JP3320851B2 - Coagulation concentration device and coagulation concentration method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a floc having a high solid-liquid separation performance without using a flocculant after a dilute contaminant is maintained at a concentration sufficient to form a floc. The present invention relates to an apparatus and method for coagulating and condensing sludge.

[0002]

2. Description of the Related Art In coagulating a dilute contaminated liquid, a reaction chamber for high-speed stirring is provided in order to enhance the effect of collision between fine particles to be coagulated by adding an inorganic coagulant, and a floc to be formed with a small floc is formed. When the separation performance is low, a method has been adopted in which a polymer flocculant is further added to form a huge floc by bridging the polymer flocculant between the fine flocs and then separated in a precipitation tank. The flocculent sludge of the fine floc formed by adding the flocculant of this method does not re-agglomerate even if it is repeatedly circulated and added to the dilute contaminated liquid.

[0003] The present inventor has previously described an aggregating apparatus and an aggregating apparatus for aggregating and separating fine particles [microorganisms (activated sludge), algae, minerals, plankton, etc.] from treated water containing fine particles such as brewery waste liquid, culture growth liquid, and dredging. Developed a method ( Tokuhei 7-
No. 16563 ). In the aggregation device provided vertically mixing tube into a vertical solid-liquid separation chamber of the agglomeration apparatus, a much wider space than the space mixed-tract until flocs reach the bottom of the solid-liquid separation chamber Therefore , it is difficult to form a giant floc by colliding the unagglomerated fine particles existing in the contaminated liquid with the flocs already generated. In particular, when a dilute contaminant is used, the floc formed by the fine particles in the vertical mixing tube is small, and the coagulated sludge discharged from the mixing tube is mixed with non-coagulated fine particles and small flocs with low sedimentation performance. Separation performance has been lowered.

[0004]

The object of the invention is to you'll solve the present invention is especially fair 7-1
The present invention aims to enhance the solid-liquid separation performance by promoting the concentration of flocs generated by the flocculation apparatus and the flocculation method described in No. 6563 and the drawings. Even if the mixture is supplied to a vertically provided mixing tube while maintaining the concentration sufficient to form flocs, the mixing tube having no bottom [(the cross-sectional area of the solid-liquid separation chamber is 10% of the total cross-sectional area of the mixing tube even if there is a bottom. (The distance from the mixing tube discharge port to the bottom of the tank is at least 5 times the diameter of the mixing tube), and is hereinafter referred to as a bottomless mixing tube. In [1], since there is little collision in the mixing tube, unagglomerated fine particles are mixed with the floc at the mixing tube discharge port, and the solid-liquid separation performance is low. An object of the present invention is to provide a processing system having a high solid-liquid separation performance and a high filtering performance and a low processing cost by providing a floc forming tank at a discharge port of a mixing tube for enhancing the collision between flocs and unagglomerated fine particles.

[0005]

Means for Solving the Problems The present inventor has disclosed Japanese Patent Publication No. 7-1.
No. 6,563 , a floc forming tank is provided in the solid-liquid separation chamber of the flocculating apparatus, and a flocculating and concentrating apparatus having a structure in which the discharge port of the mixing pipe is provided in the floc forming tank,
The floc was flocculated in a short time and concentrated sludge was obtained. The flocculation apparatus used in the practice of the present invention supplies a pollutant having a pollutant concentration sufficient for flocculation, provides a dispersion chamber for dispersing and a mixing pipe opened in the dispersion chamber, inserts an injection pipe into the mixing pipe, and performs injection. An injection liquid having an electrolyte concentration lower than the electrolyte concentration of the contaminated liquid flowing through the mixing tube from the tube discharge port is supplied downstream along the flow in the mixing tube. The flow of the injection liquid and the flow of the contaminated liquid flowing into the mixing tube are laminar (10 <
Re <10 ⁵ ) Upon contact, a difference is generated in the electrolyte concentration on the particle surface between the particles in contact with the injection liquid and the particles not in contact with the injection liquid between the fine particles at the interface, resulting in a difference in the potential based on the electrolyte concentration. . Intense collision is repeated even between fine particles of 1 to 5 × 10 ⁻⁴ mm which are difficult to collide with each other, so
The mixed liquid having formed a huge floc of about 1 mm is sent to a solid-liquid separation chamber, where the floc is separated.

The flocculating and concentrating apparatus of the present invention has a structure in which a floc forming tank is provided in the solid-liquid separation chamber of the above flocculating apparatus, and the discharge port of the mixing pipe is opened so as to be located in the floc forming tank. The present invention is characterized in that flocculants that have aggregated are concentrated in a solid-liquid separation chamber and used as a floc concentration chamber that forms a solid-liquid separation chamber.

[0007] be described with reference to diagram the structure of the aggregation concentrator of the present invention shown in FIG. 1, the agglomerator comprising a dispersion chamber 18 and the solid-liquid separation chamber 10 Prefecture, the dispersion chamber 18 and the solid-liquid separation chamber 10 Is connected to the dispersion chamber at one end by a mixing pipe 17 having the other end opened to the solid-liquid separation chamber. The number of mixing tubes is 1
Or three (two in FIG. 1 and three in FIG. 3 ). An injection pipe 19 for injecting the injection liquid is provided in the mixing pipe. The injection tube has been kicked one set in each mixing tube. (In FIG. 1, one injection pipe is provided for each mixing pipe.) The discharge port of the injection pipe (injected liquid) faces the downstream of the contaminated liquid flowing in the mixing pipe. A floc forming tank 9 is provided in a solid-liquid separation chamber 10 of the apparatus, and an opening (discharge port) 8 of the mixing tube is provided so as to be located in the floc forming tank.

[0008] Incidentally, Ru Tei provided outlet for taking out the flocs coagulated concentrated in the chamber bottom of the solid-liquid separation chamber 10 (sludge).

The floc forming tank 7 provided in the coagulating and concentrating apparatus of the present invention has a cross-sectional area that increases from the tank bottom to the top, and is open at the top of the tank. The opening edge is substantially horizontal, and constitutes an overflow weir 9 of a giant floc generated in the floc forming tank.

The shape of the floc forming tank 7 is frustoconical or
Is a truncated pyramid and is open with its larger horizontal cross-sectional area facing upwards, and the smaller horizontal cross-sectional area has a bottom, as can be seen from reference numeral 20 in FIG.

In the coagulation and concentration apparatus of the present invention, the mixing tube 1
The discharge port 8 of 7 has a structure opened in the floc forming tank. In FIG. 4, the position of the discharge port of the mixing tube in the floc forming tank is 1 to 10 times the diameter of the mixing tube from the bottom of the floc forming tank. The position of the mixing pipe discharge port is 1 meter of the mixing pipe diameter from the bottom of the floc forming tank.
If the distance is more than 0 times, unagglomerated fine particles that did not form flocs in the mixing tube do not decrease and the collision effect seems to be small. The cross-sectional area of the bottom of the impingement mixing section 20 in the floc forming tank has an area of 1 to 10 times the total area of the mixing pipe discharge port, and is not coagulated from the bottom to a position (distance) about 10 times the diameter of the mixing pipe. Where fine particles form small flocs (collision mixing section 2
0), the coagulated liquid (mixed liquid of the contaminated liquid and the injection liquid) discharged from the discharge port of the mixing tube collides with the bottom of the collision mixing section 20, and the fine particles, small flocs, and medium flocs mutually interact. The flow becomes an upward flow while violently colliding, and reaches the fluidized bed portion 21 at the center of the tank.

Above the impingement mixing section 20 is a fluidized bed section 21 of a floc forming tank, which expands along the axis of the mixing pipe as the horizontal sectional area of the floc forming tank increases.
1 is in the range of 5 to 20 times the diameter of the mixing tube from the bottom of the tank. In the fluidized bed portion 21, a heavy collision is repeated between medium and small flocs to form large flocs. It is difficult to form a large floc unless the fine particles released from the discharge port of the mixing tube form a small floc up to this region.

The cross-sectional area of the uppermost part of the floc forming tank is as large as 15 to 150 times the total area of the discharge port of the mixing tube, the flow velocity is reduced, and the winding of fine particles is completely eliminated. Giant flocs are formed while in contact, and flocculated sludge flows out of the overflow weir in the floc forming tank. If a floc forming tank is installed, 10 kg / m in activated sludge
^{Even if} a liquid having a high concentration of about ³ is treated, 25 Kg / m ^{3 of} highly concentrated sludge which is close to the ultimate concentration of activated sludge can be obtained.

In the coagulating and concentrating apparatus of the present invention, the inclined plate 2 is located at a predetermined distance in parallel with the side wall of the floc forming tank 7.
3, flocculated sludge overflowing from the overflow weir 9 of the floc forming tank is slid down between the side wall of the floc forming tank and the inclined plate to be deposited on the bottom of the solid-liquid separation chamber 10. The distance between the side wall of the floc forming tank and the inclined plate is preferably kept at 5 to 20 cm. The coagulated sludge is mainly slid down on the inclined plate and transferred to the coagulated concentrated sludge at the bottom of the solid-liquid separation chamber. In the solid-liquid separation chamber of the apparatus of the present invention, concentrated sludge can be obtained in a very short time without disturbance due to the sludge discharged from the discharge port of the mixing tube.

[0015] The present invention is a dispersion chamber 18 and the solid-liquid separation chamber 10 as shown in FIG. 1 has been described concatenated vertical apparatus vertically by mixing tube 17 Kokoku No. 7-16563 <br/> the Even in a horizontal agglomeration device in which the mixing pipe is horizontal or inclined as described in, after the mixing pipe and the injection pipe take the distance from the injection pipe discharge port to the mixing pipe discharge port as shown in FIG.
Ambassador horizontal from the vertical mixing tube against a horizontal surface 30
The object of the present invention can be achieved by bending in an infinite direction and opening the discharge port to the collision mixing section 20 in the floc forming tank.

The flock forming tank having a truncated right conical shape in FIG.
Large circular diameter (R) opens up, small circular diameter (r)
Is a tank bottom, and the upper opening edge and the bottom edge of the tank bottom are surrounded by side walls. The inclined plate 23 of the floc forming tank is Rcm +
(. 5 to 20 cm) in diameter is opened up of, rcm + (5 ~
20 cm) outside of the side wall of the truncated right cone, which also opens downward. The uppermost edge (overflow weir 9) of the side wall of the floc forming tank is kept horizontal, and the uppermost edge of the inclined plate 23 is higher than that of the floc forming tank. FIG. 3 shows a pyramid-shaped flock forming tank in which the truncated open pyramid and the bottom of the trough form a square. A truncated pyramid is a container in which a large square is open at the top, a small square is the tank bottom, and the upper opening edge and the bottom edge of the tank bottom are surrounded by side walls. Tilting the swash floc formation tank plate 23 but on the outside of the side wall of the truncated pyramid which is open vertically at intervals of pyramidal side walls and 5 to 50 cm. The top edge of the side wall of the flock forming tank is kept horizontal, and the top edge of the inclined plate 23 is higher than that of the flock forming tank .

In the coagulation and concentration method of the present invention, the flow rate of the contaminated liquid in the mixing tube is maintained at 10 <while maintaining the concentration at which the fine particles can collide with each other.
The Re <10 ^5, the flow rate of the injection tube of the infusate 5 <Re <
Maintained at 10 ^4, after completing the agglomeration by contacting the two liquids in the mixing tube, using the aggregation concentrator having an opening to expand upward from the tank bottom of the flocculation tank provided in the solid-liquid separation chamber Then, the non-agglomerated fine particles discharged from the mixing tube discharge port and the floc are forcibly collided in the collision mixing section in the floc forming tank, and all the non-agglomerated fine particles are floc larger than the small floc. Intense collisions are repeated in the upper fluidized bed portion, and the flocs become large flocs. In the uppermost moving bed portion of the floc forming tank, large flocs are formed by gentle collision between the large flocs. The giant floc overflows from the overflow weir and slides down the inclined plate and descends to the coagulated and concentrated sludge layer in the solid-liquid separation chamber .

A dilute contaminant is a liquid having a low concentration of contaminants, a small floc diameter, and low solid-liquid separation performance. If the concentration of the pollutant is low, improvement in solid-liquid separation performance cannot be expected even if a floc forming tank is provided. The amount of the fine particles to be added may be small if the specific gravity of the fine particles is slightly larger than 1 and the floc forming ability is high. SS concentration of dilute polluted liquid when using as a for post SS removal water at 50ppm or less,
Diatomaceous earth 1000p as fine particles with low solute content
When pm or more is added, the diameter of the floc increases and the solid-liquid separation performance is good .

The flocculated and concentrated sludge having a large floc discharged from the stirring / mixing tank or the stirring / mixing tube and the solid-liquid separation device for mixing the fine particles containing a small amount of solute added to the diluted sludge is returned to the diluted sludge. There is a need for a circulation system that includes a circulation pump that circulates. There is a discharge system that discharges excess coagulated sludge by a circulation pump. Stirred mixing vessel also adding large aggregates concentrated sludge flocs in a dilute polluted liquid
As the stirring and mixing tube, use is made of the stirring and mixing tank or the stirring and mixing tube previously used for mixing the fine particles having a small solute content.

[0020]

[Embodiment 1] The coagulation and concentration apparatus of the present invention shown in FIG. 1 was used.
An example of processing a dilute polluted liquid S S concentration 8~15ppm Te. Was continuously fed to the mixing vessel 5 is stirred with diatomaceous earth 6 and water 2 in advance by the primary mixing tank 4 the liquid slurry in a slurry pump 3, the resulting polluted liquid in a dilute polluted liquid 1 m ³ using a feed pump 15 It was added diatomaceous earth 6Kg percentage. 0.25 m ³ / hr of the mixture is supplied to the dispersion chamber 18 . The mixed liquid of the contaminated liquid and the injection liquid is discharged to the floc forming tank from the discharge port 8 of the mixing pipe opened to the collision mixing section 20 in the floc forming tank 7 of the coagulating and concentrating apparatus of FIG. The small flocs agglomerated in the pipe, or the non-agglomerated particles and the small flocs collide violently in the collision mixing section, and the unagglomerated fine particles are completely eliminated in the solid-liquid separation chamber 10. The small flocks form medium and large flocks. Further, a giant floc is formed in the upper moving layer portion 22 of the floc forming tank, and the giant floc slides down the inclined plate 23 from the overflow weir 9 of the floc forming tank and descends into the solid-liquid separation chamber 10 in the coagulated concentrated sludge layer. . Table 1 shows the supernatant liquid 11 and the value of the SS concentration at the outlet of the circulation pump 12 when treated with this apparatus.
It was shown to. The supernatant liquid is discharged from the upper part of the solid-liquid separation chamber (concentration tank). You. A part of the sludge is withdrawn from the circulation pump 12 and sent to the filter 13 to dispose of the filter cake. On the other hand, as a comparative example, the SS concentration at the outlet of the circulating pump 12 of the supernatant liquid 11 and the solid-liquid separation chamber 10 when the same contaminated liquid was treated using the apparatus of FIG. It was measured. The results are shown in Table 1.

[0021]

[Table 1] Aggregation concentrator of this result or et obvious the present invention having the flocculation tank as the aggregation concentration function of the fine particles in the polluted liquid as compared with the conventional coagulation apparatus that is better is clear.

[0022]

The floc formation tank of the flocculation and concentration apparatus according to the present invention forcibly collides the non-condensed fine particles with the small flocs, so that the floc becomes huge and the horizontal type in which the mixing pipe is inclined, the floc formation tank. Is provided, concentrated sludge can be obtained in a short time at a shallow water depth. In addition, the solid-liquid separation chamber can be downsized, and the quality of the supernatant liquid is SS
There is almost no homogenization, and maintenance is easy.

[Brief description of the drawings]

FIG. 1 is an explanatory view of providing a floc forming tank in a solid-liquid separation chamber to coagulate and concentrate a contaminated liquid.

FIG. 2 is an explanatory view showing a frustoconical flock forming tank.

FIG. 3 is an explanatory view showing a truncated pyramid type floc forming tank.

FIG. 4 is an explanatory diagram showing a relationship between a floc forming tank and a mixing pipe of the aggregating apparatus (horizontal type) .

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Dilute contaminated liquid 2 Water 3 Slurry pump 4 Primary mixing tank 5 Stirring mixing tank 6 Diatomaceous earth 7 Floc forming tank 8 Mixing tube discharge port 9 Overflow weir 10 Solid-liquid separation chamber 11 Supernatant liquid 12 Circulation pump 13 Filtration machine 14 Coagulation concentration Sludge 15 Contamination liquid supply pump 16 Injection liquid 17 Mixing pipe 18 Dispersion chamber 19 Injection pipe 20 Collision mixing section 21 Fluidized bed section 22 Moving bed section 23 Inclined plate

Claims (6)

(57) [Claims] [Claim 1, further comprising a dispersion chamber 18 and the solid-liquid separation chamber 10 for polluted liquid storing the disperse containing fine particles, between the dispersion chamber and the solid-liquid separation chamber, one end opened to the dispersion chamber And one to three mixing pipes 17 each having the other end opened as a discharge port in the solid-liquid separation chamber.
Are connected by, in the mixing tube, respectively toward the injection pipe 19 for injecting a single injection liquid downstream of the polluted liquid flowing through the discharge port mixing tube of the infusion fluid is open structure And flocculated fine particles are stored at the bottom of the solid-liquid separation chamber 10, and the fine particles in the contaminated water having a structure having an outlet for the floc are aggregated as flocs to form water. The flocculation device has a structure in which a floc forming tank 7 is provided in the solid-liquid separation chamber 10 and the discharge port 8 of the mixing pipe 17 is opened so as to be located in the floc forming tank 7. A flocculating and concentrating apparatus that concentrates the floc thus obtained in a solid-liquid separation chamber and uses the solid-liquid separation chamber as a concentration chamber. 2. The shape of the floc forming tank 7 is such that its cross-sectional area increases from the tank bottom to the top and is open at the top of the tank, the opening edge is horizontal and the overflow weir 9 is formed. The huge floc generated in the tank overflows and the solid-liquid separation chamber 10
The coagulating and concentrating device according to claim 1, wherein the coagulating and concentrating device is deposited on the bottom of the chamber. The shape of claim 3 wherein said flocculation tank 7, of frusto-conical or truncated pyramidal, have any one shape,
The coagulating and concentrating device according to claim 1 or 2, wherein the opening having the larger horizontal cross-sectional area is open, and the smaller horizontal cross-sectional area is bottomed. 4. An inclined plate is provided at a predetermined distance in parallel with the side wall of the floc forming tank 7, and coagulated sludge overflowing from the overflow weir of the floc forming tank is interposed between the side wall of the floc forming tank and the inclined plate. any serial mounting of <br/> aggregation concentrator of claims 1 to 3 so as to deposit on the chamber floor of the solid-liquid separation chamber 10 is downhill. 5. The discharge port of the mixing pipe 17 is a floc forming tank 7.
Claim 1 乃 to the impingement mixing portion 20 of the inner having an open structure
Any serial mounting of aggregation concentrator of Itaru 4. 6. Using the aggregation concentrator of claim 1 Symbol placement,
In separating fine particles and water from the contaminated liquid containing fine particles, the flow of the contaminated liquid in the mixing tube is 10 <Re <1.
0 ⁵ , the flow of the injection liquid discharged from the injection pipe is 5 <Re <
10 ⁴ with the flow of the polluted liquid retention to mixing tube ranges flowing in contact with the flow of the infusate, the interface to form, the interface in to form a floc, then flocculation from the discharge port of the mixing tube so The fine particles, which are discharged into the tank and form giant flocs in the floc forming tank, overflow the generated giant flocs from the floc forming tank, and deposit on the bottom of the solid-liquid separation chamber. A coagulation concentration method of forming flocs of fine particles from a contaminated liquid containing water and separating water from water.