JPS60238200A - Treatment of sludge - Google Patents

Abstract

PURPOSE:To efficiently treat high concn. sludge by fine air bubbles, by mixing compressed air into a sludge supply pipe and directly breaking said air by an ultrasonic wave to adhere the same to the solid component in treated sludge. CONSTITUTION:Sludge 5 to be treated is guided to a nozzle 6 from a sludge tank 2 and compressed air is guided to and mixed in the downstream side of said nozzle 6. At the same time, said air formed into extremely fine air bubbles by ultrasonic waves from an oscillator 7 while said fine air bubbles are uniformly dispersed throughout the sludge 5 to be treated to be sufficiently adhered to the solid component in the sludge 5. By this method, high concn. sludge can be treated with good efficiency without requiring large amount recirculation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sludge treatment method suitable for particularly high concentration sludge treatment in water treatment and the like.

Conventionally, as a method for treating this kind of sludge, a method is known in which fine air bubbles are supplied into the sludge to adhere to the solid content in the sludge, and the bubbles are floated above the sludge and removed. The microbubbles are supplied into the sludge by circulating the separated water in the sludge thickening tank through a pressurized tank and supplying compressed air into the pressurized tank. The compressed air is dissolved in circulating water, and when the pressurized circulating water is returned to the sludge thickening tank, the pressure is reduced and the dissolved compressed air is supplied as fine bubbles, making it difficult to treat highly concentrated sludge. This method has the disadvantage that the amount of compressed air dissolved in the clear water must be increased by increasing the pressure in the pressurized tank or by increasing the amount of separated water circulated.

It is an object of the present invention to provide a sludge treatment method capable of efficiently treating highly concentrated sludge without using a high-pressure pressurized tank or circulating a large amount of separated water. The sludge to be treated is continuously supplied from the sludge tank to the sludge thickening tank via the sludge supply pipe, and compressed air is mixed into the supply pipe, which is immediately destroyed by ultrasonic waves and generated into fine bubbles. The solid content in the sludge to be treated is deposited in the supply pipe, and then introduced into a vaginal thickening tank for flotation separation.

Embodiments of the present invention will be described above with reference to the accompanying drawings.

FIG. 1 shows an example of a sludge treatment facility for carrying out the sludge treatment method of the present invention. In the figure, 1 indicates a sludge thickening tank;
Sludge 5 to be treated was continuously supplied from a sludge tank 2 through a sludge supply pipe 4 equipped with a supply pump 3.

Further, a nozzle 6 is interposed on the downstream side of the pump 3 of the sludge supply pipe 4 to maintain a negative pressure in the vicinity of the downstream thereof, and a vibrator 8 connected to an oscillator 7 is provided in the negative pressure region of the sludge supply pipe 4. Compressed air was supplied from a near compressor 10 via a compressed air supply pipe 9. In the figure, 11 indicates a concentrated sludge outlet, and 12 indicates a separated water outlet.

Here, an example of the sludge treatment method using the treatment device is shown. First, the sludge to be treated 5 is introduced from the sludge tank 2 to the nozzle 6, and the compressed sludge is supplied from the compressor 10 using the negative pressure generated downstream of the nozzle 6. The air is guided to the downstream side of the nozzle 6, where compressed air is mixed into the sludge to be treated 5, and at the same time an ultrasonic wave of a desired frequency is generated by the vibrator 8 according to the setting signal of the compressed air oscillator 7. For example, 40~
They are broken into extremely fine bubbles of 80 μm, dispersed uniformly in the sludge 5 to be treated, and sufficiently adhered to the solid content in the sludge 5 to be treated, and then the sludge 5 to be treated is exposed to the atmosphere. The sludge is guided to the sludge thickening tank 1 and the solids with fine bubbles attached thereto are floated above the sludge thickening tank 1. This is done continuously, and the solid concentrated sludge collected above the thickening tank 1 is sequentially discharged from the discharge port 11, and the separated water is sequentially discharged from the separated water discharge port 12.

As described above, according to the present invention, compressed air is mixed into the sludge supply pipe, and the air is immediately destroyed by ultrasonic waves to generate fine bubbles, which are then attached to the solids in the sludge to be treated in the supply pipe. As a result, extremely fine air bubbles can be adhered to the solid content without using a high-pressure tank or circulating a large amount of separated water, making it possible to efficiently treat highly concentrated sludge and using ultrasonic vibrations. By simply controlling the number of microbubbles, it is possible to supply microbubbles with a particle size that matches the sludge concentration of the object to be treated, which has the effect of allowing optimal sludge treatment depending on the object to be treated.

[Brief explanation of drawings]

FIG. 1 is a system diagram of an embodiment of a sludge treatment facility for carrying out the sludge treatment method of the present invention, and FIG. 2 is a cutaway sectional view of its hard surface. 1... Sludge thickening tank 2... Sludge tank 4... Sludge supply pipe 5... Sludge to be treated 7... Oscillator 8... Vibrator 10... 2 people outside the near compressor Figure 1 Figure 2

Claims (1)

[Claims] The sludge to be treated is continuously supplied from the sludge tank to the sludge thickening tank via a sludge supply pipe, and compressed air is mixed into the supply pipe, which is immediately destroyed by ultrasonic waves to generate fine bubbles, and then the sludge is supplied. attached to the solid content in the sludge to be treated in the pipe,
A sludge treatment method that consists of leading the sludge to a thickening tank and flotation separation.