JPS60183083A - Sewage treatment apparatus - Google Patents

Abstract

PURPOSE:To enable the discharge of only a supernatant water by preventing scum from flowing into a discharge pipe, by providing a scraping apparatus in the vicinity of the discharge pipe and scarping up scum on a water surface before a discharge process. CONSTITUTION:In a treatment tank 1, an aeration process, a precipitation process for stopping the blow-in of air to precipitate sludge in a liquid and a discharge process for falling a discharge pipe to a water surface part to discharge a supernatant liquid are repeated in one cycle to perform the activated sludge treatment of inflow sewage. In this case, a scraping-up apparatus 7 is moved to a horizontal direction after the completion of the aeration process and before the discharge process and scum on a water surface is scraped up to the direction opposite to the discharge pipe 3 to prevent the inflow of the scum to the discharge pipe 3. Furthermore, because the float 8 of the scraping-up apparatus 7 is supported in a state freely movable to an up-and-down direction by a support plate 10, the scum on the water surface is effectively scraped up corresponding to the water level of sewage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sewage treatment device capable of scraping up scum on the water surface and discharging only the supernatant liquid.

Conventionally, in a batch-type activated sludge treatment apparatus, the sedimentation supernatant liquid is discharged after the precipitation step, but at this time, scum may be floating in the treatment tank.

The supernatant liquid is then discharged through a discharge pipe that moves up and down, but at this time, the scum baffle (
Float) completely prevents scum from entering. However, the conventional method has a drawback that when the scum baffle descends above the water surface, the scum present between the discharge pipe and the scum baffle flows into the discharge pipe and is discharged.

In order to solve the above-mentioned drawbacks, this invention prevents the flow of scum into the discharge pipe by providing a scraping device near the discharge pipe that collects all the scum on the water surface before the discharge process, thereby preventing the scum from flowing into the discharge pipe and discharging the supernatant liquid. The purpose of the present invention is to provide a sewage treatment device that can discharge only wastewater.

An embodiment of the present invention will be described below with reference to the drawings.

1 and 2, at the bottom of each treatment tank 1, an aeration device 2 for blowing air into wastewater in an aeration process is arranged. This aeration device 2 is normally switched and controlled by an aeration processor (not shown), but at this time, it is preferable to use one that is less likely to clog, such as a jet aeration device that spouts a gas-liquid mixture.

Discharge pipe 3 for discharging supernatant liquid during the discharge process following the precipitation process
is attached to a discharge pipe 5 which is rotatably connected to the shaft pipe 4, and a free end of this discharge pipe 5,
It is composed of an overflow pipe 6 having an open overflow port 6a.

Therefore, when the overflow pipe 6 descends below the water surface, the supernatant water in the treatment tank 1 flows into the overflow pipe 6 through the overflow port 6a, and is discharged to the outside via the shaft pipe 4. In addition, when the overflow pipe 6 is rotated by a rotating means (not shown) so as to be at a position higher than the liquid level, the liquid in the processing tank 1 is not discharged.

In this invention, in particular, a scraping device 7 is arranged near the discharge pipe 3 to scrape up scum on the water surface after the aeration process and before the discharge process. The raking device 7 is formed to be able to reciprocate in the horizontal direction (the direction of the arrow (A)). ) direction).

Next, let's talk about how this invention works! li! I will clarify.

Inside the treatment tank 1, one cycle consists of an aeration process, a settling process in which air blowing is stopped to settle the sludge in the liquid, and a discharge process in which the discharge pipe 8 is lowered to the water surface and the supernatant liquid is discharged. This operation is repeated to treat the inflowing sewage that is supplied continuously or at any time with activated sludge. Further, the sludge in the treatment tank 1 is extracted at an appropriate time.

Here, after the aeration process is completed and before the discharge process, the raking device 7
is moved in the horizontal direction to scrape up scum on the water surface in one direction (opposite direction to the discharge pipe 3) to prevent scum from flowing into the discharge pipe 3. Furthermore, since the float 8 of the raking device 7 is supported by the support plate 10 so as to be movable in the vertical direction ((b) direction), scum on the water surface can be effectively raked up in accordance with the water level of the sewage. .

3 and 4 show other embodiments of the scraping device 7,
It is rotatably supported by the discharge pipe 3 and lands to the left of the vertical direction (
(See Figure (a)). A raking float 11 is attached with a raking weight 2, and a scum rotation prevention plate 13 is attached to the discharge pipe 8.
is provided.

According to the above-mentioned configuration, when moving to the discharge process after the precipitation process is completed, first, the discharge pipe 3 starts descending as shown in FIG. 4. At this time, the scraper 70-to 11 is connected to the discharge pipe 3.
As shown in Fig. 4, it moves to the left on the water surface due to buoyancy, scrapes up scum on the water surface in the opposite direction to the discharge pipe 3, and performs the first implementation. As in the example, mixing of scum into the discharge pipe 3 is reliably prevented. The scum wrap-around prevention plate 13 can also prevent scum from flowing in from the back of the discharge pipe 3.

5 and 6 also show other embodiments of the raking device 1, which include a pair of float support arms 14 fixed on both sides of the discharge pipe 30, and movably engaged with the long holes 11 of the float support arms 14. The combined float 15 and a pair of float drive arms 1 that open and close the float 15 along the elongated hole 148
6.

As shown in FIG. 6, this float drive arm 16 has one end fixed to 70-)+5 and the other end engaged with a base frame elongated hole 17 fixed to the processing tank 1 so as to be movable in the vertical direction. are doing.

Therefore, for example, if the end of the float drive arm 16 is moved along the base frame elongated hole 1-7 by rotating the screw 18,
As shown in FIG. 6, as the float 15 opens and closes,
A relative positional change occurs between the float 15 and the discharge pipe 3, and the discharge pipe 3, which is supported by the buoyancy of flow +5, moves up and down.

Therefore, during the aeration process and precipitation process, as shown in FIG. 6(a), the flow +5 is maintained near the discharge pipe 3, and the discharge pipe 3 is supported above the water surface. Next, after the precipitation process is completed, when the float support arm 16 is lowered along the base frame elongated hole 17 by the motor 18, the discharge pipe 8 moves below the water surface, and overflow/discharge is performed.

At this time, as shown in Figure 6 (b), since the flow +5 moves in the opening direction, the scum in the vicinity of the discharge pipe 3 is scraped up to the side, so that mixing of scum can be reliably prevented and the discharge Processes can be started and ended at the same time.

Note that the raking device 1 is not limited to the above-mentioned embodiment, and may have any structure as long as it is capable of raking up scum on the water surface after the aeration step and before the discharge step.

As described above, according to the present invention, by providing a scraping device that scrapes up scum before the discharge process, it is possible to prevent scum from entering the discharge pipe and to discharge only the supernatant liquid, which is an extremely excellent effect. There is.

[Brief explanation of drawings]

Fig. 1 is a plan view of one embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view of the same, Fig. 3 is a front view of the discharge pipe, Fig. 4 is an explanatory diagram of the same operation, and Fig. 5 is a plan view of an embodiment of the invention. FIG. 6 is a plan view of the main parts of this embodiment, and FIG. 6 is an explanatory diagram of the operation of another embodiment. 1... Processing tank, 3... Discharge pipe, 7... Scraping device. Patent applicant Nishihara Environmental Health Research Institute Co., Ltd. Figure 1 Figure 3

Claims (1)

[Claims] A treatment tank that repeats an aeration process, a precipitation process, and a discharge process;
A raking device is installed in the treatment tank to scrape up the scum on the water surface after the aeration process is completed and before the discharge process, and a raking device is installed near the raking device to scrape up the scum on the water surface after the scum is scraped up. , and a discharge pipe that discharges only supernatant liquid.