JPS5843296A - Treatment of night soil and sludge from purifying tank - Google Patents

Abstract

PURPOSE:To improve the efficiency of a denitrifying treatment for night soil by separating the sludge of a purifying tank to concd. liquid and separated liquid with a centrifugal concentrator, and feeding the concd. liquid to the denitrifying stage of night soil processes and the separated liquid to the aeration stage of the night soil processes. CONSTITUTION:The sludge from a purifying tank is introduced into a centrifugal concentrator 5, by which solids are concentrated. The concd. liquid is fed into a denitrifying tank 2 and the separated liquid into an aerating tank 3. In the tank 2, the liquid subjected to BOD removal and nitrification in a nitrifying tank 1 is denitrified under anaerobic conditions. When the concd. liquid of the sludge from the purifying tank is added thereto from the concentrator 5, the dissolved oxygen in the liquid fed from the tank 1 is quickly consumed. The separated liquid separated in the separator 5 is fed to the tank 3, where said liquid is subjected together with the denitrified liquid from the tank 2 to an aeration treatment for the purpose of removing residual BOD components.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for simultaneously treating septic tank sludge and human waste.

When septic tank sludge is treated in a human waste treatment facility, the two are mixed from the beginning, or the septic tank sludge is generally flowed into a sludge treatment system. However, such a treatment method cannot be said to efficiently treat both septic tank sludge and urine.

An object of the present invention is to provide a treatment method in which mixed septic tank sludge does not impede the treatment of human waste, and can even improve the efficiency of denitrification treatment of human waste.

Next, an example of the steps of the method of this invention will be explained with reference to all the drawings. In the process shown in FIG.
After passing through the denitrification tank 4112 and the aeration tank 6, it is sent to the settling tank 4, where the activated sludge is separated by precipitation, and the supernatant liquid is discharged as treated water. Ru. Further, a part of the settled sludge is returned to the nitrification tank 1 as return sludge, and the remainder is discharged as surplus sludge. Since this process is common as a normal human waste treatment process, a detailed explanation thereof will be omitted.

On the other hand, in the method of this invention, the septic tank sludge to be treated together with human waste is first introduced into the centrifugal concentrator 5, where the solid matter is concentrated. The concentrated liquid is then sent to the denitrification tank 2, and the separated liquid is sent to the aeration tank 6.

In the denitrification tank 2, the denitrification process for the liquid that has been subjected to BOD removal and nitrification in the nitrification tank 1 is performed under anaerobic conditions. When the nitrification tank 1 is added, the dissolved oxygen in the liquid sent from the nitrification tank 1 is quickly consumed. This concentrated liquid also serves as a necessary carbon source for the denitrification reaction to proceed. For these two reasons, the speed of the denitrification reaction taking place in the denitrification tank 2 increases considerably. Further, the separated liquid separated by the centrifugal concentrator 5 is sent to an aeration tank 6, and together with the denitrification liquid from the denitrification tank 2, is subjected to aeration treatment to remove residual BOD.

Before supplying to the nitrification tank 1, the human waste is digested in the 1° nitrification tank under anaerobic conditions, and the digested and desorbed liquid is
,・ may be supplied as it is, and some 7 may be supplied to the unfit tank 1 by force.

Although the centrifugal concentrator 5 may be of a becanter type, an example of a preferred specific structure is shown in FIG.

A basket 16 supported by a vertical rotation shaft 12 is accommodated in the housing indicated by the reference numeral 11 in FIG.
A filter cloth 14 is arranged along the inner surface of this basket 16. The basket 16 and the filter cloth 14 are rotated at high speed by power supplied from the outside to the rotating shaft 12 via the pulley 15.

The liquid to be treated is then passed through the supply pipe 16 to the filter cloth 1.
It is fed to the center of 4. Since the rotating basket 16 and the filter cloth 14 have an upside-down trapezoidal shape and are rotating at high speed, the liquid in the wastewater passes through the small holes of the filter cloth 14 and the basket 16 due to the action of centrifugal force. The solids are released into the filtrate chamber 17 in the radial direction, and the solids move on the filter cloth 14 in the direction away from the center of rotation (upward in FIG. 2) due to the action of centrifugal force, and are then discharged from the filtrate chamber 17 through the partition wall 18. The concentrated liquid is discharged into the separated concentrate chamber 19. As a result, the separation of 88 in the waste water is carried out efficiently, and the concentrate and filtrate containing a large amount of SS are taken out separately through pipes 20 and 21, respectively.

The reference numeral 22 indicates a cleaning pipe provided with a large number of nozzles 26, which is used to interrupt the operation and perform cleaning when the filter cloth 14 or the like becomes clogged.

3 and 4 respectively show other steps of the method of the invention. First, in the process shown in FIG. 3, human waste is directly introduced into the denitrification tank 21, where the nitric acid in the circulating fluid and the BOD source contained in the inflowing human waste and the concentrated liquid from the centrifugal concentrator 5 are utilized. denitrification treatment is carried out efficiently. Further, the separated liquid from the centrifugal concentrator 5 is sent to the nitrification tank 22 together with the denitrification treatment liquid, where BOD is removed and nitrification is performed. A part of the nitrification liquid is returned to the denitrification tank 21 as a circulating liquid, and the remainder is sent to the sedimentation tank 4.

Further, in the example shown in FIG. 4, the human waste is subjected to nitrification and denitrification treatment while being aerated in the denitrification tank 61.

This denitrification tank 61 also receives a concentrated solution of purified sludge sent from the centrifugal concentrator 5, so that the MLSS inside is at a high level, and even with aeration, dissolved oxygen is 0.5
It is kept below yy/A'. Centrifugal thickener 62 for vaporized liquid
The concentrated liquid is returned to the aeration tank 61, and the separated liquid is sent to the attached aeration tank 66 together with the separated liquid from the centrifugal concentration ia5. This sticky air jft
Inside I53, aeration is carried out using a biological filter bed in which microorganisms are attached to a suitable filter medium, and a part of the aeration liquid is returned to the denitrification tank 61 as a circulating liquid, and the remainder is sent to the settling tank 4. It will be done. In addition, a part of the settled sludge separated in settling tank 4 is
The sludge is sent to the centrifugal concentrator 5, concentrated together with the septic tank sludge, and then returned to the dust tank 61.

In the examples shown in FIGS. 3 and 4, as in the case of FIG. 1, all of the desorbed liquid obtained by enriching human waste and subjecting it to anaerobic digestion may be treated.

As described above, according to the method of the present invention, septic tank sludge is first concentrated by a centrifugal concentrator, and the concentrated liquid is supplied to the denitrification process of the human waste treatment process, and the separated liquid is supplied to the aeration process. The concentrated liquid supplied to the decapping process works to increase the sludge concentration of the liquid in the denitrification tank, thereby increasing the efficiency of the denitrification process, and on the contrary increases the treatment effect of the human waste treatment process as a whole. This is an advantage.

[Brief explanation of drawings]

FIG. 1 is a 70-sheet showing an example of the process of the method of the present invention, FIG. 2 is a schematic vertical sectional view showing an example of the structure of a centrifugal concentrator used in the process of FIG. Figure 4 is a flow sheet showing other steps. 1... Nitrification tank, 2... Denitrification tank, 6... Aeration tank,
4...Centrifugal cypress, 5...Centrifugal concentrator, 11...Housing, 12...times km, 16...Basket,
14... (Face, 16... Supply vibe, 17...
Filtration IK chamber, 18... Partition wall, 19... Concentrate liquid chamber, 21
... denitrification tank, 22 ... nitrification tank, 61 ... denitrification tank,
62... Centrifugal concentrator, 66... Adhesive aeration tank.

Claims (2)

[Claims] (1) Separate the septic tank sludge into a concentrated liquid and a separated liquid by concentrating it with a centrifugal concentrator, the concentrated liquid is sent to the denitrification process of the human waste treatment process, and the separated liquid is sent to the aeration process of the human waste treatment process. A method for treating human waste and septic tank sludge, the method comprising sending human waste and septic tank sludge to a septic tank. (2) The aeration process of the above-mentioned human waste treatment process is carried out in a deposited aeration tank, and a treatment solution obtained by solid-liquid separation of the denitrification solution is supplied to the deposited aeration tank. Range 1
Method for treating human waste and septic tank sludge as described in Section 1.