membrane 13, and the cleaning brush 33 can be reduced. wear, thereby prolonging the use time of the cleaning brush 33 .

The present embodiment also provides a process for treating landfill leachate, comprising the following steps:

1) Pass the landfill leachate through the grid to remove the floating and suspended matter in the leachate;

2) The leachate after passing through the grid net is collected into the adjustment tank, and the sediment is removed by precipitation;

3) transporting the precipitated leachate in the regulating tank to the anaerobic tank for anaerobic reaction to obtain the effluent and sludge of the anaerobic tank, and the sludge is transported to the sludge thickening tank;

4) The effluent part of the anaerobic tank is mixed with the effluent of the regulating tank before entering the anaerobic tank, and the rest of the effluent is transported to the denitrification tank for anoxic reaction;

5) The leachate treated by the denitrification tank is transported to the nitrification tank to carry out aerobic reaction;

6) The leachate treated in the nitrification tank is transported to the ultrafiltration membrane tank, and treated with the ultrafiltration membrane in the ultrafiltration membrane tank to obtain the ultrafiltration effluent and the sludge mixture, and the sludge mixture is partially returned to the reaction chamber. In the nitrification tank, the rest are sent to the sludge thickening tank;

7) After adding flocculant to the pipeline mixer, the ultrafiltration effluent is transported to the flocculation tank, the effluent of the flocculation tank is transported to the ozone oxidation tower for ozone treatment, and the sedimentation of the flocculation tank is transported to the sludge concentration tank. After passing through the filter tank, the effluent can be sent to the clean water tank or discharged outside;

All the sludge transported to the sludge thickening tank 14 is transported into the conditioning box 12 of the screw dehydrator, and flocculant (cationic PAM) is added to make the sludge flocculate into clusters to improve the dehydration efficiency, and the sludge cake and filtrate are obtained after dehydration, The obtained filtrate is transported to the adjustment tank again; the mud cake is transported to landfill.

In the present embodiment, the effluent of the regulating tank is transported to the lower end of the anaerobic tank by the anaerobic feed pump, passes through the packing area in the middle of the anaerobic tank 3 through the upward flow through the water distribution device 10, and passes through the outlet at the upper end of the anaerobic tank 3. Outflow, the height of the packing area is 2-4m.

Specifically, the sewage enters water from the lower part of the anaerobic tank, and the upper part discharges water, and the formed biogas is discharged from the gas guide device in the upper part of the anaerobic tank for collection. There is no need to set a three-phase separator. The anaerobic tank is poor in order from bottom to top. Sludge area, suspension area, packing area and clarification area, because there is a certain space directly between the water distribution device and the filler at the bottom of the pool, it is convenient for the suspended flocculent sludge and granular sludge to grow and accumulate in them. When passing through the suspended sludge layer and the filler layer in sequence, the organic matter will come into contact with the microorganisms on the sludge and the biofilm and be stabilized. In addition to the filler, the UBF anaerobic tank also has a water distribution device and a biogas collection system. The function of the water distribution device is to evenly distribute the influent water in the whole tank, and at the same time, the blockage of the water distribution device should be overcome. The upper closed volume is used to collect biogas, and the biogas collection system includes water seals, gas flow meters, etc.

In order to improve the film-forming ability of the filler area, in this embodiment, the filler includes the following components in parts by weight: 30-40 parts of corncob, 10-20 parts of fly ash, and 60-90 parts of polypropylene hollow microspheres 30 to 45 parts of hydroformylation vinylon silk, and the hydroformylation vinylon silk is placed in the polypropylene hollow microsphere.

In this example, the mixed filler formed according to the above proportioning ratio can complete the film formation within 60-150 hours. At the same time, the corncob can stably release the carbon source while serving as the filler carrier. Its surface structure is rough and porous, and it can also be It is convenient for the attachment of microorganisms in the anaerobic tank, and has a wide range of sources and low cost. Fly ash also has a porous structure, which is easy for microorganisms to attach and grow. The overall treatment effect is good; and the filler without corncob and fly ash has a long film hanging period, low bioaffinity, long film hanging time and easy to fall off. For more than 240h, the COD removal rate of the anaerobic tank is only about 80%, and the suspended sludge in the water is also more than that with corncob and fly ash added, which makes the effluent quality low and the mud content high, which increases the amount of sludge. The load performance of the subsequent treatment device; and the COD removal rate of the improved anaerobic tank can be increased from 80% to more than 93%, effectively improving its treatment efficiency.

The embodiments of the present invention are presented for purposes of illustration and description, and are not intended to be exhaustive or to limit the invention to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to better explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use.

Claims (10)

1. The utility model provides a landfill leachate's processing system which characterized in that: the device comprises a grating pool, an adjusting pool, an anaerobic pool, a denitrification pool, a nitrification pool and an ultrafiltration membrane pool which are sequentially communicated, wherein an ultrafiltration membrane is arranged in the ultrafiltration membrane pool, the liquid outlet end of the ultrafiltration membrane pool is communicated with an ultrafiltration clear water tank, the liquid outlet end of the ultrafiltration clear water tank is connected to a deep treatment device, a sludge outlet of the anaerobic pool, a sludge outlet of the ultrafiltration membrane pool and a sludge outlet of the deep treatment device are all connected to a sludge concentration tank, aeration devices are arranged in the nitrification pool and the ultrafiltration membrane pool, a liquid backflow pipeline is arranged between the liquid outlet end of the anaerobic pool and the adjusting pool, a sludge backflow pipeline is arranged between the sludge outlet end of the ultrafiltration membrane pool and the denitrification pool, a backwashing pipeline is further connected between the ultrafiltration clear water tank and the ultrafiltration membrane pool, the anaerobic pool is cylindrical, and the denitrification pool and the nitrification pool are distributed around the outer side wall of the anaerobic pool, and enclosing the anaerobic tank at the center, wherein the anaerobic tank, the denitrification tank and the nitrification tank are all steel structures.

2. The landfill leachate treatment system of claim 1, wherein: the advanced treatment unit includes pipeline mixer, flocculation and precipitation pond, middle water pitcher, ozone oxidation tower, filter tank and the clear water pitcher that communicates in proper order, the clear water pitcher of ultrafiltration go out the liquid end with pipeline mixer's feed liquor end intercommunication, it has the flocculating agent to add among the pipeline mixer, ozone oxidation tower is connected with ozone generator, sludge discharge mouth and sludge thickening jar intercommunication are passed through to the bottom in flocculation and precipitation pond.

3. The landfill leachate treatment system of claim 2, wherein: the number of the pipeline mixers is two, and the pipeline mixers are connected in series; the flocculation sedimentation tank is a central vertical flow sedimentation tank with an inclined pipe in the middle.

4. The landfill leachate treatment system of claim 1, wherein: the volume ratio of the denitrification tank to the anaerobic tank to the nitrification tank is 1: 1.9-2.3: 1.5-1.7.

5. The landfill leachate treatment system of claim 1, wherein: the ultrafiltration membrane is cylindrical, a mounting plate, a driving motor and a backwashing assembly are also arranged in the ultrafiltration membrane tank, the bottom of the ultrafiltration membrane is open, and is hermetically and detachably arranged on the mounting plate, the backwashing component comprises a transmission shaft, a backwashing transverse branch pipe, a backwashing longitudinal branch pipe, a rotary joint and a high-pressure nozzle, the transmission shaft is positioned in the center of the ultrafiltration membrane, the bottom of the transmission shaft penetrates through the mounting plate to be in transmission connection with the driving motor, the backwash transverse branch pipe is positioned in the ultrafiltration membrane and is connected to the transmission shaft at intervals, the backwash transverse branch pipe at the uppermost end is communicated with the backwash pipeline through the rotary joint, the backwash transverse branch pipe close to one end of the inner wall of the ultrafiltration membrane is communicated with the backwash longitudinal branch pipe, and a plurality of high-pressure nozzles are arranged on the backwash longitudinal branch pipe in an array mode.

6. The landfill leachate treatment system of claim 5, wherein: the back flush subassembly still includes brush yoke axle and cleaning brush, and is a plurality of the one end of brush yoke axle is connected on the circumference lateral wall of transmission shaft, the other end is connected jointly the cleaning brush, the cleaning brush with the inner wall butt of milipore filter.

7. The landfill leachate treatment system of claim 6, wherein: the brush yoke axle includes first connecting axle and second connecting axle, first connecting axle with the transmission shaft is connected, the one end activity cover of second connecting axle is established on the first connecting axle, the other end with the cleaning brush is connected, it is equipped with the spring still to overlap on the first connecting axle, the both ends of spring are connected respectively the transmission shaft with the second connecting axle.

8. A treatment process of landfill leachate is characterized by comprising the following steps: the method comprises the following steps:

1) the garbage percolate passes through a grid net to remove floating objects and suspended matters in the percolate;

2) collecting the percolate passing through the grid net into an adjusting tank, and removing silt through precipitation;

3) conveying the percolate precipitated in the regulating tank to an anaerobic tank for anaerobic reaction to obtain effluent and sludge of the anaerobic tank, and conveying the sludge to a sludge concentration tank;

4) part of the effluent of the anaerobic tank flows back to be mixed with the effluent of the regulating tank and then enters the anaerobic tank, and the rest effluent is conveyed to the denitrification tank for anoxic reaction;

5) conveying the percolate treated by the denitrification tank into a nitrification tank for aerobic reaction;

6) conveying the percolate treated by the nitrification tank into an ultrafiltration membrane tank, treating the percolate by an ultrafiltration membrane in the ultrafiltration membrane tank to obtain ultrafiltration effluent and sludge mixed liquid, refluxing part of the sludge mixed liquid into a denitrification tank, and conveying the rest of the sludge mixed liquid into a sludge concentration tank;

7) adding a flocculating agent into the ultrafiltration effluent in a pipeline mixer for mixing, and then conveying the mixture to a flocculation tank, conveying the effluent of the flocculation tank to an ozone oxidation tower for ozone treatment, conveying the sediment of the flocculation tank to a sludge concentration tank, and conveying the ozone-treated effluent to a clean water tank or discharging the ozone-treated effluent after passing through a filter tank;

and conveying all the sludge conveyed to the sludge concentration tank to a regulating box of a spiral-stacked dewatering machine, adding a flocculating agent, dewatering to obtain a mud cake and filtrate, and conveying the obtained filtrate to a regulating tank again.

9. The landfill leachate treatment process according to claim 8, wherein: the effluent of the adjusting tank is conveyed to the lower end of the anaerobic tank through an anaerobic water inlet pump, passes through a filler area in the middle of the anaerobic tank in an up-flow mode through a water distribution device, and flows out through an outlet in the upper end of the anaerobic tank, and the height of the filler area is 2-4 m.

10. The landfill leachate treatment process according to claim 9, wherein: the filler comprises the following components in parts by weight: 30-40 parts of corncobs, 10-20 parts of fly ash, 60-90 parts of polypropylene hollow microspheres and 30-45 parts of hydroformylation vinylon filaments, wherein the hydroformylation vinylon filaments are placed in the polypropylene hollow microspheres.

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