JP2013208563A - Anaerobic treatment method for organic waste water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anaerobic treatment method for organic waste water, which can prevent coloring of treated water by a hydrophilizing agent eluted from a carrier when an anaerobic treatment is started.SOLUTION: In an anaerobic treatment method for organic waste water in which a resin carrier containing a hydrophilizing agent is added to an anaerobic reactor tank 3 to perform treatment with anaerobic microorganisms composed mainly of methane bacteria adhered to the surface of the resin carrier, activated carbon is added to the anaerobic reactor tank 3 together with the resin carrier. As the activated carbon, powdered activated carbon is preferable.

Description

  The present invention relates to a method for anaerobically biologically treating organic wastewater, and more particularly to an anaerobic treatment method in which a resin carrier is added to an anaerobic reaction tank.

  In the anaerobic treatment method of organic wastewater using a fluid non-biological carrier, microorganisms grow on the surface of the carrier, so even if it is a low-concentration COD wastewater or an organic wastewater whose granules are dismantled It can be processed efficiently.

  Patent Document 1 discloses a foam containing 30 to 95% by weight of a polyolefin resin and 5 to 70% by weight of a hydrophilizing agent for cellulose powder as a fluid processing carrier comprising a polyolefin foam having excellent fluid processing performance. What consists of is described.

  Since the resin is hydrophobic, the resin carrier contains a hydrophilizing agent because it has poor wettability and water sedimentation.

JP2009-66592A

  Immediately after the resin carrier containing the hydrophilizing agent is introduced into the anaerobic reaction tank, the hydrophilizing agent is eluted from the carrier into the water, and the COD and chromaticity of the anaerobic treated water are increased. In the latter part of the anaerobic treatment, aerobic treatment such as activated sludge and aerobic fluidized bed is often performed, and most of the COD components derived from the hydrophilizing agent are decomposed by the aerobic treatment, but the chromaticity component is removed. Since it was difficult, there was a problem that the treated water discharged from the wastewater treatment was colored at the beginning of anaerobic treatment.

  An object of this invention is to provide the anaerobic processing method of the organic waste water which can prevent the coloring of treated water by the hydrophilizing agent eluted from the support | carrier at the time of the start of anaerobic processing.

  The method for anaerobic treatment of organic waste water according to the present invention comprises adding a resin carrier containing a hydrophilizing agent to an anaerobic reaction tank, and performing treatment with anaerobic microorganisms attached to the surface of the resin carrier. In the method, activated carbon is added to the anaerobic reaction tank together with a resin carrier.

  According to the present invention, the chromaticity component eluted from the resin carrier at the initial start-up of the anaerobic treatment using the resin carrier is adsorbed on the activated carbon and removed from the treated water. Anaerobic treatment can be launched.

It is a flowchart of an Example. It is a graph which shows an experimental result. It is a graph which shows an experimental result.

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

  In the present invention, when an organic waste water is subjected to an anaerobic treatment, activated carbon is added to an anaerobic reaction tank together with a resin carrier.

  The material of the resin carrier is not particularly limited, but polyolefin, polyvinyl alcohol, particularly polypropylene, etc. are suitable. The shape of the carrier is arbitrary such as a spherical shape, a pellet shape, a hollow cylindrical shape, and a thread shape. The size (diameter) of the carrier is preferably about 0.1 to 10 mm, particularly about 1 to 5 mm, but is not limited thereto. This resin carrier contains a hydrophilizing agent such as propylene glycol, ethylene glycol, glycerin and the like.

  It is preferable to add 10 to 60% (particularly 40 to 60%) of the resin carrier to the anaerobic reaction tank.

  The activated carbon charged into the anaerobic reaction tank together with the resin carrier may be either powdered or granular, but powdered activated carbon is particularly preferable. By using powdered activated carbon, the activated carbon surface area per unit volume is increased, and the amount of activated carbon used can be suppressed. In addition, when using powdered activated carbon, since it is easy to float at the time of injection | throwing-in, it is preferable to introduce | transduce activated carbon first into a reaction tank, and, after that, a support | carrier and seed sludge are thrown in.

  The input amount of the activated carbon is preferably 0.5 to 3 times, particularly 1 to 2 times the amount of adsorption of the chromaticity component eluted from the carrier. Since the amount of adsorption of the chromaticity component by the activated carbon varies depending on the activated carbon and the chromaticity component to be used, it is preferable to obtain the amount by the method defined in JIS K1474 (activated carbon test method).

  Since the elution of the chromaticity component is a temporary one that does not last for several days to several months, the activated carbon does not need to be held in the anaerobic reaction tank throughout the entire period of wastewater treatment, and may flow out. The discharged activated carbon is usually separated from the water together with the biologically treated sludge by a solid-liquid separation means after the aerobic treatment tank provided in the subsequent stage of the anaerobic reaction tank and discharged.

  In this invention, you may provide an acid production tank in the front | former stage of an anaerobic reaction tank. Circulating the anaerobic treated water in the acid production tank 0.5 to 10 times the amount of the raw water, mixing with the raw water and introducing it into the anaerobic reaction tank, using the alkalinity of the anaerobic treated water at the time of acid generation The amount of alkali used for neutralization can be reduced.

  FIG. 1 is a flowchart showing an example of an organic wastewater treatment apparatus including an acid generation tank, an anaerobic reaction tank, an aerobic tank, and a precipitation tank.

  Raw water (organic waste water) is introduced into the anaerobic reaction tank 3 through the acid generation tank 1 and the pipe 2. A carrier, seed sludge, and powdered activated carbon are added to the anaerobic reaction tank 3. The anaerobic treated water flowing out from the upper part of the anaerobic reaction tank 3 through the screen 3 a is introduced into the aerobic tank 6 through the pipe 4, and a part thereof is introduced into the acid generation tank 1 through the return pipe 5. Will be returned.

  In the aerobic tank 6, air is aerated from the diffusing tube 6a and an aerobic treatment is performed. Aerobic treated water is introduced into the sedimentation tank 7, and aerobic treated water is taken out. A part of the precipitated sludge is returned to the aerobic tank 6 and the excess sludge is discharged out of the system.

[Example 1]
In accordance with the flow shown in FIG. 1, the following raw water is treated using the following anaerobic reaction tank and aerobic tank, and 0.4 g of powdered coconut shell activated carbon (100 mesh (diameter 0.15 mm or less)) is charged into the anaerobic reaction tank. did. The amount of water returned to the acid generation tank was 16 L / d.

<Raw water>
Synthetic wastewater quality mainly composed of acetic acid: pH 7.5, BOD 3,000 mg / L, TN 15 mg N / L, PO4-P 2 mg P / L (added as a nutrient with other trace metals and minerals)
Water volume: 16L / d
Water flows upward in an anaerobic reaction tank.
<Anaerobic reaction tank>
Tank capacity 4L (cylindrical shape of φ10cm x H50cm)
Temperature 30 ° C
0.8L of anaerobic granules from a beer factory wastewater treatment facility as seed sludge and 1.6L of polypropylene cylindrical carrier (φ3mm × 5mm) are introduced.

<Aerobic tank>
Tank capacity 4L
Activated sludge (MLSS approx. 6,000 mg / L) from a wastewater treatment facility at a beer factory is used as seed sludge.
Adjust to pH 6.8 (add 1N NaOH)

[Comparative example]
The treatment was performed under the same conditions as in Example 1 except that the activated carbon was not charged into the anaerobic reaction tank.

[result]
In both Example 1 and Comparative Example 1, continuous water flow was started when 2 days had passed after the carrier and seed sludge were put into the anaerobic reaction tank. Changes in BOD and chromaticity of anaerobic and aerobic treated water for one month after the start of water flow are shown in FIGS. In both Comparative Example 1 and Example 1, the BOD concentration was about 600 mg / L for anaerobic treated water (removal rate 80%) and 10 for aerobic treated water immediately after the start of water flow with respect to 3,000 mg / L for raw water. It was changing at ˜15 mg / L, and good treatment was performed. On the other hand, the chromaticity continued for about 1 week in Comparative Example 1 and 10 degrees or higher, which was higher than that in Example 1, and the treated water in the meantime was brown. On the other hand, in Example 1, the good state of 10 degrees or less with anaerobic treated water and 5 degrees or less with aerobic treated water was maintained immediately after the start of water flow.

  As is clear from these examples and comparative examples, according to the present invention, in the start-up of the anaerobic treatment using the carrier, the anaerobic treatment is started without any problem of deterioration of the treated water due to the chromaticity component eluted from the carrier. Can be raised.

1 Acid generation tank 3 Anaerobic reaction tank 6 Aerobic tank 7 Precipitation tank

Claims (2)

  In an anaerobic treatment method for organic waste water, wherein a resin carrier containing a hydrophilizing agent is added to an anaerobic reaction tank and treated with anaerobic microorganisms attached to the surface of the resin carrier. An anaerobic treatment method for organic wastewater, characterized by being added to the above.   2. The method for anaerobic treatment of organic waste water according to claim 1, wherein the activated carbon is powdered activated carbon.

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