JPS5910395A - Biological treatment device using 6-shaped water channel - Google Patents

Abstract

PURPOSE:To remove efficiently a BOD component and phosphorus by admitting the return sludge and water to be treated obtd. in a settling sepn. tank into a device, and subjecting the same to an anaerobic microbial treatment then circulating the same in an annular water channel and subjecting the sludge and water to an aerobic microbial treatment. CONSTITUTION:Water to be treated is admitted into a device through an inflow pipe 7 for the water to be treated and the forward end of an inflow water channel 2, and the sludge separated by a settling sepn. tank 3 is admitted from the forward end of the inflow water channel through a return sludge pipe 6 and the pipe 7. A mixture thereof is treated in an anaerobic zone B where part of the BOD component thereof is taken into the sludge. The water to be treated arrives at one end of an annular water channel 1 and joins with the water system circulating in the channel 1, whereby the water is treated aerobically. While the water circulates in the zone A, the BOD component taken into the sludge and the BOD component in the water are acid decomposed and the phosphorus in the water is taken into the sludge.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a conventional annular water groove. This relates to the improvement of so-called oxidation ditches, and relates to a biological treatment device that removes phosphorus contained in water as well as BOD components with a simple device.

A treatment facility called an oxidation ditch has recently been reviewed as a method of sewage treatment facilities for small-scale treatment plants.

This processing equipment has been used for a long time, and BO
Usually, a water groove from which component D is to be removed is formed in an annular shape with a retention volume of 24 hours, and the water to be treated flows in from a certain point in the annular groove. Rotate the rotor, etc. in one or two locations.

It dissolves air in the water, provides water flow to the water groove, and allows treated water to flow out from other points in the water groove. In this way, when the water to be treated is supplied to the water groove and the water in the water groove is circulated, the BOD components in the water to be treated are oxidized and decomposed by aerobic microorganisms, and treated water from which BOD components have been removed can be obtained. I can do it.

Further, the treated water is then treated in a sludge sedimentation separation tank to remove sludge from the treated water, disinfected, and then released.

In the oxidation ditch, a small amount of water to be treated flows into a relatively large-capacity water groove and is then processed while being circulated.
Resistant to flow rate fluctuations and BOD load fluctuations, and does not cause bulking.

In addition, it does not require particularly sophisticated operation management, the structure of the device is simple, the construction cost is low, and it is suitable for small-scale sewage treatment.

On the other hand, in recent years, eutrophication in closed water systems such as lakes and marshes has become a problem, and the necessity of removing phosphorus along with BOD components has been discussed. Can not.

The present invention skillfully combines the principle that sludge of a type that accumulates excessive phosphorus will proliferate when activated sludge is cultured under anaerobic and then aerobic conditions, and an oxidation ditch, using a simple device. The object of the present invention is to provide a device for removing BOD components and phosphorus.

That is, the present invention consists of a 6-shaped water groove in which one end of an annular inflow groove that is an anaerobic zone is connected to an annular water groove that is an aerobic zone, and a sludge sedimentation separation tank. The return sludge and water to be treated from the sedimentation separation tank flow in from the other end and are first treated with anaerobic microorganisms, then the water to be treated is circulated through the annular water groove for aerobic microbial treatment, and then circulated. 6-shaped water, characterized in that treated water of the same volume as the amount of water flowing into the inflow water groove is taken out from the annular water groove, and the sludge in the treated water is separated into solid and liquid by the sludge sedimentation separation tank. This invention relates to a biological treatment device using grooves.

The present invention will be explained in detail below with reference to the drawings.

The drawing is a plan explanatory diagram of a flow that is an example of an embodiment of the present invention.This device has an annular water groove 1 that maintains an aerobic zone A connected to an acyclic inflow groove 2 that maintains an anaerobic zone B. It consists of a letter-shaped water groove and a sludge sedimentation separation tank 3. In the annular water groove 1, a rotor 4 whose rotating axis intersects at right angles to the water flow is placed downstream from the connection part with the inflow water groove 2, for example, and is rotated half submerged in the water surface to circulate within the annular water groove l. Air is dissolved in the flowing water to maintain aerobic conditions, and a water flow shown by the arrow is provided in the annular water groove l. Also, one end of the annular water groove l and the sedimentation separation tank 3
The sludge separated in the sedimentation separation tank 3 is mixed into the treated water inflow pipe 7 via the return sludge pipe 6. Note that a blow pipe 8 for excess sludge is branched and connected to the return sludge pipe 6. In addition, the inflow water groove 2 maintains anaerobic properties as described above.

The degree of anaerobicity is at least 0, lp with dissolved oxygen.
It is necessary to keep it below pm as O. For this purpose, the upper part of the inflow water groove 2 is completely sealed and isolated from the outside air. Further, a stirrer (not shown) is installed in the inflow water groove 2 to thoroughly mix the water to be treated and the returned sludge.

Note that the annular water groove 1 and the inflow water groove 2 are made of steel plates.

It may be an above-ground tank made of concrete, or it may be a semi-underground or underground tank.

Next, the processing method of the apparatus of the present invention will be explained.

First, the water to be treated flows from the tip of the inflow groove 2 from the water inflow pipe 7, and the sludge separated by the sedimentation separation tank 3 is returned to the sludge pipe 6. The water to be treated flows through the inflow pipe 7 in slurry form from the tip of the inflow groove. These treated water and returned sludge become a mixture and flow through anaerobic zone B as shown by the arrow, but in this anaerobic zone B, some of the BOD components in the treated water are incorporated into the sludge. Also, the sludge accumulated in the sludge is prevented and flows into the water of the anaerobic zone B, where it joins the water system circulating through the annular water groove I and undergoes aerobic treatment. While circulating through this aerobic zone A,
It oxidizes and decomposes BOD components incorporated into sludge and BOD components in water.

In addition, phosphorus in the water is taken into the sludge.

In addition, the amount of water flowing into the inflow water groove 2 from the treated water inflow pipe 7 through the treated water take-out pipe δ from the other end of the circulating annular water groove l, that is, the amount of water to be treated and the return sludge. The same amount of treated water as the total amount of water is taken out, the sludge in the treated water is separated by the sedimentation separation tank 5, and the supernatant water is sterilized and discharged. On the other hand, the sludge settled in the lower part of the sedimentation separation tank 3 is circulated through the return sludge pipe 6 to the water inlet pipe 7 to be treated, and at this time, excess sludge is blown away through the blow pipe 8. This surplus sludge contains a large amount of the above-mentioned substances, and therefore, by blowing the surplus sludge, the mass balance of the system can be maintained.

As explained above, the present invention is capable of removing BOD components and phosphorus from water to be treated with an apparatus having a simple structure, is resistant to fluctuations in flow rate and BOD load, and does not cause bulking.

Since it still requires particularly sophisticated operation management, it is most suitable for small-scale sewage treatment.

The present invention will be described in detail below.18 As shown in the embodiment drawings, an annular water groove with a waterway width of 2 ocb m and a capacity of 607 is connected to an inflow water groove with the same waterway and water depth and a capacity of 207. An experimental device consisting of an annular water groove and a sludge sedimentation separation tank was manufactured, and an agitator with a propeller diameter of 5 was attached in the inflow groove, and a rotor diameter of 5 was installed downstream from the connection between the annular water groove and the inflow groove. A 6 crn Kessner type rotor was installed. The upper part of the inflow water groove was sealed and isolated from the outside air.

Using such an experimental device, the average BOD 150 Rf/as o/t and the average PO from the tip of the inflow water groove were calculated.
, -P4tv/L, pH 6-91 water temperature 18℃ water to be treated flows in at a rate of 1°t/H-20t/H, and return sludge from the sedimentation separation tank is transferred to the ML of the annular water groove and the inflow water groove.
The solution was flowed so that the SS concentration was on average 2,400 μ/l, and the treatment was carried out while driving the stirrer and rotor.

As a result, the treated water became stable after approximately one month of treatment, and the BOD of the treated water at the outlet of the inflow water channel was 25 W/t, the BOD of the supernatant water of the sedimentation separation tank was 12"f/l, and the ,
-p temporarily increased to 35 gf/l in the inflow water groove, but decreased to 0.4 ff//- in the supernatant water of the settling tank.

[Brief explanation of the drawing]

The drawing is a plan explanatory diagram of a flow that is an example of an embodiment of the present invention. l ” + annular water groove 2... Inflow water groove 3... Sedimentation separation tank 4... Rotor 5... Treated water take-out pipe 6... Return sludge pipe 7... Treated water inflow pipe
8...Blow tube A...Aerobic zone B...Anaerobic zone-9-

Claims (1)

[Claims] A 6-shaped water groove that connects one end of the aerobic zone (an annular water groove) to the anaerobic zone (non-circular inflow groove), a sludge sedimentation separation tank, and the other end of the inflow water groove. The return sludge obtained in the sedimentation separation tank and the water to be treated are first treated with anaerobic microorganisms, and then the water to be treated is circulated through an annular water groove to be treated with aerobic microorganisms. Take out the same volume of treated water as the amount of water that flowed into the inflow water groove from the water groove,
A biological treatment device using six-shaped water grooves, characterized in that the sludge in the treated water is separated into solid and liquid by the sludge sedimentation separation tank.