JP6422683B2 - Anaerobic biological treatment apparatus and anaerobic biological treatment method - Google Patents

Description

  The present invention relates to an anaerobic biological treatment apparatus and anaerobic biological treatment method for biologically treating organic matter-containing wastewater under anaerobic conditions.

  In general, organic matter-containing wastewater discharged from ham factories, frozen food manufacturing factories, side dish factories, dairy product manufacturing factories, seasoning manufacturing factories, etc. includes fats and oils such as animal and vegetable oils and suspended solids (SS). Yes. Examples of a method for treating organic matter-containing wastewater containing fats and oils and suspended solids include a UASB (Upflow Anaerobic Sludge Blanket) method using anaerobic granular sludge, and an EGSB (Expanded Granular Sludge Method) improved from this. . However, in these methods, suspended solids and oils and fats adhere to the granule sludge, the granule sludge floats up, or the granule sludge is disassembled and refined, and flows into the treated water, causing no treatment. Sometimes it became stable. Therefore, as a pretreatment, it is common to perform anaerobic treatment using granular sludge after adding a flocculant to the waste water and performing pressure levitation treatment to remove oil and fat and suspended substances (for example, Patent Document 1). In anaerobic treatment using such granular sludge, organic substance-containing wastewater with a normal hexane extract substance concentration (oil concentration) of less than 100 mg / L or an SS concentration (suspension substance concentration) of less than 100 mg / L is usually treated. It becomes a target.

  However, in the method in which the pretreatment and the anaerobic treatment using granular sludge are used in combination, the increase in the amount of oil-containing sludge, the generation of odor from the sludge, the increase in the amount of flocculant added, and the like are problems.

  In order to suppress the reduction of the amount of oil-containing sludge, the amount of flocculant added, etc., for example, Patent Document 2 discloses that the oil-containing sludge generated by the pressure flotation treatment is saponified and then subjected to acid fermentation under alkaline conditions. A method of performing acid fermentation and methane fermentation under alkaline conditions without separating fats and oils and wastewater is proposed in Patent Document 3.

  However, in the method of Patent Document 2, since the oil-containing sludge containing bubbles is treated, there arises a problem that the anaerobic treatment efficiency is lowered and the chemical cost used for pH adjustment and aggregation is required. In addition, the method of Patent Document 3 requires a problem that a chemical cost necessary for pH adjustment is required, and a two-stage treatment of an acid generation tank and a methane generation tank is essential, ensuring a processing space and complicating the apparatus configuration. Such a problem occurs.

  There is also a method of anaerobic treatment using granulated sludge after pressure flotation treatment without adding a flocculant, but this method results in insufficient removal of fats and oils and suspended matter, and granule sludge. There may be cases where the surface of the material becomes finer. Therefore, it is necessary to replenish the granular sludge once every several months, and there are problems in terms of the purchase cost and operation management of the granular sludge.

JP 2010-012446 A JP 2000-271593 A JP2013-208559A JP-A-5-277493

  An object of the present invention is to provide an anaerobic biological treatment apparatus and an anaerobic biological treatment method capable of stably treating anaerobic biological wastewater containing organic matter having a high normal hexane extractable substance concentration or a high SS concentration at a high load. It is in.

The present invention is an anaerobic biological treatment apparatus for biologically treating an organic matter-containing wastewater having a normal hexane extract substance concentration of 100 mg / L or more and an SS concentration of 100 mg / L or more under anaerobic condition from the start of anaerobic biological treatment, A tank-type biological treatment tank for anaerobic biological treatment of the organic matter-containing wastewater in the presence of a carrier; and an agitator for stirring the organic matter-containing wastewater and the carrier in the tank-type biological treatment tank , The carrier is an anaerobic biological treatment apparatus in which the carrier is a gel-like carrier and the specific gravity of the carrier is greater than 1 .

  Moreover, in the anaerobic biological treatment apparatus, it is preferable that a pretreatment apparatus for separating fats and oils or suspended substances from the organic matter-containing wastewater is not installed in the previous stage of the one-tank biological treatment tank.

In the anaerobic biological treatment apparatus, it is preferable that the anaerobic biological treatment is performed at an organic substance load of 10 kg CODcr / m ³ / d or more in the one-tank biological treatment tank.

In the anaerobic biological treatment apparatus, the biological treatment is performed under anaerobic conditions without diluting the normal hexane extractable substance concentration and the SS concentration from the start of the anaerobic biological treatment. it is preferable to perform.

  Moreover, the said anaerobic biological treatment apparatus WHEREIN: It is preferable to provide a pressurized levitation processing apparatus in the back | latter stage of the said 1 tank type biological treatment tank.

In addition, the present invention is an anaerobic biological treatment method in which an organic matter-containing wastewater having a normal hexane extract substance concentration of 100 mg / L or more and an SS concentration of 100 mg / L or more is biologically treated under anaerobic conditions from the start of anaerobic biological treatment. Te, in 1-tank type biological treatment tank in which carriers are filled, seen including a biological treatment step of anaerobic biological treatment of the organic substance-containing waste water while stirring the organic matter containing wastewater and the carrier, the carrier is a gel-like carrier The specific gravity of the carrier is an anaerobic biological treatment method greater than 1 .

  Moreover, in the said anaerobic biological treatment method, it is preferable not to perform the pretreatment process which isolate | separates fats and oils or suspended solids from the said organic substance containing waste_water | drain before the said biological treatment process.

In the anaerobic biological treatment method, the anaerobic biological treatment is preferably performed at an organic substance load of 10 kg CODcr / m ³ / d or more in the biological treatment step.

Further, in the anaerobic biological treatment method, in the one-tank biological treatment tank, the biological treatment is performed under anaerobic conditions without diluting the normal hexane extract substance concentration and the SS concentration from the start of the anaerobic biological treatment. Preferably it is done .

  In the anaerobic biological treatment method, it is preferable that a pressurized flotation treatment step is included after the biological treatment step.

  According to the present invention, an organic substance-containing wastewater having a high normal hexane extractable substance concentration or a high SS concentration can be stably anaerobically treated with a high load.

It is a schematic block diagram which shows an example of the anaerobic biological treatment apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the other example of the anaerobic biological treatment apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the other example of the anaerobic biological treatment apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the anaerobic biological treatment apparatus used by the test of the comparative example. It is a figure which shows transition of the organic substance load of Example 1 and a comparative example from the 50th day of water flow to the 100th day of water flow. It is a figure which shows transition of the organic substance load of Example 1 and a comparative example from the 91st day of water flow to the 117th day of water flow.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

  Anaerobic biological treatment reduces the energy cost of aeration, reduces the amount of sludge generated, and recovers methane gas generated during anaerobic treatment as energy. Application to various wastewater is being studied. Thus, for example, it has been studied to treat wastewater containing organic matter containing high-concentration oil or suspended matter discharged from food factories using granule sludge. Consideration of drainage concentration, installation of pretreatment such as pressurized flotation, etc. have been studied, and maintenance and stabilization of granule sludge have been made. The present inventors can perform a stable anaerobic treatment with high load without installing pretreatment such as pressure flotation, acid fermentation tank, alkali treatment, enzyme treatment, etc. in such technical trends. For the purpose of developing the technology, we have intensively studied the carrier used in anaerobic treatment, reaction type, etc. As a result, the carrier and the organic matter-containing wastewater are agitated and the organic matter-containing wastewater is subjected to anaerobic biological treatment, so that even in an organic matter-containing wastewater having a normal hexane extractable substance concentration of 100 mg / L or more or an SS concentration of 100 mg / L or more, for example It has been found that it can be stably treated for a long time with a high load more than twice the treatment speed using granular sludge. Although details are unknown, since the carrier is agitated, an appropriate shearing force acts between the carriers, and adhesion of oils and fats and suspended solids to the carrier is suppressed, so that organic matter in organic matter-containing wastewater is decomposed. It is thought to be promoted.

  FIG. 1 is a schematic configuration diagram illustrating an example of an anaerobic biological treatment apparatus according to an embodiment of the present invention. An anaerobic biological treatment apparatus 1 shown in FIG. 1 is a one-tank type anaerobic biological treatment apparatus 1 having only one anaerobic biological treatment tank. It is provided with a draft tube 12 that is installed substantially vertically inside the biological biological treatment tank 10 and that is open at the top and bottom, and a stirring device 14 having stirring blades and the like. A carrier 16 is introduced into the one-tank biological treatment tank 10. You may equip the front | former stage of the 1 tank type biological treatment tank 10 with the raw | natural water tank which stores raw | natural water.

  An operation of the anaerobic biological treatment method and the anaerobic biological treatment apparatus 1 according to the present embodiment will be described.

  The organic matter-containing wastewater to be treated in the present embodiment is an organic matter-containing wastewater having a normal hexane extractable substance concentration of 100 mg / L or higher or an SS concentration of 100 mg / L or higher, and organic substances other than fats and oils, suspended substances, fats and suspended substances. Etc. (hereinafter simply referred to as organic matter-containing wastewater).

  Organic matter-containing wastewater is introduced into the one-tank biological treatment tank 10 from the inlet of the one-tank biological treatment tank 10. Before or after the organic matter-containing wastewater is introduced, the carrier 16 is introduced into the one-tank biological treatment tank 10 and anaerobic sludge is added as seed sludge. In the 1 tank type biological treatment tank 10, anaerobic biological treatment is performed while the carrier 16 and the organic matter-containing wastewater are stirred by the stirring device 14 (biological treatment step). By stirring in the draft tube 12, a downward flow is formed in the draft tube 12, and an upward flow is formed between the draft tube 12 and the inner wall surface of the single tank biological treatment tank 10. The treated water that has been subjected to the anaerobic biological treatment is discharged from the outlet of the one-tank biological treatment tank 10.

  When the organic substance-containing wastewater having a normal hexane extractant concentration of 100 mg / L or higher or an SS concentration of 100 mg / L or higher is to be treated with a conventional apparatus in which the carrier 16 in the biological treatment tank is not stirred by the stirring device 14, It is thought that stable and high-load treatment cannot be performed for a long period of time because the carrier floats or adheres to the methane-fermenting bacteria capable of decomposing organic matter. However, according to the present embodiment, the carrier 16 is stirred by the stirring device 14 and a shearing force acts between the carriers 16, so that adhesion of oils and fats and suspended substances to the carrier 16 is suppressed. As a result, the floating of the carrier 16 is suppressed, and the methane fermentation bacteria adhere to the carrier 16 or is immobilized inside the carrier 16. Therefore, in anaerobic treatment involving methane fermentation of organic matter-containing wastewater, high stability is achieved over a long period of time. Load processing can be performed. Therefore, before the anaerobic biological treatment by the one-tank biological treatment tank 10, it is not necessary to carry out a pretreatment for separating fats and oils and suspended substances from the organic waste water, for example, a pressure levitation treatment. That is, organic substance-containing water containing high-concentration fats and oils or suspended substances can be directly introduced into the one-tank biological treatment tank 10. Moreover, since organic substance containing water is also stirred by the stirring apparatus 14, it is suppressed that the inlet_port | entrance etc. of the 1 tank type biological treatment tank 10 are obstruct | occluded with fats and oils or suspended solids.

  Moreover, according to this embodiment, since fats and oils and suspended substances are also stirred, untreated fats and oils and suspended substances are also discharged from the outlet of the one-tank biological treatment tank 10, but normal hexane extraction from the treated water is performed. When the substance concentration or the SS concentration is high, it is preferable to install a pressure levitation device at the subsequent stage of the one-tank biological treatment tank 10 to separate fats and oils and suspended substances from the treated water.

  The carrier 16 used in the present embodiment is not particularly limited as long as it is a carrier conventionally used in anaerobic biological treatment, and examples thereof include a plastic carrier, a sponge carrier, a gel carrier and the like. In particular, by using a gel-like carrier, methane-fermenting bacteria that do not produce a high molecular polymer easily enter into the pores of the three-dimensional network structure of the gel-like carrier, or adhere due to the shape, charge, etc. of the gel-like carrier, In addition, since the fluidity of the carrier by stirring is high, a high load treatment is possible as compared with a plastic carrier and a sponge carrier.

  The gel carrier is not particularly limited, and examples thereof include a water-absorbing polymer gel carrier containing polyvinyl alcohol, polyethylene glycol, polyurethane and the like.

  The larger the pore diameter of the carrier 16, the easier the organic substance diffuses into the inside of the carrier 16, but gas is likely to be generated inside the carrier 16, and bubbles may remain inside the carrier 16 and float. A pore diameter as small as possible (for example, about 1 μm to 20 μm) is preferable.

  The shape of the carrier 16 is not particularly limited, but is preferably spherical or cubic (cube), rectangular, cylindrical, etc. having a diameter of about 0.5 mm to 20 mm. In particular, a spherical or cylindrical gel carrier having a diameter of about 3 to 8 mm is preferable. When the diameter of the carrier 16 is less than 0.5 mm, clogging is likely to occur in a separator such as a screen that separates the carrier 16 and the treated water. When the diameter of the carrier 16 exceeds 10 mm, the surface area may be reduced and the processing speed may be reduced.

  In order to form a fluid state in the single tank biological treatment tank 10, the specific gravity of the carrier 16 is at least larger than 1.0, and the true specific gravity is preferably 1.1 or more, or the apparent specific gravity is 1.01 or more. .

  The input amount of the carrier 16 to the single tank biological treatment tank 10 is preferably in the range of 10 to 50% with respect to the volume of the single tank biological treatment tank 10. When the input amount of the carrier 16 is less than 10% with respect to the volume of the one-tank biological treatment tank 10, the reaction rate may be small. When it exceeds 50%, the carrier 16 is difficult to flow, and sludge is produced in a long-term operation. The raw water may be short-passed due to clogging, etc., and the treated water quality may deteriorate.

  The sedimentation rate of the carrier 16 is preferably 100 to 150 m / hr. When the sedimentation speed of the carrier 16 is less than 100 m / hr, the carrier 16 is likely to float and easily flow out of the one-body biological treatment tank 10, and the separation screen may be clogged. If it exceeds 150 m / hr, the fluid state may deteriorate, and the carrier 16 may short-pass or the stirring energy may increase.

  In this embodiment, when biologically treating organic matter-containing wastewater, the pH of the wastewater is preferably in the range of 6.0 to 8.0, and more preferably in the range of 7.0 to 8.0. The pH adjustment of the waste water is performed, for example, by supplying a pH adjuster to a raw water tank (not shown) from a pH adjuster supply line (not shown). If the pH of the organic matter-containing wastewater is outside the above range, the decomposition reaction rate of organic matter due to biological treatment may decrease.

  The pH adjuster is not particularly limited, such as an acid agent such as hydrochloric acid or an alkali agent such as sodium hydroxide. Further, the pH adjusting agent may be, for example, sodium bicarbonate having a buffering action, a phosphate buffer or the like.

  FIGS. 2-3 is a schematic block diagram which shows the other example of the anaerobic biological treatment apparatus which concerns on embodiment of this invention. The anaerobic biological treatment apparatus 2 shown in FIG. 2 does not include the draft tube 12, but includes a one-tank biological treatment tank 10, a stirring device 14 having stirring blades, and the like. The carrier 16 and the organic matter-containing wastewater in the tank 10 are agitated.

  The anaerobic biological treatment apparatus 3 shown in FIG. 3 includes a submersible pump 18 below the draft tube 12. The anaerobic biological treatment apparatus 3 draws water from above by the submersible pump 18 and discharges it from the side. A counterflow is formed, an upward flow is formed between the draft tube 12 and the inner wall surface of the one-tank biological treatment tank 10, and the carrier 16 and the organic matter-containing wastewater are agitated.

  The shape of the single tank biological treatment tank 10 may be rectangular or cylindrical, and is not particularly limited. In order to suppress the deposition of the carrier 16 on the bottom of the tank of the single tank biological treatment tank 10, a taper is attached to the bottom of the tank of the single tank biological treatment tank 10 as shown in FIGS. It is preferable that a taper taper of 45 degrees or more is particularly provided.

  In order to maintain the inside of the one-tank biological treatment tank 10 in an anaerobic state, and to collect and appropriately process generated methane gas, hydrogen sulfide gas, etc. when used for methane fermentation treatment of organic matter-containing wastewater. In addition, it is preferable that the upper part of the single tank biological treatment tank 10 has a sealed structure that is substantially shielded from the outside air.

  In the present embodiment, it is preferable that at least 1,000 mg / L or more of digested sludge, anaerobic granules, etc. are introduced into the one tank type biological treatment tank 10 together with the carrier 16 at the time of startup of the apparatus, and 1,000 to 10,000 mg. / L is more preferable. When the sludge concentration in the one-tank biological treatment tank 10 exceeds 10,000 mg / L, granule sludge or the like is unlikely to adhere to the carrier 16 and the effect of introducing the carrier 16 may be reduced.

  In this embodiment, when biologically treating organic matter-containing wastewater, in order to maintain the decomposition activity of anaerobic biological sludge satisfactorily, for example, nutrients are supplied from a nutrient supply line (not shown) to a raw water tank (not shown). It is preferable to supply an agent. Although it does not restrict | limit especially as a nutrient, For example, a carbon source, a nitrogen source, other inorganic salts (Ni, Co, Fe etc.) etc. are mentioned.

  In this embodiment, it is preferable to adjust the temperature so that the water temperature in the single tank biological treatment tank 10 is 20 ° C. or higher. Usually, it is preferable to adjust the temperature so as to be in the range of 28 ° C. or more and less than 35 ° C. However, in this embodiment, there is almost no fear that the granule sludge will collapse, so that the conventional anaerobic granule method cannot perform stable treatment. It becomes possible to operate at 28 ° C. or 20 to 25 ° C., which is preferable from the viewpoint of economical treatment. The decomposition of the organic substance by the anaerobic biological treatment is possible even at a temperature lower than 20 ° C. However, if it is lower than 20 ° C., the decomposition reaction rate tends to decrease.

  Although the temperature adjustment method of the water temperature in the 1 tank type biological treatment tank 10 is not particularly limited, for example, the water temperature in the 1 tank type biological treatment tank 10 is adjusted by supplying steam to the raw water tank. Alternatively, a heating device such as a heater may be installed in the single tank biological treatment tank 10, and the water temperature in the single tank biological treatment tank 10 may be adjusted by the heat of the heater or the like. Moreover, for example, the water temperature in the one-tank biological treatment tank 10 may be adjusted by supplying heated diluted water. In addition, for example, methane gas is generated by decomposition of organic matter, but after desulfurization treatment is performed in the same manner as normal anaerobic treatment, it is recovered as thermal energy with a methane gas boiler, and the thermal energy is supplied to the one-bath biological treatment tank 10. The water temperature may be adjusted. If processing can be performed at a lower temperature, the energy required for heating is unnecessary or less.

  In the present embodiment, it is possible to perform anaerobic biological treatment that is stable at high load with respect to organic matter-containing wastewater having a normal hexane extractant concentration of 100 mg / L or higher or an SS concentration of 100 mg / L or higher. It is possible to perform anaerobic biological treatment that is stable under high load even for organic substance-containing wastewater having an extractable substance concentration of 150 mg / L or more or an SS concentration of 200 mg / L or more.

  The normal hexane extractable substance concentration (oil concentration) is determined by the following method according to, for example, JIS K0102. First, an appropriate amount (about 200 to 1,000 ml) of organic substance-containing wastewater is put into a separatory funnel, and after adding a methyl orange solution dropwise, hydrochloric acid is dropped until the color of the solution changes to red. Then, adding 40 ml of normal hexane and shaking vigorously for 2 minutes was repeated twice. After separating only the normal hexane layer, filtration and dehydration were performed, and normal hexane was volatilized at 80 ° C. Obtain extract material. And the normal hexane extract substance density | concentration is calculated | required from the mass of the obtained normal hexane extract substance, and the mass of the input organic substance containing waste_water | drain.

  The SS concentration (suspended substance concentration) is measured according to, for example, JIS K0102.

  Organic substance-containing wastewater is wastewater containing organic substances (oils and fats, suspended substances, organic substances other than oils and suspended substances) discharged from, for example, food manufacturing factories, electronic industry factories, pulp manufacturing factories, and chemical factories. Oils and fats in organic matter-containing wastewater are substances extracted to the normal hexane side by mixing wastewater and normal hexane, and examples thereof include animal and vegetable oils and mineral oils. The anaerobic biological treatment according to this embodiment is particularly effective for organic matter-containing wastewater containing animal and vegetable oils. Suspended substances in organic matter-containing wastewater are insoluble substances contained in the liquid to be treated, such as biodegradable organic substances such as starch and cellulose, inorganic substances such as diatomaceous earth, sand and metals. Organic substances other than fats and suspensions are BOD components other than fats and suspensions and are biodegradable organics such as soluble proteins, sugars, amino acids, alcohols, organic acids, fatty acids, etc. Is mentioned.

This embodiment is particularly effective when the biological treatment is performed with an organic substance load of 10 kg CODcr / m ³ / d or more, preferably 15 kg CODcr / m ³ / d or more.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

Example 1
The test of Example 1 was conducted using the anaerobic biological treatment apparatus shown in FIG. The wastewater to be biologically treated in Example 1 is organic matter-containing wastewater containing fats and oils and suspended substances discharged from a food manufacturing factory. The organic matter-containing wastewater has a BOD concentration of 1,200 to 4,700 mg / L, a CODcr concentration of 2,000 mg / L to 8,000 mg / L, and a normal hexane extractant concentration of 100 mg / L to 200 mg / L. Yes, the SS concentration was 100 mg / L to 800 mg / L. Next, a spherical polyvinyl alcohol gel-like carrier (pore diameter: 4 μm to 20 μm, diameter: 4 mm, specific gravity: 1.025, sedimentation speed: 4 cm / sec) is placed in a single tank type biological treatment tank with an internal volume of 60 L. After adding anaerobic sludge (sludge concentration 5,000 mg / L) as seed sludge, the above waste water was passed through with a load of 10 kg CODcr / m ³ / d or more while observing the treated water quality. . The temperature when draining water into the biological treatment tank was adjusted to 25 to 30 ° C., and the pH was adjusted to 7 to 8 with sodium hydroxide (NaOH) and hydrochloric acid (HCl). The nutrient was not added because it was sufficiently contained in the wastewater.

(Comparative example)
The test of the comparative example was performed using the anaerobic biological treatment apparatus shown in FIG. An anaerobic biological treatment apparatus 4 shown in FIG. 4 is an upward flow anaerobic sludge blanket (UASB) treatment apparatus using anaerobic granules, and includes a tower-shaped biological treatment tank 20 and an upper part in the biological treatment tank 20. And a solid-liquid separation unit 22 disposed obliquely. In the anaerobic biological treatment apparatus 4 shown in FIG. 4, the same organic substance-containing water as in Example 1 is introduced into the biological treatment tank 20 from the lower entrance of the biological treatment tank 20, and the anaerobic granules 24 in the biological treatment tank 20 Anaerobic biological treatment was performed by contact. The treated water discharged from the biological treatment tank 20 is supplied to the organic matter-containing wastewater flowing into the biological treatment tank 20 through the circulation line 26 by a 10-fold amount, giving a flow rate to the granular sludge in the biological treatment tank 20, and containing organic matter. Increased contact efficiency between drainage and granular sludge. Other processing conditions were the same as in Example 1.

  FIG. 5 is a diagram showing the transition of the organic load of Example 1 and Comparative Example from the 50th day to the 100th day of water flow, and FIG. 6 shows the flow from the 91st day to the 117th day of water flow. It is a figure which shows transition of the organic substance load of Example 1 and a comparative example. In addition, it was set as the start-up period of the anaerobic biological treatment from the start of water flow to the 49th day in both Example 1 and Comparative Example.

As can be seen from FIG. 5 and FIG. 6, in Example 1, it was possible to perform the treatment with an organic load of 10 kg CODcr / m ³ / d or more and a maximum load of 40 kg CODcr / m ³ / d. And even if the said high load, the raise of the organic substance density | concentration in treated water was not seen, but the CODcr removal rate was about 70 to 80%, and it was able to perform the stable process. Moreover, in Example 1, the carrier floating by fats and oils and suspension substance adhesion was not seen during the test period.

On the other hand, in the comparative example, from the 70th day after the start of water flow, granule sludge floats out from the biological treatment tank 20 due to the floating and refinement of the granule sludge due to the adhesion of oils and suspended solids, and the organic matter concentration in the treated water When the organic matter load was 10 kg CODcr / m ³ / d or more, stable treatment could not be performed. In order to perform a stable biological treatment, the organic load had to be less than 10 kg CODcr / m ³ / d, specifically 8 kg CODcr / m ³ / d. Moreover, in the comparative example, it was necessary to replenish the granular sludge in the biological treatment tank 20 on the 32nd and 75th days from the start of water flow.

  1-4 Anaerobic biological treatment apparatus, 10 1-type biological treatment tank, 12 Draft tube, 14 Stirrer, 16 Carrier, 18 Submersible pump, 20 Biological treatment tank, 22 Solid-liquid separation unit, 24 Anaerobic granule, 26 Circulation line.

Claims (10)

From the start of anaerobic biological treatment, an anaerobic biological treatment apparatus that biologically treats organic matter-containing wastewater having a normal hexane extractant concentration of 100 mg / L or more and an SS concentration of 100 mg / L or more under anaerobic condition,
A one-tank biological treatment tank for anaerobically treating the organic matter-containing wastewater in the presence of a carrier;
A stirrer that stirs the organic matter-containing wastewater and the carrier in the one-tank biological treatment tank ,
The anaerobic biological treatment apparatus , wherein the carrier is a gel-like carrier, and the specific gravity of the carrier is greater than 1 .   The anaerobic biological treatment apparatus according to claim 1, wherein a pretreatment apparatus for separating fats and oils or suspended solids from the organic matter-containing waste water is not installed in a preceding stage of the one-tank biological treatment tank. The anaerobic biological treatment apparatus according to claim 1 or 2, wherein an anaerobic biological treatment is performed at an organic substance load of 10 kgCODcr / m ³ / d or more in the one tank type biological treatment tank. The biological treatment is performed under anaerobic conditions without diluting the normal hexane extractable substance concentration and SS concentration from the start of anaerobic biological treatment in the one tank type biological treatment tank . 4. The anaerobic biological treatment apparatus according to any one of 3 above.   The anaerobic biological treatment apparatus according to any one of claims 1 to 4, further comprising a pressurized levitation treatment apparatus downstream of the one-tank biological treatment tank. From the start of anaerobic biological treatment, an anaerobic biological treatment method for biologically treating an organic matter-containing wastewater having a normal hexane extractant concentration of 100 mg / L or more and an SS concentration of 100 mg / L or more under anaerobic condition,
In 1-vessel biological treatment tank the carrier is filled, seen including a biological treatment step of anaerobic biological treatment of the organic substance-containing waste water while stirring the organic matter containing wastewater and the carrier,
The anaerobic biological treatment method , wherein the carrier is a gel carrier, and the specific gravity of the carrier is greater than 1 .   The anaerobic biological treatment method according to claim 6, wherein a pretreatment step of separating oil or suspended matter from the organic matter-containing wastewater is not performed before the biological treatment step. The anaerobic biological treatment method according to claim 6 or 7, wherein in the biological treatment step, an anaerobic biological treatment is performed at an organic substance load of 10 kgCODcr / m ³ / d or more. The biological treatment is performed under anaerobic conditions without diluting the normal hexane extractable substance concentration and the SS concentration in the one-tank biological treatment tank from the start of the anaerobic biological treatment . The anaerobic biological treatment method according to any one of 8.   The anaerobic biological treatment method according to any one of claims 6 to 9, further comprising a pressurized flotation treatment step after the biological treatment step.