JPS6150678B2 - - Google Patents

Description

[Detailed Description of the Invention] In the conventional organic wastewater purification method, pollutants are oxidized and decomposed by the action of aerobic bacteria in an aeration tank, and then supernatant water and grown aerobic bacteria are mixed in a settling tank. The sludge is separated by gravity into sludge, and the supernatant water is discharged to the outside, while a portion of the sludge is returned to the aeration tank as a nutrient source for aerobic bacteria, and the remainder is temporarily stored in the sludge storage tank. It was disposed of as industrial waste.

The present invention involves adding soil bacteria to excess sludge and supplying air in a sludge digestion tank that also serves as a storage tank.
It promotes the digestion of sludge while maintaining the activity of aerobic bacteria, and when there is a significant shortage of nutrients for the growth of aerobic bacteria in the wastewater flowing into the aeration tank, this excess sludge is supplied to improve the aerobic conditions in the aeration tank. In addition to compensating for the decrease in bacteria and nurturing sources and maintaining good sewage purification, the system ultimately digests excess sludge, which was previously disposed of, in the sewage purification equipment and prevents it from being discharged outside. The present invention relates to a method for purifying organic wastewater, and will be specifically explained below based on the attached drawings.

The wastewater from which oil and dust have been removed by a pretreatment device (not shown) flows into a flow rate adjustment tank 2 through an inflow pipe 1 .

A fumarole pipe 4 in which a large number of fumarole holes 3 are bored is arranged at the bottom of the flow rate adjustment tank, and the fumarole pipe 4 is connected to a first blower 5 installed on the flow rate adjustment tank 2. There is.

Aerobic bacteria in the wastewater temporarily stored in the flow rate adjustment tank 2 multiply while oxidizing and decomposing organic pollutants by the air blown out from the fumaroles 3.

The sewage is pumped through a sewage pump 6 installed on the flow rate adjustment tank 2, passes through a flow rate adjustment device 7 and a sewage pipe 8, and then passes through an inner cylinder 10 installed in the center of the next stage aeration tank 9.
flows into.

The lower end of the inner cylinder 10 expands in a downward truss shape slightly above the bottom surface of the aeration tank 9, and similarly, the upper end expands upward in a truss shape almost at the dirty water surface.

Slightly above the upper end expanded portion 11 of the inner cylinder 10, there is a removal plate 13 which has a downward conical shape, is coaxial with the expanded portion 11, and has appropriate protrusions 12 fixed on its lower surface. , is attached and suspended from the shaft of a motor 14 disposed at the center of the upper surface of the aeration tank 9.

By this rotation of the removal plate 13, the sewage in the upper part of the inner cylinder 10 is violently scattered diagonally upward and outward, and at the same time it comes into contact with air over a wide area, and at the same time sucks the sewage from the lower end of the inner cylinder 10. The wastewater inside 9 circulates as shown by the arrow.

In this way, the sewage is sufficiently aerated in the aeration tank 9, oxidized and decomposed by the air and aerobic bacteria, and purified.The aerobic bacteria that proliferate become sludge, which passes through the turbid water pipe 15 to the next settling tank 16. flows into the rectifying tube 17 at the top of the tube.

While the turbid water flowing into the straightening tube 17 descends slowly, the sludge is separated by gravity and settles to the bottom of the settling tank 16.

The settled sludge is collected at the center of the bottom by curved sludge collecting blades 19 installed on the bottom surface of the settling tank 16 and rotated at a slow speed by a motor 18 on the settling tank 16.

The supernatant water from which sludge has been removed flows from a drain gutter 20 provided at the upper part of the outer surface of the rectifier cylinder 17 through a water pipe 21 to a disinfection tank 22 at the next stage, where it is sterilized and then discharged from a drain pipe 23. Ru.

The sludge settled in the sedimentation tank 16 is passed through the first sludge pipe 25 by the first sludge pump 24 connected to the center of the bottom, and a part of it is used as a nutrient source for replenishing aerobic bacteria and growing them. , is returned to the inner cylinder 10 of the aeration tank a, and the remainder is sent to a sludge digestion tank 26 which also serves as a sludge storage tank, which will be described below.

At the bottom of the digestion tank 26, there are many fumaroles 27...
A fumarole pipe 28 is provided, and the fumarole pipe 28 is
is a second blower 29 disposed on the digestion tank 26
It is connected to the.

Inside the digestion tank 26, a required number of leaching boxes 30, each having a cylindrical shape with a bottom and reaching closer to the bottom plate than near the top plate, are arranged, and each leaching box 30 has a large number of pores 31...
... has been drilled.

A leaching bag 32 made of, for example, canvas is attached to the inner surface of each leaching box 30, and the inside of the leaching bag 32 is filled with soil 33 in which soil bacteria have propagated, so that the soil bacteria can leach into the sludge. It's getting old.

The aerobic bacteria in the excess sludge stored in the digestion tank 26 are kept active while being digested using the sludge as a nutrient source by the air blown out from the fumaroles 27. , facilitated by the cooperation of leaching soil bacteria.

This activated sludge is produced when organic substances in the sewage flowing into the above-mentioned sewage purification device are significantly reduced and aerobic bacteria and growth nutrients in the aeration tank 9 are insufficient.
From time to time, the second slurry pump 34 disposed on the digestion tank 26 returns the slurry to the flow rate adjustment tank 2 via the second slurry pipe 35 .

In the method of the present invention, as described above, the settling tank 1
Excess sludge discharged from 6 is stored in the digestion tank 26 while maintaining the activity of aerobic bacteria and digested with the cooperation of soil bacteria, and is reused as necessary, so the composition of the inflowing sewage is significantly reduced. Even if the amount of aerobic bacteria and growth nutrients in the aeration tank 9 fluctuates, the amount of aerobic bacteria and growth nutrients in the aeration tank 9 can be maintained at an appropriate level, and not only can wastewater be purified well at all times, but also surplus sludge can be used in the process of recycling.
Since the sludge is gradually digested, it has the advantage that the sludge can be disposed of without being discharged to the outside.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of an apparatus for carrying out the method of the present invention, and FIG. 2 is an enlarged longitudinal sectional view of an infusion box. 1... Inflow pipe, 2... Flow rate adjustment tank, 3... Fumarole, 4... Fumarole pipe, 5... Blower, 6... Sewage pump, 7... Flow rate adjustment device, 8... Sewage pipe, 9
... Aeration tank, 10 ... Inner cylinder, 11 ... Expansion section, 1
2... Projection, 13... Removal plate, 14... Motor, 15... Turbid water pipe, 16... Sedimentation tank, 17...
Straightening tube, 18...Motor, 19...Sludge collecting blade, 2
0... Drain gutter, 21... Water pipe, 22... Disinfection tank, 23... Drain pipe, 24... Sludge pump, 25
...sludge pipe, 26...digestion tank, 27...fumarole,
28... Fumarole pipe, 29... Blower, 30... Leach box, 31... Pore, 32... Leach bag, 33...
Soil, 34...Sludge pump, 35...Sludge pipe.

Claims (1)

[Claims] 1 After first storing organic sewage in a flow rate adjustment tank and adjusting the flow rate, it is led to the next stage aeration tank and aerated, and the sludge produced by oxidizing and decomposing pollutants through the action of aerobic bacteria is transferred to the next stage. The sludge is allowed to settle in the sedimentation tank of the stage, and only the supernatant water is sterilized and discharged. A part of the settled sludge is returned to the aeration tank, and the remaining part of the settled sludge is transferred to the sludge digestion tank that also serves as sludge storage. ,
Soil bacteria are supplied from a leaching box placed in the digestion tank and filled with soil in which soil bacteria have propagated, and brought into sufficient contact with air to digest the sludge while maintaining the activity of aerobic bacteria. When there is a lack of nutrients for aerobic bacteria in the inflowing sewage, the activated sludge in the digestion tank is returned to the flow rate adjustment tank to maintain good sewage purification at all times, and the excess sludge is removed to the outside. An organic wastewater purification method characterized by digestion without discharge.