KR101442937B1 - Method for starting high-density-sludge generating water treatment device - Google Patents

Abstract

The present invention provides a method for operating a high-density sludge generation type water treatment apparatus capable of shortening the operation time of a high-density sludge generation type water treatment apparatus. The method includes the steps of: repeating a series of steps to generate high- density sludge; And a high-density sludge generation step of generating a high-density sludge from the low-density sludge in the apparatus by repeating the series of steps, wherein in the high-density sludge generation step, (Sludge volume ratio), which is the ratio of the volume of the area (separated sludge area) below the sludge interface in the sedimentation tank to the volume of the area of the sludge-collecting sludge area (tank inner liquid area), is 30 vol% or less.

Description

METHOD FOR STARTING HIGH-DENSITY-SLUDGE GENERATING WATER TREATMENT DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a method for operating a high-density sludge generation type water treatment apparatus.

In recent years, high density sludge (HDS (High Density Solids) sludge) generated by a reaction of metal hydroxide precipitation by a neutralization reaction has attracted attention. The high-density sludge is excellent in sedimentation property and dewatering property, and is thought to be useful for volume reduction of sludge. High-density sludge is generally produced in the following manner. That is, raw water (raw water) containing inorganic ions such as aluminum ions is sequentially treated in the insolubilization treatment tank and coagulation sedimentation tank, and the separated sludge obtained in the coagulation sedimentation tank is supplied to the sludge reforming tank. Then, in the sludge reforming tank, alkali is adsorbed to the separated sludge to produce adsorbed sludge, and then the adsorbed sludge and the inorganic ions in the inorganic wastewater are brought into contact with each other to form an insoluble matter on the surface of the adsorbed sludge. In this manner, high-density sludge is produced during the treatment of the raw water.

In order to produce such a high-density sludge, a water treatment apparatus capable of generating a high-density sludge (hereinafter referred to as a "high-density sludge generation water treatment apparatus") is installed, and an existing water treatment apparatus including a flocculation- , It is also conceivable to switch to a high-density sludge generation type water treatment apparatus by modification. At this time, when the supply of the raw water to the high-density sludge generation type water treatment apparatus is started, and particularly when the existing water treatment apparatus is switched to the high density sludge generation type water treatment apparatus, since the factory for discharging the raw water is in a full- The inorganic ion concentration is often high. Therefore, it is very important to increase the concentration of the high-density sludge in a short period of time in the high-density sludge generation type water treatment apparatus, that is, to operate the high-density sludge generation type water treatment apparatus in a short period of time.

As a method for increasing the concentration of high-density sludge in a high-density sludge-generation-type water treatment apparatus in a short period of time, there is known one disclosed in Patent Document 1 below. Patent Document 1 discloses a method of adding a compound containing an inorganic ion source and an insolubilizing agent to a reaction tank before raw water is supplied to a reaction tank (corresponding to an insolubilizing treatment tank), accumulating sludge in a solid- , It is proposed that the water treatment apparatus is operated in a short period of time by supplying raw water to the reaction tank after sufficiently securing the sludge which becomes a seed crystal.

Japanese Laid-Open Patent Publication No. 2006-272121

However, the method described in Patent Document 1 still has room for improvement in terms of shortening the operation period of the high-density sludge generation type water treatment apparatus.

It is an object of the present invention to provide a method for operating a high-density sludge generation type water treatment apparatus capable of short-time operation of a high-density sludge generation type water treatment apparatus.

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies to solve the above problems. First, in the operation method of Patent Document 1, since the separated sludge in the solid-liquid separating tank is accumulated without returning, the amount of sludge in the tank is very large. Therefore, in the initial stage of the operation, since the modification of the dense sludge of the aggregated block existing excessively in the solid-liquid separation tank is dispersed, the ratio of the high-density sludge circulating in the system hardly becomes large and the concentration of the high- The present inventors thought that it would not be possible to increase it. The inventors of the present invention have conducted extensive research and have found out that the above problems can be solved by controlling the volume ratio of the separated sludge area in the tank of the solid-liquid separation tank to be a predetermined value or less at the initial stage of operation, .

That is, the present invention provides a process for producing a water-insoluble material, comprising: an insolubilizing treatment tank for insolubilizing inorganic ions in introduced inorganic ion-containing wastewater; a sedimentation tank for precipitating and separating effluent water introduced from the insolubilizing treatment tank into treated sludge and separated sludge; A separation sludge supply line connected to the sludge feed line and connected to the separation sludge supply line, and a counter for forming the inorganic ion and the insoluble matter on the surface of the separated sludge, And a counter ion-containing substance supply means for supplying the counter ion-containing substance to the sludge reforming tank, wherein the counter ion-containing substance supply means comprises a counter ion-containing substance supply means for adsorbing the counterion- The inorganic ion-containing wastewater introduced into the insolubilizing treatment tank is supplied from the sludge reforming tank An insolubilizing step of bringing the inorganic ion in the inorganic ion-containing wastewater into contact with the adsorbing sludge and causing the inorganic ion in the inorganic ion-containing wastewater to react with the counter ion of the adsorbing sludge to insolubilize the effluent; A separation sludge supply step of supplying at least a part of the separated sludge discharged from the sedimentation tank to the sludge reforming tank via the separated sludge supply line; And an adsorbing sludge generating step of adsorbing the counterion-containing material on the surface of the separated sludge to produce an adsorbed sludge, thereby producing a high-density sludge and performing the present operation. In the high-density sludge generation type water treatment apparatus The high-density sludge generation type water treatment apparatus And a high-density sludge generation step of generating high-density sludge from the low-density sludge in the apparatus by repeating the series of steps, wherein during the high-density sludge generation step, the sedimentation tank (Sludge volume ratio), which is the ratio of the volume of the area (sludge separation area) below the sludge interface with respect to the volume of the area (tank inner liquid area) of the high density sludge This is a method of operating the generation type water treatment apparatus.

According to this method of operating the high-density sludge-generation water treatment apparatus, the inorganic ion-containing wastewater is introduced into the insolubilization treatment tank. On the other hand, when the counter ion-containing substance is supplied to the sludge reforming tank by the counter ion-containing substance supply means, the counterion-containing substance is adsorbed on the surface of the separated sludge to generate adsorbed sludge. And is supplied to the treatment tank. At this time, since the inorganic ion-containing wastewater is brought into contact with the adsorbing sludge in the insolubilizing treatment tank, inorganic ions in the inorganic ion-containing wastewater react with the counter ions of the adsorbing sludge to be insoluble. Then, the effluent water from the insolubilization treatment tank is introduced into the sedimentation tank, and separated by sedimentation with the separated sludge and treated water. Then, at least a part of the separated sludge is supplied to the reforming tank through the separated sludge supply line from the settling tank, and adsorbed sludge is generated in the sludge reforming tank as described above, and this adsorbed sludge is supplied from the sludge reforming tank to the insoluble treatment tank. By repeating the above-described series of steps in this way, high-density sludge is produced. The sludge volume ratio, which is the ratio of the volume of the separated sludge region to the volume of the crude inner fluid region, is controlled to be 30 vol% or less while the high-density sludge is produced and grown by repeating this series of steps. As a result, in the sedimentation tank, the ratio of the high-density sludge in the separated sludge can be prevented from being lowered, and it is possible to suppress the generation delay of the high-density sludge by the excessive amount of the aggregated block. Therefore, according to the method of operating the high-density sludge generation type water treatment apparatus of the present invention, high-density sludge can be sufficiently generated in a short period of time, and as a result, the concentration of high-density sludge can be increased in a short period of time. That is, the operation of the high-density sludge generation type water treatment apparatus can be performed in a short period of time. As a result, the main operation after the operation can be performed early.

In the above-mentioned operating method, it is preferable to control the sintered body ratio to be 4 to 30 vol%.

In this case, at the time of operating the high-density sludge generation type water treatment apparatus, high-density sludge can be sufficiently generated in a short period of time, and the concentration of high-density sludge can be increased in a shorter period of time. That is, the operation of the high-density sludge generation type water treatment apparatus can be performed in a shorter period of time.

Wherein the operation method further comprises a drainage introducing step of introducing the inorganic ion-containing drainage water into the insolubilization treatment vessel and a treatment water discharging step of discharging treatment water obtained by sedimentation separation in the sedimentation tank, This is particularly useful when ion-containing wastewater is plant wastewater.

This is because, when the supply of the factory drainage to the high-density sludge generation-type water treatment apparatus is started, the plant discharging the factory drainage is in a full-on state, and when the flow rate of the factory drainage or the concentration of the inorganic ion is high, The water quality of the treated water obtained by the separation tends to be deteriorated, so that it becomes more important to operate the high-density sludge-generation type water treatment apparatus in a short period of time.

The separated sludge having a sludge concentration C1 (g / l) of the sedimentation tank was taken out and placed in a measuring cylinder. After standing for 24 hours to precipitate and separate the sludge, the concentration ratio of the sludge was R, If the sludge concentration in the region is C2 (g / l), then C2 = C1 / R. Here, the concentration ratio R is a ratio calculated as the ratio of the capacity of the sludge region in the measuring cylinder (the capacity of the sludge region after standing for 24 hours / the capacity of the sludge region before standing for 24 hours). The high-density sludge in the present invention means that when the inorganic ion is Al ^{3 +} , Fe ^{2 +} , Fe ^{3 +} , Cr ^{2 +} , F ^- , PO ₄ ^{2 -} or SO ₄ ^{2 -} And when the inorganic ion is Cu ^{2 +} , Mn ^{2 +} , Ni ^{2 +} or Zn ^{2 +} , it indicates that sludge has a C ² of 50 g / ℓ or more. Also, the unit of the sludge concentration may be wt% instead of g / l. In this case, the high density sludge in the present invention means that when the inorganic ion is Al ^{3 +} , Fe ^{2 +} , Fe ^{3 +} , Cr ^{2 +} , F ^- , PO ₄ ^{2 -} or SO ₄ ^{2 -} %, And when the inorganic ion is Cu ^{2 +} , Mn ^{2 +} , Ni ^{2 +} or Zn ^{2 +} , the sludge has a C ^{2 content} of 5 wt% or more. The sludge which does not satisfy the above conditions is referred to as low-density sludge.

According to the method for operating the high-density sludge generation type water treatment apparatus of the present invention, the operation of the high-density sludge generation type water treatment apparatus can be performed in a short period of time.

1 is a flow chart showing an example of a high-density sludge generation type water treatment apparatus to be subjected to a method of operating the high-density sludge generation type water treatment apparatus according to the present invention.
2 is a schematic view showing an isolated sludge region and a crude oil solution region in a settling tank.
3 is a graph showing the relationship between the concentration of sludge and the number of elapsed days obtained in the execution of the moving method related to Example 4 and Comparative Example 1. Fig.
Fig. 4 is a graph showing the relationship between the concentration of sludge and the number of days elapsed from the sludge obtained in the running method according to Example 9 and Comparative Example 3. Fig.
FIG. 5 is a graph showing the relationship between the concentration of sludge and the number of days elapsed since the operation method related to Example 10 and Comparative Example 4 was carried out.
Fig. 6 is a graph showing the relationship between the concentration of sludge and the number of days elapsed in the operation method related to Example 11 and Comparative Example 5. Fig.
FIG. 7 is a graph showing the relationship between the concentration of sludge and the number of days elapsed since the operation method related to Example 12 and Comparative Example 6 was carried out.
8 is a graph showing the relationship between the concentration of sludge and the number of days elapsed since the operation method related to Example 13 and Comparative Example 7 was carried out.
FIG. 9 is a graph showing the relationship between the concentration of sludge and the number of days elapsed in the execution of the operating method related to Example 14 and Comparative Example 8. FIG.
10 is a graph showing the relationship between the concentration of sludge and the number of days elapsed since the operation method related to Example 15 and Comparative Example 9 was carried out.
FIG. 11 is a graph showing the relationship between the concentration of sludge and the number of days elapsed since the operation method related to Example 16 and Comparative Example 10 was carried out.
12 is a graph showing the relationship between the concentration of sludge and the number of days elapsed since the operation method related to Example 17 and Comparative Example 11 was carried out.

Hereinafter, the first and second embodiments of the present invention will be described in detail.

≪ First Embodiment >

First, a first embodiment of a method for operating a high-density sludge generation type water treatment apparatus according to the present invention will be described in detail.

First, prior to description of the operation method, a high-density sludge generation type water treatment apparatus for carrying out a method of operating the high-density sludge generation type water treatment apparatus according to the present invention will be described with reference to Fig. 1 is a flow chart showing an example of a high-density sludge generation type water treatment apparatus for carrying out a method of operating a high-density sludge generation type water treatment apparatus according to the present invention.

1, the high-density sludge generation type water treatment apparatus includes a first insolubilizing treatment tank 1, a second insolubilizing treatment tank 2, an aggregation treatment tank 3, a sedimentation tank 4, (5).

An introduction line L1 for introducing inorganic ion-containing waste water containing inorganic ions is connected to the first insolubilization treatment tank 1 and the first insolubilization treatment tank 1 and the second insoluble treatment tank 2 The second insolubilization treatment tank 2 and the flocculation treatment tank 3 are connected by an intermediate line L3 and the flocculation treatment tank 3 and the sedimentation tank 4 are connected by an intermediate line L2, Are connected by an intermediate line L4.

The settling tank 4 and the sludge reforming tank 5 are connected by a separated sludge supply line L5 for supplying the separated sludge 11 obtained in the settling tank 4 to the sludge reforming tank 5, 5 and the first insoluble treatment tank 1 are connected by an adsorbing sludge supply line L11 for supplying the adsorbed sludge obtained in the sludge reforming tank 5 to the first insolubilizing treatment tank 1.

A treated water discharge line L7 for discharging treated water is connected to the settling tank 4 and a sludge discharge line L5 for discharging the separated sludge 11 obtained from the settling tank 4 L6 are branched. The sludge supply line L5 is provided with a sludge supply pump P2, a flow meter 6 and a sludge concentration meter 7, and a sludge discharge line L6 is provided with a vane pump P1. Here, the sludge supply pump P2 and the sludge concentration meter 7 are electrically connected to each other. Based on the sludge concentration measured by the sludge densitometer 7, So that the supply amount of the separated sludge 11 can be controlled.

A pH adjuster supply tank 8 is connected to the first insoluble treatment tank 1 through a line L8 and a pH adjuster supply tank 8 is connected to the second insoluble treatment tank 2 via a line L9. 9 are connected to the flocculation tank 3, and the flocculation tank 10 is connected to the flocculation tank 3 through a line L10.

The sludge reforming tank 5 is capable of introducing the counter ion-containing substance containing the counter ion forming the inorganic ion and the insoluble matter via the line L12 provided with the valve V1. In the present embodiment, the valve V1 and the line L12 constitute the counter ion-containing substance supply means.

Next, a method of operating the high-density sludge generation type water treatment apparatus will be described. The operation method includes the present operation step and a moving step performed before that.

First, the operation process of the high-density sludge generation type water treatment apparatus will be described. In the present embodiment, the case where the high-density sludge generation type water treatment apparatus is newly established with the establishment of a factory for discharging inorganic ion-containing wastewater will be described as an example.

In the case where the high-density sludge-generation water treatment apparatus was newly established with the establishment of a factory for discharging inorganic ion-containing wastewater, the sludge concentration in the sedimentation tank 4 was 0 g / l at the start of the moving process . For this reason, the moving process includes a sludge accumulating process performed after the start of operation and a dense sludge generating process for generating high-density sludge performed thereafter.

First, the sludge accumulation process will be described. In the sludge accumulation process, the inorganic ion-containing drainage (for example, plant drainage) is introduced into the first insolubilization treatment tank 1 via the introduction line L1 (drainage introduction step). Here, the inorganic ion in the inorganic ion-containing wastewater may be, for example, a metal ion, a fluorine ion, a phosphate ion, a sulfate ion, a sulfite ion or a carbonate ion. Metal ion, for example ^{Fe 2 +, Fe 3 +,} Cu 2 +, Mn 2 +, Cr 2 +, Co 2 +, Ni 2 +, Zn 2 +, Cd 2 + , such as heavy metal ions and, Mg of ^3+, and the like of a light metal such as Al ^{+ 3} ion. At this time, in the first insoluble treatment tank 1, the pH adjuster is supplied from the pH adjuster supply tank 8 through the line L8 in order to agglomerate the sludge in the flocculation treatment tank 3. The pH of the crude inner liquid of the first insoluble treatment tank (1) is appropriately adjusted to a range of usually 4 to 12. The pH at this time differs depending on the generated insolubles. As the pH adjusting agent, for example, caustic soda, sulfuric acid, hydrochloric acid, or the like is used.

The effluent from the first insoluble treatment tank 1 is introduced into the second insoluble treatment tank 2 via the intermediate line L2. In the second insoluble treatment tank 2, the pH adjuster is supplied from the pH adjuster supply tank 9 through the line L9 in order to agglomerate the sludge in the flocculation treatment tank 3. At this time, the pH of the crude inner liquid of the second insoluble treatment tank (2) is appropriately adjusted to a predetermined range of pH 4 to 12, similarly to the first insoluble treatment tank (1). The pH at this time differs depending on the generated insolubles. For example, Al ^{3 +} , Fe ^{3 +} , F ^- and SO ₄ ^{2 -} have pH values of 6.0 to 8.0, Cr ^{2 +} , Cu ^{2 +} , Mn ^{2 +} , Ni ^{2 +} and Zn ^{2 +} PO ₄ ^- is adjusted in the range of pH 9.0 to 10.0. As the pH adjusting agent, caustic soda, sulfuric acid, or the like can be used as in the first insoluble treatment tank (1).

The effluent from the second insoluble treatment tank 2 is introduced into the coagulation treatment tank 3 via the intermediate line L3. In the coagulation treatment tank 3, the coagulant is supplied from the coagulant supply tank 10 through the line L10. The flocculant is not particularly limited as long as it has a flocculating function, but generally a polymer flocculant is used. The polymer flocculant may be a nonionic polymer flocculant, an anionic polymer flocculant, or a cationic polymer flocculant. However, when the inorganic ion-containing wastewater is aluminum-containing wastewater, Is effective as the polymer flocculant.

The drainage water from the flocculation treatment tank 3 is introduced into the sedimentation tank 4 through the intermediate line L4 and precipitated and separated into the treated water and the separated sludge 11 in the sedimentation tank 4 (sedimentation separation step). The treated water is discharged from the settling tank 4 through the treated water discharge line L7 (treated water discharge step).

In the present embodiment, a high-density sludge generation type water treatment apparatus is newly established with the establishment of a factory for discharging inorganic ion-containing wastewater. Because of this, the production of high-density sludge is started and the plant is in the stage where the film is newly built, so that the flow rate of the inorganic ion-containing wastewater discharged from the factory and the concentration of the inorganic ion are also small. Therefore, in the sedimentation tank 4, there is almost no separation sludge 11 present. For this reason, the separated sludge 11 is accumulated without operating the vane pump P1 for a while.

Eventually, when the plant is in full operation and the flow rate of the inorganic ion-containing wastewater discharged from the plant and the concentration of the inorganic ion are increased, the amount of the separated sludge 11 in the sedimentation tank 4 gradually increases.

In the sludge accumulation step, a region (sludge separation region) S 1 in the sedimentation tank 4 below the sludge interface S with respect to the volume of the region (reservoir inner liquid region) R 1 below the liquid level of the crude inner liquid of the sedimentation tank 4, ) (Hereinafter referred to as " sounch volume ratio ") (see Fig. 2). The sludge interface S refers to the top surface of the separated sludge region R2 and the sludge separation sludge 11 is contained in the separated sludge region R2.

Here, the sludge volume ratio can be determined as follows. That is, first, the positional relationship between the volume of the reservoir inner liquid area R1 of the sedimentation tank 4 and the surface of the inner reservoir liquid on the inner wall surface of the sedimentation tank 4 is checked in advance. By confirming this relationship, it is possible to determine the sludge volume ratio by confirming the position of the sludge interface S of the separated sludge area R2 in the inner tank liquid and the position of the liquid level L of the tank inner liquid. The position of the sludge interface S in the separated sludge region R2 can be confirmed by, for example, a sludge interface (not shown) provided in the sedimentation tank 4. [

Then, when the sludge volume ratio reaches a predetermined value of 5 to 15 vol%, a sludge circulation step, that is, a high density sludge generation step is started.

Specifically, at least a part of the separated sludge 11 from the settling tank 4 is supplied to the sludge reforming tank 5 via the separated sludge supply line L5 by the sludge supply pump P2 fair). At least a part of the separated sludge 11 is supplied to the sludge reforming tank 5, and only a part of the separated sludge 11 may be supplied, or all of the separated sludge 11 may be supplied.

In the sludge reforming tank 5, a counter ion-containing substance is introduced from a counter ion-containing substance supply tank (not shown) through a line L12. Thus, counter ions in the counter ion-containing material are adsorbed on the surface of the separated sludge 11 introduced into the sludge reforming tank 5 to form adsorbed sludge (adsorbed sludge production step). The counter ion-containing material may be one containing an inorganic ion and a counter ion capable of forming an insoluble matter. When the inorganic ion is, for example, a metal ion, a hydroxide ion is used as the counter ion. In this case, a substance containing a hydroxide ion such as Ca (OH) ₂ or NaOH may be used as the counter ion-containing substance. As the counter ion-containing material, it is also possible to use a substance containing a chloride ion, for example, CaCl ₂ . When the inorganic ion is a fluorine ion, as the counter ion, besides the hydroxide ion, Ca ^{2 +} can also be used. When the inorganic ion is a phosphate ion, a sulfate ion or a sulfite ion, Fe ^{2 +} , Fe ^{3 +} or Ca ^{2 +} can be used. The adsorbed sludge produced in this manner is supplied from the sludge reforming tank 5 to the first insoluble treatment tank 1 via the adsorbed sludge supply line L11. Then, in the first insoluble treatment tank (1), the inorganic ion-containing waste water and the adsorbing sludge are brought into contact with each other. Thereby, the inorganic ions in the inorganic ion-containing wastewater are caused to react with the counter ions of the adsorbed sludge to be insolubilized (insolubilization step). At this time, since the inorganic ion is insolubilized by reacting with the counter ion, the pH of the crude inner liquid of the first insolubilization tank (1) differs depending on the generated insoluble matter, Range. At this time, the pH can be adjusted by supplying the pH adjuster from the pH adjuster supply tank 8 through the line L8 as described above. As the pH adjusting agent, the above-described caustic soda, sulfuric acid, hydrochloric acid, or the like is used.

The effluent from the first insoluble treatment tank 1 is introduced into the second insoluble treatment tank 2 via the intermediate line L2. In the second insoluble treatment tank (2), the pH adjuster is supplied from the pH adjuster supply tank (9) through the line (L9). At this time, the pH of the crude inner liquid of the second insoluble treatment tank (2) is usually adjusted to a predetermined range of pH 4 to 12 according to the insolubilized material to be produced, similarly to the first insoluble treatment tank (1) Adjusted appropriately. As the pH adjusting agent, the above-described caustic soda and sulfuric acid can be used.

The effluent from the second insoluble treatment tank 2 is introduced into the coagulation treatment tank 3 via the intermediate line L3. In the coagulation treatment tank 3, the coagulant is supplied from the coagulant supply tank 10 through the line L10. As the coagulant, the above-mentioned coagulant is used.

The effluent from the flocculation treatment tank 3 is introduced into the settling tank 4 through the intermediate line L4 and settled and separated into the treated water and the separated sludge 11 in the settling tank 4 (settling and separation step). The treated water is discharged from the settling tank 4 through the treated water discharge line L7 (treated water discharge step).

As described above, at least a part of the separated sludge 11 from the sedimentation tank 4 is supplied to the sludge reforming tank 5 via the separated sludge supply line L5 by the sludge supply pump P2 (Separation sludge supply step).

By repeating the above-described series of steps, high-density sludge is produced.

Next, the control target value is set so that the sludge volume ratio becomes 30 vol% or less while continuing the generation and growth of the high-density sludge, and control is started (see Fig. 2).

At this time, a predetermined value is determined in advance within a range of 5 to 15 vol%, and the subsequent steps differ depending on whether the control target value of the sludge volume ratio is smaller than, equal to, or larger than the predetermined value.

(1) When the control target value of the sludge volume ratio is less than the predetermined value

After the start of the high-density sludge generation step, the vane pump P1 is operated to start the vane via the sludge discharge line L6, and the amount of sludge in the sedimentation tank 4 is reduced. Then, when the sludge volume ratio reaches the control target value, the output of the vane pump P1 is adjusted to limit the vane size, and the sludge volume ratio is controlled to be the control target value.

(2) When the control target value of the sludge volume ratio is equal to the predetermined value

After starting the high-density sludge production process, the vane pump P1 is operated to start the vane via the sludge discharge line L6, and the output of the vane pump P1 is adjusted to restrict the vinegar volume, Control target value.

(3) When the control target value of the sludge volume ratio is larger than the predetermined value

After the start of the high-density sludge generation process, the vane pump P1 is not operated and the vane is not started via the sludge discharge line L6. Then, the amount of sludge is increased, and the sludge volume ratio reaches the control target value. In this step, the vane pump P1 is operated to start the vane through the sludge discharge line L6, and the vinegar is carried out in the sedimentation tank 4 in small quantities. Then, by controlling the output of the vane pump P1, the amount of vanny is controlled to control the sludge volume ratio to be the control target value.

At this time, the engine speed is adjusted by outputting the pump P1 while monitoring the interface system (not shown), the sludge densitometer 7, and the like. The amount of vannai may be determined on the basis of the vanname rate and the vanny time by previously empirically confirming the vannithia per unit time (the vannicheat rate) during the moving process.

Specifically, in order to control the sludge volume ratio to be 30 vol% or less, the position of the sludge interface S is monitored by the sludge interface system provided in the settling tank 4, The separated sludge 11 may be discharged through the separated sludge supply line L5 and the sludge discharge line L6 by the vane pump P1.

By controlling the sludge volume ratio as described above, it is possible to suppress the decrease in the ratio of the high-density sludge in the separated sludge 11 in the sedimentation tank 4, and to suppress the generation delay of the high- Lt; / RTI > Therefore, according to the method of operating the high-density sludge generation type water treatment apparatus, high-density sludge can be sufficiently generated in a short period of time, and as a result, the concentration of high-density sludge can be increased in a short period of time. That is, the operation of the high-density sludge generation type water treatment apparatus can be performed in a short period of time. As a result, the main operation after the operation can be performed early. Further, if the sludge volume ratio in the sedimentation tank 4 is controlled to exceed 30 vol% of the volume, high-density sludge can not be sufficiently generated in a short period of time, and it takes a considerable time to increase the concentration of high-density sludge.

In this embodiment, in the sludge accumulation step performed in the early stage of the moving process, the sludge is once increased to a combined sludge amount (for example, 5 to 15 vol%), and then a high-density sludge generation step is performed. Thereby, sludge is taken into the sludge reforming tank 5, the first insolubilizing tank 1, the second insolubilizing tank 2 and the flocculation tank 3 in the process of circulating the sludge in the high-density sludge generation step Even when the amount of sludge finally returned to the sedimentation tank 4 is reduced, the amount of sludge required for generation of high-density sludge can be secured.

The sludge volume ratio is preferably controlled to be 4 to 30 vol%, more preferably 10 to 20 vol%. In this case, the high-density sludge concentration can be sufficiently increased in a shorter period of time during operation of the high-density sludge generation type water treatment apparatus. That is, the operation of the high-density sludge generation type water treatment apparatus can be performed in a shorter period of time. As a result, the main operation after the operation can be performed earlier.

The moving process is terminated as described above. Whether or not the moving process has been completed depends on whether or not the generation of the high-density sludge has been sufficiently performed. The criterion for determining whether or not the generation of the high-density sludge is sufficiently performed depends on the kind of the inorganic ion in the waste water to be treated. That is, when the inorganic ions are Al ^{3 +} , Fe ^{2 +} , Fe ^{3 +} , Cr ^{2 +} , F ^- , PO ₄ ^{2 -} or SO ₄ ^{2 -} , they easily increase the sludge concentration. Therefore, it is judged that the moving process is completed when the sludge concentration reaches a value arbitrarily set within the range of 150 to 350 g / L (preferably 200 to 300 g / L). On the other hand, when the inorganic ions are Cu ^{2 +} , Mn ^{2 +} , Ni ^{2 +} , or Zn ^{2 +} , they are difficult to raise the sludge concentration. Therefore, it is judged that the moving process is completed when the sludge concentration reaches a value set arbitrarily within the range of 50 to 150 g / l (preferably 80 to 120 g / l). The difference in the criterion for determining whether or not the high-density sludge is sufficiently generated depending on the kind of the inorganic ion differs depending on the ease of high density, in other words, ease of modification by the inorganic ion. The reason why high-density sludge is generated or not is determined based on the sludge concentration as follows. That is, it is difficult to confirm the crystal structure of the sludge in the field and to dry the sludge. Therefore, rather than directly measuring the sludge density, it is preferable to measure the sludge concentration and estimate the sufficiently high sludge density based on the sludge concentration This is because the determination of the termination of the process becomes easy.

When the movable process is completed as described above, the present operation process is performed. In this operation step, a sufficiently high density sludge is generated in the separated sludge 11 of the sedimentation tank 4. [ Therefore, it is not necessary to control the sludge volume ratio in the sedimentation tank 4 to be 30 vol% or less, so that it may be controlled to a sludge volume ratio exceeding 30 vol%. In this case, it is necessary to increase the amount of sludge in the sedimentation tank 4 after the end of the moving process. However, in this operation step, the sludge volume ratio in the sedimentation tank 4 is usually 50 vol% or less. Also, after the operation, the sintering ratio may be controlled to 30 vol% or less. In this case, the sintered volume ratio should be the same as the sintered volume ratio in the moving process.

≪ Second Embodiment >

Next, a second embodiment of the method for operating the high-density sludge generation type water treatment apparatus according to the present invention will be described in detail. In the present embodiment, when the high-density sludge generation type water treatment apparatus is provided with the sludge reforming tank 5 in a water treatment apparatus (hereinafter referred to as "existing water treatment apparatus") having no sludge reforming tank 5, The case where the existing water treatment apparatus is modified will be described. In the present embodiment, the same reference numerals are given to the same or equivalent components to those in the first embodiment, and redundant description is omitted.

When the existing water treatment apparatus is converted into a high density sludge generation type water treatment apparatus, the sludge reforming tank 5 is installed on the separated sludge supply line L5 while the water treatment operation by the existing water treatment apparatus is continued and the installation is completed And the separated sludge 11 from the settling tank 4 is supplied to the sludge reforming tank 5 to start the densification of the sludge. That is, the moving process is started. At this time, the factory that supplied the drainage to the existing water treatment apparatus is normally in a full operation state. As a result, the production of high-density sludge is started, the flow rate of the inorganic-ion-containing wastewater discharged from the plant and the concentration of the inorganic ion are increased, and a sufficient amount of the separated sludge 11 is often present in the settling tank 4 . Specifically, the separated sludge 11 is often present at a sludge volume ratio of 20 to 50 vol%.

Therefore, the present embodiment is different from the first embodiment in that the moving process does not include a sludge accumulation process. That is, in the present embodiment, the control is started so that the sludge volume ratio in the sedimentation tank 4 is 30 vol% or less without accumulating sludge in the sedimentation tank 4. Here, when the sludge volume ratio in the sedimentation tank 4 is larger than 30 vol% at the start of the moving process, the sludge amount is reduced by operating the vane pump P1. Then, after the sludge volume ratio reaches the control target value of 30 vol% or less, the sludge volume ratio is controlled to be the control target value. On the other hand, when the sludge volume ratio in the sedimentation tank 4 is 30 vol% or less at the start of the moving process, the sludge amount is increased or decreased by operating the vane pump P1 as necessary. Then, after the sludge volume ratio reaches the control target value of 30 vol% or less, the sludge volume ratio is controlled to be the control target value.

The present invention is not limited to the above-described embodiments. For example, although the coagulation treatment tank 3 is formed in the above embodiment, the coagulation treatment tank 3 may be omitted.

Example

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to the following Examples.

<Al drainage>

(Example 1)

The operation of the high-density sludge generation type water treatment apparatus shown in Fig. 1 was carried out in the following manner. In the high-density sludge generation type water treatment apparatus, the separation sludge 11 was not present in the sedimentation tank 4, that is, the sludge volume ratio in the sedimentation tank 4 was 0%.

(Hereinafter referred to as &quot; Al drainage &quot;) having an aluminum ion concentration of 1000 mg / l as an inorganic ion-containing wastewater to be treated is introduced into the first insolubilization treatment tank 1 ).

At this time, the pH value was adjusted by suitably supplying sulfuric acid so that the pH value in the crude inner solution of the first insoluble treatment tank (1) was about 6.5. However, in the first insolubilization treatment tank (1), the pH fluctuates greatly. The effluent from the first insoluble treatment tank 1 was introduced into the second insoluble treatment tank 2 via the intermediate line L2. In the second insoluble treatment tank 2, caustic soda and sulfuric acid, which are pH adjusters as appropriate, are supplied from the pH adjuster supply tank 9 via a line L9 to the second insolubilization tank 2, Was adjusted so as to have a pH value of 7.0.

The effluent from the second insoluble treatment tank 2 was introduced into the coagulation treatment tank 3 via the intermediate line L3. In the coagulation treatment tank 3, the polymer flocculant was supplied from the flocculating agent supply tank 10 via the line L10.

The effluent from the flocculation treatment tank 3 was introduced into the settling tank 4 via the intermediate line L4 and settled and separated into the treated water and the separated sludge in the settling tank 4. The treated water was discharged from the settling tank 4 via the treated water discharge line L7. The sludge was accumulated in the sedimentation tank 4 in this way.

Then, while accumulating the sludge, the sludge volume ratio in the sedimentation tank 4 was measured.

Here, the sieve volume ratio was determined as follows. That is to say, first, the positional relationship between the volume of the reservoir inner liquid area R1 of the sedimentation tank 4 and the surface of the inner reservoir liquid on the inner wall surface of the sedimentation tank 4 is checked in advance, The position of the sludge interface S and the position of the liquid level L of the crude inner liquid were checked to determine the sludge volume ratio. The position of the sludge interface S of the separated sludge region R2 was confirmed by a sludge interface system (not shown) provided in the sedimentation tank 4. [

In this embodiment, the sludge is first accumulated to 10 vol%, and when the sludge volume ratio reaches 10 vol%, the sludge circulation step, that is, the high density sludge generation step, is started.

Specifically, a part of the separated sludge from the settling tank 4 was first supplied to the sludge reforming tank 5 via the separated sludge supply line L5 by the sludge supply pump P2. On the other hand, calcium hydroxide, which is a counter ion-containing substance, was introduced into the sludge reforming tank 5 via the line L12. Then, the introduced calcium hydroxide was adsorbed on the surface of the separated sludge 11 to produce adsorbed sludge.

Then, the adsorbed sludge is supplied from the sludge reforming tank 5 to the first insolubilization treatment tank 1 via the adsorbing sludge supply line L11. In the first insolubilizing tank 1, The sludge was contacted. Thus, the aluminum ion in the Al wastewater was insolubilized by reacting with the hydroxide ion which is the counter ion of the adsorbed sludge. At this time, the pH was adjusted by supplying sulfuric acid as a pH adjuster from the pH adjuster supply tank 8 via line L8.

The effluent from the first insoluble treatment tank 1 was introduced into the second insoluble treatment tank 2 via the intermediate line L2. In the second insoluble treatment tank 2, caustic soda and sulfuric acid, which are pH adjusting agents, were supplied from a pH adjuster supply tank 9 through a line L9.

The effluent from the second insoluble treatment tank 2 was introduced into the coagulation treatment tank 3 via the intermediate line L3. In the coagulation treatment tank (3), a polymer flocculant was supplied from the flocculating agent supply tank (10).

The effluent from the flocculation treatment tank 3 was introduced into the settling tank 4 via the intermediate line L4 and settled and separated into the treated water and the separated sludge 11 in the settling tank 4. [ The treated water was discharged from the settling tank 4 via the treated water discharge line L7.

The above-described series of steps were repeated to produce a high-density sludge. On the other hand, after the sludge volume ratio reached 10 vol%, the sludge volume ratio in the sedimentation tank 4 was reduced to 3 vol% by carrying out the vat in the sedimentation tank 4.

Thereafter, the sludge was densified by controlling the sludge volume ratio to be 3 vol% by carrying out a vanname in the sedimentation tank 4. [

Here, the sludge volume ratio in the sedimentation tank 4 was determined as follows. That is to say, the positional relationship between the volume of the tank inner fluid introduced into the settling tank 4 and the surface position of the inner tank inner fluid on the inner wall surface of the settling tank 4 is checked in advance and based on this relationship, The ratio of the volume of the separated sludge region R2 in the soil innerwear liquid region R1 to the sludge volume ratio S .

Specifically, the control of the sludge volume ratio in the settling tank 4 was carried out as follows. In other words, the output of the vane pump P1 was adjusted to restrict the vane volume so that the sludge volume ratio became the control target value. The position of the sludge interface S is monitored by monitoring the position of the sludge interface S using a sludge interface system provided in the settling tank 4 so that the position of the sludge interface S greatly deviating from the position at which the sludge volume ratio becomes 3 vol% When confirmed, the amount of sludge discharged directly was adjusted appropriately.

Thus, the high-density sludge generation type water treatment apparatus was operated as described above.

(Example 2)

The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 1 except that the sludge volume ratio was controlled to be 4 vol%.

(Example 3)

The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 1 except that the sludge volume ratio was controlled to be 6 vol%.

(Example 4)

The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 1 except that the sludge volume ratio in the sedimentation tank 4 was controlled to be 10 vol% after the sludge volume ratio reached 10 vol% .

(Example 5)

Even after the sludge volume ratio reached 10 vol%, the amount of sludge was continuously increased in the settling tank 4, and after the sludge volume ratio in the settling tank 4 reached 15 vol%, the sludge volume ratio was 15 vol %, The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 1.

(Example 6)

Even after the sludge volume ratio reached 10 vol%, the amount of sludge was increased in the settling tank 4, and the sludge volume ratio in the settling tank 4 reached 20 vol% after the sludge volume ratio reached 20 vol% %, The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 1.

(Example 7)

Even after the sludge volume ratio reached 10 vol%, the amount of sludge was increased in the settling tank 4, and after the sludge volume ratio reached 25 vol%, the sludge volume ratio in the settling tank 4 was 25 vol %, The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 1.

(Example 8)

Even after the sludge volume ratio reached 10 vol%, the amount of sludge was continuously increased in the settling tank 4, and after the sludge volume ratio reached 30 vol%, the sludge volume ratio in the settling tank 4 was 30 vol %, The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 1.

(Comparative Example 1)

Even after the sludge volume ratio reached 10 vol%, the amount of sludge in the settling tank 4 was increased to reach 32 vol%, and the sludge volume ratio in the settling tank 4 was 32 vol.%, the operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 1.

(Comparative Example 2)

Even after the sludge volume ratio reaches 10 vol%, the amount of sludge in the sedimentation tank 4 is increased, and after the sludge volume ratio reaches 50 vol%, the sludge volume ratio in the sedimentation tank 4 becomes 50 vol.%, the operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 1.

The separated sludge 11 (sludge concentration (C1)) in the sedimentation tank 4 was taken out at intervals of one day for each of the operation methods of Examples 1 to 8 and Comparative Examples 1 and 2, put in a measuring cylinder, The concentration ratio R of the sludge after standing was measured as the ratio of the capacity of the sludge region in the measuring cylinder (the capacity of the sludge region after standing for 24 hours / the capacity of the sludge region before standing for 24 hours) And the concentration C2 (= C1 / R) was calculated. At this time, the sludge concentration (C1) was measured with a sludge densitometer (7). Then, in each of Examples 1 to 8 and Comparative Examples 1 and 2, the time until the sludge concentration (C2) reached 300 g / l was measured. The results are shown in Table 1.

3 is a graph showing the results of time-course changes in sludge concentration in the sedimentation tank 4 with respect to Example 4 and Comparative Example 1. Fig.

As shown in Table 1, the operating methods of Examples 1 to 8 show that the time required for the sludge concentration to reach 300 g / l is remarkably shortened as compared with the operating methods of Comparative Examples 1 and 2. This is obvious from FIG. That is, when comparing the plot of Example 4 with the plot of Comparative Example 1, it can be seen that the plot of Example 4 and the plot of Comparative Example 1 are largely separated from the start of measurement over time. From this, it is clear that the sludge concentration of Example 4 reaches 300 g / l in a short period of time as compared with Comparative Example 1. Also, the same tendency was observed for the period of reaching 150 g / l and 200 g / l. Here, the sludge concentration of 150 g / l is a reference sludge concentration at which high-density sludge is sufficiently generated.

From the results shown in Table 1, it was found that the time for reaching the sludge concentration to 300 g / l was remarkably shortened, especially by setting the sludge volume ratio of the sedimentation tank 4 to 5 vol% to 25 vol%.

Therefore, according to the present invention, it was confirmed that the operation of the high-density sludge generation type water treatment apparatus to be treated with the Al wastewater can be performed in a short period of time.

<Fe drainage>

(Example 9)

An inorganic ion-containing wastewater to be processed, containing multiple iron ions from the aluminum drain (iron ions (Fe ^{3 +)} concentration: 1000 mg / ℓ) counter ions to be supplied to the change, and the sludge modified tank (5) containing material, The pH in the first insolubilization treatment tank 1 and the pH in the second insolubilizing treatment tank 2 are set as shown in Table 2 and the pH in the sedimentation tank 4 ) Was operated so as to have a sludge volume ratio of 15 vol%, the operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 5.

(Comparative Example 3)

The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 9 except that the sludge volume ratio in the sedimentation tank 4 was controlled to be 35 vol%.

<Cr drainage>

(Example 10)

The inorganic ion containing wastewater to be treated is changed from aluminum wastewater to chrome ion containing wastewater (chromium ion (Cr ^{2 +} ) concentration: 1000 mg / l) The pH in the first insolubilization treatment tank 1 and the pH in the second insolubilizing treatment tank 2 are set as shown in Table 2 and the concentration of the counter ions forming the sedimentation tank 4 ) Was controlled so as to have a sludge volume ratio of 13 vol%, the operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 5.

(Comparative Example 4)

The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 10 except that the sludge volume ratio in the sedimentation tank 4 was controlled to be 33 vol%.

<F multiple>

(Example 11)

The inorganic ion containing wastewater to be treated is changed from aluminum wastewater to fluorine ion containing wastewater (fluorine ion (F ^- ) concentration: 1000 mg / l), and the counter ion containing substance supplied to the sludge reforming tank 5, The pH in the first insolubilization treatment tank 1 and the pH in the second insolubilization treatment tank 2 are set as shown in Table 2, Was operated so as to have a sludge volume ratio of 10 vol% in the same manner as in Example 4, the operation of the high-density sludge generation type water treatment apparatus was carried out.

(Comparative Example 5)

The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 11 except that the sludge volume ratio in the sedimentation tank 4 was controlled to be 32 vol%.

<PO ₄ drainage>

(Example 12)

The inorganic ion-containing wastewater to be treated is changed from aluminum wastewater to phosphoric acid ion-containing wastewater (phosphate ion (PO ₄ ^{2 -} ) concentration: 1000 mg / , The pH in the first insolubilization treatment tank (1) and the pH in the second insolubilization treatment tank (2) were set as shown in Table 2, and the concentration of the counter ions in the sedimentation tank 4 was operated so as to have a sludge volume ratio of 10 vol%, the operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 4.

(Comparative Example 6)

The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 12 except that the sludge volume ratio in the sedimentation tank 4 was controlled to be 33 vol%.

<SO ₄ drainage>

(Example 13)

The inorganic ion-containing wastewater to be treated was changed from aluminum wastewater to sulfate ion-containing wastewater (sulfate ion (SO ₄ ^{2 -} ) concentration: 1000 mg / , The pH in the first insolubilization treatment tank (1) and the pH in the second insolubilization treatment tank (2) were set as shown in Table 2, 4 was operated so as to have a sludge volume ratio of 10 vol%, the operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 4.

(Comparative Example 7)

The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 13 except that the sludge volume ratio in the sedimentation tank 4 was controlled to be 33 vol%.

Separated sludge 11 (sludge concentration (C1)) in the sedimentation tank 4 was taken out at intervals of one day for each of the operating methods of Examples 9 to 13 and Comparative Examples 3 to 7, put in a measuring cylinder, The concentration ratio R of the sludge after standing was measured as the ratio of the capacity of the sludge region in the measuring cylinder (the capacity of the sludge region after standing for 24 hours / the capacity of the sludge region before standing for 24 hours) And the concentration C2 (= C1 / R) was calculated. At this time, the sludge concentration (C1) was measured with a sludge densitometer (7). Then, in each of Examples 9 to 13 and Comparative Examples 3 to 7, the time until the sludge concentration (C2) reached 300 g / l was measured. The results are shown in Table 2.

4 is a graph showing the results of time-course changes in sludge concentration in the sedimentation tank 4 with respect to Example 9 and Comparative Example 3. Fig. 5 is a graph showing the results of Example 10 and Comparative Example 4, 6 is a graph showing the results of time-course changes of the sludge concentration in the sedimentation tank 4. Fig. 6 is a graph showing the results of time-course changes of the sludge concentration in the sedimentation tank 4 with respect to Example 11 and Comparative Example 5 7 is a graph showing the results of time-course changes of sludge concentration in the sedimentation tank 4 with respect to Example 12 and Comparative Example 6, and Fig. 8 is a graph showing the results of Example 13 and Comparative Example 7 In the sedimentation tank 4 with respect to the sludge concentration.

As shown in Table 2, the operating methods of Examples 9 to 13 were found to remarkably shorten the time required for the sludge concentration to reach 300 g / l, as compared with the operating methods of Comparative Examples 3 to 7. [ This is obvious from FIG. 4 to FIG. That is, for example, when comparing the plot of Example 9 with the plot of Comparative Example 3, it can be seen that the plots of Example 9 and Comparative Example 3 are largely separated from the start of measurement to the time elapsed. From this, it is apparent that the sludge concentration in Example 9 reaches 300 g / l in a short period of time as compared with Comparative Example 3. Also, the same tendency was observed for the period of reaching 150 g / l and 200 g / l. This result was also the same in the operating methods of Examples 10 to 13.

Therefore, according to the present invention, it was confirmed that the operation of the high-density sludge generation type water treatment apparatus to be treated with Fe drainage, Cr drainage, F drainage, PO ₄ drainage and SO ₄ drainage can be performed in a short period of time.

<Cu drainage>

(Example 14)

An inorganic ion-containing wastewater to be processed, the copper ion-containing wastewater from the aluminum drain (copper ion (Cu ^{2 +)} concentration of 1000 mg / ℓ) changes to the sludge modified tank (5) containing a counter-ion to be supplied to the material, copper Ion and the pH in the first insolubilization treatment tank (1) and the pH in the second insolubilization treatment tank (2) were set as shown in Table 3, and the sludge volume ratio Was controlled so as to be 12 vol%, the operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 5.

(Comparative Example 8)

The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 14 except that the sludge volume ratio was controlled to be 33 vol%.

<Mn drainage>

 (Example 15)

The inorganic ion containing wastewater to be treated is changed from aluminum wastewater to manganese ion containing wastewater (manganese ion (Mn ^{2 +} ) concentration: 1000 mg / l) The pH in the first insolubilization treatment tank (1) and the pH in the second insolubilization treatment tank (2) were set as shown in Table 3, and the counter ion forming the sludge volume The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 5 except that the ratio was controlled to be 12 vol%.

(Comparative Example 9)

The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 15 except that the sludge volume ratio was controlled to be 32 vol%.

<Ni drainage>

(Example 16)

The inorganic ion-containing wastewater to be treated is changed from aluminum wastewater to nickel ion-containing wastewater (nickel ion (Ni ^{2 +} ) concentration: 1000 mg / The pH in the first insolubilization treatment tank 1 and the pH in the second insolubilizing treatment tank 2 are set as shown in Table 3 and the counter ions forming the insoluble matter in the sedimentation tank 4 ) Was controlled so as to have a sludge volume ratio of 12 vol%, the operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 5.

(Comparative Example 10)

The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 16 except that the sludge volume ratio in the sedimentation tank 4 was controlled to be 33 vol%.

<Zn drainage>

(Example 17)

An inorganic ion-containing wastewater to be processed, a multiple-containing zinc ions from the aluminum drain (zinc ion (Zn ^{2 +)} concentration of 1000 mg / ℓ), the counter-ion to be supplied to the change, and the sludge modified tank (5) containing material, zinc The pH in the first insolubilization treatment tank 1 and the pH in the second insolubilization treatment tank 2 are set as shown in Table 3, Was operated so as to have a sludge volume ratio of 12 vol.%, The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 5.

(Comparative Example 11)

The operation of the high-density sludge generation type water treatment apparatus was carried out in the same manner as in Example 17 except that the sludge volume ratio in the sedimentation tank 4 was controlled to be 33 vol%.

Separated sludge 11 (sludge concentration (C1)) in the sedimentation tank 4 was taken at intervals of one day for each of the operation methods of Examples 14 to 17 and Comparative Examples 8 to 11, put in a measuring cylinder, The concentration ratio R of the sludge after standing was measured as the ratio of the capacity of the sludge region in the measuring cylinder (the capacity of the region after 24 hours of standing / the capacity of the sludge region before standing for 24 hours) C2 (= C1 / R) was calculated. At this time, the sludge concentration (C1) was measured with a sludge densitometer (7). In each of Examples 14 to 17 and Comparative Examples 8 to 11, the time until the sludge concentration (C2) reached 100 g / l was measured. The results are shown in Table 3.

10 is a graph showing the results of time-course changes of sludge concentration in the sedimentation tank (4) with respect to Example 14 and Comparative Example 9, and Fig. 11 is a graph showing the results of Example 15 and Comparative Example 10, 12 is a graph showing the results of time-course changes of the sludge concentration in the sedimentation tank 4 with respect to Example 17 and Comparative Example 11, FIG.

As shown in Table 3, in the operation methods of Examples 14 to 17, it was found that the time required for the sludge concentration to reach 100 g / l was remarkably shortened as compared with the operation methods of Comparative Examples 8 to 11. This is obvious from FIG. 9 to FIG. That is, for example, when the plots of Example 14 and Comparative Example 8 are compared with each other, it can be seen that plots of Example 14 and Comparative Example 8 are largely separated from the start of measurement to the time course. From this, it is apparent that the sludge concentration of Example 14 reached 100 g / l in a short period of time as compared with Comparative Example 8. Also, the same tendency was observed for the period of reaching 50 g / l and 80 g / l. This result was also the same in the operating methods of Examples 14 to 17. [

Thus, according to the present invention, it was confirmed that the operation of the high-density sludge generation type water treatment apparatus to be treated with Cu drainage, Mn drainage, Ni drainage and Zn drainage can be performed in a short period of time.

One… The first insolubilization treatment tank
2… The second insolubilization treatment tank
3 ... Coagulation treatment tank
4… Sedimentation tank
5 ... Sludge reforming tank
L5 ... Separation sludge supply line
L12 ... Line (counter ion-containing material supplying means)
V1 ... Valve (counter ion containing substance supply means)
R1 ... The inner liquid area
R2 ... Separation sludge area
S ... Sludge interface
L ... Liquid face

Claims (7)

An insolubilization treatment tank for insolubilizing inorganic ions in the introduced inorganic ion-containing wastewater,
A sedimentation tank for precipitating and separating the effluent water introduced from the above-mentioned insolubilization treatment tank into treated sludge and separated sludge,
A separated sludge supply line for connecting the sedimentation tank and the insolubilization treatment tank,
And a counter ion containing substance containing a counter ion which forms an insoluble matter with the inorganic ion is adsorbed on the surface of the separated sludge introduced on the separated sludge supply line from the sedimentation tank via the separated sludge supply line, A sludge reforming tank for supplying the obtained adsorbed sludge to the insolubilization treatment tank,
And a counter ion-containing substance supplying means for supplying the counter ion-containing substance to the sludge reforming tank,
The inorganic ion-containing wastewater introduced into the insolubilization treatment tank is brought into contact with the adsorbed sludge supplied from the sludge reforming tank and the inorganic ions in the inorganic ion-containing wastewater are reacted with the counter ions of the adsorbed sludge to insolubilize And
A sedimentation separation step of sedimentating and separating the effluent water introduced from the above-mentioned insolubilization treatment tank into treated water and separated sludge in the settling tank;
A separation sludge supply step of supplying at least a part of the separated sludge discharged from the settling tank to the sludge reforming tank via the separated sludge supply line,
Density sludge is produced by repeating the adsorbing sludge generation step of adsorbing the counterion-containing material on the surface of the separated sludge introduced into the sludge reforming tank to generate adsorbed sludge, thereby to obtain a high-density sludge- In the method for operating the high-density sludge generation type water treatment apparatus performed before the main operation,
And a high-density sludge generation step of producing high-density sludge from the low-density sludge in the apparatus,
(Sludge volume ratio), which is the ratio of the volume of a region (separated sludge area) below the sludge interface in the sedimentation tank to the volume of the region (reservoir inner-liquid region) below the level of the crude inner fluid of the sedimentation tank during the high- vol% or less of the total amount of the sludge. The method according to claim 1,
And the sludge volume ratio is controlled to be 4 to 30 vol%. The method according to claim 1,
A waste water introducing step of introducing the inorganic ion-containing waste water into the insolubilization treatment tank;
Further comprising a treated water discharging step of discharging the treated water obtained by sedimentation separation in the sedimentation tank,
Wherein the inorganic ion-containing wastewater is plant wastewater. The method according to claim 1,
Prior to the dense sludge production process,
Sludge accumulation step of introducing the inorganic ion-containing wastewater into the insolubilization treatment tank, sedimentation separation of effluent water introduced from the insolubilization treatment tank into treated sludge and separated sludge in the sedimentation tank, and sludge accumulation in the sedimentation tank Including,
Wherein the sludge volume ratio is 0 vol% at the start of the sludge accumulation step. 5. The method of claim 4,
A predetermined value is determined in advance within a range of 5 to 15 vol%
Wherein when the control target value of the sludge volume ratio is less than the predetermined value, the sludge volume ratio reaches a predetermined value in the sludge accumulation step, and in the high-concentration sludge generation step, And controlling the sludge volume ratio to be the control target value while performing the vannishing in the settling tank after the sludge volume ratio reaches the control target value,
Wherein when the control target value of the sludge volume ratio is equal to the predetermined value, the sludge volume ratio is controlled to be the control target value while the sludge is carried out in the sedimentation tank in the high-
Wherein when the control target value of the sludge volume ratio is larger than the predetermined value, the sludge volume ratio reaches the predetermined value in the sludge accumulation step, and in the high density sludge generation step, The sludge volume ratio in the settling tank is increased and the sludge volume ratio is controlled to be the control target value while the sludge volume ratio is reached to the control target value and the sludge is subjected to the vat in the settling tank Wherein the high-density sludge-producing type water treatment apparatus is operated. 6. The method according to any one of claims 1 to 5,
The inorganic ion is at least one selected from the group consisting of Al ^{3 +} , Fe ^{2 +} , Fe ^{3 +} , Cr ^{2 +} , F ^- , PO ₄ ^{2 -} or SO ₄ ^{2 -} and a predetermined value set within the range of 150 to 350 g / The operation of the high-density sludge generation type water treatment apparatus is judged to be completed. 6. The method according to any one of claims 1 to 5,
When the inorganic ion is Cu ^{2 +} , Mn ^{2 +} , Ni ^{2 +} or Zn ^{2 +} , and the sludge concentration reaches a predetermined value set within a range of 50 to 150 g / l, it is judged that the moving process is finished Wherein the high-density sludge generation type water treatment apparatus comprises:

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