JPH039836Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention is a waste liquid treatment tank for anaerobically treating organic waste liquids such as industrial wastewater, sewage, human waste, etc. using the upward flow sludge blanket method. This is related to the improvement of

<Prior art> When waste liquid containing a relatively high concentration of BOD components is treated using anaerobic microorganisms, a waste liquid treatment tank using the sludge blanket method as shown in Fig. 2 has traditionally been used. It is being

That is, there is a blanket zone 2 for anaerobic microorganisms in the lower part of the tank 1, and in the upper part of the blanket zone 2, there is a shielding plate 3 and a conical or pyramid-shaped collection located above the shielding plate 3. A separator 5 having a collection chamber S that widens toward the end and is made of a plate 4 is installed, and a generated gas extraction pipe 6 is installed in the separator 5.
At the same time, a processing liquid outflow pipe 7 is connected to the upper part of the tank 1.
The organic waste liquid flows in from the waste liquid inflow pipe 8 that communicates with the bottom of the tank 1, and the waste liquid is brought into contact with the blanket zone 2, where BOD components in the waste liquid are removed by anaerobic treatment. It is something to do. Note that gases such as methane gas and carbon dioxide gas are generated by the anaerobic treatment, but the generated gases become bubbles and leave the blanket zone 2 together with the treatment liquid, resulting in compensation for the end expansion as shown by the dotted arrow line in the figure. Collected by a separator 5 having a collection chamber S,
The generated gas is taken out from the tank 1 through the take-out pipe 6,
On the other hand, the processing liquid is allowed to pass through the separator 5 and flow out from the processing liquid outflow pipe 7 at the upper part of the tank 1, as shown by the solid arrow line.

Note that the treatment liquid contains some suspended solids, and some of the suspended solids are allowed to settle in the collection chamber S of the separator 5, and the other part is allowed to settle above the separator 5. It is made to fall downward through the slope of the collecting board 4. Further, the pressure of the generated gas in the collection chamber S of the separator 5 is adjusted to form a liquid level L in the collection chamber, and only the generated gas is taken out from the generated gas extraction pipe 6.

<Problem to be solved> The waste liquid treatment tank using the sludge blanket method described above is capable of high-load treatment compared to the standard anaerobic activated sludge method, and is also easier to fill than an anaerobic fixed bed. Although it has the advantage of being relatively inexpensive to construct because no materials are required, it has the following drawbacks.

That is, when the gas generated by the anaerobic treatment becomes bubbles and leaves the blanket zone 2, the bubbles enclose suspended solids, and the suspended solids float to the water surface L in the collection chamber S. , which causes the problem that it gradually forms a layer and accumulates on the water surface L.

In such a state, the collection of generated gas by the separator 5 is impaired, and some of the bubbles enclosing the suspended solids pass through the separator 5 and enter the upper part of the tank 1, causing suspension of the processing liquid. This causes various problems such as an increase in the amount of turbid solids.

The purpose of the present invention is to solve such drawbacks in conventional waste liquid treatment tanks and to prevent suspended solids from floating on the water surface L in the collection chamber S.

<Means for Solving the Problems> The present invention introduces waste liquid containing organic matter from the bottom of a tank having a blanket zone for anaerobic microorganisms, brings the waste liquid into contact with the blanket zone, performs anaerobic treatment, and The three-phase gas-liquid-solid mixture of generated gas bubbles, treated liquid, and suspended solids that has passed through the ket zone is passed through a separator consisting of a collecting chamber that widens at the end, the generated gas is collected by the separator, and the treated liquid is The present invention relates to a waste liquid treatment tank in which waste liquid is taken out at the upper part of the tank, characterized in that an inclined plate or an inclined pipe is installed in a gas-liquid-solid three-phase mixing zone between the blanket zone and the separator. .

FIG. 1 is an explanatory diagram showing an example of an embodiment of the present invention, and the present invention includes an inclined plate 9 in a three-phase gas-liquid-solid mixing zone between a blanket zone 2 and a separator 5 in a conventional waste liquid treatment tank. It was installed. Note that the other parts are the same as those of the conventional one, so the explanation will be omitted.

<Function> When treating organic waste liquid in this invention,
Organic waste liquid flows in from the waste liquid inflow pipe 8 and is brought into contact with the blanket zone 2 of anaerobic microorganisms. The BOD components in the waste liquid are decomposed by the action of anaerobic microorganisms in the blanket zone, and at the same time gases such as methane gas or carbon dioxide gas are generated. The generated gas forms bubbles and leaves the blanket zone 2, entrapping some of the suspended solids in the bubbles together with the processing liquid and suspended solids. When passing through the tilted plate 9, the air bubbles enclosing the suspended solids are destroyed by the collision between the tilted plate 9 and the water flow, and the suspended solids move downward as shown by the dash-dotted arrow line in the figure. The air bubbles that settle and have the suspended solids removed in this manner rise as indicated by the dotted arrow line and are collected by the separator 5. Further, the processing liquid from which air bubbles and most of the suspended matter have been removed passes through the separator 5 as shown by the solid arrow line, and flows out from the processing liquid outflow pipe 7.

The inclined plate 9 used in the present invention can be similar to the inclined plate used for promoting solid-liquid separation in a general coagulation-sedimentation apparatus, and the inclined plate 9
An installation height of about 0.5 to 1 m is sufficient. Incidentally, instead of the inclined plate 9, an inclined pipe having a similar function can also be used.

<Effects> As explained above, the present invention uses the function of the inclined plate or inclined pipe installed in the three-phase gas-liquid-solid mixing zone between the blanket zone 2 and the separator 5 to eliminate air bubbles that enclose suspended solids. Since the separator 5 is destroyed, the suspended solids do not float to the water surface L in the collection chamber S, and the generated gas is effectively collected in the separator 5.

Furthermore, the action of the inclined plate or inclined tube of the present invention is effective in destroying the bubbles entrapping the suspended solids as described above, as well as promoting the settling of the suspended solids themselves.

As a result of the above effects, the number of microorganisms in the blanket zone 2 increases, stability against changes in water quality and water amount increases, and the amount of suspended solids in the treatment liquid can be reduced.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a conventional waste liquid treatment tank. 1...tank, 2...blanket zone, 3...
Shielding plate, 4... Collection plate, 5... Separator, 6...
... Generated gas take-off pipe, 7... Processing liquid outflow pipe, 8
...Waste liquid inflow pipe, 9...Slanted plate, S...Collection chamber,
L...Water surface.

Claims (1)

[Scope of utility model registration request] A waste liquid containing organic matter is introduced from the lower part of a tank having a blanket zone for anaerobic microorganisms, and the waste liquid is brought into contact with the blanket zone to perform anaerobic treatment, and the generated gas bubbles that have passed through the blanket zone and the treated liquid are In a waste liquid treatment tank, a three-phase gas-liquid-solid mixture of suspended solids and suspended solids is passed through a separator consisting of a collecting chamber that widens toward the end, the generated gas is collected by the separator, and the treated liquid is taken out at the upper part of the tank.
A waste liquid treatment tank characterized in that an inclined plate or an inclined pipe is installed in a gas-liquid-solid three-phase mixing zone between the blanket zone and the separator.