JP2008168204A - Sewage treatment method and sponge carrier used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the rising time of a sewage treatment apparatus and system by promptly making a sponge carrier supplied into an aeration tank compatible with sewage, and absorbing water into the carrier to make the carrier floatable in the aeration tank; to make the treatment capacity of the sponge carrier high even at the rise time by fully exhibiting its function immediately after its supply; to maintain the treatment capacity at a high level even when replacing the carrier. <P>SOLUTION: In a treatment system for treating organic sewage using the activated sludge process, a sponge carrier impregnated with a hydrophilicity improving agent, microorganisms, and nutritive ingredients is used when another sponge carrier for supporting microorganisms is newly supplied to the aeration tank. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an activated sludge treatment method for organic sewage using a sponge carrier and its sponge carrier, and more particularly to a sewage treatment method for treating a sponge carrier to be fed into an aeration tank and its sponge carrier.

  Conventionally, in an activated sludge treatment method for organic sewage such as sewage, wastewater, human waste, etc., organic sludge is mixed with aerated sludge in an aeration tank, then aerated, and then sludge is separated in a solid-liquid separation tank. Is discharged as treated water, part of the separated sludge is returned to the aeration tank as return sludge, and the remaining sludge is discharged as excess sludge.

  Further, a batch type activated sludge treatment method in which aeration, separation, and the like are performed in one tank is used instead of a facility having a plurality of tanks as described above. In addition, since the tank used by this batch type is also provided with the aeration apparatus comprised by a blower, a diffuser tube, etc., the tank used by a batch type is also contained in the aeration tank demonstrated below.

  The aeration tank is loaded with microorganisms that decompose organic matter, nutrients for propagating the microorganisms, and a carrier that holds the microorganisms, and the carrier to which the microorganisms are attached flows in the tank. By treating the sewage, the microorganisms are kept at a high concentration in the aeration tank, thereby enabling a high load treatment of the sewage (see, for example, Patent Document 1).

  The carrier for adhering such microorganisms is not particularly limited as long as it is porous. Natural materials such as ceramic, silica gel, zeolite, and glass beads, natural polymers such as cellulose and sponge, and synthetic polymers such as polyurethane and polystyrene. Etc. are used.

  However, in general, inorganic carriers such as ceramics have a good initial familiarity with sewage, but have a large specific gravity and are easy to settle. There is also a problem that the carrier concentration in the aeration tank is biased and the processing capacity is lowered. Natural polymers also have disadvantages such as high cost.

  Therefore, when it contains water, it has the same specific gravity as water, it is easy to flow, that is, the specific gravity is small, the carrier concentration in the aeration tank is not easily biased, easy to handle, and inexpensive synthetic polymer. Synthetic sponges are often used. A synthetic polymer carrier in which a polyether urethane foam is formed into a sponge-like piece has also been proposed (see, for example, Patent Document 2).

JP 2002-86175 A JP 2000-279983 A

  However, when such a sponge is used as a carrier, when the new sponge carrier is introduced into the aeration tank at the time of starting up the sewage treatment apparatus / facility or replacing the sponge carrier, the sponge carrier is familiar with the sewage. It is bad, that is, its water absorption is low, so if it is just added, it will not absorb water at all and will float on the surface of sewage, and other carriers will be laminated on the floated carrier and will not come into contact with sewage at all. However, depending on the size of the aeration tank and the amount of carrier to be introduced, almost all of the introduced carriers absorb water, It takes several hours to several tens of days to flow, and during that time it does not play a role as a microbial carrier at all, and the treatment capacity of the sewage treatment equipment / facility becomes extremely low or decreases, and it takes a long time to start up. In short, that There is a problem that can not perform stable processing.

  Therefore, the present invention eliminates the drawbacks of the prior art and allows the sponge carrier to be put into the aeration tank to quickly become familiar with the sewage, absorb the water, and flow inside the aeration tank, thereby starting up the sewage treatment apparatus / facility. The purpose is to shorten the time, to fully demonstrate its functions immediately after the sponge carrier is charged, to keep the processing capacity high even at startup, and to keep the processing capacity high even when the carrier is replaced. .

  The present invention as a means for solving the above problems is to apply and impregnate a sponge carrier with a hydrophilicity improver for improving the hydrophilicity of the sponge carrier. It is intended to carry the microorganisms to be decomposed and the nutrients of these microorganisms.

  Specifically, in a facility for treating organic sewage using an activated sludge method, a sponge carrier for retaining microorganisms, which is introduced into an aeration tank, and is characterized by being impregnated with a hydrophilicity improver. Sponge carrier.

  Further, the sponge carrier is a sponge carrier in which microorganisms and / or nutrient components are supported.

  In addition, in a facility for treating organic sewage using the activated sludge method, a sponge carrier impregnated with a hydrophilicity improver is used in a new introduction of a sponge carrier for holding microorganisms into an aeration tank. This is a wastewater treatment method.

  The sponge carrier is a sewage treatment method in which a hydrophilicity improver is impregnated in advance before the sponge carrier is newly introduced into the aeration tank.

  The sponge carrier is a sewage treatment method characterized by impregnating a hydrophilicity improver in an aeration tank.

  Further, the present invention is a sewage treatment method characterized in that microorganisms and / or nutrient components are supported in advance on the sponge carrier before new introduction into an aeration tank.

  According to the present invention as described above, in the facility for treating organic sewage using the activated sludge method, the sponge carrier for retaining microorganisms was impregnated with the hydrophilicity improver in the aeration tank. The sponge carrier to be put into the aeration tank can be quickly mixed with sewage, absorbed, and flowable in the aeration tank, shortening the start-up time of the sewage treatment equipment / facility, and the function immediately after the sponge carrier is put in It has become possible to make the processing capacity high even at the time of start-up, and to maintain the high processing capacity even when the carrier is replaced.

  Furthermore, since microorganisms and / or nutrient components are supported on the sponge carrier, there is no waiting period until the microorganisms adhere to the sponge carrier in the aeration tank, and the startup time of the sewage treatment apparatus / facility is more efficient. It has become possible to fully demonstrate its functions immediately after the sponge carrier is charged, to maintain a high processing capacity even at startup, and to maintain a high processing capacity even when replacing the carrier. . In particular, by supporting nutrients, microorganisms can be efficiently propagated, and the above-described effects can be further enhanced.

  In addition, in a facility for treating organic sewage using the activated sludge method, since a sponge carrier impregnated with a hydrophilicity improver was used in the introduction of a sponge carrier to retain microorganisms into an aeration tank, aeration The sponge carrier to be put into the tank can be quickly mixed with sewage, absorbed, and allowed to flow in the aeration tank, shortening the start-up time of the sewage treatment device / facility, and the function immediately after the sponge carrier is put in. It was made possible to fully demonstrate it, and it was possible to keep the processing capacity high even at the time of start-up, and to keep the processing capacity high even when the carrier was replaced.

  Further, in the above method, the sponge carrier is impregnated with a hydrophilicity improver in advance before being newly introduced into the aeration tank, so that a special process may be performed when the sponge carrier is newly introduced into the aeration tank. And was able to be introduced easily and quickly.

  Further, in the above method, since the sponge carrier is impregnated with the hydrophilicity improver in the aeration tank, the sponge carrier can be used according to the actual situation of the aeration tank to be added, and the above effect can be achieved more efficiently. In addition, the sponge carrier impregnated with the hydrophilicity improver need not be stored and transported, and can be easily operated.

  In the above method, since the microorganisms and / or nutrients are loaded in advance on the sponge carrier before the introduction into the aeration tank, there is a waiting period until the microorganisms adhere to the sponge carrier in the aeration tank. Efficiently reduce the start-up time of the sewage treatment equipment / facility, fully demonstrate its functions immediately after the sponge carrier is introduced, and increase the treatment capacity even at the start-up, carrier exchange Sometimes it was possible to keep the processing capacity high. In particular, by supporting nutrients, microorganisms can be efficiently propagated, and the above-described effects can be further enhanced.

  The present invention will be described in detail below. The sponge carrier and the sewage treatment method of the present invention are used in sewage treatment in a sewage treatment apparatus using an activated sludge treatment method for organic sewage.

  Such a sewage treatment apparatus 100 includes a flow rate adjustment tank 1, an aeration tank 2, a solid-liquid separation tank 3, a sludge concentration tank 4, a sludge storage tank 5, and the like, and collects sewage, drainage, human waste, and the like. Organic sewage is stored in the flow rate adjusting tank 1 and the amount of sewage to be processed is adjusted and sent to the aeration tank 2. In the aeration tank 2, the sponge carrier 10, microorganisms, activated sludge and the like are stored together with the sewage 30. Microorganisms adhere to the sponge carrier 10.

  At the bottom of the aeration tank 2, there is provided an aeration apparatus including an aeration pipe 22 connected to a blower 21 for sending a gas containing a certain amount of oxygen such as air into the aeration tank 2. An oxygen-containing gas such as is continuously supplied into the aeration tank 2. Due to this gas supply and aeration, convection as shown by arrow A in FIG. 2 occurs in the sewage in the aeration tank 2, and the sewage 30 and activated sludge are mixed and oxygen is supplied to the microorganisms. The sponge carrier 10 flows in the sewage 30 in accordance with the convection generated in the aeration tank 2 by the air supplied from the diffuser tube 22. In the aeration tank 2, organic substances are decomposed and sewage is treated by the action of microorganisms.

  The sewage treated in the aeration tank 2 is mixed with the activated sludge and sent to the solid-liquid separation tank 3, where it is separated into treated water and sludge. Then, the treated water is discharged, and a part of the sludge is returned to the aeration tank 2 through the return sludge line 6 as a return sludge by a pump (not shown), and a part of the sludge is stored as a surplus sludge in the surplus sludge line 7 as a sludge concentration tank 4. , Concentrated in the sludge concentration tank 4, sent to the sludge storage tank 5, and discarded. A net or the like is provided at the outlet of the aeration tank 2 to prevent the sponge carrier 10 from flowing out.

  In the above description, the processing apparatus including a plurality of tanks such as an aeration tank and a solid-liquid separation tank is described. However, the present invention is not limited to such a processing apparatus, and includes a plurality of tanks. Instead, it can also be used in a batch activated sludge treatment apparatus that performs a plurality of treatments such as aeration and separation in one tank. Therefore, since the tank used in the batch type also includes an aeration apparatus constituted by a blower, an air diffuser, etc., the tank used in the batch type is also included in the aeration tank referred to in the present invention.

  The sponge carrier used in the present invention is not particularly limited as long as it is porous and can flow in the sewage in the aeration tank, but the density is low and the specific gravity is the same as that of water when it is hydrated. By using this, it is preferable because it can flow well in the aeration tank, and a high surface area is preferable. Examples of sponge carriers include sponge natural sponges and synthetic sponges. Examples of synthetic sponges include ether foams or ester polyurethane foams, polyolefin foams such as polyethylene sponge and polypropylene sponge, rubber sponges, and latex. A sponge etc. are mentioned.

  The shape of the sponge carrier is not particularly limited, and may be various other shapes such as a granular shape, a spherical shape, a prism shape, a pellet shape, a cylindrical shape, a fiber shape, and a film shape. Also, the dimensions are not particularly limited, and it is easy to manufacture and handle depending on the size of the aeration tank, the shape of the sponge carrier, the input amount, etc., can prevent leakage from the aeration tank, the efficiency of contact with sewage, microorganisms In consideration of the carrying efficiency, a material having an appropriate size may be used.

  The input amount of the sponge carrier is not particularly limited, and it is performed within the range of the normal input amount. However, the input amount is approximately 20 to 35% of the aeration tank in terms of volume ratio.

  Examples of the hydrophilicity improver of the sponge carrier include surfactants, alcohols, fatty acids, acetone, ammonia water, amines, and the like, and one or more of these can be used as appropriate. . As the surfactant, any of an anionic surfactant, a cationic surfactant, a nonionic surfactant and an amphoteric surfactant may be used, and alcohols are not particularly limited, such as methanol, ethanol, propanol and the like. The fatty acids are not particularly limited, such as formic acid, acetic acid, propionic acid, and the like, and the amines can be used without being particularly limited, such as methylamine and ethylamine.

  Among these hydrophilicity improvers, surfactants are particularly desirable and most practical because surfactants are highly effective in improving hydrophilicity and exhibit sufficient effects even at low concentrations. Among the surfactants, an anionic surfactant is highly effective and preferable, and among the anionic surfactants, alkylbenzene sulfonic acid sodium soda is very effective and can be suitably used.

  The method of applying and impregnating the hydrophilicity improver to the sponge carrier is not particularly limited, and a liquid hydrophilicity improver or a diluted solution thereof is prepared, and these solutions are sprayed or sprayed using a spray or the like to form a sponge carrier. For example, a method of applying and impregnating a sponge carrier, a method of immersing a sponge carrier in a liquid hydrophilic improver or a diluted solution thereof, and impregnating the sponge carrier can be employed.

  In addition, when using surfactant as a hydrophilic improvement agent, it is preferable to mix | blend antifoamers, such as a silicon antifoamer.

  Further, there is a method in which the sponge carrier is impregnated with the hydrophilicity improver in this way, and then used in a wet state. After impregnation, the sponge carrier may be once dried and impregnated with water at the time of use.

  When the sponge carrier is actually put into the aeration tank using these methods, after the sponge carrier is put into the aeration tank, the sponge carrier is impregnated with the hydrophilicity improver in the aeration tank. Any method of charging the impregnated sponge carrier into the aeration tank can be employed.

  As a method of impregnating the sponge carrier with the hydrophilicity improver in the aeration tank, (1) the sponge carrier is put into an empty aeration tank when the sewage treatment apparatus / facility is started up, The sponge carrier is impregnated with the hydrophilicity improving agent by spraying or spraying the hydrophilicity improving agent or a diluted solution thereof. Next, a method in which a small amount of water or sewage is put into an aeration tank, and stirring is performed with air so that the sponge carrier absorbs water. (2) It is possible to put a small amount of water or sewage and a hydrophilicity improver into an aeration tank, perform aeration, and then introduce a sponge carrier into the aeration tank and impregnate the sponge carrier with the hydrophilicity improver. I can do it.

  In addition, as a method of charging a sponge carrier impregnated with a hydrophilicity improver in advance into the aeration tank, the sponge carrier is charged into a tank or the like separate from the sewage treatment tank such as the aeration tank, and the sponge carrier is liquidated. A sponge carrier is impregnated with a hydrophilicity improver by spraying or spraying a hydrophilic improver in the form of a liquid or a diluted solution thereof. Next, it is possible to employ a method in which a normal amount of sewage is filled in an aeration tank and a sponge carrier impregnated with a hydrophilicity improver is introduced into an aeration tank in which aeration is performed. In this method, a sponge carrier impregnated with a hydrophilicity improving agent may be used in a wet state, but a sponge carrier once dried as described above can also be used.

  The sponge carrier may be loaded with microorganisms and / or nutrients in advance before being introduced into the aeration tank. By supporting microorganisms in advance, organic substances can be sufficiently decomposed immediately after the introduction of the new sponge carrier without passing through a state where the treatment capacity is low while the microorganisms adhere to the sponge carrier. High-load processing is possible. Nutritional components are for growing microorganisms. By supporting the nutritional components, the growth rate of microorganisms is increased, and organic substances are sufficiently decomposed immediately after the introduction of a new sponge carrier. And high load treatment of sewage becomes possible.

  The microorganism is not particularly limited as long as it is a microorganism that is used in a normal activated sludge method. , Pediococcus genus and the like, and these microorganisms are supported on a sponge carrier by appropriately combining one or more microorganisms.

  The nutrient component is not particularly limited as long as it is a nutrient for the microorganism as described above. For example, urea, ammonium sulfate such as ammonium sulfate, ammonium citrate, ammonium nitrate, and ammonium chloride, phosphoric acid, and phosphoric acid Phosphate such as monopotassium, dipotassium phosphate, monosodium phosphate, ammonium phosphate, sodium pyrophosphate, sodium hexametaphosphate, calcium phosphate, calcium salts such as calcium chloride, calcium silicate, calcium nitrate, Examples include magnesium salts such as magnesium sulfate, magnesium chloride, and magnesium nitrate, iron salts such as ferrous chloride, ferric chloride, ferrous sulfate, and ferric nitrate, various sugars, and various amino acids. One or two or more nutrients are appropriately combined and supported on the sponge carrier.

  The method for supporting microorganisms and nutritional components on the sponge carrier is not particularly limited, and a method of preparing an aqueous solution of microorganisms and nutritional components, spraying or spraying the aqueous solution using a spray or the like, and applying and impregnating the sponge carrier, A method of immersing a sponge carrier in an aqueous solution of microorganisms or nutritional components and impregnating the sponge carrier can be employed.

  To confirm the hydrophilic effect when the sponge carrier contains a hydrophilicity improver, prepare a constant concentration aqueous solution of the hydrophilicity improver, place it in a beaker, and place the sponge carrier gently on the liquid surface. The water absorption state of the sponge carrier was observed in a stationary state. A sponge carrier having a 1 cm square cube and a weight of about 0.03 g was used. Tests were conducted on a hydrophilicity improver and water as a comparative example. The hydrophilicity improvers used and the results are shown in Table 1 below. In the table, “%” means “% by weight”.

  From the above test, it was found that the hydrophilicity-improving agent increases the water absorption of the sponge carrier, so that it can be easily adapted to water.

  An aqueous solution was prepared according to the formulation shown in Table 2 below in order to support the hydrophilicity improver, microorganisms and nutrients on the sponge carrier. Seaweed extract is an extract extracted from seaweed, and is a nutrient containing minerals such as potassium salts.

  An aqueous solution obtained by diluting this aqueous solution with water at an appropriate dilution rate was placed in a beaker, and the sponge carrier was gently placed on the liquid surface, and the water absorption state of the sponge carrier was observed in a stationary state. A sponge carrier having a 1 cm square cube and a weight of about 0.03 g was used. Tests were conducted on water containing a hydrophilicity improver and water containing no hydrophilicity improving agent as a comparative example. The dilution factors tested and the results are shown in Table 3 below.

  From the above test, it was found that even with a sponge carrier carrying microorganisms and nutrients, the hydrophilicity-improving agent increases the water absorption of the sponge carrier, so that it can be easily adapted to water.

  A 100-fold diluted aqueous solution of the aqueous solution prepared according to the formulation in Table 2 was prepared using water and placed in a spray container. 100 sponge sponges having a 1 cm square cube and a weight of about 0.03 g were put in a beaker, and the same amount of the aqueous solution as the total weight of the sponge carrier was sprayed to uniformly impregnate the carrier. This sponge carrier was put into a 30-liter simulated aeration tank in which water was filled and aerated, and the behavior of the sponge carrier was observed. As a comparative example, an untreated sponge carrier was similarly put into a simulated aeration tank, and the behavior of the sponge carrier was observed.

  The sponge carrier impregnated with the aqueous solution all entered water immediately after the addition, and showed fluidity by the water flow by aeration. On the other hand, all the untreated sponge carriers remained floating on the water even after 5 hours, and showed no fluidity.

  From the above test, it can be seen that by impregnating the sponge carrier with the hydrophilicity improver, the sponge carrier quickly absorbs water, becomes familiar with water and can flow in the aeration tank.

1 is a conceptual diagram of one embodiment of a sewage treatment apparatus using the present invention. The schematic diagram of one form of the aeration tank using the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flow control tank 2 Aeration tank 3 Solid-liquid separation tank 4 Sludge concentration tank 5 Sludge storage tank 6 Return sludge line 7 Surplus sludge line 10 Sponge carrier 21 Blower 22 Aeration pipe 30 Sewage 100 Sewage treatment apparatus

Claims (6)

  A sponge carrier, which is introduced into an aeration tank and retains microorganisms in an equipment for treating organic sewage using an activated sludge method, which is impregnated with a hydrophilicity improver.   The sponge carrier according to claim 1, wherein the sponge carrier carries microorganisms and / or nutrients.   Sewage characterized by using a sponge carrier impregnated with a hydrophilicity improver in the introduction of a sponge carrier for retaining microorganisms into an aeration tank in a facility for treating organic sewage using the activated sludge method Processing method.   The sewage treatment method according to claim 3, wherein the sponge carrier is impregnated with a hydrophilicity improver in advance before being newly introduced into the aeration tank.   The sewage treatment method according to claim 3, wherein the sponge carrier is impregnated with a hydrophilicity improver in an aeration tank.   The sewage treatment method according to any one of claims 3 to 5, wherein the sponge carrier is loaded with microorganisms and / or nutrients in advance before being newly introduced into the aeration tank.

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