KR101768705B1 - PHOTOCATALYST COATING ZEOLITE SURFACE MEDIA and GREEN INFRASTRUCTURE USING THE SAME - Google Patents
PHOTOCATALYST COATING ZEOLITE SURFACE MEDIA and GREEN INFRASTRUCTURE USING THE SAME Download PDFInfo
- Publication number
- KR101768705B1 KR101768705B1 KR1020160024702A KR20160024702A KR101768705B1 KR 101768705 B1 KR101768705 B1 KR 101768705B1 KR 1020160024702 A KR1020160024702 A KR 1020160024702A KR 20160024702 A KR20160024702 A KR 20160024702A KR 101768705 B1 KR101768705 B1 KR 101768705B1
- Authority
- KR
- South Korea
- Prior art keywords
- photocatalyst
- zeolite
- layer
- green infrastructure
- nanoparticles
- Prior art date
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
- B01J20/10—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
- B01J20/16—Alumino-silicates
- B01J20/18—Synthetic zeolitic molecular sieves
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/54—Nitrogen compounds
- B01D53/56—Nitrogen oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/002—Catalysts characterised by their physical properties
- B01J35/004—Photocatalysts
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/28—Treatment of water, waste water, or sewage by sorption
- C02F1/281—Treatment of water, waste water, or sewage by sorption using inorganic sorbents
-
- E—FIXED CONSTRUCTIONS
- E03—WATER SUPPLY; SEWERAGE
- E03F—SEWERS; CESSPOOLS
- E03F1/00—Methods, systems, or installations for draining-off sewage or storm water
- E03F1/002—Methods, systems, or installations for draining-off sewage or storm water with disposal into the ground, e.g. via dry wells
-
- E—FIXED CONSTRUCTIONS
- E03—WATER SUPPLY; SEWERAGE
- E03F—SEWERS; CESSPOOLS
- E03F5/00—Sewerage structures
- E03F5/10—Collecting-tanks; Equalising-tanks for regulating the run-off; Laying-up basins
- E03F5/101—Dedicated additional structures, interposed or parallel to the sewer system
-
- E—FIXED CONSTRUCTIONS
- E03—WATER SUPPLY; SEWERAGE
- E03F—SEWERS; CESSPOOLS
- E03F5/00—Sewerage structures
- E03F5/14—Devices for separating liquid or solid substances from sewage, e.g. sand or sludge traps, rakes or grates
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2221/00—Applications of separation devices
- B01D2221/12—Separation devices for treating rain or storm water
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
- B01D2253/10—Inorganic adsorbents
- B01D2253/106—Silica or silicates
- B01D2253/108—Zeolites
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/001—Runoff or storm water
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/30—Wastewater or sewage treatment systems using renewable energies
- Y02W10/37—Wastewater or sewage treatment systems using renewable energies using solar energy
Abstract
Description
The present invention can be applied to a surface layer filter of an urban green infrastructure such as a rain garden or a filter strip so as to reduce pollutants in the water, The structure of the media layer of the green infra facility.
The present invention will be described with reference to a lane garden as a representative example of a city green infrastructure facility to which the present invention is applied. However, the technical idea of the present invention is not limited to this and can be applied to various green infrastructure facilities. Which are also within the scope of the present invention. The present invention, on the other hand, is particularly specific to 'natural' urban green infrastructure (eg, rain gardens, flower beds, or filter strips). And to provide differentiated technologies for reducing non-point pollutants and air pollutants under natural light. To do this, we want to identify the photocatalyst, and take measures such as maintenance of the surface layer.
In recent years, the development of low impacts for the recovery of water circulation and reduction of urban environmental pollution through the reduction of non-point pollution and rainfall runoff in urban areas, or the application of urban green infrastructure technology has been increasing day by day.
Typical urban green infrastructure facilities, such as lane gardens, filter strips, grass swales, man-made wetlands, or rooftop greening facilities, remove rainwater runoff and associated pollutants from the impervious surface of urban areas by filtration and penetration, The focus is on recovering the water cycle health of the city. Therefore, in order to utilize the filtration mechanism, various types of artificial soil or filter media are generally used.
It is also known that the urban green infrastructure facility can also absorb pollutants from the soil layer or the media layer through vegetation, and also can purify urban air through photosynthesis of vegetation. However, these green infrastructures mainly focus on the restoration of the water circulation soundness to reduce the surface runoff and the groundwater content by penetrating the rainfall runoff into the soil layer smoothly. The removal of pollutants is a secondary function and the efficiency is also limited .
This development technology relates to the development of a photocatalyst-coated zeolite filter material applicable as a filter medium used in the above-mentioned green infrastructure facility. The present invention reduces the amount of air pollutants such as NOx and VOC by applying ultraviolet-sensitive photocatalyst (TiO2) or visible light-sensitive composite photocatalyst (WO3 / TiO2) on the surface of zeolite and applying it to the surface layer, (Organic matter, heavy metal) can be removed by adsorption, photo-oxidation or ion exchange.
Photocatalyst (photocatalyst) is a substance that promotes photochemical reaction. Typically, the action and effect of titanium oxide are helping to solve environmental problems. However, since the tin oxide is reacted in the ultraviolet region, there is a limit to apply to the natural green city infrastructure of the present invention. That is, the facility or apparatus type can utilize an ultraviolet artificial light source relatively well, but in a facility such as a natural rain garden, an ultraviolet ray region including about 4% of the sunlight should be utilized, It is necessary to secure a wide range. Therefore, the present invention is to provide a nanocomposite photocatalyst which is stable in the filter medium and has excellent catalytic activity even in visible light when a photocatalyst is applied to a natural urban green infrastructure (for example, a rain garden). The present invention provides a method for producing a nanocomposite photocatalyst having such properties. Thereby increasing the solar light source response efficiency.
In addition, the present invention relates to a filter medium structure used in the above-mentioned green infrastructure, wherein a zeolite layer coated with a photocatalyst is provided on the surface layer of the green infrastructure, a sand filter layer coated on the lower layer of the soil for vegetation, The lowest part is the structure of multi-media layer structure composed of gravel layer and its design method. Zero-gaseous nano-iron has generally been proposed for use in the form of permeable reaction walls for soil oil contamination and nitric acid removal.
The depth of the zeolite layer coated with the photocatalyst in the arrangement of the multi-media layer should take into consideration the penetration depth of sunlight (ultraviolet ray, etc.). The penetration depth of sunlight is limited, so that the depth is deepened, and the efficiency of the photocatalyst-coated zeolite layer is not improved. However, if the surface layer is shallow, it is difficult to maintain the zeolite layer coated with the photocatalyst. For this reason, when the surface layer, which should be uniformly installed, is lost due to natural environment such as wind or rainfall and its lower layer is exposed, the effect of the action of the non-point pollutant treatment and air pollutant treatment of the present invention is reduced. The present invention attempts to secure economical efficiency in consideration of the thickness of the surface layer.
As a prior art related to non-point pollution using a photocatalyst, there is an early stormwater effluent purification treatment apparatus of a non-point pollution source of Korean Utility Model No. 20-0426715 registered in the Republic of Korea. The present invention relates to an apparatus for purifying an initial stormwater effluent of a nonpoint pollution source and a method of using the activated carbon treated with a photocatalyst. However, the present invention aims at improving both water quality and air quality, Photocatalytic coating, etc., and a configuration to be applied to the green infrastructure.
In addition, Korean Patent Publication No. 10-1244388 discloses a free water surface type artificial wetland for livestock industry to reduce non-point pollutants. In order to reduce non-point pollutants in livestock farms, a shallow- Type purification stepping bridges and constructed wetlands, and that they include a photocatalyst in a discharge pipe to remove odors. However, the present invention is intended to improve both water quality and air quality, There is a difference in that a method of applying a photocatalytic coating for improving efficiency and a configuration for applying to a green infrastructure are proposed.
Korean Unexamined Patent Application Publication No. 2007-0106126 An early stormwater effluent purging treatment apparatus using a photocatalyst oxidizes contaminants adsorbed on a filter and an activated carbon, thereby significantly extending the useful life of the activated carbon and the filter, The present invention provides a device for purifying initial effluent of a nonpoint source that can easily carry out a maintenance operation. However, the present invention provides a method of improving both water quality and air quality And there is a difference in that it proposes a method such as a photocatalytic coating method for enhancing efficiency and a configuration applied to a green infrastructure.
The object of the present invention is to apply a photocatalyst to a surface of a facility by coating the surface of the zeolite with a photocatalyst so as to be able to effectively control contaminants in the atmosphere and water by applying it to an urban green infrastructure facility, do.
The present invention is characterized in that a zeolite layer coated with the above-described photocatalyst is provided instead of a mulch generally used for the surface of a rain garden, and a sand filter material layer containing zero-valent nano iron is installed below the soil layer of the rain garden (VOCs, Volatile Organic Compounds, Volatile Organic Compounds) such as nitrogen oxides (NOx) in the atmosphere by improving the efficiency of reducing organic matters and heavy metals in rainwater runoffs. The present invention is to provide a technology that can be applied to natural urban green infrastructures such as lane gardens and filter strips.
In order to increase the efficacy of the photocatalyst-coated zeolite layer applied to the surface layer of a natural-type urban green infrastructure such as the lane garden, the present invention can be applied not only in the ultraviolet region but also in a visible light region in a natural state, Thereby providing a photocatalyst that minimizes light scattering.
The present invention discloses a structure in which a filter material including a photocatalyst and a filter material layer including a zero-valent nano iron are combined, and the structure is easy to maintain.
In order to solve the above problems, the present invention provides a green infra that is exposed to an external environment to reduce non-point pollutants, wherein at least two of the at least two media layers are formed, The present invention provides a green infrastructure characterized by being able to treat nitrogen oxides in the air while reducing pollutants.
The surface layer may be a zeolite layer coated with a photocatalyst, and a soil layer capable of vegetation may be formed under the zeolite layer.
The photocatalyst-coated zeolite may include: Preparing a zeolite filter material, placing the zeolite filter material in a crucible, heating the organic material in the furnace to volatilize the organic material present in the zeolite and then cooling the resultant at room temperature, adding distilled water and photocatalyst particles to the crucible containing the zeolite after the calcination step, A mixing step of mixing zeolite and photocatalyst nanoparticles sufficiently mixed by a stir bar or the like, a drying step of placing a crucible containing a mixed solution prepared in the step of mixing the zeolite and the photocatalyst nanoparticles in a dry oven and drying the mixture, And heating the mixture in a furnace to cause the photocatalyst nanoparticles to aggregate at the surface of the zeolite so that the photocatalyst nanoparticles are tightly adhered to each other and solidified. .
In the mixing step of the zeolite and the photocatalyst nanoparticles, 100 g of zeolite and 20 g of photocatalyst particles are mixed per 100 g of the distilled water to prepare a photocatalyst-coated zeolite.
The green infrastructure may be a lane garden, a filter strip, or a flower bed.
Wherein the photocatalyst is a nanocomposite photocatalyst, and the nanocomposite photocatalyst is formed by a method of preparing a nanocomposite photocatalyst of host nanoparticles and guest nanoparticles, comprising: modifying the surface of host nanoparticles with a basic aqueous solution; Mixing an aqueous solution containing the surface-modified host nanoparticles with an aqueous solution containing the guest nanoparticle precursor to form a complex; And a step of drying and calcining the formed complex. The method for producing a nanocomposite photocatalyst according to
The surface layer may be a water-permeable block layer coated with a photocatalyst.
Wherein the photocatalyst-coated water-permeable block comprises: preparing a mixed solution by mixing an aqueous solution of a photocatalyst and an aqueous solution of sodium silicate; Injecting the mixed solution into an air spray gun and spraying the mixed solution onto the surface of the permeable block; And a step of putting the post-injection pervious block in an oven and drying.
And the pressure of the air spray gun is 0.4 MPa.
The permeable block is placed in an oven and dried at 70 ° C. for 12 hours.
In order to solve the above-described problems, the present invention provides a filter medium applied to a green infrastructure for reducing nonpoint pollutants by being exposed to an external environment, wherein the green infrastructure comprises two or more filter media layers, To provide a zeolite whose surface is coated with a photocatalyst so as to treat atmospheric nitrogen oxides as well as to reduce nonpoint pollutants.
The present invention also provides a green infrastructure including a wetland, a lane garden, and a penetration ditch, wherein the roof infrastructure has a photocatalytic surface layered filter media zone, a loop drain is formed outside the barrier plate surrounding the photocatalytic surface layer media zone, And a perforated pipe connected to the outside is buried under the surface layer so that the photocatalytic surface layer filter material is not lost.
According to the present invention, the urban green infrastructure facility, which is focused on the recovery of water circulation in the past, enables effective control of pollutants in the atmosphere and in the water.
When a nanocomposite photocatalyst in which guest nanoparticles effectively absorbing visible light according to the manufacturing method proposed by the present invention is uniformly dispersed in host nanoparticles having a relatively large band gap energy is applied to the zeolite layer, Since the catalyst activity is excellent and the stability is excellent, the efficacy of the natural-type urban green infrastructure of the present invention is excellent, in particular, the daily air pollutant reduction effect without raining.
The present invention has a combination of a filter material including a photocatalyst and a filtering material layer containing zero-valent nano iron, and has an effect of easy maintenance.
1 and 2 show the results of performing nitrogen oxide (NOx) removal experiments in air using the zeolite filter material coated with the photocatalyst nanoparticles of the present invention.
FIG. 3 is a graph showing the results of performing a nitrogen oxide (NOx) removal experiment after coating
4 is a conceptual view of a cross section of a lane garden as an embodiment to which the present invention is applied.
FIG. 5 is a view illustrating a parking lot flower bed as another embodiment of the present invention.
6 to 10 are views showing a composite green infrastructure to which the present invention is applied. 6 is a top view of a composite green infrastructure to which the present invention is applied.
FIGS. 7 and 8 show the first embodiment of the cross section AA 'of FIG. 6, and FIG. 8 is an enlarged view of a part of FIG.
Figs. 9 and 10 show a second embodiment of the AA 'cross section of Fig. 6, and Fig. 10 is an enlarged view of a portion of Fig.
Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not to be construed as limiting the invention to the precise form disclosed. It is provided to let you know.
[Photocatalyst-coated zeolite]
The present invention is characterized in that a zeolite layer coated with a photocatalyst instead of a mulch generally used on the surface of a green infrastructure such as a lane garden is provided and a sand filter media layer coated with zero- It is a technology that improves the efficiency of organic matter and heavy metal reduction in rainfall runoff and treats VOC materials such as nitrogen oxide (NOx) in the atmosphere. It is not only a rain garden, but also a filter strip and a tree box It is a technology applicable to urban green infrastructure.
As a first embodiment of the present invention, the process for producing the photocatalyst-coated zeolite of the present invention is as follows.
Calcination step: A zeolite filter medium is prepared and placed in a crucible and heated at 600 ° C. for 2 hours in a furnace to volatilize the organic substances present in the zeolite and cool at room temperature.
Mixing zeolite and photocatalyst nanoparticles: After the calcination step, distilled water and photocatalyst particles are placed in the crucible containing the zeolite and mixed thoroughly with a magnetic stir bar or the like.
It is preferable that 100 g of zeolite and 20 g of photocatalyst particles are mixed per 100 g of the distilled water to prepare a 20% coated zeolite.
Add 100 mL of photocatalyst particles (TiO2 or composite photocatalyst, WO3 / TiO2) to 100 mL of distilled water in a crucible containing the prepared zeolite, and mix thoroughly with a magnetic stir bar or the like. To prepare a zeolite coated with a photocatalyst weight ratio of 20%, 20 g of photocatalyst particles (
Drying the mixture: The crucible containing the mixed solution prepared in the mixing step of the zeolite and the photocatalyst nanoparticles is placed in a dry oven and dried at 105 ° C for 12 hours to remove moisture.
Sintering Sintering step: The moisture-removed sintered mixture is heated in a furnace at about 600 ° C. for about 2 hours, so that the photocatalyst nanoparticles are tightly adhered to each other due to particle-to-particle aggregation at the surface of the zeolite So that it is solidified. Experiments show that heating for more than 2 hours did not provide a better effect for sintering the mixture.
Sintering of the photocatalyst nanoparticles occurs at a temperature higher than 600 ° C. Thereby causing entanglement between particles on the surface of the zeolite to coat the photocatalyst nanoparticles on the zeolite.
[Nanocomposite photocatalyst]
As a more specific embodiment of the present invention, the photocatalyst may be a nanocomposite photocatalyst. The nanocomposite photocatalyst is formed by a method of preparing a nanocomposite photocatalyst of a host nanoparticle and a guest nanoparticle, comprising: modifying the surface of the host nanoparticle with a basic aqueous solution; Mixing an aqueous solution containing the surface-modified host nanoparticles with an aqueous solution containing the guest nanoparticle precursor to form a complex; And a step of drying and calcining the formed complex.
The host nanoparticles may be at least one selected from the group consisting of
The basic aqueous solution used to modify the surface of the host nanoparticles may be NaOH having a concentration of 1M to 2M. Use of a basic aqueous solution within the above concentration range can improve bonding with guest nanoparticles without impairing desired physical properties of the host nanoparticles. The basic aqueous solution changes the surface by etching the crystal surface of the host nanoparticles to form an opening through which the guest nanoparticles can be adhered. Through such surface etching, it is possible to induce a strong coordination bond between the host nanoparticles and the guest nanoparticles, thereby improving the electron transfer efficiency of the host nanoparticles and the guest nanoparticles. As the bonding force between the host nanoparticles and the guest nanoparticles increases, the performance of the photocatalyst can be improved by reducing the phenomenon that the host nanoparticles oxidize the guest nanoparticles.
The step of modifying the surface of the nanoparticles may include slow stirring using a magnetic stir bar, for example, stirring for 2 to 3 hours. Within the above range, a desired degree of surface etching can be obtained.
The host nanoparticles may be added in an amount of 1 to 50 parts by weight based on 100 parts by weight of the host nanoparticles. The step of forming the complex may include stirring the two aqueous solutions for 1 hour to 2 hours. The step of drying the formed complex may be performed at a temperature of 90 to 105 degrees Celsius and may be performed for 20 to 24 hours. The thus-dried complex can be crystallized through the calcination step. The calcination step may be performed at a temperature of 300 to 400 degrees Celsius and may be performed for 4 to 6 hours. When performed within the above range, the nanocomposite photocatalyst can be efficiently produced, and the size of the produced nanoparticles can be made smaller. If the drying and calcination steps are carried out in this temperature range, the time taken to dry and calcine can be shortened.
The photocatalytic activity of WO3-TiO2 photocatalyst particles and WO3-BiVO4 photocatalyst particles, which are specific examples of the present invention, are sensitive to visible light and have a sufficient photocatalytic activity to have a heavy metal removal effect. The nanocomposite photocatalyst prepared by the method provided by the present invention can be sensitized not only in the UV region but also in the visible light region, and also has excellent photocatalytic activity through uniform nano-sized particles.
As a result, the nanocomposite photocatalyst produced by the method of the present invention can be effectively applied to the removal of heavy metals or harmful organic substances contained in the atmosphere or water, It is possible to efficiently remove air pollutants and water pollutants.
Experiments were carried out to confirm the removal efficiency of nitrogen oxide in the zeolite media coated with photocatalyst nanoparticles. 1 and 2 show the results of performing nitrogen oxide (NOx) removal experiments in air using the zeolite filter material coated with the photocatalyst nanoparticles of the present invention. More specifically, FIG. 1 compares the NOx removal efficiency of TiO2 particles and TiO2-coated zeolite (TCZ), FIG. 2 shows the NOx removal efficiency of zeolite (CCZ) coated with WO3 / TiO2 composite photocatalyst particles and a composite photocatalyst Respectively.
As shown in FIGS. 1 and 2, the photocatalyst nanoparticle-coated zeolite according to the present invention exhibits higher nitrogen oxide (NOx) removal efficiency than when the photocatalyst (
[Pitcher block coated with photocatalyst nanoparticles]
The zeolite coated with the photocatalyst nanoparticles described above can achieve the desired object of the present invention, but the surface layer may be formed as a permeable block according to a green infrastructure (for example, a parking lot package that can be subjected to non-point pollution treatment) . In this case, the surface of the permeable block may be coated by the following method.
Preparation of aqueous solution of sodium silicate: Sodium silicate aqueous solution is prepared by mixing 100 g of sodium silicate in 100 ml of distilled water and heating to 80-90 캜. (The temperature conditions of the aqueous solution and the concentration of sodium silicate are based on the solubility of sodium silicate Na2SiO3 in the Material Safety Data Sheet (MSDS) provided by the manufacturer)
Preparation of Coating Solution: Prepare photocatalyst coating solution by mixing aqueous solution of photocatalyst particles (TiO2 or WO3 / TiO2 composite photocatalyst) and aqueous solution of sodium silicate.
Coating Step: Put the prepared mixed solution into the air spray gun and spray evenly on the surface of the permeable block. Compressors were used for spraying with air spray guns, and the pressure in this example was about 0.4 MPa. The pressure is an empirical value for smoothly injecting the particles in the mixed solution upon spraying with the spray.
Drying step: Put the coated pellet block into the oven and dry for about 12 hours at around 70 ° C. This results in a water-permeable block coated with the photocatalyst nanoparticles.
FIG. 3 is a graph showing the results of performing a nitrogen oxide (NOx) removal experiment after coating
[Structure of media layer containing zero valence iron]
According to the present invention, a zeolite layer coated with photocatalyst nanoparticles on the surface of a green infrastructure is installed as described above. 4 is a conceptual view of a cross section of a lane garden as an embodiment to which the present invention is applied.
It can be seen that the
One of the main techniques of the present invention is to apply photocatalyst nanoparticles, which have been widely used for building self-cleaning and air pollution reduction purposes, on a building exterior to a zeolite as a water treatment material and apply it to urban green infrastructures such as lane gardens, And air quality at the same time.
By the way, NOx in the atmosphere is converted into nitric acid by photocatalyst, and the converted nitric acid is dissolved in water and penetrates into the ground during rainfall, which can act as a new pollutant. If there is no further denitrification treatment, groundwater contamination is a concern. Nitric acid is a major groundwater pollutant. Therefore, in the present invention, a dense material layer containing zero valence iron is disposed under the zeolite layer coated with the photocatalyst to achieve denitrification.
The filtering layer containing zero valence iron according to the present invention is further characterized by reducing and removing harmful organic substances such as oil substances and TCE, which are frequently generated in urban areas.
The
Specifically, the
The sandy media layer coated with Young's modulus nano iron can be implemented by the following method.
Mixing step: Appropriate mixing of iron ion distilled water, which is a precursor of sand and zero valent iron, at an appropriate ratio. It is preferable that the above mixing is strongly mixed so that there is no entanglement or precipitation of iron salts. Ultrasoftization can be used or acidic (around pH 4) can be adjusted to prevent flocculation or sedimentation as needed.
Solid Recovery Step: Add KBH4 or NaBH4 to the prepared mixture, mix and recover the resulting black solid. Through this process, the ferrous iron is reduced to zero valence iron.
Dry storage step: The recovered solids are stored under anaerobic conditions after vacuum drying (90 degrees, 2-3 hours). Since ferrous iron can oxidize under aerobic conditions, it is desirable to maintain anaerobic conditions during storage.
Formation of the media layer: When the infra-structure of the green nano-iron coated sand is prepared, it is installed as a filter media to form a sand filter media coated with Young's modulus nano iron.
In addition to the above-mentioned method of coating the zero valence iron nanoparticles on the sand, a filter medium containing zero valence iron may be formed by mixing the zero valent iron particles coated on the surface of the polymer with the sand by the polymer produced by the following method.
(ZVI) particle generation step: After a proper amount of Fe (II) or Fe (III) iron salt (
2Fe2 + + BH4- + 3H2O - > 2Fe0 + H2BO3- + 4H + + 2H2
Separation of zero valent iron: The generated black Fe0 particles are centrifuged and washed with distilled water to remove salt (such as NaCl or KCl) and residual boron hydride. The precipitate is separated from the solution, dried in a vacuum oven and stored under anaerobic conditions
Zero-valent iron encapsulation: Encapsulation of zero valent iron particles on a porous polymer matrix (alginate, agar, ethyl cellulose, polyvinyl alcohol, silica gel, etc.) prevents zero oxidation, It is possible to increase the life expectancy of the apparatus.
Mixed media forming step: Encapsulated zero valent iron beads are mixed with sand to form a mixed media layer. When the mixed media is formed by applying the mixed media, the pollutants in the water passing through the mixed media are diffused through the pores of the porous polymer to zero valence iron (in the case of nitrate (NO 3 -) or TCE).
In the encapsulation process, alginate is applied to the porous polymer matrix as follows.
Step 1: Sodium alginate is prepared and dissolved in distilled water to prepare an alginate solution.
Step 2: Dissolve calcium chloride (CaCl2) in distilled water to prepare a calcium chloride solution. Add an appropriate amount of maltodextrin, starch, or pectin to the prepared solution to increase the viscosity.
Step 3: While the above-mentioned calcium chloride solution and zero valence iron are gradually introduced into the above-mentioned alginate solution, nitrogen gas (N2) is purged to maintain anaerobic conditions at all times.
Step 4: Recover the finally generated encapsulated zero valence iron.
[Action of the present invention]
The operation of the present invention will be described. The present invention basically reduces pollutants, and not only removes organic matter and heavy metals in rain water runoff, but also reduces nitrogen oxides in the atmosphere as in the conventional natural type nonpoint pollution abatement facility.
Organic matter (rainwater, COD, BOD) in rainfall runoff
- The organic matter contained in the runoff effluent is adsorbed on the photocatalyst coated zeolite filter located on the surface layer of the rain garden, and finally oxidized and decomposed through photoreaction.
- Organic matter that has not been removed by adsorption on the surface layer is adsorbed and decomposed on subsequent soil layer and sand filter media (biochemical and chemical decomposition).
Heavy metals in runoff runoff
- Heavy metals in the water are removed by adsorption and photoreduction in the surface zeolite layer, or are removed by the ion exchange mechanism of the zeolite.
- Subsequent removal by adsorption / vegetation absorption in the soil layer.
Atmospheric nitrogen oxides
- During non-precipitation, the gaseous nitrogen oxides in the atmosphere are oxidized by the photocatalyst coated on the zeolite and converted into NO3- (nitric acid). Converted nitric acid is expected to be a trace amount of biochemical denitrification in subsequent soil layers. The following shows the process in which NOx is converted into nitric acid by the photocatalyst.
- Nitric acid, which is good in mobility in the soil, reaches the filter media containing zero valence iron and is chemically denitrified. The denitrification equation of nitric acid by the zero valent nano iron is as follows.
In particular, NOx in the atmosphere is converted into nitric acid by photocatalyst, and the converted nitric acid is dissolved in water and penetrates into the groundwater during rainfall. If there is no further denitrification treatment, groundwater contamination is concerned (nitric acid is a major groundwater pollutant). Therefore, the present invention aims at denitrification by installing a sand filter material containing zero valence iron as a lower layer in the lower part, and additionally reducing and removing harmful organic substances such as oil and TCE, which are frequently generated in urban areas.
[Other Embodiments of the Present Invention]
The foregoing description of the present invention has been presented for illustrative purposes only for the lane garden. However, the technical idea of the present invention is not limited thereto.
For example, the present invention can be applied to a flower bed of a parking lot. FIG. 5 is a view illustrating a parking lot flower bed as another embodiment of the present invention.
Meanwhile, a complex green infrastructure to which the present invention is applied is presented. The reason for the so-called 'complex' is not only the rain gardens, but also the combination of wetlands and infiltration ditches as initial settlement sites. As described above, the technical idea of the present invention may be applied to the lane garden of the composite green infrastructure of the present invention. In the present embodiment and the following embodiments, the technical idea of the present invention is applied to the infiltration ditch. Of course, such an application does not limit the application of the technical idea of the present invention, but can be applied selectively.
6 to 10 are views showing a composite green infrastructure to which the present invention is applied. 6 is a top view of a composite green infrastructure to which the present invention is applied. Figs. 7 and 8 show the first embodiment of the cross section taken along line A-A 'of Fig. 6, and Fig. 8 is an enlarged view of a portion of Fig.
The composite
The space in which the complex green infrastructure can be installed varies. If there is a need to reduce non-point pollutants caused by impervious surfaces, a complex green infrastructure can be applied. Rainfall runoff from infiltrating roads, parking lots, or roofs enters the complex green infrastructure.
The rainfall runoff flows into the
The rainwater effluent flowing into the
The rainfall runoff via the lane garden (60) is finally introduced into the infiltration ditch (70). On the other hand, the inflow into the
On the other hand, a
For this, an embodiment of the present invention forms an
Considering the climatic characteristic in which rainfall is concentrated, rapid rainfall runoff can be limited only by the
Figs. 9 and 10 show a second embodiment of the cross section taken along line A-A 'of Fig. 6, and Fig. 10 is an enlarged view of a portion of Fig. The present embodiment is configured to treat only the rainfall falling from the top to the bottom of the photocatalyst surface layer at the time of the heavy rain as described above, and to rapidly discharge the rainwater inflow water flowing from the impervious layer at the side to the separate piping.
The
The height of the loop drain is formed to be lower than the partition wall between the lane garden and the infiltration ditch. Through which rainwater flowing out of the rain gard through the weir quickly flows through the loop drain and the pore pipe. As a result, the filter material layer including the photocatalyst formed in the infiltration trench can be stably maintained.
According to one aspect of the present invention, there is provided a photocatalytic surface layer filter medium comprising a photocatalytic surface layer comprising a photocatalytic filter layer as a surface layer, wherein a loop drain is formed outside the partition wall surrounding the photocatalytic surface layer filtering medium zone, And the photocatalyst surface layer filter material is not lost.
Although the present invention has been described with reference to specific embodiments as described above, the present invention is not limited thereto. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention.
1: Lane Garden
2: Parking lottery
3: Compound Green Infrastructure
10: zeolite layer coated with photocatalyst nanoparticles
20: Filter layer containing zero valence iron
30: soil layer
31: Vegetation
40: Gravel drainage layer
50: Wetlands
51: Aquatic plants
52: Weir
60: Lane Garden
61: Vegetation
62: Loop drain
70: penetration ditch
71: Filter layer containing a photocatalyst
72: Inflow ball
73: Pipe
Claims (12)
Wherein the surface layer of the two or more filter media is a filter medium layer containing a photocatalyst capable of treating nitrogen oxides in the air while reducing nonpoint pollutants,
A filter material layer containing zero valence iron is disposed under the filter material layer containing the photocatalyst,
Wherein nitric acid converted from nitrogen oxide in the air by the surface layer which is a filter medium containing the photocatalyst is dissolved in water at the time of rainfall and denitrified by the filter media layer containing the zero valent iron
Green infrastructure.
Wherein the surface layer is a zeolite layer coated with a photocatalyst,
And a soil layer capable of vegetation is formed in the lower part thereof
Green infrastructure.
The photocatalyst-coated zeolite may include:
Preparing a zeolite filter medium, placing the zeolite filter material in a crucible and heating the furnace to volatilize the organic substances present in the zeolite,
Mixing the zeolite with the photocatalyst nanoparticles in which distilled water and photocatalyst particles are placed in the crucible containing the zeolite after the calcination step and sufficiently mixed with a magnetic stir bar,
A drying step of placing the crucible containing the mixed solution prepared in the step of mixing the zeolite and the photocatalyst nanoparticle in a dry oven and drying the mixture;
And a mixture sintering step of heating the moistened mixture in a furnace so that the photocatalyst nanoparticles aggregate on the surface of the zeolite so as to firmly adhere to each other and to be solidified. ≪ / RTI >
Green infrastructure.
In the step of mixing the zeolite and the photocatalyst nanoparticles,
100 g of zeolite and 20 g of photocatalyst particles are mixed per 100 g of the distilled water to prepare a photocatalyst-coated zeolite
Green infrastructure.
Characterized in that the green infrastructure is a lane garden, filter strip or flower bed
Green infrastructure.
The photocatalyst is a nanocomposite photocatalyst,
The nanocomposite photocatalyst is formed by a method of producing a nanocomposite photocatalyst of host nanoparticles and guest nanoparticles,
Modifying the surface of the host nanoparticles with a basic aqueous solution; Mixing an aqueous solution containing the surface-modified host nanoparticles with an aqueous solution containing the guest nanoparticle precursor to form a complex; And a step of drying and calcining the formed complex. The method for producing a nanocomposite photocatalyst according to claim 1,
Green infrastructure.
Wherein the surface layer is a photocatalyst-coated permeable block layer
Green infrastructure.
The photocatalyst-
Preparing a mixed solution by mixing an aqueous solution of a photocatalyst and an aqueous solution of sodium silicate;
Injecting the mixed solution into an air spray gun and spraying the mixed solution onto the surface of the permeable block; And
And the step of placing the post-injection pervious block in an oven and drying it.
Green infrastructure.
And the pressure of the air spray gun is 0.4 MPa.
Green infrastructure.
The permeable block is placed in an oven and dried at 70 DEG C for 12 hours
Green infrastructure.
And a free layer disposed on the lower surface of the surface layer containing the photocatalyst and containing zero valence iron,
Wherein nitric acid converted from nitrogen oxide in the air by the surface layer which is a filter medium containing the photocatalyst is dissolved in water at the time of rainfall and denitrified by the filter media layer containing the zero valent iron
Media layer.
The barrier metal layer containing the zero valence iron may be formed by a method comprising the steps of:
After forming the zero valent iron particles, the zero valent iron particles are centrifuged and washed with distilled water to remove the salt (such as NaCl or KCl) and the remaining boron hydride, and the step of encapsulating the zero valent iron particles with a porous polymer matrix Wherein the porous polymer matrix is formed by mixing the encapsulated zero valent iron particles with sand, wherein the porous polymer matrix is alginate,
Preparing sodium alginate by dissolving it in distilled water to prepare an alginate solution, adding at least one of maltodextrin, starch, and pectin to a calcium chloride solution in which calcium chloride (CaCl2) is dissolved in distilled water Maintaining the anaerobic condition by purging the nitrogen gas (N2) while adding the calcium chloride solution and the zero-valent iron particles to the alginate solution, and recovering the resulting encapsulated zero valent iron particles And is characterized in that
Green infrastructure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020160024702A KR101768705B1 (en) | 2016-02-29 | 2016-02-29 | PHOTOCATALYST COATING ZEOLITE SURFACE MEDIA and GREEN INFRASTRUCTURE USING THE SAME |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020160024702A KR101768705B1 (en) | 2016-02-29 | 2016-02-29 | PHOTOCATALYST COATING ZEOLITE SURFACE MEDIA and GREEN INFRASTRUCTURE USING THE SAME |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| KR101768705B1 true KR101768705B1 (en) | 2017-08-17 |
Family
ID=59753128
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020160024702A KR101768705B1 (en) | 2016-02-29 | 2016-02-29 | PHOTOCATALYST COATING ZEOLITE SURFACE MEDIA and GREEN INFRASTRUCTURE USING THE SAME |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR101768705B1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102024748B1 (en) * | 2018-11-06 | 2019-09-24 | 주식회사 카리스 | Plastic boundary stone of road capable of removing NOx |
| KR20210070090A (en) | 2019-12-04 | 2021-06-14 | 단국대학교 천안캠퍼스 산학협력단 | Method for preparing metal-doped photocatalytic nanoparticles without using additives |
| WO2024053969A1 (en) * | 2022-09-05 | 2024-03-14 | 경북대학교 산학협력단 | Method for manufacturing composite photocatalyst filter activated by oxygen vacancy and air purification filter according thereto |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100906560B1 (en) | 2007-06-27 | 2009-07-07 | 대한주택공사 | Treatment method of greywater using constructed wetland and apparatus thereof |
| KR101158247B1 (en) * | 2010-12-14 | 2012-07-20 | 주식회사 동호 | System for ecologically restoring a river and purifying fluid using wetland structure |
-
2016
- 2016-02-29 KR KR1020160024702A patent/KR101768705B1/en active IP Right Grant
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100906560B1 (en) | 2007-06-27 | 2009-07-07 | 대한주택공사 | Treatment method of greywater using constructed wetland and apparatus thereof |
| KR101158247B1 (en) * | 2010-12-14 | 2012-07-20 | 주식회사 동호 | System for ecologically restoring a river and purifying fluid using wetland structure |
Non-Patent Citations (1)
| Title |
|---|
| Seung Yong Chai 외 2인, Journal of Electroceramics, 2006, 17권2호, 909-912쪽* |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102024748B1 (en) * | 2018-11-06 | 2019-09-24 | 주식회사 카리스 | Plastic boundary stone of road capable of removing NOx |
| WO2020096333A1 (en) * | 2018-11-06 | 2020-05-14 | 주식회사 카리스 | Plastic road barrier capable of removing nitrogen oxide |
| KR20210070090A (en) | 2019-12-04 | 2021-06-14 | 단국대학교 천안캠퍼스 산학협력단 | Method for preparing metal-doped photocatalytic nanoparticles without using additives |
| WO2024053969A1 (en) * | 2022-09-05 | 2024-03-14 | 경북대학교 산학협력단 | Method for manufacturing composite photocatalyst filter activated by oxygen vacancy and air purification filter according thereto |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Nasir et al. | A review on floating nanocomposite photocatalyst: fabrication and applications for wastewater treatment | |
| JP4494017B2 (en) | Method for producing a titanium oxide product having an active surface and method for using the titanium oxide product in a water treatment process | |
| Li et al. | Phosphate adsorption on metal oxides and metal hydroxides: A comparative review | |
| KR101768703B1 (en) | ZERO-VALENT IRON COATING SAND MEDIA and GREEN INFRASTRUCTURE USING THE SAME | |
| KR101768700B1 (en) | Hybrid green infrastructure for protecting surface to reduce air pollutants | |
| Song et al. | Photocatalytic enhancement of floating photocatalyst: Layer-by-layer hybrid carbonized chitosan and Fe-N-codoped TiO2 on fly ash cenospheres | |
| US8758607B2 (en) | Water treatment | |
| KR101768705B1 (en) | PHOTOCATALYST COATING ZEOLITE SURFACE MEDIA and GREEN INFRASTRUCTURE USING THE SAME | |
| Niu et al. | Cobalt oxide loaded graphitic carbon nitride as adsorptive photocatalyst for tetracycline removal from aqueous solution | |
| Thambiliyagodage | Efficient photocatalysis of carbon coupled TiO2 to degrade pollutants in wastewater–A review | |
| WO2000061290A1 (en) | A photocatalyst | |
| KR20130109923A (en) | Soil composition for water treatment and the use thereof | |
| Jafari et al. | Synthesis of new composite based on TiO2 immobilized in glass fibers for photo-catalytic degradation of chlorobenzene in aqueous solutions | |
| Tijani et al. | Synthesis and characterization of Ag 2 O/B 2 O 3/TiO 2 ternary nanocomposites for photocatalytic mineralization of local dyeing wastewater under artificial and natural sunlight irradiation | |
| Saleh et al. | Photooxidation/adsorption of arsenic (III) in aqueous solution over bentonite/chitosan/TiO2 heterostructured catalyst | |
| Kadhim et al. | The most important parameters that affect the photocatalytic activity of ZnO nanostructures against organic dyes: a review | |
| Yuan et al. | Enhanced photocatalytic oxidation of humic acids using Fe 3+-Zn 2+ co-doped TiO 2: The effects of ions in aqueous solutions | |
| Yaghoobi Rahni et al. | Facile and green synthesis of Cu3V2O8 nanostructures via Moringa peregrina natural extract as a high performance photo catalyst | |
| Ghosh et al. | Redox-assisted arsenic (III) adsorption for removal from aqueous solution by cerium (IV)-incorporated zirconium oxide nanocomposites | |
| KR101344235B1 (en) | Adsorbent for eliminating harmful ions using alum sludge and method for producing the same | |
| Mohamed et al. | Doping cadmium oxide into mesoporous zinc oxide matrix for enhanced removal/reduction of Hg (II) Ions | |
| JP2000107608A (en) | High strength photocatalyst, its production and its use | |
| Andish-Lifshagerd et al. | Facile synthesis of ZnO/CeO2/CeFeO3 photocatalysts sensitive to visible light with tandem nn heterojunctions and improved performance towards tetracycline and dye effluent removals | |
| Basnet et al. | Nanocomposites of ZnO for Water Remediation | |
| Hiep et al. | Greener Method for the Application of TiO 2 Nanoparticles to Remove Herbicide in Water |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| E701 | Decision to grant or registration of patent right | ||
| GRNT | Written decision to grant |