KR20140097963A - A bioball comprising porous polyurethane foam media and device for wastewater treatment using the same and method for wastewater treatment using the same - Google Patents

Abstract

The present invention relates to a bioabs including a porous polyurethane foam carrier, and a method and apparatus for treating wastewater using the bioabsorbable material. In the fluidized biofilm reaction process for treating suspended solids including organic matters and nutrients in wastewater, Characterized by the use of a secure bio-ball with excellent porosity polyurethane carrier and fluidity and wear resistance of the carrier.

Description

Technical Field [0001] The present invention relates to a bio-ball containing a polyurethane foam carrier, and a device and a method for treating wastewater using the same.

The present invention relates to a bio-ball comprising a polyurethane foam carrier and an apparatus and a method for treating wastewater using the bio-ball, and more particularly, to a bio-ball comprising a porous carrier to which a micro- And more particularly to a method and apparatus for more efficiently treating wastewater containing a high concentration of organic substances and nutrients such as nitrogenous phosphorus.

As the use of various synthetic materials increases, various pollutants are present in wastewater, and it is difficult to decompose or treat these materials easily. In conventional wastewater treatment facilities, general biological treatment processes such as activated sludge process are used to treat organic substances and suspended substances.

However, water quality standards for effluent water in existing wastewater treatment plants have been strengthened, and it is becoming difficult to satisfy the emission allowance standards by treating only organic substances and suspended substances that are easily decomposed. In addition, due to the recent four major river projects, interest in the water quality of rivers has been increasing, and accordingly, standards for effluent water for maintaining and managing river water quality have been strengthened, and appropriate countermeasures are needed.

The activated sludge process applied to the conventional wastewater treatment is applied in a biological reactor by slowing the growth and reaction rate of the microorganisms and returning the effluent or the sludge in the process and recirculating them or attaching the microorganisms to the carrier so that they can stay for a long time . However, since the microbial adhesion efficiency of the carrier is low, treatment with the pollutants is not easy, and there is a disadvantage in that the specific gravity is lowered and the fluidity is lowered due to wear for a long period of time. Various studies have been carried out to increase the durability of the carrier and to increase the attachment efficiency of microorganisms, and various patents have been filed on the basis thereof.

Korean Patent Registration No. 0467062 discloses a carrier (density of 20 to 80 kg / kg) which is a polyurethane or a derivative thereof. However, since the conventional polyurethane foam carrier including the conventional technology has a specific gravity smaller than 1 and floats on water, There was a problem that it fell.

Korean Patent Application No. 1998-0040217 discloses a wastewater treatment method using a fluidized bed biofilm carrier in which a plurality of tubular pores are provided and a biofilm adheres to the inner surface of the tubular pores and nitrogen and phosphorus can be removed from the wastewater. / RTI > However, since the specific gravity is too low (0.96 or less), the fluidization can not be carried out in the aerobic tank, and it tends to drift toward the one side of the reactor due to drifting in the fluid flow. As a result, the inside of the small pores becomes clogged with solids, It is disadvantageous in that the diffusion efficiency of pollutants is low and the treatment efficiency is low.

Accordingly, the inventor of the present invention has been studying to improve the conventional carrier abrasion phenomenon and floating phenomenon, and it has been found that the wear of the carrier is prevented by filling a carrier in a ball cage to protect the carrier, The specific gravity was maintained, and the present invention was completed.

In order to solve the above problems, it is an object of the present invention to provide a cage capable of adhering and growing a microorganism in a carrier at a high concentration, preventing wear of the carrier and facilitating fluidity of the carrier. That is, it is intended to provide a bio-ball for filling a cage with a polyurethane foam carrier to improve its durability and fluidity, and to adhere and grow a high concentration of microorganisms on a carrier and to apply it to a biological treatment.

The present invention also provides a method and apparatus for treating wastewater with high efficiency compared to the conventional wastewater treatment process by treating suspended substances that have not been treated by a fluidized biofilm reactor through a filtration step including a fibrous filter medium.

In order to solve the above problems, the present invention provides a bio-ball for treating wastewater containing a polyurethane foam carrier having a specific gravity of 1.0 to 1.3 and a porous cage surrounding the polyurethane foam carrier.

The specific gravity of the bio-balls containing the polyurethane foam carrier is preferably 1.2 to 1.5.

If the specific gravity is 1.2 or less, it is difficult to efficiently treat the wastewater with an increase in floatability. If the specific gravity is more than 1.5, it is too heavy and the possibility of sinking in the wastewater is high and the fluidity is low.

Further, it is preferable that the cage is a sphere having a diameter of 16 mm to 75 mm. If the diameter of the cage is less than 16 mm, the specific gravity is low and the suspension floats inside the reactor. If the diameter is larger than 75 mm, the fluidity becomes too heavy, and the number of bio balls that can be filled in the reactor is limited. It is because it can go mad.

The cage may have any shape, but it is preferable that the polyurethane foam carrier supported on the inside of the cage is porous having a wide surface area so that it can contact with more wastewater.

Even if the specific gravity of the polyurethane foam carrier decreases through abrasion or the like through such a cage, an appropriate specific gravity can be maintained.

In addition, the polyurethane foam carrier preferably includes a surface-widening substance, a crosslinking agent and a specific gravity increasing substance.

The surface-widening material improves the microbial adhesion efficiency and improves the adsorption efficiency of the wastewater on organic and inorganic contaminants. Examples of the surface area enlarging material include activated carbon, char, ion exchange resin, natural clay, zeolite, and the like.

Further, the durability of the conventional polyurethane foam can be increased through the crosslinking agent.

It is also possible to provide a polyurethane foam carrier having proper floatability through a specific gravity increasing material.

According to another embodiment of the present invention, there is provided a wastewater treatment method using bio-balls for treating wastewater.

The method for treating wastewater comprises the steps of adjusting the pH of the wastewater (step 1); Removing the organic matter and the refractory material of the wastewater treated in the step 1 in a fluidized bed biofilm reactor filled with the first bio-ball (step 2); Removing the remaining organic matter and refractory material of the wastewater treated in the step 2 in a fluidized biofilm reactor filled with the second bio-ball (step 3); And filtering the wastewater treated in the step 3 (step 4).

The pH of step 1 is preferably 6.5 to 8.5.

Wherein the bio-ball for treating the wastewater includes a first bio-ball including a polyurethane foam carrier having an anaerobic microorganism attached thereto; And a second bio-ball comprising a polyurethane foam carrier having aerobic microorganisms attached thereto.

In the biofilm reactor filled with the bio-ball containing the carrier having the anaerobic microorganisms attached thereto in the step 2, the pH-controlled sewage or wastewater is treated to remove the high concentration of organic matter, nutrients and degradable pollutants contained in the influent water Disassemble.

In the step 3, the biofilm-loaded fluidized biofilm reactor containing the carrier to which the aerobic microorganism is attached removes the undegraded residual organics, nutrients and refractory pollutants of the wastewater treated in the step 2.

In step 4, the fibrous filter material may be used to perform filtration of residual suspended matter, organic matter, and nutrients.

In addition, the method for treating wastewater may further include a step of flocculating and precipitating wastewater according to the characteristics and concentration of the wastewater treated in the step 4 (step 5).

According to another embodiment of the present invention, there is provided a wastewater treatment apparatus including bio-balls for wastewater treatment.

The wastewater treatment apparatus includes a pretreatment tank for adjusting the pH of the wastewater; An anaerobic tank filled with the first bio-ball; And an aerobic reaction tank filled with the second bio-ball.

The apparatus also includes a first bio-ball comprising a polyurethane foam carrier having an anaerobic microorganism attached thereto; And a second bio-ball comprising a polyurethane foam carrier having aerobic microorganisms attached thereto.

In addition, a transfer pump for transferring the target treatment water in a fixed amount is preferably installed between the pretreatment tank and the anaerobic reaction tank, but is not limited thereto.

In addition, an air supply device for supplying air is installed at the lower end of the aerobic reaction tank, and there is a transfer pipe between each of the reactors, and the wastewater treated in each step is transferred to the next reaction tank.

Each reaction tank is packed with a bio-ball filled with a carrier having anaerobic and aerobic microorganisms attached thereto at a volume ratio of 20 to 30%, and it is possible to continuously stir the bio-ball with a stirrer to facilitate the flow inside the reactor. According to an embodiment of the present invention, the biofill filling rate of each reactor can be adjusted to at least 10% of the reactor volume.

It is also possible to provide a reaction tank in which a bio-ball and a polyurethane foam carrier are mixed by adding a micro-organism-attached polyurethane foam carrier for sufficient biological treatment efficiency.

Preferably, the wastewater treatment apparatus further includes a filtration tank made of a fibrous filter medium.

The wastewater treatment apparatus may further include an agglomeration and sedimentation tank for agglomerating the solid matter of the wastewater treated in the aerobic reaction tank.

It is needless to say that the processing apparatus and method using the bio-ball may be changed in the order of addition or treatment of the anaerobic tank and aerobic tank depending on the characteristics of sewage or wastewater.

Further, in the present invention, it is possible to reduce the occurrence of surplus sludge by using a fluidized bed biofilm reactor, while in the case of pre-treatment of a biological treatment process of existing sewage or wastewater or further treatment of excess sludge in effluent water, The amount of the sludge finally to be treated can also be reduced.

In addition, it is possible to shorten the residence time in the reaction tank for the treatment of sewage or wastewater, thereby providing a very economical and efficient treatment result .

According to an embodiment of the present invention, as the carrier is supported in the cage, the fluidity and abrasion of the carrier are improved, and stable operation for a long period of time is possible.

Also, since the microorganisms are stably attached to the carrier and maintained at a high concentration, the treatment efficiency of the wastewater is improved, and the concentration of the suspended microorganisms in the effluent is reduced, thereby extending the life of the filter used in the effluent filtration.

Also, according to the embodiment of the present invention, microorganisms can be attached to the cage so that microorganisms can be maintained at a high concentration, and efficient and stable wastewater treatment can be performed in the fluidized bed biofilm reactor together with the carrier.

FIG. 1A is a polyurethane foam carrier for wastewater treatment according to an embodiment of the present invention, and FIG. 1B is a cage according to an embodiment of the present invention.
2 is an experimental photograph comparing the specific gravity and fluidity of a polyurethane foam carrier according to an embodiment of the present invention and a bio-ball containing the same.
3 is a fibrous filter material made of polypropylene according to an embodiment of the present invention.
FIG. 4A is a process chart of a wastewater treatment using bioball, and FIG. 4B is a process chart of a wastewater treatment process in which a coagulation step is added.
5 is a batch test result of sewage treatment using a polyurethane foam according to an embodiment of the present invention.
FIG. 6 is a batch test result of sewage treatment using a bioball according to an embodiment of the present invention.
FIG. 7 shows results of sewage treatment for a long-term operation using a biofilm-supported fluidized biofilm treatment apparatus according to an embodiment of the present invention.
8 is a result of wastewater treatment for a long period of operation using a biofilm-supported fluidized biofilm treatment apparatus according to an embodiment of the present invention.
Fig. 9 shows the result of sewage treatment using a fibrous filter material.

Hereinafter, the present invention will be described in more detail with reference to Examples, but it goes without saying that the present invention is not limited to these Examples.

Example  One

100 g of a polyurethane prepolymer, 5 g of an adsorbent, 10 g of a crosslinking agent and 4.5 g of a specific gravity adjusting agent were mixed and polyurethane foam was foamed with 3 g of a nonionic surfactant to prepare a polyurethane foam carrier. The polyurethane prepolymer used was Hypol-3000 (Dow Chemical CO.). Activated carbon was used as the adsorbent, hemitite was used as the specific gravity adjusting agent, and triethanolamine was used as the crosslinking agent. The specific gravity of the carrier thus prepared was 1.05.

Experimental Example  One : Bio-ball  Specific gravity and fluidity confirmation experiment

Experiments were carried out as follows to examine the specific gravity and fluidity of the bio-balls containing the polyurethane foam carrier prepared according to the examples.

Specifically, the polyurethane foam carrier prepared in Example 1 and the plastic balls containing the polyurethane foam carrier were each filled with an appropriate amount of 1 L beaker, and then the specific gravity and fluidity thereof were observed.

Referring to FIG. 2 (a), it was confirmed that the polyurethane foam carrier and the bio-ball float on the surface, and the specific gravity is close to 1. However, referring to FIGS. 2 (b) and 2 (c), when the polyurethane foam carrier having microorganisms attached to the bio-ball was filled, the specific gravity was increased.

Experimental Example  2: Suspension concentration measurement experiment

Experiments were carried out as follows to confirm the adsorption performance of suspensions of bio-balls containing the polyurethane foam carrier prepared according to the examples.

More specifically, the polyurethane foam carrier prepared according to the examples was cut into squares of 1 x 1 x 1 cm and the activated sludge was stably attached for 2 weeks to analyze the biomass. In addition, the polyurethane foam carrier according to the examples was filled in a plastic ball, and the activated sludge was stably attached for 2 weeks in the same manner as the polyurethane foam carrier, and the biomass was analyzed.

As a result, as shown in Table 1, the biomass concentration of the polyurethane foam carrier was 0.001 (g / g) and the MLSS was 2,600 (mg / L). In addition, the bioball containing the polyurethane foam carrier had an average concentration of 0.22 (g / g) of biomass and an average of 5,500 (mg / L) of MLSS.

In the case of bioball, it was confirmed that the MLSS was more than 2 times higher than that in the case of using only the polyurethane foam carrier.

Polyurethane foam carrier Bioball Biomass (g) 0.002 0.001 0.001 0.212 0.228 0.221 Carrier weight (g) 0.072 0.074 0.087 0.084 0.091 0.088 Plastic ball weight (g) 7.252 7.308 7.229 MLSS (mg / L) 3,000 2,400 2,600 5,300 5,700 5,500

Experimental Example  3: Bio-ball COD  And nutrient removal efficiency experiment

To investigate the COD and nutrient removal efficiency of bioballs, the following experiment was conducted.

Specifically. COD and nutrient removal efficiencies of sewage water were measured for the polyurethane foam carrier prepared in the examples, the polyurethane foam carrier having the microorganisms attached thereto and the bio-ball.

FIG. 5 shows the result of the sewage treatment experiment using the polyurethane foam carrier with the anaerobic and aerobic microorganisms attached thereto, and FIG. 6 shows the results of the sewage treatment experiment using the bio-ball containing the polyurethane foam carrier with the anaerobic and aerobic microorganisms.

As can be seen from Figs. 5 and 6, it was found that the sewage treatment using BioBall was much more efficient than the treatment using the conventional polyurethane foam carrier.

FIG. 7 shows results of long-term experiments on sewage treatment using bio-ball, and FIG. 8 shows results of long-term experiments on wastewater treatment using bio-ball. As can be seen from FIGS. 7 and 8, when the bio-ball is treated with sewage and wastewater, the treatment results of COD are close to that of effluent water for about 30 days. In the case of nutrient salts (TN, TP) Can be confirmed.

Experimental Example  4: Suspended matter analysis experiment

Experiments were conducted to confirm the treatment of suspended solids in a treatment apparatus that further includes bio-ball wastewater treatment and fibrous filter media.

Specifically, a treatment apparatus using a bio-ball containing a polyurethane foam carrier with anaerobic and aerobic microorganisms attached thereto was operated for a long period of time to check whether sewage or wastewater treatment was performed.

In addition, suspended solids in the effluent are analyzed by using a treating apparatus using a fibrous filter medium, and they are shown in Fig.

When the suspended solids in the effluent were filtered using fibrous filter media, the concentration of SS was 2 mg / L, confirming that it was 10 mg / L, which is the effluent standard of the sewage treatment plant.

100: Bio Bowl
200: fibrous filter media

Claims (9)

A polyurethane foam carrier having a specific gravity of 1.0 to 1.3; And
A method for treating wastewater using a bio-ball for treating wastewater comprising a porous cage surrounding the polyurethane foam carrier,
The bio-ball for treating wastewater,
A first bio-ball comprising a polyurethane foam carrier with an anaerobic microorganism attached thereto; And
And a second bio-ball comprising a polyurethane foam carrier having aerobic microorganisms attached thereto,
The method for treating wastewater,
Adjusting the pH of the wastewater (step 1);
Removing the organic matter and the refractory material of the wastewater treated in the step 1 in a fluidized bed biofilm reactor filled with the first bio-ball (step 2);
Removing the remaining organic matter and refractory material of the wastewater treated in the step 2 in a fluidized biofilm reactor filled with the second bio-ball (step 3);
Filtering the wastewater treated in the step 3 (step 4); And
(Step 5) of coagulating and precipitating the wastewater treated in step 4 above.
Wastewater treatment method.
The method of claim 1, wherein the cage is a sphere having a diameter of 16 mm to 75 mm.
The method of claim 1, wherein the specific gravity of the bio-ball is 1.2 to 1.5.
The method of claim 1, wherein the polyurethane foam carrier comprises a surface-widening substance, a crosslinking agent, and a specific gravity-increasing substance.
[4] The method according to claim 1, wherein the step 4 is filtration of residual suspended matter, organic matter, and nutrients using a fibrous filter material.
A polyurethane foam carrier having a specific gravity of 1.0 to 1.3; And
And a bio-ball for treating wastewater containing a porous cage surrounding the polyurethane foam carrier,
The bio-ball for treating wastewater,
A first bio-ball comprising a polyurethane foam carrier with an anaerobic microorganism attached thereto; And
And a second bio-ball comprising a polyurethane foam carrier having aerobic microorganisms attached thereto,
The wastewater treatment apparatus includes:
A pretreatment tank for adjusting the pH of the wastewater;
An anaerobic tank filled with the first bio-ball;
An aerobic reaction tank filled with the second bio-ball;
A filtration tank made of a fibrous filter medium; And
And a flocculation and settling tank for flocculating the solid matter of the wastewater treated in the aerobic tank.
Wastewater treatment device.
2. The wastewater treatment device according to claim 1, wherein the cage is a sphere having a diameter of 16 mm to 75 mm.
The wastewater treatment device according to claim 1, wherein the bio-ball has a specific gravity of 1.2 to 1.5.
The wastewater treatment device according to claim 1, wherein the polyurethane foam carrier comprises a surface widening substance, a crosslinking agent and a specific gravity increasing substance.

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