KR102635439B1 - advanced water-treating system - Google Patents

Abstract

The present invention relates to an advanced wastewater treatment system, and more specifically, to an advanced wastewater treatment system (aka KAPHO-RABC) that can increase water treatment efficiency by using eco-friendly filter media and rotating disks.
The advanced wastewater treatment system using an eco-friendly filter media and a rotating disk of the present invention includes an anaerobic tank into which water to be treated flows from a flow rate adjustment tank; a biological reactor into which treatment water flows from the anaerobic tank; an aeration unit for intermittently supplying air to the bioreactor; a solid-liquid separation unit for separating solid-liquid water from the water to be treated flowing from the biological reactor; a treatment water tank into which the treated water passing through the solid-liquid separator flows; and a filter for filtering the treated water flowing from the treatment tank. The bioreactor includes a fixed filter media unit installed in the lower or middle layer, and a rotatable rotating disk unit installed in the upper layer.

Description

Advanced wastewater treatment system using eco-friendly filter media and rotating disk {advanced water-treating system}

The present invention relates to an advanced wastewater treatment system, and more specifically, to an advanced wastewater treatment system (aka KAPHO-RABC) that can increase water treatment efficiency by using eco-friendly filter media and rotating disks.

Methods for treating sewage or wastewater are largely divided into physical and chemical methods and biological methods.

Physical and chemical methods have disadvantages such as being uneconomical, generating secondary pollutants, and not allowing final treatment. Accordingly, in order to solve the problem of physical and chemical treatment, interest in biological treatment methods that do not generate secondary pollutants and are economical has increased.

In the case of biological treatment methods, nitrogen is removed through a nitrification process that converts nitrogen compounds in wastewater into nitrate nitrogen under an aerobic atmosphere and a denitrification process that reduces nitrate nitrogen to nitrogen gas under an anoxic atmosphere, and phosphorus is removed in an anaerobic state. This is achieved through the process of releasing phosphorus through the metabolic activities of microorganisms, allowing microorganisms to consume excess phosphorus under aerobic conditions, and then removing it as sludge.

Among these biological treatment methods, there is a rotating biological contactor (RBC) method in which a rotating disk is brought into contact with the water to be treated.

The rotating disk method is a method of biological water treatment in which a number of disks are installed half-submerged in water and slowly rotated, and wastewater is purified using naturally occurring aerobic organisms.

In the rotating disk method, as the disk rotates, a biofilm is created on the surface of the disk, and as it continues to rotate in this state, the microorganisms ingest organic matter when submerged in water, and when they come out of the water, they receive oxygen from the air and treat wastewater under aerobic conditions. . In addition, when the size of the microorganisms increases due to the activation of microorganisms, they are separated from the disk, mixed with sewage, and moved to the sedimentation basin to settle.

This rotating disk method saves land and energy, and there is no need to artificially supply oxygen, so the equipment is simple and easy to maintain. In addition, it has the advantage of generating less excess sludge and being less sensitive to changes in concentration or flow rate.

A water treatment device using the rotating disk method is disclosed in Republic of Korea Patent No. 10-2335069. The disclosed water treatment device has a rotating shaft installed slightly higher than the water level, and several disks are vertically fixed and rotated on this rotating shaft.

The water treatment device using the conventional rotating disk method is easy to remove organic substances, but has a problem in that the removal efficiency of nitrogen (N) and phosphorus (P) is low (approximately 60% or less).

Specifically, in the case of nitrogen, anoxic conditions are essential during the denitrification reaction, but as the disk repeatedly rotates underwater and on the water surface, oxygen is supplied to the biofilm and continuous anoxic conditions are not established, resulting in a decrease in the efficiency of the denitrification reaction. do. In addition, in the case of phosphorus, phosphorus is removed using phosphorus microorganisms that release phosphorus under anaerobic conditions and store phosphorus under aerobic conditions, but the existing device has a single section and cannot maintain and control anaerobic and aerobic conditions, so phosphorus is removed. There was a problem of low efficiency.

Republic of Korea Patent No. 10-2335069: Rotating disc contact type water treatment device that can improve water pollution in rivers

The present invention was created to improve the above problems, and by additionally installing a ceramic filter medium with microorganisms attached to the lower or middle layer of the biological reactor equipped with a rotating disk, it is possible to sufficiently secure the anoxic conditions necessary for the denitrification reaction. The purpose is to provide a processing system.

In addition, the purpose is to provide an advanced wastewater treatment system that can increase phosphorus removal efficiency by additionally installing a facility with an anaerobic function at the front of the bioreactor.

In order to achieve the above object, the advanced wastewater treatment system using an eco-friendly filter media and a rotating disk of the present invention includes an anaerobic tank into which treated water flows from a flow rate adjustment tank; a biological reactor into which treatment water flows from the anaerobic tank; an aeration unit for intermittently supplying air to the bioreactor; a solid-liquid separation unit for separating solid-liquid water from the water to be treated flowing from the biological reactor; a treatment water tank into which the treated water passing through the solid-liquid separator flows; and a filter for filtering the treated water flowing from the treatment tank. The bioreactor includes a fixed filter media unit installed in the lower or middle layer, and a rotatable rotating disk unit installed in the upper layer.

The fixed filter media unit includes an upper mesh installed across the biological reactor, a lower mesh installed across the biological reactor and spaced downward from the upper mesh, and accommodated between the upper mesh and the lower mesh, and shell powder. It is provided with ceramic media containing .

The rotating disk unit includes a rotating shaft rotatably supported on the side wall of the biological reactor, and disk-shaped disks installed at regular intervals on the rotating shaft so that the lower part is submerged below the water surface and the upper part is exposed above the water surface.

The solid-liquid separation unit includes a separation tank into which water to be treated flows from the biological reactor, and a membrane separation unit installed inside the separation tank to separate solid-liquid from the water to be treated.

The solid-liquid separation unit is a sedimentation tank for separating solid-liquid water from the biological reactor through differences in specific gravity.

It further includes an ozone oxidation means for removing organic substances by bringing the filtered water discharged from the filter into contact with ozone, wherein the ozone oxidation means includes an exterior connected to the filtered water discharge pipe of the filter, an inner pipe installed inside the exterior, and , an ozone supply unit for supplying ozone to the inner tube, a plurality of twist strips arranged at regular intervals on the outer surface of the inner tube and formed long along the longitudinal direction of the inner tube and twisted in a spiral shape, and the twist strips. It is formed at the end of the plate and has sawtooth-shaped irregularities on one surface, and is installed on the inner tube to be located between the twist ribs and has a nozzle part for ejecting ozone flowing into the inner tube to the outside of the inner tube.

As described above, the present invention can increase water treatment efficiency by additionally installing a ceramic filter medium with microorganisms attached to the lower or middle layer of the biological reactor in which the rotating disk unit is installed, thereby sufficiently securing the anoxic conditions necessary for the denitrification reaction.

In addition, the present invention is environmentally friendly by using discarded shells, such as oyster shells, as a material for ceramic filter media.

1 is a diagram schematically showing an advanced wastewater treatment system according to an example of the present invention;
Figure 2 is a cross-sectional view of the fixed filter applied to Figure 1,
Figure 3 is a side view of the rotating disk portion applied to Figure 1,
Figure 4 is a perspective view of the carrier constituting the rotating disk part of Figure 3,
Figure 5 is a perspective view of the membrane separation unit applied in Figure 1,
Figure 6 is a configuration diagram schematically showing an advanced wastewater treatment system according to another example of the present invention;
Figure 7 is a configuration diagram showing the main parts of an advanced wastewater treatment system according to another example of the present invention;
Figure 8 is a cut-away perspective view of Figure 7;
Figure 9 is a cross-sectional view of Figure 7.

Hereinafter, an advanced wastewater treatment system using an eco-friendly filter media and a rotating disk according to a preferred embodiment of the present invention will be described in detail.

Referring to Figures 1 to 5, the advanced wastewater treatment system of the present invention includes an anaerobic tank (10) into which water to be treated flows from the flow rate adjustment tank (1), a biological reaction tank (20) into which water to be treated flows from the anaerobic tank (10), and , an aeration unit for intermittently supplying air to the biological reactor 20, a solid-liquid separation unit for separating solid-liquid water from the treated water flowing from the biological reactor 20, and a treatment water tank into which the treated water that has passed through the solid-liquid separation unit flows. (70) and a filter (75) for filtering the treated water flowing in from the treated water tank (70).

Water to be treated may flow into the flow rate adjustment tank (1) through known pretreatment devices, such as screens and silt tanks. The water to be treated flowing into the flow adjustment tank (1) may be sewage or wastewater. The flow adjustment tank (1) serves to equalize the inflow and contamination load of the water to be treated. A certain amount of water to be treated flows into the anaerobic tank (10) by the pump (3) installed inside the flow adjustment tank (1).

The anaerobic tank 10 is installed at the front of the biological reactor 20. The anaerobic tank 10 is operated under anaerobic conditions and uses microorganisms to release phosphorus up to 3 to 4 times the inflow concentration. The anaerobic tank 10 is equipped with a conventional stirrer for equal distribution. If necessary, an anaerobic tank can be installed optionally. For example, in the case of small amount of water treatment, the anaerobic tank can be omitted, and in the case of large amount of water treatment, the anaerobic tank can be installed.

The bioreactor 20 is installed at the rear of the anaerobic tank 10. An outlet hole 13 is formed at the top of the partition wall formed between the anaerobic tank 10 and the biological reactor 20. Water to be treated flows from the anaerobic tank (10) to the biological reactor (20) through the outflow hole (13). If the anaerobic tank (10) is omitted, the water to be treated can flow directly from the flow rate adjustment tank (1) to the biological reactor (20).

The water to be treated flowing into the biological reactor 20 is subjected to nitrification and denitrification reactions by microorganisms.

The bioreactor 20 is equipped with an aeration unit to create aerated or non-aerated conditions by intermittently supplying air.

The aeration unit includes a blower 23 and an air diffuser 25 connected to the blower 23 and installed in the lower layer of the bioreactor 20. When the blower 23 operates, air is blown out to the lower layer of the bioreactor 20 through the diffuser 25.

The blower 23 can be operated at regular intervals by a timer. For example, intermittent aeration can be performed at regular intervals within 1 to 2 hours of aeration time and 2 to 4 hours of non-aeration time.

In the biological reactor 20, under aerated conditions, that is, under aerobic conditions, excessive intake of phosphorus by microorganisms and oxidation of ammonia nitrogen into nitrate nitrogen occur. In non-aerated conditions, that is, in anoxic conditions, nitrate nitrogen is reduced to nitrogen gas by microorganisms involved in denitrification, thereby removing nitrogen. By this method, nitrogen and phosphorus can be effectively removed by alternating between aerated and non-aerated conditions, thereby inducing excessive intake of phosphorus, nitrification, and denitrification.

A fixed filter media unit 30 and a rotating disk unit 35 are installed inside the biological reactor 20.

The fixed filter unit 30 is fixedly installed in the lower or middle layer of the biological reactor 20. Therefore, the fixed filter unit 30 is always immersed in the water to be treated.

The fixed filter media unit 30 shown includes an upper mesh 31 installed across the biological reactor 20, and a lower mesh 32 installed across the biological reactor 20 and spaced downward from the upper mesh 31. ) and ceramic filter media 34 that are accommodated between the upper mesh 31 and the lower mesh 32 and contain shell powder.

The upper mesh 31 and the lower mesh 32 have a mesh structure with eyes large enough to block the water to be treated from passing through the ceramic filter medium 34.

The ceramic filter medium 34 can be manufactured by firing a mixture of shell powder and binder. For example, a ceramic filter medium can be manufactured by molding a mixture of 30 to 50 parts by weight of binder per 100 parts by weight of shell powder into a sphere and then firing it at 800 to 1000°C for 1 to 3 hours. As a binder, a mixture of polyethylene resin and any inorganic material among red clay, perlite, and bentonite can be used.

The ceramic filter medium 34 has a porous structure with multiple pores formed on the surface and inside. The ceramic filter medium 34 formed in the form of a ball or pellet has characteristics advantageous to the water treatment process, such as low abrasion and high specific surface area, and thus can improve water treatment ability.

Microorganisms attach to and live on the surface of the ceramic filter medium 34. Therefore, the ceramic filter medium 34 serves as a microbial carrier. Microorganisms attached to the ceramic filter medium 34 perform a nitrification reaction in an aerobic state under aerated conditions, and perform a denitrification reaction in an anoxic state under non-aerated conditions.

The rotating disk portion 35 is installed at regular intervals on the rotating shaft 36 and a rotating shaft 36 that is rotatably supported on both side walls of the biological reactor 20, so that the lower part is submerged below the water surface and the upper part is exposed above the water surface. It is provided with disc-shaped disks (37).

The rotation axis 36 is installed horizontally so that it rises slightly above the water level. Although not shown, the rotation shaft 36 is connected to a motor and can rotate.

The disk 37 has a large surface area so that microorganisms can easily adhere to the surface. Microorganisms attach and a biofilm is formed on the surface of the disk 37. In the illustrated example, both sides of the disk 37 have a honeycomb structure in which hexagonal grooves 38 are formed. The disk 37 may be made of synthetic resin material such as nylon, polyolefin, polypropylene, polyethylene, or polyvinyl chloride.

The lower part of the disk 37 coupled to the rotating shaft 36 is submerged below the water surface and comes into contact with the water to be treated. And the upper part of the disk 37 is exposed above the water and comes into contact with air. Since the disk 37 rotates at a constant speed, a specific part of the disk 37 repeats its position underwater and above the water.

When only the rotating disk unit 35 is installed, as the disk 37 repeatedly rotates underwater and on the surface of the water, oxygen is supplied to the biofilm and continuous anoxic conditions are not established, thereby reducing denitrification efficiency. However, since the present invention further installs a fixed filter unit 30 that is always submerged in water, the anoxic condition is sufficiently maintained in the fixed filter unit 30 during non-aeration, thereby improving the denitrification reaction efficiency.

The solid-liquid separation unit separates the water to be treated flowing from the biological reactor 20 into solid-liquid.

The solid-liquid separation unit shown includes a separation tank 50 into which water to be treated flows from the biological reactor 20, and a membrane separation unit 51 installed inside the separation tank 50 to separate solid-liquid water to be treated.

The separation tank 50 is installed at the rear of the bioreactor 20. An outlet hole 21 is formed at the top of the partition wall formed between the separation tank 50 and the biological reactor 20. Water to be treated flows from the biological reactor 20 into the separation tank 50 through the outflow hole 21.

When the suction pump (59) installed on the suction line (57) connected to the membrane separation unit (51) operates, water flows into the separation membrane made of hollow fiber by suction force, and the water flowing into the separation membrane is processed through the suction line (57). It is discharged into the water tank (70). At this time, the water discharged through the suction line 57 is treated water.

The illustrated membrane separation unit 51 includes a support frame 52, a plurality of separation membrane modules 53 installed side by side inside the support frame 52, and ultrasonic waves applied to the separation membrane modules 53 to separate the membrane modules. It has an ultrasonic vibrator (55) for detaching foreign substances attached to (53), and a variable part installed on the support frame (52) to move the ultrasonic vibrator (55). The separation membrane module 53 includes a separation membrane 54 made of hollow fiber.

Since the above-described membrane separation unit 51 has the same configuration as the membrane separation unit disclosed in Republic of Korea Patent No. 10-2225653, detailed description is omitted.

The treatment tank 70 is installed at the rear of the separation tank 50. The treated water separated from solid and liquid flows through the separation membrane unit 51 into the treatment water tank 70.

The treated water flowing into the treatment tank 70 is finally filtered by the filter 75.

The inlet of the filter 75 is connected to the treatment tank 70 by a connection pipe 71. The treated water discharged from the treatment tank 70 flows into the upper part of the filter 75 through the connection pipe 71. A pump may be installed in the connection pipe 71. A filtered water discharge pipe 73 is installed at the lower part of the filter 75. The filtered final treated water can be discharged to the outside through the discharge pipe 73.

The filter 75 has a typical structure in which the inside of the filter tank 76 is filled with a filter material. Sand, activated carbon, ion resin, etc. can be used as filter materials. One type of such filter media may be used alone, or at least two or more filter media may be stacked to form multiple layers.

As a filter, the filtration device disclosed in Republic of Korea Patent No. 10-0676953 can be used.

Meanwhile, the present invention can apply a sedimentation tank as another example of a solid-liquid separation unit.

Referring to FIG. 6, the sedimentation tank 60 is installed at the rear of the bioreactor 20. An outflow hole 21 is formed at the top of the partition wall formed between the sedimentation tank 60 and the biological reactor 20. Water to be treated flows from the biological reactor 20 to the sedimentation tank 60 through the outflow hole 21.

The water to be treated flowing from the bioreactor 20 into the sedimentation tank 60 is separated into solid and liquid due to differences in specific gravity. And the treated water from the solid-liquid separation in the upper layer flows into the treated water tank (70) through the treated water discharge pipe (61). A pump 63 may be installed in the treated water discharge pipe 61.

Meanwhile, the present invention may further include an ozone oxidation means for removing organic substances by bringing the filtered water discharged from the filter into contact with ozone.

Referring to Figures 7 to 9, the ozone oxidation means includes an outer tube (81) connected to the filtered water discharge pipe (73) of the filter, an inner tube (83) installed inside the outer tube (81), and ozone oxidation through the inner tube (83). An ozone supply unit 90 for supplying ozone, and a plurality of twisted ribs 85 arranged at regular intervals on the outer surface of the inner tube 83 and formed long along the longitudinal direction of the inner tube 83 and twisted in a spiral shape. It is installed on the inner pipe 83 to be located between the twist ribs 85 and the uneven plate 87 formed at the end of the twist rib 85 and provided with sawtooth-shaped irregularities 89 on one side, and the inner pipe 83 ) is provided with a nozzle unit 95 for ejecting the ozone flowing into the inner tube 83 to the outside.

The exterior 81 is made of a pipe structure with an empty interior. The inlet of the exterior (81) is connected to the filtered water discharge pipe (73) of the filter. And the outlet of the exterior is connected to the discharge pipe (79). The filtered water discharged through the filtered water discharge pipe (73) flows into the exterior (81).

The inner tube 83 is installed inside the outer tube 81. The inner tube 83 is made of a hollow structure with both sides closed and the inside empty. The outer diameter of the inner tube 83 is smaller than the inner diameter of the outer tube 81. Accordingly, the outer surface of the inner tube 83 is spaced apart from the inner surface of the outer tube 81.

The ozone supply unit 90 is provided with an ozone tank 91 and an injection pipe 92 connecting the ozone tank 91 and the inner pipe 83.

Ozone gas is stored in the ozone tank 91. The ozone gas stored in the ozone tank 91 is supplied into the inner pipe 83 through the injection pipe 92. Although not shown, the injection pipe 92 penetrates the outer pipe 81 and extends into the inner pipe 83. A valve 93 is installed in the injection pipe 92.

The twist rib 85 is formed to protrude from the outer surface of the inner tube 83. In the illustrated example, four twist ribs 85 are formed on the outer surface of the inner tube 83 at 90-degree intervals. The twist rib 85 is formed to be twisted in a spiral shape.

The uneven plate 87 is formed at the end of the twist rib 85. The uneven plate 87 is made of a thin plate shape. The uneven plate 87 is formed long along the twist rib 85. Since the twist rib 85 is formed to be twisted in a spiral shape, the uneven plate 87 is also formed to be twisted in a spiral shape along the twist rib 85. Sawtooth-shaped irregularities 89 are provided on one surface of the uneven plate 87, that is, the surface facing the outer surface of the inner tube 83.

The nozzle unit 95 is installed in the inner tube 83 so as to be located between the twist ribs 85. A plurality of nozzle units 95 are arranged at regular intervals.

The nozzle unit 95 is attached to a nozzle casing 96 coupled to a perforated hole formed in the inner tube 83, a blowout port 97 formed in the nozzle casing 96, and an inner surface of the nozzle casing 96 ( It is provided with a rubber sheet (98) that blocks 97).

The nozzle casing 96 has a hemispherical shape. One side of the nozzle casing 96 is inserted into the perforated hole and coupled thereto. A circular jet 97 is formed at the end of the nozzle casing 96.

The rubber sheet 98 is elastically stretchable. The rubber sheet 98 is attached to the inner surface of the nozzle casing 96 and blocks the jet nozzle 97. A cutting line 99 is formed on the rubber sheet 98. The cutting line 99 is located corresponding to the outlet 97. When the rubber sheet 98 expands, the cutting line 99 opens, and when the rubber sheet 98 contracts to its original shape, the cutting line 99 becomes blocked.

When ozone gas at a certain pressure flows into the inner tube (83) through the injection tube (92), the rubber sheet (98) expands and the cutting line (99) opens, and thus ozone is discharged through the outlet (97). And, if ozone gas does not flow into the inner tube (83), the pressure inside the inner tube (83) decreases and the cutting line (99) is blocked, blocking the filtrate from flowing into the inner tube (83).

The filtered water flowing into the outer pipe (81) through the filtered water discharge pipe (73) flows along the gap between the inner pipe (83) and the outer pipe (81). The filtrated water forms a spiral flow due to the twisted rib 85 formed in a spiral shape. And around the uneven plate 87, a disorderly turbulent flow occurs due to the irregularities 89. The ozone gas ejected through the nozzle unit 95 by this flow can greatly improve the contact efficiency with the filtered water. Therefore, the decomposition effect of organic matter by ozone can be increased.

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

1: Flow adjustment tank 10: Anaerobic tank
20: bioreactor 25: diffuser
30: fixed media part 35: rotating disk part
50: separation tank 51: membrane separation unit
70: Treatment tank 75: Filter

Claims (6)

an anaerobic tank into which water to be treated flows from the flow rate adjustment tank;
a biological reactor into which treatment water flows from the anaerobic tank;
an aeration unit for intermittently supplying air to the bioreactor;
a solid-liquid separation unit for separating solid-liquid water from the water to be treated flowing from the biological reactor;
a treatment water tank into which the treated water passing through the solid-liquid separator flows;
a filter for filtering treated water flowing in from the treatment tank;
and ozone oxidation means for removing organic substances by bringing the filtered water discharged from the filter into contact with ozone,
The bioreactor includes a fixed filter media unit installed in the lower or middle layer, and a rotatable rotating disk unit installed in the upper layer,
The ozone oxidation means includes an outer tube connected to the filtered water discharge pipe of the filter, an inner tube installed inside the outer tube, an ozone supply unit for supplying ozone to the inner tube, and a plurality of ozone oxidation means arranged at regular intervals on the outer surface of the inner tube. The twist strips are formed long along the longitudinal direction of the inner tube and twisted in a spiral shape, and are formed at the ends of the twist ribs and have serrated protrusions on one surface, and are positioned between the twist ribs. A nozzle unit installed in the inner tube and configured to eject ozone flowing into the inner tube to the outside of the inner tube,
The nozzle unit includes a hemispherical nozzle casing coupled to a perforated hole formed in the inner tube, a circular jet nozzle formed at an end of the nozzle casing, and an elastically elastically expandable nozzle attached to the inner surface of the nozzle casing to block the jet. An advanced wastewater treatment system using an eco-friendly filter medium and a rotating disk, comprising a rubber sheet and a cutting line formed on the rubber sheet that opens when the rubber sheet expands and is blocked when the rubber sheet contracts. The method of claim 1, wherein the fixed filter includes an upper mesh installed across the biological reactor, a lower mesh installed across the biological reactor and spaced downward from the upper mesh, and the upper mesh and the lower mesh. An advanced wastewater treatment system using an eco-friendly filter medium and a rotating disk, characterized by comprising ceramic filter media containing shell powder and accommodated therebetween. The method of claim 1, wherein the rotating disk unit includes a rotating shaft rotatably supported on a side wall of the bioreactor, and disk-shaped disks installed at regular intervals on the rotating shaft so that the lower part is submerged below the water surface and the upper part is exposed above the water surface. An advanced wastewater treatment system using eco-friendly filter media and a rotating disk, characterized by being provided. The method of claim 1, wherein the solid-liquid separation unit comprises a separation tank into which water to be treated flows from the biological reactor, and a membrane separation unit installed inside the separation tank to separate solid-liquid from the water to be treated. Advanced wastewater treatment system using disks. The advanced wastewater treatment system using an eco-friendly filter media and a rotating disk according to claim 1, wherein the solid-liquid separation unit is a sedimentation tank for separating solid-liquid from the water to be treated flowing from the biological reactor by differences in specific gravity. delete

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