KR102607542B1 - Rain water non-point pollutant reduction facility using hybrid filter media - Google Patents

Abstract

The present invention relates to a pretreatment tank in which rainwater flows into an internal space: a filtration tank equipped with a filter medium to filter rainwater; and a treatment water tank that collects rainwater that has passed through the filter medium, wherein the filter medium is made of a material containing scoria and porous ceramic. The present invention relates to a rainwater non-point pollution reduction facility using a mixed filter medium.

Description

Excellent non-point pollution reduction facility using mixed filter media {RAIN WATER NON-POINT POLLUTANT REDUCTION FACILITY USING HYBRID FILTER MEDIA}

The present invention relates to a rainwater non-point pollution reduction facility using mixed filter media.

Non-point pollution sources refer to sources that emit unspecified water pollutants in unspecified locations such as cities, roads, farmlands, mountains, and construction sites.

Point pollution sources are easy to collect because the outflow path of pollutants is clear, and since the seasonal impact is relatively small, it is possible to predict the amount generated throughout the year, making it easy to design and maintain treatment facilities such as conduits and treatment plants.

On the other hand, non-point pollution sources are difficult to collect because the outflow and discharge routes of pollutants are not clearly distinguished, and the design and maintenance of treatment facilities are difficult because the amount of generation/emission is greatly influenced by weather conditions such as precipitation.

The inventor of the present invention completed the present invention after a long period of time in order to find a rainwater nonpoint pollution reduction facility that can efficiently treat nonpoint pollution sources caused by rainwater using a mixed filter.

The present invention seeks to provide a non-point pollution reduction facility using a filter medium that can efficiently treat non-point pollution sources caused by rainwater.

Meanwhile, other unspecified purposes of the present invention will be additionally considered within the scope that can be easily inferred from the following detailed description and its effects.

According to an embodiment of the present invention, a pretreatment tank in which rainwater flows into the internal space: a filtration tank installed with a filter medium for filtering rainwater; and a treatment tank for collecting rainwater that has passed through the filter medium, wherein the filter medium is made of a material containing scoria and porous ceramic. A rainwater non-point pollution reduction facility using a mixed filter is provided.

The filter medium includes a first layer formed of a porous ceramic material; And it may include a second layer laminated on the first layer and formed of a scoria material.

A support portion is installed at the bottom of the filtration tank, and the filter medium may be seated on the support portion to be spaced apart from the bottom of the filtration tank.

The pretreatment tank is provided with a partition wall that divides the internal space into a sedimentation tank and an inflow tank, and sediment is deposited while rainwater stays in the sedimentation tank. After the rainwater overflows the partition wall and moves from the sedimentation tank to the inflow tank, It can be moved from the inflow tank to the filtration tank.

A pump that discharges rainwater to the outside may be installed in each of the settling tank and the inflow tank.

The pretreatment tank is provided with an inlet through which rainwater flows, and a screen member covering the inlet may be coupled to the inside of the pretreatment tank to filter out contaminants in the rainwater.

It may further include a backwash device for washing the filter medium.

The backwash device may include an air supply unit that blows out air from a lower side of the filter medium toward the filter medium.

The backwash device may include a backwash water supply unit that supplies rainwater collected in the treatment tank to the upper surface of the filter medium.

A water level sensor may be installed in at least one of the pretreatment tank, the filtration tank, and the treatment tank.

According to the rainwater non-point pollution reduction facility using the mixed filter media according to the present invention, pollutants in rainwater can be easily removed.

According to the rainwater non-point pollution reduction facility using the mixed filter media according to the present invention, water treatment efficiency is high and head loss is small.

According to the rainwater non-point pollution reduction facility using the mixed filter media according to the present invention, initial rainwater can be quickly treated.

Meanwhile, it is to be added that even if the effects are not explicitly mentioned herein, the effects described in the following specification and their potential effects expected from the technical features of the present invention are treated as if described in the specification of the present invention.

Figure 1 is a diagram showing a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention.
FIG. 2 is a diagram showing a portion of FIG. 1 in detail.
FIG. 3 is a view showing the top surface of FIG. 2.
Figure 4 is a cross-sectional view of Figure 2.
Figure 5 is a diagram showing a sedimentation tank of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention.
Figure 6 is a diagram showing the inflow tank of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention.
Figure 7 is a diagram showing a filtration tank of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention.
Figure 8 is a diagram showing a treatment tank of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention.
Figure 9 is a diagram showing the filter media of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention.
Figure 10 is a diagram showing a screen member of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention.
Figure 11 is a diagram showing a blower of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention.
Figure 12 is a diagram showing the backwashing process of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention.
The attached drawings are intended as reference for understanding the technical idea of the present invention, and are not intended to limit the scope of the present invention.

In describing the present invention, if it is determined that related known functions may unnecessarily obscure the gist of the present invention as they are obvious to those skilled in the art, the detailed description thereof will be omitted.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, an embodiment of a rainwater non-point pollution reduction facility using a mixed filter according to the present invention will be described in detail with reference to the attached drawings. In the description with reference to the attached drawings, identical or corresponding components are indicated by the same drawing numbers. This will be given and redundant explanations will be omitted.

Figure 1 is a diagram showing a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention. FIG. 2 is a diagram showing a portion of FIG. 1 in detail. FIG. 3 is a view showing the top surface of FIG. 2. Figure 4 is a cross-sectional view of Figure 2.

Figure 5 is a diagram showing a sedimentation tank of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention. Figure 6 is a diagram showing the inflow tank of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention. Figure 7 is a diagram showing a filtration tank of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention. Figure 8 is a diagram showing a treatment tank of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention.

Figure 9 is a diagram showing the filter media of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention. Figure 10 is a diagram showing a screen member of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention. Figure 11 is a diagram showing a blower of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention.

Figure 12 is a diagram showing the backwashing process of a rainwater non-point pollution reduction facility using a mixed filter media according to the present invention.

The present invention relates to a rainwater non-point pollution reduction facility that treats non-point pollution sources caused by rainwater when rainfall occurs. Rainwater can flow into and be treated in a stormwater non-point pollution abatement facility. That is, pollutants such as suspended solids such as sediment in rainwater and nutrients such as nitrogen and phosphorus can be removed through precipitation, filtration and adsorption in the non-point pollution reduction facility according to the present invention. Rainwater treated in this way can be discharged. According to the non-point pollution reduction facility according to the present invention, initial rainwater can be quickly treated.

Referring to Figure 1, the rainwater non-point pollution reduction facility according to the present invention may include a pretreatment tank (100, 200), a filtration tank (300), and a treatment tank (400) as water treatment tanks. The pretreatment tank may include a settling tank 100 and an inflow tank 200. The water treatment tank can be connected to the manhole 10, etc. to receive rainwater. Meanwhile, the water treatment tank can be controlled by being connected to an external control panel (1).

Referring to FIG. 2, the pretreatment tanks 100 and 200, the filtration tank 300, and the treatment tank 400 may be formed as one piece. The sedimentation tank 100 and the inflow tank 200 may be formed as one piece. That is, the sedimentation tank 100, the inflow tank 200, the filtration tank 300, and the treatment tank 400 may be separately provided in one main body. The sedimentation tank 100, the inflow tank 200, and the treatment tank 400 may be sequentially arranged in one direction (forward-backward direction). The main body can be installed on concrete (F2) on rubble pavement (F1).

Referring to FIG. 3, each of the pretreatment tanks 100 and 200, the filtration tank 300, and the treatment tank 400 may be covered with a cast iron lid 500. The cast iron lid 500 may have a trapezoidal longitudinal cross-section. Additionally, rainwater may flow into one side of the pretreatment tank and be discharged into one side of the treatment tank 400, but this is not limited.

Referring to FIG. 4, drainage pipes (L1, L2) and pumps (P1, P2) for drainage are formed in each of the sedimentation tank 100 and the inflow tank 200, and the treatment tank 400 is converted into a filtration tank 300. A moving pipe (L4) and a pump (P3) may be formed as a backwash water supply unit for supplying wash water. Additionally, an air diffuser 340 connected to the blower 2 may be formed in the filtration tank 300 as an air supply unit that supplies air. The filter medium 300F can be cleaned using these configurations.

Hereinafter, the detailed configuration of the rainwater non-point pollution reduction facility according to the present invention will be described.

The pretreatment tank is provided with a space (hereinafter referred to as internal space) to accommodate rainwater, so when rainfall occurs, rainwater can flow into the internal space. Rainfall may flow into manholes, storm drains, etc. (10) and then flow into the pretreatment tank.

The pretreatment tank may be provided with an inlet (T1) through which rainwater flows. The inlet T1 may be formed through the side wall of the pretreatment tank. An inlet pipe may be coupled to the inlet T1.

A screen member 110 that filters contaminants in rainwater may be installed at the inlet T1 of the pretreatment tank. The screen member 110 may be coupled to the inner side of the pretreatment tank to cover the inlet (T1).

The screen member 110 may be implemented in a box shape. The box-shaped screen member 110 may include a rigid bar and a mesh surface. The rigid bar forms a cube-shaped frame, and the mesh surface can be formed of multiple surfaces. Rigid bars can be formed of metal materials such as STS. The mesh spacing of the mesh surface may be 50 mm.

A space may be provided inside the box-shaped screen member. The box-shaped screen member 110 may cover the inlet T1. The upper surface of the box-shaped screen member 110 may be open, but is not limited.

Rainwater enters the pretreatment tank through the inlet (T1), but first passes through the screen member (110). Contaminants in rainwater are filtered by the screen member 110, and the contaminants can be accommodated in the space inside the box-shaped screen member 110.

The screen member 110 may be detachably coupled to the inner side of the pretreatment tank. If the amount of filtered contaminants is large, the screen member 110 can be removed to remove the contaminants.

As shown in FIG. 10(b), the inlet pipe (U1) coupled to the inlet (T1) may extend inside the box-shaped screen member 110.

The pretreatment tank may include a sedimentation tank 100 (silt tank) and an inflow tank 200. The internal space of the pretreatment tank can be divided into two parts. One of the internal spaces of the pretreatment tank may be the sedimentation tank 100, and the other may be the inflow tank 200. The settling tank 100 and the inflow tank 200 may be arranged in the front and rear directions described above. Rainwater may first flow into the settling tank 100 and then flow into the inflow tank 200.

As shown in FIG. 5, the above-described inlet T1 may be formed on the side wall of the sedimentation tank 100. Additionally, the screen member 110 described above may be coupled to the inner surface of the sedimentation tank 100 to be connected to the inlet T1.

A partition wall (first partition wall) W1 may be formed at the bottom of the pretreatment tank. As shown in FIG. 6, the partition wall W1 may be formed to block the flow of rainwater. The partition wall W1 may divide the internal space into two parts, a sedimentation tank 100 and an inflow tank 200. Rainwater may first flow into the sedimentation tank 100 and then pass through or overflow the partition wall (W1) and then flow into the inflow tank 200. The height of the partition wall (W1) may be lower than the height of the inlet (T1) described above.

In the settling tank 100, contaminants with relatively high specific gravity may be deposited. For example, substances such as silt may settle. While rainwater stays in the sedimentation tank 100, substances such as soil and sand may settle. The precipitated material can be called sludge.

The water surface load of the sedimentation tank 100 may be 50.0 ㎥/㎡·h, and the rain water retention time may be 22 minutes, but is not limited.

The inflow tank 200 can accommodate rainwater overflowing from the sedimentation tank 100. Rainwater may temporarily stay in the inflow tank (200) before moving to the next treatment tank, the filtration tank (300).

The filtration tank 300 is installed at the rear end of the pretreatment tank (the rear end of the inflow tank 200) and can filter rainwater. A second partition wall W2 may be installed between the inflow tank 200 and the filtration tank 300. The second partition W2 extends downward from the top, and rain water can move to the lower passage T2 of the second partition W2. However, the shape of the second partition W2 is not limited in the present invention.

A filter medium (300F) may be installed in the filtration tank 300. Rainwater can be filtered while passing through a filter medium (300F). Rainwater flows upward and can pass through the filter medium (300F) while moving upward from the bottom of the filter medium (300F). The upper surface of the filter medium 300F may be located lower than the upper surface of the partition wall W1.

The filter media (300F) can be designed to increase biological decomposition, adsorption, and odor removal efficiency. The filtration efficiency of the filter medium (300F) can be more than 80% based on suspended solids (SS). The linear speed within the filtration tank 300 may be 20 m/hr, but is not limited. The thickness of the filter medium (300F) is 600 mm and can be accommodated in a loss prevention net. The loss prevention net can be made of ex-metal (22 mm × 50.8 mm × 3.2T) and/or PE mesh (1.5 mm ~ 2.0 mm × 1.6T) materials.

The filter medium 300F may be formed of a material containing scoria and porous ceramic. The filter medium 300F may include both a layer formed of a scoria material and a layer formed of a porous ceramic material.

Scoria and porous ceramics are lightweight porous aggregates that can improve the porosity and water permeability of the filter medium (300F) and prevent blockage of pores in the filter medium (300F).

Scoria has alkaline properties and has developed numerous pores, so it has a high specific surface area and porosity, making it easy to attach and immobilize microorganisms and is an advantageous material for inoculating microorganisms. In addition, Scoria has excellent adsorption and sound absorption, is lightweight with a low bulk density, is easy to construct, and is environmentally friendly.

[Table 1] shows the physical and chemical characteristics of scoria.

chemical composition physical properties Silica SiO ₂ 50.48% Bulk Density
(standard density) 2.08g/ ^cm3 Iron Oxide _{Fe2O3 _} 11.79% Bulk Density 1.86g/ ^cm3 Aluminum Oxide Al ₂ O ₃ 15.97% Water Absorption 11.67% Calcium Oxide CaO 4.54% Bulk Density of Aggregate
(unit volume mass) 0.75kg/L Manganese Oxide MnO 0.19% Uniformity Coefficient
(Equality coefficient) 1.37 Potassium Oxide _K2O 1.23% Magnesium Oxide MgO 6.56% Color RED Sodium Oxide Na ₂ O 3.20% Size 2~5mm

Porous ceramics have an excellent ability to remove contaminants through adsorption and biodegradation, and are a lightweight aggregate with a low density, so they have a high absorption rate. In addition, it is economical and environmentally friendly as it uses filter media (300F) by recycling industrial waste. Porous ceramics can remove pollutants through filtration and adsorption mechanisms. Porous ceramics are very effective in reducing SS, turbidity, and particulate heavy metals.

[Table 2] shows the physical and chemical characteristics of porous ceramics.

chemical composition physical properties Silica SiO ₂ 63.22% Bulk Density
(standard density) 1.67g/ ^cm3 Iron Oxide _{Fe2O3 _} 7.83% Bulk Density 1.51g/ ^cm3 Aluminum Oxide Al ₂ O ₃ 18.95% Water Absorption 10.76% Calcium Oxide CaO 3.51% Bulk Density of Aggregate
(unit volume mass) 0.66kg/L Magnesium Oxide MgO 1.45% Uniformity Coefficient
(Equality coefficient) 1.40 Sulphate SO ₂ 1.22% Potassium Oxide _K2O 1.31% Color Gray Titanium Dioxide _Ti2O 1.25% Size 5~10mm

The filter medium 300F includes a first layer 310 formed of a porous ceramic material and a second layer formed of a scoria material, and the second layer 320 may be formed on the first layer.

The thickness of the first layer 310 may be greater than the thickness of the second layer 320. The thickness of the first layer 310 may be twice the thickness of the second layer 320. The first layer 310 may have a thickness of 30 to 50 cm, and the second layer 320 may have a thickness of 10 to 30 cm. For example, the first layer 310 may have a thickness of 40 cm, and the second layer 320 may have a thickness of 20 cm. Accordingly, the filtration efficiency can be secured at more than 80%, while at the same time the head loss can be minimized to less than 5 cm. For example, the filtration efficiency (SS (suspended solids) filtration efficiency) may be 85% and the head loss may be 5 cm.

Specifically, filtration efficiency can be increased by using scoria material in the filter medium (300F). However, as the amount of scoria used increases, filtration efficiency increases, but head loss may increase. In the existing filter medium (300F), head loss may occur due to blockage (contamination) of the filter medium (300F), and as the amount of scoria used increases, head loss may increase.

Therefore, it is desirable to implement a mixed filter medium (300F) by using not only scoria but also a porous ceramic material in the filter medium (300F). In particular, head loss can be reduced by reducing the amount of scoria used and increasing the amount of porous ceramic used accordingly.

[Table 3] shows the filtration efficiency and head loss according to the thickness (ratio) of the first layer 310 formed of a porous ceramic material and the second layer 320 formed of a scoria material in a 60 cm thick filter medium (300F). Shows an example.

Media ratio (thickness) Processing efficiency head loss First layer (porous ceramic): 50 cm
2nd layer (scoria): 10cm 80% 3cm First layer (porous ceramic): 40 cm
2nd layer (scoria): 20cm 85% 5cm First layer (porous ceramic): 30 cm
2nd layer (scoria): 30cm 87% 7cm First layer (porous ceramic): 20 cm
2nd layer (scoria): 40cm 89% 9cm First layer (porous ceramic): 10 cm
2nd layer (scoria): 50cm 91% 11cm

According to [Table 3], when the thickness of the first layer 310 is 40 cm and the thickness of the second layer 320 is 20 cm, the head loss is only 5 cm while securing a treatment efficiency of 85%.

In addition, when the thickness of the first layer 310 is 50 cm and the thickness of the second layer 320 is 10 cm, the head loss is only 3 cm while securing a treatment efficiency of 80%. However, in this case, the second layer 320 may be too thin, so there may be a high possibility that the scoria will be lost.

Meanwhile, when the thickness of the second layer 320 is 30 cm or more, the head loss becomes excessively large, exceeding 7 cm.

That is, in the most preferred example, the first layer 310 may be 40 cm and the second layer 320 may be 20 cm.

Meanwhile, an ultrasonic water level gauge (S) is installed in each of the inflow tank 200 and the filtration tank 300, and the head loss can be confirmed by the water level difference between the two ultrasonic water level gauges (S).

Referring to FIGS. 7 and 9 , the filter medium 300F may be seated on the support portion 330 installed at the bottom of the filtration tank 300. The support portion 330 may include a bent frame. The frame may be formed of L-shaped steel. The support part 330 may be fixedly coupled to the inner surface of the filtration tank 300. As shown in FIG. 9(a), the support portion 330 may be bolted to the inner surface of the filtration tank 300. When the filter medium 300F is seated on the support part 330, the filter medium 300F may be spaced apart from the bottom of the filtration tank 300, as shown in FIGS. 7 and 9(b). That is, a space may be provided between the bottom of the filtration tank 300 and the filter medium 300F. The filter medium 300F may be spaced approximately 400 mm from the bottom of the filtration tank 300, but is not limited thereto.

The treatment tank 400 is a tank that collects rainwater that has passed through the filtration tank 300 and has undergone filtration. A third partition W3 may be installed between the filtration tank 300 and the treatment water tank 400. The third partition W3 extends upward from the bottom, and rainwater can overflow and move into the upper passage T3 of the third partition W3. However, the shape of the third partition W3 is not limited in the present invention.

The height of the third partition W3 may be higher than the upper surface of the filter medium 300F. The height of the third partition W3 may be smaller than the height of the first partition W1.

A certain amount of water collected in the treatment tank 400 may be stored, and the remainder may be discharged. Rainwater stored in the treatment tank 400 can be used for backwashing of the filter medium 300F. Rainwater in the treatment tank 400 may be discharged into external soil, a separate water pipe, a manhole, etc. 30. In particular, when the water level in the treatment tank 400 reaches the full tank, it may be discharged. A water level sensor (LS3) is installed in the treatment tank 400, and can transmit a signal according to a preset water level.

The treatment tank 400 is provided with an outlet T4, and an outlet pipe U4 may be coupled to the outlet T4. As shown in FIG. 8, the outlet T4 is formed through the side wall of the treatment tank 400, and the outlet pipe U4 may be connected to the outlet T4. The height of the outlet T4 may be the same as the height of the third partition W3 or may be lower than the height of the third partition W3.

The surface loading of the treatment tank 400 may be 25.0 m3/m2·h, the capacity may be 8.50 m3, and the backwash supply time may be 120 seconds, but is not limited.

Hereinafter, with reference to FIG. 1, a processing process when rainfall occurs will be described. However, the processing process described below is illustrative and is not limited thereto.

Rainwater first flows into the rainwater manhole (10) and then flows into the sedimentation tank (100) of the pretreatment tank. Rainwater may flow into the sedimentation tank 100 through the inlet pipe (U1) and/or the inlet (T1).

Rainwater passes through the screen member 110, and impurities (coarse impurities) are primarily filtered out of the rainwater. Additionally, as rainwater stays in the sedimentation tank 100, sediment or suspended solids may settle by gravity.

When rainwater is excessively collected in the sedimentation tank 100 (when it reaches full water level), it overflows the partition wall W1 and moves to the inflow tank 200. Rainwater moves to the filtration tank 300 through the lower side of the second partition W2 and is treated while passing through the filter medium 300F. Rainwater is physically and biologically treated as it passes through the filter medium (300F), so suspended solids (SS) and other pollutants in the filter medium (300F) can be reduced.

Rainwater that has passed through the filter medium (300F) overflows the third partition (W3) and is collected into the treatment tank (400). When the treatment tank 400 reaches its full water level, the rainwater collected in the treatment tank 400 is discharged into the rainwater manhole.

The water level of the settling tank 100 may be below the height of the first partition W1. The water levels of the inflow tank 200 and the filtration tank 300 may be the same, but may be less than or equal to the height of the third partition W3.

If the height of the first partition W1 is higher than the third partition W3, the water level in the sedimentation tank 100 may be the highest. The water levels of the inflow tank 200 and the filtration tank 300 may be the same, but may be less than or equal to the height of the third partition W3. The water level of the treatment tank 400 may be less than or equal to the height of the third partition W3, but may be the same as the height of the outlet T4.

The rainwater non-point pollution reduction facility using mixed filter media (300F) according to an embodiment of the present invention may further include a backwash device. The backwash device can wash the filter medium (300F) to prevent blockage of the filter medium (300F). That is, after the filtration process is completed, the backwash device can remove solids in the filter medium (300F).

When the backwashing process is in progress, rainwater in the pretreatment tank (sedimentation tank 100, inflow tank 200) may be drained.

The pretreatment tank may be coupled with drain pipes (L1 and L2) through which collected rainwater is drained. A storage tank or sewage pipe 20 is separately provided outside the pretreatment tank, and the storage tank or sewage pipe 20 can store or collect rainwater drained through the drain pipes L1 and L2. Rainwater stored or collected in the storage tank or sewage pipe 20 may be separately purified.

Drain pipes (L1 and L2) may be coupled to each of the sedimentation tank 100 and the inflow tank 200. Rainwater collected in each of the settling tank 100 and the inflow tank 200 may be drained to the outside through each drain pipe (L1, L2). Draining the rainwater in the settling tank 100 may have the main purpose of excluding stagnant water, and draining the rainwater in the inflow tank 200 may have the main purpose of excluding backwash water. A pump (P1, P2) may be coupled to each drain pipe (L1, L2), and a valve (check valve and/or butterfly valve) may be further coupled thereto.

Meanwhile, water level sensors (LS1, LS2) are installed in each of the sedimentation tank 100 and the inflow tank 200, and can transmit signals according to the preset water level. Drainage of the drain pipes (L1, L2) can be controlled according to signals from the water level sensors (LS1, LS2). A moving pipe (L4) and a water level sensor (LS3) may also be installed in the treatment tank 400.

In addition, the external control panel 1 is connected to the pumps P1 and P2 of the drain pipes L1 and L2 and can control drainage by controlling the operation of the pumps P1 and P2. The operation of the pumps (P1, P2) can be controlled according to the signals from the water level sensors (LS1, LS2).

The backwash device may include an air supply section. The air supply unit may blow air upward from the lower side of the filter medium (300F). That is, the air supply unit can blow out air toward the filter medium (300F). Accordingly, the filter medium (300F) can be air washed. Contaminants in the filter medium (300F) may be removed by air washing.

The air supply unit may be installed within the filtration tank 300. The air supply unit may be installed in the space between the bottom of the filtration tank 300 and the filter medium 300F. The air supply unit may include a diffuser (coarse bubble diffuser, for example, (ϕ170 × 81H)) 340 that provides air bubbles (B).

The backwash device may further include a blower (2). The blower 2 is connected to the diffuser 340 of the air supply unit, and air can be blown out from the diffuser 340 by operating the blower 2. The blower 2 may be installed outside the filtration tank 300. The blower 2 and the diffuser 340 may be connected through an air pipe (L3). A pump and/or valve (check valve and/or butterfly valve) may be coupled to the air pipe (L3). Additionally, an air flow meter may be coupled to the air pipe.

The blower 2 may be located within the case 2a. Referring to FIG. 11, the case 2a is designed to have a roof, the blower 2 can be placed inside, and it can be provided with a door. A locking device may be formed on the door. Case 2a may be fixed to the floor through fastening members such as anchors and bolts. The case may be provided with a flat portion 2b for fastening members such as anchors and bolts, and the flat portion 2b may be located at a corner of the case.

The backwash device may include a backwash water supply unit. The backwash water supply unit may move rainwater collected in the treatment tank 400 to the filtration tank 300 and supply it to the upper surface of the filter medium 300F. The backwash water supply unit may include a moving pipe (L4) that moves rainwater, and a nozzle (N) coupled to the end of the moving pipe (L4). The nozzle (N) is a spiral nozzle, and the spray angle may be 120 degrees. A pump (P3) and/or a valve (check valve and/or butterfly valve) may be coupled to the moving pipe (L4).

Once the rainfall event has ended and disposal of the storm water is complete, the backwash process can begin. That is, as the blower 2 operates, air is ejected from the diffuser 340 toward the filter medium 300F, and/or rainwater collected in the treatment tank 400 moves through the moving pipe L4 to serve as backwash water to the filter medium 300F. It can be sprayed to the (300F) side. Accordingly, the filter medium 300F can be washed.

Hereinafter, with reference to FIG. 12, the backwashing process will be described in detail. However, the processing process described below is illustrative and is not limited thereto.

Figure 12(a) shows a state in which rainfall occurs and rainwater is treated. Stormwater can be treated and discharged.

① 48 hours after the rainfall ends, the backwash process can begin. A rain sensor may be installed inside or outside the control panel 1, and the rain sensor may perform sensing while backwashing is in progress. If rainfall begins again, the backwash may be stopped.

②First, as shown in FIG. 12(b), the sedimentation tank 100 may be drained. Drainage of the sedimentation tank 100 may be stopped after the water level in the sedimentation tank 100 reaches a preset level. Here, the preset height may be the lowest water level.

③Also, drainage of the inflow tank 200 may be performed. Drainage of the inlet tank 200 may be stopped after the water levels in the inlet tank 200 and the filtration tank 300 reach a preset level. Here, the preset height may be the height of the upper surface of the filter medium (300F). Accordingly, the water level of the inlet tank 200 and the filtration tank 300 can be maintained at the height of the upper surface of the filter medium 300F, and the water level of the treatment tank 400 can be maintained at the level of the third partition W3.

④Next, the blower 2 operates so that air can be supplied from the diffuser 340 of the air supply unit to the filter medium 300F. The blower (2) can be operated at 50 m ³ /m ² /min for 120 seconds. Accordingly, air washing of the filter medium (300F) may proceed.

⑤Next, as shown in FIG. 12(c), the inlet tank 200 is drained again and the drain can be stopped at the lowest water level. At this time, the water level of the inlet tank 200 and the filtration tank 300 becomes the lowest water level, but the water level of the treatment tank 400 can be maintained at the level of the third partition W3.

⑥Next, as shown in FIG. 12(d), the backwash water supply unit can supply rainwater in the treatment tank 400 to the upper surface of the filter medium 300F. The pump P3 coupled to the backwash water supply unit can pump the rainwater in the treatment tank 400 to move it to the filtration tank 300. Accordingly, as the filter tank 300 is filled, water washing of the filter medium (300F) can proceed. This supply of backwash water may continue until the water level in the filter tank 300 reaches the height of the upper surface of the filter medium (300F).

⑦Next, the blower (2) can operate again. The blower 2 operates to supply air from the diffuser 340 of the air supply unit to the filter medium 300F. The blower (2) can be operated at 50 m ³ /m ² /min for 120 seconds. Accordingly, air can clean the filter medium (300F). This may be the same as process ④ described above.

⑧Next, the inlet tank 200 is drained again and the drain can be stopped at the lowest water level. This may be the same as process ⑤ described above.

⑨Next, the blower (2) can operate again. This may be the same as processes ④ and ⑦ described above.

⑩Drainage of the inflow tank 200 may be performed again and drainage may be stopped at the lowest water level. This may be the same as processes ⑤ and ⑧ described above.

That is, air washing of the filter medium (300F) according to the air supply unit and water washing of the filter medium (300F) using backwash water are repeated several times. Water washing of the filter medium (300F) can be performed until all the rainwater in the treatment tank (400) is used up. The number of times of air washing and/or water washing of the filter medium (300F) may vary depending on the degree of contamination of the filter medium (300F). For example, two air washes and one water wash may be performed.

⑪ Afterwards, as shown in FIG. 12(e), all rainwater in the filter tank 300 is drained to remove all suspended solids in the filter medium (300F), and the backwashing process is completed, and the filter medium (300F) is returned to its initial state. It can be restored. Accordingly, the filter material (300F) can prepare for the next rainfall.

The above-described treatment of rainwater and washing of the filter medium (300F) can be operated unmanned through automatic operation and can be monitored and controlled to enable central monitoring and management. Additionally, PC/RC construction may be possible depending on site conditions.

The scope of protection of the present invention is not limited to the description and expression of the embodiments explicitly described above. In addition, it is added once again that the scope of protection of the present invention may not be limited due to changes or substitutions that are obvious in the technical field to which the present invention pertains.

100: sedimentation tank
200: Inlet tank
300: Filtration tank
300F: Media
310: first layer
320: second layer
400: Treatment tank
500: Cast iron lid

Claims (10)

Pretreatment tank where rainwater flows into the internal space:
A filtration tank equipped with a filter media that filters rainwater; and
It includes a treatment tank that collects rainwater that has passed through the filter media,
A water level sensor is installed in each of the pretreatment tank, the filtration tank, and the treatment tank,
The pretreatment tank includes a first partition wall that divides the internal space into a settling tank and an inflow tank,
A second partition wall with a passage at the bottom is installed between the inflow tank and the filtration tank,
A pump is installed in each of the settling tank and the inflow tank to discharge rainwater to the outside,
Sediment is deposited while rainwater stays in the sedimentation tank,
The water surface load of the sedimentation tank is 50 m3/m2·h, and the rain water retention time of the sedimentation tank is 22 minutes,
Rainwater overflows the first partition and moves from the settling tank to the inflow tank, and then moves from the inflow tank to the filtration tank through a passage below the second partition,
An ultrasonic water level gauge is installed at the top of the inflow tank and the top of the filter medium of the filtration tank, and the head loss is calculated through the water level difference between the ultrasonic water level gauges,
The filter medium is,
A first layer formed of a porous ceramic material; and
It is laminated on the first layer and includes a second layer formed of a scoria material,
In the filtration tank, rainwater is filtered by passing through the first layer and the second layer in that order,
The thickness of the first layer is greater than the thickness of the second layer,
The thickness of the first layer is 40 cm, the thickness of the second layer is 20 cm,
The filtration efficiency of the filter medium is 85%, the head loss is 5cm,
A support part is installed at the bottom of the filter tank,
The support part is fixed by an L-shaped steel fixedly coupled to the inner surface of the filter tank with bolts,
The first layer is seated on the support so as to be spaced 40 cm from the bottom of the filtration tank,
The sedimentation tank is provided with an inlet through which rainwater flows,
A screen member covering the inlet is detachably coupled to the inner wall of the sedimentation tank to filter out contaminants in rainwater,
The screen member is formed in a box shape with an open upper surface,
The screen member includes a mesh net at 50 mm intervals,
The inlet pipe coupled to the inlet extends into the interior of the screen member,
The water surface load of the treatment tank is 250 m3/m2·h, and the capacity is 850 m3,
Further comprising a backwash device for washing the filter medium,
The backwash device,
an air supply unit that blows out air from a lower side of the filter medium to the first layer side of the filter medium; and
It includes a backwash water supply unit that supplies rainwater collected in the treatment tank to the upper surface of the second layer of the filter medium,
The backwashing process by the backwashing device is started 48 hours after the rainfall ends, but when the rainfall resumes, the backwashing process is stopped,
The backwash process is,
i) Draining all the rainwater in the settling tank, ii) Draining the rainwater in the inlet tank so that the water level in the inflow tank is the height of the upper surface of the filter medium, iii) The air supply unit supplies air to the first layer of the filter medium for 120 seconds while supplying, iv) draining all the rainwater in the inlet tank, v) the backwash water supply unit supplies the rainwater in the treatment tank to the second layer side of the filter medium, where the water level in the inflow tank is the height of the upper surface of the filter medium. characterized by supplying until all rainwater in the inlet tank is drained, vi) all rainwater in the inflow tank is drained, and vii) the above processes iii) to vi) are repeated until all rainwater in the treatment tank is exhausted.
Excellent non-point pollution reduction facility using mixed filter media.
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