KR100433644B1 - Porous Polymer Matrix Formed with Activated Carbon and Zeolite for Biofilter and Method for Preparing the Same - Google Patents

Abstract

PURPOSE: Provided is a method of preparing porous foamed polymer support carrier for a bio-filter by which provided porous support carrier is able to biologically remove bad smell materials and volatile organic compounds with high efficiency. CONSTITUTION: The method comprises steps of (a) after mixing 5-9 wt.% of a foamable polymer selected from the group consisting of polyvinylacetal, polyurethane, polystyrene and polyethylene, 5-9 wt.% of aldehyde-based compound and 72-88 wt.% of water, mixing it with 2-10 wt.% of activated carbon powder and/or zeolite to obtain a first mixture; (b) mixing each 1-30 parts by weight of soluble starch and/or dextrin with 100 parts by weight of the first mixture to obtain a second mixture; (c) heating the second mixture at a temperature of 60-80°C to melt; (d) adding 10-30 parts by weight of a decomposable foaming agent and an acid to 100 parts by weight of the molten second mixture to obtain a third mixture; (e) after putting the third mixture in a mold, reacting it at a temperature of 50-80°C to obtain a sponge foam or non-woven fabric type support carrier; and (f) washing the obtained sponge foam or non-woven fabric type support carrier to remove the starch and/or dextrin.

Description

Porous Polymer Matrix Formed with Activated Carbon and Zeolite for Biofilter and Method for Preparing the Same}

The present invention biologically removes odorous substances and volatile organic compounds (VOCs) emitted from various environmental base facilities such as sewage treatment plant, manure treatment plant, livestock wastewater treatment plant, food waste treatment plant, and various industrial facilities such as petrochemical plant and painting plant. The present invention relates to a porous foamed polymer carrier for biofilter for removal by a method and a method for manufacturing the same, and more particularly, to a bio-friendly polymer material, an activated carbon powder, a zeolite powder, a soluble substance, etc. are mixed with a blowing agent and foamed. By controlling the amount and foaming speed, it has a large specific surface area and forms an excellent hydrophilic and porous open cell structure.It is well developed fine pores by activated carbon, zeolite, etc., and porous foam that does not cause desorption of activated carbon powder and zeolite powder. A polymer carrier and a method for producing the same.

Current deodorization technologies include physical and chemical treatment methods such as activated carbon adsorption, chemical liquid cleaning, ozone oxidation, combustion deodorization (incineration), and biological treatment methods such as biofilter, soil microbial treatment, and aeration tank deodorization. It is used. However, activated carbon adsorption is inexpensive because expensive activated carbon must be replaced on a regular basis, and the chemical liquid cleaning method requires excessive operating costs and secondary pollutants due to excessive chemical consumption. Ozone oxidation method is to oxidatively decompose malodorous components by oxidizing by ozone, but there is a problem of residual ozone as a deodorization method that uses a concealment effect by ozone itself. Combustion deodorization produces secondary air pollution.

In addition, the soil microbial treatment method and aeration tank deodorization method of the biological treatment method has the disadvantage of requiring a lot of power costs and a large site because the pressure loss of the entire system is high and the amount of waste gas that can be treated per unit area of the device is very small. Therefore, the initial investment cost and operation cost are low, and it is very economical compared to other deodorization methods, and it is easy to treat various odors and volatile organic compounds, and biofilter technology that generates little secondary pollutants after treatment is widely used. .

The biofilter, which is a biological deodorization method using decomposition by microorganisms attached to the carrier, introduces gaseous odors or volatile organic compounds into the reactor and passes through the interface of the biofilm formed around the carrier. At this time, odors or volatile organic compounds are absorbed into the biofilm, diffused into the microorganisms, and finally decomposed by the microorganisms.

Therefore, biofilter is an important driving factor such as pollutant loading, moisture, temperature, pH, nutrient source, gas pretreatment, and the like. In order to operate the biofilter effectively, several things should be noted in selecting the carrier material.

First, in order to maintain high decomposition rate of pollutants, it is necessary to make optimum conditions for the microorganisms resident in the carrier. To this end, the retention of moisture, which is essential for maintaining the active material, must be high. Second, the particle size distribution and the porous structure of the carrier material It should provide as much reaction area as possible to secure the area for microbial attachment and growth, and high adsorption rate of microorganisms and treated contaminants. Third, the pressure loss can be kept low and the degree of compression with high porosity to prevent residence time reduction. Must be kept to a minimum, and at the same time, sufficient strength and light conditions to support the weight increase due to the growth of microorganisms must be met at the same time. Finally, physical and chemical stability without decomposing the carrier and mechanical abrasion occurs. Therefore, maintenance and replacement frequency should be reduced.

As the carriers of early biofilters, mainly processed and unprocessed forms using natural materials such as soil, peat moss, bark and compost as raw materials were used. However, most of them are composed of organic materials, which initially show high removal rate due to high physical adsorption and good water retention, but the decomposition of the carrier itself occurs, the pressure loss increases rapidly due to consolidation, and the flow of air is consistent with the carrier layer. There is a shortcoming that the maintenance and replacement cycle of the carrier is short because the drift phenomenon does not flow. In addition, in the case of inorganic material carriers such as ceramics, the biotrickling filter system is mainly applied, so it is suitable for the high solubility of pollutants in water, and it requires nitrogen, phosphorus, and inorganic salts necessary for the formation of a large amount of water and biofilm. As a result, a large amount of waste water may be generated, and the specific gravity of the carrier may be high.

Therefore, in order to select a carrier that is closest to the selection conditions of the above-mentioned carrier and has good microbial activity per unit weight and is easy to maintain, research on foamed polymer carriers in which the synthetic material is physically and chemically processed in accordance with the characteristics of the microorganism is carried out. A lot has gone on.

However, foamed polymer carriers are easy to manufacture in the desired shape, are very light, have a high water content, and have high porosity, so that some major requirements as biofilter carriers are fulfilled, but the specific surface area is not large in itself and is physically / chemically unstable. It does not have the ability to adsorb microorganisms and contaminants, so the attachment and growth of microorganisms is slow and the buffer capacity against overload and poor load of contaminants is low.

In particular, it was pointed out that the slow growth of independent nutrient microorganisms known to remove inorganic malodorous gases such as ammonia and hydrogen sulfide are not easy to grow and grow. Therefore, in order to make up for these drawbacks, a technique of coating a clay material or coating finely divided activated carbon on an artificial material such as a polymer sponge (polyurethane) or a plastic has been developed, but a problem that a specific surface area is reduced due to an adhesive or the like has arisen. .

Accordingly, the present inventors have found that the porous carrier for biologically removing odorous substances and volatile organic compounds (VOCs) discharged from various environmental foundations and industrial facilities, and has been removed from the conventional technology to coat the surface from the conventional technology Efforts have been made to improve the problems such as clogging caused by the adhesive. As a result, the activated carbon powder and the zeolite powder are mixed and foamed together with a polymer material to prepare a porous foamed polymer carrier, and the present invention is carried out by comparison with existing carriers. The present invention has been completed by demonstrating the superiority and practicality of the carrier according to the present invention.

After all, the main object of the present invention is not only excellent mechanical strength and durability, but also physically, chemically and biologically stable, but also excellent in physical properties, physically adsorbing microorganisms and contaminants, and exhibiting excellent removal rate, stable load, etc. The present invention provides a carrier for a biofilter and a method of manufacturing the same, which show high processing efficiency even with a short residence time compared to a filter.

Figure 1a is an electron micrograph at 100 times magnification of the porous foam polymer carrier according to the present invention.

Figure 1b is an electron microscope photograph of a 300 times magnification of the porous foam polymer carrier according to the present invention.

Figure 1c is an electron micrograph of a 3000 times magnification of the cross section of the porous foamed polymer carrier attached to the microorganism.

Figure 2a is a FISH result photograph of the microorganisms attached to the carrier after 50 days of operation in the ammonia gas removal biofilter filled with a porous porous foam polymer carrier.

2b is a FISH result photograph of microorganisms attached to the carrier after 50 days of operation in the ammonia gas removal biofilter filled with the activated carbon powder and the zeolite powder coated porous foam polymer carrier.

Figure 2c is a FISH result photograph of the microorganisms attached to the carrier after 50 days of operation in the ammonia gas removal biofilter filled with a porous polymer carrier foamed by mixing activated carbon powder and zeolite powder.

In order to achieve the above object, the present invention (a) any one of 5 to 9% by weight of the expandable polymer selected from the group consisting of polyvinyl acetal, polyurethane, polystyrene and polyethylene, 5 to 9% by weight of the aldehyde compound and water 72 Mixing ~ 88% by weight, followed by mixing 2-10% by weight of activated carbon powder and / or zeolite powder to obtain a first mixture, (b) removing starch and / or dextrin, which are soluble substances, into the first mixture. 1 to 30 parts by weight of each mixture, to 1 to 30 parts by weight of the mixture to obtain a second mixture, (c) heating the second mixture to 60 ~ 80 ℃ to melt, (d) to the molten mixture 10 to 30 parts by weight of a decomposable blowing agent and an acid are added to 100 parts by weight of the second mixture to obtain a third mixture. (E) The third mixture is added to a mold and reacted at 50 to 80 ° C. to form a sponge. Or carriers in the form of nonwovens To obtain and (f) provides the obtained sponge form or the method of bio-filter porous cellular polymeric carrier to clean the carrier of non-woven fabric form includes removing dissolution of starch and / or dextrin.

In the present invention, the mold may be characterized in that the hexahedron shape having a horizontal, vertical and height of 10mm to 20mm or a circular model having a diameter of 10mm to 20mm.

In the present invention, the second mixture is at least one substance selected from the group consisting of sodium alginate, CMC (carboxymethyl cellulose) and CMS (carboxymethyl starch) in addition to starch and / or dextrin, 1 to 30 parts by weight based on 100 parts by weight of the first mixture. It can be characterized by containing a weight part.

The present invention also provides a porous foamed polymer carrier for a biofilter containing an activated carbon powder and a zeolite powder prepared by the above method and having an internal porosity of 95% or more.

Porous foamed polymer carrier according to the present invention in the form of sponge foam or non-woven fabric processed from polyvinyl acetal, polyurethane, polystyrene or polyethylene as a raw material by adding activated carbon powder, zeolite powder, soluble material and the like together with the blowing agent and foaming Activated charcoal powder, zeolite powder, etc. are mixed in the carrier, no detachment occurs, and large pores more than 0.5mm formed by blowing agent, intermediate cells less than 0.5mm formed by soluble substance, activated carbon powder, zeolite powder, etc. It is distributed and has the characteristic of forming a very large specific surface area.

The present invention will be described in more detail as a method for producing a porous foamed polymer carrier using polyvinyl alcohol (PVA) resin. First, PVA (polyvinyl alcohol), formaldehyde (formaldehyde), activated carbon powder, zeolite powder and water are mixed, but the mixing ratio of PVA resin is 5% by weight or more for the mechanical strength of the sponge, considering the production cost and ease of foaming It is preferable to set it as 9 weight% or less.

In the present invention, formaldehyde is used as the aldehyde-based compound, but acetaldehyde, propionaldehyde, butylaldehyde, valeraldehyde and the like can also be used. It may be desirable to include activated carbon powder and zeolite powder as much as possible for the development of micropores, but in case of PVA, when the content of activated carbon powder and zeolite powder is more than 10% by weight of the total, it is difficult to foam and the micropore is less than 2% by weight. This is not formed sufficiently.

At this time, the activated charcoal powder is finely pulverized coconut shell and bituminous coal, respectively, and is prepared by activating by steam regeneration of the non-combustion method in the temperature range of 750 ~ 1050 ℃ mixed 1: 1 by volume. Activated carbon powder has a particle size in the range of 200 to 800 mesh for even foaming, specific surface area is about 800 ~ 1,000m ² / g, iodine adsorption power is used at 950 ~ 1,000mg / g. In addition, the zeolite powder is a natural zeolite called clinoptilolite or a mixture of an aluminum solution and a silica solution by a hydrogel process to form a gel state, and then a zeolite synthesized through hydrothermal reaction is mainly used. The specific surface area is about 800 to 1,000 m ² / g and the ion exchange capacity is about 1.6 to 2.0 meq / g. If the organic solvent (formaldehyde) is 5% by weight or less, an acetal reaction with PVA does not sufficiently occur, and an excess amount of the organic solvent (formaldehyde) is 9% by weight or more. It is preferable to mix 72-88 weight% of water in this.

After mixing the blended raw materials, 1-30 parts by weight of soluble starch and dextrin were respectively mixed with respect to 100 parts by weight of the mixed first mixture, and at least one of sodium alginate, CMC (carboxymethyl cellulose) and CMS (carboxymethyl starch) One or more is selected and 1-30 parts by weight is added to 100 parts by weight of the first mixture to obtain a second mixture, which is then heated to 60-80 ° C. to melt. Since the size of the cell formed by the starch and dextrin is formed as the starch or dextrin particles are eluted, the size of the cell can be adjusted according to the needs of the intermediate cell of the sponge with a size of 0.5 mm or less. In addition, sodium alginate, CMC and CMS is a kind of emulsifier to improve the quality of the product by uniformly dispersing the cells produced by the blowing agent.

After melting, a decomposable blowing agent and an acid which are decomposed by the acid to generate a gas are added. Toluene sulfonyl hydrazide (TSH), azodicarbonamaid (ADCA), dinitroso pentamethylene tetramine (DPT), benzenesulfonyl hydrazide (OBSH) NaHCO _3, CaCO _3, Al powder, Zn powder, Mg powder, etc. As the acid, sulfuric acid or hydrochloric acid may be used. 10-30 parts by weight of the decomposition type blowing agent is added to 100 parts by weight of the second mixture, and then 10-30 parts by weight of sulfuric acid or hydrochloric acid is added to obtain a third mixture. In order to maximize the porosity at this time, the blowing agent is decomposed by acid to generate gas, and the blowing agent is preferably 10 parts by weight or more, and preferably 30 parts by weight or more because the surface of the sponge foam becomes very rough. Sulfuric acid and hydrochloric acid also catalyze the foam formation.

The third mixture is introduced into a mold, heated to 50 to 80 ° C., and reacted for about 24 hours to form a foam. By this reaction, starch and dextrin, which are soluble substances, are hydrolyzed, and polyvinyl alcohol and formaldehyde cause acetal reaction to produce polyvinyl acetal. In addition, by the reaction, the blowing agent is decomposed by the acid to generate gas, and the gas cell is formed by the generated gas to form a foam.

The formed foam is washed with water to elute and remove soluble starch and dextrin to form a sponge foam having cells of various sizes.

The porous foamed polymer carrier prepared in this way has excellent water content and adsorption capacity, so it is only 24 hours in the biological reaction tank (aeration tank) of artificially cultured microbial culture tank, various environmental foundation facilities, and industrial wastewater treatment facilities. Even if it is supported, the inoculation of microorganisms is excellent, and it can serve as an excellent bio-immobilization carrier for removing odor and volatile organic compounds.

1A (x100x) and 1b (x300x) of the micrograph which enlarged the cross section of the porous polymeric carrier which foamed the activated carbon powder and zeolite powder by this invention simultaneously are shown. In addition, electron micrographs of the microorganisms attached to the porous foamed polymer carrier after 50 days of operation in the ammonia gas removal biofilter are shown in FIG. 1C (× 3,000 times).

The porous foamed polymer carrier mixed with the activated carbon powder and zeolite powder prepared by the above method maximized the specific surface area from large cells of 0.5 mm or more to intermediate cells and micropores of less than 0.5 mm. In addition, 100 mm (width) × 100 mm (length) × 100 mm (height) cube polyvinyl acetal sponge foam that has been accurately cut for porosity testing is immersed in water for 24 hours, taken out, dried at 110 ° C for 24 hours, and absorbed. The porosity was tested by checking the weight before and after drying the water, and calculating the volume containing the dried water, and the porosity was 96 ± 0.5%, which was 95% or more.

Therefore, the porous polymer carrier foamed simultaneously with the activated carbon powder and zeolite powder according to the present invention has a high enough space for microorganisms to attach and high material transfer rate to the inside, resulting in excellent biodegradation of odor and volatile organic compounds by aerobic microorganisms, and hydrophilicity. Each cell is interconnected with each other, and physical adsorption by activated carbon powder and zeolite powder occurs, thus acting as a protective film of microorganisms in external rapid reaction (impact load of contaminants). In addition, it has excellent mechanical strength and durability by improving wear resistance and physical strength.

It is possible to manufacture the existing foamable polymer carrier in the desired shape, and it is very light, has a high water content, and has a large porosity, so that some requirements of the biofilter carrier are satisfied. Very long period of adhesion and stabilization, no buffering capacity due to poor load, impact load, etc., normalization period is very long when the activity of microorganism decreases, and physical / chemical instability, especially slow growth rate known to remove ammonia, hydrogen sulfide, etc. It is a significant improvement in the disadvantages of difficult attachment and growth of nutrient microorganisms.

In addition, in order to compensate for these disadvantages, a technique of coating a clay material on a polymer sponge or an artificial material or coating fine powdered activated carbon has a problem that the specific surface area is reduced or the activated carbon powder and the zeolite powder fall off due to an adhesive. In the porous foamed polymer carrier, the activated carbon powder and the zeolite powder are mixed with the foam and foamed, so that problems such as reduction of specific surface area due to an adhesive or separation of the activated carbon powder and zeolite powder do not occur.

Therefore, the porous foamed polymer carrier mixed with activated carbon powder and zeolite powder prepared by the above method may be used as a biofilter carrier for treating odor and volatile organic compounds generated in various environmental foundations and industrial facilities. The filter is a particulate contaminant removal device included in the mixed pollutant gas, a transfer unit for moving the primary treated pollutant gas to the lower or upper biofilter, the biofilter housing filled with the porous foam polymer carrier according to the invention, pH and temperature is It is characterized in that it is automatically controlled and includes a device for automatically supplying the moisture and nutrients to the microorganisms attached to the carrier, the microorganism is a microorganisms purely cultured by fermentation tanks or biological waste / wastewater treatment apparatus of various environmental basic facilities and industrial facilities Inoculate the microorganisms obtained from the bioreactor (aeration tank) use.

The present invention will be described in detail through the following examples. However, these examples are only for the purpose of understanding the present invention, the scope of the present invention is not limited by these examples.

<Example 1>

In the biofilter system for removing odors and volatile organic compounds, sponge foam or nonwoven fabric such as polyvinyl acetal, polyurethane, polystyrene or polyethylene may be used as the porous foamed polymer carrier including activated carbon powder and zeolite powder. Mechanical wear is closely related to the life of the carrier and the cause is mostly due to the material of the polymer.

Therefore, in this experiment, a mechanical wear test was performed on a polyvinyl acetal carrier and a polyurethane carrier according to Korean Patent No. 346915 and a Linpor carrier of Linde, Germany. The experiment was carried out to evaluate the carrier by the Korea Research Institute for Chemical Testing, and the aeration tank (5L) made of concrete was made and surface treatment was not performed to provide harsh conditions. Air was injected using acid stones to provide harsh conditions. For this purpose, 200 times of air was supplied to the air injection amount in the general activated sludge process. The test period was set to 100 days, the minimum period in which the form of wear could be observed on the outer part of the carrier. The average wear lengths at the corners of the three carriers were measured using a microscope equipped with image analysis. The polyvinyl acetal carrier used as a comparison in the present invention is prepared by the method described in Korean Patent No. 346915.

Wear test results according to the material of the carrier Polyvinyl acetal carrier Polyurethane carrier Linpor carrier Abrasion length after 100 days of testing period (mm) 0.1400 0.3552 0.4128

As a result of the abrasion test of the foamed polymer carrier made of PVA, it was found to be more wear resistant than the polyurethane carrier and the Linpor carrier. The foamed polymer carrier made of PVA is a natural spongy tissue, which has a specific gravity close to water in the state of absorbing water, and is different from that of conventional carriers such as rubber and polyurethane sponge, and is highly resistant to chemicals and abrasion. It has a characteristic that it does not decompose, and the contact angle is very small, which is in agreement with the existing research results that the adhesion and growth of microorganisms are superior to other polymer carriers as hydrophilic materials. However, the material of the foamed polymer carrier is not limited to PVA, and the foamed polymer carrier prepared using polyurethane, polystyrene or polyethylene may be used alone, or may be mixed with the foamed polymer carrier manufactured using PVA. have.

<Example 2>

Removal experiments of odor gas (ammonia gas) were carried out using a biofilter filled with a foamed polymer carrier according to the present invention. Porous polyvinyl acetal polymer foam carrier without activated carbon powder and zeolite powder, polyvinyl acetal polymer foam carrier coated with 5% activated carbon powder and zeolite powder, and 5% of activated carbon powder and zeolite powder, respectively Polyvinyl acetal polymer carriers were mixed and foamed together, and were filled in MLSS 4,500mg / L activated sludge collected in Chuncheon-si sewage treatment plant for 24 hours, aerated and filled in 5L biofilters of working volume. 30 ppmv of ammonia was added for 3 days, and 50 to 200 ppmv of ammonia was added for 50 days after the stabilization period of the microorganism, respectively, and the removal rate of the odor gas was observed.

The tower residence time in the reactor was adjusted to 5 seconds and the concentration of ammonia gas was measured at each of the inlet and outlet samples of the acrylic reactor. The measuring method was measured daily using gastec (GASTEC, Japan) as a detection tube method. Table 2 shows the ammonia removal rates performed during this period.

Average Ammonia Removal Rate by Addition Type of Activated Carbon Powder and Zeolite Powder Ammonia concentration General PVA Carrier (Domestic Registration No. 346915) Activated Carbon 5% and Zeolite 5% Coated PVA Carrier 5% activated carbon and 5% zeolite mixed PVA carrier (invention) 50 ppmv 62% 94% 100% 100 ppmv 70% 88% 99% 150 ppmv 88% 83% 99% 200 ppmv 79% 89% 98%

Ammonia gas removal biofilter filled with porous polyvinyl acetal polymer carrier foamed by mixing activated carbon powder and zeolite powder according to the present invention is superior to the average of more than 98% from the beginning of operation compared to the biofilter using other carriers in the same period. Excellent ammonia gas removal rate was shown. In addition, general polyvinyl acetal carrier showed a low removal rate at a relatively low concentration range of 50 to 100 ppmv initially and high removal rate in a biofilter filled with polyvinyl acetal polymer to which the remaining activated carbon powder and zeolite powder were added. It appears to be due to adsorption and rapid attachment of microorganisms.

<Example 3>

After 50 days of operation of the biofilter for removing ammonia gas according to Example 2, the porous polyvinyl acetal polymer foam carrier without activated carbon powder and zeolite powder, activated carbon powder and zeolite powder were each coated with adhesive by 5%. Combined with rRNA oligonucleotide probe, one of the latest molecular biology techniques for the observation of complex microorganisms attached to polyvinyl acetal polymer foam carrier and activated polyvinyl acetal polymer carrier mixed with activated carbon powder and zeolite powder. Fluorescence in situ hybridization (FISH) was used. This method is one of the latest molecular biological techniques for the qualitative and quantitative determination of specific microorganisms.

In the experiment, 20 carriers were collected from each biofilter, washed with distilled water, and then placed in a 50ml cornical tube and strongly vortexed to separate the biofilm, followed by fixing at 4 ° C. in 4% paraformaldehyde solution for 1 hour. . After washing 2-3 times with Phosphate-buffered saline (PBS) solution, the biofilms were fixed on gelatin-coated slides and finally dehydrated with ethanol dilutions (50, 80, 100%).

The oligonucleotide probe used in the experiments was synthesized by using the previously reported probe EUB338 for detecting bacteria and probe NSO1125 for detecting ammonia oxidative bacteria, and fluorescent labeling with fluorescein isothiocyanate (FITC) and hyrophilic sulfoindocyanine dye (CY3, CY5). (MWG Biotech, German).

Samples that had undergone the fixation and dehydration pretreatment were reacted with a hybridization buffer (0.9M NaCl, 20 mM Tris-HCl, 0.01% SDS) and a probe at 46 ° C for 90 minutes in a hybridization chamber. Probe concentration was kept constant at 25-50 ng / L. After the hybridization was rinsed lightly with pre-heated washing buffer (20mM Tris-HCl, 0.01% SDS) for 10 minutes at 48 ℃. After the reaction, the sample was lightly rinsed with distilled water to remove the washing buffer, air dried and treated with 25 μl of mounting medium.

Microorganisms were observed using a Zeiss Axiovert fluorescence microscope and an MRS-1024 (Bio-Rad, U.K.) confocal laser scanning microscope (CLSM) equipped with a Kr / Ar ion laser (Excitation wave length 494, 550, 650 nm).

Figure 2a is a FISH result of microorganisms attached to a porous polyvinyl acetal polymer foam carrier containing no activated carbon powder and zeolite powder, Figure 2b is a polyvinyl acetal coated with an adhesive 5% each activated carbon powder and zeolite powder FISH results of microorganisms attached to the polymeric foam carrier. In addition, Figure 2c is a FISH result photograph of the microorganism attached to the polyvinyl acetal polymer foam carrier foamed by mixing together 5% activated carbon powder and zeolite powder according to the present invention, selectively bound to all bacteria by probe EUB338 It is red and the microorganisms that oxidize ammonia by probe NSO1125 are yellow.

From the above results, it was found that the porous polyvinyl acetal polymer foam carrier without activated carbon powder and zeolite powder incubated 30 to 40% of all microorganisms compared to the carrier with 5% activated carbon powder and zeolite powder. , Ammonia oxidizing bacteria was found to be distributed in a very small number. In addition, in the case of porous polyvinyl acetal polymer foam carrier coated with 5% of activated carbon powder and zeolite powder, compared to polyvinyl acetal polymer foam carrier foamed by mixing 5% of activated carbon powder and zeolite powder together, Although the number was almost similar to more than 90%, as shown in Figure 2c, it was confirmed that the number of ammonia-oxidizing microorganisms is very small even with the naked eye.

<Example 4>

Removal experiments of volatile organic compounds (BTEXs) were carried out using a biofilter filled with a foamed polymer carrier according to the present invention. The microorganisms inoculated on the carrier for the experiment were three kinds of selectively cultured Pseudomonas sp., Which were classified by the microbiological identification classification system (MIDI). , substrates such as ethyl-benzene were used.

Resistance of BTEX Compound and Substrate Utilization Activity of Toluene and Ethyl-benzene microbe Resistance Substrate utilization activity Benzene Toluene Ethyl-benzene Xylene Toluene 100 ppm Toluene 1000 ppm Ethyl-Benzene 100 ppm Ethyl-Benzene 1000 ppm Pseudomonas sp. T4 - ++ ++ ++ <1 <35 <1 <35 Pseudomonas putida type A1. V6 - + + ++ <1 <35 <1 <35 Pseudomonas putida type A1. V16 - + + ++ <1 <35 <1 <35

+: Positive growth; ++: Positive high growth; -: Negative growth.

The experiments were carried out using a porous polyvinyl acetal polymer foam carrier without activated carbon powder and zeolite powder, polyvinyl acetal polymer foam carrier coated with 5% of activated carbon powder and zeolite powder, and activated carbon powder and zeolite powder, respectively. Each of the polyvinyl acetal polymer carriers mixed and foamed together by 5% was filled in a 5L biofilter with a working volume, and three kinds of Pseudomonas sp. Each culture was inoculated with 500 mL each.

In the experiment, toluene was used as a volatile organic compound, a syringe pump and an air pump were used to supply toluene at a constant rate to the reactor, and the biofilter was supplied in an upflow manner. Air injected with toluene controlled the residence time in the reactor through a control valve. Toluene was supplied to the biofilter at a concentration of 200 to 1,000 ppmv, and the tower residence time was maintained at 10 seconds.

Decomposition rate of toluene was measured by using GC (HP6890 series; Flame Ionization Detector) by installing gas collection pipes at the inlet and outlet of the biofilter. In addition, 1N NaOH solution, K ₂ HPO ₄ , and KH ₂ PO ₄ were administered to the nutrient medium to prevent the pH in the reactor caused by microbial respiration and toluene degradation.

Table 4 shows the removal rate according to the concentration of toluene, and each result is the average value of 20 days of operation results by concentration after the initial microbial stabilization period of 10 days. The most effective toluene removal rate was shown in the biofilter filled with polyvinyl acetal polymer carrier foamed by mixing the activated carbon powder and the zeolite powder, respectively, by 5%.

Average Toluene Removal Rate by Activated Carbon and Zeolite Powder Toluene concentration General PVA Carrier (Domestic Patent No. 346915) Activated Carbon 5% and Zeolite 5% Coated PVA Carrier 5% activated carbon and 5% zeolite mixed PVA carrier (invention) 200 ppmv 76% 95% 100% 500 ppmv 85% 92% 100% 800 ppmv 80% 88% 98% 1,000 ppmv 76% 82% 95%

As described and demonstrated in detail above, the porous polymer carrier foamed by mixing the activated carbon powder and the zeolite powder provided according to the present invention has a detachment phenomenon or micropore adhesive appearing in a conventional carrier coated on the surface of the activated carbon powder and zeolite powder. Problems such as clogging due to the above were improved.

In addition, the carrier of the present invention forms a very light and excellent hydrophilic and porous open cell structure, the specific surface area and excellent material transfer rate is excellent in mechanical strength and durability, physically, chemically and biologically stable, but also excellent physical properties Adsorption of microorganisms and contaminants provides excellent removal rate and stability. In addition, the biofilter filled with the carrier has a low pressure loss, and thus shows a high processing efficiency even in a short residence time, compared to conventional biofilters, requiring a narrow land area and a low initial investment cost, and reducing power costs.

Claims (7)

Method for producing a porous foam polymer carrier for biofilter comprising the following steps: (a) 5-9% by weight of any expandable polymer selected from the group consisting of polyvinyl acetal, polyurethane, polystyrene and polyethylene, 5-9% by weight of aldehyde compounds and 72-88% by weight of water, and then Mixing 10 wt% activated carbon powder and / or zeolite powder to obtain a first mixture; (b) mixing 1 to 30 parts by weight of starch and / or dextrin, which are soluble substances in the first mixture, based on 100 parts by weight of the first mixture, respectively, to obtain a second mixture; (c) heating the second mixture to 60-80 ° C. to melt it; (d) adding 10-30 parts by weight of the decomposable blowing agent and an acid with respect to 100 parts by weight of the second mixture to obtain a third mixture; (e) adding the third mixture to a mold and reacting at 50 to 80 ° C. to obtain a carrier in the form of a sponge foam or a nonwoven fabric; And (f) eluting off the starch and / or dextrin by washing the obtained carrier in the form of a sponge or nonwoven fabric. delete delete The method of claim 1, wherein the second mixture comprises at least one material selected from sodium alginate, carboxymethyl cellulose (CMC) and carboxymethyl starch (CMS) in addition to starch and / or dextrin, based on 100 parts by weight of the first mixture. 30 parts by weight of the method characterized by containing. delete The method of claim 1, wherein the mold is a hexahedron shape having a width, length, and height of 10 mm to 20 mm, or a circular model having a diameter of 10 mm to 20 mm. delete