JPS6339683A - Treating device for polluted water - Google Patents

Abstract

PURPOSE:To enable the treatment of polluted water to be changed over to a desired method to enhance working efficiency by communicating the upper part of a treating tank, dividing the lower part thereof with partition walls to form a floating and settling tank as well as a settling separation tank. CONSTITUTION:A treating tank 16 consists of a floating and settling tank 16a and a settling separation tank 16. Mixed water from a flock electric charge adjusting tank 13 and foams from a line mixer 15a are fed simultaneously into a pipe 16a-1 installed in the center of half of the water depth of the floating and settling tank 16a, and run off into the tank 16a through through-holes to float up the light-weight flocks and settle down heavy flocks by gravity to be separated. On the other hand, flock mixture water from the electric charge adjusting tank 13 is sent into a flock aging tank 6 and treated, and then supplied to a settling separation tank 16b to be settled and separated. By said process, separation by floating and settling soil substances or simply by settling can be selected freely in a single tank.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a polluted water treatment device, such as an intake channel for cooling water for a turbine of a generator, its drainage channel, a dock,
Concerning equipment for treating contaminated water such as pump stations that drain rapidly increasing rainwater from sewers into rivers.

Conventional techniques may involve the withdrawal of large amounts of water. For example, a generator at a thermal power plant uses high-pressure steam to turn a turbine to generate electricity, but at this time a large amount of cooling water is used. In such cases, water is taken from the sea, for example, through an intake channel and through a screen, but at this time mud from the sea floor, oil from the sea, and plankton flow in with the seawater, causing water to be taken continuously for a long period of time. Floating substances such as water sources, plankton carcasses, and sludge, as well as settling substances such as shellfish, sediment, silt, colloids, and clay, accumulate in waterways. These pollutants clog the screen, increasing its resistance to water flow and limiting the amount of water taken. Furthermore, if a coarse screen is used, it will pollute the cooling flow path, and if it settles on the wall, it will impair thermal conductivity and reduce the cooling effect.

For this reason, the polluted substances accumulated in the intake channel are dredged, the polluted water is treated with a chemical solution to separate solid and liquid, and the water is drained, and the solid content is dehydrated and discarded. For example, as shown in Fig. 2, dredged polluted water is stored in a preliminary raw water tank 1, and is sent to a raw water tank 3 via a preliminary raw water tank 2 for adjusting according to the amount of pollutants to be treated. . Here, from the inorganic flocculant tank 4, for example, borinane (polyferric sulfate),
For example, caustic soda is injected into the raw water tank 3 from the neutralizer tank 5 to form flocs at a pH of 5.8 to 8.6. Then, the polluted water to be treated is sent to the flock aging tank 6,
Here, for example, an anionic polyacrylamide-based polymer is injected from the organic polymer flocculant tank 6a to mature the flocs, and then the flocs are put into the coagulation sedimentation separation tank 7 and allowed to settle naturally. The supernatant liquid is discharged into the sea either as is or after being subjected to biological treatment. On the other hand, the settled pollutants are scraped up by a scraper 8, and then an anionic polyacrylamide polymer flocculant, for example, is injected from an organic polymer flocculant tank 9 to strengthen the bond between the flocs, and then a dehydrating agent is used. For example, a cationic polyacrylamide-based polymer flocculant is introduced from the tank 10 to crosslink the flocs, thereby improving water separation, and the flocs are dehydrated to some extent in the granulator 11 and pelletized. This pellet is dehydrator 1
2, and is further dehydrated and removed as a polluted solid, which is then discarded.

However, in this conventional apparatus, flocs of pollutants are separated by natural settling, which not only takes time, but also may not allow floating substances such as water sources and plankton to settle.

In addition, if there are many pollutants to be treated, the coagulation sedimentation separation tank 7
In some cases, the pollutants cannot be completely treated and the processing speed must be reduced. However, this is undesirable because it causes a decrease in treatment efficiency, and if this efficiency is maintained, pollutants may be discharged into the sea without being separated, which is undesirable because it pollutes the sea.

The above was a case of intake channels, but similar problems also occur in the case of drainage channels, intake channels, near drainage channels, docks, and when treating polluted water at pumping stations when rapidly increasing rainwater from sewers is drained into rivers. There is a point.

Problems to be Solved by the Invention As mentioned above, there are problems with the conventional treatment of polluted water in intake channels, etc., in which the processing speed cannot be adjusted quickly especially when the processing load increases, and there is also the problem that floating pollution There is a problem that some substances cannot be removed, and an improvement has been desired.

Means for Solving the Problems In order to solve the above problems, the present invention provides a floc forming means for forming flocs of pollutants by subjecting polluted water to a collection process, and a floc formed by the floc forming means. The treatment means has a treatment means for treating the mixed water, and the treatment means includes a sedimentation separation tank that sediments and separates the floc-mixed water, and a sedimentation separation tank that sediments and separates the floc-mixed water, and the floc-mixed water flows out together with air bubbles into an intermediate water depth position, or the floc-mixed water flows out. After that, a flotation/sedimentation tank is installed at the top of the treatment tank, which can selectively perform flotation/sedimentation separation by supplying air bubbles to this outflow position to perform flotation and sedimentation, and sedimentation separation similar to the above-mentioned sedimentation separation tank. The present invention provides a polluted water treatment device characterized in that the polluted water is provided by communicating the water and partitioning the lower part with a partition wall.

We have installed a sedimentation separation tank that can perform functional separation, so when there are many floating pollutants, we can switch to separation by both flotation and sedimentation, and use it in conjunction with separation by sedimentation alone. You can use it according to your needs.

Example Next, one embodiment of the present invention will be described based on FIG.

In the figure, the same reference numerals as those on the map indicate the same components. Reference numeral 13 denotes a flocculation charge adjustment tank, which makes the charge of the flocs formed in the raw water tank 3, for example, negative. - The floc mixed water is supplied from the power source water tank 3, and these are stirred and mixed.

Further, 15 is a pressurized water device, and a line mixer 15
Pressurized air is supplied to a from the compressor 15b, while a part of the floc mixed water is supplied from the raw water tank 3 to this mixer, and the floc mixed water and air are stirred and mixed. When pressurized air is mixed with a strong agitator such as a line mixer in this way, a large amount of bubbles are generated, and these bubbles are charged with the positive charge of the flocs from the raw water tank 3.

Further, 16 is a processing tank, which is composed of a flotation/sedimentation tank 16a and a sedimentation/separation tank 16b. The flotation and sedimentation tank 16a is provided with a pipe 16a-1 having a large number of through holes in the length direction at an intermediate position of half the water depth, and the floc mixed water from the floc charge adjustment tank 13 and the line Foam from mixer 15a is fed at the same time and these are discharged into the tank. In the floc-mixed water discharged in this way, positive air bubbles adhere to the negative flocs, which causes the lightweight flocs to float to the surface.
On the other hand, heavy flocs settle due to gravity. On the other hand, a part of the floc mixed water from the charge adjustment tank 13 is sent to the floc ripening tank 6 and treated there, and then supplied to the sedimentation separation tank 16b, where it is sedimented and separated.

The flocs floated as above are scraped by scraper 1.
6c, and on the other hand, the sediments in the flotation/settling tank 16a and the settling tank 16b are scraped up by the scraper 16d, and the solid content of these is treated as explained in FIG. Note that the suspended matter remaining in the flotation/sedimentation tank 16a without being floated or settled is treated in the floc maturation tank 6, and then sent to the sedimentation separation tank 16b, where it is sedimented and separated.

Although the water from which pollutants have been removed in this way is not shown in the figure, it is passed through a biological treatment tank in which many activated sludge layers are arranged in the flow direction. It is preferable to remove the D, C, O, and D components before discharging.

Although the flotation/sedimentation tank 16a is used for both flotation and sedimentation in the above description, it can also be used only for sedimentation and used in combination with a sedimentation separation tank. In this case, the flocs aged in the floc maturing tank 6 are supplied. In addition, although the air bubbles were charged positively and the flocs were charged negatively in the above example, they can also be charged in the opposite manner. Surfactants can also be used to provide these charges.

In addition, the position of the pipe 16a-1 is not limited to the center position of the water depth, but may also be placed diagonally on the upper side, lower side, or at an angle.

Furthermore, PAC1 sulfate band or the like can be used as a flocculant.

Also, the above supplied air bubbles to the floc mixed water, but
Air bubbles may be supplied after the floc mixed water has flowed out.

The above was a case of treating polluted water from intake channels, but when treating polluted water from drainage channels, intake channels, the vicinity of drainage channels, docks, and pumping stations where rapidly increasing rainwater from sewers is discharged into rivers. It can also be applied to

As described in detail, according to the present invention, it is possible to selectively separate pollutants by both floating and settling, or by settling only, so that when there are many floating pollutants, Separation by both flotation and sedimentation is mainly used, and when there are many sedimentary pollutants, separation is performed only by sedimentation without flotation, and the method can be used depending on the type of pollutants in the polluted water. can. Also,
Flotation and sedimentation using a flotation/sedimentation tank can float and separate lightweight flocs even if they are not buoyant, so in this case, flotation and sedimentation can be performed twice using the same area, increasing the processing speed. is significantly improved compared to sedimentation alone, making it possible to cope with increased processing loads, as well as separating floating pollutants and preventing pollution when discharging wastewater into the sea. . In this way, the efficiency of treating polluted water can be improved and high-quality wastewater can be produced.

Furthermore, flotation separation can be improved by making the charge of the flocs and the charge of the air bubbles different.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the usage state of an apparatus according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the usage state of a conventional apparatus. In the figure, 3 is the raw water tank, 13 is the floc charge adjustment tank, and 15a
16 is a line mixer, 16 is a processing tank, 16a is a flotation/settling tank, 16b is a sedimentation separation tank, and 16a-1 is a pipe. August 1, 1986

Claims (2)

[Claims] (1) It has a floc-forming means that performs chemical injection treatment on polluted water to form flocs of pollutants, and a treatment means that treats the floc-mixed water formed by the floc-forming means. The floc-mixed water is discharged together with air bubbles into a sedimentation separation tank that sedimentates and separates the water, and at an intermediate water depth position, or after the floc-mixed water is discharged, air bubbles are supplied to this outflow position for flotation and sedimentation. Polluted water characterized in that a flotation/sedimentation tank capable of selectively performing flotation/sedimentation separation and sedimentation separation similar to the above-mentioned sedimentation separation tank is provided in one treatment tank by communicating the upper part and partitioning the lower part with a partition wall. processing equipment. (2) The polluted water treatment device according to claim 1, wherein the air bubbles are formed using an ionic substance having a charge opposite to that of the flocs treated with the chemical injection.