JPH07993A - Treatment of high-concentration organic sewage - Google Patents

Abstract

PURPOSE:To provide a method for treatment of org. sewage which efficiently treats the org. sewage with a simple treatment. CONSTITUTION:The high-concn. org. sewage subjected to sepn. of solid from liquid is introduced into a solubilizing vessel 1 where the org. sewage is made into lower molecule matter by org. nutrient bacteria and is inoculated with photosynthesis bacterium seed bacterial 3. The BOD materials made into the lower molecule matter are thus metabolized and removed. The sewage is then transferred into a photosynthesis bacterium vessel 4 where fine wooden pieces 5 are settled at about 15cm thickness on the front surface and are ventilated from the lower part of the vessel. The photosynthesis bacteria are propagated by the fine wooden pieces 5 while the low-molecular org. materials are subjected to a metaborization treatment. The treated water is thereafter transferred into a contact oxidation vessel 6 while the outflow of the photosynthesis bacteria is prevented by the fine wooden pieces 5. The activity of microorganisms, etc., by food chain is promoted by the contact materials stuck with the bacteria and the water is purified while the generation of the sludge is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating high-concentration organic wastewater, and more particularly to a treatment method for purifying high-concentration organic wastewater such as human waste and industrial wastewater mainly by photosynthetic bacteria.

[0002]

2. Description of the Related Art Today, when environmental purification is being called for, how to purify sewage efficiently and at low cost is an important issue. In particular, high-concentration organic sewage has problems in efficiency and cost of its treatment, and various treatment methods have been conventionally proposed.

For example, in Japanese Examined Patent Publication No. 47-45885, after excrement treatment of human sewage with its heterotrophic bacteria, the withdrawal liquid is transferred to a scarlet-colored sulfur-free bacterial culture layer, and stored in an aerobic atmosphere under dark or light conditions. Inoculate and culture the non-sulfur-free bacteria in
A method for treating human waste by purifying human waste by subjecting the separated liquid to chlorella culture treatment or activated sludge treatment after separating and obtaining bacterial cells has been proposed.

In Japanese Patent Publication No. 51-43311, a new strain of the red-sulfur-free bacterium, Rhodeseudomonas spueroides strain S, is inoculated into an organic wastewater, and aerobic and dark conditions or semi-aerobic conditions are obtained. A method for purifying organic wastewater by culturing under semi-dark conditions to purify organic wastewater has been proposed. In this purification method, the organic wastewater is transferred to the S strain culture tank,
Strain of purple non-sulfur bacteria is aerobic / dark conditions or semi-aerobic /
After inoculating in a semi-dark condition, culturing and proliferating, and harvesting the bacterial sludge, a part of the sludge is returned and cultured and used as a bacterial species.

Further, Japanese Patent Publication No. 15-15347 discloses that high-concentration organic wastewater having a low molecular weight is mainly used in dark
Under aerobic conditions, photosynthetic bacteria are inoculated, cultivated and proliferated to harvest and utilize the bacterial cells, and a part of the culture solution or bacterial sludge after bacterial cell growth is subjected to anaerobic / light conditions. A high-load organic sewage purification method has been proposed in which photosynthetic bacteria are activated by a return culture tank to continuously supply seed bacteria.

As described above, in the conventional method for treating organic sewage, a returning culture tank or the like is installed, and photosynthetic bacteria after the treatment tank are returned to the treatment tank to determine the bacterial cell concentration of the photosynthetic bacteria. keeping. In addition, the treated photosynthetic bacteria are harvested and used in a sedimentation tank. Furthermore, in the subsequent activated sludge treatment,
A sedimentation tank is installed to treat sludge. Therefore, they are effective as a method for treating large-scale organic wastewater such as industrial wastewater.

[0007]

However, in each of the conventional methods for treating organic wastewater, a return culture tank or the like is installed and photosynthetic bacteria are returned to reduce the bacterial cell concentration of the photosynthetic bacteria. Since it was held, the whole processing equipment became complicated, and it was difficult to keep the bacterial cell concentration, and as a small-scale organic wastewater treatment method, there was a problem in terms of cost as well as its operational aspect. There was a problem.

That is, in order to return the photosynthetic bacteria and maintain the bacterial cell concentration of the photosynthetic bacteria, considerable experience and technology are required, and a large-scale industrial wastewater treatment that can secure personnel with a wealth of experience and advanced technology. However, it was difficult to treat such small-scale organic sewage that is difficult to secure such personnel in terms of its operation. Moreover, in order to maintain the bacterial cell concentration of the photosynthetic bacteria, it is necessary to provide a return culture tank, which not only complicates the treatment process but also increases the cost, which is costly for treating small-scale organic wastewater. It was also a problem.

The present invention has been made in view of the above-mentioned problems, and it is a high-concentration organic substance with a simple treatment, without requiring advanced technology and experience, and without generating activated sludge. An object of the present invention is to provide a method for treating organic sewage that efficiently treats sewage.

[0010]

The gist of the constitution of the present invention is that a method for treating high-concentration organic wastewater mainly comprising photosynthetic bacteria is applied to a photosynthetic bacteria tank. This is a method for treating high-concentration organic wastewater in which a porous suspended matter having a low specific gravity is placed on the water surface of the high-concentration organic wastewater and aerated in the wastewater, whereby the above problems can be solved.

In this case, for example, in the photosynthetic bacteria tank,
After solid-liquid separation in advance, it is suitable to introduce high-concentration organic wastewater in which a high molecular weight substance is made into a low molecular weight by an organic trophic bacterium. Further, for example, wood particles or other porous floating materials can be used as the porous floating material. Further, there are various methods for the aeration, but it is appropriate to perform the aeration from the bottom of the photosynthetic bacteria tank. Further, the wastewater treated by the photosynthetic bacteria tank is further transferred to a contact oxidation tank, and contact aeration treatment is carried out using a cell-adhering contact material, whereby the tap water treatment can be easily completed.

[0012]

The present invention is configured as described above, and a porous suspended matter having a low specific gravity is placed on the surface of high-concentration organic wastewater introduced into a photosynthetic bacteria tank and aerated in the wastewater. As a result, photosynthetic bacteria are suspended in all photosynthetic bacteria tanks,
It is possible to assimilate the low molecular weight organic substance as the D source, and to grow and attach photosynthetic bacteria while purifying high-concentration organic sewage even in a porous suspension placed on the water surface. In addition, the porous suspended matter also plays the role of an effective support for dissolved oxygen by aeration, promotes the growth of photosynthetic bacteria, and when sewage flows out from the photosynthetic bacteria tank to the next treatment tank, those The photosynthetic bacteria are prevented from flowing out together with the sewage, and the concentration of the photosynthetic bacteria in the photosynthetic bacteria tank is constantly maintained.

Therefore, the organic sewage can be efficiently treated by a simple treatment without requiring advanced technology or experience and without generating activated sludge.

In this case, after the solid-liquid separation is carried out in advance in the photosynthetic bacterium tank, the high-concentration organic wastewater is introduced into the photosynthetic bacteria by introducing the high-concentration organic wastewater into which the high molecular weight substance has been reduced in molecular weight by the organic nutrient bacteria. It can be processed efficiently.

Further, by performing aeration from the lower part of the photosynthetic bacterium tank, it is possible to cause the porous suspended matter to efficiently contain air bubbles, and to serve as a more effective dissolved oxygen support for the porous suspended matter. Therefore, the sewage can be purified more efficiently.

Further, the sewage treated by the photosynthetic bacteria tank is transferred to the contact oxidation tank, and contact aeration treatment is carried out by the bacterial cell adhesion contact material. In this way, it is possible to form a complete food chain system by the bacterial cell-attached contact material in the contact oxidation tank, and a treatment that does not generate sludge at all is a simpler treatment and requires advanced technology and experience. Can be done without.

[0017]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a process chart showing the steps of an embodiment of the method for treating high-concentration organic wastewater according to the present invention. The first embodiment for treating piggery wastewater will be described below.

As shown in FIG. 1, in the method for treating high-concentration organic wastewater of this embodiment, the high-concentration organic wastewater received in the raw water pit is first transferred to the screen 1 which is a solid-liquid separator.
Solid-liquid separation by to remove as much solid matter as possible. As shown in Table 1 below, in this example, high-concentration organic wastewater, which is swine wastewater, had SS: 7200 ppm in the raw water pit,
COD: 3600ppm, BOD: 11000ppm,
This is solid-liquid separated by the screen 1, and SS: 21
00ppm, COD: 1600ppm, BOD: 6500ppm
Became.

The solid-liquid separated wastewater thus solid-liquid separated is transferred to the solubilization tank 2. In the solubilization tank 2, the solid-liquid separation wastewater is aerobically decomposed into low-molecular substances such as organic acids by the organic nutrient bacteria, and the solubilization tank 2 contains photosynthetic bacterial inoculum 3 (for example, 5). X10 ⁹ cells / ml) is inoculated in an amount of about 5 to 10% of the capacity of the tank, 6% in this example, and the low molecular weight BOD substance is assimilated and removed. The treatment in the solubilization tank 2 is performed by allowing the solid-liquid separation wastewater to stay for about 24 hours. Aeration was performed through the air diffuser 11 arranged at the bottom of the solubilization tank 2. As shown in Table 1 below, the solubilization tank 2
Treated wastewater is SS: 1500ppm, COD: 150
It became 0 ppm and BOD: 8900 ppm.

Next, the low-molecular-weight treated wastewater is transferred from the solubilization tank 2 to the photosynthetic bacteria tank 4, and wood particles 5 such as sawdust are put on the surface of the water as a porous suspended matter, and 1
Place it to a thickness of 0 to 20 cm. In this example, 2
A wood piece 5 of 5 mm was suspended in a thickness of 15 cm. An appropriate number of this photosynthetic bacteria tank 4 is installed according to the BOD concentration of the sewage introduced. In this example, two photosynthetic bacteria tanks 4 and 4 were connected in series.

Further, the wastewater is purified by aeration from the lower part of the photosynthetic bacteria tanks 4 and 4 in which the wood strips 5 are placed on the water surface. This ventilation is performed by the air diffuser 1 placed at the bottom of each photosynthetic bacteria tank 4, 4.
This is done by steps 1 and 11. That is, in the photosynthetic bacteria tanks 4 and 4,
Photosynthetic bacteria became turbid in all the tanks, as well as assimilating low molecular weight organic substances that are the source of BOD, and in the wood strips 5 placed on the water surface, photosynthetic bacteria proliferated and adhered,
Purifies highly concentrated organic wastewater. Further, the wood strip 5 functions as an effective support for dissolved oxygen by being aerated from below, and promotes the growth of photosynthetic bacteria. in addition,
The wood strips 5 prevent the photosynthetic bacteria from flowing out together with the sewage when the sewage flows out from the photosynthetic bacterium tank 4 to the contact oxidation tank 6 which is the next treatment tank. The concentration of photosynthetic bacteria is kept constant.

Therefore, the organic sewage can be efficiently treated with a simple treatment and without requiring a high level of skill and experience. In this case, photosynthetic bacteria tanks 4, 4
By returning the treated sewage of (1) to the solubilization tank 2 at an appropriate ratio, purification can be further promoted. In this example, about 20% was returned.

In the photosynthetic bacteria tanks 4 and 4, as the purification process progresses, that is, as the BOD concentration decreases, the photosynthetic bacteria grow and the activated sludge bacteria play an appropriate BOD concentration, for example, 500 ppm. The treatment process is set so that the treatment in the photosynthetic bacteria tanks 4 and 4 is completed when the purification treatment progresses to a certain degree.

To recapitulate a little briefly, in this example, as described above, two tanks of photosynthetic bacteria 4 and 4 are connected in series, and a wood strip 5 of 2 to 5 mm is put into the tank. Was floated and set to a thickness of about 15 cm, and aeration was performed in the dirty water by air diffusers 11 arranged at the bottoms of the photosynthetic bacteria tanks 4 and 4. 20% of the treated wastewater was returned to the solubilization tank 2. In addition, the sewage received is 2 in the photosynthetic bacteria tanks 4 and 4.
It was kept for 4 hours.

As shown in Table 1 below, in this example, the first
The treated sewage in the photosynthetic bacteria tank 4 in the second stage is SS: 900pp
m, COD: 1100 ppm, BOD: 1200 ppm, and the treated sewage in the second stage photosynthetic bacteria tank 4 is SS:
It became 200 ppm, COD: 880 ppm, and BOD: 480 ppm.

The sewage thus treated in the photosynthetic bacteria tanks 4 and 4 is passed through the filter layer of wood chips 5 such as sawdust, which is placed on the water surface, and the next catalytic oxidation tank 6 is provided. Transfer to. At this time, the photosynthetic bacteria are prevented from adhering to the wood strips 5 and flowing out to the next catalytic oxidation tank 6. Therefore, the concentration of the photosynthetic bacteria in the photosynthetic bacteria tanks 4 and 4 can be constantly maintained, and an efficient purification process can be performed.

The next catalytic oxidization tank 6 is connected in an appropriate number of stages, in this example, 5 tiers, and all the catalytic oxidization tanks 6, 6 ... Material 7, 7 ...
To form a complete food chain system and activate microorganisms and small animals to purify sewage. This contact oxidation tank 6,
In the process of 6 ..., the final stage and the front stage are returned at an appropriate ratio. In this example, it was decided to return about 40%. In this case, bacterial cell contact material 7,7
By increasing the number of ... in the latter stage, it is possible to promote the activity of microorganisms and small animals, and while completely preventing the generation of sludge, it is possible to purify the sewage to a water supply of BOD: 10 ppm or less. it can.

The above catalytic oxidation tanks 6, 6 ... Are ventilated through air diffusers 11, 11 ... Arranged at the bottoms thereof. Furthermore, in this embodiment, the air diffusers 11 and 11
By aeration by ... Dissolved oxygen was maintained at 1 ppm or more in all of the catalytic oxidation tanks 6, 6, the solubilization tank 2 and the photosynthetic bacteria tanks 11, 11.

However, the treatment status of the sewage at each stage of the above catalytic oxidation tanks 6, 6 ... In this example, as shown in Table 1 below, the treated water in the first stage catalytic oxidation tank 6 is treated. Is SS:
150ppm, COD: 520ppm, BOD: 350ppm,
The treated water in the second stage catalytic oxidation tank 6 is SS: 100 pp
m, COD: 350 ppm, BOD: 280 ppm, treated water in the third stage catalytic oxidation tank 6 is SS: 40 ppm, CO
D: 120 ppm, BOD: 100 ppm, treated water in the fourth stage catalytic oxidation tank 6 is SS: 20 ppm, COD: 100 p
pm, BOD: 30 ppm, treated water in the fifth stage catalytic oxidation tank 6 is SS: 5 ppm, COD: 90 ppm, BOD: 8 pp
It became m.

Since the wastewater is purified as described above,
The treated water in the catalytic oxidation tank 6 can be discharged as it is to a river or the like, and a sedimentation tank is not required, so that the entire wastewater treatment facility can be made compact and less expensive. In this example, the treated water in the catalytic oxidation tank 6 was introduced into the pillow settling tank 8, further sterilized in the disinfecting tank 9 and discharged. Moreover, in this example, the consumption of the photosynthetic bacterial inoculum could be reduced by about 60% as compared with the conventional circulation system provided with a culture tank. Therefore, it became possible to efficiently and inexpensively perform livestock manure treatment and small-scale drainage treatment, which were said to be difficult to treat, like the piggery drainage in this example.

[0031]

[Table 1]

Next, a second embodiment of treating wastewater from a marine product processing plant using the same equipment will be outlined. The wastewater from the fish processing plant with pH 7.3 and BOD of 13000 received in the raw water pit is subjected to solid-liquid separation with the screen 1, and the separated liquid is guided to the solubilization tank 2, where 8% of the photosynthetic bacterial inoculum 3 (5 × 1
⁰⁹ cells / ml). The treatment in the solubilization tank 2 and the treatments in the photosynthetic bacteria tanks 4 and 4 and the catalytic oxidation tanks 6 and 6 that follow the subsequent steps were carried out in exactly the same manner as in the first embodiment. As a result, the quality of the treated water in the final stage catalytic oxidation tank 6 was BOD: 8.7 ppm. Consumption of photosynthetic bacterial inoculum 3 is also higher than that of the conventional circulation system with a culture tank.
A decrease of about 55% was observed.

[0033]

As described above, since the porous suspended matter having a low specific gravity is placed on the surface of the high-concentration organic wastewater introduced into the photosynthetic bacterium tank and aerated in the wastewater, the photosynthetic bacteria are aerated. While photosynthetic bacteria become turbid in all tanks, as well as assimilating low-molecular organic substances that are the source of BOD, while purifying high-concentration organic sewage even in the porous suspension placed on the water surface , Photosynthetic bacteria grow and attach. In addition, the porous suspended matter also plays the role of an effective support for dissolved oxygen by aeration, promotes the growth of photosynthetic bacteria, and, when sewage flows from the photosynthetic bacteria tank to the next treatment tank, It prevents the water from flowing out with the sewage, and keeps the concentration of the photosynthetic bacteria in the photosynthetic bacteria tank constantly.

Therefore, the organic sewage can be efficiently treated by a simple treatment without requiring advanced technology or experience and without generating activated sludge.
As a result, livestock excrement treatment and small-scale wastewater treatment can be efficiently and inexpensively performed.

In this case, high-concentration organic wastewater is introduced into the photosynthetic bacterium tank by solid-liquid separation in advance, and then high-concentration organic wastewater in which high molecular weight substances are made into low molecular weight by organic nutrient bacteria is introduced, whereby the high-concentration organic wastewater is removed by photosynthetic bacteria. It can be processed more efficiently.

Further, by performing aeration from the lower part of the photosynthetic bacterium tank, it is possible to efficiently cause bubbles to be contained in the porous suspension, and the porous suspension is more effective as a support for dissolved oxygen. Can play the role of
It can be purified more efficiently.

Further, when the sewage treated by the photosynthetic bacteria tank is transferred to the contact oxidation tank and subjected to contact aeration treatment with the bacterial cell contact material, a complete food chain is obtained by the bacterial cell contact material of the contact oxidation tank. It is possible to form a system, and to perform a treatment in which no sludge is generated at all, with an even simpler treatment and without requiring advanced technology and experience.

[Brief description of drawings]

FIG. 1 is a process drawing showing a process of an embodiment of a method for treating high-concentration organic wastewater according to the present invention.

[Explanation of symbols]

 1 Screen 2 Solubilization Tank 3 Photosynthetic Bacteria Inoculum 4 Photosynthetic Bacteria Tank 5 Wood Chips 6 Contact Oxidation Tank 7 Cell Adhesion Contact Material 8 Pillow Settling Tank 9 Disinfection Tank 11 Diffuser

Claims (5)

[Claims] 1. A high-concentration organic wastewater treatment method for treating high-concentration organic wastewater mainly comprising photosynthetic bacteria, comprising a porous suspended matter having a low specific gravity on the water surface of the high-concentration organic wastewater introduced into the photosynthetic bacteria tank. A method for treating high-concentration organic sewage, in which the sewage is placed and aerated into the sewage. 2. The high-concentration organic wastewater according to claim 1, wherein the high-concentration organic wastewater is introduced into the photosynthetic bacterium tank after solid-liquid separation in advance, and then high-concentration organic wastewater in which a high molecular weight substance is made into a low molecular weight by organic nutrient bacteria is introduced. Processing method. 3. The method for treating highly concentrated organic wastewater according to claim 1, wherein wood particles are used as the porous suspended matter. 4. The method for treating high-concentration organic wastewater according to claim 1, 2 or 3, wherein the aeration is performed from the bottom of the photosynthetic bacteria tank. 5. The method according to claim 1, wherein the wastewater treated in the photosynthetic bacteria tank is transferred to a contact oxidation tank, and contact aeration treatment is carried out using a cell-attached contact material. Concentrated organic wastewater treatment method.