JPH04326990A - Sewage treatment plant and bacterial bonded and living biological shelf - Google Patents

Abstract

PURPOSE:To purify lakes and marshes, a basin or the source of water supply or to treat sewage such as industrial waste water or household waste water and, especially, to purify sewage with BOD of 3000ppm or less to obtain purified water with BOD of 5ppm or less. CONSTITUTION:A jet pump 1 whose air take-in port is extended above the surface of the water is arranged and a biological shelf 5 on which bacteria are bonded and live is arranged within the arrival range of the water stream from the jet pump 1 and bacteria efficiently decomposing org. matter in sewage are charged in a treatment tank 2 if necessary. The biological shelf 5 is constituted by forming a string material composed of fine yarns made of polypropylene or polyvinylidene chloride into a desired shape and arranging the same to a frame body 10.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The purpose of this invention is to purify lakes, ponds, water source ponds, etc., and to treat wastewater such as industrial wastewater and domestic wastewater.In particular, it purifies wastewater with a BOD of 3000 ppm or less to 5 ppm or less. The purpose is to

0002

BACKGROUND OF THE INVENTION Various sewage treatment methods have been employed heretofore. For example, the activated sludge method, biofilm method, septic tank, microbial injection method, etc. have been adopted.

0003

[Problem to be solved by the invention] In the activated sludge method, BOD
It is not possible to purify sewage with a low concentration of 20 ppm or less, and excess sludge is produced.

[0004] The biofilm method has a small treatment volume and cannot purify a large amount of water in a short period of time, so it can only be used for wastewater treatment in very limited places.

[0005] A septic tank cannot purify to a BOD of 10 ppm or less, and its purification ability cannot be said to be sufficient.

[0006] In the microorganism injection method, the microorganisms do not settle completely, so they wash away when it rains heavily, and the microorganisms conventionally used have little effect at temperatures below 10 degrees Celsius. Another problem is that oil is difficult to decompose, and when a disinfectant flows in, most of the microorganisms are killed.

[0007] There is also a purification method that combines a submersible pump and an oxygen increase device, but this method cannot cope with sudden changes in water.

[0008]

[Means for solving the problem] In other words, a large amount of water can be purified in a short period of time, and the ability to purify winter pond water when the water temperature is below 10 degrees does not decrease, and it is also resistant to oil and disinfectants. Effective and reduces BOD5p without producing excess sludge
A purification method that can purify to below pm is optimal.

[0009] Therefore, the sewage treatment method according to the present invention is as follows:
A jet pump with an air intake extending above the water surface is installed underwater, and a biological shelf with microorganisms attached and inhabited is installed within the reach of the water flow of the jet pump. Microorganisms that efficiently decompose organic matter are introduced into the treatment tank as needed.

[0010] Furthermore, the biological shelf for attaching and inhabiting microorganisms according to the present invention is one in which thin threads of polypropylene or vinylidene chloride are curled into a string shape and arranged in a frame. be.

[0011]

[Operation] A jet pump is installed in the wastewater, and air is taken in from the air intake port extending above the water surface to dissolve a large amount of oxygen into the water. Adjust operating hours.

[0012] Then, this pump creates a water stream with a length of about 50 m, and this water stream reaches the biological shelf to process and purify the wastewater. Preferably, the flow rate of water passing through the biological shelf is adjusted to about 6 m/min.

[0013] In order to increase the surface area, the biological shelf is constructed by curling thin threads of polypropylene or vinylidene chloride into a string shape and placing them on a frame so that water flow can pass through them without resistance. .

[0014] Adjust the amount of oxygen supplied to the biological shelf so that surplus organisms do not occur, and add useful microorganisms to the biological shelf twice a year depending on the water quality.
Keep the plankton in good condition by adding more than once. For example, ensure stable reproduction of Melosira granulata.

[0015] Examples of microorganisms that adhere to and live on the biological shelf include aerobic bacteria, anaerobic bacteria, Zoog.
lea, actinomycetes with algicidal effects, lactic acid bacteria, and zooplankton yeasts can be used.

[0016] In order to decompose pesticides, Zooglea
Genus ramigra and filipendula
, actinomycetes, and fungi isolated from soil with a lot of pesticides.
It uses bacteria that degrade phenolic compounds, pesticides, herbicides, and fungicides.

[0017] By using low-temperature bacteria that proliferate at low temperatures, the purification effect can be achieved even below 5 degrees Celsius.

Yeast, bacteria, and rotifers are used to decompose fats and oils, detergents (ABS), and organic compounds.

[0019] A mixed culture of 489 types of useful microorganisms isolated and cultured from golf-shaped regulating ponds, heavily polluted river bottoms, and lake sludge, and whose effects have been confirmed.
08m/l, as a guideline 1 for 1000m3
Mix at a rate of 0 liters.

[0020]

[Embodiment] Next, an embodiment of the sewage treatment system according to the present invention will be explained based on the drawings.

Reference numeral 1 denotes a jet pump disposed in the water of the sewage treatment tank 2. The jet pump 1 is connected to an air intake port 3 whose opening extends above the water surface. A biological shelf 5 is arranged in front of the discharge port 4 of the jet pump 1. Microorganisms are attached to and inhabit the biological shelf 5, and the biological shelf 5 is provided within the reach of the water flow from the jet pump 1 so that the microorganisms can treat wastewater.

[0022] The biological shelf 5 is preferably one that allows bacterial cells to easily adhere to it, has a large surface area relative to its size, and allows water flow to pass through it without resistance. As for the material, a material such as a string-like body 6 made by curling thin threads of polypropylene or vinylidene chloride is preferable. However, it is only necessary that the bacterial cells can attach thereto, and the material and shape are not limited in any way.

For example, as shown in FIG. 5, this string-like body 6 is made into a length of 1 with a slight gap between both ends.
A ring-shaped body 8 with a diameter of about 6 cm is formed by fixing it to a center rod 7 of about m length, and a large number of these are fixed to one center rod 7 at appropriate intervals to form a single biofilm subgrade rod 9. shall be.

[0024] Note that the center rod 7 may not be provided, and the ring-like bodies 8 may be interconnected to form a single biofilm roadbed rod 9. In this case, 3 to 10 mm in the center
Make sure there is a gap of about

The biofilm subgrade rods 9 thus constructed are fixed to a metal frame 10 using a number of suitable methods, as shown in FIG. The size of the frame 10 is a cube with one side of 1 m, and about 25 to 50 biofilm subgrade rods 9 are arranged therein. Adjacent biofilm subgrade rods 9 should be separated by at least 5 cm.

The frame 10 may be made of plastic, in which case the weight 11 is fixed to the bottom of the frame 10. Note that the biological shelf 5 is not limited to this size, and the size and number of biofilm subgrade rods 9 are also not limited to this example, but may vary depending on the inflow water and the conditions of the installation location. , can be changed as appropriate.

The biological shelf 5 may also have a frame 10 with both ends of string-like bodies 6 fixed to the frame 10, as shown in FIG. Further, as shown in FIG. 6, only one end of the frame body 10
It may also be fixed to a windsock shape. Moreover, it can also be formed into a donut shape or the like. Note that the arrows indicate the direction of water flow.

Next, an experimental example using the sewage treatment method according to the present invention will be explained.

``Experiment Example 1'' ``Experiment Purpose'' Regarding various data showing the state of sewage treatment,
Measurements should be taken to confirm the effects and also to compare untreated ponds.

"Experimental Method" [Experimental Pond] The experiment was carried out in a pond of the following size as shown in FIG. Long side approx. 45m, short side approx. 40m, surface area approx. 1600m
2. Average water depth 1.5m

[Experiment period] The experiment was conducted for about half a year from August to February.

[Experimental equipment] The following equipment was placed in the water of the experimental pond as shown in FIG. Jet pump (3
4 biological shelves (of the type shown in Figure 2, side length 1 m)

[Bacterial cells used] 20 liters (bacteria number 108
/ml)/1600m2

``Experiment Contents'' Water was sampled from a certain point in the experimental pond every two months, various analyzes were conducted, and the data was compared with that of the control pond (a part of the pond mentioned above separated by a vinyl sheet). I made a comparison.

"Experimental Results" The experimental results were as follows.

Water sampling date August 10th October 10th
Sun December 10th February 10th Contrarian Pond February 10th
Day Water temperature (degrees) 32
20 8 5
5 Transparency (cm)
10 50 100 or more
100 or more 20 pH
8.7 9.0
8.7 8.5
8.7 COD mg/l
300 110 3
3 102
BOD mg/l 20
5 3 2
15 T-N mg/l
28 8.2 12.0
4.5 26
T-P mg/l 35
28 18 0.06
20 cl mg/l
35 15 10
10 3
8 Oil content (ppm) 15
7 1 1
15 ABS mg/l
11.0 1.5
0.7 0.2
9.0

"Consideration" The following can be said from the above experimental results. ■ The visibility has increased from 10cm to over 100cm, but the control pond has no improvement at 20cm. ■ Oil removal rate is 93%. ■ The removal rate of TN is 98%. ■ The removal rate of T-P is 82%. ■ BOD removal rate is 90%. ■ ABS removal rate is 98%.

``Experiment Example 2'' ``Experimental Purpose'' To confirm the effect of the decomposition of pesticides and to compare with untreated ponds.

"Experimental Method" [Experimental Pond] The experiment was conducted in a pond with an area of approximately 300 tsubo and a depth of 1.2 m.

[Experiment period] September 10th to September 20th
I followed it for 0 days.

[Experimental equipment] The following items were placed in the water of the experimental pond. Two jet pumps (2 horsepower) and two biological shelves (of the type shown in Figure 2, side length 1 m).

[Bacteria used] 4 liters (108 bacteria/ml)

``Experiment Contents'' Water was sampled from a certain point in the experimental pond every 3 to 4 days, and various measurements were carried out according to the Environment Agency method, and a control pond (a part of the pond mentioned above separated by vinyl sheets) was used. We compared the data with

"Experimental Results" The experimental results were as follows.

Water sampling date September 10th September 14th September 17th September 20th Control pond September 20th
TPN (ppm) 3.0 1
．． 5 0.3 0.02
2.7 CAT (ppm)
3.5 1.0 0.0
2 0.001 3.
0 MEP (ppm) 5.0
2.0 0.01 -
1.2

"Discussion" The following can be said from the above experimental results. ■ The Environment Agency guideline value for TPN (Daconyl (fungicide)) is 0.4ppm or less, and the Ministry of Health and Welfare guideline value is 0.04p.
pm or less, but the measured values were well below them. ■ The Environment Agency guideline value for CAT (simazine (herbicide)) is 0.03ppm or less, and the Ministry of Health and Welfare guideline value is also 0.03ppm.
pm or less, but the measured value was well below that. ■ The Environment Agency guideline value for MEP (Sumithion (insecticide)) is 0.1ppm or less, and the Ministry of Health and Welfare guideline value is 0.03p.
pm or less, but the measured values were well below them.

[0047]

Effects of the Invention As described above, according to the sewage treatment method of the present invention, a jet pump with an air intake extending above the water surface is disposed underwater, and microorganisms are removed within the reach of the water flow of the jet pump. Since we have installed a biological shelf with biomass attached and inhabited, it is possible to dissolve a large amount of oxygen into the water, and the aerobic biofilm method can be carried out efficiently, making it possible to purify a large amount of water in a short period of time. , even if the inflow volume increases rapidly, it can be adequately handled. By completing the food chain, sludge can be reduced by 30 to 80% compared to the current level.

[0048] Furthermore, since microorganisms that efficiently decompose organic matter contained in wastewater are introduced into the treatment tank as necessary, the treatment effect can be reliably increased for all types of wastewater. . Purification can be performed even at low temperatures, such as 10 degrees Celsius or lower. In addition, oil can be efficiently decomposed, and even if a disinfectant flows in, the disinfectant can be decomposed.

On the other hand, according to the biological shelf for attaching and inhabiting microorganisms according to the present invention, fine threads of polypropylene or vinylidene chloride are curled to form a string shape, and this is arranged in a frame. As a result, the structure makes it easy for bacterial cells to attach and inhabit, and the bacterial cells do not flow out even in heavy rain, and the contact surface area can be increased, so biological treatment can be performed efficiently.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the sewage treatment system of the present invention.

FIG. 2 is a perspective view showing an embodiment of a biological shelf used in the present invention.

FIG. 3 is a perspective view showing another example of a biological shelf used in the present invention.

FIG. 4 is a perspective view showing another example of a biological shelf used in the present invention.

FIG. 5 is a front view of the biofilm subgrade rod used in the embodiment of FIG. 2;

FIG. 6 is a conceptual plan view of an experimental pond in Experimental Example 1.

[Explanation of symbols]

1 Jet pump 2 Processing tank 3 Air intake 4 Discharge port 5 Biological shelf 6 String-like body 7 Center rod 8 Ring-shaped body 9 Biofilm subgrade rod 10 Frame body 11 Weight

Claims (3)

[Claims] [Claim 1] A jet pump with an air intake extending above the water surface is disposed underwater, and a biological shelf on which microorganisms are attached and inhabit is disposed within the reach of the water flow of the jet pump. Sewage treatment method. 2. The sewage treatment system according to claim 1, wherein microorganisms that efficiently decompose organic matter contained in the sewage are introduced into the treatment tank as necessary. 3. Curling thin threads of polypropylene or vinylidene chloride into a string shape,
A biological shelf for attaching and inhabiting microorganisms, characterized in that this is arranged in a frame.