JPH03123696A - Treatment of sewage - Google Patents

Abstract

PURPOSE:To reduce the size and capacity of a sewage treatment apparatus and to relax the restriction of the arrangement position of a purifying tank by arranging a vacuum generator to the front stage of the sewage treatment apparatus and setting the stagnation time of sewage in the vacuum generator to a specific time. CONSTITUTION:A tank 14 equipped with an ejector type vacuum generator 12 is provided to the front stage of a sewage treatment apparatus 10 and sewage 16 is circulated within the tank 14 by the ejector 22 provided in the tank 14 and, at this time, vacuum is generated. The volume of the tank 14 is set so as to stagnate the sewage for 6-19hr. The sewage 16 in a sewage pit 30 is sucked to the tank 14 of the vacuum generator 12 along with air under vacuum. By injecting the sewage 16 and air, the dissolving action of air in the sewage 16 is effectively performed and the sewage receives the decomposing action of bacteria for a long time and, therefore, the sewage is pretreated and pre- purified during the stagnation in the tank 14.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a sewage treatment method, and more particularly to a sewage treatment method performed using a vacuum generator.

(Prior art and problems to be solved by the invention) As a wastewater treatment method, wastewater is sucked and collected by a vacuum generated by a vacuum generator and sent to the subsequent wastewater treatment flLat, where the wastewater is purified. Vacuum wastewater treatment methods are known.

Conventionally, the vacuum generator for this vacuum-type sewage treatment method includes one in which a vacuum pump is used to generate a vacuum, and another in which an ejector is used to generate a vacuum.

The latter type of ejector type temporarily stores wastewater in a tank and uses an ejector to eject and circulate it to generate a vacuum, but conventional vacuum generators are only used to generate a vacuum. However, there is no particular ability to purify sewage within the tank, and therefore, a subsequent sewage treatment device with high purification ability and large capacity was required.

On the other hand, in a septic tank that is used as a sewage treatment device installed in each home, vacuum suction is not performed by such a vacuum generator, and the sewage is normally purified by flowing into the tank by gravity. Therefore, there is a problem in that the installation position is subject to certain restrictions so that the wastewater can flow smoothly into the tank.

(Means for Solving the Problems) The present invention has been made to solve these problems, and its gist is to create a vacuum by ejecting and circulating sewage in a tank using a jetter. The generator is disposed upstream of the sewage treatment equipment, and the residence time of the sewage in the vacuum generator is set to 6 to 19 hours.

(Operation and Effects of the Invention) Conventionally, in ejector-type vacuum generators, the amount of sewage stored in the tank is small, and the amount usually depends on the retention time from when the sewage flows into the tank until it flows out of the tank. 0.6-2
．． It's only about 2 hours.

- In the old invention, the capacity of the tank of this vacuum generator is increased to increase the retention time of sewage from 6 to 19 hours, and by doing this, the ability to purify sewage is imparted to the vacuum generator. can do. In an ejector-type vacuum generator, since air is vigorously ejected into the wastewater stored in the tank together with the wastewater, a large amount of air is dissolved into the wastewater. When a large amount of air is dissolved in wastewater in this way, the activity of the bacteria contained in the wastewater increases, which causes the filth in the wastewater to be decomposed and purification to take place. That is, prior to the purification treatment by the original sewage treatment device, pre-aeration treatment and pre-purification treatment of the sewage water is performed in this vacuum generator.

By the way, in a sewage treatment apparatus, a flow rate adjustment tank is provided in order to alleviate fluctuations in the flow rate of sewage, but according to the present invention, such a flow rate adjustment tank can be omitted. This is because, according to the present invention, wastewater is allowed to remain in the tank of the vacuum generator for a long time, so that the flow rate can be adjusted there. The flow rate adjustment tank is equipped with a screen for removing impurities, a blower for aeration to prevent sedimentation, a blower for stirring, etc., but in the present invention, the ejector crushes the impurities with injection energy, and Since aeration and agitation are performed at the same time, there will be no problem even if the flow rate adjustment tank is omitted.In addition, the ejector's atomization effect on coarse solids will reduce the amount of solids in the subsequent sewage treatment equipment. is easily decomposed by microorganisms.

Further, since the wastewater is pre-treated in the vacuum generator, even if food processing wastewater is introduced into the wastewater, the wastewater can be sufficiently treated by the wastewater treatment equipment in the subsequent stage.

As described above, according to the present invention, the pretreatment of wastewater, that is, the prepurification action is performed in the vacuum generator.

Accordingly, the processing capacity of the original sewage treatment device at the subsequent stage is supplemented, and the flow rate adjustment tank can be omitted, resulting in the effect that the sewage treatment device can be made smaller and smaller in capacity.

Further, when the present invention is applied to Class B, wastewater can be collected by vacuum suction power, so there is an advantage that restrictions on the installation position of the septic tank are relaxed.

(Example) Next, embodiments of the present invention will be described in detail based on the drawings.

In FIG. 1, IO is a sewage treatment device, and an ejector-type vacuum generator 12 is provided at the front stage thereof. This vacuum generator 1112 has a tank 14 in which waste water 16 is stored. The stored wastewater 16 is sent to the wastewater treatment system filo by a pump 18 through a pipe 2o.

An ejector 22 is provided inside the tank 14, and the ejector 22 circulates the waste water 16 within the tank 14, and at the same time generates a vacuum. That is, the wastewater 16 in the tank 14 is guided into the circulation path 26 by the pump 24 (here, a submersible pump, but it does not have to be an ice pump), and is further vigorously introduced into #f114 from the spout 28 of the ejector 22. and generates a vacuum based on the jet stream.

The capacity of the tank 14 of the vacuum generator 12 is set so that the wastewater 16 that has flowed into the tank 14 remains there for 6 to 19 hours before flowing out of the tank 14.

The vacuum generated by the vacuum generator 12 is transmitted to the wastewater bit 30 through the main pipe 32 and the branch pipe 34, and the wastewater 16 in the wastewater bit 30 passes through the branch pipe 34 and the main pipe 32 to generate a vacuum together with air. Attire! ! 12 tanks 14
is vacuum-suctioned.

Incidentally, sewage 16 from a washbasin 36, toilet bowl, etc. flows into the sewage bit 30 through a pipe 38, and is stored therein in a fixed amount.

Further, the vacuum toilet bowl 40 may be directly connected to the main pipe 32 via the branch pipe 42 without using the sewage bit 30 as described above.

An air introduction pipe 44 is connected to the main pipe line 32,
Air is introduced into the main pipe 32 under the control of a solenoid valve 46 that is activated by detecting the pressure within the main pipe 32 .

In general, in a vacuum sewage treatment system, sewage generation concentrates at a predetermined time of the day. Conventionally, vacuum generators operate in a closed state when sewage is generated and supplied, and stop operating when the generated sewage runs out. Specifically,
When the flow of sewage into the sewage bit 30 is stopped and the amount of sewage stored in the sewage bit 30 decreases below a certain level, the operation is stopped based on the decrease in pressure within the main pipe 32 (sewage piping). When the water level of the sewage drops, the valve 31 closes to cut off communication between the sewage bit 30 and the vacuum piping),
Therefore, in the present invention, when the pressure within the main pipe 32 drops below a certain level, air is introduced into the main pipe 32 to prevent the pressure from decreasing, thereby allowing the ejector 22 to continue operating.

This reduces the intermittent operation stop time of the ejector 22 from 15 to 20 hours in the conventional vacuum generator to 0 to 8 hours, thereby sufficiently circulating the waste water 16 in the tank 14 of the vacuum generator 12 and preventing air dissolution. This is to promote this.

The feature of the method of this example is that a one-type ejector type vacuum generator 12 is provided at the front stage of the sewage treatment equipment IO, that is, on the upstream side, and the capacity of the tank 14 of the vacuum generator 12 is increased so that the sewage inside This is because the residence time of No. 16 was set as long as 6 to 19 hours.

In the ejector-type vacuum generator 12 described above, the ejector 22 ejects the waste water 16 and air, causing the waste water to 16
Since the dissolution of air into the wastewater 16 is effectively carried out, and the wastewater 16 remains in the vacuum generator 12 for a long time, the activity of the bacteria present in the wastewater 16 itself increases. Since the wastewater 16 is subjected to the decomposition action of bacteria for a long time, pretreatment and prepurification are performed while the wastewater 16 remains in the tank 14.
The wastewater 16 that has undergone such pre-purification treatment is sent to the original wastewater treatment device 10.

In addition, the tank 14 of the vacuum generator 12 has a large capacity, and the waste water 1
Since the residence time of 6 is long, it also has the function as a flow rate adjustment tank in conventional sewage treatment equipment, so it is possible to omit the flow rate adjustment tank in the sewage treatment equipment 10, making the sewage treatment equipment 10 smaller. What you do is called maizō.

Incidentally, the system in this example performs wastewater purification treatment,
When the quality of the waste water 16 in the vacuum generator 112 was investigated, the results shown in Table 1 were obtained.

(Left below) As shown in the results, according to the present invention, there are fewer foreign substances in the tank 14 of the vacuum generator 12, and B
It can be seen that the OD and COD have also decreased, and that the filth has been decomposed and the sewage 16 is becoming more explosive.

Although the embodiments of the present invention have been described above in detail, the present invention can also be implemented in other embodiments.

For example, in the present invention, sewage from a toilet bowl or the like may be caused to flow into the tank of the vacuum generator by gravity, or
In addition, the present invention can be applied to any organic wastewater, such as wastewater including food processing wastewater, etc., as a person skilled in the art, without departing from the spirit of the invention. It can be implemented with various modifications based on knowledge.

[Brief explanation of drawings]

Figure yS1 is a diagram systematically showing a vacuum sewage treatment system that is an embodiment of the present invention. lO: Sewage treatment device 12: Vacuum generator 14: Tank 16: Sewage 22: Ejector

Claims (1)

[Claims] A vacuum generator that generates a vacuum by ejecting and circulating the sewage in the tank using an ejector is installed in the front stage of the sewage treatment equipment, and the residence time of the sewage in the vacuum generator is set to 6 to 19 hours. A sewage treatment method characterized by: