CN211311249U - Landfill leachate treatment system - Google Patents

Abstract

The utility model relates to a landfill leachate processing system, including grid, equalizing basin and the biochemical treatment unit that connects gradually, MBR pond is connected to the delivery port of biochemical treatment unit, goes out the mud mouth and connects the sludge thickening tank, the MBR pond is through the pipe connection RO reverse osmosis unit, and this RO reverse osmosis unit connects the low temperature evaporation unit. Compared with the prior art, the utility model discloses effectively combined the advantage of materialization, biochemical method, membrane treatment, reverse osmosis process, low temperature evaporation, reaction rate is high, and the treatment effect is good, and the working costs is low, and landfill leachate finally can reach the retrieval and utilization water standard, has realized the waste water zero release.

Description

Landfill leachate treatment system

Technical Field

The utility model belongs to the technical field of the waste water treatment technique and specifically relates to a landfill leachate treatment system is related to.

Background

The landfill leachate is high-concentration organic wastewater which is formed by deducting the saturated water holding capacity of garbage and a soil covering layer from water contained in the garbage in a garbage landfill, rain, snow and water entering the landfill and other water and passing through the garbage layer and the soil covering layer. Is high-concentration organic wastewater with complex components, and can cause serious environmental pollution if the high-concentration organic wastewater is directly discharged into the environment without treatment. For the purpose of protecting the environment, it is essential to treat the leachate.

The landfill leachate has the characteristics of high BOD5 and COD concentration, higher metal content, large water quality and water quantity change, higher ammonia nitrogen content, imbalance proportion of microorganism nutrient elements and the like which are different from common urban sewage.

The treatment method of the landfill leachate comprises a physical chemical method and a biological method. The physical and chemical methods mainly comprise various methods such as activated carbon adsorption, chemical precipitation, density separation, chemical oxidation, chemical reduction, ion exchange, membrane dialysis, gas stripping, wet oxidation and the like, and the biological methods are divided into aerobic biological treatment, anaerobic biological treatment and combination of the aerobic biological treatment and the anaerobic biological treatment. The aerobic treatment comprises an activated sludge process, an aeration oxidation tank, an aerobic stabilization pond, a biological rotating disk, a trickling filter and the like. The anaerobic treatment comprises an upflow sludge bed, an anaerobic immobilized bioreactor, a mixing reactor and an anaerobic stabilization pond.

Because the proportion of the macromolecular compounds which are difficult to degrade in the percolate is high, and the inhibition effect of the generation of the existing heavy metals, how to treat the landfill leachate becomes a technical problem to be solved urgently at present.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a landfill leachate treatment system in order to overcome the defect that above-mentioned prior art exists, solved among the prior art landfill leachate and handled the technical problem that is difficult to up to standard.

The purpose of the utility model can be realized through the following technical scheme:

a landfill leachate treatment system, comprising:

a grid, an adjusting tank and a biochemical treatment unit which are connected in sequence,

the water outlet of the biochemical treatment unit is connected with an MBR tank, the sludge outlet is connected with a sludge concentration tank,

the MBR tank is connected with an RO reverse osmosis unit through a pipeline, and the RO reverse osmosis unit is connected with a low-temperature evaporation unit.

The grating is an artificial grating or a mechanical grating, and the gaps between the grating strips are 2-5 mm.

And a water pump is arranged on a pipeline between the regulating tank and the biochemical treatment unit.

The biochemical treatment unit adopts an AO treatment process, water flow sequentially passes through an anoxic zone and an aerobic zone, hydrolysis is carried out in the anoxic zone, and aeration treatment is carried out in the aerobic zone, so that the concentration of ammonia nitrogen and total nitrogen is reduced.

The MBR tank is internally provided with an MBR membrane, the number of membrane modules is set according to the water quantity by adopting a hollow fiber membrane (curtain type membrane), and ammonia nitrogen and total nitrogen in water are removed by continuously operating with an AO process.

The RO reverse osmosis unit is internally provided with an RO reverse osmosis membrane with the aperture of 1/10000 mu m and adopts a hollow fiber membrane.

And a concentrated water pump is arranged on a connecting pipeline between the RO reverse osmosis unit and the low-temperature evaporation unit.

The low-temperature evaporation unit consists of an evaporation tower body, a heat exchanger, a delivery pump and a cooling system, adopts an integrated design, and realizes water evaporation by using the difference of saturated vapor pressure of water molecules in air at different temperatures as mass transfer power.

The low-temperature evaporation unit is externally connected with a heat pump.

Compared with the prior art, the utility model discloses a technical scheme has effectively combined materialization, biochemical method, membrane treatment, reverse osmosis process, low temperature evaporation's advantage, and reaction rate is high, and the treatment effect is good, and the working costs is low, and landfill leachate finally can reach the retrieval and utilization water standard, has realized the waste water zero release.

Drawings

Fig. 1 is a schematic structural diagram of the present invention in the embodiment;

fig. 2 is a process flow diagram for treating landfill leachate.

In the figure, 1-grating, 2-adjusting tank, 3-biochemical treatment unit, 4-MBR tank, 5-RO unit, 6-low temperature evaporation unit, 7-heat pump, 8-sludge concentration tank.

Detailed Description

The present invention will be described in detail with reference to the following embodiments. The following examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that various changes and modifications can be made by one skilled in the art without departing from the spirit of the invention. These all belong to the protection scope of the present invention.

Examples

A landfill leachate treatment system, the structure of which is shown in figure 1, comprises: grid 1, equalizing basin 2 and biochemical treatment unit 3, grid 1 sets up in equalizing basin 2, and the waste liquid of rubbish infiltration intercepts the suspended solid through grid 1, then gets into equalizing basin 2 and adjusts quality of water yield, and the grid that uses is artifical grid or mechanical grid, and the clearance between the grid is 2-5 mm. The water outlet of the biochemical treatment unit 3 is connected with an MBR tank 4, the sludge outlet is connected with a sludge concentration tank 8, the MBR tank 4 is connected with an RO reverse osmosis unit 5 through a pipeline, and the RO reverse osmosis unit 5 is connected with a low-temperature evaporation unit 6.

Be provided with the water pump on the pipeline between equalizing basin 2 and the biochemical treatment unit 3, waste water in the pond promotes through the water pump and gets into biochemical treatment unit 3, through microbiological action and big proportion inner loop technique, further get rid of COD in the waste water, ammonia nitrogen, total nitrogen etc., biochemical treatment unit 3 who uses adopts the AO technology, divide into anoxic zone, aerobic zone, set up the micropore aerator in the aerobic zone, rivers pass through anoxic zone, aerobic zone in proper order, hydrolyze at the oxygen deficiency, carry out aeration treatment in aerobic zone, reduce the concentration of ammonia nitrogen and total nitrogen, it gets into next flow to go out the water.

Be equipped with the MBR membrane in MBR pond 4, adopt hollow fiber membrane (curtain formula membrane), set up the quantity of membrane module according to the water yield, through with AO technology continuous operation, get rid of the ammonia nitrogen and total nitrogen in aquatic, further get rid of organic pollutant and suspended solid through the MBR membrane. The RO reverse osmosis membrane is arranged in the RO reverse osmosis unit 5, the aperture is 1/10000 μm, and a hollow fiber membrane is adopted. The pressure difference is used as driving force to separate pollutants in water, the produced water reaching the standard can be recycled, and the concentrated water enters the next process.

A concentrated water pump is arranged on a connecting pipeline between the RO reverse osmosis unit 5 and the low-temperature evaporation unit 6. The concentrated water is lifted by a concentrated water pump to enter a low-temperature evaporation unit, organic matters, salt, oil and refractory substances in the wastewater are removed, and the condensed water is discharged into the next process. The low-temperature evaporation unit 6 is used, comprises an evaporation tower, a heat exchanger, a delivery pump and a cooling system, and is integrally and intensively arranged. The low-temperature evaporation unit 6 is a novel evaporation technology which utilizes the difference of saturated vapor pressure of water molecules in air at different temperatures as mass transfer power. The saturated vapor pressure of water vapor increases with increasing temperature. The water vapor content in air is very low at room temperature, but near the boiling point of water (80-90 ℃), the water vapor content in air can approach 50% -75%. The water or light-component organic matters are distributed in different proportions in the air and water at different temperatures, and the water or the organic matters are extracted from the wastewater or the solution, so that the separation of salt water or the purification and recovery of substances are realized, and the low-temperature evaporation unit 6 is externally connected with a heat pump 7.

The process for treating landfill leachate is shown in fig. 2, and comprises the following steps:

(1) waste liquid of garbage percolation is intercepted by the grating 1 and enters the regulating tank 2 to regulate water quality and water quantity;

(2) the wastewater in the process (1) is lifted by A water pump to enter A biochemical treatment unit 3, COD, ammoniA nitrogen, total nitrogen and the like in the wastewater are further removed by microbial action and A large-proportion internal circulation technology, the effluent enters the next process, the biochemical treatment unit 3 adopts an A-O-A process flow to carry out aeration treatment on the biochemical treatment unit 3, and simultaneously adopts the large-proportion internal circulation technology to reduce the concentration of the ammoniA nitrogen and the total nitrogen, improve the carbon-nitrogen ratio, achieve biochemical conditions, and the obtained sludge enters A sludge concentration tank 8 and A sludge dewatering tank 9 and then is transported outside;

(3) the effluent of the flow (2) enters an MBR tank 4, aeration treatment is carried out on the MBR tank 4, organic pollutants and suspended matters are further removed through an MBR membrane, and the effluent enters the next flow;

(4) the effluent of the flow (3) is lifted by a pump and enters an RO reverse osmosis unit 5, the pollutants in the water are separated by taking the pressure difference as the driving force, the effluent can be recycled, and the concentrated water enters the next flow;

(5) the concentrated water in the process (4) is lifted by a concentrated water pump to enter a low-temperature evaporation unit 6, organic matters, salt, oil and refractory substances in the wastewater are removed, the condensed water is discharged into the next process for crystallization, and the discharged water is discharged out of the unit; the low-temperature evaporation unit 6 adopts an integrated design and integrates main equipment, auxiliary equipment and a control system. Connecting steam, condensed water, industrial electricity and water inlet and outlet pipelines. The water recovery rate reaches more than 95 percent, low-pressure steam is adopted as steam, and circulating cooling water with the temperature of 20-35 ℃ is adopted as cooling water.

The low-temperature evaporation unit 6 adopted in the embodiment adopts a new evaporation device, and is a novel evaporation technology which utilizes the difference of saturated vapor pressure of water molecules in air at different temperatures as mass transfer power. The saturated vapor pressure of water vapor increases with increasing temperature. The water vapor content in air is very low at room temperature, but near the boiling point of water (80-90 ℃), the water vapor content in air can approach 50% -75%. The water or the light-component organic matters are distributed in different ratios in air and water at different temperatures, and the water or the organic matters are extracted from the wastewater or the solution, so that the separation of brine or the purification and recovery of the substances are realized. Has the following advantages:

1) because the heat transfer surface is separated from the phase change interface, the scaling at the phase change position of the filler does not affect the heat transfer efficiency of the system. Therefore, the system has extremely high tolerance to the structural influence, and can greatly reduce the medicament cost and the solid waste treatment cost in the pretreatment stage.

2) Because the operation temperature is lower, the phase change interface has no heat transfer requirement, the phase change interface of the separation equipment can adopt cheap materials such as plastics and the like without using expensive alloy materials for manufacturing a reaction kettle in the traditional evaporation technology, and the equipment cost can be greatly reduced.

3) Because the filler does not need to use metal, can adopt corrosion-resistant plastics to improve the corrosion resisting property of system, therefore the equipment does not fear strong corrosivity, strong oxidizing substance in the waste water.

4) The system adopts air as the extraction medium of water vapor, the whole process of evaporation and condensation is carried out under normal pressure, and high-specification sealing materials and structural parts are not needed like the traditional evaporator which carries out evaporation under negative pressure or high pressure, so that the instability of the system is greatly reduced. The high-temperature air energy heat pump absorbs low-temperature heat energy in air, converts the low-temperature heat energy into high-temperature heat energy after being compressed by the compressor, has quite obvious energy-saving effect, can save more than 50 percent of power consumption compared with an electric boiler, and reduces the trouble of frequently replacing an electric heating pipe; compared with the traditional coal boiler and oil-fired boiler, the system has the advantages of no pollution, no emission, safety, no need of routine security inspection every year, no need of professional boiler workers, full-automatic temperature control and great reduction of the operating cost by more than 50%.

In the description herein, references to the description of "one embodiment," "an example," "a specific example," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The embodiments described above are intended to facilitate the understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention according to the disclosure of the present invention.

Claims (9)

1. A landfill leachate treatment system, the system comprising:

a grid, an adjusting tank and a biochemical treatment unit which are connected in sequence,

the water outlet of the biochemical treatment unit is connected with an MBR tank, the sludge outlet is connected with a sludge concentration tank,

the MBR tank is connected with an RO reverse osmosis unit through a pipeline, and the RO reverse osmosis unit is connected with a low-temperature evaporation unit.

2. The landfill leachate treatment system of claim 1, wherein the grating is an artificial grating or a mechanical grating, and the gap between the grating strips is 2-5 mm.

3. The landfill leachate treatment system of claim 1, wherein a water pump is disposed in the pipeline between the conditioning tank and the biochemical treatment unit.

4. The landfill leachate treatment system of claim 1, wherein the biochemical treatment unit employs an AO treatment process, comprising an anoxic zone and an aerobic zone.

5. The landfill leachate treatment system of claim 1, wherein the MBR tank is internally provided with MBR membranes, and hollow fiber membranes are adopted.

6. The landfill leachate treatment system of claim 1, wherein the RO reverse osmosis unit is provided with an RO reverse osmosis membrane with a pore size of 1/10000 μm, and a hollow fiber membrane is adopted.

7. The landfill leachate treatment system of claim 1, wherein a concentrate pump is disposed on the connecting pipeline between the RO reverse osmosis unit and the low temperature evaporation unit.

8. The landfill leachate treatment system of claim 1, wherein the low temperature evaporation unit comprises a tower, a heat exchange unit, a fluid delivery and cooling system, and is of an integrated design.

9. The landfill leachate treatment system of claim 1, wherein the low temperature evaporation unit is externally connected to a heat pump.

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