KR100859416B1 - A method and apparatus for treatment of wastewater in upflow biofilter system using circular intermittent aeration - Google Patents

Abstract

A method and an apparatus for treatment of wastewater are provided to improve quality of treated water and maintain the water quality stably by improving an air purging process in a upflow treatment type backwashing process and by installing the apparatus in rear of existing treatment facilities or connecting the apparatus to the existing treatment facilities. An apparatus(100) for treatment of wastewater by an upflow biofilter system using circular intermittent aeration comprises: a reactor(101) for storing raw water, the reactor including an underdrain(102) installed in an inner lower part of the reactor to store raw water and a synthetic filter media layer(103) positioned in an inner upper part of the reactor; an aerator including an upper aeration part having first and second aeration lines(A01,A02) divided from each other in an upper part of the underdrain, and a lower aeration part having third and fourth aeration lines(A03,A04) divided from each other in the synthetic filter media layer; a first air line(111) on which a first valve member(111a) is installed, and which connects the second and third aeration lines to each other, and a second air line(112) on which a second valve member(112a) is installed, and which connects the first and fourth aeration lines to each other; and a treated water storage tank(105) connected to the reactor to discharge treated water(104). The reactor has an inlet formed on a bottom face thereof such that a raw water supply line(121) having a fourth valve member(121a) and a backwashing water supply line(131) having a third valve member(131a) are connected to the inlet.

Description

 Method and apparatus for upstream biofilm filtration water treatment using circulating intermittent aeration method

The present invention relates to an upflow biofilm filtration water treatment method and apparatus using a circulating intermittent aeration method.

Currently biofilm filtration, that is, biofilters (Biofilter) is widely used at home and abroad because of the excellent treated water quality. In addition, as the treatment water quality is recycled and the legal discharge water quality is strengthened, existing facilities are being renovated and expanded.

It is most desirable to satisfy the above conditions using the existing facilities as much as possible, but most of them require further expansion due to aging and lack of capacity.

Currently, the filter is widely used due to the low operating cost to remove organic matter and suspended solids (SS), but the application limit has been reached due to the strengthening of water quality standards. To cope with this, water treatment facilities such as micro filters are being applied.

However, the removal of organic matter and the removal of suspended solids in this way is good, but there is a problem of maintenance, and since nitrogen cannot be removed, a separate nitrogen treatment apparatus is required to remove it.

In particular, nitrogen is a major factor that causes green algae, causing serious adverse effects such as death of fish and formation of secondary pollutants in the water ecosystem.

In the case of Korea Patent Registration No. 304068, the water treatment consists of a downflow, two oxidation tanks filled with anthracite, a hydrophilic filter for organic matter, suspended solids and nitrification, and a denitrification tank that removes nitrogen by filling sulfur. It consists of a process.

However, as in the patent, a lot of sites are required when the water treatment is carried out step by step in the two processes, and in the case of the denitrification tank, there is a problem in that the filtration resistance is solved due to the dissolution of sulfur components.

In addition, the Republic of Korea Patent Registration No. 433096 is a flow type is a downflow type, and the process of denitrification after filling the sulfur inside the reaction tank and nitrifying the entire aeration in the middle of the filling height. However, this patent also did not consider backwashing using abandoned lines.

Korean Patent Publication No. 2006-106069 refers only to a general air cleaning method for supplying compressed air by using a piping line installed in a lower collecting device area during air cleaning during a backwash process.

In order to solve the above problems, an object of the present invention is to improve the treatment water quality by improving the process of air cleaning during the backwash process of the upflow treatment method, as well as connecting and installing the rear end of the existing treatment facility or the existing facility, and It is to provide a water treatment method and apparatus that can maintain water quality.

The present invention to achieve the above object

To remove organics, suspended solids, nitrification and some nitrogen in the reactor,

Water to be treated flows into the upstream of the reactor,

Passing the water to be treated introduced into the reactor through the lower collecting device,

The water to be treated passing through the lower collecting device is passed through a synthetic filter layer,
The left and right pairs of left and right pairs having left and right pairs of third and fourth aeration lines disposed on top of the lower collecting device and having the number of treatment objects passing through the synthetic filter layer separated from each other and the left and right pairs disposed on the synthetic media layer and divided from each other Discharged after being transferred to the treated water storage tank by the first aeration process and the second aeration process by the upper aeration unit having the first and second aeration lines of
The suspended solids present in the lower part of the reactor is transferred to the synthetic filter bed through air washing using the upper and lower aeration parts used in the aeration process, and backwashing is performed by introducing the washing water from the lower part of the reaction tank.

Through a first aeration process for supplying air through the first air supply line connecting the second aeration line and the third aeration line, and through a second air line connecting the first aeration line and the fourth aeration line Provided is an upflow biofilm filtration water treatment method using a cyclic intermittent aeration method that alternately performs a second aeration process for supplying air.

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At this time, to improve the water quality of the treated water includes a process for removing nitrogen by transferring to the anaerobic tank or anoxic tank through the internal return of the treated water in the treated water storage tank.

In addition, the present invention
A reactor for storing the water to be treated, the reactor including a lower collecting device for storing the water to be treated at the bottom of the inside, and a synthetic filter layer located at the top of the inside of the reactor,
And an aeration device having an upper aeration portion having first and second aeration lines divided from each other on top of the lower collection device, and having a lower aeration portion having third and fourth aeration lines divided from each other in the synthetic media layer. ,
A first air line connecting the second aeration line and the third aeration line to each other, and a second air line connecting the first aeration line and the fourth aeration line to each other,
Provided is an upstream biofilm filtration water treatment apparatus using a circulating intermittent aeration method having a treated water storage tank connected to the reaction tank to discharge the treated water.
In addition, preferably, the water treatment apparatus performs the entire backwashing process by using the first, second, third and fourth aeration lines during backwashing, and any one of two aeration lines installed on the lower collecting device. And performing a first back-air process through any one of the two aeration lines installed in the synthetic filter layer, and performing a second back-air process through the remaining aeration line and the remaining aeration line of the upper aeration part. And backwash water is supplied into the reactor.

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As described above, the removal of organics, suspended solids, nitrification and some nitrogen was carried out simultaneously using synthetic media in accordance with the present invention. In addition, the equipment used at this time can meet the strengthened water quality standards by using the existing treatment facility in conjunction with the existing treatment facility and as a backend facility of the existing treatment facility.

In particular, the amount of backwash was reduced through the stepwise application of air washing during the backwashing process of the upstream biofilm filtration, and the stable water quality was secured by improving the treatment water quality after backwashing of the upflow treatment method.

Hereinafter, the present invention will be described in more detail.

In the water treatment method according to the present invention, the organic material, suspended solids, nitrification and some nitrogen removal are simultaneously performed using synthetic media, thereby satisfying the enhanced water quality standard by using the associated treatment facility and the post treatment facility of the existing treatment facility.

In addition, the water treatment device according to the present invention not only prevents microorganism detachment due to superaeration by applying an upflow type and a cyclic split intermittent aeration method, but also applies stepwise application of air cleaning during the backwashing process of the upflow type biofilm filtration. Through this, there is an advantage of reducing the amount of backwashing and improving the water quality after the backwashing of the upstream treatment method to secure stable water quality.

Hereinafter, a water treatment method and apparatus according to the present invention will be described in more detail with reference to the accompanying drawings.

1 is a schematic diagram showing a water treatment method according to the present invention.

1, the water treatment method according to the invention

To remove organics, suspended solids, nitrification and some nitrogen in the reactor,

(S1) the water to be treated flows into the upstream of the reactor,

(S2) passing the water to be treated introduced into the reaction tank through the lower collecting device,

(S3) passing the water to be treated that has passed through the lower collecting device through the synthetic media layer,

(S4) the water to be treated having passed through the synthetic media is discharged after being transferred to the treated water storage tank after the first aeration process and the second aeration process,

(S5) At this time, the suspended solids present in the lower part of the reactor is transferred to the synthetic filter bed through air washing using the aeration device used in the aeration process, and backwashing is performed by introducing the washing water from the lower part of the reaction tank.

First, the water to be treated is introduced into the upstream of the reactor (S1).

Next, the water to be treated flowing into the upstream passes through the lower collecting device located in the lower portion of the reaction tank (S2).

Next, the water to be treated passing through the lower collecting device is passed through the synthetic filter layer (S3).

The synthetic media layer includes anthracite powder, sulfur powder, and a binding agent, and is manufactured in a granular form. At this time, the synthetic media layer has a high content ratio of powder anthracite and a small content of sulfur powder when the ratio of the binding agent is fixed to the minimum and the organic matter and nitrification are treated a lot.

If a large amount of sulfur powder is consumed in the denitrification reaction, the air gap between the media and the media becomes smaller, and the filtration resistance rapidly increases to increase the number of backwashes. Therefore, the composition ratio of the sulfur powder is bound to maintain the properties of the synthetic media. It is comprised so that a weight ratio of agent may not exceed 2 times or more.

Next, the water to be treated having passed through the synthetic media layer is passed through a first aeration process and a second aeration process to a treated water storage tank and discharged (S4).

The first aeration process and the second aeration process, as will be described later, consists of four aeration line, using the upper and lower aeration section divided into two places. The lower aeration unit is used to transfer the suspended material and the like on the inlet side to the synthetic filter layer, and finally, the suspended material and the overgrown microorganisms are transferred to the outlet using the upper aeration unit installed in the synthetic filter layer.

Next, the backwash inside the reactor is performed (S5).

The backwashing transfers the suspended solids present in the lower part of the reactor to the synthetic media layer through air washing using the aeration device used in the aeration process, and performs the backwashing by introducing the washing water from the lower part of the reaction tank.

As a result, in the conventional upflow backwashing process, a large quantity is required for backwashing, thereby reducing the number of backwashing used during backwashing by backwashing in such a process.

At this time, in order to further improve the water quality of the water to be treated, it is transferred to an anaerobic tank or an anaerobic tank through an internal return to remove nitrogen, and then transferred to a treatment storage tank and discharged.

In the case of the water to be treated, the nitrate nitrogen or ammonia nitrogen is discharged as it is if completely nitrified, and if the nitrification is insufficient, it is discharged after flowing into an anaerobic tank or an anoxic tank such as activated sludge transformation at the front end.

2 is a schematic diagram of a water treatment apparatus used in the present invention. At this time, the reactor is shown in the form of a single reactor for convenience, it can be applied in the form of a continuous reactor as needed.

2, the water treatment apparatus 100,

In order to process the water to be treated is provided with a reactor 101 equipped with an inlet and outlet,
A third valve member 131 to which the treatment object water supply line 121 having the fourth valve member 121a is connected to the inlet formed in the lower surface of the reactor 101 is supplied with the backwash water. The backwash water supply line 131 having a is connected.
The reactor 101 includes a lower collecting device 102 for storing the water to be treated at the lower end of the reactor, a synthetic filter layer 103 disposed at an upper end of the reactor 101, and the lower collecting device ( 102 is provided with a circulating intermittent aeration device including upper and lower aeration portion respectively positioned on the upper and synthetic media layers (103).
Here, the upper aeration portion located in the synthetic media layer 103 has a pair of left and right first and second aeration lines A01 and A02 divided from each other, and the lower aeration portion located in the lower collection device 102 And a pair of divided left and right third and fourth aeration lines A03 and A04.

A treatment water storage tank 105 connected to the reaction tank 101 for discharging the treatment water 104;

The treated water storage tank 105 is connected to the anaerobic tank or anoxic tank 110 by the internal transport.

Referring to FIG. 2, the treated water flows into the lower collecting device 102 of the reaction tank 101 through the inlet.

The treated water that has passed through the lower collecting device 102 is transferred to the synthetic filter layer 103 filled with the synthetic filter, and then subjected to denitrification through aeration.

In particular, the water treatment apparatus according to the present invention is provided with a circulating intermittent aeration device consisting of upper and lower aeration in the reaction tank (101).

The circular intermittent aeration device includes an upper aeration portion and a lower aeration portion, the lower aeration portion is provided with a third, fourth aeration line (A03, A04) divided into two places on the upper portion of the lower collecting device 102, The first and second aeration lines A01 and A02 which are divided into two parts at 1/3 to 1/2 of the total height of the synthetic media layer 103 filled by the lower collecting device 102 based on the water treatment flow are Equipped.
In addition, the second aeration line (A02) on the right side in the drawing and the third aeration line (A02) on the left side in the drawing at the upper aeration part branch from a main air line to which air is supplied, and a first valve. It is connected to the first air line 111 having the member (111a).
In addition, the first aeration line (A01) on the left side of the drawing in the lower aeration section and the fourth aeration line (A04) on the right side in the drawing in the lower aeration section branch from the main air line supplied with air, the second valve It is connected to the second air line 112 having the member (112a).

Figure 3 is a schematic diagram showing a method of supplying aeration air applied to the water treatment device of the present invention.

Referring to FIG. 3, in the circulation intermittent aeration device, aeration air is supplied to the circulation tank 101 in a circulation manner.
That is, as shown in Fig. 3 (a), the lower aeration portion including the third, fourth aeration line (A03, A04) divided into two places is disposed on the upper portion of the lower collecting device 102, the synthesis The third aeration line A03 and the upper aeration part of the lower aeration part are disposed on the filter layer 103 in a state where an upper aeration part including the first and second aeration lines A01 and A02 divided into two positions is disposed. The two aeration lines (A02) are connected to each other by the first air line (111), thereby opening air into the reaction tank (101) through the second and third aeration lines (A02, A03) when the first valve member (111a) is opened. The first aeration process is to be performed.
In addition, as shown in FIG. 3 (b), the fourth aeration line A04 of the lower aeration portion and the first aeration line A01 of the upper aeration portion are connected to each other by a first air line 112. When the second valve member 112a is opened, a second aeration process of supplying air into the reactor 101 through the first and fourth aeration lines A01 and A04 is performed.

The first aeration process and the second aeration process are operated by a PLC equipped with a timer, and the reactor 101 is alternately operated based on the backwash cycle.

In the case of upflow water treatment, the backwashing process sets a constant pressure on the inlet pump side and backwashing proceeds when the pressure is reached. In the case of backwashing, air washing and water washing should be performed to remove excessive suspended substances present in the lower portion of the reaction tank 101. At this time, a large amount of backwashing water is required in order to transfer the suspended solids below the reactor 101 through the synthetic filter layer 103 to the discharge port (not shown).

4 is a schematic diagram showing a backwashing method applied to the water treatment apparatus of the present invention.

Referring to FIG. 4, the water treatment apparatus according to the present invention initially removes four aeration lines A01, A02, A03 and A04 divided into upper and lower aeration as shown in FIG. 4 (a). Simultaneously operate (whole back-air process).

Next, in the middle period, as shown in FIG. 4 (b), the second and third aeration lines A02, A03 and the first reverse air process are disposed on the lower collecting device 102 and the synthetic filter layer 103. Suspended matter and the like under the reactor 101 are transferred to the synthetic media layer 103.

Next, at the end, as shown in FIG. 4 (c), the first and fourth aeration lines A01, A04 and the second back-air process are disposed on the lower collecting device 102 and the synthetic filter layer 103. Suspended matter and overgrown microorganisms are transferred to a separate outlet (not shown).

Subsequently, the treated water stored in the treated water storage tank 105 is supplied to the lower portion of the reaction tank 101 as backwash water through the backwash water supply line 131 when the third valve member 131a is opened, thereby backwashing the reaction tank 101. This reduces the amount of backwashing water used in conventional backwashing and maintains the treated water quality immediately after backwashing.

After the denitrification reaction, the target treated water is connected to the reaction tank 101 and transferred to the treated water storage tank 105 for discharging the treated water and then discharged.

At this time, the denitrification reaction is not enough water is transferred to the anaerobic tank or anoxic tank 110 to the inside of the treated water storage tank 105 to be discharged sufficiently to perform the denitrification process. The anaerobic or anoxic tank 110 uses a process such as activated sludge modification of shear to completely nitrate untreated nitric acid or ammonia nitrogen.

As described above, the method and apparatus for the upflow biofilm filtration water treatment method using the circulating intermittent aeration method according to the present invention uses a synthetic media including a hydrophilic filter media and a sulfur powder and controls the activation of microorganisms by the intermittent aeration method. Suspension, nitrification and further nitrogen removal are carried out simultaneously.

In particular, the water treatment method using the apparatus according to the present invention not only improves the air washing process during the backwash process of the upflow treatment method, but also improves the treatment water quality by connecting and installing the rear end of the existing treatment facility or the existing facility, It is possible to maintain stable water quality.

Hereinafter, the present invention will be described in more detail with reference to the following examples, which are illustrative only for explaining the present invention, and the present invention is not limited thereto.

EXAMPLE

(Comparative Example 1)

An aerobic biofilm filtration tank filled with an anthracite in the form of an upflow stream and a denitrification tank for removing nitrogen were constructed. The retention time of the aerobic biofilm filtration tank was 1.0 hr, and the denitrification tank was 0.3 hr.

At this time, the treated water used was the effluent from the OO sewage treatment plant operated by activated sludge method, and backwashing was performed when the filtration resistance occurred, and the experiment was performed for 6 weeks, and the water treatment results are shown in Table 1 below.

(Example 1)

A reaction tank of the same size as the aerobic biofilm filtration tank used in Comparative Example 1 was used, and the synthetic media was filled, and aeration air line and aeration line were installed at the middle point of the synthetic media.

In this case, the retention time was applied in the same manner as 1.0 hr, and the same experiment was conducted in the same manner as in Comparative Example, and the results obtained are shown in Table 1 below.

division Comparative example Example Influent Aerobic Biofilm Filtration Tank Denitrification Treated water BOD 15 mg / l 5 mg / l 4 mg / l 7 mg / l SS 10 mg / l 4 mg / l 3 mg / l 6 mg / l T-N 20 mg / l 18 mg / l 6 mg / l 9 mg / l NO ₃ -N 5 mg / l 15 mg / l 4 mg / l 6 mg / l NH ₄ -N 14 mg / l 3 mg / l 3 mg / l 2 mg / l Backwash cycle / 2 days / 2 days 1.5 times / day

Referring to Table 1, the embodiment of the present invention is slightly lower in treatment efficiency compared to the comparative example having two reactors, it can be seen that the effect is very excellent when judging using one reactor.

Therefore, it is determined that the water treatment device according to the present invention may be installed at the rear of an existing facility in a region to which an appropriate statutory discharge water quality standard is applied.

1 is a schematic diagram of the water treatment method used in the present invention.

2 is a schematic diagram of a water treatment apparatus used in the present invention.

Figure 3 is a schematic diagram showing a method of supplying aeration air applied to the water treatment device of the present invention.

4 is a schematic diagram showing a backwashing method applied to the water treatment apparatus of the present invention.

`` Explanation of symbols for main parts of drawings ''

100: processing apparatus 101: reactor

102: lower collecting device 103: synthetic filter layer

104: treated water 105: treated water storage tank

A01: first aeration line A02: second aeration line
A03: Abandoned Line 3 A04: Abandoned Line 3

Claims (7)

To remove organics, suspended solids, nitrification and some nitrogen in the reactor, The treated water flows into the upstream of the reactor, Passing the water to be treated introduced into the reactor through the lower collecting device, The water to be treated passing through the lower collecting device is passed through a synthetic filter layer, A lower abandoned portion having a left and right pair of third and fourth aeration lines disposed on the upper portion of the lower collecting device and divided into each other, and the left and right pairs disposed on the synthetic media layer and divided from each other. Discharged after being transferred to the treated water storage tank by the first aeration process and the second aeration process by the upper aeration unit having the first and second aeration lines of The suspended solids present in the lower part of the reactor is transferred to the synthetic filter bed through air washing using the upper and lower aeration parts used in the aeration process, and backwashing is performed by introducing the washing water from the lower part of the reaction tank. Through a first aeration process for supplying air through the first air supply line connecting the second aeration line and the third aeration line, and through a second air line connecting the first aeration line and the fourth aeration line Upflow biofilm filtration water treatment method using a circulating intermittent aeration method alternately performing a second aeration process for supplying air. The method of claim 1, The synthetic media layer is an upflow biofilm filtration water treatment method using a circulating intermittent aeration method, characterized in that the granular form comprising anthracite powder, sulfur powder and a binding agent. The method of claim 1, The method further comprises the step of removing nitrogen by transferring to the anaerobic tank or anoxic tank through the internal return of the treated water in the treated water storage tank. A reactor for storing the water to be treated, the reactor including a lower collecting device for storing the water to be treated at the bottom of the inside, and a synthetic filter layer located at the top of the inside of the reactor, And an aeration device having an upper aeration portion having first and second aeration lines divided from each other on top of the lower collection device, and having a lower aeration portion having third and fourth aeration lines divided from each other in the synthetic media layer. , A first air line connecting the second aeration line and the third aeration line to each other, and a second air line connecting the first aeration line and the fourth aeration line to each other, A treatment water storage tank connected to the reaction tank for discharging the treatment water; Upflow type biofilm filtration water treatment device using circulating intermittent aeration method. delete The method of claim 4, wherein The water treatment apparatus performs a total backwashing process using the first, second, third and fourth aeration lines during backwashing, and any one of the two aeration lines of the lower aeration unit installed on the lower collecting device and the synthetic media layer. The first backwashing air process is performed through any one of the two aeration lines installed in the upper aeration unit, the second backwashing air process is performed through the remaining aeration line and the remaining aeration line of the upper aeration unit, and inside the reactor. Upflow type biofilm filtration water treatment apparatus using a circulating intermittent aeration method, characterized in that for supplying backwash water. The method of claim 4, wherein In addition, the treatment water storage tank is upstream biofilm filtration water treatment apparatus using a circulating intermittent aeration method, characterized in that connected to the anaerobic tank or anaerobic tank.

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