JPS62121611A - Method for treating waste water - Google Patents

Abstract

PURPOSE:To save labor and time required for cleaning a screen, by returning treated water to a pretreating tank to spray said water from a spray nozzle on a screen, decomposing treatable substances on the screen, and sending said substances to a crusher. CONSTITUTION:Waste water flows in through an inlet port 11, where heavy substances sink in a sand settler 15, whereas suspended substances catch on a bar screen 13 and the rest is discharged through a crusher 2 and treating tanks 3. The treating tanks 3 consist of an adjusting tank 31, an aeration tank 32, a settling tank 33, and sterilizing tank 34. The settling tank 33 is equipped with an antifoaming pump 5 which is connected to a nozzle 12 in a pretreating tank 1 by a line 7. Treated water in the settling tank 33 is led by the pump 5 to the pretreating tank through the line 7, where said water is sprayed from the nozzle to hit the waste on the screen 13. Treatable substances of the wastes are decomposed and sent to the crusher 2.

Description

[Detailed description of the invention] A. Purpose of the invention (industrial application field) Waste water for treating domestic wastewater from each facility to a water quality standard necessary for environmental hygiene and discharging it into parking areas, service areas, interchanges, etc. There is processing equipment. The present invention is directed to a method for treating sewage in such facilities, particularly a method for treating sewage, etc. in a human waste septic tank.

(Prior Art) Sewage is discharged through a pretreatment tank 1, a crusher 2, and a treatment tank 3 as shown in FIG. A pretreatment tank 1 equipped with a sand settling basin and a bar screen receives wastewater from each facility.
This process removes impurities in the water and those that cannot be treated with current treatment facilities, such as solids, poorly water-soluble materials, vinyl, and sand. Unless there are special circumstances, sewage flows in by a drop type, and the most filth collects in this process.
It is easy to cause odor and pests. Floating objects in the water are stopped here by a bar screen, but most of them are paper waste,
Processable materials such as raw blocks. These may be removed singly, but the removed material is very difficult to treat and is generated in large quantities.
Also, at this stage, the weight as a load is large. Therefore, it is desirable to move the processable items to the next step and remove only the unprocessable items. However, pouring it into the crusher can cause the crusher to malfunction, so currently, it is physically broken down by beating with tap water, etc. before being sent to the next process.

(Problems to be Solved by the Invention) The above-mentioned work of tapping with tap water etc. is a simple work, but requires time and effort. Particularly during busy periods, there is a risk that the screen will become clogged, causing the water level to rise and overflow, so maintenance personnel must inspect the screen room from time to time as part of their necessary duties. Therefore, it is desirable to perform this process automatically and add human power as necessary.

Structure of the invention (Means for solving the problem) Sewage is treated in a treatment tank including an adjustment tank and an aeration tank, and this water is returned to a pre-treatment tank using a defoaming pump in the treatment tank. Water is sprayed onto the screen from the water nozzle. This decomposes the processable material on the screen and sends it to a crusher located between the pretreatment tank and the processing tank.

(Operation) The treated water is injected from the nozzle toward the screen through the pipe line by the defoaming pump pressure.

As a result, the processable material on the screen is knocked down, broken down, and sent to the crusher for the next step.

(Embodiment) In the drawings, the same numbers refer to the same or corresponding parts.

Sewage flows in from the inlet 11. The heavy objects therein sink into the sand settling basin 15, the floating objects are caught on the bar screen 13 and stopped, and the rest passes through the crusher 2 and the processing tank 3, and then the first
The water is discharged to the right in the figure. The treatment tank 3 includes an adjustment tank 31, an aeration tank 32, a settling tank 33, and a sterilization tank 34. Sedimentation tank 33
is equipped with a defoaming pump 5, and this and a nozzle 12 in the pretreatment tank 1 are connected through a pipe line 7. One of the nozzles 12 is mounted at an angle of about 70 degrees to the horizontal plane, and the other two at an angle of about 30 degrees, and the water spray from this latter nozzle draws a significant amount of processable material onto the screen. It will be disassembled before hanging.

The treated water in the sedimentation tank is guided by the pump 5 through the pipe 7 to the pretreatment tank, and is sprayed from a nozzle to hit the waste on the screen 13. The waste that can be treated is decomposed and sent to the crusher 2. Therefore, it is advisable to remove only vinyl, solid materials, etc. that are not destroyed by this pressure water spraying during maintenance and inspection.

Furthermore, more effective waste treatment can be achieved by setting the time interval of watering using a timer or by stopping watering during nighttime hours when there is little inflow of wastewater.

Next, we will discuss the removal effect of watering.

(1) Conventional method Water pressure...◆・φ・0.7kg/cmL Vinyl hose number φ013mmφ When using a vinyl hose crushed to about 172, flow rate v = = cf21 lower = o, sOy "■ σ = 9.4 m/s C: Nozzle coefficient = 0.8 g double force acceleration h: Position head flow rate Q = AV = π/4 x sail00652X9.4 = 0.0003 m"/s A: Cross-sectional area density ρ = 1000/9.8kg5"/go, so impact force F = ρQV =: 1000/9.8 cm” nozzle...◆
...A=0.00006m2 Nozzle discharge amount...φ
1 t5Ps 1 hour 12.2GPM From the conditions, flow rate Q = = 0.77J! /s =0.00077m' /s Flow velocity V=Q/A =0.0007710.00006 =12.8m/s Impact force F=ρQV =1000/9.8X0.00077 X12.8 =1. Okg Since the force is dispersed depending on the watering angle, the required number of nozzles is determined by the watering angle. Effective cleaning can be achieved by installing the required number of nozzles thus determined.

A comparison was made between the conventional method and the method of the present invention during periods when relatively a large amount of sewage flows in, such as Saturdays and Sundays.

Conventionally, 0.5 to 1.0 kg was required to remove impurities per day, but according to this method, only 0.2 to 0.3 kg was required per day. Conventionally, the screen cleaning time was 20 to 3
Whereas it took 0 minutes, according to this method, it only took 10 to 15 minutes, reducing the time by about half.

C. Effects of the Invention According to the present invention, it is possible to save labor and time for cleaning the screen, and moreover, it is possible to effectively remove processable materials, and therefore, the inflow of wastewater is smoother and overflow is prevented. This has various effects, such as reducing the occurrence of pests in the pretreatment tank and saving labor and time for removing dirt during maintenance and inspection.

[Brief explanation of drawings]

Fig. 1 is a process diagram of the method of the present invention, Fig. 2 is a front sectional view of the souffle chamber, Fig. 3 is a plan view thereof, Fig. 4 is a right side sectional view of the same, and Fig. 5 is a process diagram of the conventional method. It is a diagram. 1=Pre-treatment tank, 2=Crusher, 3=Processing tank, 5=Defoaming pump, 7=Pipeline, 12=Water nozzle, 13=Screen,
31=adjustment tank, 32=aeration tank, 33=settling tank, 34=
Sterilization tank. =8-

Claims (1)

[Claims] The water treated in the treatment tank including the adjustment tank and the aeration tank is returned to the pre-treatment tank using the defoaming pump of the treatment tank, and the water is sent to the screen from the watering nozzle in the pre-treatment tank. A sewage treatment method in which the wastewater is injected to decompose the treatable materials on the screen and sent to a crusher located between the pre-treatment tank and the treatment tank.