JPS6328496A - Treatment of organic sanitary sewage - Google Patents

Abstract

PURPOSE:To permit easy and efficient removal of org. matter, denitrification and dephosphorization with simple stages by providing an aerobic filter bed tank in which a porous contact material consisting of hydrated calcium silicate is packed and an anaerobic filter bed tank. CONSTITUTION:Org. sanitary sewage such as cattle dung, living waste water or sewage is introduced into the aerobic filter bed tank 3 in which the porous contact material contg. calcium silicate having 50-90% voids as the main constituting material is packed. The sewage is then treated by a biological membrane method and is thereby subjected to the removal of the org. matter, dephosphorization and nitrification. The treated water subjected to the nitrification is introduced into the anaerobic filter bed tank 5 and is subjected to the biological denitrification. The above-mentioned porous contact material is the molding obtd. by adding a foaming agent such as Al powder to a slurry contg. the siliceous raw material and calcareous raw material as essential raw materials and subjecting the slurry to a hydrothermal reaction treatment at and under a high temp. and high pressure or the crushed matter obtd. by crushing said molding. The removal of the org. matter, the denitrification and the dephosphorization are easily and efficiently executed by such simple stages.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for treating organic wastewater such as livestock urine wastewater, household wastewater, and sewage. This method has been devised to easily and efficiently perform dephosphorization and denitrification as well as removal of chemical oxygen demand (chemical oxygen demand) through simple steps.

<Conventional techniques and their problems> Livestock urine II': Organic sewage such as water, miscellaneous wastewater, and sewage is the cause of enrichment and catabolism that induces "blue water" and "red tide" in lakes and inland seas. Become. Conventionally, there are various ways to treat such organic wastewater, such as the activated sludge method, the water sprinkler bed method, and the rotating disk contact method, but the immersion iA 1p bed method is superior from many points of view, such as installation area, treatment efficiency, and maintenance management. It is often adopted. In this immersion bed method, an aerobic hearth tank is filled with contact material, and sewage is poured into it and aerated to form a biofilm on the surface of the contact material, and the sewage is purified by the action of the microorganisms of this organism 11a. The idea is to do so. In addition, gravel, plastic pieces, honeycomb tubes, etc. are used as contact materials for this immersion hearth method.

However, although the above-mentioned soaking method can remove organic matter, it cannot sufficiently remove nitrogen compounds, phosphoric acid, and phosphates (hereinafter referred to as phosphorus), so the treated water is discharged into a closed water system. In some cases, this can lead to eutrophication, causing great damage to fisheries and other industries. Therefore, when organic wastewater is treated by the immersion hearth method, it is necessary to separately perform denitrification and dephosphorization.

Therefore, biological denitrification is generally used along with soaking or bed methods. This biological denitrification property is achieved by installing an anaerobic filter bed tank after the aerobic filtrate in the immersion hearth method, and the aerobic water is oxidized by nitrite bacteria and nitrate bacteria in the immersion hearth method.
I4. N02-N and No3-N, which have changed from ``-N, are reduced to N2 gas by denitrifying bacteria in an anaerobic mulch under anoxic conditions.

However, in order to sufficiently perform this denitrification, in the aerobic hearth tank in the immersed hearth method, N02--N of N) 14ゝ-N,
Oxidation to 803--N, that is, nitrification, must be carried out sufficiently, but as nitrification progresses, 211 decreases, so neutralization treatment with an alkaline agent in an aerobic hearth tank is required, and management and equipment In addition to the problem of complicating the process, the use of chemicals also imposes a large economic burden.

Conventionally, such denitrification is followed by phosphorus. Calcium salts,
There are two methods: one is to precipitate and remove phosphate as a phosphate by reaction with metal salts such as aluminum and iron, and the other is to crystallize and dephosphorize as hydroxyapatite in an alkaline region in the presence of calcium, but both methods require a dephosphorization device. Alternatively, separate equipment called a dephosphorization tank is required. In addition, the former sedimentation removal method generates a lot of sludge and is difficult to dewater, making treatment difficult, and the use of chemicals poses a large economic burden, while the latter crystallization dephosphorization method Although the amount of sludge generated and the amount of chemicals used are small, it is difficult to control the 11η treatment process, which creates conditions that promote crystallization, such as calcium concentration adjustment, pH adjustment, and decarboxylation.
There are problems with management and equipment complexity.

At present, when treating organic wastewater, there are three methods: organic matter removal (soaking is the bed method), denitrification, and dephosphorization.
The process is essential.

Here, an example of such organic wastewater treatment process is shown in the eighth section.
This will be explained with reference to the figures. As shown in the figure, organic sewage is subjected to primary treatment in the screen settling tank 1 and vibration 17i+2 to remove floating matter and sediment, and then diluted with water in the dilution tank 3, and then processed by the immersion hearth method. In the air tank 4, nitrification is carried out sufficiently while removing organic matter and adjusting pt+ using an alkaline agent. Next, methanol is added and stirred in a stirring tank 5, and then denitrification is performed in an anaerobic tank 6.
Organic matter is removed again in the aerobic tank 7 and sent to the dephosphorization process.

The dephosphorization process includes decarboxylation by adding sulfuric acid in decarboxylation tank 8,
A pretreatment process consisting of pH adjustment by adding gypsum and slaked lime in the pH adjustment tank 9, and a step of precipitating CuCO3 etc. with precipitate 1O, and a crystallization dephosphorization process in which phosphorus is removed as hydroxyapatite in the dephosphorization Jtg11. Consisting of phosphorus,
The treated water that has undergone this dephosphorization process is disinfected in a disinfection tank 12 and then drained.

As described above, conventional treatment of organic wastewater required a large number of facilities and sophisticated operational management.

In view of the above circumstances, an object of the present invention is to provide a method for treating organic wastewater that can easily and efficiently perform organic matter removal, denitrification, and dephosphorization in simple steps.

Means for Solving the Problems> As a result of various studies to achieve the above object, the present inventors have found that a certain type of composition consisting of calcium silicate eternity or a biofilm method for organic wastewater has been developed. The present invention was completed based on the findings that a treatment with nitrification creates a favorable environment for microorganisms to live in, crystallizes and removes phosphate ions, and maintains a pH suitable for nitrification.

The structure of the present invention is such that organic matter such as livestock urine sewage, domestic wastewater, sewage, etc. A process in which nitrified wastewater is introduced and treated using the biofilm method to remove organic matter, dephosphorization, and nitrification, and a process in which nitrified treated water is introduced into an anaerobic ash bedpan to perform biological denitrification. It is characterized by having the following.

The configuration of the present invention will be explained in detail below.

To explain more specifically, the porous contact material used in the present invention is produced by adding a foaming agent such as aluminum powder to a slurry whose main raw materials are silicic raw materials and calcareous raw materials, and then hydrothermalizing the slurry with a foaming agent such as aluminum powder under high temperature and high pressure. A molded product obtained by reaction treatment or a crushed product obtained by crushing this molded product with a porosity of 50 to
90% slurry, or a slurry whose main raw materials are silicic raw materials and calcareous raw materials, is subjected to a hydrothermal reaction treatment under high temperature and high pressure, and if necessary, pulverized, and the resulting powder is granulated or molded by adding air bubbles. The porosity of the granulated or molded product is 50 to 90.
%belongs to.

Here, calcium silicate hydrate is prepared by combining a silicate raw material and a calcareous raw material at a predetermined CaO/SiO2 molar ratio (0.5 to 2.0
The required pressure and
It is obtained by curing under high temperature and high pressure, and silicic raw materials include powders such as silica stone, silica sand, cristobalite, amorphous silica, diatomaceous earth, ferrosilicon dust, and white clay, and calcareous raw materials include quicklime, slaked lime, and cement. Examples include powders such as. The calcium silicate hydrate thus obtained is one or more selected from the group consisting of tobermorite, xonotlite, CSH gel, phoshagite, gyrolite, hillebrandite, and the like. Among these, tobermorite, zonolite, and CSH gel are particularly preferred because they have a high pH buffering ability and a large specific surface area of 20 to 400 rn''/g.

The porous contact material used in the present invention has a porosity of 50 to 90%, but when this porosity is obtained during the production of calcium silicate eternity, a foaming agent is added to a slurry of silicic material and calcareous material. After adding a metal foaming agent such as aluminum powder or a foaming agent such as an AE agent, a hydrothermal reaction treatment may be performed at high temperature and high pressure. Here, the metal foaming agent generates gas through a chemical reaction, and its usage ratio varies depending on the amount of bubbles and water entrained in the slurry, but can be derived from the chemical reaction equation. Specific examples of foaming agents include resin soaps, saponins, synthetic surfactants, hydrolyzed proteins, and polymeric surfactants, which mainly introduce air bubbles physically through surfactant action. There are cases in which foam is generated simply by mixing with raw materials and stirring, and cases in which stable foam is created using a special stirring tank or foaming device, and this foam is measured by volume and mixed with raw materials. There is.

When using such a foaming agent, it is necessary to test the stability of the foam and then determine the amount to be added. Further, when a calcium silicate hydrate with a small porosity is obtained, if it is a molded product, the porosity can be adjusted by pulverizing it and then manually removing air bubbles during the granulation or molding process.

In other words, an aqueous solution of a polymer resin sizing agent such as an acrylic resin emulsion is added to powdered calcium silicate hydrate, and if necessary, a foaming agent is added to form a feL 7Fa suspension, which is then granulated using a pan pelletizer. It can be done by molding or molding.

As for the method of drying here, either natural drying or heat drying may be employed. Further, here, as the powdered calcium silicate hydrate, a powder obtained by crushing a material formed by manually forming voids as described above may be used. In addition, when forming a porous contact material with a high porosity, molding may be used.

The method for treating organic sewage according to the present invention is that organic sewage that has been subjected to primary treatment in an aerobic hearth chamber filled with a porous contact material to remove floating matter and sediment is not aerated or diluted. By passing water through the reactor, the removal of organic matter by the biofilm method, the removal of phosphorus, and the nitrification of NIl and ``-N'' are performed simultaneously.

Treated water containing N113--N is introduced into an anaerobic itotoba tank, and a hydrogen donor such as methanol is added to remove NO□-N by denitrifying bacteria in an aerated anaerobic state.

Biological denitrification is performed by pumping Na5-N into N2 gas.

Here, the porous contact material filled in the aerobic hearth tank has crystals of calcium silicate hydrate or minute irregularities on the surface of the kel, so microorganisms are easily immobilized and biofilms are formed. Lactic acid and butyric acid are easy to form and are decomposition products of organic matter (microbial metabolites).

Mitigates the pH drop caused by lower fatty acids such as acetic acid, and helps microorganisms reach 21! ! A slightly alkaline pH state of 8 to 9 can be stably created. Therefore, in the aerobic hearth of the method of the present invention, the activities of bacteria and protozoa that contribute to the decomposition of organic matter, and of rabbit nitrate bacteria and nitrate bacteria that perform nitrification become active, making it possible to process at high loads. Even if the introduced fi' organic activated sewage has a high concentration such as urine sewage from general pigsty, dilution is not necessary.

In addition, dephosphorization in an aerobic hearth furnace is due to the following effects.

The porous contact material in the aerobic hearth tank supplies Ca2° necessary for crystallization of calcium hydroxyapatite from the crystal or gel surface of the calcium silicate ethos forming the porous contact material, and also increases the pl+buffer of the contact material. Even if the PL+ of wastewater is low and its value fluctuates, the pH will always be around 8.
Since a stable state of ~9 is created, phosphate ions in the wastewater react with Ca2 and crystallize on the surface of the contact material in the form of calcium hydroxyapatite. At this time, the voids in the porous contact material act to disturb the unidirectional flow of wastewater and to moderate the flow velocity on the surface of the contact material, so that calcium hydroxyapatite is precipitated by phosphate ions and Ca''. In addition, although this porous 71 contact material does not contain "crystal seeds" similar to calcium phosphate or calcium hydroxyapatite, it has an adsorption ability, so in the early stage of water flow, the produced calcium It adsorbs hydroxyapatite, and after that, its surface has a structure suitable for nucleation of calcium hydroxyapatite, and the nucleus of calcium hydroxyapatite is formed in the microscopic voids and pores.

When the porous contact material after sewage treatment is observed with a scanning electron microscope, a large number of microorganisms are seen to be settled and living inside the pores and on the surface of the crystals, and amorphous crystals are also observed. It was identified as calcium hydroxyapatite using an X-ray microanalyzer.

As is clear from this, the pores of the porous contact material
Voids have a great effect on microbial implantation and dephosphorization, and the porous contact material used in the present invention has a porosity of 50 to 9.
0%, preferably 60 to 80%, is desirable for microbial implantation and dephosphorization. The porosity of this porous contact material is 50
If the porosity is less than 90%, the specific surface area will be small, making it difficult for microorganisms to settle and the phosphorus removal rate will be low.On the other hand, if the porosity exceeds 90%, floating will occur due to the introduction of water into the tank and aeration. As the temperature increases, the strength decreases significantly, and the durability of the pl+ buffering capacity and the phosphorus removal effect also deteriorates, which is not preferable.

Further, the size of the porous contact material used in the present invention also has a large effect on the phosphorus removal performance. If the diameter of the contact material is smaller than 0.5cm, it will be easily clogged with SS and crystallized crystals, so it cannot be used for a long period of time. Both are unfavorable as they result in a decrease in Therefore, the porous contact material is 0.5 to 1
A size of 0 mm is desirable.

Here, an example of the method for treating organic wastewater according to the present invention is shown in FIG. 1 and FIG. 7g2.

'f, The example shown in Figure 1 is an example in which an anaerobic hearth tank is placed next to an aerobic hearth tank. As shown in the figure, the organic sewage that has been primarily treated by the screen settling basin 1 and the vibrating sieve 2 is
The porous contact material is introduced into an aerobic tank (aerobic hearth tank) 3 filled with the porous contact material, where organic matter removal, dephosphorization, and nitrification are performed. Next, stir! f! 4 and methanol or organic sewage is added to the anaerobic tank (anaerobic hearth tank) 5
The water is denitrified and then drained through a re-aerobic tank 6 and disinfection jfI7.

FIG. 2 is an example of a circulating treatment process. As shown in the figure, organic sewage that has been primarily treated in the screen settling tank 1 and the vibrating sieve 2 passes through the stirring tank 13 and the anaerobic tank 14, and then is introduced into the aerobic tank 15 filled with porous contact material. Circulated to stirring M113. This performs organic matter treatment, dephosphorization, and denitrification. This treated water is drained through a re-anaerobic tank I6 and a disinfection tank 7.

As is clear from the above, according to the method for treating organic wastewater according to the present invention, the number of steps is significantly reduced compared to the conventional method, and operation and management are also facilitated.

Furthermore, the porous contact material used in the present invention also has the function of adsorbing heavy metals, so if heavy metals are contained in organic wastewater, they will be removed together with organic matter and phosphorus.

Note that the porous contact material used in the method of the present invention can be reused as a silicate lime fertilizer and a soil improvement material, which is very economical.

Examples of manufacturing porous contact materials and test examples showing the effects of the present invention are shown below.

(Production example of porous contact material) (IIcsH gel contact material 4.ffffl parts of silica powder, 2 parts by weight of quicklime powder, 1 part by weight of slaked lime powder, and 3 parts by weight of feeding portland cement (CaO/SiO2 molar ratio = 1.5 ) and 0.008 parts by weight of metal aluminum powder was added to 7 parts of water to make a slurry.Then, this slurry was poured into a mold, left to stand for 4 hours, and then removed from the mold using a rotating brush. After pulverizing with a pan pelletizer to a particle size of 5 to 10 o++n, the material was hydrothermally treated in an autoclave at 150°C and 5 atm for 10 hours to obtain a porous contact material.The porosity of this contact material was 70%. Ta.

(2) Tobermorite contact material 5 parts by weight of silica powder, 2 parts by weight of quicklime powder, and 3 parts by weight of ordinary Portland cement (Can/Sin molar ratio = 0
．． A slurry was prepared by adding 7 parts by weight of water to a mixture obtained by adding 0.008 parts by weight of metallic aluminum powder to 8). This slurry was poured into a mold, left to stand for 4 hours, and then removed from the mold, which was then hydrothermally treated in an autoclave at 180° C. and under 10 atmospheric pressure for 10 hours. The obtained molded product was crushed using a crusher and sieved to a particle size of 5 to 10 mm to obtain a porous contact material. The porosity of this material was 75%.

(3) Zonotlite contact material silica powder and quicklime powder at a Gap/5i02 molar ratio of 1.
10 times the solid component.
fM water to form an aqueous slurry, which was subjected to water treatment in an autoclave at 210° C. and under 20 atm with stirring for 10 hours. The acrylic resin emulsion (solid content 10%) was added to 4! Double the amount of Ilc was added, kneaded, and then granulated, dried and solidified at 110°C, and sieved to a particle size of 5 to 10 ml to obtain a porous contact material.

The porosity of this material was 73%.

(4) Tobermorite contact materials with various porosity In the manufacturing method shown in (2) above, various tobermorite contact materials are obtained by changing the addition ratio of combined aluminum powder and water as shown in Table 1. Ta.

Table 1 (Test Example 1) As shown in Figure 3, 200X filled with porous contact material
1st mill 101 and 200X1 of 150X310mm
In a second tank 102 of 50 x 290 mm, treated water of collagen sewage passed through a steel vibrating sieve with q4<0.3+nmφ, which had been subjected to solid-liquid separation, was passed in an upward flow.
The performance of various porous contact materials was investigated by performing aeration at 500 i/min from below each of the 101° and 102 pores.

Here, the above manufacturing example fil, +21, (:ll
Each of the porous contact materials manufactured in
1゜+02 and passed primary treated water at a flow rate of 10 liters/mouth to test examples -1゜＾-2, A-3, respectively.
And so.

For comparison, comparative examples B-1 and B were prepared using commercially available Halas, pumice 1 limestone, and polypropylene with a particle size of 5 to 10 mm as contact materials instead of the porous contact material, respectively.
-2, B-3, and B-4.

2 to 3 months 1 for stiff test examples A-1 to A-4 and comparative examples B-1 to G-4! At the same time, the continuous lightness of the treated water, p
H, BOD and T-P (total phosphorus), N114”-
The concentrations of N, N02-N, NO, and J-N were each measured four times, and the averages are shown in Table 2.

7jIJ2 Table 1 As shown in this result, BOD volume load 1.0kg/day・
BOD removal rate in high load processing of ml is comparative example 7
Whereas the removal rate was 7 to 87%, the method of the present invention showed a high removal rate of 95% or more. Further, the removal rate of phosphorus was 25% or less in the comparative example, which was hardly removed, but the method of the present invention had a high removal rate of 90% or more. Furthermore, in order to perform denitrification in the next step, organic nitrogen and N1-14
Is it necessary to nitrify "-N to NO, -N or Ni12-N? According to the method of the present invention, nitrification is completely achieved even with a high-load treatment with a volumetric load of NH4"-N of 0.4 kg/TodoM. The process is progressing, and it is now possible to completely use nitrogen in the next process. On the other hand, in the comparative example, 10 to 30% Nl
Since +4''-N remains, even if biological denitrification is added afterwards, this remaining N114''-N will be flushed out as is.

Test Example 2) Using the same experimental apparatus as in Test Example 1, collagen-subprocessed water was treated with various treatment materials shown in Production Example (4) to test the difference in purification depending on the porosity of the contact material. Note that other conditions were the same as in Test Example 1. This result is similar to test example 12
Table 3 shows the average of the results of four measurements over a period of ~3 months.

Table 3 As shown in Table 3, when the porosity of the contact material is 50% or more, the effects of BOD removal and phosphorus removal are large and nitrification progresses sufficiently. Note that if the porosity exceeds 90%, the material will flow out of the casserole due to the floating phenomenon when water is passed through it, and at the same time, the strength will decrease significantly.

From this result, the pore structure of the contact material is extremely important for increasing the contact opportunity between the contact material and organic water and for allowing microorganisms to settle in the pores and voids. It is also extremely important for the crystal growth of calcium hydroxyapatite that crystallizes at the same time, and greatly contributes to the phosphorus removal effect.

Example 1 Example 1 In this example, A as shown in FIGS.
A concrete sewage treatment system consisting of six treatment chambers (-F) was used. Here, A, B, and F are aerobic hearth tops, and 8 and B are porous contacts mainly composed of tobermorite with a grain size of 5 to 15 mm produced in the same manner as in Production Example (2) above. The material also has a particle size of 5 to 8fflIT for F.
1 of similar tobermorite contacting materials, each with an aeration tube 110aN110 below for aeration.
c is provided. These diffuser cylinders 110a N110
c is connected to an air pump l13 via an air pipe III and an air adjustment valve 112. Processing [C] is a stirring tank to which methanol is supplied from a methanol tank 114. In addition, D and E are anaerobic hearth tanks, and inside these are commercially available anthracite with particle sizes of 5 to 10.
Filled with mm.

In such a sewage treatment apparatus, the primary treated water of pigsty sewage was passed through the sewage inlet pipe 115 at a rate of tfLm of 6002/day, and the treated liquid was discharged from the discharge pipe 116. In addition,
The flow rate of methanol added in processing chamber C is as follows: 1. H!
It is the 7th.

The treatment was carried out under these conditions for about 6 months, and the results were as follows: ρ)1. Transparency, BOD, SS,
TP and TN (total nitrogen) were measured respectively. The results are shown in FIG. As is clear from the figure, according to this example, organic matter, phosphorus, and nitrogen in the pigsty wastewater are reliably removed over a long period of time.

Example 2 In this example, a concrete sewage treatment apparatus consisting of six treatment chambers GL as shown in FIG. 6 was used. Here, ■ and J are aerobic hearth cassettes, and these cassettes are filled with a contact material whose main structure is tobermorite with a grain size of 5 to 10 mm, which was produced in the same manner as in Production Example (2) above. At the same time, there is an aeration cylinder 120 below it for aeration.
a, 120b are arranged. These diffuser cylinders 120
a and 120b are connected to an air pump 123 via an air pipe +21 and an air adjustment valve 122. On the other hand, treated MG and H are anaerobic hearths filled with commercially available anthracite with a particle size of 5 to 15n++n, and sewage is introduced from the sewage inlet pipe +25, and methanol is supplied from the methanol tank +24. It looks like it's going to be 4 years old. The wastewater that has passed through these G and H is treated in the aerobic tanks I and J, and then from the treatment tank to the circulating water inlet pipe +27
and is connected to the G processing tank via a flow rate pump 128. After K, there is a re-anaerobic ML, which is filled with anthracite similar to G and H.

In such a sewage treatment equipment, the primary treated water from the sewage inlet pipe 125 is passed through at a flow rate of 6002/E] and the circulation from sewage to G is set at 54001/day, and the nitrogen concentration in the sewage is Since the denitrification effect was small due to the high BOD source in the wastewater, 0.217 molar of methanol as a hydrogen donor was supplied to the anaerobic tank G. In this way, the wastewater was treated for about 6 months,
At this time, the pll, transparency, BOD, SS, T-P and T of the next treated water and the discharged treated liquid from the treated discharge pipe 126
-N was measured respectively. The results are shown in FIG. As is clear from the figure, according to this example, organic matter in the pigsty wastewater.

Phosphorus and nitrogen are removed reliably over a long period of time.

Here, let us examine the results of Example 1.2 in more detail.

As shown in FIGS. 5 and 7, in Example 1.2, γ
Purification has progressed from about 4 weeks after the water was introduced, and the quality of the treated water has been stable since the 8th week. Here, when the measurement results of the water quality of the treated water after the 8th distance in Examples 1 and 2 are averaged, the results are as shown in Table 4.

As shown in Table i4, in both Examples 1 and 2, BOD, SS
Of course, high removal rates were also shown for T-P and T-N, resulting in extremely high-quality processing results.

Regarding heavy metals, the inflow sewage and discharged treated water at the 200th week in Example 1 were measured, and the results are shown in Table 5.

As shown in Table 5, more than 90% of the heavy metals copper and zinc contained in the pigsty wastewater were removed by the treatment of this example.

<Effects of the Invention> As specifically explained above in conjunction with test examples and examples, the method of the present invention efficiently removes organic matter, nitrogen, and phosphorus through simple and easy treatment without requiring complicated steps. It is easy to maintain and manage, and it is also possible to treat highly concentrated sewage such as domestic silkworm urine sewage and factory wastewater with a high load, making it possible to downsize and simplify the treatment equipment. can be converted into Moreover, according to the method of the present invention, copper.

Heavy metals such as zinc and lead can also be removed at the same time.

Furthermore, the porous contact material whose treatment capacity has decreased due to long-term use can be reused as a silicate lime fertilizer and a soil improvement material, which is economical.

[Brief explanation of the drawing]

Figures 1 to 7 are related to the present invention, Figures 1 and 2 are process diagrams showing an example of a method for treating organic wastewater, Figure 3 is an explanatory diagram showing the apparatus used in the test example, 41 Ne1 is an explanatory diagram showing the sewage treatment equipment used in the first example, Figure 5 is an explanatory diagram showing the results of the first example, and Figure 6 is an explanatory diagram showing the sewage treatment equipment used in the second example. FIG. 7 is an explanatory diagram showing the results of the second example, and FIG. 8 is a process diagram showing the organic wastewater treatment process according to the prior art. In the drawing, 3. I5 is an aerobic hearth tank, and 5, l=I is an anaerobic hearth tank.

Claims (1)

[Scope of Claims] 1) An aerobic hearth tank filled with a porous contact material mainly composed of calcium silicate with a porosity of 50 to 90% is filled with organic matter such as livestock urine wastewater, miscellaneous wastewater, and sewage. A process in which nitrified wastewater is introduced and treated using the biofilm method to remove organic matter, dephosphorization, and nitrification, and a process in which nitrified treated water is introduced into an anaerobic filter bed tank to perform biological denitrification. A method for treating organic wastewater, characterized by comprising: 2) The porous contact material is a molded product obtained by adding a foaming agent such as aluminum powder to a slurry whose main raw materials are silicate raw materials and calcareous raw materials, and subjecting the mixture to hydrothermal reaction treatment at high temperature and high pressure, or this molded product. The method for treating organic wastewater according to claim 1, which is a crushed product obtained by crushing organic wastewater. 3) The porous contact material is made by granulating or granulating a slurry whose main raw materials are silicic raw materials and calcareous raw materials by subjecting it to hydrothermal reaction treatment at high temperature and high pressure, and pulverizing the resulting powder if necessary. The method for treating organic wastewater according to claim 1, which is a molded granule or molded product. 4) Calcium silicate hydrate is one or more selected from the group of tobermorite, xonotlite, CSH gel, fosagite, gyrolite, and hillebrandite. The method for treating organic wastewater according to item 2 or 3.