KR101634233B1 - Wastewater treatment system for reducing sludge - Google Patents

Abstract

The present invention relates to a wastewater treatment system for sludge reduction and, more particularly, to a wastewater treatment system for sludge reduction based on chemical and mechanical excess sludge pre-treatment resulting in an increase in sludge solubility and biodegradability. According to the present invention, excess sludge is drawn from a membrane separation-type active sludge treatment device, moisture content of the excess sludge is reduced by moisture content reducing means, and then pre-treatment is performed by an excess sludge pre-treatment reaction tank for solubility and biodegradability enhancement. Then, transport toward the membrane separation-type active sludge treatment device or an anoxic tank is performed for a significant reduction in sludge treatment amount. Accordingly, treatment costs can be reduced to a significant extent. In addition, nitrogen removal efficiency can be enhanced by an additional carbon source required for nitrogen removal being supplied. Furthermore, the present invention has a high level of phosphorus removal efficiency.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewage treatment system for reducing sludge,

The present invention relates to a sewage treatment system for reducing sludge in sewage treatment technology. More particularly, the present invention relates to a sewage treatment system for reducing sludge by promoting and increasing the solubility and biodegradability of sludge through chemical and mechanical pretreatment of surplus sludge, To a sewage treatment system.

Membrane separation activated sludge method is used as one of the conventional sludge reduction techniques.

As shown in FIGS. 4 and 5, the membrane-separated activated sludge process can obtain a stable treated water quality by maintaining a high concentration of microorganisms in the reaction tank, and can further reduce the volume of the reaction tank. And it is widely applied to small-scale sewage treatment or heavy water treatment.

However, as is the case with most biological wastewater treatment methods, it is becoming a problem of maintenance and costing factors for the treatment of excess sludge as a result of biological degradation of pollutants.

That is, the membrane separation activated sludge method has a small installation area and is easy to operate automatically as compared with the activated sludge method, which is a general sewage treatment method, and it can solve the problems such as sludge bulking by not including a settling tank separately And has been widely used in small-scale sewage treatment facilities.

This is especially true in the case of small-scale heavy water treatment facilities in line with the recent policy consideration for water reuse because the quality of the treated water can be adjusted according to the selection of the membrane.

Membrane separation Activated sludge process, like other biological treatment methods, accumulates sludge as a result of decomposition of pollutants and microorganism growth. It keeps the concentration of sludge in the reactor at a certain level by extracting an appropriate amount of sludge for stable operation It is necessary.

The excess sludge generated as a result of the sludge drawing is generally subjected to separate concentration, dehydration and drying processes to reduce the volume, and the final cake is buried or incinerated.

In general, the treatment cost of such sludge accounts for a large part of the total water treatment cost. Especially, in case of the membrane separation activated sludge method which is widely used for small-scale sewage treatment, There is a problem of a considerable burden on the side.

Moreover, recently, regulations related to the final treatment of sludge have been strengthened, and the processing of existing methods such as direct landfill, incineration, and marine dumping has become increasingly difficult, and the cost is also increasing.

As a conventional technique for partially solving the problems of the prior art, Korean Patent Registration No. 10-0419259 (Feb. 2, 2004) entitled " Sewage Treatment Method Using Sludge Reducing Membrane Separation Activated Sludge Process "

However, in the case of the above-mentioned registered patent, since the sludge reduction rate is low, the improvement is required.

Korea Patent Registration No. 10-0419259 (registered on Mar. 02, 2004) "Sewage Treatment Method Using Sludge Reducing Membrane Separation Activated Sludge Process"

It is an object of the present invention to provide a sewage treatment method using a membrane separation activated sludge process, and more particularly, to a process for treating a sludge using a chemical and mechanical pretreatment of an excess sludge, And to provide a sewage treatment system for reducing sludge that promotes and increases biodegradability and reduces sludge.

In order to accomplish the above object, the present invention provides a membrane separation type activated sludge treatment device for treating sewage water using a membrane separation type water treatment method in which a separation membrane is immersed in a membrane separation aeration tank by solid- The sludge pretreatment reaction tank and the coagulant dosage unit, wherein the alkaline chemical is added to the excess sludge pretreatment tank to increase the solubility and biodegradability of the sludge and selectively transport the sludge to the anoxic tank and membrane separation aeration tank, Accelerate biodegradation and capitalization of sludge, and reduce sludge generation; The sludge is heated to alkali during the alkali treatment to accelerate and increase the solubility and biodegradability of the sludge or to reduce the sludge so as to promote and increase the solubility and biodegradability of the sludge by ball milling treatment after alkali treatment of the drawn sludge The sewage treatment system comprising: The surplus sludge pre-treatment tank is connected to the membrane separation aerobic tank and the anoxic tank through an excess sludge conveyance pipe and a pretreatment sludge conveyance pipe, an excess sludge conveyance pump is installed in the excess sludge conveyance pipe, Further comprising a water content reducing means for reducing the water content of the sludge before the pretreatment reaction of the excess sludge pretreatment tank so as to increase the treatment efficiency, wherein the water content reducing means comprises a sedimentation separating water from the excess sludge introduced from the excess sludge return pipe Liquid separator, a mobile gravity type solid-liquid separator for separating moisture from the sludge sludge while transferring the separated sludge from the sedimentation type solid-liquid separator, and a sludge conveyor And a drying device A microbial food storage tank for storing microbial food to be fed to the aerobic microorganisms; a microbial food storage tank for storing the microbial food to be fed to the aerobic microbes; A mixing device for mixing the aerobic microorganisms fed from the aerobic microorganism food storage tank and the aerobic microorganisms supplied from the aerobic microorganism storage tank, separated from the moving gravity type solid-liquid separator and dried by the drying device, A microbial activation and sludge reduction device for activating the aerobic microorganisms mixed with sludge and aerobic microbial prey by ingesting microbial food and sludge oil, as well as a sludge reduction device, and a sludge reduction device for separating the supernatant from the sedimentation type solid- The Liquid separator for collecting the leachate separated from the liquid separator, wherein the sedimentation type solid-liquid separator comprises a solid-liquid separation tank constituted by an upper cylindrical portion and a lower conical portion, and connected to the excess sludge conveying pipe, Liquid separating tank, a crusher connected at the middle of the excess sludge inlet pipe for crushing the excess sludge, and a crusher connected to the bottom of the lower conus portion of the solid-liquid separation tank And a sludge discharge valve connected to an upper end of the upper cylindrical portion of the solid-liquid separation tank and extending downward to discharge a supernatant, and a sludge discharge valve for opening and closing the sludge discharge pipe, The present invention provides a sewage treatment system for sludge reduction.

According to the present invention, the excess sludge is extracted from the membrane-separation type activated sludge disposal apparatus, the water content in the excess sludge is reduced by the water content reduction means, and the pretreatment is performed by the excess sludge pretreatment tank to promote the solubility and biodegradability, It is possible to remarkably reduce the sludge throughput by drastically reducing the sludge throughput to the activated sludge disposal apparatus or to the anoxic tank, and also has the effect of increasing the nitrogen removal efficiency by supplying the additional carbon source necessary for nitrogen removal In addition, there is an effect of high efficiency.

1 is a schematic view of a wastewater treatment system for sludge reduction according to the sludge weight loss type membrane separation activated sludge process of the present invention,
2 is a view showing the sludge reducing means according to the present invention,
3 is a functional block diagram of control means for controlling the sludge reduction means,
4 is a schematic view of a sewage treatment method using a conventional membrane separation activated sludge process,
5 is a schematic view of a conventional sewage treatment method using a biological nitrogen and phosphorus removal type membrane separation activated sludge process.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Before describing the present invention, the following specific structural or functional descriptions are merely illustrative for the purpose of describing an embodiment according to the concept of the present invention, and embodiments according to the concept of the present invention may be embodied in various forms, And should not be construed as limited to the embodiments described herein.

In addition, since the embodiments according to the concept of the present invention can make various changes and have various forms, specific embodiments are illustrated in the drawings and described in detail herein. It should be understood, however, that it is not intended to limit the embodiments according to the concepts of the present invention to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

As shown in FIG. 1, the sewage treatment system for reducing sludge according to the present invention comprises a membrane separation type activated sludge treatment apparatus 10, an excess sludge pretreatment tank 20, and a coagulant dosage unit 30).

The membrane separation type activated sludge treatment apparatus 10 basically comprises an air supply device 11 for aerobic treatment of organic matter and a membrane solid-liquid separation device 12 using membrane separation, Or may be operated in a separate reaction tank.

When a denitrification step is included for the simultaneous removal of organic matter and nitrogen, a membrane separation aerobic tank (13) and an anoxic tank (15) are provided for interlocking through the internal circulation line (14) The nitrogen oxides are oxidized to nitrate nitrogen by the nitrifying microorganisms in the separation aerobic tank 13 and the nitrate nitrogen is sent to the anoxic tank 15 through the internal circulation line 14 where it is removed by denitrification.

At this time, an important requirement in the denitrification reaction other than the anoxic condition is a biodegradable carbon source. This is because the denitrifying microorganism is a microorganism that requires organic carbon as a food, unlike a nitrifying microorganism using inorganic carbon. Therefore, Is in the supply of the carbon source.

The excess sludge pretreatment tank 20 is connected to the membrane separation aerobic tank 13 through an excess sludge transport pipe 21 and to the anoxic tank 15 through a pretreatment sludge transport pipe 22. The surplus sludge return pipe (21) is provided with an excess sludge return pump (P).

In the surplus sludge pretreatment tank 20, the cell wall of the microorganisms constituting the sludge is chemically or mechanically destroyed to solubilize the microorganisms, and the polymer material is converted into a low molecular substance to increase the biodegradability of the sludge. Sludge pretreatment for sludge treatment is selected by alkali treatment, thermal treatment, ball mill treatment, ozone treatment, or selective treatment during the treatment.

The alkali treatment is performed at a pH of 10 to 14 for 2 to 4 hours, the thermal treatment is performed at 50 to 70 ° C for 2 to 4 hours, the ball mill treatment is performed at 2000 to 4000 rpm for 10 to 30 minutes, the ozone treatment is performed at 0.03 to 0.07 g O 3 / g-SS. The alkali treatment and the thermal treatment destroy the cell wall by promoting the hydrolysis of the cell wall, and the ball mill treatment destroys the cell wall by applying mechanical pressure.

In the present invention, when the membrane-separated activated sludge does not contain an anoxic tank, a sludge as much as a necessary amount for pretreatment is drawn out in the membrane separation aeration tank 13, and the pre-treated sludge is returned to the membrane separation aquarium 13, The sludge is circulated to the anoxic tank 15 through the inner circulation line 14 and then transferred to the membrane separation aeration tank 13 after the pre- To be processed.

The solubility and biodegradation efficiency of the wastewater sludge by the pretreatment were as shown in Table 1 below. The initial suspended solids concentration and COD (cr) concentration of sludge were 11,440 mg / L and 13,890 mg / L, respectively. Biodegradation experiments were carried out using Respirometry.

[Table 1]

(Solubilization and Biodegradation of Sludge by Chemical and Mechanical Pretreatment of Sludge)

In the pretreatment step shown in Table 1, the alkali treatment is relatively simple, low-cost treatment, and can be combined with other pretreatment processes and is easy, and when combined with thermal treatment or ozone treatment, the biodegradation efficiency .

The sludge having increased biodegradability through the pretreatment process is circulated to the reaction tank of the membrane separation type activated sludge treatment step and treated together with the biodegradable organic matter of the raw wastewater. However, if the anoxic tank is transported to the anoxic tank for nitrogen removal, It acts as a necessary carbon source to increase the denitration efficiency and increase the nitrogen removal rate.

In the case of inducing the decomposition of organic substances in the sludge through the pretreatment of excess sludge without the separate sludge drawing and the transfer of the pretreatment sludge, some of the organic substances in the sludge, which can not be decomposed biologically, are dissolved as ionic substances, The treated water and the discharged particulate inorganic material are accumulated in the reaction tank.

Therefore, in order to keep the concentration of microorganisms in the activated sludge constant, a minimum sludge drawing is required.

The amount of sludge to prevent accumulation of minerals is reduced to less than 10% when compared with the case without sludge pretreatment.

As a result, by applying the present invention, the amount of excess sludge generated can be reduced by 80 to 90% or more by installing a sludge pretreatment facility having a scale of about 0.5 to 1% of the amount of wastewater.

In the coagulant dosing device 30 for simultaneous removal of phosphorous (P), when the sludge generation amount is reduced through the membrane separation type activated sludge treatment device 10 and the surplus sludge pretreatment reaction tank 20, In order to solve this problem, in the present invention, a flocculant is administered. In this case, the flocculant is injected into the membrane separation aerobic tank in order to solve this problem. In this case, the removal of phosphorus in the biological treatment process is performed through the synthesis of phosphorous to sludge and the extraction of excess sludge. The sedimentation tank and the sediment retention time are not required, and since the sludge drawing amount is small, a considerable amount of the flocculant circulates in the treatment system, so that the amount of the flocculant can be reduced, and the treatment efficiency can be increased to 80 ~ 90% .

Further, the present invention can further reduce the water content of excess sludge installed in parallel with the excess sludge pretreatment reaction tank 20 in the excess sludge transport pipe 21 and the pretreatment sludge transport pipe 22, (MCD). ≪ / RTI >

The moisture content reducing means (MCD) is installed in series with the excess sludge preprocessing tank 20 in the excess sludge transport pipe 21. That is, the moisture content reduction means 100 is connected to the surplus sludge transport pipe 21 at the front end of the surplus sludge pretreatment tank 20.

The moisture content reducing means (MCD) comprises a sedimentation type solid-liquid separation device (100) for separating moisture from excess sludge introduced from the excess sludge return pipe (21), and a sludge separation device (200) for separating moisture from the sludge sludge while being conveyed, a drying device (300) installed on the upper part of the moving gravity type solid-liquid separator (200) for drying the sludge conveyed, A blowing drying device 400 installed at the upper end of the separating device 200 to dry the sludge by hot air, an aerobic microorganism tank 500 storing the aerobic microorganisms, a microorganism storage device for storing the microorganism food for feeding the aerobic microorganisms A sludge sludge separated from the moving gravity type solid-liquid separation device (200) and dried by the drying device (300) and the aerobic microorganism storage tank A mixing device 700 for mixing the aerobic microorganisms supplied from the aerobic microorganism food storage tank 600 and the aerobic microorganism feed supplied from the aerobic microorganism food storage tank 600 and the aerobic microorganisms fed from the aerobic microorganism feeding tank 600 mixed with sludge and aerobic microorganism food A microbial activation and sludge reduction device 800 that activates the microbes by consuming microbial food and sludge oil while reducing the amount of sludge, and a microbial activation and sludge reduction device 800, And a water collecting tank 900 for collecting and transferring the separated leachate to a reprocessing facility (not shown).

The sedimentation type solid-liquid separation apparatus 100 includes a solid-liquid separation tank 110 composed of an upper cylindrical portion 111 and a lower conical portion 112 and a solid-liquid separating tank 110 connected to the surplus sludge conveying pipe 21, An excess sludge inlet pipe 120 extending toward the inner upper end of the solid-liquid separation tank 110 through a lower end of the excess sludge inlet pipe 120 and a crusher 130 connected to the excess sludge inlet pipe 120 to break excess sludge, A sludge discharge pipe 140 connected to a lower end of the lower conical portion 112 of the solid-liquid separation tank 110 and discharging sludge extending downward, a sludge discharge pipe 140 connected to the upper end of the upper cylindrical portion 111 of the solid- And a sludge discharge valve (V) for opening and closing the sludge discharge pipe (140).

The crusher 130 crushes the excess sludge to effectively separate moisture from the sludge later. The crusher 130 may be configured to crush the excess sludge while rotating in a rotary form.

The moving gravity type solid-liquid separator 200 includes a belt conveyor 210 for conveying the sludge and a leachate storage tray 220 for receiving and storing the leachate separated from the sludge in the belt conveyor 210.

Although the moving gravity type solid-liquid separator 200 can be installed in one stage, it is preferable to install it in a plurality of stages (three stages in the drawing).

The belt conveyor 210 is preferably installed so as to be inclined upward by 5 to 10% toward the conveying direction so that the sludge is conveyed upward and the leached water separated from the sludge flows downward.

The sludge conveyed to the conveying direction of the belt conveyor 210 constituting the moving gravity type solid-liquid separator 200 is separated from the belt conveyor 210 and the belt conveyor 210 or the mixing device 600 A guide and a guide shoe 230 for guiding the guide shoe 230 accurately.

A leachate discharge pipe 240 is connected to the leachate storage tray 220.

The drying apparatus 300 may include a magnetron that oscillates microwaves and evaporates moisture contained in the sludge transferred by the belt conveyor 210 constituting the moving gravity type solid-liquid separator 200 to dry.

The magnetron constituting the drying apparatus 300 generates microwaves to generate heat by vibrating the moisture contained in the respective particles of the sludge, and drying the water by decreasing the water content by the heat.

Although the drying apparatus 300 may be installed in one stage, it is preferable to configure the drying apparatus 300 in a plurality of stages (three stages in the drawing) in order to increase the efficiency.

The drying apparatus 300 may be configured such that the water content of the sludge is about 50 to 66% at the first stage, 45 to 50% at the second stage, and about 30 to 45% at the third stage.

It is preferable that the drying apparatus 300 is provided with a closed chamber on the upper side of the belt conveyor 210 except the vent hole and is installed in the chamber.

The blast drying apparatus 400 is solid-liquid separated from the moving gravity type solid-liquid separation apparatus 200, and blows hot air to the sludge dried by the drying apparatus 300 to dry the sludge by heat and wind.

The water content of the final sludge can be lowered to 25 to 30% while the excess sludge passes through the sedimentation type solid-liquid separation device 100, the moving gravity type solid-liquid separation device 200, the drying device 300 and the air blow drying device 400 .

The aerobic microorganism tank 500 stores aerobic microorganisms of the same kind as the aerobic microorganisms in the membrane separation aeration tank 13.

The microbial food storage tank 600 stores food fed by the aerobic microorganisms, and corn powder may be used as the microbial food.

The mixing device 700 includes a mixing tank 710 into which sludge, aerobic microorganisms and microbial food are fed, an agitator 720 installed in the mixing tank 710 and mixing the sludge with aerobic microorganisms and microbial food, .

The mixing device 700 mixes the sludge, the aerobic microorganisms, and the microbial food evenly so that the aerobic microorganism can provide an environment in which the microbial food and the sludge can ingest the oil.

The microbial activation and sludge reduction device 800 activates aerobic microorganisms while consuming microbial food and sludge mixed in the mixing device 800, and reduces sludge.

The water collecting vessel 900 collects the supernatant separated from the sedimentation type solid-liquid separator 100 and the separated leachate from the moving gravity type solid-liquid separator 200. The supernatant collected in the collecting vessel 900 and the leachate And transferred to a sludge reprocessing facility (not shown) for reprocessing.

The water collecting tank 900 is connected to the supersonic water discharge pipe 150 through a collecting pipe 910 and the leachate discharge pipe 240 of the mobile gravity type solid-liquid separating device 200 is connected to the collecting pipe 910.

When the mobile gravity type solid-liquid separator 200 is constituted by a plurality of stages, the leachate discharge pipe 240 of each mobile gravity type solid-liquid separator 200 is connected to the collector pipe 910 in parallel.

It is preferable that the ratio of the sludge fed into the mixing device 800 to the aerobic microorganisms and the microbial food is maintained at a volume ratio of 1: 0.01: 1.

When the water content reduction means (MCD) is used, the efficiency is rapidly improved because the sludge weight reduction is maintained at about 85% or more.

The aerobic microorganisms activated in the microbial activation and sludge abatement apparatus 900, which is the final stage of the moisture content reduction means (MCD) described above, and the remaining sludge and microbial feed are supplied to the pretreatment reactor 20 for excess sludge.

Therefore, the excess sludge pretreatment tank 20 can be operated stably and efficiently since the water content is reduced and the total amount of sludge is reduced.

The waste water treatment system for reducing the sludge according to the present invention may further include the excess sludge return pump P, the sludge discharge valve V, the belt conveyor 210, the drying device 300, the air blow drying device 400, (1000) for controlling the control unit (1000).

The control unit 1000 includes an excess sludge detection sensor 1010 installed in the membrane separation and aeration tank 13, a conveyance sludge detection sensor 1020 installed at an upper portion of the solid-liquid separation tank 110 to detect a conveyance sludge, ,

A controller 1030 for outputting an excess sludge return pump driving command, a sludge discharge valve driving command, a conveyor driving command, a drying device driving command, a blow drying device driving command, and a stirrer driving command in response to a detection signal of the surplus sludge detection sensor 1010 A surplus sludge return pump driving unit 1040 for outputting a driving signal of the surplus sludge return pump P in accordance with an output command of the control unit 1030, A belt driving unit 1060 for outputting a driving signal of the belt conveyor 210, a drying device driving unit 1070 for outputting a driving signal of the drying device 300, And a stirrer driving unit 1090 for outputting a driving signal of the agitator 720. The agitator driving unit 1090 includes a driving unit 1080,

The operation of the moisture content reduction means (MCD) described above is performed by the control means 1000 in a batch manner.

That is, when the content of the sludge in the membrane separation aeration tank 13 sensed by the surplus sludge detection sensor 1010 increases beyond a set value, the control unit 1030 outputs an excessive sludge return pump drive command, The driving unit 1040 outputs the driving signal of the excess sludge return pump, whereby the excess sludge return pump P is operated to convey excess sludge through the excess sludge return pipe 21.

The control unit 1030 outputs a sludge discharge valve stop command, a conveyor stop command, a drying apparatus stop command, a blow drying apparatus stop command, and a stirrer stop command, and the sludge discharge valve driving unit 1050, the belt conveyor driving unit 1060, The drying apparatus driving unit 1070, the air drying and drying apparatus driving unit 1080 and the stirrer driving unit 1090 respectively output a sludge discharge valve closing signal, a belt conveyor stop signal, a drying apparatus stop signal, a blow dryer stop signal, The sludge discharge valve V is kept closed and the belt conveyor 210, the drying apparatus 300, the air drying apparatus 400 and the agitator 720 are kept stationary.

The surplus sludge conveyed through the surplus sludge transport pipe 21 and the surplus sludge inflow pipe 120 connected to the surplus sludge transport pipe 21 flows into the solid-liquid separation tank 110 from the upper end of the surplus sludge inflow pipe 120 to be filled therein.

When the solid-liquid separation tank 110 is filled with excess sludge, the control unit 1030 outputs a stop command for the excess sludge return pump P in accordance with the detection signal of the conveyance sludge detection sensor 1020, The excess sludge return pump 1040 outputs a stop signal of the excess sludge return pump P so that the operation of the excess sludge return pump P is stopped and no more surplus sludge is conveyed.

The excess sludge that has flowed into the solid-liquid separation tank 110 is settled by the sedimentation action so that the sludge is precipitated in the lower portion of the solid-liquid separation tank 110 and the moisture in the excess sludge becomes equal to the upper portion.

On the other hand, the control unit 1030 sets the time required for the sludge to sufficiently settle and distinguish the sludge from the sludge in a state in which the single surplus sludge is filled in the solid-liquid separation tank 110.

Accordingly, when the set time has elapsed, the control unit 1030 outputs a sludge discharge valve opening command, and the sludge discharge valve driving unit 1050 outputs a sludge discharge valve opening signal to open the sludge discharge valve V, The sludge settled in the separation tank (110) is discharged through the sludge discharge pipe (140).

At this time, the supernatant of the solid-liquid separation tank 110 is discharged through the supersonic water discharge pipe 150.

The sludge discharged from the sludge discharge pipe 140 is supplied to the belt conveyor 210 of the moving gravity type solid-liquid separator 200. In the course of being conveyed by the belt conveyor 210, water is leached from the sludge, And is stored in a leachate storage tray 220 provided below the conveyor 210.

The leached water stored in the leachate storage tray 220 is discharged through the leachate discharge pipe 240.

The sludge conveyed by the belt conveyor 210 is scraped by the scraper and guide chute 230 at the conveying end of the belt conveyor 210 and separated from the belt conveyor 210, .

The drying operation of the sludge finally takes place due to the hot wind blown from the air blow drying apparatus 400. The drying operation of the sludge finally reaches the conveying end of the belt conveyor 210 at the final stage.

The sludge finally dried by the air drying apparatus 400 is supplied to the mixing tank 710 of the mixing apparatus 700.

At this time, the aerobic microorganisms stored in the aerobic microorganism storage tank 500 and the microbial food stored in the microbial food storage tank 600 are put in the mixing apparatus 700 together and stirred by the stirrer 720.

In the mixing device 700, the mixed sludge and the aerobic microorganisms and the microorganisms fed into the microorganism activation and sludge abatement apparatus 800 are activated. Here, the aerobic microorganisms are activated while consuming the microbial food and at the same time the oil in the sludge is consumed, .

Finally, the reduced sludge of the sludge, the remaining microbial food and the aerobic microorganism are transferred to the surplus sludge pretreatment tank 20, and the sludge is once again reduced by the surplus sludge pretreatment tank 20.

When the sludge separated from the solid-liquid separation tank 110 of the sedimentation type solid-liquid separator 100 and the supernatant are all discharged, the above-mentioned operation is repeated again.

Therefore, according to the present invention, it is possible to sufficiently reduce the amount of sludge generated in the sewage treatment system.

Although it has been described in the above that the sludge reduction operation is performed according to the detection signal of the surplus sludge detection sensor 1010, it is also possible to use a scheme in which the surplus sludge detection sensor 1010 is not used, The above-described sludge reduction operation may be performed every cycle.

The supernatant discharged through the supernatant discharge pipe 150 and the leachate discharged from the leachate discharge pipe 240 of the mobile gravity type solid-liquid separator 200 are collected in the collecting tank 900 through the collecting pipe 910. The supernatant and leachate collected in the water collecting tank 900 are transferred to the reprocessing facility for reprocessing.

10: membrane separation type activated sludge treatment device 11: air supply device
12: Membrane solid-liquid separation device 13: Membrane separation aerobic tank
14: internal circulation line 15: anoxic tank
20: Surplus sludge pretreatment tank 21: Surplus sludge return tank
22: pretreatment sludge conveying pipe 30: coagulant dosing device
MCD: water content reducing means 100: sedimentation type solid-liquid separating apparatus
200: Moving gravity type solid-liquid separator 300: Drying device
400: air drying device 500: aerobic microorganism storage tank
600: microorganism food storage tank 700: mixing device
800: Microorganism activation and sludge reduction device 900: Sink tank

Claims (1)

(10), a surplus sludge pretreatment tank (20), and a flocculant (10) for treating wastewater by using a membrane separation type water treatment method in which a separation membrane is immersed in a membrane separation aeration tank by solid- And an administration device 30. The withdrawal sludge is added to the excess sludge pretreatment tank 20 to increase the solubility and biodegradability of the sludge by adding alkali chemicals to the anoxic tank 15 and the membrane separation aquarium 13 Thereby selectively accelerating the biodegradation and the ensemble of organic matter in the sludge and reducing the amount of sludge generated; The sludge is heated to alkali during the alkali treatment to accelerate and increase the solubility and biodegradability of the sludge or to reduce the sludge so as to promote and increase the solubility and biodegradability of the sludge by ball milling treatment after alkali treatment of the drawn sludge The sewage treatment system comprising:
The surplus sludge pretreatment tank 20 is connected to a membrane separation aerobic tank 13 and an anoxic tank 15 through an excess sludge conveyance pipe 21 and a pretreatment sludge conveyance pipe 22 and is connected to the surplus sludge conveyance pipe 21, An excess sludge return pump P is provided,
The coagulant dosing device 30 reduces the amount of sludge generated through the membrane separation type activated sludge treatment device 10 and the surplus sludge pretreatment reaction tank 20 and the removal of phosphorus in the biological treatment process results in the synthesis of phosphorus in sludge, When the removal efficiency of the phosphorous in the raw water is lowered due to the drawing, the flocculant is supplied to the membrane separation aeration tank (13) so that the sedimentation tank or the sedimentation retention time need not to be provided. In addition, So that the amount of coagulant can be reduced,
The surplus sludge conveying pipe 21 is provided in the excess sludge conveying pipe 21 so as to increase the treatment efficiency by lowering the water content of the sludge before the pretreatment reaction of the surplus sludge pretreatment tank 20, Further comprising a water content reducing means (MCD) connected in series with the excess sludge pretreatment tank (20) at the front end of the excess sludge pretreatment tank (20)
The moisture content reducing means (MCD) comprises a sedimentation type solid-liquid separation device (100) for separating moisture from excess sludge introduced from the excess sludge return pipe (21), and a sludge separation device A moving gravity type solid-liquid separating apparatus 200 for separating moisture from the sludge sludge while being transferred, a drying apparatus 300 installed on the moving gravity type solid-liquid separating apparatus 200 for drying the sludge conveyed by microwaves, A blowing and drying unit 400 installed on the final stage of the mobile gravity-type solid-liquid separator 200 to dry the sludge by hot air, an aerobic microorganism tank 500 storing the aerobic microorganisms, microorganisms feeding the aerobic microorganisms A sludge drier 300 separated from the moving gravity type solid-liquid separator 200, A mixing device 700 for mixing the aerobic microorganisms supplied from the established microorganism storage tank 500 and the aerobic microbial food supplied from the aerobic microorganism food storage tank 600 and the sludge and aerobic microbial food A microbial activation and sludge reduction device 800 that activates the aerobic microorganisms mixed with the microbial food and the sludge while consuming the microbial food and sludge oil and reduces the sludge, And a water collecting tank (900) for collecting the separated leachate from the solid-liquid separator (200)
The sedimentation type solid-liquid separation apparatus 100 includes a solid-liquid separation tank 110 composed of an upper cylindrical portion 111 and a lower conical portion 112 and a solid-liquid separating tank 110 connected to the surplus sludge conveying pipe 21, An excess sludge inlet pipe 120 extending toward the inner upper end of the solid-liquid separation tank 110 through a lower end of the excess sludge inlet pipe 120 and a crusher 130 connected to the excess sludge inlet pipe 120 to break excess sludge, A sludge discharge pipe 140 connected to a lower end of the lower conical portion 112 of the solid-liquid separation tank 110 and discharging sludge extending downward, a sludge discharge pipe 140 connected to the upper end of the upper cylindrical portion 111 of the solid- And a sludge discharge valve (V) for opening and closing the sludge discharge pipe (140). The sludge discharge valve (150)
The moving gravity type solid-liquid separator 200 includes a plurality of stages of belt conveyors 210 for conveying sludge and a leachate storage tray 220 for receiving and storing leachate separated from the sludge in the belt conveyor 210. And the belt conveyor 210 is installed so as to be inclined upward by 5 to 10% toward the conveying direction so that the sludge is conveyed upward and the leachate separated from the sludge flows downward. In the conveying direction of the belt conveyor 210 A scraper and guide chute 230 for separating the sludge conveyed from the belt conveyor 210 and guiding the conveyed sludge accurately to the belt conveyor 210 or the mixing device 600 at the next stage, And a leachate discharge pipe 240 connected to the leachate discharge pipe 240,
The mixing device 700 includes a mixing tank 710 into which sludge, aerobic microorganisms and microbial food are fed, an agitator 720 installed in the mixing tank 710 and mixing the sludge with aerobic microorganisms and microbial food, And,
The water collecting tank 900 collects the supernatant separated from the sedimentation type solid-liquid separator 100 and the separated leachate from the moving gravity type solid-liquid separator 200 and transfers the collected supernatant and leachate to the sludge reprocessing facility ≪ / RTI >
Further includes control means 1000 for controlling the excess sludge conveying pump P, the sludge discharge valve V, the belt conveyor 210, the drying device 300, the air blow drying device 400 and the agitator 720 In addition,
The control unit 1000 includes an excess sludge detection sensor 1010 installed in the membrane separation and aquarium basin 13 for detecting the content of sludge and a control unit 1010 for detecting the content of the conveying sludge, A sludge discharging command, a conveyor driving command, a drying device driving command, a blow drying device driving command, a stirring device driving command, and an agitator driving command, in response to a sensing signal of the surplus sludge sensing sensor 1010, A surplus sludge return pump driving unit 1040 for outputting a driving signal of the surplus sludge return pump P in accordance with an output command of the control unit 1030, a sludge discharge valve V A belt conveyor driving unit 1060 for outputting a driving signal of the belt conveyor 210, a driving signal generator 1060 for outputting a driving signal of the drying apparatus 300, And a stirrer driving unit 1090 for outputting a driving signal of the agitator 720. The agitator driving unit 1070 includes a drying device driving unit 1070, a drying device driving unit 1080 for outputting a driving signal of the air drying device 400, Wherein the controller is configured to control the operation of the moisture content reducing means (MCD) in a batch manner.

Images