KR100616094B1 - The filtering material of disposing nitrogen oxides in atmosphere - Google Patents

Abstract

The present invention relates to a medium for forming a soil layer for treating nitrogen oxides in the air, and more particularly, in order to quickly and largely clean polluted air such as roads, underground parking lots, tunnels, and the like, to prevent drift and closure. It is manufactured by mixing various soils other than general soil in a specific mixing ratio for prevention and moisture retention. In the media layer, nitrogen oxides are produced by physical absorption, adsorption, chemical reaction by the media layer, and aerobic and anaerobic decomposition by microorganisms. Is reduced to the most nitrogen in the general atmosphere or consumed in the metabolism of plants planted on the surface of microorganisms or media layers.

Nitrogen oxide treatment media according to the present invention, the artificial media and make a large amount of microorganisms, and the adsorption of air pollutants to create a pore securing and uniform pore size while making the density, physical stability, soil layer support Organic filter medium to remove air pollutants caused by and microorganisms, and inorganic filter medium to provide a microbial habitat, supply carbon sources and supply nutrients to the microorganism.

Nitrogen oxides, media, soil layers, organic media, inorganic media

Description

The filtering material of disposing nitrogen oxides in atmosphere

      1 (a) (b) (c) (d) is an explanatory diagram of a nitrogen oxide treatment system in a general tunnel atmosphere

2 is a schematic diagram illustrating a conventional nitrogen oxide treatment system.

Figure 3 is a schematic diagram for explaining another conventional nitrogen oxide treatment system

4 is an explanatory diagram of a mechanism for purifying nitrogen oxides by soil

5 is a diagram showing a large circulation of nitrogen oxides according to the present invention by a nitrogen oxide treatment facility;

6 is a schematic diagram of a system for treating nitrogen oxides in the atmosphere according to an exemplary embodiment of the present invention.

Figure 7 is a reference diagram for explaining the kind and role of the media according to the present invention

8 is a bar graph showing the pH and ion exchange capacity of each filter according to the present invention

9 is a change diagram of nitrogen oxide removal efficiency by the filter media layer according to the present invention

10 is a change diagram of nitrogen oxide removal efficiency by the fecal soil mixture media according to the present invention

11 is a change diagram of nitrogen oxide removal efficiency by volcanic ash mixed media according to the present invention

12 is a change diagram of nitrogen oxide removal efficiency by the temperature change of the soil filter medium according to the present invention

13 is a diagram showing the change in nitrogen oxide removal efficiency due to the temperature change of the fecal soil mixture media according to the present invention

14 is a diagram showing the change in nitrogen oxide removal efficiency due to the temperature change of the ash mixture medium according to the present invention

<Explanation of symbols for the main parts of the drawings>

100: artificial filter material 200: inorganic material

300: organic media

The present invention relates to a medium for forming a soil layer for treating nitrogen oxides in the air, and more particularly, in order to quickly and largely clean polluted air such as roads, underground parking lots, tunnels, and the like, to prevent drift and closure. It is manufactured by mixing various soils in a specific mixing ratio to prevent and maintain moisture. In the media layer, nitrogen oxides are produced by physical absorption, adsorption, chemical reaction by the media layer, and aerobic and anaerobic decomposition by microorganisms. To reduce to the most nitrogen in the general atmosphere or to be consumed in the metabolism of plants planted on the surface of microorganisms or media layers.

Nitrogen oxides in the atmosphere are mainly produced from burning fossil fuels. Nitrogen oxides are produced in small amounts in the combustion process, but nitric oxide and nitrogen oxide, which are the major constituents of nitrogen oxides, are generated. In particular, nitrogen dioxide is a harmful substance that can seriously affect the human body.

Nitrogen dioxide destroys the environment. Moisture in the atmosphere, nitrogen monoxide and nitrogen dioxide react to form nitrous acid. That is, it is the main cause of acid rain formation. In addition, it reacts with volatile organic compounds and the like in the atmosphere and is converted into photochemical smog substances such as ozone to cause various respiratory diseases and greatly weaken visibility.

During fuel combustion, nitrogen and oxygen react with each other to form nitrogen oxides. There are two main mechanisms. In the case of fuel nitrogen oxides, fuel is generated by combustion, and thermal nitrogen oxide is a form in which nitrogen molecules in combustion air are reacted at high temperature to form nitrogen oxides. Although the nitrogen oxide gas can be controlled by the temperature of the combustion chamber or the short residence time, the concentration of nitrogen oxide in the air continues to increase due to the increase of the vehicle exhaust gas.

The nitrogen oxide treatment system in tunnels known to date is to vent air containing large amounts of nitrogen oxides out of the tunnel using ventilation. Tunnel ventilation system is divided into natural ventilation system by natural wind and piston effect of automobile, and mechanical ventilation system by mechanical equipment.

Natural ventilation is possible in tunnels with short tunnels and low traffic, but mechanical ventilation is essential for long tunnels. Mechanical ventilation methods are classified into the basic ventilation methods such as type ventilation method, cross-flow ventilation method, and semi-crossflow ventilation method according to the air flow in the roadway, and the combined ventilation method by the combination thereof. In addition, the ventilation method is different depending on the traffic tunnel and the one-way traffic tunnel. In one direction, the automobile piston effect is used for the ventilation ventilation of the tunnel, but not in the case of the facing traffic tunnel. In the case of facing traffic tunnel, as shown in FIG. 1 (a), a jet fan for ventilating by installing a jet fan in a tunnel in one direction by a type ventilation system is applied. Recently, due to the development of excavation technology, the tunnel is constructed in the form of long road tunnel, so it is difficult to maintain the pollution concentration below the standard value in the entire tunnel by the jet fan method.

In addition, as shown in FIG. 1 (b), at least one vertical shaft is installed at the mid-point of the tunnel, or as shown in (c) (d) of FIG. It is divided into a ventilation section of a suitable length that can be ventilated, and a vertical gang supply and exhaust ventilation method is applied to exchange contaminated air and fresh air at an air supply and exhaust point.

However, ventilation does not treat nitrogen oxides but only outflows, which can cause serious environmental pollution at outlets such as tunnel exits.

The treatment of air containing nitrogen oxides includes combustion, drug washing, adsorption, and biological deodorization. Among these methods, biodeodorization is a facility that removes harmful substances in the gas passing through the filling by using microorganisms growing in the reactor by filling soil, compost, activated carbon, peat, etc. in a constant reactor and maintaining proper moisture. . These materials should use particles of equal size to maintain proper voids. In addition, if the particle size is too small, the pressure drop is large, and in this case, the treatment efficiency is greatly lowered due to the short circuit phenomenon. The height of the biofiltration layer is generally about 1m. Polluted off-gas is discharged from the source by passing through a filter bed. During sufficient residence time the contaminants diffuse into the biolayer around the filter. Aerobic decomposition of the substance to be treated takes place in the presence of a microbial layer. The contaminants, when completely degraded by microorganisms, eventually form carbon dioxide and water.

Compost, wood chips, bark, and fallen leaves are commonly used filter materials in Europe, and peat is also used. Most biofilters made in the United States use biologically active mineral soils as filter material. Necessary facilities for the pretreatment of polluted air are transport facilities to filters and distribution facilities. In some cases, a heat exchanger may be used to cool the hot contaminated air or a filter may be used to remove particulate matter, and a brower may be used to compensate for the pressure drop in the filter. Contaminated air must be saturated with water. This is because the contaminated air removes moisture from the filling material and when the filling material is dried, the microorganisms are killed and efficient operation is not performed. Spray nozzles are also used to hydrate. It is also possible to automatically spray moisture on the filter to maintain the required moisture content in the filter material.

When contaminated air is brought into contact with soil, pollutants such as carbon monoxide and nitrogen oxide contained in the polluted gas are adsorbed or dissolved by the soil surface or soil water, and are purified by absorption and decomposition by metabolism of various microorganisms.

An example of air purification technology using soil will be described with reference to FIG. 2.

2 is a schematic diagram of a soil air purification system for purifying the internal air of the underground parking lot 10, the main part of which is provided with a blowing means 11, a gravel crushed layer 12, a soil layer 13, and a planting part 14. It consists of). And the soil layer 13 was used by mixing pearlite, peat moss, pit and the like in the soil.

In the air purification system configured as described above, the contaminated air in the underground runner window 10 is transferred to the reverse layer vent by the blowing means 11 such as a brower, and then, through the soil layer 13 and the planting part 14 thereon. In the process, the polluted air is purified by the physicochemical and biological functions of the soil.

The air purification method using the soil is different from the method using the physical adsorption function such as activated carbon method, but due to the high density of the soil, the processing capacity of polluted air per unit area is reduced, and the construction cost is high because the whole soil is improved. The planted trees were directly affected by the polluted air and had problems.

3 is related to the 'air purification system using soil' introduced in the Korean Patent Publication No. 1999-0046906, the structure is a duct for transporting the broth and the sucked contaminated air to suck the contaminated air in the underground runner window (10) Inlet means 20 consisting of, the gravel crushed stone layer 21 to spread the horizontally contaminated air supplied from the inlet means 20, and sequentially placed in the upper layer of the gravel crushed stone layer 21 in the polluted air Porous layer and soil layer (22) and (23) for purifying contaminants of the soil, and several pipe-type filter tube (24) buried vertically from the top of the soil layer (23) to the lower gravel crushed layer (21) It is a structure.

However, there is currently insufficient soil material for removing nitrogen oxides in tunnels, roadsides, or atmospheric environments. Basically, adsorption deodorization and biological treatment are applied simultaneously. Adsorption deodorization method is a method of removing and deodorizing air pollutants by using the phenomenon that exhaust gas is collected on the surface of adsorbent when solid gas adsorbents such as exhaust gas and activated carbon are in contact with each other. It is applied to low concentration gas treatment. It is applicable to many odorous components such as hydrocarbons, and activated carbon is commonly used as an adsorbent. In the adsorption deodorization method, the adsorption amount of the malodorous component is greatly influenced by the exhaust gas temperature. It is also not suitable for juicy exhaust gases. The adsorbent is saturated when adsorbed more than a certain amount of malodorous components, so the adsorbent must be replaced or regenerated by a recovery device.

In the case of the exchange type in which the adsorbent is exchanged as it is, the apparatus cost is relatively low, but the maintenance cost is relatively high because the exchange adsorbent is expensive. However, the device has the advantage of being simple and easy to manage. The adsorbent is a solid with a large surface area. The odorous substance is removed by adsorption on the surface by intermolecular attraction or electrostatic force. Therefore, the larger the surface area of the adsorbent, the greater the adsorption capacity. Silica gel, alumina, zeolite, etc. are used as adsorbents, but generally, the most commonly used adsorbent for removing air pollutants is carbon. Carbon is made from different carbonaceous raw materials, such as various wood, coal or coconut husks. Three forms of carbon adsorbent are commonly used: granular activated carbon, powdered activated carbon, and carbon fiber. Activity here refers to the removal of volatile non-carbon materials by heating the raw materials at high temperatures to increase the surface area that can be used for adsorption. Particulate activated carbon is most commonly used because of its large surface area and easy regeneration. Although powdered activated carbon is inferior in quality to granular activated carbon, it has a disadvantage in that it must be disposed of after use because the pressure drop is large and the regeneration is impossible. Activated carbon is affected by the temperature, the adsorption amount decreases as the temperature rises, the adsorption amount increases as the concentration of the adsorbent increases, and the boiling gas has a high tendency to adsorb harmful gases.

Although such activated carbon is heatable, incombustible hydrophobic zeolites have recently been used to increase stability due to complexing. Hydrophobic zeolites are high silica with crystal pores that reduce the hygroscopicity of the zeolite and allow it to adsorb odorous substances. Disadvantages of zeolite adsorbents include low adsorption capacity, high regeneration temperature of about 190 ° C. compared to activated carbon (100-140 ° C.), and the removal of odorous substances that are desorbed, which are difficult to reuse for recovery. The field of application of zeolite is mainly used for separation of normal paraffin, dehumidification of air, dehydration of liquid, deodorization of manure treatment plant, carrier of microorganism deodorization method and the like. Other adsorbents used include silica gel, alumina, activated clay, and sulfonated coal.

Biological treatment uses microbial decomposition of pollutants such as nitrogen oxides in the atmosphere. Biological treatments are likewise suitable for low concentration high flow gases. Contaminants are absorbed into the biofilm of the carrier and the microbes attack and decompose the absorbed contaminants in principle.

The purification of air pollutants by media can be divided into two mechanisms. First, there are physical and chemical mechanisms such as adsorption of air pollutants in the media and biological purification mechanisms by microbial metabolism in the soil.

Adsorption by medial particles is a case where the medial particles have the adsorption capacity, the adsorption capacity of organic matter, and are dissolved in water in the media and used for plants and microorganisms. Purification by microorganisms is caused by the type and number of microorganisms present in the media, and generally microorganisms in the media have sufficient types and numbers to purify the air pollutants. Figure 4 shows the principle of purification of nitrogen oxides among the major air pollutants.

Nitrogen oxides are converted to the form of nitrate nitrogen by physicochemical processes that are adsorbed and dissolved by the media particles and the water in the media, or by nitrification bacteria, which are microorganisms present in the media. These nitrate nitrogen is absorbed and used in the metabolism of soil microorganisms and plants. It is also reduced to nitrogen and released into the atmosphere by aerobic degreased microorganisms present in the media. Microorganisms acting on this mechanism are generally present in the media. Since the amount of microorganisms in the media layer is sufficient, no microbial inoculation or other manipulation is required.

As such, basic principles and mechanisms for simultaneously applying adsorption deodorization and biological treatment are known. However, no suitable soil media for the removal of nitrogen oxides from tunnels, roadsides, or atmospheric environments has been proposed. There was a problem that can not.

Accordingly, an object of the present invention is to provide a medium for treating nitrogen oxides in the atmosphere for treating nitrogen oxides in the atmosphere quickly and in large quantities efficiently.

Another object of the present invention is to mix different soils in a specific mixing ratio in order to prevent drift, prevent closure and maintain moisture, so that physical absorption, adsorption, chemical reaction, By aerobic and anaerobic digestion by means of reducing the nitrogen oxides to the most nitrogen in the general atmosphere or to provide a medium for forming a soil layer to be consumed in the metabolism of plants planted on the surface of microorganisms or media layers.

In order to achieve the above object, the medium for treating nitrogen oxides in the air of the present invention includes a soil layer, an adsorbent for collecting exhaust gas in the soil layer, and a microorganism medium for decomposing air pollutants into the microorganisms in the soil layer. In the atmosphere for treating nitrogen oxides in the atmosphere,

An artificial media that makes density, physical stability, and soil layer support possible while making voids and uniform pore size of the nitrogen oxide treatment media within the soil layer;

An organic filter medium having a large amount of microorganisms in the soil layer to remove air pollutants and adsorption of air pollutants;

It provides a microbial habitat in the soil layer, characterized in that it comprises an inorganic medium for supplying a carbon source and supplying nutrients for microorganisms.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

5 shows a large cycle of nitrogen oxides according to the present invention by a nitrogen oxide treatment facility. 6 is a system diagram for treating nitrogen oxides in the air according to an embodiment of the present invention. 7 is a reference diagram for schematically illustrating the type and role of the media according to the present invention. 8 is a bar graph showing the pH and ion exchange capacity of each filter according to the present invention. 9 is a change diagram of nitrogen oxide removal efficiency by the filter media layer according to the present invention. 10 is a change diagram of nitrogen oxide removal efficiency by the fecal soil mixture media according to the present invention. 11 is a change diagram of nitrogen oxide removal efficiency by the volcanic ash mixed media according to the present invention. 12 is a diagram showing a change in nitrogen oxide removal efficiency due to temperature change of the soil filter medium according to the present invention. 13 is a diagram showing the change in nitrogen oxide removal efficiency caused by the temperature change of the fecal soil mixture media according to the present invention. 14 is a diagram showing a change in nitrogen oxide removal efficiency caused by temperature change of the ash mixture medium according to the present invention.

In the purification system to which the present invention is applied, as illustrated in FIG. 6, a duct 30 for transporting nitrogen oxide contaminated air in the atmosphere and a blower 31 are mounted on the flow path of the duct 30 so that the contaminated air is predetermined. It can be configured as a nitrogen oxide treatment system in the air to be transported to the path and finally passed through the filter bed layer 32 to purify the polluted air. Suction duct 30 configured to direct the oxide discharge source, nitrogen oxide constituting the components of the nitrogen oxide sucked from the suction duct 30 and nitrogen oxides to accelerate the reaction of nitrogen monoxide in the slow reaction rate of nitrogen dioxide Ozone oxidation unit 33 installed on the flow path of the suction duct 30 to oxidize nitrogen monoxide among the components, the pollution through the ozone oxidation Spray device installed in the suction duct 30 to increase the moisture content of the suction air before the air is transferred to the filter medium layer 32, the suction air through which the moisture content is adjusted while passing through the spray device the filter layer ( It may be configured by installing a distribution panel 35 for evenly distributing to 32 and the vent pipe 36 in communication with the duct (30).

Here, reference numeral, 37 is a nitrogen oxide automatic measuring device, 41 is a vent, 42 is a pearlite layer for distribution, 50 is a water supply system.

In the method for treating nitrogen oxide in the air by the device, the step of sucking the nitrogen oxide contaminated air in the air through the suction duct 30, nitrogen monoxide and nitrogen dioxide constituting the components of the nitrogen oxide sucked from the suction duct 30. Oxidation step of oxidizing nitrogen monoxide out of constituents of nitrogen oxide to nitrogen dioxide in order to promote the reaction of nitrogen monoxide having a slow reaction rate, and the moisture content of intake air before transferring the oxidized contaminated air to the media layer 32 The nitrogen oxide in the air is treated in a distribution control step of controlling the moisture through the spraying device 34 and distributing the intake air whose moisture content is controlled through the distribution panel 35 through the distribution panel 35.

When ozone is supplied in order to oxidize nitrogen monoxide to nitrogen dioxide in the oxidation step, it is possible to easily oxidize nitrogen monoxide in the nitrogen oxide constituents and convert it into nitrogen dioxide having a fast reaction rate, thereby enabling rapid and reliable purification.

The media according to the present invention applicable to the purification system, as shown in Figure 7, artificial media made of activated carbon or pearlite to make the density and physical stability, soil layer support while making pore size and uniform pore size of the media layer (100), the inorganic filter medium (200) to provide a microbial habitat space, supply a carbon source and supply nutrients for microorganisms, and to retain a large amount of microorganisms to remove air pollutants and remove air pollutants by microorganisms It can be configured to include an organic filter (300).

The inorganic filter 200 may be a volcanic ash, briquette, ash, fecal soil, etc. to remove air pollutants using microorganisms after the microorganisms are inoculated from the organic filter 300, similar to the organic filter 300. .

The organic filter 300 may be used to supply essential nutrients necessary for the activation of microorganisms, and can be used to remove the air pollutants by adsorption and microorganisms, such as compost, flounder.

The filter medium according to the present invention is manufactured by calculating the optimal configuration, mixing and blending ratios by dividing into the organic filter 300, the inorganic filter 200, and the artificial filter 100, respectively.

Figure 5 shows a large circulation of nitrogen oxides by the nitrogen oxide treatment equipment, the nitrogen oxide of the air pollutants generated from the exhaust gas is more than 90% is released in the form of NO. NO is a stable substance, which reacts slowly in the air and is a harmful air pollutant. In order to remove such NO, a process of artificially oxidizing to NO2 using ozone is required. The pollutants oxidized to NO2 enter the media layer, and some of them are adsorbed by the media particles, and the rest are converted to the form of NO3_ which is dissolved in water or available for metabolism of plants or microorganisms by microorganisms. Nitrogen oxides in the form of NO3_ are used by plants for absorption or metabolism of microorganisms. Pollutants in the form of nitrogen oxides emitted from automobiles through this large cycle of nitrogen pass through ozone oxidation and the media and are adsorbed on media or used for microorganisms and plants.

Carbon monoxide, another air pollutant, is released as carbon dioxide by metabolism of microorganisms in the media. Suspended particulate matter is adsorbed into the media by the filtering effect of the media. In addition, harmful air pollutants such as benzene and toluene are also purified by adsorption and microbial decomposition by media.

Figure 7 is a reference diagram for explaining the type and role of the filter medium, the filter medium is largely divided into organic filter 300, inorganic filter 200 and artificial filter (100). The organic filter 300 is soil, compost, and foliar soil, and secures a large amount of microorganisms. The organic filter 300 supplies various microorganisms necessary for growth and removes air pollutants by adsorption and microbial use. The inorganic filter 200 may selectively use volcanic ash, briquettes, ash, feces, etc., and serves to provide a space and a carbon source for growing microorganisms, and after the microorganisms are inoculated from the organic filter 300, the organic filter Like ash, it plays a role in removing air pollutants such as the use of microorganisms. Artificial filter 100 is made of activated carbon, pearlite, etc. to ensure the pore of the filter media layer and uniform pore size, and to enable the density, physical stability, bearing capacity and the like. Composing and mixing these media in combination can provide the optimal media layer to remove air pollutants.

The optimal media layer should have excellent ability to remove air pollutants per area, be chemically stable, and ensure pH buffering capacity, clean drainage, permanent use, and economics.

Treatment of air pollutants with soil may be toxic due to the chemical nature of the gas, ie the presence or high concentrations of gas components that are toxic to microorganisms, so all types and quantitative characteristics of the gas components should be investigated before design. If the load of particulate matter is high, it may adversely affect the operation of the facility, such as mixing phenomenon in the air dispersing facility or the soil layer itself.

It is also important to maintain the moisture content in the soil layer in the optimum range in the exhaust gas treatment. In general, raw gas is introduced in a state where the water is not saturated, so the soil layer dries quickly and additional water is required. Moisture is essential for the survival and metabolism of microorganisms and creates the buffer capacity of the filter. Non-optimal moisture content can lead to compacting of the filler material, leakage of untreated gas and formation of anaerobic zones that release odors. In general, a water content of 40 to 60% by mass is considered to be appropriate.

Most raw gases entering the soil layer have a saturation of 95% or more. Excessive moisture from the soil layers can lead to wastewater. In general, water drained from soluble compost contains thousands of mg / L of high BOD, and biologically poorly decomposed material that has been washed away from the soil layer, and when acidic degradation products are formed, the drained water has low pH. Have.

Since most microorganisms like a specific pH range, changing the pH of a filler affects the activity of the microorganism. Typical pH in soil layers containing compost is between 7 and 8, with high activity of bacterial actinomycetes in this range.

Acid by-products may be produced during the biodegradation of sulfur or nitrogen-containing compounds and chlorine-based organic compounds. In addition, depending on the type of microorganisms, there may be a possibility of strengthening the pH, in which case the destruction capacity of the soil layer can be reduced by destroying the microbial population.

In the exhaust gas purification utilizing the filter bed, periodic and continuous maintenance is involved in the operation. Key operating parameters that should be checked daily include exhaust gas temperature, humidity, filter temperature and negative pressure.

Most open exhaust gas purification systems do not automatically adjust the moisture content or filter in the soil layer, and should perform periodic sampling of the soil layer, check the pH change, turn over the soil layer, or replace it after several years. Maintenance required for open systems.

The air pollutant treatment technology using the filter media has different physicochemical conditions and colonies of microorganisms depending on the type of filter media.

In order to know the characteristics of the filter media according to the present invention, the ability to remove nitrogen monoxide was tested by using compost as a main raw material, and the mixed media including coal ash including coal ash, coal ash of thermal power plant, artificial media, etc. Was prepared as follows.

The experimental condition table of the mixed media layer is shown in Table 1.

Compost was used in the defoliated state of deciduous leaves and the like.

Volcanic ash was used as a commodity, and soil layer experiments were conducted on ecologically treated fecal and non-contaminated soil.

The media layer tends to depend on the activity of the mesophilic microorganisms and the dependence on the thermophilic microorganisms is relatively high. On the other hand, the decomposition rate increases with increasing temperature. Another major consideration is that operation at high temperatures can change the microbial population to a high temperature microbial population. In general, in order to maximize the efficiency of the filter media it is desirable to maintain the inlet gas temperature in the range 20 ~ 40 ℃. If the temperature of the inlet gas is too high, cooling will be required. Heat recovery can be economically viable in such cases. If the gas enters the unheated state during the winter, the operating temperature of the filter bed may drop below 10 ° C. In such a case, the removal efficiency may decrease. Accordingly, in order to determine the air pollutant treatment capacity of the media layer according to the temperature, the experiment of the media temperature effect in the thermostat was tested by the condition table as shown in Table 2.

On the other hand, the removal efficiency of nitrogen oxides by the filter media layer was calculated as the removal efficiency of the nitrogen monoxide concentration by subtracting the outflow concentration from the inflow concentration to indicate the removal efficiency in%.

The physicochemical characteristics and nitrogen oxide removal efficiency of the media layer according to the present invention are as follows.

The mixed media used in this experiment were fecal soil, volcanic ash, compost, perlite, soil, fecal soil mixed media with fecal soil and compost, and volcanic ash mixed media with volcanic ash, compost, and pearlite, respectively. Microorganisms are highly affected by pH, generally active in neutral growth and metabolism, and inhibited in acidic and alkaline.

In the mixed media used in this experiment, as shown in Table 3, the lowest ash was measured as 6.2, and the highest values of activated carbon and compost were 9.0 and 8.5, respectively. In case of mixed media, pH 8.4 ~ 8.5 was shown. The pH of the overall media showed that the activated carbon had a weak alkalinity of pH 9.0, while the other media showed a neutral range of pH 6.2-8.5, which did not affect microbial growth. In addition, the index of ion exchange capacity (EC) shows the adsorption and ion exchange capacity of each medium. In the case of EC, activated carbon showed the highest value, and compost and fecal soil showed 13.8 and 1.7mΩ, respectively. Soil showed a similar value of 0.078 mΩ. Table 3 shows the pH and EC values of the media according to the present invention.

Figure 8 shows each value in a bar graph to more clearly know the pH and EC of each medium. In the case of pH, all media shows similar values in the neutral range. On the other hand, in the case of EC, activated carbon and compost showed relatively higher values than other media, and the mixed media filled in the reactor showed higher values.

Changes in Nitrogen Oxide Removal Efficiency of Each Media with Time

In order to find out the change of nitrogen oxide removal efficiency by different media at the time, it was operated for about 20 days using a reactor filled with soil only, a reactor filled with fecal soil mixed media, and a reactor filled with volcanic ash mixed media.

The inlet concentration was operated at 3 ppmNO2, and each reactor was continuously supplied with air to maintain aerobic conditions. The inlet air was supplied by saturating the moisture by 95% or more, preventing the drying phenomenon due to the inflow of air, and preventing the microbial growth from falling as much as possible.

1) Changes in NOx Removal Efficiency Through Soil Media

In the case of the reactor filled with soil only, as shown in the graph showing the change of nitrogen oxide removal efficiency in the filter layer filled with soil only in FIG. 9, the nitrogen oxide removal efficiency was 90% or more for about 4 days during the initial operation, but after 4 days. The removal capacity began to decrease rapidly, and after 15 days, the removal efficiency remained around 46%. This initial high removal efficiency is due to the adsorption capacity of the soil, and the removal efficiency of nitrogen oxides is also reduced due to the decrease in the adsorption capacity of the soil due to the continuous inflow of pollutants. In this case, the soil filling was limited due to the lack of carbon source and other nutrients required for microbial growth. As the adsorption capacity of the soil decreased, the removal efficiency continued to decrease, The removal efficiency of nitrogen oxide was about 46% due to the aerobic denitrification microorganisms and the soil adsorption capacity.

That is, as can be seen in the graph of Figure 9, after about four days, the removal efficiency is sharply reduced, but it can be seen that the trend of reduction in removal efficiency is relaxed around 15 days, and after 15 days, the removal efficiency is about 46%. It could be confirmed that it is kept constant.

2) Changes in NOx Removal Efficiency by Fecal Soil, Compost and Perlite Mixed Media Layers

10 is a graph showing changes in nitrogen oxide removal efficiency due to the fecal soil, compost and perlite mixed media layers. In the case of the fecal mixed media layer, the nitrogen oxide removal efficiency was about 94% when operated up to 4 days. After days the removal efficiency continued to increase.

In addition, after 13 days of operation, the removal efficiency exceeded 97%.

The removal efficiency was maintained at 97.5%. Fecal mixture media, unlike the soil layer, has a large amount of carbon sources, nutrients, and abundant pores required for microbial growth, and the basic initial microbial content is high. Therefore, the removal efficiency of nitrogen oxides by aerobic denitrification microorganisms is higher than that of the soil layer. Experimental results showed that the NOx removal efficiency decreased somewhat until 4 days after the start of operation, but NOx removal efficiency increased continuously after 4 days. This is due to the high adsorption capacity of fecal soil and compost and the improvement of nitrogen oxide removal efficiency due to the denitrification of microorganisms.

3) Changes in NOx Concentrations in Volcanic Ash, Compost, and Perlite Mixed Media Layers

11 is a change diagram of nitrogen oxide removal efficiency by the volcanic ash mixed media layer, the initial nitrogen oxide removal efficiency was about 95% and showed a tendency to decrease until 4 days of operation. After 4 days, the removal efficiency continued to increase, and on the 9th, the removal efficiency increased to 97%. Since then, the removal efficiency has remained almost constant and the removal efficiency has remained somewhat lower than about 97%.

Changes in Nitrogen Oxide Removal Efficiency of Each Media by Temperature

Nitrogen oxide removal system using media is a technology that removes pollutants in the air by using the media's adsorption capacity and microbial denitrification capacity. The growth of microorganisms is an important factor that determines the ability to remove pollutants. The first factor that affects microbial growth is temperature. In general, the activity of the microorganisms is reported to be the best at room temperature (20 ℃), it is known that not significantly affected until 10 ℃. In order to investigate the effect of the temperature on the system removal efficiency through the media according to the present invention, the experimental conditions in which the reactor is installed and the temperature are changed to 10 ° C. and 5 ° C., respectively, and the change in the removal efficiency is shown below. Could get together.

1) Changes in NOx Removal Efficiency of Soil-filled Media Layers

The soil-filled reactor was operated at an initial 5 ° C. for 20 days, and experimented by maintaining the temperature at 10 ° C. under the same conditions. As a result, as shown in the efficiency change diagram of FIG. 12, the removal efficiency is similar to the soil-filled reactor regardless of temperature. In the case of soil layer, the adsorption capacity of the soil can be greatly influenced by the effect of microorganisms when removing nitrogen oxides. The removal efficiency was almost similar for 4 days after operation, and the removal efficiency was reduced compared to the case where the reactor operated at 10 ° C from 4 days to 7 days was operated at 5 ° C, and both reactors showed similar removal efficiency after 7 days. . Both reactors showed nitrogen oxide removal efficiency of about 46% after 14 days.

2) Changes in NOx Removal Efficiency of Fecal Mixed Media Layers

As shown in Figure 13, in the case of the reactor mixed with fecal soil and compost, pearlite showed a slight difference in the removal efficiency as a result of the experiment by changing only the temperature under the same conditions. First of all, in the case of the reactor operated at 5 ° C. for 20 days, the removal efficiency tended to decrease for the first 4 days, but after 4 days, the removal efficiency began to increase again. In addition, after 5 days, the removal efficiency was about 95.5%, and after 14 days of operation, the removal efficiency was about 96.5%.

After 14 days, the NOx removal efficiency was almost unchanged. On the other hand, in the reactor operated at 10 ° C, the removal efficiency decreased to 97% for the first four days, but after that, the removal efficiency increased to show removal efficiency of more than 98%. After 14 days of operation, the nitrogen oxide removal efficiency was about 99%.

These results can be seen that when operating at 10 ℃ compared to the reactor at 5 ℃ more favorable for the growth of microorganisms, it can be seen that the removal efficiency is also very high. In the removal efficiency, the removal efficiency was 96.5% at 5 ° C, and the removal efficiency was about 99% at 10 ° C.

3) Changes in NOx Removal Efficiency of Volcanic Ash Mixed Media Layers

Figure 14 shows the change diagram of nitrogen oxide removal efficiency by temperature in the media layer mixed with volcanic ash, compost, and pearlite. The volcanic ash mixed media showed similar tendency as the experimental results of the fecal mixed media layer. In the case of the volcanic ash mixed media reactor, the removal efficiency decreased after 4 days of operation, and gradually recovered over the period of time. Removal efficiency was shown. As shown in the removal efficiency diagram of FIG. 14, the removal efficiency of both reactors decreased after 4 days of operation regardless of temperature. This means that the removal efficiency of nitrogen oxides decreases as the adsorption capacity of the media decreases before microorganisms adapt. However, after 4 days, the nitrogen oxide removal efficiency was restored, and after about 10 days, the nitrogen oxide removal efficiency was maintained.

As described above, in order to treat nitrogen oxides in exhaust gas using environmentally friendly media according to the present invention, experiments on the removal efficiency of nitrogen oxides and changes in the removal efficiency according to temperature were carried out using mixed media. Got.

In case of pH of each media, activated carbon showed a weak alkalinity of pH 9.0 and the lowest value of volcanic ash at pH 6.2.

The median pH range was 6.2-7.5, with the exception of activated carbon. PH of the mixed media showed a value of pH 8.4 ~ 8.5.

EC values of compost and activated carbon were the highest at 13.8 and 14.5mΩ, respectively, and soil was the lowest at 0.078mΩ. EC of fecal soil, volcanic ash and pearlite showed 1.7, 0.2 and 0.01 mΩ, respectively.

In addition, the soil layer, which was composed of fecal soil, pearlite, and compost, and volcanic, perlite, and compost mixed layers, were operated for 20 days. However, over time, the removal efficiency decreased continuously, and after 15 days, the removal efficiency was about 46%, and remained constant thereafter.

In the case of fecal mixed media, the removal efficiency was about 95%, and the removal efficiency remained unchanged until about 4 days, and the removal efficiency increased continuously after 4 days. After about 16 days of operation, the removal efficiency reached 97.5%, and after that, the removal efficiency continued.

The volcanic ash mixture media showed similar removal efficiency of about 95% at first, and decreased to 94.5% at the first 4 days of operation. After that, the removal efficiency continued to increase, reaching a removal efficiency of 97% at about 18 days, and remained quasi-equilibrium.

In order to examine the effect of temperature on each reactor, all other conditions were kept the same, and the experimental conditions of the reactor were changed to 5 ° C and 10 ° C. Turned out to be. In the case of the fecal mixed media layer, the removal efficiency of the reactor operated at 5 ° C. was about 96.5%, and the reactor operating at 10 ° C. showed high removal efficiency of more than about 99%. The volcanic ash mixture media showed a removal efficiency of 97% at 5 ° C, a removal efficiency of 98.7 at 10 ° C, and an increase in removal efficiency as the temperature increased.

As described above, the filter medium for treating nitrogen oxides in the air according to the present invention can efficiently and efficiently treat nitrogen oxides in the air quickly and in a large number, and is not a general soil for preventing drift, preventing closure, and maintaining moisture. Eggplant soils are mixed at a specific mixing ratio to reduce nitrogen oxides to the most nitrogen in the general atmosphere by physical absorption, adsorption, chemical reactions, and aerobic and anaerobic decomposition by microorganisms. There is an effect that can be consumed in the metabolism of plants planted on the surface of the media layer.

Claims (12)

In the medium for treating nitrogen oxides in the atmosphere consisting of a soil layer, an adsorbent for collecting the exhaust gas in the soil layer, and a microorganism filter medium for decomposing air pollutants into the microorganisms in the soil layer, An artificial mediator that makes voids and uniform pore size of the nitrogen oxide treatment media in the soil layer; An organic filter medium having a large amount of microorganisms in the soil layer to remove air pollutants and adsorption of air pollutants; The filter medium for treating nitrogen oxides in the atmosphere, comprising an inorganic filter medium providing a microbial habitat space in the soil layer, supplying a carbon source, and supplying a nutrient for microorganisms. The method of claim 1, Media for treating nitrogen oxides in the atmosphere, characterized in that using activated carbon as the artificial media. The method of claim 1, Media for treating nitrogen oxides in the atmosphere, characterized in that perlite is used as the artificial media. The method of claim 1, As the inorganic filter, a filter for treating nitrogen oxides in the atmosphere, characterized by using a volcanic ash. The method of claim 1, A filter medium for treating nitrogen oxides in the atmosphere, wherein briquettes are used as the inorganic filter. The method of claim 1, As the inorganic filter, a filter for treating nitrogen oxides in the atmosphere, characterized by using fecal soil. The method of claim 1, As the inorganic filter, a filter for treating nitrogen oxides in the atmosphere, characterized in that coal ash is used. The method of claim 1, The filter medium for treating nitrogen oxides in the atmosphere, which uses soil as the organic filter. The method of claim 1, As the organic filter, the medium for treating nitrogen oxides in the atmosphere, characterized in that the use of compost. The method of claim 1, A filter medium for treating nitrogen oxides in the atmosphere, characterized in that a flounder soil is used as the organic filter. The method of claim 1, The filter medium for treating nitrogen oxides in the air, characterized in that the artificial filter, the organic filter, and the inorganic filter are mixed at a weight ratio of 20 to 40%, 10 to 30%, and 40 to 60%. The method of claim 1, Media for treating nitrogen oxides in the air, characterized in that to maintain the respective media at a temperature of 10 degrees or more.

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