KR100882230B1 - Disposal apparatus of livestock wastewater and disposal method thereof - Google Patents

Abstract

An apparatus for treating waste water of livestock is provided to process stably and highly livestock wastewater containing highly concentrated organic, total nitrogen(T-N) and total phosphorous(T-P) and to be used as liquid manure by producing enriched water minimizing the total dissolved solid(TDS) . An apparatus for treating waste water of livestock contains: an ultrafiltration unit including an ultrafiltration membrane filtering the livestock wastewater passing through a pre-anoxic tank(2), an aeration tank(4), a post-anoxic tank(5) and a membrane separation aeration tank(6); and a reverse osmosis unit(7) including a reverse osmosis membrane and a nano membrane for successively filtering the livestock wastewater passing through the ultrafiltration unit.

Description

Livestock wastewater treatment apparatus and its treatment method {Disposal apparatus of livestock wastewater and disposal method

The present invention relates to livestock wastewater treatment, and more particularly to a livestock wastewater treatment apparatus and its treatment method.

The biggest problem among the livestock wastewater is pigs wastewater, and the quality of the generated wastewater depends on various factors such as the type of pigs raised in farming farmers, the type of breeding pigs, the amount of water and water supply facilities, the presence and absence of sewage and urine collection, In general, the water quality of domestic pigs wastewater is SS 10,000 ~ 60,000mg / l, BOD 20,000 ~ 80,000mg / l, TN 2,000 ~ 12,500mg / l, TP 100 ~ 500mg / l. Is also very high.

If these wastewaters are discharged to natural water without proper treatment, the water system loses self-cleaning ability and gradually deteriorates water quality by anaerobicizing the water system with dissolved oxygen (DO) depletion by high organic matter and total nitrogen (T-N). Therefore, there is an urgent need for a method that can more reliably treat livestock wastewater.

In Korea, anaerobic digestion methods such as long-term aeration and liquid corrosion methods and anaerobic digestion methods, such as non-abrasion methods, were introduced in Korea in the early 1990s for the treatment of high concentration livestock wastewater.However, both nitrogen and total phosphorus (TN) and total phosphorus ( TP) could hardly be removed.

Since then, methods have been proposed to treat total nitrogen and phosphorus simultaneously with organic matter. In this process, nitrification and denitrification processes using microorganisms are introduced, and various methods such as precipitation, ozone treatment, membrane separation (UF) and electrooxidation methods using inorganic chemicals are applied as subsequent processes. Due to fluctuations in efficiency, COD _Mn 50 mg / l and TN 60 mg / l are difficult to maintain stably, thus showing limitations in generalization.

Meanwhile, a method using a reverse osmosis membrane has been introduced as a method for reliably treating contaminants that have been a problem such as hardly degradable organic matter and total nitrogen after biological treatment.

These reverse osmosis membranes can be used as a liquid fertilizer by increasing the total dissolved solids (TDS) in concentrated water by filtering most of the inorganic ions in the wastewater with contaminants by reverse osmosis membranes. As it is not suitable, most of them are finally disposed of by dumping at sea.

In addition, the high total dissolved solids concentration increases osmotic pressure (osmosis), which requires a lot of power to concentrate, and as a result, it is difficult to achieve the concentrated magnification more than four times compared to raw water, which results in a large amount of concentrated water, which is expensive to dispose of. It is becoming.

The present invention stably and highly treats livestock wastewater containing high concentrations of organic matter, total nitrogen (TN) and total phosphorus (TP) to produce concentrated water that satisfies the effluent water quality standards of public treatment plants and minimizes total dissolved solids (TDS). It is an object of the present invention to provide a livestock wastewater treatment apparatus and its treatment method which can be used as a liquid fertilizer.

In the livestock wastewater treatment apparatus according to an aspect of the present invention, a livestock wastewater treatment apparatus for treating livestock wastewater, including a total oxygen free tank, an aeration tank, a post oxygen free tank, a membrane separation aeration tank,
An ultrafiltration unit comprising an ultrafiltration membrane for filtering the livestock wastewater passing through the total oxygen free tank, the aeration tank, the rear oxygen free tank, and the membrane separation aeration tank; And a nano reverse osmosis filtration unit comprising a nano membrane and a reverse osmosis membrane that sequentially filter livestock wastewater passing through the ultrafiltration unit.
The nano reverse osmosis filtration unit includes a single vessel, and the nanomembrane and the reverse osmosis membrane are installed together in the single vessel.
In the livestock wastewater treatment apparatus according to another aspect of the present invention, a livestock wastewater treatment apparatus for treating livestock wastewater, including a total oxygen free tank, an aeration tank, a back oxygen free tank, and a membrane separation aeration tank,
An ultrafiltration unit comprising an ultrafiltration membrane for filtering the livestock wastewater passing through the total oxygen free tank, the aeration tank, the rear oxygen free tank, and the membrane separation aeration tank; And a nano reverse osmosis filtration unit comprising a nano membrane and a reverse osmosis membrane that sequentially filter livestock wastewater passing through the ultrafiltration unit.
The nano reverse osmosis filtration unit may include a plurality of containers connected to each other through a channel of the livestock wastewater, and the nano membrane and the reverse osmosis membrane may be divided into the plurality of containers.

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According to an aspect of the present invention, there is provided a method for treating livestock wastewater, the method comprising: treating livestock wastewater via a total oxygen free tank, an aeration tank, a back oxygen free tank, and a membrane separation aeration tank; Filtering livestock wastewater passing through the total oxygen free tank, the aeration tank, the rear oxygen free tank, and the membrane separation aerobic tank via an ultrafiltration membrane; Filtering livestock wastewater via the ultrafiltration membrane through the nanomembrane and reverse osmosis membrane sequentially; And calculating a saturation index (LSI) value of the livestock wastewater passing through the ultrafiltration membrane and the membrane separation aeration tank so that at least one of the membranes is prevented from clogging, and the inorganic acid for pH adjustment so that the saturation index value is negative. It includes; supplying.

According to one aspect of the present invention, there is provided a livestock wastewater treatment apparatus and a method for treating the same, wherein the treated water passing through the ultrafiltration membrane (UF) in the membrane-bound bioreactor is a reverse membrane (RO membrane) in a single filtration system composed of a high pressure pump and a membrane vessel. ) And nano-reverse osmosis filtration unit equipped with a nano-membrane (NF membrane) at the same time, it is possible to minimize the concentration of the concentrated water while maintaining a high quality of the treated water, and to lower the concentration of inorganic ions in the concentrated water, that is, TDS. Therefore, it is possible to achieve a concentrated magnification of 5 times or more at low pressure, and there is an effect of producing a high quality concentrated liquid fertilizer.

According to another aspect of the present invention, the apparatus for treating livestock wastewater and the method of treating the same, the nanomembrane removes around 80% of the total dissolved solids, while monovalent ions have a much lower removal rate of 40-70%, and bivalent or higher inorganic Ions and hardly decomposable organics can be completely processed in excess of 95%, while reverse osmosis membranes can remove more than 99% of monovalent inorganic transition temperatures. The nano reverse osmosis by filtration units place a reverse osmosis membrane at the front end portion and to produce a number of high purity process, by installing a film nano at the rear end portion Cl of relatively present in high concentration in livestock ^waste-1, such as, K ^+, Na ⁺ By discharging ions into the treated water, the total dissolved solids in the concentrate can be lowered. In this single-system nano reverse osmosis filtration unit, the reverse osmosis membrane and the nanomembrane play a complementary role, i.e., in batch filtration, the reverse osmosis membrane improves the treated water quality, and the nanomembrane continuously discharges the concentrated monovalent ions. As a result, it is possible to achieve a concentrated concentration of 5 times higher than that of raw water even at low pressure (25 kgf / cm ² or less), thereby minimizing the generation of concentrated liquid fertilizer, and the produced concentrated liquid fertilizer has a low total dissolved solids, which results in a liquid fertilizer. It is suitable to spray on grassland or farmland.

According to another aspect of the present invention, there is provided a livestock wastewater treatment apparatus and a method for treating the same. Excessive denitrification occurs, which can greatly increase the pH value and alkalinity. The mixed solution in the membrane separation aeration tank is filtered and the Langelier Saturation Index (LSI) is calculated by measuring the pH, related inorganic ion concentrations, and other factors. From the calculated value, a condition in which precipitation of calcium carbonate (CaCO ₃ ) does not occur, that is, a pH value for which the LSI value has a “−” value is calculated. Inorganic acid (sulfuric acid) is supplied to the membrane separation aeration tank so that the calculated pH value is maintained continuously. As a result of operating in this manner, there is an effect that the nanofiltration membrane and the reverse osmosis membrane mounted in the ultrafiltration membrane (UF) and the nano reverse osmosis filtration unit of the membrane-type bioreactor can be stably operated without fouling.

According to another aspect of the present invention, there is provided a livestock wastewater treatment apparatus and a method for treating the same, wherein when the reverse osmosis membrane and the nanomembrane are installed in a single container, the nano reverse osmosis filtration unit can be compactly improved while improving the treatment performance of the nano reverse osmosis filtration unit. There is an effect that can be produced.

According to the livestock wastewater treatment apparatus and the treatment method according to another aspect of the present invention, when the reverse osmosis membrane and the nanomembrane are installed in a plurality of containers, the treatment liquid is filtered while sequentially flowing the membranes. Therefore, it is possible to easily increase the processing capacity of the nano reverse osmosis filtration unit, there is an effect that can be suitable for application to large-scale livestock wastewater treatment plant.

Hereinafter, a livestock wastewater treatment apparatus and a treatment method thereof according to embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a block diagram showing the configuration of a livestock wastewater treatment apparatus according to an embodiment of the present invention.

1, the livestock wastewater treatment apparatus according to an embodiment of the present invention is based on the elements for performing the membrane-bound bioreaction process and the element for performing the nano reverse osmosis filtration process, the characteristics of the wastewater As a pretreatment facility, a solid-liquid separation process may be added.

That is, in the livestock wastewater treatment system, the raw water is separated from the solid-liquid separator (1) → the total oxygen free tank (2) → the intermittent aeration tank (3) → the aeration tank (4) → the humic oxygen tank (5) → the membrane separation aerobic tank (6) → the treatment tank → the nano reverse osmosis Processing is carried out sequentially through the permeation filtration unit 7 to produce a concentrated liquid fertilizer.

The livestock wastewater treatment apparatus according to the present embodiment includes the total oxygen free tank (2), the rear oxygen free tank (5), the aeration tank (4), and the membrane separation aeration tank (6), and treats livestock wastewater as And an ultrafiltration unit comprising an ultrafiltration membrane for filtering livestock wastewater passing through the total oxygen free tank 2, the rear oxygen free tank 5, the aeration tank 4, and the membrane separation aeration tank 6 as components. And a nano reverse osmosis filtration unit 7 including a membrane separation aeration tank 6 and a nano membrane and a reverse osmosis membrane which sequentially filter livestock wastewater via the ultrafiltration unit.

The nanomembrane and the reverse osmosis membrane may be installed together in a single vessel. The reverse osmosis membrane may be disposed at the front side of the container, and the nanomembrane may be disposed at the rear side of the container.

The ultrafiltration unit may be installed in the membrane separation aeration tank (6). It may include a sulfuric acid supply unit (9) for supplying sulfuric acid to the membrane separation aeration tank (6) provided with the ultrafiltration unit.

In the livestock wastewater treatment method according to the present embodiment, the livestock wastewater is treated with the total oxygen free tank (2), the rear oxygen free tank (5), the aeration tank (4), and the membrane separation aeration tank (6). And, filtering the livestock wastewater passing through the total oxygen free tank (2), the rear oxygen free tank (5), the aeration tank (4), and the membrane separation aeration tank (6) through an ultrafiltration membrane, and the ultrafiltration. And filtering the livestock wastewater via the filtration membrane, sequentially passing through the nanomembrane and the reverse osmosis membrane.

It may include the step of supplying inorganic acid (sulfuric acid) to the livestock wastewater through the ultrafiltration membrane and the membrane separation aeration tank.

The inorganic acid may be supplied such that a saturation index value (LSI) of the livestock wastewater passing through the ultrafiltration membrane and the membrane separation aeration tank is supplied so that the saturation index value is negative.

The function of each component of the said livestock wastewater treatment apparatus is demonstrated.

The solid-liquid separator 1 adds a polymer organic coagulant and an inorganic coagulant to agglomerate and dehydrate the solids in raw water to reduce the load of contaminants in the subsequent biological treatment process. As the solid-liquid separator 1, a centrifuge or a belt press may be used.

The total oxygen free tank 2 can remove the nitrate nitrogen contained in the return water conveyed from the rear end of the aeration tank 4 and the membrane separation aeration tank 6 using the organic matter in raw water as a carbon source.

In the intermittent aeration tank (3), aeration and non-aeration are repeated. The nitrate nitrogen produced during the aeration is denitrified during the aeration and reduced and removed by nitrogen (N ₂ ). The ratio between aeration and nonaeration time can be 4: 2 or 6: 2.

The aeration tank 4 is a highly oxidized nitrified and residual ammonia nitrogen (NH ₄ ⁺ -N) and the organic matter in the intermittent aeration tank (3), the oxidized mixed solution is 10 to 15 times the flow rate of the raw water to the total oxygen free tank ( 2) is conveyed inside.

The post-oxygen tank 5 is further denitrified by the endogenous denitrification of the microorganisms in which nitrogen nitrate (NO ₃ ^-- N), which is conveyed inside and is introduced, can be supplied with a small amount of external carbon such as methanol when the nitrogen load is high. have.

The membrane separation aeration tank 6 separates the treated water and microorganisms from which highly contaminants are highly oxidized, and the microorganisms are returned to the total oxygen free tank 2 at the tip of the bioreactor, and the filtered water passing through the membrane is stored in the treatment tank. .

The ultrafiltration membrane (UF) installed in the membrane separation aeration tank (6) has a nominal pore size of 0.04 μm and removes not only bacteria but also most colloidal particles, thus functioning as an optimal pretreatment facility for the nano reverse osmosis filtration unit. can do.

In addition, the microorganisms are filtered and concentrated to be returned to the bioreactor to maintain the microbial concentration (MLSS, Mixed Liquor Suspended Solid) in the aeration tank of 10,000 ~ 13,000mg / l in the bioreactor to ensure stable treatment even under changing conditions such as load fluctuations. .

On the other hand, when the alkalinity or pH in the bioreactor rapidly rises, calcium carbonate (CaCO ₃ ) generated from calcium bicarbonate (Ca (HCO ₃ ) ₂ ) promotes fouling of the membrane, so a pH control system is installed to prevent this. The pH can be adjusted below a certain value.

The nano reverse osmosis filtration unit 7 is a filtration system equipped with a reverse osmosis membrane and a nano membrane in a high pressure pump and a membrane vessel, and increases the emission of inorganic ions to lower the concentration of inorganic total dissolved solids in the concentrate. The filtration pressure can be reduced and the concentration magnification can be increased at the same filtration pressure.

Here, the mounting ratio of the reverse osmosis membrane and the nano-membrane in the pressure vessel depends on the required water quality, and complementary with the membrane-bound bioreactor by removing the hardly decomposable organic substances, colors, and inorganic ions that cannot be removed in the membrane-bound bioreaction process. Have a relationship.

The final treated water can be used as irrigation water, landscaping water, cleaning water, etc., and the concentrate can be fertilized on crops as a liquid fertilizer.

The livestock wastewater treatment device according to the present embodiment has a membrane-bound bioreactor and a nano reverse osmosis filtration unit that treats total phosphorus and total nitrogen as a highly degradable organic material, chromatic material, and nutrient in the treated water.

As shown, the solid-liquid separator (1), the total oxygen free tank (2), intermittent aeration tank (3), aeration tank (4), after oxygen tank (5), membrane separation aeration tank (6), nano reverse osmosis filtration unit (7) In addition, as an auxiliary facility, an external carbon source supply unit 8 and a pH adjusting sulfuric acid supply unit 9 may be added.

The livestock wastewater treatment process using the livestock wastewater treatment apparatus according to the present embodiment having such a configuration will be described.

First, organic and inorganic coagulants are added to the livestock wastewater and coagulated, and then solid-liquid separated by a solid-liquid separator (1) such as a centrifugal dehydrator or belt press, and then the solids are sent to the compost, and the filtrate is a membrane-bound bioreactor (MBR, Membrane). Bio-Reator) is introduced into the total oxygen free tank (2).

In the total oxygen free tank (2), inflow source water is supplied with nitrate nitrogen (NO ₃ -N) in the mixed liquid returned from the aeration tank 4 at a flow rate of 10 to 15 times the raw water and from the membrane separation aeration tank 6 to 3 to 4 times the raw water. Organic matter in (dehydration liquid) is removed as nitrogen gas (N ₂ ) by denitrification microorganisms as a carbon source.

The denitrification reaction is as follows.

^{_{2NO 3 - + 5H 2 → N}} 2 ↑ + 4H 2 O + 2OH -

Next, in the intermittent aeration tank 3, aeration and non-aeration processes are repeated by starting / stopping the oxygen supply blower. During the aeration, the oxidation of organic matter and the nitrification reaction occurs in which ammonia nitrogen (NH ₄ ⁺ -N) is converted to nitrate nitrogen (NO ₃ -N).

Nitrification reaction is as follows.

NH ₄ ⁺ + 2O ₂ → ^{_{NO 3 - + H 2 O +}} 2H + + △ E

In non-aeration, denitrification is carried out using organic matter in which nitrate nitrogen remains as a carbon source and removed from the wastewater.

The ratio between aeration and non-aeration is maintained at a ratio of 4: 2 or 6: 2, and because the concentration of microorganisms is maintained at 10,000 mg / l or more, it does not settle for 2 to 3 hours due to the interference effect between microbial flocs (Floc). There is no need to install a facility.

The mixed liquid passed through the above process is introduced into the aeration tank 4, and in this process, the ammonia nitrogen and the organic substance remain highly oxidized during the continuous aeration for 24 hours. The oxidized mixed solution is returned to the total oxygen free tank 2 evenly for 24 hours at a flow rate of 10 to 15 times the raw water flow rate.

In the after-oxygen tank (5), as in the pre-oxygen tank (2), an underwater mixer is installed to prevent the precipitation of microorganisms, mix the influent, and further remove the nitrate nitrogen remaining in the endogenous denitrification reaction using the microbial cells. When the total nitrogen in the treated water increases, an external carbon source supply unit 8 may be used to supply an external carbon source such as methanol.

Next, in the membrane separation aeration tank 6, complete oxidation of residual organic matter and ammonia nitrogen occurs, and pH adjustment is performed to prevent fouling of the membrane. The ultrafiltration membrane (UF) installed at the rear stage separates the treated water and the microorganism. The separated microorganisms are sent to the total oxygen free tank 2 continuously for 24 hours at a flow rate of 3 to 4 times the raw water, and the filtered treated water is stored in the treated water tank and then filtered by the nano reverse osmosis filtration unit 7.

The nano reverse osmosis filtration unit 7 is operated in a batch (Batch), can be concentrated in the range of 5 to 10 times the flow rate. Reverse osmosis membranes and nanomembrane membranes can be mounted at different ratios in the range of 1: 9 to 9: 1 in consideration of the required water quality and the quality of the concentrated liquid fertilizer. The nano reverse osmosis filtration unit 7 can be equipped with a reverse osmosis membrane and a nano membrane in a single vessel or in a container unit in a single filtration system in a small scale process. On the other hand, in a larger treatment plant, different high pressure pumps may be installed in different series (Block, Train) to simultaneously filter / concentrate the same treatment tank treated water in a batch.

Hereinafter, the configuration of the livestock wastewater treatment apparatus according to an embodiment of the present invention will be described in detail.

Livestock wastewater treatment apparatus using a nano-reverse osmosis filtration unit (7) for highly treating membrane-bound bioreactor and its hardly degradable organic matter, chromatic material, and total phosphorus (TP), total nitrogen (TN) in FIG. As you can see, the nano reverse osmosis system is a solid-liquid separator (1), a total oxygen free tank (2), an intermittent aeration tank (3), an aeration tank (4), a back oxygen tank (5), a membrane separation aeration tank (6) and a batch filtration concentration system. It is comprised by the filtration unit 7.

1 may be a function in actual processing plant of 30m ³ treatment size, capacity and retention time (HRT) of the bioreactor are shown in Table 1.

[Table 1] Membrane bound bioreactor capacity and residence time

fair Effective capacity (m3) Residence time (day) Amenities  Oxygen Tank 106.4 3.5 Underwater mixer  Intermittent aeration 168.2 5.6 Blower  Aeration tank 145.7 4.9 Blower  Humus Oxygen Tank 35.3 1.2 Underwater Mixer External Carbon Source Supply Facility  Membrane Seperation Tank 39.3 1.3 pH adjusting facility ultrafiltration membrane (UF)  Sum 494.9 1 6.5

The livestock wastewater is coagulated by using organic and inorganic flocculant, and then dehydrated using belt press with solid-liquid separator (1). The solids are disposed of as compost and the filtrate is collected in a flow control tank. Inflow.

The supply flow rate is controlled by integrating with a magnetic flowmeter installed in the supply pipe.

The total oxygen free tank (2) is composed of two tanks, each of which has a 3HP and 5HP submersible mixer and agitates the filtrate of livestock wastewater and the return water returned from the aeration tank (4) and the membrane separation aeration tank (6). Was mixed to allow denitrification to occur.

Three 20HPs were installed as a blower for the intermittent aeration tank (3) and the aeration tank (4), one was spared, and one aeration was carried out for aeration / non-aeration, and the oxygen supply diffuser was a membrane-type acid. The organ was used.

In the aeration tank 4, a continuous blower was operated for 24 hours to achieve sufficient nitrification and oxidation of organic matter, and a 2HP conveying pump and a pipe were installed at the rear end so that the nitrified liquid mixture was returned to the total oxygen free tank 2.

Subsequently, the post-oxygen tank (5) was equipped with an underwater mixer of 3HP to allow denitrification without precipitation.

The membrane separation aeration tank 6 was equipped with a 100 L PE sulfuric acid storage tank, two 40 W metered feed pumps, and a pH meter to adjust the pH to below the set pH. The specifications of the submerged hollow fiber ultrafiltration membrane (UF) installed at the rear end of the membrane separation aeration tank 6 are shown in Table 2.

[Table 2] Specifications of Immersion Ultrafiltration Membranes

Item Specifications  Membrane type     Submersible Hollow Fiber  Module number 6  Membrane effective area 23.2m2 / module × 6Module = 139.2m2  Membrane material PVDF  Nominal respect 0.04 μm  Filtration method Immersion Suction Filtration  Operating pressure range 7 to 55 KPa

In order to prevent clogging of the ultrafiltration membrane, a periodic air supply facility was installed under the ultrafiltration membrane, a periodic automatic backwashing facility by a PLC automatic control facility, and a chemical cleaning facility in which NaOCl or citric acid was added to the CIP tank.

By installing a submersible pump 2HP to the microorganisms concentrated by the ultrafiltration membrane to the anoxic tank was returned to the former be conveyed is achieved, the process can was to store alternately by installing a processing tank 2 of 30m ^3.

The treated water stored in the treated water tank was provided with a pipe so that the nano reverse osmosis filtration unit 7 could be filtered / concentrated batchwise. That is, the pumped treated water is pre-filtered by a bag filter and a micro filter, and then pumped into a pressure vessel equipped with a reverse osmosis membrane and a nano-membrane by a high pressure pump (15HP). Filtration, the filtered water was discharged to the treated water, and the concentrated water was again produced and installed in a batch filtration method to be returned to the treated water tank to be filtered repeatedly.

The main specifications of the mounted nanomembrane are shown in Table 3, and the main specifications of the reverse osmosis membrane are shown in Table 4 below.

[Table 3] Nano-Key Specifications

Type shape Spiral wound  Membrane material Composite Polyamide  Effective area 400 ft2 (37.16m2) Performance  Filtration rate (Nominal) 39.7m3 / day  CaCl2 Rejection (Min / Max) 80/92% Application data  Pressure 500 PSI  Maximum Chlorine Concentration <0.1 ppm  pH 3.0 to 10.0  Feed flow 17.0m3 / hr

[Table 4] Main Specifications of Reverse Osmosis Membrane

 Type shape Spiral wound  Membrane material Composite Polyamide  Effective area 365 ft2 (33.9m2) Performance  Filtration Rate (Nominal) 37.9m3 / day  NaCl Rejection 99.5% Application data  Pressure 600 PSI  Maximum Chlorine Concentration <0.1 ppm  pH 3.0 to 10.0

In this facility, reverse osmosis membrane 5 module and nano membrane 3 module were installed, and a separate CIP pump and CIP tank were installed for cleaning after filtration.

The operation example of the livestock wastewater treatment apparatus comprised as mentioned above is demonstrated below.

The livestock wastewater treatment apparatus of the present invention was tested using a membrane-bound bioreactor, a nano-reverse osmosis filtration unit unit (7) which treats highly decomposable organic matter, chromatic substances, and total phosphorus and total nitrogen. Table 5 shows the average concentrations and treatment efficiencies of raw water (dehydration solution) and treated water flowing into the membrane-bound bioreactor after separation.

[Table 5] Raw Water Quality and Pollutant Treatment Efficiency of Livestock Wastewater Treatment System

Item Raw water (dehydration solution) ㎎ / ℓ MBR-treated water ㎎ / ℓ Final treated water mg / l Processing efficiency (%) Public treatment plant discharge standard ㎎ / ℓ  BOD 10,800 8.5 4.1 99.9 < 30  CODMn 9,450 490 27.5 99.7 50  SS 3,250 1.5 0.6 99.9 < 30  T-N 3,150 105 40.5 98.7 60  T-P 192 21.5 0.12 99.9 8

The average BOD and COD _Mn were 10,800 mg / l and 9,450 mg / l, respectively. The organic matters that could be removed by the microorganisms were almost eliminated in the membrane-bound bioreactor. COD _Mn remained about 490mg / l even after treatment with membrane-bound bioreactors, which was almost completely removed by the nano reverse osmosis filtration unit (7) as a non-degradable organic substance, with a high removal of more than 99.9% of BOD and 99.7% of COD _Mn. Showed efficiency.

As for the suspended solids (SS), the average microbial concentration of the membrane separation aeration tank 6 was 12,500 mg / l, and the hollow fiber ultrafiltration membrane (UF) having a nominal pore diameter of 0.04 μm was removed at 2 mg / l or less. Further removal in the subsequent nano reverse osmosis filtration unit 7 shows a removal rate of more than 99%.

In the case of total nitrogen (TN), an average of 3,150 mg / l was introduced and treated in 105 mg / l in a membrane-bound bioreactor, resulting in a removal rate of 96.6%. In this operation, an external carbon source was not supplied separately. Lower feed water quality can be achieved upon feeding.

Total phosphorus (TP) is present mostly in the form of organic phosphorus (P) and phosphorous acid (PO ₄ ^-3 -P), trivalent phosphoric acid and organic phosphorus (P) in the filtration process by the nano reverse osmosis filtration unit (7) High removal rates of more than 99% can be achieved, which can handle almost all of the total phosphorus, the main cause of eutrophication.

The high treatment efficiency of the membrane-bound bioreactor as described above is 10,000 to 13,000 mg of the microbial concentration in the bioreactor by returning 12 times the raw water from the aeration tank 4 applied in this operation and 4 times the membrane separation aeration tank 6. by keeping it high in the / l range.

The aeration / non-aeration time of the intermittent aeration tank (3), in which nitrification and denitrification were alternately performed, was operated at 6/2 hours. During the aeration time, DO exhibited a concentration of 0.8-1.5 mg / l, and the rear aeration tank (4) and the membrane. In the separation aeration tank 6, DO of 2 mg / l or more was maintained.

Analyze the filtrate of the mixed liquor in the membrane separation aeration tank (6) and supply sulfuric acid based on the calculated saturation index (LSI) to keep the pH below 6.7 to prevent membrane clogging and prevent membrane plugging (TMP, Trans-membrane). pressure) was kept stable between 0.1 ~ 0.2 bar.

In addition, in order to prevent clogging of the ultrafiltration membrane, periodic aeration (10 sec / 10 sec) at the bottom of the membrane, automatic backwashing using the water produced by the PLC and the automatic valve, and chemical cleaning were performed three times a week.

The treated water passing through the membrane (UF) having a nominal pore size of 0.04 μm serves as an optimal pretreatment process for the nano reverse osmosis filtration unit with most colloids removed as well as particulate matter, whereas nano reverse osmosis The filtration unit 7 removes inorganic ions such as phosphoric acid (PO ₄ ^-3 -P) and hardly decomposable organic substances that cannot be treated in a membrane-bound bioreactor (MBR), and each process plays a complementary role. have.

The main inorganic ion concentrations in the treated water of membrane-bound bioreactors are shown in Table 6.

[Table 6] Main inorganic ion concentration in membrane-bound bioreactor treated water

Item unit density Item unit density  pH - 6.5 Cl- Mg / l 2560  TDS Mg / l 5,290 NO3- " 372  Na + " 446 SO4-2 " 250  NH4 + " 14.5 Si " 13.8  K + " 1,230 Fe " 1.68  Mg + " 162 Sr " 0.32  Ca + " 87 Ba " ND  F- " ND B " 1.4

UF treated water was stored in two treatment tanks each having a daily residence time (30m ³ ), and then filtered / concentrated in a batch by nano reverse osmosis filtration process and operated at a recovery rate of 80% (5 times concentrated). A final treated water of 24m ³ and concentrated water of 6m ³ were obtained.

In the process, the film inlet side of the pressure was raised at 12kgf / cm ² up to 22.5kgf / cm ² total dissolved solids (TDS) concentration of the concentrate is shown in Table 7.

[Table 7] Nano Reverse Osmosis Filtration Unit Influent and Concentrated Water TDS Concentration and Concentration Ratio

Membrane-bound biological reactor treated water TDS (mg / ℓ) Flow Rate Concentration Magnification Nano Reverse Osmosis Filtration Unit Concentrated Water TDS (mg / L) TDS Reference Concentration Ratio  5,290 5.0 10,850 2.05

-Operating condition: Maximum inlet pressure 22.5kgf / cm ² Drive below.

The concentration of TDS in the concentrate increased only about 2 times, even though the concentration was increased by 5 times because of the large amount of monovalent ions released through the nanomembrane.

As an example that can be compared with the operation example according to the embodiment of the present invention, an operation example in a general facility will be described below.

In the process after membrane separation aeration tank (6), the number of membrane-bound bioreactors can be treated up to 22.5kgf / cm ² only with reverse osmosis membrane. The results of operation at pressure are shown in Table 8, where the amount of concentrated water generated was 12.2m ³ .

[Table 8] Concentrated water TDS and concentration ratio when concentrated by reverse osmosis membrane alone

Membrane-bound biological reactor treated water TDS (mg / ℓ) Flow Rate Concentration Magnification R / O Concentrated Water TDS (mg / l) TDS Reference Concentration Ratio  5,240 2.46 11,810 2.25

As can be seen from Table 8, when only the reverse osmosis membrane is used, the maximum filtration pressure 22.5kgf / cm ² than when the reverse osmosis membrane 5 modules and nano membrane 3 modules in the present invention Only a flow rate concentration of 50% was available at baseline, while the TDS in the concentrate was rather high, making it unsuitable for use as a liquid fertilizer. In order to achieve the same concentration of drainage when only the reverse osmosis membrane is installed, a higher pressure must be applied as the increased osmotic pressure with increasing TDS.

Hereinafter, the prevention of clogging of the ultrafiltration membrane through pH adjustment will be described.

Excessive denitrification may occur temporarily in the anoxic tank (2) during commissioning of membrane-bound bioreactor (MBR) processes, inadequate solid-liquid separation, and normalization after overload, resulting in high pH and alkalinity. Under these conditions, materials such as Ca (HCO ₃ ) ₂ precipitate with calcium carbonate (CaCO ₃ ) within the membrane surface or membrane pore size, causing the membranes of ultrafiltration membranes or nano-reverse osmosis filtration units to be blocked in an instant. Decreases and the TMP rises, making driving difficult.

The results of analyzing the items necessary to calculate the LSI value by filtering the mixed solution in the membrane separation aeration tank (6) without supplying sulfuric acid are shown in Table 9.

[Table 9] Analysis of Mixed Filtrate in Membrane Separation Tank

Item unit density Item unit density  pH - 7.8 SO4-2 Mg / l 190  Mg + 2 Mg / l 118 Alkalinity Mg asCaCO3 / ℓ 596  Ca + 2 “ 97 Si Mg / l 25  NH4 + -N “ 7.2 Mn " 0.54  NO3--N “ 105 TDS " 5,220

_{^{CaCO 3 + H + ↔ Ca +2}} + HCO 3 -

LSI = pHa-pHs

Where pHa = actual pH of water, pHs = pH at saturation.

When calculating LSI value, pHs = 6.78 and LSI value is +1.02, so the ultrafiltration membrane (UF) is operated by supplying sulfuric acid to maintain the pH below 6.7 to maintain LSI value as negative value. ) Was stable in the range of 0.1 ~ 0.2bar, and it operated normally without clogging.

As described above, according to an apparatus for treating livestock wastewater and a method of treating the same according to an aspect of the present invention, the organic matter in the livestock wastewater, as well as the total of the organic matter in the livestock wastewater through a process combination between a membrane-bound bioreactor using a high concentration microorganism and a nano reverse osmosis filtration unit While it is possible to treat nitrogen and phosphorus below the effluent water quality standards in the public treatment plant, the nano reverse osmosis filtration unit can generate concentrated water with the same filtration pressure (25kgf / cm ²⁾ than the conventional reverse osmosis membrane system. It can be reduced to 1/2 or less, and can be used as a liquid fertilizer by significantly lowering the concentration of inorganic ions in the concentrated water.

2 is a view showing a nano reverse osmosis filtration unit applied to the livestock wastewater treatment apparatus according to an embodiment of the present invention.

2, in the nano reverse osmosis filtration unit 7 according to the present embodiment, the reverse osmosis membrane 110 and the nano membrane 120 are sequentially installed in a vessel 100.

The reverse osmosis membrane 110 and the nanomembrane 120 are the reverse osmosis membrane 110 on the front side, based on the direction in which the treatment liquid is fed to the nano reverse osmosis filtration unit 7, the nanomembrane 120 ) Is disposed at the rear side.

The front sealing member 101 is installed between the front outer peripheral surface of the reverse osmosis membrane 110 and the inner peripheral surface of the container 100 to seal between the reverse osmosis membrane 110 and the container 100.

Similarly, a rear sealing member 102 is provided between the rear outer peripheral surface of the nanomembrane 120 and the inner peripheral surface of the container 100 to seal between the nanomembrane 120 and the container 100.

The reverse osmosis membrane 110 and the nanomembrane 120 pass through the treated water pipe 103. The treated water pipe 103 flows through the reverse osmosis membrane 110 and the treated water generated in the nano membrane 120 to be discharged to the outside of the nano reverse osmosis filtration unit 7.

On the other hand, the treatment liquid fed to the nano reverse osmosis filtration unit 7 becomes a concentrated liquid through the reverse osmosis membrane 110 and the nano membrane 120, the nano reverse osmosis filtration through a concentrate pipe 104 It flows out of the unit 7.

In the present embodiment, the reverse osmosis membrane 110 and the nanomembrane 120 are installed in the single container 100. Therefore, while improving the processing performance of the nano reverse osmosis filtration unit 7, the nano reverse osmosis filtration unit 7 can be manufactured compactly.

Hereinafter, a nano reverse osmosis filtration unit applied to a livestock wastewater treatment apparatus according to another embodiment of the present invention will be described. In carrying out this description, description overlapping with the contents already disclosed in the above-described embodiment of the present invention will be replaced with the description thereof, and will be omitted herein.

3 is a view showing a nano reverse osmosis filtration unit applied to the livestock wastewater treatment apparatus according to another embodiment of the present invention.

Referring to FIG. 3, the nano reverse osmosis filtration unit 7 according to the present embodiment includes a first vessel 200 and a second vessel 250.

A plurality of reverse osmosis membranes 210 and 220 are installed in the first vessel 200. Here, a single reverse osmosis membrane may be installed in the first container 200.

In addition, a plurality of nano films 230 and 240 are installed in the second container 250. Here, a single nano film may be installed in the second container 250.

In the above, a plurality of reverse osmosis membranes 210 and 220 are installed in the first vessel 200, and a plurality of nano membranes 230 and 240 are installed in the second vessel 250, but this is illustrative. will be. That is, the reverse osmosis membrane and the nanomembrane may be installed in the first vessel 200 and the second vessel 250, respectively.

201, 202, 251, and 252 illustrated are sealing members installed in the first vessel 200 and the second vessel 250, respectively.

The reference numerals 203 and 253 shown in the figure are treated water pipes through which treated water flows out through the membranes in the first vessel 200 and the second vessel 250, respectively.

The reference numeral 204 shown is a connecting pipe through which the treatment liquid passed through the reverse osmosis membranes 210 and 220 in the first container 200 flows into the second container 250. The treatment liquid introduced into the second container 250 through the connecting pipe 204 is concentrated through the nanomembrane 230 and 240 to become a concentrate.

This concentrate flows out of the nano reverse osmosis filtration unit 7 through the concentrate pipe 254.

In the present embodiment, the reverse osmosis membranes 210 and 220 and the nano membranes 230 and 240 are installed in the plurality of containers 200 and 250, and the liquid to be treated is filtered while sequentially flowing the membranes. Thus, the treatment capacity of the nano reverse osmosis filtration unit 7 can be easily increased, which can be suitable for application to large scale livestock wastewater treatment facilities.

While the invention has been shown and described with respect to specific embodiments thereof, those skilled in the art can variously modify the invention without departing from the spirit and scope of the invention as set forth in the claims below. And that it can be changed. Nevertheless, it will be clearly understood that all such modifications and variations are included within the scope of the present invention.

1 is a block diagram showing the configuration of a livestock wastewater treatment apparatus according to an embodiment of the present invention.

2 is a view showing a nano reverse osmosis filtration unit applied to the livestock wastewater treatment apparatus according to an embodiment of the present invention.

Figure 3 is a view showing a nano reverse osmosis filtration unit applied to the livestock wastewater treatment apparatus according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

1: solid-liquid separator 2: total oxygen free tank

3: intermittent aeration tank 4: aeration tank

5: back oxygen-free tank 6: membrane separation aerobic tank

7: nano reverse osmosis filtration unit 8: sulfuric acid supply unit

9: external carbon source supply unit

Claims (8)

delete In the livestock wastewater treatment apparatus which processes livestock wastewater, including a total oxygen free tank, an aeration tank, a back oxygen free tank, and a membrane separation aerobic tank, An ultrafiltration unit comprising an ultrafiltration membrane for filtering the livestock wastewater passing through the total oxygen free tank, the aeration tank, the rear oxygen free tank, and the membrane separation aeration tank; And And a nano reverse osmosis filtration unit comprising a nano membrane and a reverse osmosis membrane that sequentially filter livestock wastewater passing through the ultrafiltration unit. The nano reverse osmosis filtration unit includes a single vessel, and the nanomembrane and the reverse osmosis membrane are installed together in the single vessel. In the livestock wastewater treatment apparatus which processes livestock wastewater, including a total oxygen free tank, an aeration tank, a back oxygen free tank, and a membrane separation aerobic tank, An ultrafiltration unit comprising an ultrafiltration membrane for filtering the livestock wastewater passing through the total oxygen free tank, the aeration tank, the rear oxygen free tank, and the membrane separation aeration tank; And And a nano reverse osmosis filtration unit comprising a nano membrane and a reverse osmosis membrane that sequentially filter livestock wastewater passing through the ultrafiltration unit. The nano reverse osmosis filtration unit includes a plurality of containers connected to each other through a flow path of the livestock wastewater, wherein the nanomembrane and the reverse osmosis membrane are partitioned and installed in the plurality of containers. The method of claim 2 or 3, Livestock wastewater treatment apparatus, characterized in that the reverse osmosis membrane is disposed on the front side of the nanomembrane based on the flow direction of the livestock wastewater. The method of claim 2 or 3, Livestock wastewater treatment apparatus including an inorganic acid supply unit for supplying an inorganic acid for pH adjustment, so that clogging of at least one of the membranes is prevented. Treating the livestock wastewater via a total oxygen free tank, an aeration tank, a post oxygen free tank, and a membrane separation aeration tank; Filtering livestock wastewater passing through the total oxygen free tank, the aeration tank, the rear oxygen free tank, and the membrane separation aerobic tank via an ultrafiltration membrane; Filtering livestock wastewater via the ultrafiltration membrane through the nanomembrane and reverse osmosis membrane sequentially; And To prevent clogging of at least one of the membranes, the saturation index (LSI) value of the livestock wastewater passing through the ultrafiltration membrane and the membrane separation aeration tank is calculated, and the inorganic acid for pH adjustment is supplied so that the saturation index value is negative. Livestock wastewater treatment method comprising the; delete delete

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