KR19990073118A - Microbial media unit for biological wastewater treatment - Google Patents

Abstract

The present invention relates to a microorganism carrier unit for wastewater / wastewater treatment.

Inside the frame box with mesh structure to allow the waste water to pass through

After filling the microorganism carrier with the specific gravity adjusted to 5 to 70% by volume for the fixed bed and 30 to 90% by volume for the fluidized bed, cover the lid of the network structure,

Provided is a microbial carrier unit provided with a fixed bed carrier unit prepared in this way in an anaerobic or aeration tank at 50 to 100% by volume, or in a fluid tank at 30 to 70% by volume.

According to the present invention, by filling an appropriate amount of a suitable carrier unit in a mold which can easily contain carrier particles and penetrate the wastewater / wastewater therein, the dispersibility of the active carrier can be improved, and the flow channel of the wastewater can be formed so that sludge can be formed. The clogging phenomenon can be improved.

Description

Microbial carrier unit for sewage / wastewater treatment {MICROBIAL MEDIA UNIT FOR BIOLOGICAL WASTEWATER TREATMENT}

The present invention relates to a microbial carrier unit for wastewater / wastewater treatment. More specifically, the present invention relates to a microbial carrier unit for effectively treating wastewater / waste water in both anaerobic and aeration tanks by filling an appropriate amount of microbial carriers in a mold.

Biological wastewater treatment methods can be largely divided into activated sludge process and biofilm process. In the case of wastewater treatment by activated sludge method, there are problems such as low coping capacity against load fluctuations and a lot of surplus sludge.

On the other hand, in the biofilm process in which microbial contactants that attach and multiply microorganisms are installed in wastewater / wastewater treatment facilities to decompose and treat contaminants by proliferating microorganisms, microorganisms are adhered to the carrier at high concentrations to cause swelling of sludge. It can be prevented, and the removal efficiency is good even at high / low concentration load, the amount of sludge generated and sludge transportation is unnecessary, so it is economical in terms of facility cost and power, and the reactor size is small. There is this.

In general, various carriers are used to attach microorganisms in wastewater / wastewater treatment processes using biofilms. The material is divided into polymer, ceramic, or activated carbon, and the shape may be in various forms such as spherical or tube-shaped and fibrous or non-woven fabrics.

Polymeric carriers are easy to manufacture in a desired shape and are inexpensive, but have a small specific surface area and are physically / chemically unstable, causing frequent desorption of microorganisms and a large amount of sludge generation.

On the other hand, activated carbon or ceramic carriers have the advantages of large specific surface area, physical / chemical stability, thin microbial film formation, and low sludge generation rate, but are usually formed into fine particles of about 2 to 10 mm and difficult to directly enter into the reactor. The disadvantage is that it cannot be used with a cursor fluidized bed.

In order to use the microorganism immobilization carrier used in the biofilm process in an anaerobic tank or aeration tank, a different method is required depending on the reactor. The anaerobic tank is generally a layer flow that is difficult to mix liquids by internal and external mixing devices to prevent the incorporation of air, and liquid flow and turbulence formation are not formed. It is good to stay constant.

For this reason, there are many examples in which a fiber-like or non-woven carrier is manufactured in a plate shape and installed and installed in a reactor (parallel passage reactor), which is installed at regular intervals inside the reactor.

On the contrary, the granular carrier made of activated carbon or clay mineral is filled in a large thin plate-shaped rectangular parallelepiped wire mesh box due to its limitation in shape, and then placed in parallel in the form of PPR by placing the wire mesh box in parallel. Dispersion efficiency in the reactor is inferior and the width of the wire mesh box filling the carrier cannot be reduced, so that the distance between the wire mesh boxes is shortened in order to lower the volume share of the carrier in the reactor, and thus the overall efficiency decreases due to the slow speed of mass transfer between the fluid and the carrier. There is this.

In addition, in the aeration tank, care must be taken not to lean the carrier to one side or to exhibit aeration resistance for smooth aeration, and the dispersibility and surface area of the carrier should be reduced while improving the treatment efficiency. For this reason, the fluidized bed carrier is preferred to the fixed bed carrier in the aeration tank, but there has been no fluidized bed carrier which can be manufactured in good performance and cheaply.

Therefore, in order to overcome this disadvantage, Korean Patent Publication No. 96-9384 is a fluidized bed capable of adjusting the specific gravity by inserting and fixing a specific gravity control object in a cage-shaped fluidized bed unit made of plastic and inserting a scrubber-like fibrous carrier. The microbial contact unit has been proposed, but in this case, it is a synthetic scrubber-like microbial contactant, which is disadvantageous in that microorganisms are not friendly, physical / chemically unstable, and difficult to manufacture structurally compared to activated carbon or clay-based carriers. have.

In addition, the Republic of Korea Patent Publication No. 98-33594 proposes a fluidized bed microbial contact agent using a polymer fiber yarn, but because the polymer is a problem such as desorption of microorganisms, and the specific gravity is close to water Since small fibers are the main component, there is a disadvantage in that they float on water when the flow is weak or there is no aeration.

Separately, Korean Patent Publication No. 97-26944 discloses a fluidizing carrier using a spherical porous glass carrier instead of a polymer, and using a foamed styrene rod at the inner center and a porous glass carrier having a freeze-dried strain attached thereto. It is not easy to manufacture because it must be wrapped in a net, it is made of a foamed styrene rod is blocked inside the unit has a disadvantage that the flow of fluid does not flow smoothly through the inside.

In addition, Korean Patent No. 97-42320 proposes a fluidized bed carrier unit wrapped with a spherical activated carbon and expanded styrene in a wire mesh, but the scope of use by grafting a special strain is limited and the spherical carriers are wrapped in a wire mesh and fixed to each other. As a result, the flow rate into the carrier unit is not good and the manufacturing process of wrapping the wire mesh is inconvenient, causing problems in mass production.

Accordingly, an object of the present invention, in order to overcome the above problems, by applying a network structure to prepare a mold penetrating the waste water / wastewater inside, and filling the carrier particles with a specific gravity controlled therein to prepare a carrier unit, then The present invention is to provide a microbial carrier unit that effectively treats biological wastewater by applying an effective amount to an anaerobic tank and an aeration tank, respectively.

Figure 1 (a) is a three-dimensional view showing the box and lid of the cylindrical frame made of a material such as iron, stainless steel (SUS), plastic of the network structure,

Figure 1 (b) is a three-dimensional view showing a mold in the form of a cube made of the material used in 1 (a),

Figure 1 (c) is a three-dimensional view showing a space divider (space divider) inside the form box divided into several rooms,

Figure 1 (d) is a three-dimensional view showing the mold in the form of a clay or clay-activated carbon composite material in the form of a tube and covered with a lid of the network structure,

Figure 2 (a) is a cross-sectional view showing a particulate microbial carrier prepared by molding and firing activated carbon, clay or a mixture thereof using an adhesive,

Figure 2 (b) is a cross-sectional view showing a particulate microbial carrier for controlling specific gravity by coating activated carbon, clay or a mixture thereof on the foamed plastic,

2 (c) is a cross-sectional view showing the foamed plastic particles,

FIG. 3 is a stereoscopic view showing a final carrier unit in which the carrier / particles of FIGS. 2 (a) to 2 (c) are filled in the frame box of the network structure of FIG. 1 (a).

* Description of the simple signs in the drawings *

A ... mold box for filling microbial carriers

B ... Lid C ... Space divider

According to the invention,

Inside the frame box with mesh structure to allow the waste water to pass through

After filling the microorganism carrier with the specific gravity adjusted to 5 to 70% by volume for the fixed bed and 30 to 90% by volume for the fluidized bed, cover the lid of the network structure,

Provided is a microbial carrier unit provided with a fixed bed carrier unit prepared in this way in an anaerobic or aeration tank at 50 to 100% by volume, or in a fluid tank at 30 to 70% by volume.

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

The mold having a network structure of the present invention comprises a mold box (A) and a lid (B) to contain an active carrier.

At this time, the mold is formed by processing a hard material such as iron, stainless steel, plastic, or a cylindrical or polygonal tube shape with an open top (see FIGS. 1 (a) and 1 (b)), or by forming an active ingredient or other hard material into a tube shape. After the form box is manufactured, it is made into a meshed top and a capped form (see Fig. 1 (d)).

Then, the mold is partially filled with a microbial carrier having a specific gravity.

As the microbial carrier to be filled in the mold box, the specific gravity is higher than that of water by coating a clay or clay-activated carbon composite material (hereinafter referred to as 'active ingredient') with a buoyant body using an appropriate adhesive on the surface of the buoyant body. Lightened carriers (hereinafter referred to as 'active coating carriers') and / or (ii) carriers in which the active ingredient is molded in the form of particles (hereinafter referred to as 'active carriers') can be mixedly used.

The buoyant body may be foamed plastic, styrofoam, wood with a specific gravity lower than water, and hollow plastic balls.

The active coating carrier is sprayed with an aqueous solution or an organic solution slurry of the active ingredient, an adhesive and an optional pore control agent on a buoyant body having a specific gravity of 2 to 10 mm lower than that of water, and then fired at 300 ° C. or less to have a specific gravity less than 1. Prepare a coating active carrier form (see Figure 2 (b)).

When firing at 300 ° C. or higher, a part of the buoyancy body may be decomposed at high temperature firing, which is not preferable.

The active coating carrier has a diameter of 2 to 20 mm, more preferably 3 to 10 mm. If it is out of the above range, the specific surface area obtained is not suitable compared to the amount used, which is not preferable.

In addition, it is preferable that the size ratio of the active carrier and the unit having such a diameter is in the range of 1: 4 to 1:40, more preferably in the range of 1:10 to 1:25. It is good to adjust. Beyond this range, not only is it uneconomical, but improved reaction efficiency cannot be obtained when manufacturing the unit during manufacture and subsequent installation in the application.

At this time, the active ingredients used are zeolite, clays (ongyo clay, clay clay, kaolin, diatomaceous earth, vermiculite, talc, loess, etc.), steel mill waste slag, volcanic ash, combustion materials, etc. alone or in combination of two or more activated carbon It can be added and used further. At this time, when activated carbon is used, the addition amount is preferably 10 to 30% by weight.

As the adhesive, an organic or inorganic adhesive may be used, among which an organic adhesive may be polyvinyl alcohol, polyurethane, epoxy, acrylic resin, and the like, and an inorganic adhesive may be alumina sol, silica sol, water glass, cement, or the like.

The active ingredients are preferably mixed with an organic or inorganic adhesive in a weight ratio of 60 to 90:40 to 10. If the amount of adhesive added is less than 10%, some materials will be released from the water, and if it exceeds 40%, it will not be suitable because it adversely affects the adsorption capacity of the carrier or the ability of microbial adhesion.

It is preferable to optionally mix the pore regulator with the mixture thus prepared. The pore control agents that can be used are inorganic dyes such as ammonium carbonate and ammonium nitrate or organic high molecular materials such as ethylene glycol, cellulose and starch, and it is preferable to use them in an amount of 10% by weight or less based on the total weight of the active ingredient and the adhesive. . If it is out of the above range, it is poor in terms of strength and inadequate in terms of economy.

The coating thickness of the active coating carrier prepared as described above is to be adjusted according to the desired specific gravity, and depends on the level of the anaerobic tank or aeration tank to be used, but generally 5 mm or less is sufficient.

In addition to this, an active carrier may be used as a microbial carrier, instead of the active coating carrier, mixed with a buoyant body, which may be molded into particles and baked at 500 ° C. or lower at low temperature to form a spherical or other shape having a diameter of 2 to 20 mm. It is made of particles of (see Fig. 2 (a)).

The diameter of the prepared active carrier is preferably 2 to 20 mm, more preferably 3 to 10 mm, similarly to the active coating carrier.

In addition, when the firing temperature is 500 ° C or higher, the adhesive force is lost, which is not preferable.

As shown in FIG. 3, the microbial carrier thus prepared is filled with 5 to 70% by volume for the fixed bed and 30 to 90% by volume for the fluidized bed, and then the lid is made of a network structure to complete the carrier unit. .

For the stationary phase, it is preferable to fill the prepared microbial carrier with 5 to 70%, more preferably 10 to 40% of the volume of the carrier unit. Deviation from the above range is undesirable in terms of diffusion, specific gravity and performance.

In addition, for the fluidized bed, it is preferable to fill the prepared microbial carrier with 30 to 90%, more preferably 50 to 70% of the volume of the carrier unit. Outside the above range is not preferable in terms of efficiency and performance.

The carrier unit thus manufactured is installed in an anaerobic tank or aeration tank to be used without an auxiliary facility for installation within an appropriate volume range and used for a wastewater treatment process.

Specifically, the fixed phase carrier unit is administered in an anaerobic or aeration tank with 50 to 100% by volume of the liquid volume of the part where the waste water is immersed. Outside of the above range, it is not preferable in terms of efficiency and performance.

In addition, when the fluidized bed carrier unit is used in the aeration tank, it is administered at 30 to 70% by volume based on the volume of the aeration tank. In the case of the aeration tank, the flow due to bubbling is strong, and thus, when using the fluidized bed carrier unit, a smaller amount may be administered than when the fixed bed carrier unit is used.

In addition, by adding a space dividing element inside the mold, each room is divided into several rooms such that the size of the room is 30 to 1000 cm ³ , and the carrier is divided into small portions and filled so as to spread evenly in the reaction tank (see FIG. 1 (c)).

Example

Hereinafter, the present invention will be described in more detail with respect to the present invention.

<Example 1>

The same composition is used for the active carrier for filling (φ5mm × ℓ5mm) and polystyrene, which are fired at 150 ° C by mixing 60 wt% zeolite, 20 wt% activated carbon and 20 wt% polyurethane resin in a square plastic unit having a size of 5 cm × 5 cm × 5 cm. Filled coated carrier to 3: 1 volume ratio, 50 volume% based on unit volume, and then 70% by volume of carrier unit in 5 liter aeration tank to remove COD and NH ₄ ⁺ -N. Was measured.

Wastewater (C _in 200ppm) was introduced into the aeration tank and treated, and the COD removal efficiency was 98%, and the NH ₄ ⁺ -N removal efficiency was 93% for the wastewater (C _in = 30ppm).

<Example 2>

An active carrier was prepared under the same conditions as in Example 1 except that 10% by weight of ammonium nitrate was added. Experiments under the same conditions as in Example 1 showed that the COD removal efficiency was 98% and the NH ₄ ⁺ -N removal efficiency was 95%.

<Example 3>

A carrier unit was prepared in the same manner as in Example 1, except that a rectangular SUS unit having a size of 5 cm × 5 cm × 5 cm was used, and an active coating carrier was added about twice as much as the low temperature calcined carrier, and then Example 1 We went through the same experiment as in COD removal was 97% and NH ₄ ⁺ -N removal efficiency was 93%.

<Example 4>

A carrier unit having a specific gravity of 1-1.3 was prepared by coating a styrofoam (Kumho Chemical Co., Ltd.) having a diameter of 2 mm four times so as to have a coating thickness of 1.5 mm at the same composition ratio as in Example 3. The waste water treatment was carried out in the 2 L aeration tank under the same conditions as in Example 3, and the COD removal rate was 96% and the NH ₄ ⁺ -N removal efficiency was 87%.

Example 5

Example 2 was administered the carrier unit by 70% by volume of the carrier unit to the anaerobic tank 5ℓ prepared in result, the denitration efficiency of _{84% (C in, NO 3} - = 30ppm) was.

Comparative Example 1

As a result of performing the same experiment as in the above example with SARAN ROCK (Kureha Chemical Co., Ltd.), which is conventionally used as a fixing carrier in an aeration tank and an anaerobic tank, the COD removal rate was 91% and NH ₄ ⁺ -N removal. The efficiency was 76% and the denitrification efficiency (in the anaerobic tank) was 72%.

Advantages of the microbial carrier unit produced by the production method of the present invention are as follows.

(1) Since the carrier unit produced by the method of the present invention is composed of activated carbon and clay mineral or mixture thereof, the thickness of the microbial membrane is thinner, there is no problem of detachment, the specific surface area is wide, and the physical / Chemically stable, excellent in removing pollutants and semi-permanent.

(2) In addition, the active carrier to be filled in the mold has a small size, so that the outer surface area and the specific gravity can be adjusted to a desired value, which is particularly advantageous for producing a fluidized bed carrier unit. Therefore, the specific gravity of the carrier unit in the aeration tank is so low that it floats to the water surface or the gravity is too high so that the internal circulation is smooth and the inside of the carrier unit is not completely filled. As the flow into the unit is active, the mixing between the carrier and the waste water is increased, thereby increasing the treatment efficiency.

(3) In the anaerobic tank, the empty inner space and the outer space between the carrier units formed by dropping the carrier units form a channel of a certain size to facilitate the flow of fluid, thereby preventing the formation of a flow path due to the deposition of sludge generated. To prevent.

(4) The size of the inner space channel can be adjusted according to the amount of carrier in the unit, and the channel generated in the inner and outer space is formed in a curved form due to the free drop in the anaerobic tank of the carrier unit, which naturally adds the turbulence effect of the fluid.

(5) In addition, there is an advantage that the carrier can be evenly dispersed throughout the anaerobic tank while maintaining the volume ratio occupied by the carrier in the anaerobic tank to increase the residence time of the liquid in the reactor.

According to the above, by filling an appropriate amount of a suitable carrier unit in the mold prepared to easily contain the carrier particles and penetrate the waste water / waste water therein, it is possible to improve the dispersibility of the active carrier and to form a flow channel of the waste water, thereby allowing sludge The clogging phenomenon can be improved.

Claims (9)

Inside the frame box with mesh structure to allow the waste water to pass through After filling the microorganism carrier with the specific gravity adjusted to 5 to 70% by volume for the fixed bed and 30 to 90% by volume for the fluidized bed, cover the lid of the network structure, The microbial carrier unit having the fixed bed carrier unit thus prepared is installed at an anaerobic tank or aeration tank at 50 to 100% by volume or the fluidized bed carrier unit is installed at an aeration tank at 30 to 70% by volume. The method of claim 1, wherein the mold is formed into a net shape of iron, stainless steel, or plastic, or activated carbon, clay, or a mixture thereof is formed into a tube by using an adhesive, and a network lid made of the material is formed on top thereof. Units characterized by being overlaid The microorganism carrier of claim 1, wherein the microbial carrier to be filled in the (A) buoyancy body (Iii) mixing the active component selected from the group consisting of activated carbon, clay or mixture thereof on the surface of the buoyant body with a weight ratio of 60 to 90: 10 to 40 with an organic or inorganic adhesive so that the coating thickness is 5 mm or less; An active coating carrier coated and adjusted to a specific gravity lower than water, and / or (Ii) a unit which is prepared by molding the active ingredient of (iii) in the form of particles and mixing the active carrier prepared by baking at a low temperature below 500 ° C. The unit according to claim 2 or 3, wherein the adhesive is selected from the group consisting of polyvinyl alcohol, polyurethane, epoxy, acrylic resin, alumina sol, silica sol, water glass, cement. The method of claim 4, wherein the active coating carrier or the active carrier has a diameter of 2 to 20 mm. 6. The method of claim 5, wherein the active coated carrier or the active carrier has a diameter of 3 to 10 mm. The method of claim 1, wherein the fixed bed carrier is characterized in that the microbial carrier is filled with 10 to 40% based on the volume of the carrier unit. The method of claim 1, wherein the fluidized bed carrier is characterized in that the microbial carrier is filled by 50 to 70% based on the volume of the carrier unit. The method of claim 1, further comprising adding a space divider in the unit to fill the carrier to create multiple rooms.