CN215667444U - Landfill leachate treatment facility - Google Patents

Abstract

The utility model provides a garbage leachate treatment device, which is suitable for treating leachate in a middle and later period garbage landfill, and comprises a basket filter, a coagulating sedimentation tank, a two-stage disc tube type reverse osmosis DTRO (direct digital osmosis) device and an oxidation tank, wherein the coagulating sedimentation tank is used for removing suspended matters and easily precipitated heavy metal suspended matters, pollutants in the leachate are removed through the two-stage DTRO, and the pollutants in the biochemical-unavailable part are forcedly decomposed by the strong oxidizing property of ozone and hydrogen peroxide to further remove the pollutants.

Description

Landfill leachate treatment facility

Technical Field

The utility model relates to a landfill leachate treatment device, which is particularly suitable for treating middle and later-period landfill leachate.

Background

The leachate of the refuse landfill at the middle and later stages mainly contains water contained in the refuse, rain, snow and other water entering the landfill, subtracts the saturated water holding capacity of the refuse and the soil covering layer, and passes through the refuse layer and the soil covering layer to form high-concentration organic wastewater.

Such percolates have the following characteristics:

1. the concentration of organic matters is low (relative to the initial landfill leachate), the content of ammonia nitrogen is high, and the biodegradability is low. Wherein the content of soluble organic substances including hydrocarbons, volatile fatty acids, humic acid, etc. is reduced;

2. the salinity and the conductivity are high, and the salinity and the conductivity are gradually increased along with the recharging of the concentrated solution after the leachate treatment.

3. The metal content is high.

4. The sensory properties were very poor. The compressed liquid is yellow or brown, and has strong acid odor, ammonia odor and turbidity.

5. Through the sampling analysis of a plurality of leachate treatment stations, the water quality is as follows:

CODcr＝5000-10000mg/L

BOD5＝2000-4500mg/L

NH3-N＝1200-1800mg/L

SS＝500-1000mg/L

PH＝6.5-8.5

the water quantity of the percolate is small, and the change range of the concentration of pollutants is large. If not treated, the method can cause serious pollution to local water environment and pose great threat to the health life of surrounding residents. At present, the treatment technology of the landfill leachate comprises a biological method, a physical and chemical method, an artificial wetland, a membrane technology and the combination of various methods, wherein the treatment engineering of the leachate using the DTRO technology, especially two-stage DTRO, has more than 200 seats in the world, and has the advantages of stable operation, good treatment effect, strong adaptability, no need of biochemistry and quicker starting. The ammonia nitrogen content of the water produced by using DTRO is higher, and sometimes the discharge requirements of the country on ammonia nitrogen and total nitrogen cannot be met, so that the defects of the DTRO can be overcome after the pretreatment and the advanced treatment are added.

Disclosure of Invention

In order to make up for the defects of two-stage DTRO treatment of the landfill leachate, the utility model provides a landfill leachate treatment device, which is suitable for treating the landfill leachate at the middle and later stages and is characterized in that: the equipment comprises a basket filter, a coagulating sedimentation tank, a two-stage disc tube type reverse osmosis DTRO device and an oxidation tank which are connected in sequence, the basket filter consists of a connecting pipe, a cylinder body, a filter screen, a flange cover and a fastener, which is arranged on a pipeline at a raw water inlet, the coagulating sedimentation tank is used for removing suspended matters and heavy metal suspended matters which are easy to precipitate, the two-stage DTRO device comprises a first-stage DTRO membrane system and a second-stage DTRO membrane system, the two-stage DTRO device is used for removing pollutants in the percolate, and also comprises a first-stage high-pressure pump and a second-stage high-pressure pump which are respectively connected with the first-stage DTRO membrane system and the second-stage DTRO membrane system, the oxidation pond carries out forced decomposition on the pollutants of the non-biochemical part by utilizing the strong oxidizing property of the ozone and the hydrogen peroxide, the equipment adopts a basket filter, coagulating sedimentation, two-stage DTRO and ozone oxidation and hydrogen peroxide combined treatment process. The treatment process that this equipment adopted not only keeps the advantage of two-stage DTRO technique, can also effectually remove ammonia nitrogen and total nitrogen, guarantees that the effluent is up to standard to discharge.

The technical scheme of the utility model is as follows: the method adopts a basket filter, coagulating sedimentation, two-stage DTRO, ozone oxidation and hydrogen peroxide treatment process, and comprises the following steps:

a regulating pool: the regulating reservoir is used for storing the percolate and is used for regulating the water quality and quantity of inlet water of a percolate treatment plant. Sufficient leachate is stored in the leachate regulating tank, so that the normal operation of subsequent equipment is met, and the leachate is prevented from overflowing and polluting the environment.

A basket filter: the basket filter is mainly installed on a pipeline and can remove large solid impurities in fluid, so that subsequent machine equipment can normally work and operate, the technical process is stabilized, and the safety production is guaranteed.

Coagulating sedimentation: the purpose of coagulation is to make colloidal particles which are difficult to precipitate in water to form precipitates by adding a medicament (PAC, PAM) into water. Mainly removes Suspended Solids (SS) and COD (chemical oxygen demand) of 10-30 percent.

Two-stage DTRO: the percolate passes through the gap between the membrane stack and the shell and then enters the bottom diversion disc through the diversion channel, the treated liquid rapidly flows through the filtering membrane at the shortest distance, and the permeate liquid is continuously discharged through the central collecting pipe while the feed liquid flows through the filtering membrane. And the concentrated solution finally flows out from the flange of the feed end and enters a concentrated solution pool.

Ozone oxidation with hydrogen peroxide (H)₂O₂): the synergistic effect of ozone and hydrogen peroxide can generate hydroxyl free radicals with extremely strong oxidation effect, and organic pollutants in water can be effectively removed. The ozone and hydrogen peroxide process is effective in removing organic pollutants in natural water, and has removal rate on COD and chromaticity and disinfection effect.

The removal rate of COD by the combined process of two-stage DTRO, ozone oxidation and hydrogen peroxide reaches more than 99 percent. The concentrated solution generated by the two-stage DTRO is transported to an incineration plant, and when the local hazardous waste liquid is disposed of, the concentrated solution is transported to the incineration plant for incineration.

Compared with the conventional two-stage DTRO treatment technology, the treatment technology of the utility model has the following advantages:

1. the basket filter is installed in the pipeline of raw water inlet, has held back most large granule suspended solid to ensure raw water and reduce the harm to equipment.

2. The coagulating sedimentation is a process of adding polyaluminium chloride, polyacrylamide and the like in production to enhance the sedimentation effect and adjust the pH value to be proper, so that suspended substances in the wastewater are gathered under the action of a coagulant to further sink under the action of gravity, and the solid-liquid separation is realized. And can effectively reduce the turbidity in the wastewater.

3. The leachate is divided into a concentrated solution (with extremely high pollutant content) and clear water (with a small amount of salt) through a disc tube type reverse osmosis membrane (DTRO), the occupied area is small, the automation degree is high, and the requirement on operation managers is low.

4. The removal rate of COD can reach 70% by the synergistic application of ozone and hydrogen peroxide, and the ozone and hydrogen peroxide have the effects of removing the concentration of other pollutants, disinfecting and the like, and can not generate secondary pollution.

5. The whole processing system has the advantages of short starting time and low energy consumption.

Drawings

Fig. 1 shows a landfill leachate treatment facility provided by the present invention.

Detailed Description

As shown in fig. 1, the garbage leachate basket filter + coagulating sedimentation + two-stage DTRO + ozone oxidation and hydrogen peroxide treatment process of the present invention is performed by the following steps:

(1) because the change of the water quality and the water quantity of the landfill leachate is large, the leachate enters the regulating tank after being subjected to grating removal of large suspended matters, and the regulating tank stores the leachate for regulating the water quality and the water quantity of the inflow water of a leachate treatment plant. The design volume of the percolate adjusting tank is determined according to the local rainfall by considering the maximum accumulated capacity. The designed volume is enough, the percolate does not overflow, and the pollution to the surrounding environment is avoided.

(2) After the water quality and the water quantity are adjusted by the adjusting tank, the percolate is lifted to a coagulating sedimentation tank by a lifting pump, and large-particle suspended matters are removed by a basket filter in the middle. The removal of suspended matters in water reaches 95%, and the filter has a certain removal effect on impurities such as macromolecular organic matters, viruses, bacteria, colloids, iron and the like.

(3) Filtering by a filter, allowing the percolate to enter a coagulation sedimentation tank, adjusting the pH value to 8-9 by using alkali under the automatic control of a pH online controller, adding PAC (with the configuration concentration of 5-10%), stirring, adding PAM anion (with the concentration of 0.1-0.5%), stirring, coagulating for 10min to form an easily-settled floc to obtain a mud-water mixture, allowing the mud-water mixture to enter the sedimentation tank, performing mud-water separation to remove precipitated particle impurities and heavy metal pollutants, separating to obtain a primary supernatant, and discharging the separated sludge and scum into a sludge concentration tank by using a sludge discharge pump for subsequent treatment, wherein the surface hydraulic load of the sedimentation tank is 1m³/m²H, the hydraulic retention time is 5 h.

(4) And (3) the sludge in the coagulating sedimentation tank enters a sludge tank, the supernatant enters two stages of DTRO (double-stage DTRO), and advanced treatment is carried out by using the two stages of DTRO (disc tube type reverse osmosis). And the primary DTRO directly enters the high-pressure plunger pump through the percolate of the core type filter. And a shock absorber is arranged behind each plunger pump of the DT membrane system and is used for absorbing pressure pulses generated by the high-pressure pump and providing stable pressure for the reverse osmosis membrane column. The effluent passing through the high-pressure pump enters an online pump or a membrane column. Because the flow behind the high-pressure pump is not enough to directly supply water, a part of concentrated solution at the outlet of the membrane column flows back to the inlet of the online pump through the online pump so as to ensure the sufficient flow and flow velocity on the surface of the membrane and avoid membrane pollution. The high pressure and high flow rate flowing out from the online pump directly enter the membrane column.

The effluent of the membrane column group is divided into two parts of concentrated solution and permeate, and a pressure regulating valve is arranged at the end of the concentrated solution and used for controlling the pressure in the membrane group so as to generate the necessary purified water recovery rate. The permeate enters a secondary membrane column for further treatment. And discharging the concentrated solution into a concentrated solution storage pool to wait for recharging or outward transportation for disposal.

And in the second-stage DTRO, the permeate after being treated by the first-stage DT membrane system is directly sent to a second-stage DT membrane system high-pressure pump without adding any medicament, a buffer tank is not required to be arranged between the first stage and the second stage, and the flow is automatically matched when the system runs. The second-stage high-pressure pump is provided with variable frequency control, the operation frequency and the output flow of the second-stage high-pressure pump are automatically matched according to the feedback value of the first-stage permeation liquid flow sensor, and meanwhile, the inlet pipeline of the second-stage high-pressure pump is provided with concentrated liquid self-compensation, so that the operation of a second-stage system is not influenced by the water supply quantity of the system. The second-stage reverse osmosis does not need an online booster pump, and the requirement of using a high-pressure pump can be met due to the fact that the feed water conductivity is low and the recovery rate is high.

And a servo motor control valve is arranged at the end of the secondary concentrated solution and used for controlling the pressure and the recovery rate in the membrane group. And (3) leading the concentrated solution in the second-stage membrane to the water inlet end of the first-stage system so as to improve the recovery rate of the system, discharging the permeation solution into a degassing tower, blowing and supporting to remove gases such as carbon dioxide in water so as to enable the pH value to reach 6-9, and leading the solution to enter the next stage.

(5) After two-stage DTRO, most of organic matters, ammonia nitrogen, SS, and the like in the sewage are removed. But any small part of ammonia nitrogen organic matters are not removed, after DTRO goes out of water, the permeate enters ozone and hydrogen peroxide, the ozone and hydrogen peroxide react for 15 minutes under the condition that the PH is 8, the organic matters, ammonia nitrogen and total phosphorus are further removed, the effect is obvious, and the sewage is disinfected. And no secondary pollution is generated. The ozone treated effluent directly enters a clean water tank to be discharged after reaching the standard.

After the garbage percolate basket filter, the coagulating sedimentation, the two-stage DTRO, the ozone oxidation and the hydrogen peroxide treatment process, the effluent quality can reach the control requirement that the designed effluent quality reaches the relevant requirement of table 2 of the national pollution control Standard for municipal solid waste landfill (GB 16889-. The data before and after the landfill leachate is treated by the process are shown in the following table 1.

TABLE 1 data sheet before and after garbage leachate basket filter, coagulating sedimentation, two-stage DTRO and ozone oxidation and hydrogen peroxide treatment

Unit: mg/L pH dimensionless

Item	CODCR	BOD5	NH3-N	SS	PH
						Raw water quality of percolate	5000-10000	2000-4500	1200-1800	500-1000	6.5-8.5
Effluent of the coagulating sedimentation tank	4500-9000	1900-4050	1140-1710	350-700	6-9
						Two-stage DTRO effluent	210-420	22.5-76.5	15.8-36	16-26	6-9
Ozone and hydrogen peroxide effluent	＜100	＜30	＜25	＜30	6-9

Claims (2)

1. The utility model provides a landfill leachate treatment facility, is applicable to the processing of middle and later stage landfill leachate, its characterized in that: the equipment comprises a basket filter, a coagulating sedimentation tank, a two-stage Disc Tubular Reverse Osmosis (DTRO) device and an oxidation pond which are sequentially connected, wherein the basket filter consists of a connecting pipe, a cylinder, a filter screen, a flange cover and a fastener, the coagulating sedimentation tank is arranged in a pipeline of a raw water inlet, the coagulating sedimentation tank is used for removing suspended matters and easily precipitated heavy metal suspended matters, the two-stage Disc Tubular Reverse Osmosis (DTRO) device comprises a one-stage DTRO membrane system and a two-stage DTRO membrane system and is used for removing pollutants in percolate, the two-stage Disc Tubular Reverse Osmosis (DTRO) device further comprises a first-stage high-pressure pump and a second-stage high-pressure pump which are respectively connected with the one-stage DTRO membrane system and the two-stage DTRO membrane system, and the oxidation pond utilizes the strong oxidizing property of ozone and hydrogen peroxide to forcedly decompose part of pollutants which can not be biochemically generated.

2. The landfill leachate treatment plant of claim 1, wherein: and a shock absorber is arranged behind the high-pressure plunger pump of each stage of DTRO membrane system, the pretreated percolate enters the membrane column through the primary high-pressure pump, and the permeate liquid treated by the primary DTRO membrane system directly enters the secondary DT membrane system through the secondary high-pressure pump.

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