CN214528544U

CN214528544U - System for treating high ammonia nitrogen in landfill leachate evaporation effluent

Info

Publication number: CN214528544U
Application number: CN202023080178.1U
Authority: CN
Inventors: 杨微; 孙彤辉; 刘洋; 李庆林
Original assignee: Dalian Gty Thermo Tech Co ltd
Current assignee: Dalian Gty Thermo Tech Co ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2021-10-29
Anticipated expiration: 2030-12-21

Abstract

The utility model provides a system for treating high ammonia nitrogen in landfill leachate evaporation effluent, including raw water tank, raw water elevator pump, lye tank, alkali liquor dosing pump, tube mixer, PH value detector, gaseous state membrane device, absorption liquid tank, absorption liquid circulating pump, play water tank, the raw water tank export is through raw water elevator pump and tube mixer entry intercommunication, the alkali liquor tank export is through alkali liquor dosing pump and tube mixer entry intercommunication, the tube mixer export is through the raw water entry intercommunication on gaseous state membrane device upper portion; the absorption liquid tank is communicated with an absorption liquid inlet at the bottom of the gaseous film device through an absorption liquid circulating pump, an absorption liquid outlet at the top of the gaseous film device is communicated with the upper part of the absorption liquid tank, and a water outlet at the lower part of the gaseous film device is communicated with the upper part of the water outlet tank; the utility model discloses the system for disposing landfill leachate evaporation effluent high ammonia nitrogen is with low costs, difficult jam, and process stability is good.

Description

System for treating high ammonia nitrogen in landfill leachate evaporation effluent

Technical Field

The utility model relates to a landfill leachate evaporation effluent treatment technology especially relates to a system for treating high ammonia nitrogen in landfill leachate evaporation effluent.

Background

The landfill leachate refers to sewage formed by leaching water generated by decomposition of organic substances in the garbage and free water, precipitation, infiltrated underground water and the like in the garbage in the landfill and stacking process, and when the humidity of a garbage stack body exceeds the water holding capacity of the garbage stack body, inorganic pollutants such as suspended or dissolved organic pollutants and heavy metals in the garbage stack body are dissolved out together, so that the leachate is generated.

With the gradual improvement of economic level and quality of life of people, the country attaches more importance to the environmental protection career, and new sewage discharge standard is continuously provided, so that the current environmental protection technology industry faces unprecedented opportunities and challenges. In recent years, GB16889-1997 and GB16889-2008 'control standard for pollutants for domestic refuse landfill' are established in succession in China, and the treatment of landfill leachate is increasingly strict.

The MVR treatment process technology has the advantages of small occupied area, high equipment automation degree, simple process flow, stable and reliable operation, strong shock resistance, short construction period, basically no influence of external environment in the operation process, no generation of concentrated solution and the like in the aspect of landfill leachate treatment, and occupies larger and larger market share in the aspect of landfill leachate treatment.

However, when the landfill leachate is treated by MVR evaporation, ammonia nitrogen in the landfill leachate enters steam and finally exists in condensed water, so that the ammonia nitrogen value of effluent is high, and the operation of engineering projects cannot be influenced by discharge. The existing matched process for removing ammonia nitrogen by MVR evaporation is a sulfuric acid scrubbing system, ammonia nitrogen-containing steam evaporated by MVR is introduced into a sulfuric acid scrubbing tower, and ammonia nitrogen in the steam is converted into ammonium sulfate salt by using sulfuric acid solution to remove the ammonia nitrogen.

Such a sulfuric acid scrubbing system has the following major problems:

1. the temperature of the ammonia nitrogen-containing steam evaporated by MVR is 100-; meanwhile, the sulfuric acid gas washing tower adopts 5-10% sulfuric acid solution for gas washing, and the sulfuric acid gas washing tower is required to resist corrosion; the requirements result in high requirements on the material of the sulfuric acid scrubbing tower, and the equipment cost is high.

2. The equipment is easy to block, the concentration of ammonium sulfate in the sulfuric acid gas washing tower is gradually increased to supersaturation, and the blockage of the sulfuric acid gas washing tower and the matched equipment is easy to cause.

3. The process stability is poor, the ammonia nitrogen removal effect is poor due to the blockage of a sulfuric acid scrubbing tower or the low concentration of sulfuric acid in the scrubbing tower, and the evaporation condensate water does not reach the standard.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problems of high equipment cost, easy blockage and poor process stability of the existing sulfuric acid scrubbing system for treating high ammonia nitrogen evaporated from landfill leachate, and provides a method for treating high ammonia nitrogen in landfill leachate evaporated water, wherein the method has low equipment cost, difficult blockage and good process stability.

In order to achieve the above object, the utility model adopts the following technical scheme: a system for treating high ammonia nitrogen in landfill leachate evaporation effluent comprises a raw water tank, a raw water lift pump, an alkali liquor tank, an alkali liquor dosing pump, a pipeline mixer, a PH value detector, a gaseous film device, an absorption liquor tank, an absorption liquor circulating pump and an effluent tank, wherein the raw water tank is used for containing the evaporation effluent of the high ammonia nitrogen, the alkali liquor tank is used for containing a NaOH solution, the absorption liquor tank is used for containing a sulfuric acid, nitric acid or hydrochloric acid solution, and the effluent tank is used for containing effluent after the ammonia nitrogen is removed; the outlet of the raw water tank is communicated with the inlet of the pipeline mixer through a raw water lift pump, the outlet of the alkali liquor tank is communicated with the inlet of the pipeline mixer through an alkali liquor dosing pump, and the outlet of the pipeline mixer is communicated with the raw water inlet at the upper part of the gaseous membrane device; the absorption liquid tank is communicated with an absorption liquid inlet at the bottom of the gaseous film device through an absorption liquid circulating pump, an absorption liquid outlet at the top of the gaseous film device is communicated with the upper part of the absorption liquid tank, and a water outlet at the lower part of the gaseous film device is communicated with the upper part of the water outlet tank;

be provided with the PH value detector on the pipeline between pipeline mixer and the gaseous state membrane device raw water entry, PH value detector, the electrical connection in order of control unit and alkali lye dosing pump, PH value detector feedback signal of telecommunication passes through the control unit, and the rotational speed of automatic control alkali lye dosing pump, the volume of throwing of automatically regulated alkali lye adds.

Furthermore, the membrane selected by the gaseous membrane separation device is a hydrophobic hollow fiber microporous membrane, the thickness of the microporous membrane is 30-100 microns, and the membrane material is polypropylene or polytetrafluoroethylene.

The method for treating high ammonia nitrogen in the landfill leachate evaporation effluent by adopting the system comprises the following steps: add alkali regulation pH value to basicity in evaporating the waste leachate MVR effluent, evaporate the ammonia nitrogen of aquatic with the waste leachate MVR and change into free state ammonia, get into gaseous state membrane separator's waste water side, the absorption liquid gets into gaseous state membrane separator's absorption side simultaneously, free state ammonia in the waste water side gets into the absorption side through gaseous state membrane separator's hydrophobic microporous membrane and takes place quick irreversible reaction with the absorption liquid, thereby reach the purpose of high ammonia nitrogen desorption, final effluent is up to standard and is discharged.

Further, the ammonia nitrogen value in the water evaporated by the landfill leachate MVR is 200-2000 mg/L.

Further, the alkali is NaOH_，The mass concentration of the alkali solution is 30-50 wt%.

Further, adding alkali into the evaporated water of the landfill leachate MVR to adjust the pH value to be alkaline, and adjusting the pH value to 11-13, preferably 12.

Further, the absorption liquid is sulfuric acid, nitric acid or hydrochloric acid, and the acid concentration is 3-5% wt.

Further, the operation pressure of the gaseous membrane separation system is 0-0.25MPa, and the operation temperature is 5-45 ℃. The preferred operating pressure is 0.1-0.15MPa and the operating temperature is 20-30 ℃.

Furthermore, after the landfill leachate MVR treated by the treatment method evaporates the effluent, the removal rate of ammonia nitrogen is more than 98%.

The utility model discloses system for handle high ammonia nitrogen in landfill leachate evaporation effluent specifically is a system for handle high ammonia nitrogen in landfill leachate MVR evaporation effluent based on gaseous state membrane separation technique, compares with prior art and has following advantage:

1) the equipment cost is low, the operating pressure of the gaseous membrane separation system is 0-0.25MPa, the operating temperature is 5-45 ℃, and the equipment is low-pressure low-temperature equipment and has low equipment cost and low energy consumption.

2) The equipment is not easy to block, the cross flow filtration technology adopted by the gaseous membrane separation device continuously washes the surface of the gaseous membrane by water inflow, and the accumulation and the blocking of precipitated salt are avoided.

3) The process stability is good, the process flow of the gaseous membrane separation system is simple, the blockage is not easy, the full-automatic control can be realized, and the effluent stably reaches the standard.

To sum up, the utility model discloses thoroughly solved sulphuric acid scrubbing system and had required very high to equipment, equipment cost is high, and equipment easily blocks up, the poor problem of process stability.

Drawings

FIG. 1 is a schematic view of a system for treating high ammonia nitrogen in landfill leachate evaporation effluent.

Detailed Description

The invention is further illustrated below with reference to the following examples:

example 1

The embodiment discloses a system for treating high ammonia nitrogen in landfill leachate MVR evaporation effluent based on a gaseous membrane separation technology, the structure of which is shown in figure 1, and the system comprises a raw water tank 1, a raw water lift pump 2, an alkali liquor tank 3, an alkali liquor dosing pump 4, a pipeline mixer 5, a pH value detector 6, a gaseous membrane device 7, an absorption liquor tank 8, an absorption liquor circulating pump 9 and an effluent tank 10.

The outlets of the raw water tank 1 and the lye tank 3 are respectively communicated with a pipeline mixer 5, and the outlet of the pipeline mixer 5 is communicated with the raw water inlet at the upper part of the gaseous membrane device 7. Wherein, the raw water tank 1 is filled with high ammonia nitrogen evaporation effluent, and the outlet of the raw water tank 1 is communicated with the inlet of the pipeline mixer 5 through the raw water lift pump 2. An alkali liquor tank 3 is internally provided with an alkali liquor which is NaOH, and the outlet of the alkali liquor tank 3 is communicated with a pipeline mixer 5 through an alkali liquor dosing pump 4; set up PH value detector 6 between pipeline mixer 5 and the raw water entry on gaseous state membrane device 7 upper portion, PH value detector 6, the control unit and alkali lye dosing pump 4 electricity in order link, the signal of telecommunication is passed through to PH value detector 6 feedback, and the rotational speed of automatic control alkali lye dosing pump 4, the volume of throwing of automatically regulated alkali lye is added.

The absorption liquid tank 8 is used for containing sulfuric acid, nitric acid or hydrochloric acid; the absorption liquid tank 8 is communicated with an absorption liquid inlet at the bottom of the gaseous film device 7 through an absorption liquid circulating pump 9, an absorption liquid outlet at the top of the gaseous film device 7 is communicated with the upper part of the absorption liquid tank 8, and a water outlet at the lower part of the gaseous film device 7 is communicated with the upper part of the water outlet tank 10;

by adopting the system, the method for treating high ammonia nitrogen in the evaporated effluent of the landfill leachate MVR based on the gaseous membrane separation technology comprises the following steps:

the method comprises the steps of respectively feeding landfill leachate MVR evaporated water with an ammonia nitrogen value of 1016mg/L in a raw water tank 1 and a sodium hydroxide solution with a mass concentration of 50% in an alkali liquor tank 3 into a pipeline mixer 5, uniformly mixing the water and the sodium hydroxide solution through the pipeline mixer 5, and then feeding the mixed water into a raw water side of a gaseous film device 7, wherein a pH value detector 6 is arranged between the pipeline mixer 5 and a raw water inlet of the gaseous film device 7, an electric signal is fed back to a control unit by the pH value detector 6, the control unit automatically controls the rotating speed of an alkali liquor dosing pump 4, automatically adjusts the dosage of alkali liquor until the pH value of the evaporated water entering the gaseous film device 7 is 12, and ammonia nitrogen in the water evaporated by the landfill leachate MVR is converted into free ammonia; meanwhile, 5% dilute sulfuric acid in the absorption liquid tank 8 enters the absorption side of the gaseous membrane device 7 through the absorption liquid circulating pump 9, free ammonia in the raw water side enters the absorption side to react with the dilute sulfuric acid rapidly and irreversibly, wherein the operation pressure of the gaseous membrane separation system is 0.15MPa, and the operation temperature is 25 ℃. The content of ammonia nitrogen in the final effluent of the gaseous membrane system is 8mg/L, and the removal rate of the ammonia nitrogen is 99.2%.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. A system for treating high ammonia nitrogen in evaporation effluent of landfill leachate is characterized by comprising a raw water tank, a raw water lift pump, an alkali liquor tank, an alkali liquor dosing pump, a pipeline mixer, a PH value detector, a gaseous membrane device, an absorption liquor tank, an absorption liquor circulating pump and a water outlet tank, wherein an outlet of the raw water tank is communicated with an inlet of the pipeline mixer through the raw water lift pump, an outlet of the alkali liquor tank is communicated with an inlet of the pipeline mixer through the alkali liquor dosing pump, and an outlet of the pipeline mixer is communicated with a raw water inlet at the upper part of the gaseous membrane device; the absorption liquid tank is communicated with an absorption liquid inlet at the bottom of the gaseous film device through an absorption liquid circulating pump, an absorption liquid outlet at the top of the gaseous film device is communicated with the upper part of the absorption liquid tank, and a water outlet at the lower part of the gaseous film device is communicated with the upper part of the water outlet tank;

and a PH value detector is arranged on a pipeline between the pipeline mixer and the raw water inlet of the gaseous film device, and the PH value detector, the control unit and the alkali liquor dosing pump are sequentially and electrically connected.

2. The system for treating high ammonia nitrogen in evaporative effluent of landfill leachate according to claim 1, wherein the membrane selected by the gaseous membrane device is a hydrophobic hollow fiber microporous membrane, the thickness of the microporous membrane is 30-100 microns, and the membrane material is polypropylene or polytetrafluoroethylene.