JPH029845B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the recovery of human waste contained in human waste or human waste septic tank sludge (hereinafter simply referred to as human waste),
The present invention relates to a device for concentrating surplus activated sludge, coagulation-sedimentation sludge, etc. generated during biological treatment or coagulation-sedimentation treatment of sludge-removed human urine.

[Conventional technology]

The conventional human waste disposal method is as shown in Figure 1.
In order to process raw human waste 1 by an activated sludge method or the like, or to reduce the amount of surplus activated sludge 13 generated, coarse fibers are removed before processing in biological treatment step 4. is separated separately on screen 2, and the separated coarse fibers are collected and called residue 17. This collected residue 17 contains a large amount of raw human urine 1, which poses a problem in terms of hygiene and odor when handling or using the collected residue 17.

On the other hand, the filtered human waste (liquid from the screen 2) 3 is treated in a biological treatment step 4 to become primary treated water 5, which is separated into secondary treated water 7 and return sludge 12 in a settling tank 6. The secondary treated water 7 is further flocculated with a flocculant 9 added in the coagulation-sedimentation treatment step 8 for the purpose of removing chromaticity, COD components, etc., if necessary, and coagulated with the tertiary treated water 10. Sedimented sludge 1
It is separated into 1.

Most of the returned sludge 12 is returned to the biological treatment process 4, but a part of it is withdrawn as surplus activated sludge 13, and is sedimented and concentrated together with the coagulated and precipitated sludge 11 in the thickening tank 14, and is converted into supernatant water 16 and thickened sludge 18. The separated supernatant water 16 is sent again to the biological treatment process 4.
The surplus activated sludge 13 flowing into the thickening tank 14 is composed of fine organic solids mainly composed of bacterial cells, including cell water inside the bacterial cells and viscous substances outside the bacterial cells (usually called polysaccharides). Concentration is poor because it contains a large amount of water that is difficult to liberate.
In addition, the coagulated sedimentation sludge 11 has a low solid concentration, and the coagulant 9 was injected to remove color and COD components.
(Aluminum sulfate, iron chloride, etc.) are contained as hydroxides, so the concentration property is also poor, and the concentration of solids in the obtained thickened sludge 18 is low. Flocculant 2
2 (slaked lime, inorganic flocculants such as ferric chloride or organic polymer flocculants, etc.) increases,
Moreover, since the amount of water separated during dehydration increases, a large dehydrator 19 is required. For this reason, a flocculant 15 (usually a cationic polymer flocculant) is added to the concentration tank 14 for concentration.
Because the sludge retention time in step 4 is long (in the case of sewage sludge concentration, it is determined to be about 12 hours according to the sewerage facility design guidelines), the injected flocculant 15 decomposes.
It was not possible to obtain thickened sludge 18 having a high solid content even though it was injected.

Note that 20 is separated water from the dehydrator 19 and is sent to the biological treatment process 4, and 21 is a dehydrated cake.

In addition, as a modification of the method shown in FIG. 1, there is also a method in which a flocculant 15 is added to the flocculant-sediment sludge 11 or surplus activated sludge 13 to flocculate it, and then the mixture is supplied to the screen 2 together with the human urine 1 to be concentrated. However, since the obtained concentrated sludge contains human waste, the human waste removal rate is poor, and moreover, flocculated sludge often flows out from the screen 2, resulting in a lower recovery rate.

[Problem to be solved by the invention]

An object of the present invention is to provide a rational and economical apparatus that can effectively eliminate the above-mentioned conventional drawbacks and obtain sludge and concentrated sludge with a low rate of human waste adhesion.

[Means to solve the problem]

The present invention has a horizontal rotating cylindrical screen with a double structure, and has a human waste supply port opened at one end of the outer screen, a collection and waste discharge port opened at the other end, and a human waste disposal port at one end of the inner screen. A device for concentrating human waste and sludge in human waste treatment, characterized in that a supply port for sludge generated in a process is opened and a concentrated sludge discharge port is opened at the other end.

[Effect]

The operation of the present invention will be explained with reference to FIG.
The human waste 1 is first collected by the external cylinder screen 29 of the rotating screen, and then becomes the removed human waste 3, which is processed in the biological treatment process 4 to become the primary treated water 5, and then processed into the secondary treatment water in the sedimentation concentration tank 6. Treated water 7 and returned sludge 1
It is separated into two parts. If necessary, a flocculant 9 is added to the secondary treated water 7 in a coagulation-sedimentation process 8 for flocculation treatment, and the water is separated into tertiary-treated water 10 and flocculation-sedimentation sludge 11.

Most of the returned sludge 12 is returned to the biological treatment process 4, but the surplus is extracted as surplus activated sludge 13 and sent to the flocculation tank 24 together with the coagulated and settled sludge 11.
After being flocculated with the flocculant 15 added in step 1, the flocculated sludge 25 is fed into the inner cylinder screen 30 of the rotating screen, and separated water 27 and thickened sludge 18 are
The separated water 27 is led to the biological treatment process 4 together with the filtered human urine 3. As the flocculant 15 added to the flocculating tank 24, a cationic polymer flocculant is usually used, but an anionic polymer flocculant may be used depending on the content of the coagulated and settled sludge 11.

The collected sludge 17 collected and concentrated by the outer cylinder screen 29 and the concentrated sludge 18 separated by the inner cylinder screen 30 are supplied to the dehydrator 19, where a flocculant 22 is injected as necessary to dehydrate and separate them. It is separated into water 20 and dehydrated cake 21, and the separated water 20 is returned to the biological treatment process 4 for treatment.

In addition, in the above process, the outer cylinder screen 29
The pore diameter is set to 0.5 mmφ in order to increase the recovery rate when the collected residue 17 is to be effectively used as a dewatering aid for the thickened sludge 18 in the dehydrator 19.
When using a fine screen to collect and remove residue as mere contaminants, use a 2mmφ screen.
Use a coarse screen. On the other hand, the pore diameter of the inner cylinder screen 30 varies depending on the type of flocculant 15 added and the injection rate, and the larger the pore diameter, the higher the concentration of solids in the obtained thickened sludge 18. Coagulated sludge 25
Usually 0.1 to 0.5 mm, as the recovery rate decreases due to leakage.
It is preferable to use a screen with a hole diameter of φ.

Furthermore, the flocculated sludge 2 is
Separated water 27 when concentrating 5 is collected in the outer cylinder screen 29 and is collected by dripping onto the residue.The raw urine and fine particles contained in the residue are washed and removed, resulting in sanitary recovery with less bad odor. A residue 17 can be obtained.

〔Example〕

One embodiment of the present invention will be described with reference to FIGS. 3 and 4. An inner screen 30 is disposed within a horizontal outer screen 29 rotatably disposed by a support roll 28. Support rod 31
The outer cylinder screen 29 and the inner cylinder screen 30 are fixed concentrically with each other, and a weir plate 32 is attached around the entire circumference to one end opening of the outer cylinder screen 29 and the inner cylinder screen 30. A raw human waste supply pipe 33 is opened in the screen 29, and a flocculated sludge supply pipe 34 is opened in the inner cylinder screen 30 from the attachment opening of the inner cylinder screen 30 and the weir plate 32, and the collected sludge is collected at the other end.
It has a structure in which a thickened sludge discharge port 36 is provided.

In addition, 37 is a support roll drive device, and 38 is a separated water receiver.

Thus, the human waste 1 supplied from the human waste supply pipe 33 into the outer cylinder screen 29 is collected by the external cylinder screen 29 and separated into waste 17 and removed human urine 3, and the removed human urine 3 is separated into separated human waste. It is stored in the receiver 37. The flocculated sludge 25 supplied into the inner tube screen 30 from the flocculated sludge supply pipe 34 is separated into thickened sludge 18 and separated water 27 by the inner tube screen 30, and this separated water 27 is also transferred to the separated water receiver 37.
The collected waste is stored in the sludge and sent to the biological treatment process 4 in FIG. 2 together with the removed human waste 3 for processing.

On the other hand, collected sludge 17 and thickened sludge 1 remain in the outer cylinder screen 29 and inner cylinder screen 30, which are rotated by the support rolls 28, respectively.
8 etc. are given a slow rolling motion within these screens, and this rolling motion collects raw urine and concentrated sludge 18 contained in the residue 17.
Separated water, etc. contained in the water oozes out and is further separated, condensing it and collecting it.
5 and the thickened sludge discharge port 36, respectively, and sent to the dehydrator 19 shown in FIG.

In such a horizontal rotating cylindrical screen, since the outer cylinder screen 29 and the inner cylinder screen 30 are independent, the sludge 17 and flocculated sludge 25 are separated from each other.
It is possible to adopt a screen with a hole diameter suitable for the outer cylinder screen 29 and the inner cylinder screen 3.
0 at the same rotation speed, even if the peripheral speed of the outer cylinder screen 29 is set to a value suitable for residue collection, the peripheral speed of the inner cylinder screen 30 will be lower than that of the outer cylinder screen 29.
By setting the diameter of the inner cylinder screen 30 to a certain value, a peripheral speed suitable for concentrating the flocculated sludge 25 can be set. That is, there is no particular need for two drive devices 36, one for driving the outer tube screen 29 and the other for driving the inner tube screen 30, and only one drive device is sufficient, which simplifies the structure.

Furthermore, the separated water 2 of the flocculated sludge 25 supplied from the flocculated sludge supply pipe 34 to the inner cylinder screen 30
7 serves as water for washing and removing raw urine contained in the collected residue 17 and particles smaller than the pore size of the outer cylinder screen 29 by dropping it dropwise onto the collected residue 17 in the outer cylinder screen 29. raw human urine 1
It is possible to collect, wash and classify the residue without using new washing water, by increasing the removal rate of particles and increasing the classification rate of particles smaller than the pore size of the outer cylinder screen 29.

In the examples shown in FIGS. 3 and 4, the outer cylindrical screen 29 is supported and rotated by the support roll 28, but a rotating shaft is provided in the inner cylindrical screen 30, and the inner cylindrical screen 30 is supported and rotated by a support rod. Installation, outer cylinder screen 29 and inner cylinder screen 3
0 may be supported and rotated. In addition, a spiral partition plate is attached to the entire circumference or part of the outer cylinder screen 29 and the inner cylinder screen 30, and the sludge 17 and concentrated sludge 18 are collected by rotation of these screens and forced along the partition plate. It may also be discharged.

〔Effect of the invention〕

As described above, according to the present invention, the collection of human waste and the concentration of sludge in human waste treatment are performed in the same device using separate screens.
Screen pore diameters suitable for both sludge collection and sludge concentration can be selected, increasing the recovery rate of thickened sludge and preventing the thickened sludge from coming into contact with human waste, making it possible to collect sludge in an extremely rational manner. The sludge is concentrated, and the sludge is automatically collected and washed with water separated from the thickened sludge, resulting in a high rate of human waste removal and a higher classification of unnecessary fine particles contained in the collected sludge. It is possible to stably obtain thickened sludge with a high solids concentration, and the structure of the device is simple and can be manufactured at low cost.It is easy to maintain and manage, and many other effects can be obtained.

[Brief explanation of drawings]

Fig. 1 is a system explanatory diagram showing a conventional method, Fig. 2 is a system explanatory diagram showing an embodiment of the present invention, Fig. 3 is a longitudinal cross-sectional side view showing an embodiment of the present invention, and Fig. 4 is a system explanatory diagram showing an embodiment of the present invention. FIG. 3 is a front view of FIG. 3; 1... Raw human waste, 2... Screen, 3... Removal human waste, 4... Biological treatment process, 5... Primary treated water,
6...Sedimentation concentration tank, 7...Secondary treated water, 8...Coagulation sedimentation treatment step, 9, 15, 22...Flocculant, 1
0...Tertiary treated water, 11...Coagulation and sedimentation sludge, 12
...Return sludge, 13... Surplus activated sludge, 14...
Concentrating tank, 16...supernatant water, 17...recovered residue, 1
8... Thickened sludge, 19... Dehydrator, 20, 27...
... Separated water, 21 ... Dehydrated cake, 24 ... Coagulation tank, 25 ... Coagulated sludge, 28 ... Support roll, 2
9... Outer tube screen, 30... Inner tube screen, 31... Support rod, 32... Weir plate, 33...
Raw human waste supply pipe, 34...Agglomerated sludge supply pipe, 35...Collected residue discharge port, 36...Thickened sludge discharge port, 37...Support roll drive device, 38...
Separated water receiver.

Claims (1)

[Claims] 1 The horizontal rotating cylindrical screen has a double structure, and one end of the outer cylindrical screen has a supply port for human waste, and the other end has a collection and waste discharge port, and one end of the inner cylindrical screen is designed to remove human waste generated during the human waste treatment process. 1. A device for concentrating human waste and sludge in human waste treatment, characterized in that a supply port for the sludge is opened and a concentrated sludge discharge port is opened at the other end.