CN218810945U

CN218810945U - Aged stock landfill leachate treatment system

Info

Publication number: CN218810945U
Application number: CN202221639978.9U
Authority: CN
Inventors: 郭晓静; 黄志亮; 陈秋石; 李北涛; 洪毅; 瞿艳军
Original assignee: Beijing Jingwei Environmental Technology Co ltd
Current assignee: Beijing Jingwei Environmental Technology Co ltd
Priority date: 2022-03-30
Filing date: 2022-06-28
Publication date: 2023-04-07
Anticipated expiration: 2032-06-28
Also published as: CN115259546A

Abstract

The utility model relates to an aging stock landfill leachate treatment system, which comprises a coagulating sedimentation tank, an MBR membrane biological reaction system, a single-stage DTRO system, a two-stage A/O system, a tubular UF system, an NF system, an RO system and an evaporation system; the coagulating sedimentation tank is connected with the MBR membrane biological reaction system and the two-stage A/O system in two ways through a pipeline valve; a single-stage DTRO system is connected behind the MBR membrane biological reaction system; the rear part of the two-stage A/O system is sequentially connected with a tubular UF system, a NF system and an RO system; the water outlets of the single-stage DTRO system and the RO system are mixed and discharged; the water inlet of the evaporation system is connected with the concentrated solution outlets of the NF system, the RO system and the single-stage DTRO system. The utility model has the advantages that: the aged stock garbage leachate treatment system degrades, filters and washes leachate, removes COD, NH3, organic matters and particles in the leachate, and achieves the purpose of zero emission.

Description

Aged stock landfill leachate treatment system

Technical Field

The utility model relates to a landfill leachate handles field, in particular to ageing stock landfill leachate processing system.

Background

As the landfill life of the landfill site increases, the ratio of BOD (biochemical oxygen demand) to COD (chemical oxygen demand) is gradually reduced, and the long-term anaerobic environment of the aged landfill site causes the ammonia nitrogen concentration of the percolate to be extremely high and continuously increases along with the increase of the landfill life. The quality of the leachate is also changed continuously in the aging process, for example, the carbon-nitrogen ratio and biodegradability of the leachate are reduced along with the increase of the aging degree, so that the difficulty of biochemical treatment and common membrane system treatment process is increased for the aging leachate treatment.

The method solves the aging percolate treatment problem, and is an urgent need for realizing reduction and full-scale treatment of landfill stock percolate, avoiding illegal accumulation of landfill percolate, and making up the problems of short plates and the like of the conventional landfill percolate treatment process.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an aging stock landfill leachate processing system solves the above-mentioned problem that exists among the prior art.

The utility model provides an above-mentioned technical problem's technical scheme as follows:

an aging stock garbage leachate treatment system comprises a coagulating sedimentation tank, an MBR (membrane bioreactor) membrane biological reaction system, a single-stage DTRO (flat membrane reverse osmosis) system, a two-stage A/O (nitrification/denitrification) system, a tubular UF (tubular ultrafiltration) system, an NF (nanofiltration) system, an RO (common reverse osmosis) system and an evaporation system; the coagulating sedimentation tank is connected with the MBR membrane biological reaction system and the two-stage A/O system in two ways through a pipeline valve; a single-stage DTRO system is connected behind the MBR membrane biological reaction system; the rear part of the two-stage A/O system is sequentially connected with a tubular UF system, a NF system and an RO system; the water outlets of the single-stage DTRO system and the RO system are mixed and discharged; the water inlet of the evaporation system is connected with the concentrated solution outlets of the NF system, the RO system and the single-stage DTRO system.

The utility model has the advantages that: after the leachate is precipitated by the coagulating sedimentation tank, dividing the leachate into two paths, wherein one path of leachate enters an MBR (membrane bioreactor), the MBR membrane bioreactor degrades, filters and washes the leachate, and then the leachate reaches the discharge standard through the circulating filtration of a single-stage DTRO (draw-down reverse osmosis) system; the other path enters a two-stage A/O system, the two-stage A/O system performs nitrification and denitrification treatment on the percolate, then a tubular UF system performs mud-water separation on the percolate, an NF system performs dehydration on the percolate, and an RO system removes residual COD, NH3 (ammonia nitrogen), organic matters and particles to reach the discharge standard; the concentrated solution in the NF system, the RO system and the single-stage DTRO system is precipitated and evaporated by the evaporation system to realize the separation of salt and liquid of the high-concentration salt-containing wastewater, so that the treated leachate is pollution-free and zero-emission.

On the basis of the technical scheme, the utility model discloses can also do following improvement.

Further, the coagulating sedimentation tank is steel integrated equipment, and comprises a dosing stirring area, an inclined tube sedimentation area, a water outlet weir plate, a central water inlet pipe, a conical sludge discharge hopper and an automatic sludge discharge valve.

Further, the MBR membrane biological reaction system comprises an immersed MBR membrane element filtering unit, a defoaming and dosing unit, an aeration unit, a self-absorption water production unit, a cleaning unit and a backwashing unit.

Further, the two-stage A/O system comprises a first-stage denitrification tank, a first-stage nitrification tank, a second-stage denitrification tank, a second-stage nitrification tank and a buffer tank which are connected in sequence.

Further, the MBR membrane biological reaction system, the two-stage A/O system and the water inlet and the water outlet of the tubular UF system can be mutually switched for standby.

Further, single-stage DTRO system, tubular UF system, NF system and RO system are all integrated membrane equipment.

Further, the single stage DTRO, NF, and RO systems have a cartridge filter accuracy of 10 microns.

Further, the evaporation system adopts a forced circulation acid-base gas washing and mother liquor drying salt extraction process.

Drawings

Fig. 1 is a process flow schematic diagram of the aging stock garbage leachate treatment system of the present invention.

In the drawings, the components represented by the respective reference numerals are listed below:

1. the system comprises a coagulation sedimentation tank, 2, MBR membrane biological reaction system, 3, single-stage DTRO system, 4, two-stage A/O system, 5, tubular UF system, 6, NF system, 7, RO system, 8 and evaporation system.

Detailed Description

The principles and features of the present invention are described below in conjunction with the following drawings, the examples given are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

As shown in fig. 1, an aging-based inventory landfill leachate treatment system according to embodiment 1 of the present invention includes a coagulation sedimentation tank 1, an MBR membrane biological reaction system 2, a single-stage DTRO system 3, a two-stage a/O system 4, a tubular UF system 5, an NF system 6, an RO system 7, and an evaporation system 8; the coagulating sedimentation tank 1 is connected with an MBR membrane biological reaction system 2 and a two-stage A/O system 4 in two ways through a pipeline valve; a single-stage DTRO system 3 is connected behind the MBR membrane biological reaction system 2; the rear part of the two-stage A/O system 4 is sequentially connected with a tubular UF system 5, a NF system 6 and an RO system 7; the water outlets of the single-stage DTRO system 3 and the RO system 7 are mixed and discharged; the water inlet of the evaporation system 8 is connected with the concentrated solution outlet of the NF system 6, the RO system 7 and the single-stage DTRO system 3.

After the leachate is precipitated by the coagulating sedimentation tank 1, dividing the leachate into two paths, wherein one path of leachate enters an MBR (membrane bioreactor) system 2, the MBR membrane bioreactor system 2 degrades, filters and washes the leachate, and then the leachate is circularly filtered by a single-stage DTRO (draw back ro) system 3 to reach the discharge standard; the other path enters a two-stage A/O system 4, the two-stage A/O system 4 performs nitration and denitrification treatment on the percolate, then a tubular UF system 5 performs mud-water separation on the percolate, an NF system 6 performs dehydration on the percolate, and an RO system 7 removes residual COD, NH3, organic matters and particles to reach the discharge standard; the concentrated solution in the NF system 6, the RO system 7 and the single-stage DTRO system 3 is precipitated and evaporated by the evaporation system 8 to realize the separation of salt and liquid of the high-concentration salt-containing wastewater, so that the treated leachate has no pollution and zero emission.

The embodiment 2 of the utility model provides an aging stock landfill leachate processing system, on embodiment 1's basis, coagulating sedimentation tank 1 is steel integration equipment, including adding medicine stirring area, pipe chute settling zone, play water weir plate, central inlet tube, toper mud bucket and automatic mud valve. The coagulating sedimentation tank 1 is steel integrated equipment, integrates auxiliary equipment for automatically adding medicaments, stirring, discharging sludge and the like, and can realize automatic operation. The functional principle is mixing and stirring → flocculation reaction → inclined tube sedimentation → sludge discharge → external transportation of clear water; the coagulating sedimentation tank 1 is round or square in shape, sewage enters the tank from an inlet of a central pipe, is distributed on the whole horizontal section in the circumferential direction through the blocking of a reflecting plate and slowly flows upwards, calcium oxide is added into the coagulating sedimentation tank 1 to adjust the pH value to 12-13, then coagulant and flocculant are added, suspended matters are formed into flocs under the action of the coagulant and the flocculation under the alkaline condition, the flocs are precipitated under the stirring action, precipitated sludge is collected through a conical hopper, sludge is discharged through an automatic sludge discharge valve, clear water floats upwards, passes through an inclined pipe and overflows to a water outlet weir plate, the flow of the clear water flows to a water outlet of the coagulating sedimentation tank 1 and is divided into two paths, one path enters an MBR membrane biological reaction system 2, and the other path enters a two-stage A/O system 4. The removal rate of suspended matters in the coagulating sedimentation tank 1 can reach more than 90 percent.

The embodiment 3 of the utility model provides an aging stock landfill leachate processing system, on embodiment 1's basis, MBR membrane biological reaction system 2 includes submergence formula MBR membrane element filter unit, defoaming and adds medicine unit, aeration unit, produces water unit, cleaning unit and backwash unit from inhaling. Can realize multiple functions of biodegradation, filtration, activated sludge backflow, automatic flushing, online cleaning, offline cleaning and the like. The method has obvious effect on removing the organic matter content and ammonia nitrogen of the leachate, the removal efficiency of pollutants is high, and the removal rate of COD, ammonia nitrogen and the like can reach more than 90 percent.

The embodiment 4 of the utility model provides an aging stock landfill leachate processing system, on embodiment 1's basis, two-stage AO system 4 nitrifies pond, second grade denitrification pond, second grade nitrification pond and buffer pool including the one-level denitrification pond, one-level that connect gradually.

The other path of effluent of the coagulating sedimentation tank 1 enters a two-stage A/O system 4, denitrification is firstly carried out in an anoxic zone of the two-stage A/O system, nitrite and nitrate which flow back from a nitrification section and a rear-end tubular UF system 5 are subjected to denitrification reduction to generate nitrogen, and part of biodegradable organic matters are removed; then the percolate enters a nitrification section, most organic pollutants are degraded in an aerobic zone through aeration, and pass through nitrate

Most of free NH3-N in the wastewater is oxidized into nitrite or nitrate by the action of the bacteria and then flows back to the denitrification section 5; the effluent of the primary nitrification section enters a secondary denitrification section, and a large amount of nitrite and nitrate in the leachate are subjected to denitrification reaction and reduced into nitrogen gas, so that the integral denitrification effect of the system is improved; and (4) allowing the secondary denitrification effluent to enter secondary nitrification so as to further remove organic pollutants and reductive total nitrogen pollutants in water.

The specific reaction process is as follows:

NH4+ → NO3- → NO2- → NO → N2O → N2 (ammonia conversion process)

0NH4+ +2O2 → NO3- +2H + + H2O +346.69kJ (nitration reaction)

5C + H2O 4NO3 → 2N2+4OH +5CO2 (denitrification reaction)

The two-stage A/O system 4 ensures that the percolate stays for at least 12 days in the system, and ensures that more than 99 percent of COD and ammonia nitrogen are effectively degraded in a biochemical stage. The buffer pool in the two-stage A/O system 4 can ensure one

The sludge concentration in the stage biochemical system can also reduce the sludge entering the tubular UF system 5, improve the water yield of the ultrafiltration membrane of the UF5 system 5 and reduce the risk of blockage of the ultrafiltration membrane of the UF system 5.

The embodiment 5 of the utility model provides an aging stock landfill leachate processing system, on embodiment 4's basis, MBR membrane biological reaction system 2 and two-stage AO system 4, tubular UF system 5's water inlet and delivery port can each other be reserve switching. The water quality of the effluent of the biochemical system is ensured to be stable, the COD of the biochemical effluent is less than 1000mg/L and the ammonia nitrogen value is less than 1000mg/L.

0 the embodiment 6 of the utility model provides an aging stock landfill leachate processing system, on embodiment 1's basis, single-stage DTRO system 3, tubular UF system 5, NF system 6 and RO system 7 are integrated a body membrane equipment. The water inlet pump, the security filter, the valve, the instrument and the membrane element are all skid-mounted and integrated with the equipment body, and integrated installation and automatic operation can be realized.

The single-stage DTRO system 3 consists of a core filter, a high-pressure plunger pump, an online circulating pump and a DT membrane group 5. The percolate entering the core type filter directly enters a high-pressure plunger pump and enters a DT membrane component from a water outlet of the high-pressure plunger pump. The DT membrane adopts a butterfly tube type flat plate membrane, has the advantages of strong pollution resistance and strong adaptability to percolate, and the service life of the DT membrane adopting the structure can be prolonged by more than three years. As the flow of the high-pressure plunger pump is not enough to directly supply water to the DT membrane, part of the concentrated solution at the outlet of the DT membrane is refluxed to the inlet of the online circulating pump by the online circulating pump to increase the flow of the DT membrane; improve the water permeation efficiency of the DT membrane component.

The tubular UF system 5 is provided with a precision filter before entering the UF membrane, so that the pollution and blockage caused by the fact that fiber substances enter the UF membrane are prevented, and meanwhile, when sludge is acclimated in the previous period, the sludge is filtered and washed, and impurities in the sludge are reduced; the tubular UF system 5 is an integrated skid-mounted device, namely, all related devices such as a water pump and a membrane shell and an automatic control system are skid-mounted on a device frame, so that automatic and integrated operation is realized; the UF membrane adopts an external tubular ultrafiltration membrane, the effluent of the buffer tank enters the UF membrane for sludge-water separation, the sludge concentration in a two-stage A/O biochemical system can reach 15-20 g/L through the interception function of the UF membrane, the sludge age of the sludge is prolonged, the strains of nitrified autotrophic bacteria can effectively grow in the tank, and meanwhile, microbial flora is formed through continuous domestication, so that organic matters which are difficult to degrade in the leachate can be removed.

The NF system 6 consists of a nanofiltration water inlet pump, a high pressure pump, a security filter, a nanofiltration membrane component, a dosing device and the like, which are all integrated on one set of integrated device. Meanwhile, an online monitoring device, a cleaning device and a control system are integrated, and full-automatic operation, automatic monitoring, fault diagnosis, automatic cleaning and the like of the system are realized. Acid in the NF system 6 is added with medicine to ensure that the nanofiltration membrane operates in an acidic environment to reduce scaling risk, reducing agent is added with medicine to ensure that the nanofiltration membrane is not oxidized, and antisludging agent is added with medicine to ensure that the nanofiltration membrane greatly reduces scaling of the nanofiltration membrane, so that the NF system 6 operates stably for a long time. The nanofiltration membrane component adopts a Dow nanofiltration membrane element, and the desalination rate of the Dow nanofiltration membrane element is superior to that of a standard polyphenylamine roll-type membrane element for inlet water with poor water quality; the Dow nanofiltration membrane element is specially designed for inflow water with relatively high suspended solid content, the Dow nanofiltration membrane element is provided with a glass fiber reinforced plastic shell, and the characteristics of the membrane element are combined, a unique two-section membrane arrangement mode is adopted, so that the permeation pressure is reduced, the permeation of certain salts is reduced, and the water yield of the NF system 6 is greatly improved.

The RO system 7 comprises an RO water inlet pump, a high-pressure pump, a cartridge filter, an RO membrane component, a dosing device and the like, and is integrated on a set of device. Meanwhile, an online monitoring device, a cleaning device and a monitoring system are integrated, so that the full-automatic operation, automatic monitoring, fault diagnosis, automatic cleaning and the like of the system are realized.

And online monitoring instruments such as pH, pressure, flow and conductivity are arranged in the RO system 7, so that the long-term stable operation of the RO system 7 is guaranteed. The RO system 7 adopts a spiral-wound structure of a ceramic (FILTEC) reverse osmosis membrane, and the aperture of the reverse osmosis membrane is generally 0.1 nm-1 nm; not only can effectively remove residual COD, NH3 and the like in water, but also can remove various organic matters and particles in water, and has no pollution, so that the effluent quality is better, and the water yield is higher.

The embodiment of the utility model provides a 7 ageing stock landfill leachate processing system, on embodiment 6's basis, single-stage DTRO system 3, NF system 6 and RO system 7's safety filter precision is 10 microns. Further protect the safety of membrane structure, reduce the scale deposit risk of membrane group, make the system can long-term stable operation.

The embodiment 8 of the utility model provides an aging stock landfill leachate processing system, on embodiment 1's basis, vaporization system 8 adds acid-base gas washing and mother liquor mummification for forced circulation and carries the salt technology. The concentrated solution is modulated into a proper PH range and then enters a stock solution tank, the concentrated solution is conveyed to an exchanger by a water inlet pump to exchange heat with distilled water discharged from a system, and energy of non-condensable gas is recovered by the heat exchanger and then enters an MVR evaporation main body to be evaporated. The evaporated water is changed into steam, the steam enters an acid-base gas washing device after gas-liquid separation, and the gas washing device is pumped out by a steam compressor after ammonia nitrogen and organic matters are removed in an acid washing gas unit and an alkali washing gas unit. The secondary steam is compressed by a steam compressor and heated, then returns to the MVR evaporation unit to heat the material, the steam releases latent heat and then becomes distilled water, and the distilled water is temporarily stored in a distilled water tank and then is conveyed to a heat exchanger through a pump to be discharged out of the system after energy is recovered. The unevaporated liquid is gathered in the MVR bottom, and partly continue circulation evaporation after mixing with the concentrate, and another part is carried to the mummification device by the thick liquids pump and is handled after the rising concentration, and the crystal of separating can be regarded as solid useless and recycled, realizes that the high concentration contains salt waste water salt, liquid separation from this, can reach the purpose of landfill leachate zero release.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. An aging stock landfill leachate treatment system is characterized by comprising a coagulation sedimentation tank (1), an MBR membrane biological reaction system (2), a single-stage DTRO system (3), a two-stage A/O system (4), a tubular UF system (5), an NF system (6), an RO system (7) and an evaporation system (8); the coagulating sedimentation tank (1) is divided into two paths through a pipeline valve and is connected with the MBR membrane biological reaction system (2) and the two-stage A/O system (4); the single-stage DTRO system (3) is connected behind the MBR membrane biological reaction system (2); the pipe type UF system (5), the NF system (6) and the RO system (7) are sequentially connected behind the two-stage A/O system (4); the water outlets of the single-stage DTRO system (3) and the RO system (7) are discharged in a mixed mode; the water inlet of the evaporation system (8) is connected with the concentrated solution outlet of the NF system (6), the RO system (7) and the single-stage DTRO system (3).

2. The aging inventory landfill leachate treatment system of claim 1, wherein the coagulation sedimentation tank (1) is a steel integrated device, comprising a dosing and stirring area, an inclined tube sedimentation area, a water outlet weir plate, a central water inlet pipe, a conical mud discharge hopper and an automatic mud discharge valve.

3. The aging inventory landfill leachate treatment system of claim 1, wherein the MBR membrane biological reaction system (2) comprises an immersed MBR membrane element filtration unit, a defoaming and dosing unit, an aeration unit, a self-priming water production unit, a cleaning unit and a backwashing unit.

4. The aging inventory landfill leachate treatment system of claim 1, wherein the two-stage A/O system (4) comprises a primary denitrification tank, a primary nitrification tank, a secondary denitrification tank, a secondary nitrification tank and a buffer tank connected in sequence.

5. The aging inventory landfill leachate treatment system of claim 4, wherein the MBR membrane biological reaction system (2) and the two-stage A/O system (4), and the water inlet and the water outlet of the tubular UF system (5) are switched for each other.

6. The aging inventory landfill leachate treatment system of claim 1, wherein the single-stage DTRO system (3), the tubular UF system (5), the NF system (6) and the RO system (7) are integrated membrane equipment.

7. The aging inventory landfill leachate treatment system of claim 6, wherein the single stage DTRO system (3), the NF system (6) and the RO system (7) have a cartridge filter accuracy of 10 microns.

8. The aging inventory landfill leachate treatment system of claim 1, wherein the evaporation system (8) employs forced circulation, acid and alkali gas washing and mother liquor drying salt extraction processes.