JP2009119405A - Method for volume-reducing treatment of discharged sludge attendant upon water purification and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for volume-reducing treatment of discharged sludge attendant upon water purification and an apparatus therefor which are installed in a water purification plant, by which treatment time of discharged muddy water attendant upon water purification treatment is short and further an installation area required for treatment may be comparatively narrow. <P>SOLUTION: In the apparatus for volume-reducing treatment of discharged sludge attendant upon water purification installed in the water purification plant, the muddy water, which is discharged at a process of subjecting raw water to water purification treatment and sending treated water to a water supply pond, is sent into a neutralization tank 30, the raw water from the neutralization tank 30 is adjusted to alkalinity and then is blended with an inorganic flocculant to subject floating solid in the raw water to flocculation treatment. Floc-containing water is sent to a rapid granulating precipitate thickening tank 31, an anionic polymer is supplied to the rapid granulating precipitate thickening tank 31 and blending by low speed agitation is performed in a granulation tank of the rapid granulating precipitate thickening tank 31 to cause flocculation. Obtained highly granulated matter is subjected to discharged sludge volume-reducing treatment. Thus the highly granulated matter is subjected to dehydration treatment and dehydrated cake is discharged. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method and apparatus for reducing the volume of purified water wastewater at a water purification plant capable of reducing the volume of purified water sludge by high-speed and advanced coagulation treatment of the sludge water generated in the water purification process.

  There is a method of pure water treatment using only chlorination of raw water, but recently, river water has been contaminated and suspended solids (hereinafter referred to as SS) in the raw water taken into the intake well have been settled in a sedimentation basin. A flocculant (polyaluminum chloride: hereinafter referred to as PAC) is introduced, and the overflow water is passed through slow filtration, and the filtrate water is chlorinated and sent. The filtration method is a cross-flow type or inclined plate type. There are a sedimentation basin system, a high-speed coagulation sedimentation basin system, and the like, and further, water purification treatment is performed by a membrane filtration system using an MF / UF membrane as a method of SS membrane filtration concentration.

  Here, the high-speed coagulation sedimentation basin system will be described with reference to the drawings. FIG. 4 shows a water purification system in which raw water 1 taken from river water, lake water, or the like is sent to a high-speed coagulation sedimentation basin 3 or is sent to a high-speed coagulation sedimentation basin 3 through a landing well 2. A chemical (flocculant such as PAC) is introduced, and the overflow water in the high-speed coagulation sedimentation basin 3 is sent to the rapid filtration basin 4. The overflow water in the rapid filtration basin 4 is sent to the chlorination well 5 and subjected to chlorination, and is sent to the water purification basin 6 to the water supply. The drainage sludge and backwash drainage discharged from the high-speed coagulation sedimentation basin 3 and the rapid filtration basin 4 are discharged to the drainage basin 7 and sent to the mud basin 8. Waste water from the waste mud pond 8 is concentrated in the concentration tank 9, and the concentrated sludge is sent to the dehydration facility 10 for dehydration. In a facility without a dehydration facility, sludge water is sent to the sun drying bed 11 and subjected to sun drying treatment. This sun-dried floor 11 requires a vast site and dehydration time, and causes a bad odor.

  Recently, the eutrophication of rivers and lakes throughout the country has progressed, and seasonal changes in processing volume and changes in the quality of raw water SS have reached the limit of the capacity of permanent equipment. Due to the increase in phytoplankton and green algae, there is an increase in off-flavours and mold odors in tap water. To remove the musty odor of tap water, there is a method in which powdered activated carbon is added to a coagulating sedimentation tank and adsorbed, and such treatment methods are often employed in water purification plants. As a conventional purification method corresponding to such a problem, for example, there is a purification method shown in FIG. This purification treatment method is a treatment method that combines a sand filtration method, an activated carbon adsorption method, and a membrane filtration method. When described with reference to FIG. 5, raw water from the landing well 2 is sent to the settling basin 12, Overflow water is sent to the sand filtration pond 13, the treated water is sent to the activated carbon adsorption pond 14, and the purified water is sent to the water supply. In addition, cleaning wastewater containing sludge settled in the sedimentation basin 12, sand filtration basin 13, and activated carbon adsorption basin 14 SS is sent to the sewage basin 15, and the overflow water from the sewage basin 15 is sent to the cleaning effluent adjustment basin 16. Then, the membrane is treated in the membrane treatment tank 17, the treated water is sent to the membrane treatment water tank 18, and the settled sludge discharged from the sewage pond 15 and the washing drainage adjustment basin 16 and the concentrated sludge discharged from the membrane treatment water tank 18. The water is sent to the concentration tank 19 and concentrated (see Patent Document 1).

Japanese Patent Laid-Open No. 10-165990

  In the water treatment plant, the wastewater is concentrated in the final concentration tank and discharged as a dehydrated cake in the dewatering facility. During the concentration, the wastewater or sludge is sent to the sun drying bed and concentrated. Yes. Such a treatment method using a sun-drying bed requires a large amount of treatment land, requires a long number of days for dehydration, is affected by the weather, and the water treatment capacity depends on seasonal factors, resulting in a decrease in water treatment capacity. There was a risk of bringing about. In addition, it can be a cause of foul odors, so it is a difficult treatment method in densely populated areas such as urban areas, and in existing areas where eutrophication due to rapid pollution of rivers and the like is progressing, expansion of treatment facilities Often difficult to do on site.

  The conventional purification method (Patent Document 1) is a treatment method in which an activated carbon adsorption method and a membrane filtration method are combined with a sand filtration method. For membrane filtration, a hollow fiber membrane module using a microfiltration membrane (MF membrane) is used. Membrane modules such as flat membrane modules are used, and there is a drawback that maintenance management for periodically replacing the membrane modules to prevent deterioration of the water treatment capacity is complicated, and sedimentation of sewage ponds etc. When the sludge and the concentrated sludge water by membrane treatment are sent to the concentration tank and mixed, and when the dehydration process is performed with a filter press or the like, it is necessary to further promote the aggregation and precipitation process of SS, and the dehydration time is 24. It takes about an hour and a long time.

  This invention is made | formed in view of the above subjects, The processing time of the sludge installed in a water treatment plant and discharged | emitted with a water purification process is short, and also the installation area required for a process may be comparatively narrow. An object of the present invention is to provide a method and an apparatus for reducing the volume of purified water discharge mud.

The present invention achieves the above-mentioned problem, and the invention of claim 1 is a purified water waste mud volume reducing device in a water purification plant,
Wastewater discharged in the process of purifying the raw water and sending it to the distribution reservoir is sent to the neutralization reaction tank, and the neutralization reaction tank is used to adjust the pH value of the raw water to the alkaline range, and The material is mixed with an inorganic flocculant and flocculated into a floc form, sent to a high-speed granulation precipitation concentration tank, an anionic polymer is supplied to the high-speed granulation precipitation concentration tank, It is a purified water waste mud volume reducing device in a water treatment plant characterized in that it is a highly agglomerated material that is agglomerated and flocked by mixing at low speed in a granulation tank, and the highly agglomerated material is discharged as a dehydrated cake. .

Further, the invention of claim 2 is characterized in that the high-speed granulation sedimentation concentration tank supplies treated water obtained by agglomeration treatment by supplying the inorganic flocculant to the alkaline raw water from the neutralization reaction tank, and the anion. A mixing tank for supplying and mixing the functional polymer;
A granulation tank to be a highly granulated product obtained by pelletizing the aggregated floc obtained by mixing in the mixing tank with low speed stirring;
2. The apparatus for reducing the volume of purified water drainage at a water purification plant according to claim 1, wherein the apparatus comprises a sedimentation tank in which the highly granulated product supplied from the granulation tank is precipitated and drains the treated water. is there.

  Further, the invention of claim 3 is provided with a wide inclined ridge spanned between the granulation tank and the settling tank, and the highly granulated material passes from the granulation tank through the inclined ridge to the precipitation tank. It is made to flow in substantially the center, The purified water waste mud volume reduction processing apparatus in the purified water treatment plant of Claim 1 or 2 characterized by the above-mentioned.

  In the invention of claim 4, the sludge in the sedimentation tank measures the interface position of the deposited slurry interface where the highly granulated material in the sedimentation tank is dispersed with a sludge interface meter, and the interface position becomes a predetermined value. When it reaches | attains, it controls so that the highly granulated material which precipitates in the said sedimentation tank may be discharged | emitted with a discharge pump, The purified water waste mud volume reduction processing apparatus in the water purification plant of Claim 2 or 3 characterized by the above-mentioned. is there.

  The invention according to claim 5 is characterized in that the inorganic flocculant is aluminum sulfate, and the mixing amount of aluminum sulfate is 300 to 500 mg / l with respect to the raw water. It is a purified water waste mud volume reduction processing apparatus in the water purification plant of 1 item | term.

  The invention of claim 6 is characterized in that the addition amount of the anionic polymer to the high-speed granulation precipitation concentration tank is 20 to 30 mg / l with respect to the mud water. It is the purified water waste mud volume reduction processing apparatus in the water purification plant of Claim 1.

Moreover, the invention of claim 7 is a method for reducing the volume of purified water wastewater treatment at a water purification plant,
Wastewater discharged in the process of purifying the raw water and sending it to the distribution reservoir is sent to the neutralization reaction tank, and the neutralization reaction tank is used to adjust the pH value of the raw water to an alkaline range, and the suspended solids in the raw water Is mixed with an inorganic flocculant to agglomerate in a floc form, fed to a high-speed granulation precipitation concentration tank, and an anionic polymer is supplied to the high-speed granulation precipitation concentration tank. A method for reducing the volume of purified water wastewater at a water treatment plant, wherein the agglomerated flocs are produced by stirring at a low speed in a granule tank to produce a highly granulated product and discharging the highly granulated product as a dehydrated cake. It is.

The invention according to claim 8 is characterized in that the high-speed granulation precipitation concentration tank supplies treated water obtained by agglomeration treatment by supplying the inorganic flocculant to the alkaline raw water from the neutralization reaction tank, and the anion. A mixing tank for supplying and mixing the functional polymer;
A granulation tank to be a highly granulated product obtained by pelletizing the aggregated floc obtained by mixing in the mixing tank with low speed stirring;
The method according to claim 7, comprising a precipitation tank in which the highly granulated product supplied from the granulation tank is precipitated and drains the treated water. is there.

  Further, the invention of claim 9 is provided with a wide inclined ridge spanned between the granulation tank and the settling tank, and the highly granulated product passes through the inclined ridge from the granulation tank. It is made to flow in substantially the center, It is a purified water waste mud volume reduction processing method in the purified water treatment plant of Claim 7 or 8.

  In the invention of claim 10, the sludge in the settling tank measures the interface position of the slurry interface where the highly granulated material in the settling tank is dispersed with a sludge interface meter, and the interface position reaches a predetermined value. It is controlled so that the highly granulated material which precipitates in the said sedimentation tank may be discharged | emitted with a discharge pump, when it carries out, It is the purified water waste mud volume reduction processing method in the water purification plant of Claim 8 or 9 characterized by the above-mentioned. .

  The invention of claim 11 is characterized in that the inorganic flocculant is aluminum sulfate, and the mixing amount of aluminum sulfate is 300 to 500 mg / l with respect to the raw water. It is a purified water waste mud volume reduction processing method in the water treatment plant of item 1.

  The invention of claim 12 is characterized in that the addition amount of the anionic polymer to the high-speed granulation precipitation concentration tank is 20 to 30 mg / l with respect to the mud water. It is a purified water waste mud volume reduction processing method in the water purification plant of Claim 1.

In invention of Claim 1, it is a purified water waste mud volume reduction processing apparatus in a water purification plant,
Wastewater discharged in the process of purifying the raw water and sending it to the distribution reservoir is sent to the neutralization reaction tank, and the neutralization reaction tank is used to adjust the pH value of the raw water to the alkaline range, The material is mixed with an inorganic flocculant and agglomerated in a floc form, sent to a high-speed granulation precipitation concentration tank, an anionic polymer is supplied to the high-speed granulation precipitation concentration tank, Purified water sludge volume reduction processing equipment in a water treatment plant characterized by mixing by low speed stirring in a granulation tank to form a high-granulated product obtained by pelletizing agglomerated flocs and discharging the highly-granulated product as a dehydrated cake Therefore, it is possible to reduce the volume of sludge discharged from the water treatment plant at a high speed in an emergency and discharge it as a dehydrated cake in a short time, and it is a relatively compact treatment device. To increase the water treatment capacity of the plant There is an advantage that you can.

Moreover, in the invention of claim 2, the high-speed granulation precipitation concentration tank supplies the inorganic flocculant by supplying the inorganic flocculant to the alkaline raw water from the neutralization reaction tank, and feeds the treated water. A mixing tank for supplying and mixing the functional polymer;
A granulation tank to be a highly granulated product obtained by pelletizing the aggregated floc obtained by mixing in the mixing tank with low speed stirring;
2. The apparatus for reducing the volume of purified water drainage at a water purification plant according to claim 1, wherein the apparatus comprises a sedimentation tank in which the highly granulated product supplied from the granulation tank is precipitated and drains the treated water. Therefore, the raw water from the neutralization reaction tank sent to the high-speed granulation precipitation concentration tank is kept alkaline, and the aggregate flocs are formed by the aluminum sulfate and the anionic polymer of the coagulation aid supplied in the subsequent process. It has the advantage of being able to granulate highly agglomerated highly dense granulated particles with a high density of dense and strong soil particles, which can reduce the production time of the highly granulated product, Contributes to the improvement of sludge volume reduction capacity at water treatment plants.

  Moreover, in invention of Claim 3, the wide inclination slag spanning the said granulation tank and the said precipitation tank is provided, and the said highly granulated material passes through this inclination slag from this granulation tank, and the said sedimentation tank Since it is the purified water sludge volume reduction processing apparatus in the water purification plant of Claim 1 or 2 characterized by flowing in the substantially center, highly granulated material does not obstruct | occlude with a slanting stagnation. The sludge is fed into the approximate center of the settling tank as a slide, and the highly granulated material is evenly dispersed in the settling tank and does not accumulate in an abnormally offset shape. There is an advantage not to destroy. Moreover, if the bottom part of a sloping gutter is a V-shaped groove | channel, highly granulated material will slide without being stagnated along the slope of a V-shaped groove | channel, and will be smoothly sent into a sedimentation tank.

  In the invention of claim 4, the sludge in the settling tank measures the interface position of the deposited slurry interface where the highly granulated material in the settling tank is dispersed with a sludge interface meter, and the interface position becomes a predetermined value. When it reaches, it is controlled to discharge the highly granulated material that settles in the settling tank with a discharge pump. In the settling tank in the high-speed granulation precipitation concentration tank, the deposited slurry layer and the treated water due to the highly granulated product (concentrated sludge) are separated to form an interface, and the interface between the deposited slurry layer and the treated water, that is, the deposited slurry. An interface is formed, and this deposition slurry interface is measured with a sludge interface meter to detect the rise of this interface, and when it rises to a predetermined position, control is performed to discharge the concentrated sludge in the sedimentation tank. Keep the slurry interface low Accordingly, an advantage of eliminating the possibility that highly granules in the treated water to overflow from the sedimentation tank (concentrating sludge) flows out. The amount of suspended matter generated and the quality of the raw water (change in the ratio of organic matter to inorganic matter) also depend on the degree of algal growth in the wastewater storage tank due to weather conditions such as the SS concentration, temperature and sunshine duration of the raw water. However, the amount of highly granulated product produced and the compactness of the concentrated sludge vary. By measuring the deposited slurry interface in the settling tank with a sludge interface meter and controlling the concentrated sludge to be discharged when it reaches a certain interface, the sludge volume reduction capacity of the water purification process can be improved.

  The invention according to claim 5 is characterized in that the inorganic flocculant is aluminum sulfate, and the mixing amount of aluminum sulfate is 300 to 500 mg / l with respect to the raw water. Since it is a purified water sludge volume reducing treatment apparatus in the water treatment plant described in Item 1, sulfuric acid is added to alkaline sludge water to which sodium hydroxide (caustic soda) is added in the neutralization reaction tank as pretreatment for advanced granulation. By mixing a large amount of aluminum, the property that the flocs due to sodium hydroxide are fine and easy to break is eliminated, and the fine agglomerated flocs are agglomerated and highly agglomerated by the injection of the anionic polymer in the next stage, which is dense and strong There is an advantage that it is possible to granulate a highly granulated product having a large particle size and pelletized with a high density of soil particles.

  Moreover, in invention of Claim 6, the addition amount to the said high-speed granulation precipitation concentration tank of the said anionic polymer is 20-30 mg / l with respect to wastewater, Any of Claim 1 to 5 characterized by the above-mentioned. Since it is a water purification sludge volume reduction processing apparatus in the water treatment plant according to claim 1, agglomerated flocs of aluminum sulfate are further agglomerated by injecting an anionic polymer, and the pellets are highly granulated with a large particle size. There is an advantage that a product can be generated, and the waste mud water discharged by the water purification treatment can be separated and concentrated efficiently, so that the sludge volume reduction treatment efficiency of the water purification treatment can be increased.

Moreover, in invention of Claim 7, it is a purified water waste mud volume reduction processing method in a water purification plant,
Wastewater discharged in the process of purifying the raw water and sending it to the distribution reservoir is sent to the neutralization reaction tank, and the neutralization reaction tank is used to adjust the pH value of the raw water to an alkaline range, and the suspended solids in the raw water Is mixed with an inorganic flocculant to agglomerate in a floc form, fed to a high-speed granulation precipitation concentration tank, and an anionic polymer is supplied to the high-speed granulation precipitation concentration tank. A water purification sludge volume reduction treatment method in a water treatment plant characterized by producing a high-granulated product that is agglomerated and flocked by stirring at low speed in a granule tank, and discharging the highly-granulated product as a dehydrated cake. As a result, the sludge discharged during the water purification process is highly agglomerated at high speed to produce highly granulated pellets with agglomerated frog with a large particle size, and the waste mud is concentrated and reduced to be discharged as a dehydrated cake. There are advantages that can be done.

  Moreover, in the invention of claim 8, the high-speed granulation precipitation concentration tank supplies the inorganic coagulant to the raw water made alkaline by the neutralization reaction tank and feeds the treated water, and the anionic property A mixing tank for supplying and mixing the polymer, a granulating tank for forming a highly granulated product obtained by pelletizing the agglomerate floc obtained by mixing in the mixing tank with low speed stirring, and an advanced granulation supplied from the granulating tank The method for reducing the volume of purified water wastewater in the water treatment plant according to claim 7, characterized in that it comprises a settling tank for precipitating granules and draining the treated water. The treated water from the neutralization reaction tank to be sent is kept alkaline, and the aggregated frog is highly aggregated in the granulation tank by the aluminum sulfate and anionic polymer supplied in the post-process, and the soil is dense and strong. Pellet with high particle density There is an advantage that it is possible to granulate highly granulated products with a large particle size, it is possible to shorten the generation time of highly granulated products, and contribute to the improvement of sludge volume reduction capacity of the water treatment plant .

  Moreover, in invention of Claim 9, the wide inclination slag spanning the said granulation tank and the said precipitation tank is provided, and the said highly granulated material passes through this inclination slag from this granulation tank, and the said sedimentation tank Since it is a purified water waste mud volume reduction processing method in the water treatment plant according to claim 7 or 8, the highly granulated material is stagnated and blocked in the granulation tank. Without being inclined, the sludge is fed into the center of the settling tank as a slide, and the highly granulated material is evenly dispersed by the stirring blades in the settling tank, and does not accumulate in an abnormally offset shape, and rotates at a low speed. There is an advantage that highly granulated material is not destroyed by the wing. Moreover, if the bottom part of a sloping gutter is a V-shaped groove | channel, highly granulated material will slide without being stagnated along the slope of a V-shaped groove | channel, and will be smoothly sent into a sedimentation tank.

  In the invention of claim 10, the sludge in the settling tank measures the interface position of the slurry interface where the highly granulated material in the settling tank is dispersed with a sludge interface meter, and the interface position reaches a predetermined value. It is a purified water waste mud volume reduction processing method in the water treatment plant according to claim 8 or 9, characterized in that, when the water is discharged, the highly granulated material precipitated in the settling tank is controlled to be discharged by a discharge pump. In the settling tank in the high-speed granulation precipitation concentration tank, the deposited slurry layer and the treated water are separated from the highly granulated product (concentrated sludge) to form an interface, and the interface between the deposited slurry layer and the treated water, that is, the deposition A slurry interface is formed, and by measuring the deposited slurry interface with a sludge interface meter, the rise of this interface is detected, and when it rises to a predetermined position, it is controlled to discharge the concentrated sludge in the settling tank, The position of the deposited slurry interface is constant By keeping low the altitude granules from settling tank to the overflow processing solution (concentrated sludge) is an advantage of eliminating the risk of contamination. In addition, the amount of suspended matter produced varies depending on the degree of algal reproduction in the wastewater storage tank due to weather conditions such as SS concentration, temperature and sunshine duration of raw water, Sludge volume reduction treatment of water purification treatment by controlling the sludge interface to measure the sludge interface in the sedimentation tank and the concentration sludge is forcibly discharged when it reaches a certain interface. Ability can be improved.

  In the invention of claim 11, the inorganic flocculant is aluminum sulfate, and the mixing amount of aluminum sulfate is 300 to 500 mg / l with respect to the raw water. Since it is a method for reducing the volume of purified water wastewater treatment at the water treatment plant described in Item 1, the pretreatment for advanced granulation and the treatment of aluminum sulfate with sodium hydroxide (caustic soda) added in the neutralization reactor Addition of a large amount of aluminum sulfate to alkaline sludge water prevents the lack of alkalinity due to the addition, agglomeration flocs are formed, and the compaction of highly granulated products produced by injecting anionic polymer is destroyed. Eliminates easy properties, highly agglomerates fine agglomerated flocs, granulates agglomerated flocs with high density and solid pellets with high density and strong soil particle density There is the advantage that it is possible.

  Moreover, in invention of Claim 12, the addition amount of the said anionic polymer to the said high-speed granulation precipitation concentration tank is 20-30 mg / l with respect to waste water, Any of Claim 7 to 11 characterized by the above-mentioned. The water purification sludge volume reduction treatment method in the water treatment plant according to claim 1, further agglomerates the finely flocculated flocs by aluminum sulfate with an anionic polymer to produce a pelletized highly granulated product with a large particle size The waste mud discharged by the water purification treatment can be treated efficiently, and the sludge volume reduction efficiency of the water purification treatment can be increased.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a water purification / mud volume reduction processing method and an apparatus therefor in a water purification plant of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention, and shows a process of highly concentrating wastewater discharged from a wastewater pond of a water purification plant. FIG. 2 shows a process of discharging sludge water discharged in the process of highly concentrating the waste mud water as a dehydrated cake through a device or the like that further increases the concentration. Fig. 3 (a) shows a schematic side view of a high-speed granulation and precipitation apparatus as a main part of the present embodiment, Fig. 3 (b) is a schematic top view thereof, and Fig. 3 (c) is a schematic cross-sectional view of an inclined gutter. It is.

  First, the water purification process will be described with reference to FIG. Reference numeral 20 denotes a water purification treatment process. The raw water 21 taken from the river / lake is sent to the high-speed coagulation sedimentation basin 23 through the landing well 22 or directly from the raw water 21 to the high-speed coagulation sedimentation basin 23. In the high-speed coagulation sedimentation basin 23, a flocculant such as polyaluminum chloride (PAC) is injected into the raw water to floculate and precipitate SS in the raw water, and the supernatant water of the high-speed coagulation sedimentation basin 23 is allowed to overflow and the rapid filtration basin 24 Water. The treated water filtered in the rapid filtration basin 24 is sent to the chlorine injection well 25, and chlorine is injected into the treated water in the water supply process and the chlorine injection well 25, and chlorine is also injected before and after the chlorine injection well 25. Then, it is sterilized, sent to the water purification pond 26 and sent out as drinking water.

  A floc settles at the bottom of the high-speed coagulating sedimentation basin 23, and a concentrated slurry is generated and circulated. A certain amount of sludge is discharged to the drainage basin 27, and in the rapid filtration basin 24, the backwash drainage that has washed the filter layer is drained. It is discharged to the pond 27. The sludge water stored in the drainage basin 27 and the supernatant water of the backwash drainage are returned to the landing well 22, and the precipitated sludge is drained into the mud basin 28 to be drained mud and purified water wastewater volume reduction process. Is discharged. The SS per unit of wastewater discharged to the purified water wastewater volume reduction treatment step may be a thin SS concentration of 300 to 4000 mg / l, or when there is a concentration tank such as an existing thickener, You may concentrate to about 6000-15000 mg / l, and you may send to a purified water waste mud volume reduction process. The SS concentration sent to the purified water waste mud volume reduction process is approximately 1000 to 15000 mg / l, and the volume of purified water waste mud can be reduced.

  The purified water waste mud volume reducing process of the waste water discharged in the above water purification process is processed by the apparatus mainly composed of the raw water tank 29, the neutralization reaction tank 30, the high speed granulation sedimentation treatment device 31 and the discharge tank 34. Furthermore, the sludge water discharged from the high-speed granulation sedimentation processing device 31 and the discharge tank 34 is concentrated in the sludge storage tank 35 and the sludge concentrator 36, dehydrated by the dehydrator 40 and discharged as a dehydrated cake. . This water purification mud volume reduction process is a process that is not carried out at the water purification plant, and will be described in detail below.

  First, the discharged mud water is fed to the raw water tank 29 and stored, and then fed to the neutralization reaction tank 30. Sodium hydroxide (caustic soda) is supplied from the caustic soda injection device 30a to the neutralization reaction tank 30, and the pH of the waste mud water in the neutralization reaction tank 30 is raised to 9.0 to make it alkaline. The mud water made alkaline in the neutralization reaction tank 30 is sent to the high-speed granulation / precipitation treatment apparatus 31. As described below, aluminum sulfate (sulfuric acid band) is used as a flocculant for facilitating separation and precipitation of suspended solids in the sludge in the stage before being supplied to the granulation tank of the high-speed granulation / precipitation treatment apparatus 31. In this case, the pH value of the drainage mud is lowered to 6.0 to 5.5 and sodium hydroxide is added to the neutralization reaction tank 30 in order to prevent the mud from being acidified. Supply and make wastewater alkaline. When the pH value of the sludge water when mixing aluminum sulfate (sulfuric acid band) is reduced to 6.0 to 5.5, the flocs flocs are reduced, or when the alkalinity is insufficient, the flocs are not agglomerated. Gets worse. Therefore, the alkalinity is maintained so that the pH value of the mud water in the neutralization reaction tank 30 does not drop below 9.0, and the pH value of the mud water in the neutralization reaction tank 30 after mixing the sulfuric acid band is around 8. To maintain.

  The high-speed granulation / precipitation treatment apparatus 31 is composed of a line mixer, a mixing tank, a granulation tank, a precipitation tank, and the like, and aluminum sulfate is supplied from an aluminum sulfate injection device 32 into a water supply pipe through which alkaline waste mud water is fed to the mixing tank. Furthermore, an anionic polymer is supplied as an organic polymer flocculating aid from the automatic chemical dissolution apparatus 33 to the bottom of the mixing tank, and a highly granulated product is generated by suspended matter (flocculated floc) of waste water. Water flows over to the discharge tank 34 and is discharged into the river. This highly granulated product is an agglomerated floc that is strong and dense with an anionic polymer and has a high density of aggregated flocs, that is, a highly granulated product that has been pelletized. It has a diameter of 5 to 10 mm which does not pass on the net.

  As shown in FIGS. 3 (a) to 3 (c), the high-speed granulation / precipitation treatment apparatus 31 includes a line mixer 31 a, a mixing tank 31 b, a granulation tank 31 c, a precipitation tank 31 e, and the like. The aluminum sulfate is supplied from the aluminum sulfate injection device 32 to the water pipe to which alkaline waste mud water is sent, and is agglomerated and rapidly mixed by the line mixer 31a and sent to the mixing tank 31b. 400 mg / l of aluminum sulfate is injected per unit volume of waste water. In the mixing tank 31b, the anionic polymer is automatically supplied into the mixing tank 31b from the chemical automatic dissolving device 33 and mixed, and the agglomerated mixed water is fed into the granulating tank 31c from the lower part of the granulating tank 31c. Stirring is performed by the stirring blade M1 of the granulation tank 31c. The anionic polymer is injected near the bottom of the mixing tank 31b, the supply amount to the unit volume of the coagulated mixed water is 30 mg / l, and is agitated at a low speed in the granulating tank 31c to produce highly granulated products by suspended substances. Thus, a slurry floating layer (slurry bracket layer) is formed. The amount of the anionic polymer supplied is at least 10 times the amount used in ordinary turbid water treatment. In this embodiment, 30 mg / l is added, which improves the cross-linking action between flocs and improves the slurry bracket. The layer produces strong dense pellets. By rotating the stirring blade M1 of the granulation tank 31c at a low speed of 15 rpm, the agglomerated flocs do not leave and grow into flocs with high agglomeration density, and pelletized highly granulated products are generated. In the granulation tank 31c, the specific gravity of the highly granulated product is heavier than that of water, but as the treated water in the tank is continuously processed by the stirring blade, the inside of the granulation tank 31c gradually moves upward as it aggregates. The fine flocs in the floc mixed water in the granulation tank 31c are collected in the middle floc layer in the granulation tank 31c. The highly granulated product in which the aggregation flocs are highly agglomerated is continuously agglomerated, so that the agglomerated flocs move to the upper part of the granulation tank 31c as it agglomerates and float in the upper part from the middle part of the granulation tank 31c. A layer of material (slurry blanket layer) is formed. The pelletized highly granulated product of the slurry blanket layer is pushed up by the highly granulated product generated while collecting fine agglomerated flocs, and is settling through an inclined gutter 31d provided on the upper part of the granulating vessel 31c. It is sent to 31e.

  As shown in FIGS. 3B and 3C, the inclined ridge 31d is a wide inclined ridge having a V-shaped bottom groove, and the wide inclined ridge (inclined ridge) 31d is composed of a granulation tank 31c and a precipitation tank. 31e is provided so as to be inclined downward toward the settling tank 31e side, and the highly granulated product pushed up to the upper part of the granulating tank 31c passes through the inclined trough 31d and is substantially at the center of the settling tank 31e. It is provided to flow into the part. The inclined ridge 31d is formed into a wide inclined ridge having a V-shaped groove, so that the highly granulated product is formed so as to float up and overflow as the pelletized highly granulated product is generated. Without falling in the granule tank 31c and the inclined basket 31d, it slides down along the V-shaped slope of the V-shaped groove portion of the inclined basket 31d, and is smoothly fed into the sedimentation tank 31e. The highly granulated product naturally falls into the sedimentation tank 31e at a sedimentation speed of 500 mm / min or more. In addition, the outlet of the highly granulated product of the inclined trough 31d is in the vicinity of the center of the settling tank 31e, and the stirring blade M2 of the settling tank 31e is low speed so that the generated highly granulated product is not destroyed. Rotate. The outlet of the inclined tub 31d is in the vicinity of the center of the settling tank 31e so that the highly granulated material is fed to the axis center of the stirring blade M2 so that it is evenly distributed around the stirring axis of the settling tank 31e. If the outlet of the inclined tub 31d is located at a position offset from the axial center of the stirring blade M2 of the settling tank 31e, highly granulated material is deposited immediately below the inclined granule 31d, and a deposit of highly offset granulated material is formed. There is a possibility that the result of destroying the highly granulated material on which the stirring blade M2 is deposited and the sludge meter 31f may discharge mud due to different sensing. In addition, the inclined gutter 31d is provided with a wide guide wall on the inlet side of the highly granulated product, and the guide wall is provided along the upper inner wall surface of the granulation tank 31c. The granulated material is prevented from stagnation and clogging, the collection of the highly granulated material is made good, the transfer to the sedimentation tank 31e is made easy, and the outlet of the inclined gutter 31d is slightly squeezed. Thus, the highly granulated product may be poured into the center (the axis center of the stirring blade M2) (not shown).

  In the sedimentation tank 31e, the highly granulated material falls toward the bottom of the sedimentation tank 31e. The concentrated sludge at the bottom of the settling tank 31e is stirred by the stirring blade M2 to be concentrated to an SS concentration of 3 to 4% wt, settled at the bottom of the settling tank 31e, and the concentrated sludge is discharged by the sludge pump 31h. Is done. In addition, the clear treated water that is solid-liquid separated in the sedimentation tank 31e is sent to and stored in the discharge tank 34 as overflow water, and treated water having an SS concentration of about 25 mg / l is drained to the river. Further, the concentrated sludge settles in a layered manner at the bottom of the sedimentation tank 31e, and the concentrated sludge layer and the treated water are clearly separated in the sedimentation tank 31e, and the interface between the deposited slurry layer and the treated water (deposited slurry interface) ) Is formed. Further, when this interface rises, there is a risk that the concentrated sludge of the deposited slurry layer is mixed into the overflow water and flows out to the discharge tank 34. In this embodiment, the sludge interface meter 31f is installed in the sedimentation tank 31e, and the detection signal of the sludge interface meter 31f is input to the control device 31g to measure the deposited slurry interface. When the sludge interface meter 31f detects the interface position between the deposited slurry layer and the treated water and the controller 31g detects that the interface position has risen to a predetermined position, the sludge pump is based on the control signal from the controller 31g. 31h is operated, and the concentrated sludge accumulated at the bottom of the sedimentation tank 31e is controlled to be forcibly discharged by the mud pump 31h. By performing such control, it is possible to prevent a large amount of agglomerated floc (advanced granulated material) from flowing into the discharge tank 34 together with the overflow water. In addition, even if the SS concentration of the raw water (sludge water) discharged from the water purification process is significant, the seasonal variation of the SS concentration can be controlled by controlling the discharge of the concentrated sludge in the settling tank 31e. Therefore, it is possible to efficiently treat the wastewater, which contributes to improving the water purification efficiency.

  On the other hand, the concentrated sludge discharged from the settling tank 31e and the concentrated sludge water deposited in the discharge tank 34 are sent to and stored in the sludge storage tank 35 as shown in FIG. A certain amount of concentrated sludge is sent to the sludge concentrator 36, 0.48% of the anionic polymer is added per dry solid (KgDS) from the chemical automatic dissolving device 37, and the cationic polymer is added from the chemical automatic dissolving device 38. Is added at 0.4% per dry solid (KgDS). At the outlet of the sludge concentrator 36, the sludge is concentrated until the SS concentration of the concentrated sludge is 6.5 to 8.3% wt. Then, it is sent to the dehydrator 40 by the concentrator conveyor 39. In the dehydrator 40, the cationic polymer is added from the automatic chemical dissolution apparatus 38 by 0.1% per dry sludge (KgDS) of the concentrated sludge to improve the dehydration property, and the SS concentration is 20 to 25 at the outlet of the dehydrator 40. Dehydrated to% wt (water content: 80-75%). The dehydrated cake discharged from the dehydrator 40 is stored in the dehydrated cake container 42 by the cake container 41 and is transported outside the water purification plant. The sludge concentrator 36 is a belt-type natural concentrator, and the dehydrator 40 is a belt press dehydrator, for example.

  This embodiment is not limited to the form of FIG. 1 as a water purification process, and can be applied to various water purification processes. In addition, the treated water discharged from the high-speed granulation sedimentation treatment device is drained into the river or used as washing water, then treated again and drained into the river, but it can be used as washing water on the purified water side. No water is sent to the water purification pond.

  As an application example of the present invention, there is a water purification mud volume reduction treatment method and its treatment device in a water treatment plant, and the water purification treatment efficiency is increased by using the alternative to a water treatment plant having an existing sun drying bed. It can be used for reducing sludge volume in a short time in an emergency.

It is a block diagram which shows one Embodiment of this invention. In this embodiment, it is a block diagram which shows the process in which the sludge water discharged | emitted in the process of highly concentrating waste water is discharged | emitted as a dewatering cake. (A) shows the schematic side view of the high-speed granulation precipitation apparatus of the principal part of this embodiment, (b) is the schematic top view, (c) is a schematic sectional drawing of an inclined gutter. It is a block diagram which shows the conventional water purification method. It is a block diagram which shows the other conventional water purification method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Water purification process 21 Raw water 22 Landing well 23 High-speed coagulation sedimentation basin 24 Rapid filtration basin 25 Chlorine injection well 26 Purification basin 27 Drainage pond 28 Sludge basin 29 Raw water tank 30 Neutralization reaction tank 30a Caustic soda injection device 31 High-speed granulation precipitation process Equipment 31a Line mixer 31b Mixing tank 31c Granulation tank 31d Tilting tank 31e Sedimentation tank 31f Sludge interface meter 31g Controller 31h Sludge pump 32 Aluminum sulfate injection device 33, 37, 38 Automatic chemical dissolution device 34 Discharge tank 35 Sludge storage tank 36 Sludge Concentrator 39 Concentrator conveyor 40 Dehydrator 41 Cake container 42 Dehydrated cake container

Claims (12)

A water purification mud volume reducing device at a water treatment plant,
Wastewater discharged in the process of purifying the raw water and sending it to the distribution reservoir is sent to the neutralization reaction tank, and the neutralization reaction tank is used to adjust the pH value of the raw water to the alkaline range, and The material is mixed with an inorganic flocculant and flocculated into a floc form, sent to a high-speed granulation precipitation concentration tank, an anionic polymer is supplied to the high-speed granulation precipitation concentration tank, A water purification mud volume reduction treatment apparatus in a water purification plant, wherein the granulated tank is mixed with low-speed agitation to form an agglomerated flocked highly granulated product, and the highly granulated product is discharged as a dehydrated cake. The high-speed granulation precipitation concentration tank is supplied with the inorganic flocculant by supplying the inorganic flocculant to the alkaline raw water from the neutralization reaction tank, and is fed with the anionic polymer for mixing. A tank,
A granulation tank to be a highly granulated product obtained by pelletizing the aggregated floc obtained by mixing in the mixing tank with low speed stirring;
2. The apparatus for reducing the volume of purified water wastewater treatment at a water purification plant according to claim 1, comprising a settling tank for precipitating highly granulated material supplied from the granulating tank and draining the treated water. A wide inclined ridge spanned between the granulation tank and the settling tank is provided, and the highly granulated product flows from the granulation tank through the inclined ridge into the approximate center of the precipitation tank. The purified water waste mud volume reduction processing apparatus in the water purification plant according to claim 1 or 2. The sludge in the settling tank measures the interface position of the deposited slurry interface where the highly granulated material in the settling tank is dispersed with a sludge interface meter, and settles in the settling tank when the interface position reaches a predetermined value. It controls so that the advanced granulated material to discharge may be discharged | emitted with a discharge pump, The purified water waste mud volume reduction processing apparatus in the water purification plant of Claim 2 or 3 characterized by the above-mentioned. In the water purification plant according to any one of claims 1 to 4, wherein the inorganic flocculant is aluminum sulfate, and the mixed amount of aluminum sulfate is 300 to 500 mg / l with respect to raw water. Clean water drainage volume reduction processing equipment. The water purification plant according to any one of claims 1 to 5, wherein the amount of the anionic polymer added to the high-speed granulation sedimentation concentration tank is 20 to 30 mg / l with respect to the discharged mud water. Water purification mud volume reduction processing equipment. A method for reducing the volume of purified water wastewater at a water treatment plant,
Wastewater discharged in the process of purifying the raw water and sending it to the distribution reservoir is sent to the neutralization reaction tank, and the neutralization reaction tank is used to adjust the pH value of the raw water to an alkaline range, and the suspended solids in the raw water Is mixed with an inorganic flocculant to agglomerate in a floc form, fed to a high-speed granulation precipitation concentration tank, and an anionic polymer is supplied to the high-speed granulation precipitation concentration tank. A purified water waste mud volume reducing treatment method in a water purification plant characterized by producing a high-granulated product that is agglomerated and flocked by mixing at low speed in a granule tank, and discharging the highly-granulated product as a dehydrated cake. The high-speed granulation precipitation concentration tank is supplied with the inorganic flocculant by supplying the inorganic flocculant to the alkaline raw water from the neutralization reaction tank, and is fed with the anionic polymer for mixing. A tank,
A granulation tank to be a highly granulated product obtained by pelletizing the aggregated floc obtained by mixing in the mixing tank with low speed stirring;
The method for reducing the volume of purified water wastewater at a water purification plant according to claim 7, characterized in that it comprises a sedimentation tank in which the highly granulated product supplied from the granulation tank is precipitated and the treated water is drained. A wide inclined ridge spanned between the granulation tank and the settling tank is provided, and the highly granulated product flows from the granulation tank through the inclined ridge into the approximate center of the precipitation tank. The method for reducing the volume of purified water wastewater in a water purification plant according to claim 7 or 8. The sludge in the settling tank measures the interface position of the slurry interface where the highly granulated material in the settling tank is dispersed with a sludge interface meter, and settles in the settling tank when the interface position reaches a predetermined value. It controls so that highly granulated material may be discharged | emitted with a discharge pump, The purified water waste mud volume reduction processing method in the water purification plant of Claim 8 or 9 characterized by the above-mentioned. The inorganic flocculant is aluminum sulfate, and the mixing amount of aluminum sulfate is 300 to 500 mg / l with respect to raw water.
To 10. The method for reducing the volume of purified water drainage in the water purification plant according to any one of 1 to 10. The water treatment plant according to any one of claims 7 to 11, wherein the amount of the anionic polymer added to the high-speed granulation precipitation concentration tank is 20 to 30 mg / l with respect to the discharged mud water. Water purification mud volume reduction processing method.

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