JPH07108395B2 - Turbid water treatment method and treatment device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for treating turbid water for purifying fresh water or seawater by continuously aggregating, precipitating and solidifying suspended particles thereof.

[0002]

2. Description of the Related Art Various methods have been tried for purifying water polluted with red soil, river polluted water, river bottom sludge, pond water containing algae, etc., but a method using an inorganic flocculant. As the above, the following method is known. That is, the contaminated raw water is sequentially transferred to the first reaction tank, the second reaction tank and the coagulation sedimentation tank, and the liquid inorganic filler containing aluminum sulfate, ferrous sulfate, lime and the like and the pH adjusting agent are transferred in the first reaction tank. In addition, the suspended matter in the raw water is pin-flocked by stirring, and a liquid polymer flocculant containing polyacrylamine, polyethyleneamine, etc. is added in the second reaction tank, and the pin-locking is performed by stirring. The flocs were allowed to grow large, the flocs were allowed to settle in the flocculation settling tank, and the supernatant liquid was taken out from the upper part, while the sludge containing the above flocs was taken out from the bottom part, put it in a container, and sent it to another solidification step to solidify it. .

However, since the above-mentioned conventional method uses the inorganic coagulant, the pH adjuster and the polymer coagulant in a liquid state, a dissolving tank and a storage tank are required for each of them, and installation for them is required. There is a problem that the area is required and the cost is high. Further, since the reaction rate is slow and the growth difference of the floc in flocs is large due to the fluctuation of PH in the reaction tank, it is necessary to ensure solid-liquid separation.
The coagulation-sedimentation tank tended to be upsized. Further, since the solidification step is separated from the coagulation-sedimentation step, the sludge needs to be transported, and since the solidification is performed in a batch system, the solidified sludge redissolves.

On the other hand, recently, it has been attempted to use a carbonate aluminate salt material called a CAS agent as an aggregating agent. This CAS material is mainly composed of calcined gypsum and sulfuric acid band, and is a powdered mixture of cement, slaked lime, and soda ash. It has a lower PH dependency and a lower reaction rate than conventional flocculants. It has attracted attention because it forms a large, strong floc with a large apparent specific gravity, but since it is a powder, it is used exclusively in a batch system.
Blind to the aggregation of suspended solids in the raw water, a method of continuously a series of steps leading to solidification of the sludge from the precipitation has not been established to date.

[0005]

SUMMARY OF THE INVENTION The present invention uses a carbonate aluminate-based salt material called a CAS agent as a flocculant, whereby a series of flocculation and precipitation of suspended solids in raw water to solidification of sludge is carried out. Continuing the process, eliminating the need for a dissolving tank and a storage tank for each of the inorganic coagulant, PH adjusting agent, and polymer coagulant, which have been required until now.
It enables the downsizing of the entire equipment including the coagulating sedimentation tank, and produces solidified sludge with excellent water resistance. Moreover, not only fresh water as raw water but also turbid water of seawater, such as sediment sludge in fish farms, coastal sludge and red soil. It is intended to provide a processing method and a processing apparatus capable of cleaning deposits such as.

[0006]

[Means for Solving the Problems] The first invention is to supply the raw water supplied to the reaction tank to the raw water in the reaction tank while flowing the water in one direction.
From the flocculant tank above the reaction tank , a powdered carbonate aluminate salt material as a flocculant is dropped at a predetermined speed and stirred to cause a flocculation reaction, and the floc-containing water obtained is continuously flocculated and settled. To the bottom of the flocculation-precipitation tank, the supernatant liquid is taken out from the top of the flocculation-precipitation tank as treated water, while sludge containing a large amount of flakes is continuously taken out from the bottom of the flocculation-precipitation tank. Dehydrated and sent to a kneader while adjusting the water content, and kneaded with a powdery sludge solidifying agent whose main component is coal ash or crushed stone in this kneader to solidify the above sludge to produce solidified sludge. This is a method for treating muddy water.

A second aspect of the present invention relates to an apparatus for carrying out the above-mentioned first aspect of the invention, in which a reaction vessel capable of agitating a supplied raw water in one direction with a stirrer is installed above the reaction vessel. , A powdered coagulant containing a carbonate aluminate salt material, and a coagulant supply device for dropping the powdered coagulant into a lower reaction tank at a predetermined speed, and a center well in the center, respectively provided along the conical bottom rake is disposed flocs containing water delivered through the floc pipe from the reactor to a lower portion of the reactor so as to flow into the center well, the reactor
And the agglutination settling tank connected by the flock pipe, connected with a sludge pipe at the bottom of the agglutination settling tank, the upper
And dehydrator for dehydrating the sludge sent from the bottom of the serial coagulating sedimentation tank continuously through the sludge pipe,
A kneader equipped with a sludge hopper for continuously receiving dewatered sludge discharged from this dewatering machine, and a powdery sludge mainly composed of coal ash or crushed stone powder, which is installed above the sludge hopper. A treatment device for turbid water, comprising: a solidifying agent supply device that accommodates the solidifying agent and that can supply the sludge solidifying agent to the sludge hopper at a predetermined speed.

The aggregating agent (carbonic acid aluminate salt material) used in the above-mentioned first and second inventions is mainly composed of calcined gypsum and sulfuric acid band, and is a mixture of cement, slaked lime and soda ash (for example, Product name "P
OK-S "). The sludge solidifying agent used for solidifying the sludge is mainly composed of coal ash, for example, fly ash discharged from a fluidized bed coal boiler (for example, product number "No. 12" manufactured by Samsung Chemical Joint Stock Company).
Alternatively, the main component is crushed stone powder.

[0009]

According to the first aspect of the invention, the raw water supplied to the reaction tank reacts with the flocculant, and flocs are formed more quickly than in the case where the conventional flocculant is used. In this case, since the aggregating agent is a substantially neutral carbonate aluminate salt material and its PH dependency is small, it is not necessary to adjust the PH of the raw water, and the apparent specific gravity can be quickly increased. Large firm flock is formed. Therefore, when the floc-containing water is sent to the coagulating sedimentation tank, the flocs quickly precipitate to form sludge, which is sent to the kneader while dehydrating the sludge and kneaded with the sludge solidifying agent,
Moisture in the sludge is absorbed by the solidifying agent to efficiently obtain a clay-like hard, highly water-resistant solidified sludge. The water content of the sludge sent from the dehydrator to the kneader is
It is preferably adjusted to 50 to 90%, and if it exceeds 90%, it is necessary to use a large amount of a solidifying agent for sludge, which is uneconomical. The amount of the solidifying agent used can be appropriately set depending on the properties of the sludge.

By driving the processing apparatus of the second invention, the above first invention is implemented. That is, when raw water is sent to the reaction tank, it falls from the flocculant supply device to the reaction tank.
Stirring is performed together with the powdery flocculant, and the reaction is started with the stirring to form flocs. Then, the floc floc-containing water containing is sent through the floc pipe and the center well in agglutination settling tank, flocs precipitated downward, raked by the rake and collected in the lower end of the conical bottom It becomes sludge. Then, the sludge is removed from the bottom of the agglutination settling tank, is sent to the dehydrator through the sludge pipe, is dehydrated sent to sludge hopper after moisture adjustment is, above the solidifying agent supply It is kneaded with the powdery solidifying agent supplied from the apparatus, the moisture in the sludge is absorbed by the solidifying agent by this kneading, and the obtained solidified sludge is discharged from the discharge port of the kneader.

[0011]

EXAMPLES In FIG. 1, 10 is a vertical raw water tank,
A small reaction tank 20 is provided on the upper right side thereof, a coagulant supply device 30 is installed on the upper side of the reaction tank 20, and a coagulating sedimentation tank 40 is installed on the lower right side thereof.
A dehydrator 50 and a kneader 60 are sequentially installed on the right side of 0, and a solidifying agent supply device 70 is provided above the kneader 60. Then, the raw water tank 10, the reaction tank 20, and the
The coagulation-sedimentation tank 40 and the dehydrator 50 are sequentially connected by a pipe, the discharge end of the dehydrator 50 faces the sludge hopper 61 of the kneader 60, and the raw water W of the raw water tank 10 reacts with the reaction tank 2
0, the coagulation-sedimentation tank 40, the dehydrator 50, and the kneading machine 60 in that order for processing, and the solidified sludge S is discharged from the kneading machine 60.

The raw water tank 10 has a raw water agitator 11, and a raw water supply pipe 12 is provided above the raw water tank 10.
Further, each outlet of the adjustment water supply pipe 13 is opened, and the overflow pipe 14 and the drain pipe 15 are connected to the upper wall portion and the lower wall portion of the raw water tank 10, respectively. The drain pipe 15 is provided with an electromagnetic opening / closing valve 15a. ing. Further, a raw water supply pump 16 is installed in the raw water tank 10, a raw water pipe 17 is connected to a discharge port of the raw water supply pump 16 and extends upward, and a discharge end thereof opens above the reaction tank 20. The raw water pipe 17 is provided with a flow meter 18.

The above-mentioned reaction tank 20 is composed of a first reaction tank 23 and a second reaction tank 24 which are adjacent to each other with a partition plate 21 in between. The first reaction tank 23 and the second reaction tank 24 are separated from each other by the partition plate 21. The lower opening 22 communicates with each other. The first reaction tank 23 is provided with a high-speed agitator 25, and the second reaction tank 24 is provided with a low-speed agitator 2.
6 are installed respectively. And the second reaction tank 24
A flock pipe 27 is connected to the upper part of the wall surface of the above, and a drain pipe 29 is connected to the bottom of each of the first reaction tank 23 and the second reaction tank 24 via an on-off valve 28A and an on-off valve 28B.

A flocculant supply device 3 above the reaction tank 20.
Reference numeral 0 denotes a flocculant tank 31 for accommodating a powdery flocculant F made of a carbonate aluminate salt material, and a screw-type fixed amount extruder 32 connected to the lower end thereof, and the discharge port of the extruder 32. An opening 33 opens downward above the first reaction tank 23 and at a height that does not contact the liquid surface of the first reaction tank 23. An electric vibrator 34 is attached to the conical portion below the coagulant tank 31 to prevent the coagulant F from forming a bridge.

The coagulating sedimentation tank 40 installed at the lower right of the reaction tank 20 has a conical bottom and has a rake 41 on its inner surface and a center well 42 above it. The center well 42 is connected to the second reaction tank 24 at one end thereof with a flock pipe 2
The other end of 7 is connected. A ring-shaped overflow gutter 43 is provided along the inner surface of the upper part of the coagulation-sedimentation tank 40, and a treated water collecting port 44 communicating with the ring-shaped gutter 43 is provided on the outer surface of the upper part of the coagulation-sedimentation tank 40. The treated water Ws is sent to a treated water tank (not shown) by the treated water pipe 45 connected to the bottom surface of the water collecting port 44.
On the other hand, a drainage pipe 46 and a sludge pipe 47 are connected to the lower end of the coagulating sedimentation tank 40, a drainage electromagnetic valve 46a is provided in the drainage pipe 46, and a sludge pipe 47 is provided.
Solenoid valve 47a for sludge and pump 48 for sludge
Are installed respectively.

The dehydrator 50 located to the right of the coagulating sedimentation tank 40 is a non-woven fabric endless belt 5 that rotates clockwise.
1 and a water collecting tank 52 provided therebelow, and the sludge pipe 47 is provided above the left end of the endless belt 51.
Of the sludge Sa continuously discharged from the pipe 47 is dropped onto the endless belt 51, and the sludge Sa is continuously dehydrated by its own weight as the endless belt 51 rotates. It is to be carried to the right and supplied to the kneader 60 through the chute 53 with a scraper at the right end, and the water discharged from the sludge Sa is collected in the water collecting tank 52 and is fed to the raw water tank 10 or the reaction tank 20 by the drain pipe 54. Will be returned. The dehydrator 50 includes an endless belt 51.
Backwashing device (not shown) is attached.

A kneader 60 located at the lower right of the dehydrator 50
Has a sludge hopper 61 at one end and an opening for discharging the solidified sludge S at the other end, and a discharge end of the chute 53 extends above the sludge hopper 61. A solidifying agent tank 70 is provided above the sludge hopper 61.
A rotary feeder 71 for discharging the powdery solidifying agent H mainly composed of coal ash or crushed stone powder downward at a predetermined speed is provided at the lower end of, and its discharge port is directed to the sludge hopper 61. ing. The solidifying agent tank 70
An electric vibrator 72 for preventing the formation of a bridge is attached to the lower part of the.

In the above structure, the raw water supply pipe 12 feeds the raw water W to the raw water tank 10 and the adjustment water pipe 13 sends an appropriate amount of adjustment water to fill the raw water tank 10 with the raw water W and the adjustment water. Solenoid on-off valve 15
a is closed, the raw water agitator 11 and the raw water supply pump 16
Is driven, the raw water W adjusted in the raw water tank 10 is supplied to the reaction tank 20 through the raw water pipe 17, and the reaction tank 2
After being filled with 0, it is sent to the flocculation-precipitation tank 40 by the head difference between the flocculation-precipitation tank 40 and the flocculation-precipitation tank 40. And the first in the meantime
In the reaction tank 23, pin flocs are formed by high-speed agitation, and in the subsequent second reaction tank 24, the above-mentioned pin flocs grow into large flocs, and the floc-containing water containing the growing flocs is located at the center of the coagulating sedimentation tank 40. It flows into the coagulating sedimentation tank 40 through the center well 42.

When the floc-containing water flows into the coagulation-sedimentation tank 40 through the center well 42, the downward flow is strengthened immediately below the center well 42, so that the floc precipitation is accelerated, and the floc content is small accordingly. When the treated water rises at a slow speed outside the center well 42 and the liquid level reaches the height of the ring-shaped gutter 43, the treated water Ws having a greatly reduced floc content overflows to the ring-shaped gutter 43. Inflow, treated water collecting port 44 and treated water pipe 4
It is sent to a treated water tank (not shown) via 5. On the other hand, the flocs settle on the conical surface at the bottom of the flocculation settling tank 40 to form sludge, which is scraped off by the rotation of the rake 41 and stored at the lower end of the conical portion.

When the sludge solenoid valve 47a is opened (the drainage solenoid valve 46a below the flocculation sedimentation tank 40 is closed) and the sludge pump 48 is driven when the overflow starts, the flocculation is conducted. The sludge Sa accumulated at the lower end of the settling tank 40 is discharged on the endless belt 51 of the dehydrator 50 via the sludge pipe 47 to be dehydrated, and then sent to the sludge hopper 61 of the kneader 60.
In synchronism with this, the rotary feeder 71 of the solidifying agent tank 70 located above is driven, and the powdery solidifying agent H is dropped onto the sludge hopper 61 at a predetermined speed. Then, the above sludge Sa and the solidifying agent H are kneaded by the kneading machine 60, and at that time, the water in the sludge Sa is absorbed by the solidifying agent H to solidify the sludge Sa, and the clay-like solidified sludge S is discharged. To be done.

Using the test apparatus having the above structure, red water containing suspended matter such as red soil was treated. That is, red water having a concentration of 5% is used as the raw water W, the raw water tank 10 is filled with the raw water W, and the concentration is adjusted to 3% with tap water.
^It is supplied to the first reaction tank 23 at a rate of ³ / min, and the coagulant F of a carbonate aluminate salt material is supplied to the first reaction tank 23 from the coagulant supply device 30 (manufactured by Samsung Chemical Joint Stock Company, trade name "POK").
-S ") is supplied at a rate of 300 g per 1 m ³ of raw water,
The reaction is carried out in order in the first reaction tank 23 and the second reaction tank 24,
Then, the sludge (water content 65%) is continuously taken out to the coagulation sedimentation tank 40, the water content is adjusted to 50% by the dehydrator 50, and the sludge is sent to the kneader 60.
From the solidifying agent supply device 70, a solidifying agent H containing fly ash as a main component (manufactured by Samsung Chemical Joint Stock Company, product number “No. 1
2 ") was supplied at a rate of 300 kg per 1 m ³ of the sludge after dehydration to obtain a solidified sludge S harder than clay. The impurities contained in the treated water taken out from the upper part of the coagulating sedimentation tank 40 were mainly inorganic ultrafine particles, and the amount thereof was 30 g per 1 m ³ of treated water.

In the above embodiment, the raw water tank 10 can be omitted, and the raw water supply pump 16 can be immersed in a river, a lake or the sea, and the raw water of the river or the like can be sent to the reaction tank as it is.
Further, the flocculant supply device 30 of the above-mentioned embodiment is one in which the screw type constant-rate extruder 32 is connected to the lower end of the flocculant tank 31, but if the flocculant in the device is not splashed with water. Of course, instead of the above-mentioned fixed quantity extruder 32, other fixed quantity discharge means such as an aspirator can be connected. Further, the reaction tank 20 of the above-mentioned embodiment is the high-speed stirrer 2
5 is composed of the first reaction tank 23 having 5 and the second reaction tank 24 having the low speed stirrer 26. Since the coagulant used in the present invention has a fast reaction, the raw water W and the coagulant F are rapidly stirred. Any means can be adopted as long as it is possible, for example, a plurality of baffle plates are provided in a labyrinth shape on the inner surface of a pipe or grooved water channel, and stirring is caused by collision with the baffle plate. But it's okay. Also, dehydrator 50
Can be of any type as long as it continuously dewaters the sludge.

[0023]

According to the invention described in claim 1, the raw water and the flocculant are reacted while flowing the raw water in one direction, the flocs generated are coagulated and precipitated, and the sludge generated by the precipitation is dehydrated and solidified. A method of treating muddy water using a powdered carbonate aluminate-based salt material as the coagulant, and using a powdered sludge solidifying agent mainly composed of coal ash or crushed stone powder for solidification of sludge Since it is a method, turbid water of fresh water or seawater can be continuously treated to efficiently produce solidified sludge, and the obtained solidified sludge is
It has excellent water resistance and does not dissolve again. Further, since no pH adjusting agent is used and only one type of powdered coagulating agent is used, a dissolution tank for each of the inorganic coagulating agent, the PH adjusting agent and the polymer coagulating agent, which has been required so far, is used. Also, a storage tank is not required, and the entire device can be downsized.

The invention as set forth in claim 2 is a powdery flocculant containing a carbonate aluminate salt material in the upper part of the reaction vessel, in which a reaction tank, a flocculation-precipitation tank, a dehydrator and a kneader are connected in this order. the provided coagulant supply equipment for dropping at a predetermined rate to the reactor, predetermined powdery sludge for solidifying agent composed mainly of coal ash and crushed stone dust sludge hopper above the kneader Since it is provided with a solidifying agent supply device for supplying to the sludge hopper at a speed of
The claim 1 is Ru can <br/> used in the practice of the invention described in. That is , by supplying arbitrary raw water to the reaction tank at a predetermined rate, the raw water is continuously processed to quickly generate flocs in the reaction tank, and the treated water is taken out from the upper part of the coagulation sedimentation tank. The sludge is taken out from the bottom, dehydrated, sent to a kneader, and kneaded with a solidifying agent to obtain clay-like solidified sludge.

[Brief description of drawings]

FIG. 1 is a process explanatory diagram of an example.

[Explanation of symbols]

W: raw water, Ws: treated water, Sa: sludge before solidification,
S: Solidified sludge, H: Powdered solidifying agent, F: Powdered flocculant, 10: Raw water tank, 11: Raw water agitator, 16: Raw water supply pump, 17: Raw water pipe, 20: Reaction tank, 21: Partition plate, 22: lower opening, 23: first reaction tank, 24: second
Reaction tank, 25: high speed agitator, 26: low speed agitator, 30:
Flocculant supply device, 31: Flocculant tank, 32: Fixed amount extruder, 34: Electric vibrator, 40: Flocculation sedimentation tank, 4
1: rake, 42: center well, 43: overflow gutter, 44: treated water collecting port, 50: dehydrator, 51:
Nonwoven fabric endless belt, 60: kneader, 61: sludge hopper, 70: solidifying agent tank, 71: rotary feeder, 72: electric vibrator.

Claims (2)

[Claims] 1. The raw water supplied to the reaction tank must not flow in one direction.
If the raw water in the reaction tank is above the coagulant tank above the reaction tank,
Tokoro powdered carbonate aluminate salt material as al coagulant
It is dropped at a constant speed and stirred to cause a flocculation reaction, and the resulting floc-containing water is continuously sent to a flocculation settling tank, where flakes are settled at the bottom of the flocculation settling tank. The supernatant liquid is taken out as treated water, while the sludge containing a large amount of flakes is continuously taken out from the bottom of the coagulating sedimentation tank, sent to the kneader while dehydrating and adjusting the water content, and the coal ash and crushed stone are mixed in this kneader. A method for treating turbid water, which comprises kneading with a powdery solidifying agent for sludge containing powder as a main component to solidify the sludge to produce solidified sludge. 2. A reaction tank capable of stirring with a stirrer while flowing the supplied raw water in one direction, and a powdery flocculant containing a carbonate aluminate-based salt material, which is installed above the reaction tank. A flocculant supply device for dropping the powdery flocculant into the lower reaction tank at a predetermined speed, a center well in the center, and a rake along the conical bottom surface are provided. the flocs containing water delivered through the use pipe disposed below the reaction vessel so as to flow into the center well, the reactor
And the agglutination settling tank connected by the flock pipe, connected with a sludge pipe at the bottom of the agglutination settling tank, the upper
And dehydrator for dehydrating the sludge sent from the bottom of the serial coagulating sedimentation tank continuously through the sludge pipe,
A kneader equipped with a sludge hopper for continuously receiving dewatered sludge discharged from this dewatering machine, and a powdery sludge mainly composed of coal ash or crushed stone powder installed above the sludge hopper. An apparatus for treating turbid water, comprising: a solidifying agent supplying device capable of containing the solidifying agent and supplying the sludge solidifying agent to the sludge hopper at a predetermined speed.