WO2014156216A1

WO2014156216A1 - Anaerobic treatment method

Info

Publication number: WO2014156216A1
Application number: PCT/JP2014/050228
Authority: WO
Inventors: 孝明徳富
Original assignee: 栗田工業株式会社
Priority date: 2013-03-27
Filing date: 2014-01-09
Publication date: 2014-10-02
Also published as: TW201446660A; CN105102378A; JPWO2014156216A1; KR20150137061A

Abstract

Provided is an anaerobic treatment method which enables the treatment of organic discharged water having a high solid concentration with high efficiency and at low facility cost. Raw water having a solid concentration of 1000 mg/L or more is treated in an acid generation vessel (1), then the treated water is supplied to a pH adjusting vessel (2) by means of a pump (P₁) to adjust the pH value of the water, and then the pH-adjusted water is allowed to pass through a reaction vessel (3), in which a fluid non-biological carrier (4) is filled, in an upward flow direction by means of a pump (P₂). A portion of outflowing water from the reaction vessel (3) is circulated into the pH adjusting vessel (2) as circulating water, and the remainder of the outflowing water is discharged to the outside of the system as treated water.

Description

Anaerobic treatment method

The present invention relates to an anaerobic treatment method in which a non-biological carrier having fluidity is filled in a reaction tank, a biological film is formed on the surface of the non-biological carrier, and the treated water is passed under anaerobic conditions. .

As an anaerobic treatment method for organic wastewater, a sludge blanket is formed by forming granular sludge with high density and high sedimentation in the reaction tank, and upwardly circulating organic wastewater containing soluble BOD. The UASB (Upflow Anaerobic Sludge Blanket) method is used, which performs high-load and high-speed processing by contacting with a high-pressure anaerobic sludge blanket. In this method, solid organic substances with a low digestion rate are separated and treated separately, and only soluble organic substances with a high digestion rate are processed at high speed with high load by anaerobic treatment using granular sludge with high anaerobic microorganism density. It is. As a development of this UASB method, EGSB (Expanded) is used to conduct anaerobic treatment at a higher load by passing water at a higher flow rate using a high reaction tank, deploying a sludge blanket at a higher deployment rate. Granule (Sludge Blanket) method is also carried out.

Anaerobic treatment using granular sludge, such as the UASB method and EGSB method, is a method of treating sludge containing anaerobic microorganisms in a granular state and growing it. This method can achieve a high sludge retention concentration compared to the treatment with a fixed bed or fluidized bed that holds sludge on the carrier, so that it can be operated at a high load, and surplus sludge from an already operating treatment system. It is an efficient anaerobic treatment method that can be started up in a short period of time.

However, in the method using these granular sludges, as described in Patent Document 1, precipitation, pressurization flotation, coagulation sedimentation, vibration are performed as described in Patent Document 1 when high concentration SS components are contained in the waste water. It was necessary to perform anaerobic treatment after removing solids with a screen, a rotary screen or the like. This is because, in the granule method such as UASB or EGSB, when a high concentration SS flows, the SS component pushes up the granule layer, and the granule flows out.

As anaerobic treatment of wastewater containing high concentration SS, there is anaerobic sludge digestion, but this is for the purpose of decomposing solids, so it usually requires a residence time of 10 days or more and requires a very large reaction tank. It becomes.

An anaerobic treatment method using a carrier includes a method using a fixed bed carrier. In Patent Document 2, when organic waste is subjected to methane fermentation treatment, methane is obtained by using immobilized microorganisms in which anaerobic microorganisms mainly composed of methane bacteria are supported on a carrier made of a synthetic resin material hydrophilically treated with ozone gas. A method for methane fermentation treatment of organic waste for fermentation is described.

However, when organic wastewater containing high-concentration SS is allowed to flow into the fixed bed of the carrier, there is a drawback that the SS component adheres to the surface of the carrier and becomes blocked.

On the other hand, in the method using a fluid non-biological carrier, it is possible to prevent the carrier from flowing out of the reaction tank by a mechanical method such as a screen, and the carrier surface can always be secured as a place for growing microorganisms. There is an advantage that it can be applied to low-concentration COD wastewater and wastewater in which granules are dismantled.

As a fluid non-biological carrier used for such treatment, Patent Document 3 comprises the following foam (I) and / or (II), and the carrier has a size of 1.0 to 5.0 mm. A flowable non-biological carrier is described in which the sedimentation rate of the carrier is 100-500 m / hr.
(I) A foam containing 30 to 95% by weight of a resin component mainly composed of a polyolefin resin and 5 to 70% by weight of a hydrophilizing agent for cellulose powder, the surface of which has a melt fracture state ( II) A foam containing 30 to 95% by weight of a resin component mainly composed of a polyolefin resin, 4 to 69% by weight of a hydrophilizing agent for cellulose powder, and 1 to 30% by weight of an inorganic powder, Foam having melt fracture state

JP-A-5-253594 JP 2003-260446 A JP2012-110843

As described above, when organic wastewater containing high-concentration SS is treated by an anaerobic treatment method using granules, high-concentration SS components cannot be allowed to flow into the granule tank. There was a problem that it was necessary to install a liquid separation facility, and the equipment cost of the entire process would increase. The anaerobic treatment method of Patent Document 3 does not describe treatment of organic wastewater having a high SS concentration.

An object of the present invention is to provide an anaerobic treatment method capable of treating organic wastewater with a high solid matter concentration efficiently and at low equipment costs.

The anaerobic treatment method of the present invention includes a step of treating an organic wastewater having a solid concentration of 1000 to 30000 mg / L in an anaerobic reaction tank having a fluid non-biological carrier.

In the present invention, it is preferable to pass the organic waste water through the reaction tank without removing the solid matter.

The size of the carrier is 1.0 to 5.0 mm, and the sedimentation speed of the carrier is 100 to 500 m / hr.

The hydraulic retention time (HRT) of the reaction vessel is preferably 1 to 120 hr.

The organic wastewater may be passed through the acid generation tank and then into the reaction tank.

The reaction vessel is preferably a complete mixing type reaction vessel or an upward flow type reaction vessel.

In the present invention, the organic waste water having a high solid concentration is passed through a reaction tank having a non-biological carrier, thereby allowing the non-biological carrier to flow in the anaerobic reaction tank and efficiently performing the anaerobic treatment. .

Since the non-biological carrier used in the present invention has a larger specific gravity and faster settling speed than granules, it can settle even in wastewater containing a high concentration of SS components. Since the generated gas and water flow are appropriately stirred and mixed, when the thickness of the biofilm is increased, the separation occurs naturally, and the floating and blockage of the flow path due to the enlargement of the biofilm can be avoided.

The SS component in the organic wastewater may also settle and accumulate inside the reaction tank, but it can be mixed using a fully mixed reaction tank, or in the case of an upward flow reaction tank, the rising flow rate of the liquid can be increased. By increasing the size, the accumulation of SS can be prevented.

∙ SS components in organic wastewater may also be hydrolyzed by microorganisms and converted to soluble components. In that case, the solubilized component is subjected to anaerobic biological treatment in the same manner as the originally included soluble component. By setting the hydraulic residence time in the anaerobic tank to 1 to 120 hours, the hydrolysis reaction efficiency of microorganisms of the SS component in the organic waste water is improved.

By using a fluid non-biological carrier that satisfies a size of 1 to 5 mm and a sedimentation speed of 100 to 500 m / hr, a sufficient amount of microorganisms are attached to the carrier, and then the carrier floats, flows out, and adheres. It is possible to prevent clogging and form a good fluidized bed, and to perform a stable and efficient anaerobic treatment.

It is a systematic diagram which shows the structure of the anaerobic processing apparatus used by the Example and the comparative example. It is a systematic diagram which shows the structure of the anaerobic processing apparatus used in the Example. It is a systematic diagram which shows the structure of the anaerobic processing apparatus used by the comparative example. It is a graph which shows the result of an Example. It is a graph which shows the result of a comparative example. It is a graph which shows the result of an Example. It is a graph which shows the result of a comparative example.

Hereinafter, embodiments of the present invention will be described in detail.

In the present invention, organic wastewater having a high solid matter concentration is passed through an anaerobic reaction tank filled with a fluid non-biological carrier, and a biological film is formed on the surface of the non-biological carrier to treat the organic waste water. .

The water to be treated in the present invention is a liquid having a high solid matter concentration and containing an organic substance that can be treated by anaerobic treatment by contacting with anaerobic microorganisms. The solid concentration is 1000 mg / L or more, for example, 1000 to 30000 mg / L, particularly 1000 to 5000 mg / L. The COD _Cr concentration in the organic waste water is preferably about 1000 to 60000 mg / L, particularly about 3000 to 15000 mg / L.

Such wastewater includes, but is not limited to, wastewater from food factories, organic wastewater from chemical factories, semiconductor factory wastewater, and the like.

When high-molecular components such as sugar and protein are contained in the water to be treated, as a pretreatment means for a reaction tank filled with a fluid non-biological carrier, as in the anaerobic treatment apparatus used in the examples described later. You may provide the acid generation tank which decomposes | disassembles a molecule | numerator into low molecular organic acids, such as an acetic acid and propionic acid.

In this case, the treatment conditions of the acid generation tank vary depending on conditions such as biodegradability of the water to be treated, but pH 5 to 8, preferably 5.5 to 7.0, temperature 20 to 40 ° C., preferably 25 to A temperature of 35 ° C. and HRT of 2 to 24 hours, preferably 2 to 8 hours is suitable.

If the low molecular weight is sufficiently advanced by such an acid generation tank, the treatment in the reaction tank filled with the fluid non-biological carrier in the subsequent stage proceeds well.

In the case of wastewater containing only compounds that can be directly used by methanogenic bacteria such as methanol and acetic acid, there is no need for an acid generator tank, and the treated water is directly passed through a reaction tank filled with a fluid non-biological carrier. Can do.

In the present invention, the reaction tank filled with the above-described fluid non-biological carrier and into which the water to be treated is passed is a fully mixed reaction tank using a stirrer or the like, an upward mixing in the tank with water flow and generated gas. A flow reaction tank or the like can be used.

The processing conditions in the complete mixing type reaction tank and the upward flow type reaction tank are not particularly limited as long as desired processing efficiency can be obtained. For example, the following conditions can be set.

<Completely mixed reaction tank>
Carrier filling rate: 10-30%
HRT: 1.0-24 hr
Tank load: 4.0 to 12.0 kg-COD _Cr / m ³ / day
Sludge load: 0.8-3.0kg-COD _Cr / kg-VSS / day
pH: 6.5-7.5
Temperature: 25-38 ° C
<Upward flow reactor>
Carrier filling rate: 10-80%
HRT: 1.0-24 hr
Ascending flow velocity (LV): 1.0-20m / hr
Tank load: 4.0 to 32 kg-COD _Cr / m ³ / day
Sludge load: 0.8-3.0kg-COD _Cr / kg-VSS / day
pH: 6.5-7.5
Temperature: 25-38 ° C

The fluid abiotic carrier used in the anaerobic treatment method of the present invention preferably has a size of 1.0 to 5.0 mm and a sedimentation speed of 100 to 500 m / hr.

If the size of the support is too large, the surface area per volume of the reaction vessel will be small, and if it is too small, the sedimentation rate will be slow and separation from the treated water will be difficult. The particularly preferred size of the carrier used in the present invention is 2.5 to 4.0 mm.

The size of the carrier is usually referred to as “particle size”. For example, in the case of a rectangular parallelepiped carrier, the length of its long side is referred to, and in the case of a cubic carrier, the length of one side thereof is defined. In the case of a cylindrical carrier, the larger one of the diameter and the height of the cylinder is meant. Further, in the case of a carrier having an irregular shape other than these shapes, when the carrier is sandwiched between two parallel plates, the interval between the plates where the interval between the plates becomes the largest is given.

In the present invention, the average size of the carrier may be 1.0 to 5.0 mm, preferably 2.5 to 4.0 mm, and all the carrier sizes are not in this range. Also good.

If the sedimentation speed of the carrier is too small, it will easily float due to water flow and generated gas, and will accumulate in the form of scum near the water surface. That is, in the case of a method using a non-biological carrier, a biofilm is formed on the surface, and a reaction in which gas is generated proceeds inside the biofilm, so that the apparent specific gravity of the carrier decreases with the formation of the biofilm. In consideration of the influence of this biofilm, it is necessary to determine the specific gravity and sedimentation rate of the carrier itself. Conversely, if the sedimentation rate of the carrier is too high, the contact efficiency with the water to be treated will be poor, and sufficient treatment efficiency will not be obtained, or solid matter will accumulate in the deposited layer of the carrier and the channel will be blocked. coming out. The preferred sedimentation rate of the carrier used in the present invention is 100 to 500 m / hr.

The sedimentation speed of the carrier is the amount of sedimentation by submerging the carrier in water (fresh water such as tap water), taking it into a graduated cylinder in water (fresh water such as tap water) This is a value obtained by measuring the distance. In the present invention, 10 to 20 carriers were measured, and the average value was taken as the sedimentation velocity.

The carrier used in the present invention is not particularly limited as long as the sedimentation rate and the carrier size satisfy the above-mentioned predetermined conditions and can retain bacteria. Foam, unfoamed or gel bodies are also possible. In particular, it is made of a foam of the following (I) and / or (II), and if it is made of such a resin foam, it is preferable in terms of easy adjustment of specific gravity and particle size.
(I) A foam containing 30 to 95% by weight of a resin component mainly composed of a polyolefin resin and 5 to 70% by weight of a hydrophilizing agent for cellulose powder, the surface of which has a melt fracture state ( Hereinafter, it may be referred to as “foam (I)”.
(II) A foam comprising 30 to 95% by weight of a resin component mainly composed of a polyolefin resin, 4 to 69% by weight of a hydrophilizing agent for cellulose powder, and 1 to 30% by weight of an inorganic powder, Has a melt fractured state (hereinafter sometimes referred to as “foam (II)”)

The polyolefin resin may not be a foam and may not contain a hydrophilizing agent as long as the sedimentation rate and the size of the carrier satisfy the above predetermined conditions. There is no restriction | limiting in particular also about the material of a gel body, Polyvinyl alcohol (PVA), polyethyleneglycol (PEG), acrylamide, polyacrylic acid, etc. are mentioned.

Here, melt fracture is generally known as a phenomenon in which irregularities are generated on the surface of a molded product during plastic molding (a state having no smooth surface). For example, in the extrusion molding of plastic material, when the internal pressure of the extruder becomes extremely high, the extrusion speed becomes extremely large, or the temperature of the plastic material becomes too low, irregular irregularities on the surface of the molded product This refers to a phenomenon in which surface gloss or surface gloss is lost.

Preferred resin components constituting the foams (I) and (II) are polyethylene (hereinafter sometimes simply abbreviated as “PE”), polypropylene (hereinafter simply abbreviated as “PP”). And ethylene-vinyl acetate copolymer (hereinafter sometimes simply referred to as “EVA”). These resins may be used alone or as a mixture appropriately combined. Further, the resin component constituting the foams (I) and (II) may be one obtained by adding another thermoplastic resin component to a polyolefin resin. As other thermoplastic resin components, polystyrene (hereinafter sometimes abbreviated as “PS”), polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyurethane, polyamide, polyacetal, polylactic acid, polymethyl methacrylate , ABS resin and the like.

Polyethylene is particularly preferable as the resin component constituting the foams (I) and (II), but a mixture of PE and other polyolefin resins, for example, a mixture of PE and PP, a mixture of PE and EVA, PE and It may be a mixture of PP and EVA, a mixture of PE, PP and PS, a mixture of PE, PP, EVA and PS, or a mixture obtained by further mixing other thermoplastic resins. Specifically, the composition ratio (weight ratio) of other thermoplastic resins including PE, PP, EVA, PS is 100, and other thermoplastic resins including PE: PP: EVA: PS = 100. It is preferably ˜60: 40 to 0:20 to 0:15 to 0. In order to improve the wear resistance of the carrier, it is preferable to contain 10% by weight or more of EVA in the resin component. These resin components may be recycled resins.

Examples of the cellulose-based powder as the hydrophilizing agent include wood powder, cellulose powder, hemp cellulose powder and the like, and sawdust, avicel, arbocel, paper powder, cellulose beads, microcrystalline cellulose, microfibrillated cellulose and the like are exemplified. However, it is particularly preferable to use wood flour. Any of these may be used alone, or two or more of them may be mixed and used in an arbitrary ratio.

The shape of the hydrophilizing agent is spherical, elliptical, wedge-shaped, whisker-shaped, fibrous or the like, but other shapes may be used. The particle size of the hydrophilizing agent is 200 mesh pass product, preferably 100 mesh pass product, more preferably 40 mesh pass product.

In the present invention, the hydrophilizing agent has a role of imparting a water permeation function to the foam having closed cells. For this purpose, the hydrophilizing agent is desirably exposed or protruded from the surface of the foam. . Here, exposure means that part of the surface of the hydrophilizing agent appears on the foam surface, and protrusion means that part of the hydrophilizing agent protrudes from the foam surface. . That is, being exposed or protruding means that the whole or part of the hydrophilizing agent is buried in the foam and a part of the surface of the hydrophilizing agent appears on the foam surface, or It means a state in which a part of the hydrophilizing agent protrudes from the foam surface.

Examples of the inorganic powder used for the foam (II) include barium sulfate, calcium carbonate, zeolite, talc, titanium oxide, potassium titanate, and aluminum hydroxide, and barium sulfate is particularly preferable. Any of these inorganic powders may be used alone, or two or more kinds of inorganic powders may be used.

Even if the specific gravity calculated from the apparent volume is smaller or larger than the above lower limit, the settling velocity defined in the present invention may not be satisfied. The specific gravity obtained from the apparent volume of the foam is a value (unit: g / ml) obtained by measuring 30 ml of the foam in an apparent volume in a 50 ml graduated cylinder and calculating the weight. It shall be shown. This is because the foams (I) and (II) have a melt-lacquered state on the surface, and it is very difficult to measure the true volume. Hereinafter, the specific gravity obtained from the apparent volume of the foam is simply referred to as “specific gravity”.

Foams (I) and (II) are prepared by melting and kneading the above-mentioned polyolefin resin, hydrophilizing agent, and further inorganic powder, and further foaming a mixture obtained by melting and kneading the foaming agent. It can be manufactured by cutting into a size.

Examples of foaming agents include sodium bicarbonate (sodium bicarbonate) and azodicarbonamide. A foaming agent is not restricted to these, A chemical foaming agent, a physical foaming agent, etc. are mentioned.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.

[Examples 1 to 3, Comparative Examples 1 to 4]
By using the anaerobic treatment apparatus shown in FIG. 1, food wastewater having a COD _Cr concentration of 5000 mg / L, SS: 1500 mg / L, TN: 250 mg N / L, TP: 30 mg / L, pH: 5.0 is discharged. A water flow test was conducted as raw water.

In this anaerobic treatment device, after processing the raw water with acid production tank 1, and pH adjusted feed to pH adjustment tank 2 by pump P _1, the flowable non-biological carrier 4 pH adjustment water by a pump P ₂ The packed reaction tank 3 is treated by passing water upward. A part of the effluent water from the reaction tank 3 is circulated to the pH adjustment tank 2 as circulating water, and the remainder is discharged out of the system as treated water. Sodium hydroxide is added to the acid generation tank 1 and the pH adjustment tank 2 as an alkaline agent for pH adjustment. 1A and 2A are pH meters, 1B and 2B are stirrers, and 3A is a screen.

The treatment conditions of the acid generation tank 1, the pH adjustment tank 2, and the reaction tank 3 were as follows.
<Acid production tank>
Capacity: 5L
HRT: 4 hours
pH: 6.5
Temperature: 35 ° C

<PH adjustment tank 2>
Capacity: 1L
pH: 7.0
<Reaction tank>
Capacity: Approximately 7.5L (diameter 15cm, height approximately 50cm)
HRT: 6 hr
Ascending flow velocity (LV): 3-4m / hr
pH: 7.0
Carrier filling rate: 40%

The specifications of the flowable non-biological carrier used are as shown in Table 1. Polyolefin resin is used as the constituent material of the foam and polyethylene is used as the hydrophilizing agent. Wood powder was used, and barium sulfate was used as the inorganic powder. Each carrier has a cylindrical shape, and the size of the carrier is the height of the column.

The amount of treated water was about 30 L / day, and at the start of the treatment, the reaction tank 3 was filled with a carrier with microorganisms attached at a filling rate of 40%.

FIG. 4 (Example 1) and FIG. 5 (Comparative Example 4) show the changes over time in the COD _Cr concentration of Example 1 and Comparative Example 4.

<Discussion>
In Examples 1 to 3, the carrier can be stably processed without causing a blocking phenomenon due to the floating and fixing of the carrier. (The COD _Cr concentration change is representatively shown in FIG. 4 only for Example 1. As for Examples 2 and 3, it was recognized that the COD _Cr concentration change was almost the same as Example 1.) Comparison In Example 1, the carrier floated due to SS and became unprocessable. In Comparative Example 2, the carrier was fixed and blocked by SS, making it impossible to process. In Comparative Example 3, the carrier floated due to SS and became unprocessable. In Comparative Example 4, no clogging due to floating and sticking of the carrier was observed, but as shown in FIG. 5, the COD _Cr concentration of the treated water was higher than that of FIG. Has fallen.

[Example 4]
As shown in FIG. 2, the pH adjustment tank 2 was not installed, and the reaction tank was the following fully mixed reaction tank 3 ′ (microorganisms were previously attached to the carrier as in Examples 1 to 3). The food wastewater was treated in the same manner as in Example 1 except that. 3C is a pH meter, and 3B is a stirrer. FIG. 6 shows the change over time in the COD _Cr concentration.
In the complete mixing type, if a carrier with a low sedimentation rate is used, SS adheres and floats, so the concentration of treated water deteriorates during long-term operation. If a carrier with a high sedimentation rate is used, the carrier flows uniformly in the reaction vessel. Therefore, it is a problem that much energy is required for stirring.
<Completely mixed reaction tank>
Capacity: Approximately 7.5L
HRT: 6 hr
pH: 7.0
Carrier filling rate: 40%
Temperature: 35 ° C

[Comparative Example 5]
As shown in FIG. 3, the food wastewater was treated in the same manner as in Example 1 except that the reaction vessel was the following granule reaction vessel 3 ″. 4 'is a granule, and 3D is a gas-solid-liquid separator (GSS). FIG. 7 shows the change over time in the COD _Cr concentration. In Comparative Example 5, the granule was raised by SS and flowed out of the reaction tank, the sludge in the reaction tank was reduced and the treatment capacity was lowered, so the water quality deteriorated.
<Granule tank>
Capacity: Approximately 7.5L
HRT: 6 hr
pH: 7.0
Temperature: 35 ° C
Granule: 4L of beer factory UASB equipment granule introduced

Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application No. 2013-066782 filed on March 27, 2013, which is incorporated by reference in its entirety.

1 Acid generation tank 2

pH adjustment tank

3, 3 ′, 3 ″ reaction tank 4 Fluid non-biological carrier

Claims

An anaerobic treatment method comprising a step of treating an organic waste water having a solid concentration of 1000 to 30000 mg / L in an anaerobic reaction tank having a fluid non-biological carrier, wherein the carrier has a size of 1.0. An anaerobic treatment method, wherein the carrier has a sedimentation speed of 100 to 500 m / hr.
The anaerobic treatment method according to claim 1, wherein the organic waste water is passed through the reaction tank without being subjected to a solid substance removal treatment.
3. The anaerobic treatment method according to claim 1, wherein the hydraulic residence time in the reaction tank is 1 to 120 hours.
The anaerobic treatment method according to any one of claims 1 to 3, wherein the organic waste water is passed through the acid generation tank and then passed through the reaction tank.
The anaerobic treatment method according to any one of claims 1 to 4, wherein the reaction vessel is a complete mixing type reaction vessel.
The anaerobic treatment method according to any one of claims 1 to 4, wherein the reaction vessel is an upward flow type reaction vessel.
The anaerobic treatment method according to claim 1, wherein the COD Cr concentration of the organic waste water is 1000 to 60000 mg / L.
5. The anaerobic treatment method according to claim 4, wherein the treatment conditions of the acid generation tank are pH 5 to 8, temperature 20 to 40 ° C., and hydraulic residence time 2 to 24 hours.
6. The anaerobic treatment method according to claim 5, wherein the treatment conditions of the complete mixing type reaction vessel are as follows.
Carrier filling rate: 10-30%
Hydrological residence time: 1.0-24 hr
Tank load: 4.0 to 12.0 kg-COD Cr / m 3 / day
Sludge load: 0.8-3.0kg-COD Cr / kg-VSS / day
pH: 6.5-7.5
Temperature: 25-38 ° C
The anaerobic treatment method according to claim 6, wherein treatment conditions of the upward flow type reaction tank are as follows.
Carrier filling rate: 10-80%
Hydrological residence time: 1.0-24 hr
Ascending flow velocity (LV): 1.0-20m / hr
Tank load: 4.0 to 32 kg-COD Cr / m 3 / day
Sludge load: 0.8-3.0kg-COD Cr / kg-VSS / day
pH: 6.5-7.5
Temperature: 25-38 ° C
2. The anaerobic treatment method according to claim 1, wherein the carrier comprises the following foam (I) and / or (II).
(I) A foam containing 30 to 95% by weight of a resin component mainly composed of a polyolefin resin and 5 to 70% by weight of a hydrophilizing agent for cellulose powder, the surface of which has a melt fracture state ( II) A foam containing 30 to 95% by weight of a resin component mainly composed of a polyolefin resin, 4 to 69% by weight of a hydrophilizing agent for cellulose powder, and 1 to 30% by weight of an inorganic powder, Foam having melt fracture state