KR20170116592A - sludge concentrating and dehydrating system in Wastewater treatment process and and method of maintaining performance the same - Google Patents

Abstract

The present invention relates to a sludge thickening and dewatering system for a wastewater treatment process capable of more effectively stabilizing sludge generated in a wastewater treatment process and concentrating and dehydrating the same, and a performance maintenance method thereof.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sludge concentrating and dewatering system for wastewater treatment, and a sludge concentrating and dehydrating system in a wastewater treatment process,

More particularly, the present invention relates to a sludge thickening and dewatering system for a wastewater treatment process capable of more effectively stabilizing sludge generated in a wastewater treatment process and concentrating and dewatering the same, will be.

If the wastewater is discharged without treatment, the wastewater can be destroyed or the human health can be damaged. Since the wastewater is separated from the wastewater through the various treatment processes before discharge, the wastewater can be appropriately managed without deteriorating the hygiene of the water system Only treated water that meets water quality standards is discharged to rivers and oceans.

The wastewater treatment process is divided into biological treatment such as screening, floatation, filtration, physical treatment of sedimentation, chemical treatment such as neutralization, oxidation, reduction, flocculation, ion exchange and aerobic treatment or anaerobic treatment .

These unit processes are connected to constitute a whole wastewater treatment process. Fig. 1 shows a general wastewater treatment process.

The wastewater introduced as inflow water flows into the first settling tank 20 after the sand or gravel is removed from the grit chamber (not shown).

In the primary sedimentation tank 20, precipitated solid particles (SS) in the wastewater are precipitated and removed together with the organic material (BOD, biochemical oxygen demand). That is, BOD and SS are removed together.

The separated sludge is discharged separately as a primary sludge or introduced into a concentrating section 50 described later. The inflow water from which the sludge has been separated enters the reaction tank 10 and is subjected to biological treatment.

The reaction tank 10 is provided with an air supply means such as a compressor 15 connected to the reaction tank 10 so that organic substances not removed from the primary settling tank 20 are synthesized into energy sources and cells in the metabolic activity process of microorganisms in the reaction tank 10. [ Thereby forming a floc.

The inflow water treated in the reaction tank 10 flows into the secondary sedimentation tank 30. In the second settling tank 30, the flocculant is precipitated and solid-liquid separated to discharge treated water to the top of the process, and the secondary sludge is taken out to the concentrating unit 50 connected thereto.

The separated sludge is introduced into the concentrating part 50 and allowed to stand for several hours (for example, 8 to 20 hours) so that solid-liquid separation is performed by gravity sedimentation. When the supernatant is taken out, the concentration of the sludge is increased and concentrated.

The concentrated sludge is conveyed to the dehydrator 70. The dehydrator 70 can be configured in various ways such as a vacuum filter, a filter press, a belt press, etc., so that the volume of the sludge is reduced, The effluent produced in this process is transferred to the top of the process.

The dehydrator 70 may be provided with a medicine supply part 75 for supplying a medicine such as a flocculant for increasing dehydration efficiency.

Since the dehydrator 70 requires a great deal of resources such as power and chemicals, the dehydrator 70 needs to increase its efficiency. Therefore, in most wastewater treatment processes currently in operation, It is only about 8 hours.

In other words, in the current wastewater treatment process, since the wastewater is generated continuously for 24 hours and flows into the wastewater treatment process, the capacity of the concentration unit 50 can be about three times as much as the treatment capacity of the dehydrator 70 And the dehydrator 70 is operated only for about 8 hours per day.

That is, on the side of the concentrating section 50, the valve V is opened in the concentrating section 50 for about eight hours per day when the dehydrator 70 is operated, and the pump P is operated to discharge the concentrated sludge to the dehydrator 70 The pump V is closed for about 16 hours a day when the dehydrator 70 is not operated and the pump P is stopped so that the sludge introduced from the secondary settling tank 30 is continuously stored. to be.

On the other hand, Patent Literatures 1 to 4 disclose apparatuses and methods for composting sludge, but they also disclose an apparatus or method for efficient fermentation of sludge discharged therefrom, and the sludge generated in the wastewater treatment process There is still a problem that it must be reused through additional facilities.

2015-0085494A 2013-0010952A 2012-0105628A 2007-0047893A

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a sewage treatment plant, The sludge can not be simply stored but merely sludge can be assimilated to reduce the amount of the sludge to be carried out to the outside, to reduce the odor of the sludge, to increase the dewatering efficiency, A sludge concentration and dewatering system in a new wastewater treatment process capable of reducing the amount of chemicals contained and a method for maintaining performance thereof.

A primary settling tank 200 in which suspended solids contained in the inflowed sewage are settled as primary sludge, a reaction tank 100 in which inflow water in the primary settling tank 200 is received and treated by microorganisms, The sludge concentration tank 500B into which the secondary sludge settled in the secondary settling tank 300 flows, and the sludge concentration tank 500B in which the secondary sludge settled in the secondary settling tank 300 is introduced, in the wastewater treatment process including the treated water and the secondary settling tank 300 in which the treated water is separated into the treated water and the secondary sludge, ; A dehydrator 700 into which the concentrated secondary sludge is introduced and dehydrated in the sludge concentration tank 500B; A cleaning bath 800 connected to the fine bubble supplying unit 400; A pump (P) and a sludge valve (V2) at the downstream of the pump (P), respectively, provided in the dehydrating line into which the secondary sludge is introduced into the dehydrator (700) in the sludge thickening tank (500B); An air valve (V1) provided in a recirculation line to the sludge concentration tank (500B) by the pump (P) as a line branched from the dehydration line; And a fine bubble supplying unit (400) provided at a rear end of the air valve (V1) and introducing the secondary sludge stored in the sludge concentration tank into the fine bubble supplying unit (400). During a predetermined first time, The valve V1 is opened and the sludge valve V2 is closed so that the secondary sludge stored in the sludge concentration tank 500B which is the front end of the dehydrator 700 passes through the fine bubble supplying unit 400, The air valve V1 is closed and the sludge valve V2 is closed for a predetermined second time period by supplying the microbubbles to the sludge thickener 500B again, The secondary sludge stored in the sludge concentration tank 500B and containing fine bubbles is introduced into the dehydrator 700 and discharged after being dewatered, The second sludge is supplied to the dehydrator 700 when the concentration of the secondary sludge stored in the sludge concentration tank 500B is higher than a preset concentration, The first and second times are continuously and alternately progressed while the fine bubble supplying unit 400 is operated in a continuous and alternating manner. In this case, the dehydrating agent in the fine bubble supplying unit 400 is injected into the sludge thickening tank 500B to reduce the load of the dehydrator 700, The dehydrator 700 continues to operate only during the first time and the dehydrator 700 continues to operate only during the second time, thereby providing a sludge thickening and dewatering system.

The fine bubble supplying unit 400 includes an inlet 410 provided at one side of the sludge concentration tank 500B and through which the washing liquid flows from the secondary sludge or the washing tub 800; A mixing portion 420 extending from the inlet 410; An air inlet 430 provided at one side of the mixing part 420 and through which the air flows; An air distribution unit 440 branched from the air inlet 430 and communicating with the mixing unit 420; And an outlet port 450 extending from the mixing section 420. The secondary sludge is introduced into the inlet 410 through the air inlet 430 and the air distributor 440, Air is mixed in the mixing part 420 and a swirl flow is generated and supplied to the sludge concentration tank 500B through the outlet 450. [

When the water quality and flow rate of the influent water or the water quality and flow rate of the secondary sludge flowing into the sludge thickening tank 500B is greater than or less than a preset range, the fine bubble supplying unit 400 may supply the sludge to the sludge thickening tank 500B The air supply is stopped and the cleaning liquid is supplied from the cleaning tank 800 to the fine bubble supplying unit 400 so that the supply of the fine bubbles to the sludge thickening tank 500B from the fine bubble supplying unit 400, It is preferable that the supply of the cleaning liquid from the micro bubble supplying unit 400 to the micro bubble supplying unit 400 is performed at the time of dewatering the secondary sludge.

The cleaning liquid supplied to the fine bubble supplying unit 400 is preferably supplied by gravity.

The present invention also provides a method for maintaining the performance of a sludge concentration and dewatering system in the sewage treatment process, comprising the steps of: (a) depositing suspended solids contained in sewage water flowing into the primary settling tank 200 into the primary sludge; A step (S100) in which the separated sewage water settled in the tea settling tank (200) flows into the reaction tank (100), treated by microorganisms, and separated into treated water and the secondary sludge; (b) the deposited secondary sludge is introduced into the sludge thickening tank 500B and stored (S200); (c) During the first predetermined time, the air valve (V1) is opened and the sludge valve (V2) is closed, so that the stored secondary sludge flows into the minute bubble supplying part (400) (S300) in which the sludge is supplied to the sludge concentration tank (500B) and stored again. (d) During the second predetermined time, the air valve (V1) is closed and the sludge valve (V2) is opened, whereby the secondary sludge stored in the sludge concentration tank (500B) A step S400 of flowing into the dehydrator 700, dewatering and discharging to the outside; And (e) determining whether the water quality and flow rate of the inflow water to be introduced or the water quality and flow rate of the secondary sludge flowing into the sludge concentration tank 500B exceeds or falls below a predetermined range (S500); (f) If the water quality and the flow rate of the inflow water or the water quality and the flow rate of the secondary sludge flowing into the sludge thickening tank 500B are more than or less than the predetermined range, And a step (S600) of stopping supply of air to the fine bubble supplying unit (400) from the cleaning tank (800) and stopping air supply to the fine bubble supplying unit .

The air bubbles in the secondary sludge may be stopped by the micro bubble supplying unit 400 at a predetermined interval in place of the steps (e) and (f) And supplying the cleaning liquid from the cleaning tank 800 to the fine bubble supplying unit 400 (S600).

The supply of the cleaning liquid from the cleaning tank 800 to the fine bubble supplying unit 400 to the fine bubble supplying unit 400 can be stopped by stopping the air introduction into the secondary sludge from the fine bubble supplying unit 400, Is performed during the execution of the step.

In the step (c), the secondary sludge stored in the sludge concentration tank 500B flows into the micro-bubble supplying unit 400 and the micro-bubbles are introduced into the sludge concentration tank (D) after the predetermined first time, the secondary sludge stored for a predetermined second time is supplied to the dehydrator (500) 700, and dehydrating the sludge concentration tank 500B, the secondary sludge stored in the sludge concentration tank 500B is introduced into the fine bubble supplying unit 400 and the fine bubbles are mixed and continuously supplied to the sludge thickening tank 500B S400).

As described above, according to the present invention, by supplying fine bubbles to the secondary sludge introduced and stored in the thickening section to aerate them, it is possible to reduce odor according to the stabilization of nitrogen contained in the secondary sludge, And coagulant use amount are reduced, and stabilized nitrogen is contained in discharged sludge. Therefore, there is an advantage that commercial use such as compost is easy without additional post-treatment.

Also, through its performance maintenance method, the performance of the fine bubble supplying unit for supplying fine air can be maintained for a long period of time, thereby ensuring long-term stable operation of the entire system.

1 is a conceptual diagram for explaining a conventional wastewater treatment process.
2 is a conceptual diagram for explaining a sludge concentration and dewatering system in the wastewater treatment process according to the first embodiment of the present invention.
3 is a conceptual diagram for explaining a sludge concentration and dewatering system in a wastewater treatment process according to a second embodiment of the present invention.
4 is a conceptual diagram for explaining a sludge concentration and dewatering system in the wastewater treatment process according to the third embodiment of the present invention.
5 is a detailed cross-sectional view of the fine bubble supplying device.
6 is a flowchart of a method for maintaining and maintaining the performance of a sludge concentration and dewatering system in a wastewater treatment process according to the present invention.

These and other objects, features and other advantages of the present invention will become more apparent by describing in detail preferred embodiments of the present invention with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, the definitions of these terms should be described based on the contents throughout this specification.

In addition, the described embodiments are provided for illustrative purposes and do not limit the technical scope of the present invention.

The components constituting the sludge thickening and dewatering system of the wastewater treatment process according to the present invention can be used integrally or separately. In addition, some components may be omitted depending on the usage pattern.

Hereinafter, a sludge thickening and dewatering system (hereinafter simply referred to as "system") in the wastewater treatment process according to the present invention will be described with reference to FIGS. 2 to 5 attached hereto.

Figure 2 shows a system according to a first embodiment of the invention, Figure 3 shows a system according to a second embodiment of the invention, Figure 4 shows a system according to a third embodiment of the invention .

Hereinafter, in the first and second embodiments, the concentrating unit 500 is a sludge storage tank 500A. That is, the sludge is not mixed and solid-liquid separated. In the third embodiment, the thickening section 500 is the sludge thickening tank 500B. That is, the sludge is solid-liquid separated. Hereinafter, it is to be noted that the concentration unit 500 is not directly shown in FIG. 2 to FIG. 4 but is a name including both the sludge storage tank 500A and the sludge concentration tank 500B.

First, a system according to the first embodiment will be described with reference to Figs. 2 and 5. Fig.

2, the system according to the first embodiment of the present invention includes a reaction tank 100, a primary settling tank 200, a secondary settling tank 300, a sludge storage tank 500A as a concentration unit 500, A dehydrator 700, a fine bubble supplying unit 400, and a cleaning bath 800. [

The primary settling tank 200 is located between the inflow portion of the inflow water and the reaction tank 100. The first settling sludge is firstly precipitated in the contaminant contained in the influent water and the precipitated sludge is discharged as a primary sludge .

When the treated water having passed through the primary settling tank 200 flows into the reaction tank 100, some of the organic pollutants in the influent water is decomposed and taken up by the aerobic microorganisms in the reaction tank 100, and the remaining part is synthesized into microbial cells Out.

A compressor 150 connected to the reaction tank 100 is provided to supply air to the reaction tank 100 to assist the aerobic microorganisms in the reaction tank 100.

The secondary settling tank 300 is connected to the downstream end of the reaction tank 100, and discharges the treated water after precipitating the secondary sludge.

The sludge storage tank 500A is connected to the second settling tank 300, and the deposited secondary sludge in the second settling tank 300 is introduced and stored.

Although not shown, some of the secondary sludge discharged from the secondary settling tank 300 is partially returned to the outside of the reaction tank 100 to maintain the F / M ratio (Food-to-Microorganism ratio) It may be returned to the reaction tank 100 as sludge, and another part may flow into the sludge storage tank 500A and be concentrated.

The fine bubble supplying unit 400 is connected to the sludge storage tank 500A and generates fine bubbles to supply air to the sludge storage tank 500A.

By supplying air to the secondary sludge concentrated in the sludge storage tank 500A to aerate it, NH4 contained in the secondary sludge is converted into NO3 and stabilized.

Further, a part of the secondary sludge concentrated in the sludge storage tank 500A may be introduced into the fine bubble supplying unit 400, and the air may be mixed and supplied into the sludge storage tank 500A.

5, the detailed configuration of the fine bubble supplying unit 400 will be described in detail. The fine bubble supplying unit 400 includes an inlet 410, a mixing unit 420, an air inlet 430, (440) and an outlet (450).

The inlet 410 is located at one side of the fine bubble supplying part 400 and is connected to the concentration part 500 so that the secondary sludge is discharged from the concentration part 500 through the pump P Lt; / RTI >

The mixing portion 420 extends from the inlet 410 and flows into the secondary sludge introduced through the inlet 410.

The air inlet 430 is provided at one side of the mixing portion 420 and air to be supplied to the condensing portion 500 is introduced through the air inlet 430. The air introduced at this time is introduced at a high speed By the negative pressure generated inside the mixing portion 420 by the secondary sludge.

Alternatively, a compressor (not shown) for supplying air to the air inlet 430 may be separately provided, or air may be supplied from the compressor 150 connected to the reaction tank 100.

One end of the air distribution unit 440 is branched from the air inlet 430 and connected to the mixing unit 420 so that the air introduced into the air inlet 430 is distributed, The air flowing into the mixing section 420 is mixed with the secondary sludge passing through the mixing section 420 and the air is aerated to produce minute bubbles and the generated minute bubbles are mixed with the mixing section 420 And is supplied to the concentrating unit 500 while forming a swirling flow through the communicated outlet port 450.

The swirling flow is a flow generated by the flow in the axial direction and the flow in the circumferential direction about the axis when the fluid flows in the tangential direction of the cylindrical tube. The swirling flow flows through the inlet 410 and the secondary sludge The air introduced in the circumferential direction through the air inlet 430 and the air distributor 440 is mixed in the mixing part 420 to form a swirling flow and the air is finely separated to form minute bubbles, .

As the fine bubbles forming the swirling flow are supplied to the thickening section 500, the surface area of contact between the air and the secondary sludge becomes large, and the stabilization efficiency of NH4 contained in the secondary sludge becomes high.

Further, as described above, the secondary sludge passing through the mixing portion 420 can naturally intake air through the air inlet 430, so that no additional power is required to supply the air, It is possible to maintain an economical system because there is no energy consumption for supplying air to the air conditioner 500.

2, the dehydrator 700 is connected to the sludge storage tank 500A, and the secondary sludge (or secondary sludge containing fine bubbles) concentrated in the sludge storage tank 500A is discharged to the dehydrator 700 And the water contained in the introduced secondary sludge becomes a desorption liquid and is returned to the top of the process to the top of the process.

A medicine supplier 750 for supplying a coagulant such as a polymer to the dehydrator 700 may be connected so that dehydration and coagulation of the secondary sludge in the dehydrator 700 can be smoothly performed.

The secondary sludge dehydrated in the dehydrator 700 may be discharged in the form of a solid cake to be discarded or used as compost.

The cleaning tank 800 is connected to the fine bubble supplying unit 400, specifically, the inlet 410 of the fine bubble supplying unit 400 to supply the cleaning liquid for cleaning the fine bubble supplying unit 400, Can be supplied by gravity without using a separate pump or the like.

Hereinafter, a performance maintenance method of the sludge concentration and dewatering system in the wastewater treatment process according to each embodiment of the present invention will be described in detail with reference to FIG. 6 attached hereto.

First, the suspended solids contained in the inflow water flowing into the primary settling tank 200 are settled as primary sludge, the treated sludge is settled in the primary settling tank 200, and the separated treated water flows into the reaction tank 100, And the suspended solids contained in the treated water treated in the reaction tank 100 are precipitated as secondary sludge (S100).

That is, the inflow water flowing into the secondary settling tank 300 is separated into the secondary sludge and treated water.

Next, the precipitated secondary sludge is introduced into the concentration unit 500 and concentrated (S200).

The secondary sludge in the sludge storage tank 500A is branched by the operation of the valves V1 and V2 as shown in FIG. 2. In the first embodiment described, the secondary sludge is branched depending on whether the dehydrator 700 is operated or not.

Minute bubbles are supplied to the stored secondary sludge for a predetermined first time (S300).

Minute bubbles are supplied for a predetermined first time period during which the dehydrator 700 does not operate (for example, for the remaining 16 hours if the dehydrator 700 operates for eight hours a day, as described in the prior art).

That is, according to the prior art, the secondary sludge is stored in the thickening section 50 during the time when the dehydrator 70 does not operate (see FIG. 1), but in the present invention, fine bubbles are supplied during the time.

Specifically, during the first predetermined time, the valve V2 is closed, the valve V1 is opened, the pump P is continuously driven, and a part of the secondary sludge stored in the sludge storage tank 500A is sublimated into fine bubbles And then flows into the supply unit 400. The introduced secondary sludge is mixed with air, and the mixed secondary sludge and air are supplied to the sludge storage tank 500A, and the secondary sludge is aerated.

Here, the pump P providing power for injecting the minute bubbles is a conventional pump for transferring the secondary sludge to the dehydrator 700. Referring to FIG. 1, the existing facility is provided with a pump for transferring the secondary sludge to the dehydrator 70, which is used without modification.

The pump P also operates continuously for a second time period, which will be described later, for transferring the secondary sludge to the dewatering device 700, and continues to operate continuously. According to the prior art, since the pump P is operated only during the second time period when the dehydrator 70 is operated, there is a difference in the operation time.

The mixing amount of the secondary sludge and the air in the fine bubble supplying part 400 varies depending on the flow rate, temperature or DO value of the secondary sludge flowing into the thickening part 500, And may be provided on a line connecting the settling tank 300 and the sludge storage tank 500A.

Next, when the predetermined first time has elapsed, the secondary sludge is dehydrated for a predetermined second time (S400).

Specifically, during the second predetermined time, the valve V1 is closed, the valve V2 is opened, the pump P is continuously driven to be stored in the sludge storage tank 500A, and at the same time, The tea sludge is introduced into the dehydrator 700, and the water contained in the concentrated secondary sludge is dehydrated. At this time, the coagulant may be supplied to the dehydrator 700 from the medicine supply unit 750.

Here, steps S300 and S400 may be performed for each predetermined time, specifically, for the first time and the second time, as described above.

In general, the wastewater treatment system is operated on a daily basis. During the operation time of about 16 hours, the micro bubbles are supplied to the sludge storage tank 500A for a predetermined time, The second sludge is introduced into the dehydrator 700 for a predetermined period of time, and dehydration is performed. This can be achieved by controlling each valve and the pump described above.

Other embodiments of steps S300 and S400 will be described with reference to FIGS. 3 to 4. FIG.

The second embodiment will be described with reference to FIG. 3, focusing on the differences from the first embodiment.

Also in the second embodiment, the sludge storage tank 500A is used as the concentrated portion 500. [ Unlike in the first embodiment, the second sludge is not supplied to the fine bubble supplying unit 400, but the fine bubble supplying unit 400 directly supplies fine bubbles to the sludge storing tank 500A. In this case, a separate pump Pa is required.

Unlike the first embodiment, an expensive pump Pa is required, which is disadvantageous in terms of initial installation cost, but is advantageous in that the micro bubbles can be continuously supplied even while the dehydrator 700 is operated.

That is, in the first embodiment, the minute bubbles were supplied only during the first time when the dehydrator 700 was not operated, and the minute bubbles could not be supplied during the second time when the dehydrator 700 was operated. However, in the second embodiment The micro pores can be supplied to the sludge storage tank 500A by operating the pump Pa while the dehydrator 700 is operated.

Next, a third embodiment of the present invention will be described with reference to FIG.

Unlike the first and second embodiments, the concentrating unit 500 is not a sludge storage tank 500A but a sludge concentration tank 500B, where solid-liquid separation of the secondary sludge is performed. The liquid-liquid separated supernatant can be returned to the top of the process. In this case, since the moisture content of the sludge flowing into the dehydrator 700 is lowered, the load of the dehydrator 700 is lowered.

On the other hand, as in the first and second embodiments, only the sludge separated by solid-liquid separation flows into the dehydrator 700 during the second time. When the dehydrator 700 is operated, the dehydrated liquid, which is dehydrated water, is generated separately from the sludge to be carried out. In the first and second embodiments, the deodorant is transported to the top of the process. In the third embodiment, the valve V3 is operated And recovered in the sludge thickening tank 500B. When the desorption liquid is collected in the sludge concentration tank 500B, the concentration of the secondary sludge is excessively high, so that solid-liquid separation of the sludge concentration tank 500B is difficult, and in a special case where sludge is not smoothly conveyed from the sludge concentration tank 500B to the dehydrator 700 would.

Next, it is determined whether the water quality and the flow rate of the influent water or the water quality and the flow rate of the secondary sludge flowing into the concentrating unit 500 are both greater than or less than a preset range (S500). All of the above embodiments can be applied from this step.

The inflow water flowing through a sensor (not shown) provided on a line connecting the inflow section and the second settling tank 300 and the concentration section 500 and the sludge flowing into the concentration section 500 are detected .

Next, if the water quality and flow rate of the influent water or the water quality and the flow rate of the secondary sludge flowing into the thickening section 500 are greater than or less than a predetermined range, The cleaning liquid is supplied from the cleaning tank 800 to the fine bubble supplying unit 400 (S600).

The fine bubble supplying unit 400 is cleaned by the supplied cleaning liquid. At this time, only the cleaning liquid can be supplied to the fine bubble supplying unit 400 for cleaning, and the cleaning water and the air supplied from the compressor can be mixed, The rinsing of the fine bubble supplying unit 400 can be performed by flushing the supplying unit 400 or mixing the air and the removing liquid generated in the dehydrator 700. [

In addition, the cleaning of the fine air supply unit is not performed according to the water quality and the flow rate of the inflow water and the secondary sludge, but may be performed every predetermined cycle.

In general, the wastewater treatment system is operated on a daily basis. The micro bubbles are supplied to the concentration unit 500 during the corresponding time of about 16 hours as the first time, The second sludge is introduced into the dehydrator 700 for a predetermined period of time, and dehydration is performed. This can be achieved by controlling each valve and the pump described above.

That is, the steps S300 and S400 may be alternately performed for each predetermined time. In addition, the cleaning of the fine bubble supplying unit 400 in the step S600 is performed in the dehydrating process of the secondary sludge as the step S400 , The process can be efficiently operated (the first and third embodiments).

As described above, according to the sludge thickening and dewatering system in the wastewater treatment process according to the present invention, fine bubbles are supplied to the secondary sludge introduced into the thickening part 500 and aeration, thereby stabilizing nitrogen contained in the secondary sludge The deodorization efficiency and the amount of the flocculant to be used are reduced, and the stabilized nitrogen is contained in the discharged sludge, so that the commercial use such as composting is easy without any post-treatment There are advantages.

In addition, through the performance maintenance method, the performance of the fine bubble supplying unit 400 for supplying fine air can be maintained for a long period of time, thereby ensuring long-term stable operation of the entire system.

Although the preferred embodiments of the present invention have been described, the present invention is not limited to the specific embodiments described above. It will be apparent to those skilled in the art that numerous modifications and variations can be made in the present invention without departing from the spirit or scope of the appended claims. And equivalents should also be considered to be within the scope of the present invention.

100: Reactor
200: primary settling tank
300: secondary settling tank
400: fine bubble supplying unit
500: concentrated portion
700: Dehydrator
800: Washing machine

Claims (8)

A primary settling tank 200 in which suspended solids contained in the inflowed sewage are settled as primary sludge, a reaction tank 100 in which inflow water in the primary settling tank 200 is received and treated by microorganisms, In the wastewater treatment process including the second settling tank 300 in which treated influent water is separated into treated water and secondary sludge,
A sludge concentration tank 500B into which the secondary sludge settled in the secondary settling tank 300 flows;
A dehydrator 700 into which the concentrated secondary sludge is introduced and dehydrated in the sludge concentration tank 500B;
A cleaning bath 800 connected to the fine bubble supplying unit 400;
A pump (P) and a sludge valve (V2) at the downstream of the pump (P), respectively, provided in the dehydrating line into which the secondary sludge is introduced into the dehydrator (700) in the sludge thickening tank (500B);
An air valve (V1) provided in a recirculation line to the sludge concentration tank (500B) by the pump (P) as a line branched from the dehydration line; And
And a fine bubble supplying unit (400) provided at a rear end of the air valve (V1) for introducing the secondary sludge stored in the sludge concentration tank and mixing the fine bubbles,
During the first predetermined time, the air valve V1 is opened and the sludge valve V2 is closed, so that the secondary sludge stored in the sludge concentration tank 500B, which is the front end of the dehydrator 700, Is supplied again to the sludge thickener tank (500B) together with the micropellets which have passed through the supply unit (400) and are ready to be introduced into the dewatering tank (700)
During the second predetermined time, the air valve V1 is closed and the sludge valve V2 is opened so that the secondary sludge stored in the sludge concentration tank 500B and containing fine bubbles flows into the dehydrator 700 The dehydrator 700 operates during the second predetermined time period to dehydrate the secondary sludge supplied with the microbubbles and discharge the secondary sludge to the outside. The sludge is discharged to the sludge concentration tank 500B When the concentration of the secondary sludge is higher than a preset concentration, the desolvation solution in the dehydrator 700 is injected into the sludge concentration tank 500B to reduce the load of the dehydrator 700,
The first time and the second time are continuously and alternately advanced, the minute bubble supplying unit 400 continues to operate only during the first time, and the dehydrator 700 continues to operate only during the second time ,
Sludge Concentration and Dewatering System in Sewage Treatment Process.
The method according to claim 1,
The fine bubble supplying unit 400 includes:
An inlet 410 provided at one side of the sludge concentration tank 500B to receive the washing liquid from the secondary sludge or the washing tub 800;
A mixing portion 420 extending from the inlet 410;
An air inlet 430 provided at one side of the mixing part 420 and through which the air flows;
An air distribution unit 440 branched from the air inlet 430 and communicating with the mixing unit 420; And
And an outlet 450 extending from the mixing part 420,
The secondary sludge flowing into the inlet 410 and the air distributed through the air inlet 430 and the air distributor 440 are mixed in the mixing unit 420 to generate a swirling flow, 450 to the sludge thickening tank 500B,
Sludge Concentration and Dewatering System in Sewage Treatment Process.
3. The method of claim 2,
When the water quality and flow rate of the influent water or the water quality and flow rate of the secondary sludge flowing into the sludge thickening tank 500B is greater than or less than a preset range, the fine bubble supplying unit 400 may supply the sludge to the sludge thickening tank 500B Air supply is stopped and the cleaning liquid is supplied from the cleaning tank 800 to the fine bubble supplying unit 400,
The supply of the fine bubbles from the fine bubble supplying unit 400 to the sludge thickening tank 500B and the supply of the cleaning liquid from the cleaning tank 800 to the fine bubble supplying unit 400 are performed at the time of dehydrating the secondary sludge,
Sludge Concentration and Dewatering System in Sewage Treatment Process.
The method of claim 3,
The cleaning liquid supplied to the fine bubble supplying unit 400 is supplied by gravity,
Sludge Concentration and Dewatering System in Sewage Treatment Process.
A method for maintaining and managing the performance of a sludge thickening and dewatering system of a sewage treatment process according to claim 1,
(a) the suspended solids contained in the sewage water flowing into the primary settling tank 200 are settled as the primary sludge, the primary sludge is settled in the primary settling tank 200, 100), treated by microorganisms, separated into treated water and the secondary sludge (SlOO);
(b) the deposited secondary sludge is introduced into the sludge thickening tank 500B and stored (S200);
(c) During the first predetermined time, the air valve (V1) is opened and the sludge valve (V2) is closed, so that the stored secondary sludge flows into the minute bubble supplying part (400) (S300) in which the sludge is supplied to the sludge concentration tank (500B) and stored again.
(d) During the second predetermined time, the air valve (V1) is closed and the sludge valve (V2) is opened, whereby the secondary sludge stored in the sludge concentration tank (500B) A step S400 of flowing into the dehydrator 700, dewatering and discharging to the outside; And
(S500) whether or not the water quality and flow rate of the influent water flowing in or the water quality and flow rate of the secondary sludge flowing into the sludge concentration tank (500B) is greater than or less than a predetermined range;
(f) If the water quality and the flow rate of the inflow water or the water quality and the flow rate of the secondary sludge flowing into the sludge thickening tank 500B are more than or less than the predetermined range, (S600) in which the supply of air to the fine bubble supplying unit (400) is stopped from the cleaning tank (800).
A method for maintenance of sludge concentration and dewatering system performance in sewage treatment process.
6. The method of claim 5,
Instead of steps (e) and (f) above,
bubble supplying unit 400 stops the introduction of the air into the secondary sludge at predetermined intervals and stops the introduction of the fine bubble supplying unit 400 from the cleaning tank 800 to the fine bubble supplying unit 400. [ (S600), wherein the cleaning liquid is supplied to the cleaning liquid supply unit
A method for maintenance of sludge concentration and dewatering system performance in sewage treatment process.
The method according to claim 5 or 6,
The supply of the cleaning liquid from the cleaning tank 800 to the fine bubble supplying unit 400 to the fine bubble supplying unit 400 may be stopped by stopping the introduction of air into the secondary sludge from the fine bubble supplying unit 400,
Wherein during the execution of step (d)
A method for maintenance of sludge concentration and dewatering system performance in sewage treatment process.
6. The method of claim 5,
The step (c)
(c ') During the first predetermined time, the secondary sludge stored in the sludge thickener tank 500B flows into the fine bubble supplying unit 400, and fine bubbles are mixed therein and supplied again to the sludge thickening tank 500B, (S300 '),
The step (d)
(d) the secondary sludge stored in the sludge concentration tank (500B) while being dewatered into the dehydrator (700) after the predetermined first time, (S400) in which the fine bubble supplying unit 400 is introduced and the fine bubbles are mixed and continuously supplied to the sludge thickening tank 500B,
A method for maintenance of sludge concentration and dewatering system performance in sewage treatment process.

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