JPS607997A - Process and apparatus for purifying filthy turbid water in anaerobic and aerobic treating tank using underwater stirring - Google Patents

Abstract

PURPOSE:To perform optimum microbiological treatment using only one stirrer by performing purification of filthy turbid water using anaerobic microorganism and purification of filthy turbid water using aerobic microorganism while changing stirring speed for the filthy turbid water to suit to respective purification condition. CONSTITUTION:Sitirring blades 4 for causing circulatory flow are provided pivotally and freely rotatably to the midway of a passage of filthy and turbid water directing to an exhaust port 3 from a suction port 2 of a pressurized chamber 1. A variable speed motor 6 installed with a pole change motor and invertor, etc. capable of freely changing the rotational speed for driving the stirring blades is connected to the shaft center of the stirring blades 4 interposing a reduction gear 5 of a fixed change gear ratio. By operating the motor 6 on an external operating board, the rotational speed of the motor 6 is changed to obtain rotational speed suited to conditions of the quality of the filthy and turbid water.

Description

[Detailed Description of the Invention] Technical Field> The present invention relates to an anaerobic tank and an aerobic tank using underwater stirring for denitrification and dephosphorization of various polluted waters such as sewerage, human waste treatment, and industrial wastewater. The present invention relates to a method for purifying polluted water in a tank and an apparatus therefor.

<Prior art> In order to prevent water pollution caused by eutrophication in lakes, rivers, and other closed water bodies, sewage purification (secondary treatment) is necessary in the sewage treatment process for sewage, human waste, industrial wastewater, etc. It is now necessary to not only carry out this process, but also to carry out denitrification and 1-visible phosphorus treatment (tertiary treatment). Specific measures include wastewater purification (secondary treatment) using activated sludge method, cyclic denitrification,
Dephosphorization methods, endogenous denitrification, dephosphorization methods, low dilution γP two-stage activated sludge methods, etc. have been adopted as mainstream technologies.

Therefore, in the mainstream technology of Section 1, the residence time of sewage is required to be more than twice that of the conventional standard activated sludge treatment due to the reaction rate of organisms in the treatment process, and the aeration tank capacity is twice as long. As a result, power consumption increases significantly. In addition, all of them require an anaerobic tank or an aerobic tank, and these tanks can be operated alternately or used singly to purify wastewater and carry out denitrification and dephosphorization treatments.

Therefore, in an aerobic tank, the air is made finer, has sufficient diffusion,
Complete treatment cannot be achieved unless conditions such as efficient gas-liquid contact, uniform pollution concentration, and prevention of sludge sedimentation are met. For this purpose, it is necessary to maintain the pumping propeller of the stirrer at a predetermined number of rotations to ensure stirring strength, and a predetermined number of times is required. On the other hand, in the hatching tank, we thought that it was necessary to provide sufficient agitation rotation without ventilation, so we prepared multiple processing tanks without dedicating each of the above types. Either one of them would be used as an aerobic tank and the rest would be used as an anaerobic tank, or one tank would be alternately switched between an aerobic tank and an anaerobic tank. Therefore, the aerobic tank and the anaerobic tank each use the same agitator and the same driving force, and the anaerobic tank and the aerobic tank can be used interchangeably as required.

However, in the case of anaerobic treatment, this treatment method is inefficient because it does not provide optimal conditions for stirring the tank, and it requires a lot of electricity! 1J, which led to a pale yellow color and was uneconomical.

As a result, reducing the enormous amount of power consumed by the conventional processing techniques described above has become an urgent issue in terms of cost savings.

<Purpose> The purpose of the present invention is to obtain optimal conditions for aerobic biological treatment and anaerobic biological treatment using a single stirrer by arbitrarily changing the stirring speed in the treatment tank.

<Structure of the Invention> The present invention provides an I' for an anaerobic tank and an aerobic tank using underwater stirring, in which the drive speed of the stirrer in the processing tank is arbitrarily changed.
jαi water purification treatment method and device.

<Example> Hereinafter, the present invention will be described in detail with reference to an example. An example of an agitator installed at the bottom of an anaerobic tank or an aerobic tank is a system that connects a polluted water inlet (2) and an outlet. In a pressurized chamber (1) having an outlet (3), from the suction port (2) to the discharge port (
A stirring blade (4) that generates a circulating flow is freely rotatably installed in the middle of the contaminated water passage toward 3), and rotation is applied to the stirring blade (4) on the axis of the stirring blade (4). , and a speed conversion motor (6) having a speed change device such as a pole change motor (pole number conversion motor) that can freely change the rotational speed, or an inverter or a transmission, and a speed reduction gear (5) with a constant speed ratio in between. By operating the speed converting motor (6) on an external operation panel, the rotational speed of the motor can be changed to obtain a rotational speed that meets the conditions of polluted water quality.

Next, as mentioned above, it is well known that the processing conditions for an aerobic tank require sufficient air and stirring power, but the appropriate conditions for processing an anaerobic tank were not sufficiently known. The relationship between this and the denitrification effect will be investigated.

■ Experimental equipment treatment tank size -5, OX 16.5 x 4.0 [
7) 2]... 4 unit configuration capacity j4-330 [2) l] Stirrer type - F type stirrer 3.7 [KW] (rotation speed fixed type) % type % [] (rotation speed variable type) 2. Experimental method: Arrange the equipment described in 1 as shown in Figure 2, with four consecutive tanks A.

B, C, and I) are configured, tanks A and D are aerobic tanks (aeration tanks), and tanks 13 and 1) are anaerobic tanks. This study was carried out by comparing the rate of reduction of nitrate nitrogen in polluted water using the endogenous denitrification method.

The measurement points were points 1 to 9 in tank B shown in FIG.

3. Experimental conditions 4. Experimental results Tables 1 to 4 show the results of measuring the mud concentration distribution in the tank with respect to the relationship between depth and position under each condition.

(1) Sludge concentration distribution table in the tank IRUN-1 Table 2RUN-2 Table 8RUN-3 Table 4RUN-4 5 Denitrification rate A comparison of the denitrification rate for each experimental condition is as follows.

As mentioned above, this experiment looked at how the fluctuation of stirring power affects anaerobic biological treatment, and the volume aX stirring power was set from 0.034 KW/ypf to 0.0023 KW/n.
These are the results of measuring the sludge concentration and denitrification rate when changing the concentration up to f.

As can be seen from this, regarding the distribution of sludge concentration, high concentrations were observed at the deepest water depths at measurement points 1 and 7 (Figure 3) in RUN-2. Although some sludge has been deposited in this area, there is no such large deviation in other areas, and it is clear that all parts of the tank are being stirred almost uniformly. Similarly, the fluctuation 11'' was in the range of 74% to 89%, and no particularly large fluctuations were observed; rather, the denitrification rate tended to be higher as the volumetric stirring force was smaller.

As is clear from the above, it has been found that reducing the stirring power does not have a particularly large effect on the denitrification effect, and as a result, a comparison with the conventional case in terms of power consumption And ever possible.

<Saku Kawa> The speed conversion motor (6) of the agitator installed at the bottom of the polluted water treatment tank is used to change the agitation speed according to the purpose of treatment.For example, to perform aerobic biological treatment, While supplying air, the sludge settles, and a constant high speed rotation is applied to ensure sufficient gas-liquid contact.Also, to perform anaerobic biological treatment, aeration is stopped and the rotation speed of the agitator speed conversion motor is adjusted. It is possible to treat the sludge by lowering the stirring speed and providing a stirring speed that matches the conditions such as the temperature and concentration of the sludge.

<Effects> As mentioned above, by changing the stirring speed of the stirrer according to the purpose of wastewater treatment, unnecessary power can be reduced, wasteful power consumption can be eliminated, and costs can be saved. .

Furthermore, since the stirring speed can be changed in terms of equipment, the equipment can be simplified because it can be adapted to the specific processing conditions by simply using a standard stirrer. It is extremely economical.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate embodiments of the method and apparatus of the invention. FIG. 1 is a longitudinal sectional view of the main part of the device of the present invention. FIG. 2 is a schematic plan view of a multiple treatment tank used in the experiment of the method of the present invention. Figure 3 is a schematic plan view of the processing tank showing the data collection points 01...
- Pressurizing chamber, 4... Stirring blade, 6... Speed conversion motor. Applicant Hanshin Power Machinery Co., Ltd. Agent No Rumi Suzuki

Claims (1)

[Claims] ■ Purification of polluted water by anaerobic organisms and purification of polluted water by aerobic organisms by changing the stirring speed of polluted water to suit the respective purification conditions. A method for purifying contaminated water in an anaerobic tank and an aerobic tank using underwater agitation, which is characterized in that two types of purification processes with different conditions are combined. 2. The speed of the drive source for agitating the polluted water is changed to suit the purification conditions of polluted water carried out by sickling organisms and polluted water carried out by aerobic organisms to suit the respective purification conditions. A polluted water purification device using an anaerobic tank and an aerobic tank using underwater agitation, which is characterized in that it can perform two types of purification processes with different conditions.