KR20220069376A - Method for forming filter in lid facility - Google Patents

Abstract

The present invention relates to method for installing a filter medium in an LID facility, including the steps of: disposing a first layer containing an organic filter medium inside the LID facility; and disposing a second layer including an inorganic filter medium on the first layer. According to the present invention, the filter medium is installed under optimal conditions in the LID facility.

Description

METHOD FOR FORMING FILTER IN LID FACILITY

The present invention relates to a method for installing a filter media in a LID facility.

Social infrastructure refers to the social production base that forms the basis of economic activity, and includes roads, rivers, and water and sewage facilities.

Social infrastructure is shifting from a single function to a multifunctional one with cost-effectiveness and technological advances. In particular, the number of infrastructure facilities with complex functions in consideration of technological development and cost effectiveness, called green infrastructure, is increasing. For example, a sewage treatment facility may include a green space or a function to produce energy. . Such green infrastructure can provide multiple benefits to people and nature.

Green infrastructure may include LID facilities. The LID facility is a facility to which the Low Impact Development technique is applied, and it is a facility that makes the aquatic ecosystem close to the state before urbanization by allowing rainwater to permeate underground.

LID facilities may include soil and media. Soil exerts a function necessary for plant growth, and the filter media can exert a function to filter rainwater.

Accordingly, the inventor of the present invention has researched a method for installing a filter medium in an LID facility for a long time and has completed the present invention after trial and error.

The present invention is to provide a method for installing a filter medium under optimal conditions in a LID facility.

On the other hand, other objects not specified in the present invention will be additionally considered within the range that can be easily inferred from the following detailed description and effects thereof.

According to an embodiment of the present invention, there is provided a method comprising the steps of: disposing a first layer comprising organic media inside a LID facility; and disposing a second layer comprising inorganic media on the first layer.

The second layer may be buried at a depth of 50 cm or more from the ground.

A length of the first layer in a direction parallel to the ground may be 1 m or more.

disposing a gravel layer inside the LID facility; and arranging vegetation soil on the gravel layer, wherein the first layer may be arranged on the vegetation soil.

disposing an additional gravel layer on the second layer; and disposing a wood chip layer on the additional gravel layer.

The pores of the second layer may be larger than the pores of the first layer.

According to the filter media installed in the LID facility according to the present invention, rainwater in the target area can be managed as an optimal LID facility.

On the other hand, even if it is an effect not explicitly mentioned herein, it is added that the effects described in the following specification expected by the technical features of the present invention and their potential effects are treated as described in the specification of the present invention.

1 is a view showing an ecological LID design method according to an embodiment of the present invention.
2 is a view showing a filter media installed in the LID facility according to an embodiment of the present invention.
3 is a view showing an example of a filter medium according to an embodiment of the present invention.
4 is a view showing a reaction between an inorganic filter medium and an organic filter medium according to an embodiment of the present invention.
It is revealed that the accompanying drawings are exemplified by reference for understanding the technical idea of the present invention, and the scope of the present invention is not limited thereby.

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

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, an embodiment of the filter media installed in the LID facility according to the present invention will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, the same or corresponding components are given the same reference numbers and A duplicate description will be omitted.

1 is a view showing an ecological LID design method according to an embodiment of the present invention. 2 is a view showing a filter media installed in the LID facility according to an embodiment of the present invention.

The ecological LID design method according to FIG. 1 is a method for establishing a LID facility in a target area, and the LID facility is a facility to which the LID technique is applied.

LID facilities can be classified into vegetation retention type, infiltration type, filtration type, wetland type, etc. depending on their main function It is a facility. Infiltration type is a facility that allows rainwater to penetrate underground through the unsaturated stratum to obtain the effect of filtration and adsorption. Filtration type is a facility that obtains a filtration effect through sand and filter media. It is a facility that uses plants and microorganisms as a mechanism to reduce pollutants as it is effective for circulation.

Specific LID facilities are vegetation retention type, such as Bioretention Basin, Bio swale, and Planter box, and infiltration type: Infiltration trench, Bio slope, There are permeable pavement, etc., and there are tree box filter and sand filter for filtering type, and artificial wetland for wetland type, small wetland for roadside, rain garden. etc.

However, the type of LID facility is not limited in the present invention, and any facility using the LID technique in addition to the above-described specific LID facility may be included in the present invention.

A LID facility may be established in a specific area defined as a target area. The present invention provides a design method for establishing a LID facility in a target area. The target area may be at least a partial area such as a city, and the city may be a new city or an existing city.

A filter medium may be provided in the LID facility according to FIG. 2 by the ecological LID design method according to FIG. 1 . Hereinafter, with reference to FIG. 2 , a method for installing a filter medium in an LID facility will be described first.

Referring to FIG. 2 , a method for installing a filter medium in an LID facility 100 according to an embodiment of the present invention includes disposing a first layer 110 including an organic filter medium inside the LID facility; and disposing a second layer 120 including an inorganic filter material on the first layer 110 .

The organic filter media is a filtering member containing organic matter, a natural polymer material; synthetic polymers such as acrylamide, phenolic resin, and PS; Eco-friendly natural filter media such as cockle shells, walnut shells and ginkgo shells; tree; wood chips; It may include at least one of a mixture of a small amount of sawdust, fallen leaves, rice husk, etc. added to the wood pieces.

However, the organic filter media is not limited to those described above, and any filtering member including an organic material may be applied to the present invention.

The first layer 110 is a filter media layer including organic media, and may include only organic media, or may be mixed with inorganic media in a relatively smaller ratio than organic media.

The inorganic filter media is a filtering member that does not include organic matter, and may include at least one of sand, gravel, activated carbon, volcanic rock, alumina, glass, ceramic, bottom ash, and zeolite.

However, the inorganic filter media is not limited to the above-mentioned, and any filtering member that does not contain organic material may be applied to the present invention.

3 is a view showing an example of filter media according to an embodiment of the present invention. 3 shows examples and actual photos of organic and inorganic media.

The second layer 120 is a filter media layer including inorganic media, and may include only inorganic media, or may be mixed with organic media in a relatively smaller ratio than inorganic media.

4 is a view showing a reaction between an inorganic filter medium and an organic filter medium according to an embodiment of the present invention.

Referring to FIG. 4 , the nitrification reaction occurs in the inorganic filter media, and the denitrification reaction occurs in the organic filter media. Therefore, the inorganic filter media may be disposed on the upper part and the organic media media may be disposed on the lower part.

Rainwater flowing into the LID facility can be moved in the order of inorganic media and organic media.

The inorganic media may be porous. The pores of the inorganic media may be larger than the pores of the organic media. Accordingly, the pores of the second layer 120 may be larger than the pores of the first layer 110 . The voids of the first layer 110 may be 0.5 or more.

The filter media of LID facilities can be installed at a depth of 50 cm or more from the ground. That is, the second layer 120 may be buried at a depth of 50 cm or more from the ground. In addition, the length of the first layer 110 (and the second layer 120 ) in a direction parallel to the ground may be 1 m or more.

On the other hand, the method of installing a filter medium in the LID facility according to an embodiment of the present invention, comprising the steps of arranging a gravel layer (S1) inside the LID facility; and arranging vegetation soil (S) on the gravel layer (S1), wherein the first layer 110 may be arranged on the vegetation soil (S).

That is, in the LID facility, from bottom to top, the gravel layer (S1), the vegetation soil (S), the organic filter media (the first layer 110), and the inorganic filter media (the second layer 120) can be stacked in this order.

The vegetation soil S may provide nutrients, moisture, microorganisms, etc. to the growth of the plant 20 , and support the plant 20 . The gravel layer (S1) can permeate and filter rainwater. A drain pipe 30 may be connected to the gravel layer S1.

Rainwater flowing into the LID facility is moved in the order of inorganic filter media, organic media, vegetation soil (S), and gravel layer (S1), and can be collected into the rainwater conduit 40 through the drain pipe 30 (W).

On the other hand, the method of installing the filter media in the LID facility according to an embodiment of the present invention comprises the steps of arranging an additional gravel layer (S2) on the second layer (120); and disposing a wood chip layer (S3) on the additional gravel layer (S2).

Accordingly, in the LID facility, from bottom to top, gravel layer (S1), vegetation soil (S), organic media (first layer 110), inorganic media (second layer 120), additional gravel layer (S2) , the wood chip layer S3 may be stacked in this order.

The additional gravel layer (S2) can permeate and filter rainwater. The rainwater inlet pipe 10 may be connected to the additional gravel layer S2. Rainwater flowing in through the rainwater inlet pipe 10 is moved in the order of the additional gravel layer (S2), inorganic media, organic media, vegetation soil (S), and gravel layer (S1), and through the drainage pipe 30, the rainwater pipe (40) ) can be collected.

The wood chip layer (S3) may be located on the uppermost floor in the LID facility, and when the LID facility is a wooden filter box, the wood chip layer (S3) may fill the freshwater depth of the wood filter box. The wood chip layer S3 may function for the safety of pedestrians on the ground and suppression of weed growth.

Referring back to FIG. 1, the ecological LID design method according to an embodiment of the present invention includes the steps of determining the size of the LID facility (S100), analyzing the properties and concentrations of non-point pollutants (S200), non-point pollutants Step (S300) of determining a reduction mechanism for reducing S500), it may include a step (S600) of drawing a target area in which the LID facility is established.

The step of determining the size of the LID facility ( S100 ) is a step of calculating the size of the LID facility to be installed in the target area. In this step, the size of the LID facility can be calculated in consideration of the target reduction rate of rainfall runoff. Rainfall runoff can be calculated through rainfall analysis.

Here, in the case of targeting existing cities other than newly developed new cities, the LID scale can be calculated by selecting the accumulated rainfall corresponding to the 90% occurrence frequency as the rainfall amount to be managed through rainfall analysis.

In particular, in the case of a newly developed new city, the size of the LID can be calculated so that water circulation before development is possible even after development. This can be expressed as an expression as follows.

Design volume criteria of LID (m ³ ) = α(RV _after - RV _before - V _use )

Here, α is the reduction coefficient (constant), RV _after is the amount of rainfall runoff after development (m ³ ), RV _before is the rainfall runoff before development (m ³ ), and V _use means the amount of rainfall used (m ³ ).

On the other hand, the minimum area of the LID facility compared to the target area may be 1 to 5%.

The step of analyzing the properties and concentrations of nonpoint pollutants ( S200 ) is a step of analyzing the properties and concentrations of nonpoint pollutants by analyzing nonpoint pollutants in rainwater collected from the target area.

Here, the properties of the non-point pollutants may vary depending on the type. Nonpoint pollutants include particulate matter (soil, etc.), organic matter, nutrients (N, P, etc.), heavy metals (As, Cd, Cr, Cu, Pb, Zn, etc.), oil (Oil & Grease), microorganisms ( Escherichia coli, etc.), but is not limited thereto.

Since the concentration of nonpoint pollutants is different for each time period and rainfall amount, it can be calculated according to the event mean concentration (EMC).

The flow weighted average concentration (EMC) may be calculated according to the following equation.

The runoff of non-point pollutants generated during rainfall has real-time changes in runoff amount and concentration, and since sampling is not performed at regular intervals for monitoring points, the average concentration based on the arithmetic mean is not representative. Since it is not possible to calculate the representative average concentration of nonpoint pollutants discharged during rainfall with an arithmetic average through monitoring according to regional characteristics, for this reason, nonpoint pollution using a probabilistic statistical method is used. It is desirable to calculate the flow-weighted average concentration taking into account the concentration of the substance and the rate of runoff.

EMC can be calculated by dividing the total amount of accumulated nonpoint pollutants discharged during the rainfall duration T hours from the monitoring area by the total accumulated runoff. EMC can be calculated as the following equation.

Here, C(t) and Q(t) mean the concentration and runoff rate of pollutants for the rainfall duration t, and T represents the total runoff time.

In this step, based on the properties and concentrations of nonpoint pollutants analyzed in the target area, the types of pollutants to be managed can be selected and the concentration range can be limited.

The step of determining the reduction mechanism ( S300 ) is a step of determining the reduction mechanism for reducing the analyzed non-point pollutants.

Reduction mechanism may be divided into physical mechanism (Physical reaction), chemical mechanism (Chemical reaction), biological mechanism (Biological reaction) and the like.

Physical mechanisms include dilution, sedimentation, re-suspension, coagulation, filtration, adsorption, volatilization, evaporation, dissolution , heat transfer, dispersion, etc. may be applicable.

Chemical mechanisms may include photolysis, hydrolysis, precipitation, ionization, oxidation, and reduction.

Biological mechanisms may include bio-degradation, bio-accumulation, and photosynthesis.

The determination of the reduction mechanism can be determined according to the nature, type, and concentration of nonpoint pollutants.

For example, when particulate matter is included in the nonpoint pollutant, the reduction mechanism may be determined as at least one of precipitation, filtration, and adsorption as a physical mechanism. In addition, when heavy metals are included in the nonpoint pollutants, the reduction mechanism may be determined by at least one of adsorption and ion exchange. In addition, when at least one of organic matter, oil, and nutrients is included in the nonpoint pollutant, the reduction mechanism may be determined by decomposition (biological mechanism) through microorganisms and plants.

The step (S400) of determining the detailed conditions for at least one of the soil, filter media, plants, and microorganisms of the LID facility is for at least one of the soil, filter media, plants, and microorganisms of the LID facility for implementing the determined reduction mechanism. This is the stage in which the detailed conditions are determined.

For example, when the reduction mechanism of sedimentation, filtration, and adsorption is determined, soil and filter media may be determined to be inorganic. In addition, when the reduction mechanism of biodegradation is determined, in relation to soil and microorganisms, it may be determined as a condition for the microorganism to respiration, nitrification-denitrification reaction. When the reduction mechanism is determined by photosynthesis, the specific species of the plant can be determined.

Specifically, in the case of soil, the nutrient supply of the vegetation soil in the soil, the pores of the vegetation soil, and the moisture content of the vegetation soil may be determined.

Nutrient supply is the amount of nutrients contained in vegetation soil, and can be a major factor when plants are included in LID facilities. Regarding the pores of the vegetation soil, macropores (0.3~0.5) are required for the storage and penetration of rainwater, and micropores may be required for the removal of pollutants and the activities of microorganisms and plants. The water content can be determined as 20 to 60% for the activity of microorganisms and plants. In addition, the optimum conditions for the temperature (25 to 40 ℃) or pH (4.5 to 8.0) of the vegetation soil can be determined.

In addition, in order to remove particulate matter (particles of 200 μm or larger), it may be decided to install a small settling pond and install an energy attenuation hole for dissipating potential energy.

In the case of the filter material, the depth, length, organic and inorganic properties of the filter material may be determined. Details of the filter medium may be determined as described above with reference to FIG. 2 .

In the case of microorganisms, other microorganisms may be selected according to the properties of nonpoint pollutants.

Plants were determined to have high pollutant reduction efficiency, strong salt resistance, adaptable to extreme climates (drought and flood), and do not require fertilization, but were selected according to the size of the LID facility and the characteristics of non-point pollutants. can do. Plants can be planted in combination rather than a single species to enhance their functions and consider the landscape.

Examples of specific plant selection are shown in [Table 1] below.

classification food life growth rate effort
(cm) growth environment pollutant
Reduction Efficiency LID application
Possibility dry-resistance tolerability sound resistance cold resistance moisture resistance flame resistance wood Metasequoia (Metasequoiaglyptostroboides) fast 200-250 ○ ○ ○ tree filtration
Box Yeongsanhong
(Rhododendron indicum) Slow 15-90 ○ ○ ○ rain garden
Vegetation Residency shrub Meadow
(Spiraeaprunifolia var. simpliciflora) fast 150-200 ○ ○ rain garden
Vegetation Residency Namcheon
(Nandina domestica) Medium 100-300 ○ ○ ○ rain garden
Vegetation Residency conduct fist
(Taxus cuspidata S. et Z.) Medium 1700 ○ ○ Vegetation Residency
wooden filter box camellia
(Camellia japonica L.) Medium 1000 ○ ○ ○ Vegetation Residency
wooden filter box herbal calamus
(Acorus calamus) fast 60
-120 ○ ○ artificial wetland sky hawk claw
(Aquilegia flabellata var. pumila) fast 15-30 ○ ○ rain garden
Vegetation Residency water fight
(Potentilla fruticosa) Medium 15-30 ○ ○ ○ ○ rain garden
Vegetation Residency Michaelmas daisy
(Aster tataricus) Medium 50-60 ○ ○ ○ TSS: 93-94%
Total Zn: 93~97%
Total Pb: 100%
Total Cu: 89~100%
Total Cd: 100% rain garden
Vegetation Residency dianthus
(Dianthus chinensis L.) Medium 10-20 ○ ○ rain garden
Vegetation Residency
roof greening dianthus
(Dianthus c hinensis L.) Medium 10-20 ○ ○ rain garden
Vegetation Residency
roof greening marigold
(Tagetes erecta L.) Medium 25-30 ○ ○ rain garden
Vegetation Residency
roof greening Maekmun-dong
(Liriope platyphlla) Medium 30-50 ○ ○ rain garden
Vegetation Residency

In addition, when the analyzed nonpoint pollutants contain a large amount of salt (eg, when the salt component is strong due to snow removal in winter), it can be determined as a tree species resistant to salt.

An example of plant selection according to salinity is shown in [Table 2] below.

division main species in salinity
strong
dropsy Chohwa: Bermuda Glass, Ground pine, Gaetbangpung, Gingerbread, Golddamcho, Mogamju, etc.
Shrubs: rhododendrons, spruce, oleander, oleifera, fern, money tree, barberry, chick flower, red crimson flower, oleander, oleander, etc.
Trees: camellia, pine, camphor, spruce, spruce, sagebrush, bramble, champignon, brown oak, persimmon, gully, quince, quince, ash, magnolia, himalayashida, rigida pine, sea pine, cypress tree , juniper, juniper, sycamore, lily-of-the-valley, fern, boxwood, brier, tamarisk, etc. in salinity
weak
dropsy Cedar, German spruce, pine, larch, Himalayan cedar, magnolia, bramble, alder, Japanese magnolia, Chinese maple, blooming tree, Yoshino cherry tree, metasequoia, seven-leaved tree, zelkova, wild cherry, etc.

You can also decide to use plants to form a fence (eco-fence).

On the other hand, the specific type and specific structure of the LID facility may also be determined based on the selected detailed conditions. That is, it may be determined which LID facility is to be established, and a specific structure for the facility may be determined. For example, a fresh water depth of 20 to 30 cm can be secured at the upper part of the LID facility, and in the case of an LID facility requiring a top cover, a cover made of a lightweight material can be installed.

The step of determining whether to replace the lower soil ( S500 ) is a step of determining whether to replace the lower soil by determining whether the lower soil of the target area is suitable for the LID facility. Here, the lower soil can be understood as the ground of the location where the LID facility is established.

The type of soil can be divided into 4 types (Type A~D) according to the ratio of sandy soil, loam, and clay. Soil with a high ratio of sandy soil corresponds to Type A, and soil with a high clay ratio corresponds to Type D. Soil with a high ratio of loam to clay can be classified into Type B, and soil with a high ratio of rom can be classified into Type C. The characteristics of each type of soil are shown in [Table 3] below.

Soil Type Soil Characteristics Infiltration Rate
(mm/h) LID facility Type A Least outflow, highest permeability
Sand and gravel layer containing a little silt and clay 7.62-11.43 penetration trench
seepage reservoir
penetrating pots Type B Relatively low outflow rate, relatively high permeability
Drainage is generally good because of sandy soil mixed with gravel 3.61-7.62 Vegetation Residency
rain garden
vegetative water
wooden filter box Type C Relatively high outflow rate, relatively low permeability
Contains a lot of clay and colloidal material 1.27-3.81 Vegetation Residency
rain garden
vegetative water
wooden filter box Type D Highest outflow, lowest permeability
Most are made of clay which makes the drainage poor 0-1.27 artificial wetland
pond
underground storage tank

If the infiltration facility is to be installed on soil Type B, C, or D, the underlying soil may be determined to be replaced with Type A. In particular, as an LID facility that does not include plants, when the underlying soil is Type B, C, or D, it may be determined that the underlying soil is replaced with Type A.

As a LID facility comprising plants, where the underlying soil is Type A, it may be determined that the underlying soil is replaced with Type B, C and/or D.

On the other hand, as a LID facility including plants, when the lower soil is Type A, the lower soil is not replaced, but a separate rainwater runoff blocking facility is provided to secure the moisture content of the soil, or a plurality of LID facilities are connected. can be decided.

The step of drawing the target area where the LID facility is established (S600) is a step of drawing the LID facility establishment in the target area by reflecting the finally determined LID facility and its details.

LID facilities can be established in various ways in connection with buildings, roads, parking lots, intersections, and parks and green areas. In this step, the layout drawing where the LID facility is established can be drawn up. 2 shows an example of a layout diagram. In particular, one applied to a building, one applied to a road, one applied to a parking lot, and one applied to an intersection are respectively shown.

At this stage, LID facilities may be determined to be linked singly or in plurality. In particular, if it is designed to be linked, the effect of reducing rainfall runoff and reducing nonpoint pollutants can be maximized.

If the LID facility is designed alone, allow rainwater to move to the plant side after infiltration. can be designed

In this step, it is decided whether to establish the LID facility alone or in conjunction with multiple establishments, and the decision can be reflected and drawn up.

The protection scope 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 protection scope of the present invention cannot be limited due to obvious changes or substitutions in the technical field to which the present invention pertains.

10: rainwater inlet pipe
20: plant
30: drain pipe
40: rainwater pipe
100: LID facility
110: first floor
120: second floor
S: Vegetation soil

Claims (6)

disposing a first layer comprising organic media within the LID facility; and
disposing a second layer comprising an inorganic filter medium on the first layer;
How to install media in a LID facility. The method of claim 1,
The second layer is characterized in that it is buried at a depth of 50 cm or more from the ground,
How to install media in a LID facility. According to claim 1,
The length of the first layer in a direction parallel to the ground is 1 m or more,
How to install media in a LID facility. The method of claim 1,
disposing a gravel layer inside the LID facility; and
Further comprising the step of disposing vegetation soil on the gravel layer,
The first layer is characterized in that it is disposed on the vegetation soil,
How to install media in a LID facility. 5. The method of claim 4,
disposing an additional gravel layer on the second layer; and
further comprising disposing a woodchip layer on the additional gravel layer;
How to install media in a LID facility. The method of claim 1,
characterized in that the pores of the second layer are larger than the pores of the first layer,
How to install media in a LID facility.

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