JPS6113116Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a circulating waterway type activated sludge treatment device that utilizes the water level difference of sewage to cause sewage to flow into a settling tank without power, and to smoothly return settled sludge to a circulating waterway.

Circulating channel type activated sludge treatment equipment has been proposed in the past, which performs aeration treatment while imparting a flow rate to wastewater in a waterway, but in both cases, the treated liquid is introduced into a settling tank,
The disadvantages are that a separate power source is required to return the settled sludge, and its structure is complicated.

This invention solves the above-mentioned drawbacks and relates to a circulating waterway type activated sludge treatment device that utilizes the water level difference created by the aeration device to flow sewage into a settling tank and return the settled sludge without using any power.

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

In this invention, as shown in Fig. 1, a circulation waterway 2 is formed by a partition wall 1, and an aeration device 3 such as a Kessner brush type aerator is disposed within this waterway 2 to provide aeration while providing a circulation flow in the direction of the arrow. There is.
This aeration device 3 can be of the Kessner brush type, the gas-liquid mixture jet aeration type, or the mechanical aeration type, but all of them impart a circulating flow velocity to the wastewater by the aeration force. Therefore, the water level downstream of the aeration device 3 is the highest in the waterway.

Further, a sedimentation basin 4 is provided in contact with the circulation waterway 2. This sedimentation tank 4 may be located inside or outside the waterway 2, but in this embodiment it is provided in contact with the outer wall 1a of the straight waterway portion. As shown in FIG. 2, on one side wall of the upper part of the sedimentation tank 4, an overflow weir 5 is provided on the outer wall 1a of the circulation waterway 2 and near the highest water position for inflow of sewage using the water level difference. On the other hand, an overflow weir 6 for outflowing the supernatant liquid is provided on the other side wall of the settling tank 4, and is formed so that the supernatant liquid can be discharged to the outside via a discharge pipe 7. Note that the circulation waterway 2 and the sedimentation tank 4 may communicate with each other below the liquid surface.
In addition, the vicinity of the bottom of the sedimentation tank 4 communicates with the waterway 3 as shown in FIG. It is formed so that the sewage can be returned to the waterway 3 by pressure. In addition, the communication part 8 and the inclined part 9 of the sedimentation tank 4 transfer the settled sludge to the waterway 2.
It may have any structure, shape, etc. as long as it can be returned to the manufacturer, and may be formed as shown in FIGS. 4 and 5, for example.

According to the above configuration, the wastewater in the circulation waterway 2 is aerated while being given a circulation flow rate by the aeration device 3, but a part of the aeration mixture settles from the high water position downstream of the aeration device 3. Flows into pond 4. The aerated liquid mixture that has flowed into the settling tank 4 is subjected to sedimentation treatment, and the supernatant liquid is discharged to the outside via the overflow weir 6 and the discharge pipe 7, while the settled sludge is passed through the communication section 8 as shown in FIG. It is sent back into waterway 2. Therefore, by utilizing the water level difference in the circulation waterway 2 caused by the aeration device 3,
Since the sludge flows into the settling tank 4 and is returned, smooth sludge return can be performed without using any power, and efficient treatment can be performed.

Note that a contact material or the like may be arranged in the circulation waterway of the activated sludge treatment apparatus of this invention.

As described above, this invention has excellent effects such as smooth sludge return without using any power and extremely efficient treatment.

[Brief explanation of the drawing]

Figure 1 is a plan view of an embodiment of this invention, Figure 2 is a sectional view taken along the line X--X in Figure 1, and Figure 3 is a
-Y line sectional view, FIGS. 4 and 5 show longitudinal sectional views of other embodiments of the settling tank. 2... Circulation channel, 3... Aeration device, 4... Sedimentation basin, 5, 6... Overflow weir, 8... Communication section, 9...
Slope.

Claims (1)

[Scope of claims for utility model registration] (1) Circulating waterway 2 for treating wastewater using activated sludge
, an aeration device 3 disposed in the circulation waterway 2 for aerating the circulation waterway 2 while giving a circulation flow to the circulation waterway 2;
a settling tank 4 into which the aerated mixed liquid in the circulating waterway 2 flows from the part where the water level has become high;
and a return means for communicating the sedimentation tank 4 and the circulation waterway 2 near the bottom of the sedimentation tank 4 and returning the settled sludge to the circulation waterway 2. Circulating waterway type activated sludge treatment equipment. (2) The circulating waterway type activated sludge treatment apparatus according to claim 1, which is characterized in that the settling tank 4 is provided in the circulating waterway 2. (3) The circulating waterway type activated sludge treatment device according to claim 1, wherein the settling tank 4 is provided in contact with the outer wall of the straight portion of the circulating waterway 2.