JP2002066595A - Treating equipment for sludge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide equipment for sludge which can perform a solubilization treatment of sludge, and which is simple, safe, and saves energy by destroying cell membranes of microorganisms in sludge. SOLUTION: The treating equipment for sludge is provided with a low- pressure tank 2 in which sludge can air-tightly be enclosed, a preliminary low- pressure tank 3 having larger capacity than that of the low-pressure tank 2, a vacuum pump 12 which decompresses the preliminary low-pressure tank 3, and a valve 24 which connects the low-pressure tank 2 openably and closably with the preliminary low-pressure tank 3. The cell membranes of microorganisms in sludge are destroyed by opening the bulb 24, connecting the preliminary low-pressure tank 3 with low-pressure tank 2 which are decompressed, and then rapidly lowering the pressure of the low-pressure tank 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for treating sludge, and more particularly to a method for solubilizing sludge in a simple, safe and energy-saving manner by destroying cell membranes of microorganisms in sludge by decompression. The present invention relates to an apparatus for treating sludge.

[0002]

2. Description of the Related Art Conventionally, an activated sludge treatment method in which organic wastewater such as sewage is biologically treated with microorganisms and discharged as surplus sludge has been adopted. In this activated sludge treatment method, surplus sludge is discharged according to the amount of organic wastewater to be treated, so that it becomes necessary to treat the surplus sludge. In order to solve such problems as a rise in operating costs and a decrease in final disposal sites when disposing of the excess sludge, a solubilization treatment of the sludge in which the excess sludge is not discharged out of the water treatment system has been proposed.

[0003] As a method of solubilization treatment, a method of solubilizing sludge by ultrasonic waves, a method of heating sludge to a high temperature and applying high pressure to decompose and solubilize cell walls, and a method of using an alkaline chemical such as aqueous sodium hydroxide solution. A method of decomposing cell walls with ozone and the like have been proposed.

[0004]

However, the conventional method of solubilization using ultrasonic waves has a problem that it is difficult to change cells into a fragile state. There is a problem that energy consumption increases and processing costs increase. further,
The method using an alkaline chemical may cause secondary pollution due to the chemical, and the method using ozone has a problem that it is difficult to handle ozone safely.

The present invention has been made in view of the above-mentioned problems of the conventional method for treating sludge, and it has been found that the solubilization of sludge can be carried out simply, safely and energy-saving by destroying the cell membrane of microorganisms in the sludge. It is an object of the present invention to provide a sludge treatment device that can be used.

[0006]

Means for Solving the Problems To achieve the above object, a sludge treatment apparatus of the present invention comprises a decompression tank capable of sealing and sealing sludge, and depressurizing the decompression tank to remove microorganisms in the sludge. And a decompression means for destroying the cell membrane.

The sludge treatment apparatus of the present invention is capable of expanding the microbubbles in the cell wall of microorganisms and rapidly destroying the cell wall by rapidly reducing the pressure in the decompression tank containing the sludge. Only, no special heat source or substance is used, so that the sludge solubilization treatment can be performed simply, safely and energy-saving.

In this case, the pressure reducing means is provided with a preliminary pressure reducing tank having a capacity larger than that of the pressure reducing tank, a vacuum pump for reducing the pressure in the preliminary pressure reducing tank, and a valve for opening and closing the pressure reducing tank and the preliminary pressure reducing tank. By opening a valve between the preliminarily depressurized tank and the depressurized tank, the pressure in the depressurized tank can be rapidly reduced.

Thus, the pressure in the decompression tank can be rapidly reduced by a simple device, and the cell membrane of microorganisms can be more reliably destroyed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sludge treatment apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the sludge treatment apparatus of the present invention. In the figure, reference numeral 1 denotes a sludge storage tank, and this sludge storage tank 1 is connected to a decompression tank 2 via a pipe 5 having a sludge pump 10 and valves 21 and 23. The sludge storage tank 1 is capable of supplying sludge to the decompression tank 2 via a sludge pump 10 and a pipe 5, and the decompression tank 2 is connected to the preliminary decompression tank 3 via a pipe 7 having a valve 24. ing.

A pipe 6 is connected between the valve 21 and the valve 23 of the pipe 5 to communicate with a biological reaction tank (not shown) for performing biological treatment. This pipe 6 is connected to a valve 22
And a pump 11. The sludge storage tank 1, the decompression tank 2, and the preliminary decompression tank 3 are connected in series via pipes 5, 7, respectively.

On the other hand, a deodorizing device 4 is connected to the preliminary pressure reducing tank 3 via a pipe 8. The pipe 8 is provided with a vacuum pump 12 for depressurizing the preliminary pressure reducing tank 3 and a valve 25 for opening and closing the pipe 8 between the vacuum pump 12 and the preliminary pressure reducing tank 3.

Next, the operation of the sludge treatment apparatus will be described. First, the valve 25 of the preliminary pressure reducing tank 3 is opened, and the valve 2 is opened.
By closing 4 and activating the vacuum pump 12,
The inside of the preliminary pressure reducing tank 3 is reduced to a predetermined vacuum pressure. In this case, the exhaust gas from the vacuum pump 12 is deodorized by the deodorizing device 4 connected to the pipe 8, and then discharged to the atmosphere.

After the pressure in the preliminary decompression tank 3 has decreased to a set value, the valves 21 and 23 are opened to drive the pump 10 so that the sludge in the sludge storage tank 1 is sent to the decompression tank 2 via the pipe 5. To At this time, the valve 22 of the pipe 6 leading to the biological reaction tank is closed. After the predetermined amount of sludge is fed into the decompression tank 2 in this manner, the pump 10
Is stopped, the valves 21 and 23 are closed, and the valve 24 between the preliminary pressure reducing tank 3 and the pressure reducing tank 2 is opened in a short time. As a result, the pressure in the pressure reducing tank 2 is rapidly reduced by the reduced pressure of the preliminary pressure reducing tank 3.

As a result, the sludge supplied into the decompression tank 2 is also affected by the decompression, and the intracellular bubbles of the microorganisms in the sludge are expanded by the negative pressure, and the cell wall is destroyed. As described above, the sludge in which the cell wall of the microorganism has been destroyed is returned from the decompression tank 2 to the biological reaction tank by driving the pump 11 with the valves 21 and 24 closed and the valves 22 and 23 opened.

The sludge returned to the reaction tank has the cell walls of the microorganisms destroyed, so that organic matter in the cells is decomposed by other microorganisms. By repeating the above procedure, the sludge supplied to the sludge storage tank 1 is subjected to the solubilization treatment in which the cell walls of the microorganisms are destroyed in a batch system.

[0018]

According to the sludge treatment apparatus of the present invention, it is possible to enlarge microbubbles in the cell wall of microorganisms and to destroy the cell wall by rapidly reducing the pressure in the vacuum tank in which the sludge is sealed. Since the pressure is merely reduced and no special heat source or substance is used, the solubilization treatment of the sludge can be performed simply, safely and energy-saving.

Further, the pressure reducing means includes a preliminary pressure reducing tank having a larger capacity than the pressure reducing tank, a vacuum pump for reducing the pressure in the preliminary pressure reducing tank, and a valve for connecting the pressure reducing tank and the preliminary pressure reducing tank to be openable and closable. By opening the valve between the decompressed preliminary decompression tank and the decompression tank and opening the valve, the pressure in the decompression tank is rapidly reduced, so that the pressure inside the decompression tank can be rapidly reduced by a simple device, and the cell membrane of microorganisms is destroyed. Can be performed more reliably.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one embodiment of a sludge treatment apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sludge storage tank 2 Decompression tank 3 Preliminary decompression tank 4 Deodorizing device 5-8 Piping 10, 11 Pump 12 Vacuum pump 21-25 Valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideaki Hamada 3-1-1, Shimosakabe, Amagasaki-shi, Hyogo Inside Hitachi Kiden Kogyo Co., Ltd. (72) Inventor Takuya Ando 3-1-1, Shimosakabe, Amagasaki-shi, Hyogo No. Hitachi Kiden Kogyo Co., Ltd. (72) Inventor Kosuke Oide 3-1-1, Shimosakabe, Amagasaki City, Hyogo Prefecture F-Term in Hitachi Kiden Kogyo Co., Ltd. 4D059 AA05 BK12 CA16 CA28 CB30

Claims (2)

[Claims] An apparatus for treating sludge, comprising: a decompression tank for sealing and sealing a sludge; and a decompression means for decompressing the inside of the decompression tank and destroying a cell membrane of microorganisms in the sludge. . 2. A pressure reducing means comprising: a preliminary pressure reducing tank having a larger capacity than the pressure reducing tank; a vacuum pump for reducing the pressure in the preliminary pressure reducing tank;
It is provided with a valve that opens and closes the decompression tank and the preliminary decompression tank, and opens the valve to communicate the depressurized predecompression tank and the decompression tank, thereby rapidly reducing the pressure of the decompression tank. The sludge treatment apparatus according to claim 1.