KR102122549B1 - water treating apparatus for sewage and wastewater - Google Patents

Abstract

The present invention relates to a water treatment apparatus for sewage and wastewater and, more specifically, to a water treatment apparatus for sewage and wastewater, which processes various kinds of pollutants difficult to process through only a biological reaction process through oxidation and reduction reactions by chemicals to increase the water quality of the finally discharged processed water. According to the present invention, the water treatment apparatus for sewage and wastewater comprises: a solid-request separation unit separating water to be processed into solid and liquid; a biological reaction unit firstly removing ammonia nitrogen included in separated liquid separated by the solid-liquid separation unit by microorganisms; a first precipitation unit firstly precipitating the separated liquid passing through the biological reaction unit; a second precipitation unit inputting a coagulant to a supernatant discharged from the first precipitation unit to perform secondary precipitation; an oxidation unit inputting ozone and an oxidant to the supernatant discharged from the second precipitation unit to oxidize the supernatant; a filtering unit filtering the supernatant passing through the oxidation unit; a reduction unit inputting a reductant to a filtrate discharged from the filtering unit to reduce the filtrate; and a heavy metal filter for removing heavy metal from the filtrate passing the reduction unit.

Description

Water treatment apparatus for sewage and wastewater

The present invention relates to a waste water treatment apparatus, and more specifically, to the water quality of the treated water that is finally discharged through oxidation and reduction reactions of various pollutants that are difficult to treat only by the bioreaction process through chemical reaction. It relates to a water treatment device.

Advanced water treatment refers to an improved water treatment method that simultaneously removes nitrogen and phosphorus components as well as organic substances from sewage/wastewater containing nitrogen and phosphorus.

Removal of nitrogen is carried out through a nitrification process that converts nitrogen compounds in wastewater into nitrate nitrogen in an aerobic atmosphere and a denitrification process that reduces nitrate nitrogen to nitrogen gas under an oxygen-free atmosphere, and the removal of phosphorus, which is usually biological, is performed in an anaerobic state It is achieved through the process of removing phosphorus by the metabolism of microorganisms, and causing the microorganisms to consume excess phosphorus in an aerobic state, then removing it with sludge.

As a measure to improve water quality in public waters that have been rapidly contaminated in recent years, the water environment standards have been gradually strengthened, and it is very important to remove not only organic matter but also nutrient salts (nitrogen, phosphorus, etc.) to improve the water quality of the final discharged water.

In particular, nitrogen and phosphorus compounds in water are pollutants themselves, which also cause loss of water resource value, but are used as nutrients necessary for algal growth, which further deteriorates water quality.

As such, proper removal of nitrogen and phosphorus, which causes eutrophication of coastal waters and coastal waters, is urgently required, but in small and medium-sized treatment facilities, the time to reach sewage is very short compared to large-scale treatment plants, and fluctuations in inflows are daily, weekly, and seasonal. Therefore, it is very difficult to remove nitrogen and phosphorus together, while it is often necessary to maintain a high level of effluent quality, but in the case of conventional small and medium-sized wastewater treatment plants, most of them focus on removing organic and suspended substances. Nitrogen and phosphorus are rarely treated with nutrients.

Among the advanced water treatment methods, the membrane bioreactor (MBR) process is a technology that purifies sewage by applying a separation membrane having micro-sized pores, and can completely filter out particulate contaminants below the micro-unit level in this process. By preventing the loss of microorganisms necessary for purification of pollution, the biological treatment ability is maximized, so the processing speed is faster than the general process. In addition, it can be applied without significant changes to existing biological sewage treatment processes, and it can be said to be a wastewater treatment system that is easy to operate and easy to operate.

However, the separation membrane bioreactor process alone has limitations in treating pollutants such as non-degradable organic and inorganic substances, pesticide components, and heavy metals.

Accordingly, attempts have been made to apply advanced oxidation using ozone (AOP) to bioreaction processes.

Korea Patent Registration No. 10-0992827 discloses a wastewater treatment system, but has a problem in that the water treatment efficiency is lowered due to low oxidation effect due to ozone alone.

Republic of Korea Patent No. 10-0992827: wastewater treatment system

The present invention was created to improve the above problems, and it is a wastewater treatment system that can improve the water quality of treated water that is finally discharged through oxidation and reduction reactions with various pollutants that are difficult to treat with only a bioreaction process. The purpose is to provide.

The waste water treatment apparatus of the present invention for achieving the above object is a solid-liquid separation unit for solid-liquid separation of the water to be treated; A bioreaction unit that primarily removes ammonia nitrogen in the separation liquid separated by the solid-liquid separation unit by microorganisms; A primary sedimentation part that primarily precipitates the separation solution that has passed through the bioreaction part; A secondary sedimentation unit for secondary sedimentation by introducing a coagulant into the supernatant discharged from the primary sedimentation unit; An oxidizing unit that oxidizes the supernatant discharged from the secondary sedimentation unit by introducing ozone and an oxidizing agent; A filtration unit that filters the supernatant that has passed through the oxidation unit; A reducing unit for reducing by introducing a reducing agent into the filtrate discharged from the filtering unit; And a heavy metal filter for removing heavy metals from the filtrate that has passed through the reduction unit.

The bioreactor comprises an anaerobic tank for removing nitric acid nitrogen from the separation liquid, and an aeration tank for aerating nitrogen into the separation liquid flowing out of the oxygen-free tank.

The oxidation unit includes an oxidation tank through which the supernatant discharged from the secondary sedimentation unit flows, an ozone supply unit for injecting ozone into the oxidation tank, and an oxidant supply unit for injecting oxidant into the oxidation tank.

The reduction unit includes a reduction tank through which the filtrate discharged from the filtering unit flows, and a reduction agent supply unit for supplying a reducing agent to the reduction tank.

As described above, the present invention can effectively treat various contaminants that are difficult to treat only by a bioreaction process through oxidation and reduction reactions by chemicals. Accordingly, the water quality of the treated water finally discharged can be improved.

Particularly, the present invention can stably treat nitrogen without being influenced by external change factors such as changes in season or temperature through oxidation and reduction treatment by chemicals, and is also effective in color treatment. In addition, it has a sterilizing and disinfecting effect of the treated water and can provide a safe treated water.

1 is a block diagram schematically showing the configuration of a wastewater treatment system according to an embodiment of the present invention,
2 is a view showing an aggregation reaction tank according to another example of the present invention,
3 is a perspective view excerpting the main portion of FIG. 2.

Hereinafter, a water treatment device for wastewater according to a preferred embodiment of the present invention will be described in detail.

Referring to Figure 1, the waste water treatment apparatus of the present invention is a solid-liquid separation unit for solid-liquid separation of the water to be treated, and a bioreactor for primary removal of ammonia nitrogen in the separation liquid separated by the solid-liquid separation unit by microorganisms Wow, the primary sedimentation part that first precipitates the separation liquid that has passed through the bioreactor, and the secondary sedimentation part that precipitates secondaryly by adding coagulant to the supernatant discharged from the primary sedimentation part, and ozone in the supernatant discharged from the secondary sedimentation part. The oxidizing part to which the oxidizing agent is introduced and oxidized, the filtration part to filter the supernatant that has passed through the oxidizing part, the reducing part to reduce by introducing a reducing agent to the filtrate discharged from the filtration part, and the heavy metal in the filtrate passing through the reducing part A heavy metal filter is provided for removal.

The solid-liquid separator separates the water to be treated into a solid-liquid and separates it into a sludge and a liquid liquid.

The solid-liquid separator includes a storage tank (1) in which the water to be treated is stored, a solid-liquid separator (3) and a solid-liquid separator (3) for solid-liquid separation of the treated water discharged from the storage tank (1) into sludge and separation liquid. ), the separating liquid separated from the collecting tank (5), a coagulant supply unit for injecting a coagulant into the separating liquid of the collecting tank (5), a belt press (7) for separating the separating liquid into which the coagulant is added, and a belt press ( It is provided with a first storage tank (9) through which the separation liquid separated in 7) flows.

The water to be treated flows into the storage tank 1 and is stored in a certain amount. The treatment target water stored in the storage tank 1 is sewage or wastewater. In particular, livestock wastewater is mentioned as wastewater.

The water to be treated stored in the storage tank 1 is first separated into a solid-liquid through the solid-liquid separator 3. As the solid-liquid separator 1, a screen or a centrifugal force separator can be used.

The sludge discharged from the solid-liquid separator 3 may be discarded or stored in a separate sludge tank for composting. And the separation liquid separated from the sludge in the solid-liquid separator (3) flows into the water collecting tank (5). In the separating liquid flowing into the water collecting tank 5, suspended matter is aggregated by the flocculant.

Although not shown, the coagulant supply unit for introducing a coagulant into the water collection tank 5 includes a coagulant storage tank in which coagulants are stored, and a coagulant supply pipe connecting the coagulant storage tank and the water collection tank. The flocculant storage tank stores conventional flocculant for water treatment. For example, alumina sulfate or ferric chloride may be used.

The separating liquid with floc formed by the flocculant is secondarily solid-liquid separated by the belt press 7. The sludge separated from the belt press 7 may be discarded or stored in a separate sludge tank for composting. And the separation liquid separated from the belt press 7 is introduced into the first storage tank 9 and stored.

The bioreactor first removes ammonia nitrogen and nitrate nitrogen from the separation liquid discharged from the first storage tank 9 by microorganisms. Here, the separation liquid means a separation liquid separated from the belt press 7 and stored in the first storage tank 9.

For example, the bioreactor comprises an oxygen-free tank 11 for removing nitric acid nitrogen from the separation liquid, and an aeration tank 13 for aerating nitrogen into the separation liquid flowing out of the oxygen-free tank 11 to oxidize nitrogen.

The oxygen-free tank 11 is installed at the rear end of the first storage tank 9 to remove nitric acid nitrogen in the separation liquid discharged from the first storage tank 9. Of course, the anoxic tank 11 may be provided with a conventional stirrer for equal distribution.

The oxygen-free tank 11 is operated under an oxygen-free condition with an extremely low oxygen concentration, and changes nitrate nitrogen in the separation liquid into nitrogen gas and releases it into the atmosphere. The denitrification reaction may be performed by denitrification microorganisms.

The aeration tank 13 is installed at the rear end of the anaerobic tank 11 to aerate the air into the separation liquid flowing from the anaerobic tank 11 and nitrify nitrogen by microorganisms.

The aeration tank 13 is provided with aeration means for aeration of air therein. Conventional structures can be used as aeration means. Although not shown, the aeration means may be formed of an aeration engine installed inside the aeration tank 13 and a blower for supplying air to the aeration engine.

As described above, the present invention induces oxidation and reduction of nitrogen by microorganisms through anoxic tank 11 and aeration tank 13 to treat nitrogen.

The primary sedimentation part primarily precipitates the separation solution that has passed through the bioreaction part. Here, the separation liquid means a separation liquid separated from the belt press 7 and passed through the anoxic tank 11 and the aeration tank 13.

The primary sedimentation unit includes a primary sedimentation tank 15 connected to the aeration tank 13 and a second reservoir 17 installed at a rear end of the primary sedimentation tank 15.

The primary sedimentation tank 15 is connected to the aeration tank 17, and a separating liquid discharged from the aeration tank 17 flows in. In the primary sedimentation tank 15, the separating liquid is separated by solid-liquid by gravity, and the supernatant located in the upper layer flows into the second storage tank 17 and is stored. And some of the activated sludge in the lower layer is returned to the anoxic tank (11).

The secondary sedimentation unit is precipitated secondaryly by adding coagulant to the supernatant discharged from the second storage tank (17). Here, the supernatant means the supernatant separated from the primary sedimentation tank 15 and stored in the second storage tank 17.

The secondary sedimentation part is connected to the second storage tank (17), and a pressurized floatation tank (19) that floats contaminants in the supernatant, and a third is connected to the pressurized floatation tank (19) and stores the supernatant from which the floated pollutants are removed. The storage tank 21 and the coagulation reaction tank 23 that causes a coagulation reaction by introducing a coagulant into the supernatant discharged from the third storage tank 21, and a secondary sedimentation tank 25 into which the supernatant in which the coagulant is introduced from the coagulation reaction vessel 23 is introduced (25) ).

The pressurized floating tank 19 removes the contaminants in the supernatant flowing from the second storage tank 17 by floating them on the water surface. Contaminants such as suspended solids in the supernatant are attached to the water surface by bubbles generated by the aeration of air in the pressurized floating tank (19). Contaminants that float on the surface can be removed by conventional scum skimmers.

The third storage tank 21 is connected to the pressurized floating tank 19. The supernatant from which the contaminants floating in the pressurized floatation tank 19 is removed is introduced into the third storage tank 21 and stored.

The coagulation reaction tank 23 is connected to the third storage tank 21 and the supernatant is introduced. A coagulant is introduced into the coagulation reaction tank 23 to aggregate contaminants. An agitator for agitating the coagulant with the supernatant may be installed in the coagulation reaction tank 23.

Although not shown, the coagulant supply unit for introducing a coagulant into the coagulant reaction tank 23 includes a coagulant storage tank in which coagulants are stored, and a coagulant supply pipe connecting the coagulant storage tank and the coagulation reaction tank 23. The flocculant storage tank stores conventional flocculant for water treatment.

The supernatant into which the flocculant is added flows into the secondary sedimentation tank (25). In the secondary sedimentation tank 25, the floc formed by the flocculant sinks, and the supernatant is discharged to the oxidation section.

The oxidizing part is oxidized by adding ozone and an oxidizing agent to the supernatant discharged from the secondary sedimentation part.

The oxidation unit supplies an oxidizing tank 27 into which the supernatant discharged from the secondary sedimentation tank 25 flows, an ozone supplying unit for injecting ozone into the oxidizing tank 27, and an oxidizing agent for injecting oxidizing agent into the oxidizing tank 27 Provide wealth.

The oxidation tank 27 is connected to the secondary precipitation tank 25, and the supernatant separated from the secondary precipitation tank is introduced into the oxidation tank 27.

Ozone and an oxidizing agent are supplied to the oxidation tank 27 to chemically oxidize pollutants.

Although not shown, the ozone supply unit for supplying ozone to the oxidation tank 27 includes an ozone tank in which ozone gas is stored, an ozone supply pipe connecting the oxidation tank 27 in the ozone tank, and a valve installed in the ozone supply pipe.

In addition, although not shown, the oxidizing agent supply unit for supplying the oxidizing agent to the oxidizing tank 27 includes a chemical tank in which the oxidizing agent is stored, a chemical supply pipe connecting the oxidizing tank from the chemical tank, and a pump installed in the chemical supply pipe to discharge the chemical. .

As an oxidizing agent, chlorine-based chemicals in aqueous solution can be used. As a chlorine-based chemical, an aqueous solution in which sodium hypochlorite is dissolved in water can be used.

The ozone and oxidizing agent input to the oxidation tank 27 oxidize pollutants with strong oxidizing power. In particular, it effectively promotes nitrification.

The filtering unit removes various contaminants in the supernatant passing through the oxidation unit by filtering and adsorbing them. Here, the supernatant means the supernatant separated from the secondary sedimentation tank 25 and passed through the oxidation tank 27.

As an example of the filtering unit, the supernatant discharged from the oxidation tank 27 flows in and filters the filter tank 29 to filter by the filter, the discharge tank 31 flowing into the filtrate passing through the filter tank 29, and the discharge tank 31 ) And an activated carbon tank 33 for adsorbing contaminants by contacting the filtrate discharged from the activated carbon, and a fourth storage tank 35 in which the filtrate passing through the activated carbon tank 33 is introduced and stored.

The filtration tank 29 is connected to the oxidation tank 27 and the supernatant discharged from the oxidation tank 27 is introduced. A filter is installed inside the filtration tank 29. As a filter, a filter for water treatment can be used. For example, a filter cloth can be used as a filter.

The discharge tank 31 is connected to the filtration tank 29 and the filtrate passing through the filter of the filtration tank 29 flows in.

The activated carbon tank 33 is connected to the discharge tank 31 and the filtrate discharged from the discharge tank 31 flows in. The activated carbon tank 33 is filled with activated carbon. Activated carbon removes contaminants by chemical adsorption as well as physical filtration.

The fourth storage tank 35 is connected to the activated carbon tank 33, and the filtrate passing through the activated carbon tank 33 is introduced and stored.

The reducing unit serves to reduce and remove nitrogen nitrate by adding a reducing agent to the filtrate discharged from the filtering unit.

The reduction unit includes a reduction tank 37 through which the filtrate discharged from the fourth storage tank 35 flows, and a reducing agent supply unit for supplying a reducing agent to the reduction tank 37.

The reduction tank 37 is connected to the fourth storage tank 35 and the filtrate discharged from the fourth storage tank 35 flows in.

Although not shown, the reducing agent supply unit comprises a chemical tank in which the reducing agent is stored, a chemical supply pipe connecting the chemical tank and the reduction tank, and a pump installed in the chemical supply pipe.

Sodium bicarbonate can be used as a reducing agent stored in the chemical tank. Such a reducing agent promotes the reduction of nitrate nitrogen by supplying hydrogen ions in water.

The heavy metal filter 39 removes heavy metals from the filtrate that has passed through the reduction tank 37. As the heavy metal filter 39, a filter for removing heavy metals can be used. The heavy metal filter is effective for removing heavy metals such as nickel and chromium.

The treated water finally passed through the heavy metal filter 39 is discharged to the outside.

As described above, the present invention can effectively treat various contaminants that are difficult to treat only by a bioreaction process through oxidation and reduction reactions by chemicals. Accordingly, the water quality of the treated water finally discharged can be improved.

Particularly, the present invention can stably treat nitrogen irrespective of changes in season or temperature through oxidation and reduction treatment by chemicals, and is also effective in chromaticity treatment. In addition, since it is sterilized and disinfected by an oxidizing agent, it is possible to provide safe treated water.

On the other hand, the present invention is shown in FIG. 2 and FIG. 3 as a coagulant supply unit for injecting a coagulant into the coagulation reactor as another example.

2 and 3, the coagulant supply unit is a coagulant storage tank (60) storing a coagulant, a coagulant storage tank (60) and a coagulant supply pipe (61) connecting the coagulant storage tank (23), and the coagulant supply pipe (61) It is installed in the pump 63 and the coagulant supply pipe 61 installed in the coagulation reaction tank 23 and has a diffusion unit 70 for diffusing the coagulant in water.

The flocculant storage tank 60 stores conventional liquid flocculant. One side of the coagulant supply pipe 61 is connected to the coagulant storage tank 60 and the other side extends into the cohesive reaction tank 23.

The diffusion unit 70 is formed with a receiving chamber 72 so that the flocculant discharged from the flocculant supply pipe 61 flows into the inside, and the injection pipe 71 and the injection pipe 71 in which the discharge ports 73 are formed at regular intervals ) And spaced apart from the injection pipe 71, the ring member 77 is wrapped outside, one side is connected to the outer circumferential surface of the injection pipe 71, and the other side is connected to the inner circumferential surface of the ring member 77 and is twisted in a certain direction. The upper twist member 75 and the discharge port 73 are interposed between the upper twist member 75 and one side is connected to the outer circumferential surface of the injection pipe 71 and the other side is connected to the inner circumferential surface of the ring member 75 The upper twist member 75 and the lower twist member 76 formed to be twisted in the opposite direction, the upper portion of the ring member 77 is formed to be spread outwardly, the upper skirt portion 78, and the ring member 77 It is formed on the lower portion of the lower skirt portion 79 is formed to open out.

The lower portion of the coagulant supply pipe 61 is inserted into the upper inner side of the injection pipe 71 to be combined. The injection pipe 71 and the coagulant supply pipe 61 may be fixed by welding. The injection tube 71 is made of a cylindrical structure with an open top and a closed bottom. Inside the injection pipe 71, a receiving chamber 72 into which a coagulant can be introduced is formed. A plurality of discharge ports 73 are formed in the injection pipe 71. For example, three discharge ports 73 are formed in the injection pipe 71 at 120 degree intervals. The coagulant flowing into the receiving chamber 72 of the injection pipe 71 is discharged to the outside through the discharge port 73.

The ring member 77 is formed in an annular shape to surround the injection tube 71 from the outside. The inner diameter of the ring member 77 is formed larger than the outer diameter of the injection pipe 71.

The ring member 75 is fixed around the injection tube 71 by a pair of upper and lower twist members 75 and 76. The pair of upper twist members 75 and the lower twist members 76 are arranged side by side with the discharge port 73 interposed therebetween. The upper twist member 75 and the lower twist member 76 are formed to be twisted in opposite directions.

When the flocculant is discharged through the discharge port 73, the flow of the flocculant occurs in the opposite direction to each other around the upper twist member 75 and the lower twist member 76, and the flocculant discharged through the discharge port 73 is turbulent. do. And by the upper skirt portion 78 and the lower skirt portion 79, the coagulant rapidly spreads to the surroundings. Therefore, while the flocculant effectively diffuses in water, the mixing efficiency between the liquid and liquid can be greatly increased.

Above, the present invention has been described with reference to one embodiment shown in the drawings, but this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent embodiments are possible therefrom. . Therefore, the true protection scope of the present invention should be defined only by the appended claims.

1: storage tank 3: solid-liquid separator
5: catchment tank 7: belt press
9: First storage tank 11: Anaerobic tank
13: aeration tank 15: primary settling tank
17: second storage tank 19: pressurized floatation tank
21: third storage tank 23: coagulation reaction tank
25: secondary settling tank 27: oxidation tank
29: filtration tank 31: discharge tank
33: activated carbon tank 35: fourth storage tank
37: reduction tank 39: heavy metal filter

Claims (4)

A solid-liquid separator for solid-liquid separation of the water to be treated;
A bioreaction unit that primarily removes ammonia nitrogen in the separation liquid separated by the solid-liquid separation unit by microorganisms;
A primary sedimentation part that primarily precipitates the separation solution that has passed through the bioreaction part;
A secondary sedimentation unit for secondary sedimentation of the supernatant discharged from the primary sedimentation unit into a coagulant in a coagulation reaction tank;
An oxidizing unit that oxidizes the supernatant discharged from the secondary sedimentation unit by introducing ozone and an oxidizing agent;
A filtration unit that filters the supernatant that has passed through the oxidation unit;
A reducing unit for reducing by introducing a reducing agent into the filtrate discharged from the filtering unit;
And a heavy metal filter for removing heavy metals from the filtrate that has passed through the reduction unit.
A coagulant supply unit for introducing a coagulant into the coagulation reaction tank is further provided,
The flocculant supply unit is a flocculant storage tank in which flocculant is stored, a flocculant supply pipe connecting the flocculant storage tank and the flocculant reactor, a pump installed in the flocculant feed pipe, and connected to the flocculant feed pipe to be installed inside the flocculant and coagulant. It has a diffusion unit for diffusing in water,
The diffusion unit is formed with an injection tube having a discharge port formed at regular intervals so that a storage chamber is formed so that the flocculant discharged from the flocculant supply pipe flows into the inside and the flocculant flowing into the accommodation chamber is discharged to the outside, and the injection pipe Spaced apart from the ring member surrounding the injection tube from the outside, one side is connected to the outer circumferential surface of the injection tube, the other side is connected to the inner circumferential surface of the ring member, and the upper twist member formed twisted in a certain direction, with the discharge port therebetween It is installed in parallel with the upper twist member, one side is connected to the outer circumferential surface of the injection tube, the other side is connected to the inner circumferential surface of the ring member, and the lower twist member is twisted in the opposite direction to the upper twist member, and the upper part of the ring member It characterized in that it is formed on the upper skirt portion is formed to spread outwardly, and is formed on the lower portion of the ring member and the lower skirt portion formed to spread outwardly. The method of claim 1, wherein the bioreactor comprises an anaerobic tank for removing nitric acid nitrogen from the separation liquid, and an aeration tank for aeration of nitrogen by aeration of air into the separation liquid flowing out of the anaerobic tank. Water treatment device. According to claim 1, wherein the oxidation unit is characterized in that it comprises an oxidizing tank for introducing the supernatant discharged from the secondary sedimentation unit, an ozone supplying unit for injecting ozone into the oxidation tank, and an oxidizing agent supplying unit for injecting oxidizing agent into the oxidation tank. Wastewater treatment system. The wastewater treatment device of claim 1, wherein the reduction unit includes a reduction tank through which the filtrate discharged from the filtration unit flows, and a reduction agent supply unit for supplying a reducing agent to the reduction tank.

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