KR102516413B1 - Thickening system for sludge generated in water treatment process - Google Patents

Abstract

Disclosed is a system for concentrating sludge generated in a water treatment process, which can simplify sludge concentration using a separation membrane in a single separation membrane facility process, while sludge concentration and drawing processes may be performed continuously and smoothly. The present invention provides a continuous sludge concentration system, which is a system for concentrating sludge generated in a water treatment process, comprising: a separation membrane tank which is equipped with a separation membrane therein and into which the sludge is introduced to concentrate the sludge through the separation membrane and to discharge treated water; and a circulating water tank drawing the sludge transferred from the separation membrane tank out of the system and circulating some of the transferred sludge into the separation membrane tank, wherein the concentration in the separation membrane tank and the drawing in the circulating water tank are performed simultaneously.

Description

Sludge thickening system generated in water treatment process {Thickening system for sludge generated in water treatment process}

The present invention relates to a sludge thickening system, and more particularly, to a sludge thickening system generated in a water treatment process.

A technique for efficiently concentrating sludge inevitably generated in a biological treatment process in sewage and sewage treatment and stably securing the quality of treated water separated from solids has been disclosed.

The sludge generated in the biological treatment process is concentrated and stabilized to secure the inlet solids concentration required for each dewatering facility. 2 to 3% (wt/v), 0.4 to 0.8% (wt/v) for screw press dehydrators, 2 to 3% (wt/v) for belt press dehydrators, and 2 to 3% (wt/v) for centrifugal dehydrators. 0.8 to 2% (wt/v).

In general, in the water treatment process excluding the MBR (Membrane Bio Reactor) process, the solids concentration in the aerobic reactor is around 3,000 mg/L (0.3%), and the solids concentration in the surplus sludge in the secondary settling tank is 6,000 to 10,000 mg/L (0.6 to 1%) ), the drawn sludge must be adjusted to the concentration of the inlet sludge exemplified above through the thickening and stabilization process in order to properly operate the dehydrator.

At this time, in order to adjust the concentration of the inflow sludge suitable for the dehydrator, it is necessary to adjust the amount of the surplus sludge entering the final dehydrator to about 10% through the thickening and stabilization process. Since it is transported to the inlet in the form of return water, it increases by about 2% compared to the design flow rate, which causes a decrease in the efficiency of the water treatment process.

On the other hand, in sludge drawing, most sludge is drawn in the form of surplus sludge in the secondary settling tank, but when a separation membrane is applied, it is possible to concentrate even by drawing directly from the aerobic tank.

Korean Patent Registration No. 10-0540986 discloses a treatment device using a separation membrane as an advanced wastewater treatment device using MBR, but the first stage of concentration and the inflow of surplus sludge It is a semi-batch method consisting of a two-stage concentration that stops the concentration and filters the concentrated sludge in batches until the level of drawing out the concentrated sludge.

The present invention is a sludge concentration system generated in a water treatment process, which can be simplified to one separation membrane facility process as a sludge concentration using a separation membrane, but to provide a sludge concentration system that allows the sludge concentration and drawing process to be carried out continuously and smoothly do.

In addition, it is intended to provide a sludge thickening system capable of selectively performing batch operation as well as continuous operation according to the need for water treatment process operation.

In order to solve the above problems, the present invention is a system for concentrating sludge generated in a water treatment process, which has a separation membrane therein, and in which the sludge flows and concentrates the sludge through the separation membrane to discharge treated water; and a circulating water tank which draws the sludge transferred from the membrane tank out of the system and circulates some of the transferred sludge to the membrane tank; A sludge thickening system is provided.

In addition, the inflow sludge provides a continuous sludge thickening system, characterized in that the concentration is 2,000 to 12,000 mg / L.

In addition, a continuous sludge concentrating system is provided, characterized in that a diffuser is installed at the lower part of the separation membrane tank and the lower part of the circulating water tank, respectively.

In order to solve the another problem, the present invention is a sludge thickening system generated in a water treatment process, a separation membrane is provided therein, and the sludge is introduced and the sludge is concentrated through the separation membrane to discharge treated water. article; and a circulating water tank for drawing the sludge transferred from the membrane tank out of the system and circulating a part of the transferred sludge to the membrane tank, wherein the membrane tank and the circulating water tank are separated by a partition with a sluice gate formed thereon, In a state where the sluice gate is closed, concentration in the separation membrane tank and drawing in the circulating water tank are simultaneously performed, and in a state where the sluice gate is opened, a mixture of continuous and batch type in which drawing is performed after completion of concentration in the membrane tank. A sludge thickening system is provided.

According to the present invention, a sludge concentrating system using a separation membrane is provided with a separation membrane tank having a separation membrane therein and a circulating water tank for drawing sludge transferred from the separation membrane tank out of the system and circulating some of the transferred sludge to the separation membrane tank, , It is possible to provide a continuous sludge thickening system in which concentration in a membrane tank and drawing in a circulating water tank are performed at the same time.

In addition, the membrane tank and the circulating water tank are separated by a partition wall with a sluice gate formed thereon, so that a mixed sludge thickening system capable of continuous operation by closing the sluice gate or batch operation by opening the sluice gate can be provided, if necessary.

1 is a block diagram showing a sludge thickening system according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted. In order to clearly describe the present invention in the drawings, parts irrelevant to the description have been omitted, similar reference numerals have been assigned to similar parts throughout the specification, and throughout the specification, certain parts can be said to "include" certain components. When, this means that other components may be further included, rather than excluding other components, unless otherwise stated.

1 is a block diagram showing a sludge thickening system according to an embodiment of the present invention.

Referring to FIG. 1 , a sludge thickening system 100 according to an embodiment of the present invention includes a membrane separation tank 110 and a circulating water tank 120.

The separation membrane tank 110 is a tank into which excess sludge generated in the water treatment process is introduced, and a separation membrane 111 is provided therein so that the introduced sludge is concentrated through the separation membrane 111 . The concentrated sludge may be discharged out of the system through a discharge facility or the like through the suction pump 112.

In the present invention, the water treatment process is not particularly limited as long as it is a water treatment process that generates excess sludge, and may be, for example, a biological treatment process. can be made

The concentration of the inflowing surplus sludge may be in the form of relatively high-concentration raw water considering the number of separators 111 used, preferably 2,000 to 12,000 mg / L, more preferably 3,000 to 10,000 mg It can be /L.

In addition, in the present invention, the type and shape of the separation membrane 111 are not particularly limited, but considering the concentration of influent raw water, it is preferable to apply a submerged microfiltration membrane (MF).

In general, in sludge concentration, sludge concentration for dehydration is secured through several steps, but sludge concentration using a separation membrane can be simplified with one separation membrane equipment process. However, the process of thickening and stabilizing the sludge to secure the sludge concentration for dehydration causes odors because there is no aerobic condition, and the inflow concentration is increased by about 5% compared to the inflow concentration due to the high concentration of the return water.

In the present invention, the diffusion pipe 113 is provided at the bottom of the separation membrane tank 110 so that air can be supplied through the blower 114, and the concentration using such a separation membrane maintains aeration conditions with continuous aeration to prevent odor generation. The amount of treated water (reflux water) can be minimized, and the concentration of treated water (reflux water) is very low, so the load of inflow water can be reduced. In particular, suspended solids (SS) are rarely generated, and it is possible to secure stable water quality by reducing the inflow load by treated water (return water) by minimizing phosphorus release. Here, it is a matter of course that air can be supplied through the blower 122 by installing the diffuser 121 at the bottom of not only the separation membrane tank 110 but also the circulating water tank 120 .

In addition, since the inflow sludge concentration can be adjusted according to the operation time of the membrane tank 110, the inflow concentration suitable for all dehydrators can be secured, and thus the efficiency of the dehydrator can be maximized.

Here, in the case of operating only the membrane tank 110 equipped with the separation membrane 111 during sludge concentration, it is difficult to simultaneously perform the sludge concentration and discharge of treated water and the drawing process of the concentrated sludge, but in the present invention, the sludge concentration and drawing process Means are employed to ensure simultaneous execution.

That is, in the present invention, by providing a circulating water tank 120 for drawing the sludge transferred from the membrane tank 110 out of the system and circulating some of the transferred sludge to the membrane tank 110, A completely continuous operation in which the concentration and drawing in the circulating water tank 120 are performed at the same time is possible.

Specifically, in a state in which the circulating water tank 120 is filled with the sludge transferred from the membrane tank 110 by the sludge transfer pump 115, it is divided into the membrane tank 110 and the partition wall 130, so the membrane tank ( Independently of the concentration process in 110), the sludge can be drawn out of the system, so raw water inflow into the membrane tank 110, concentration in the membrane 111, sludge transfer from the membrane tank 110 to the circulating water tank 120, and Completely continuous operation is possible so that sludge can be drawn out from the circulating water tank 120 simultaneously. Sludge extraction from the circulating water tank 120 may be performed by the concentrated sludge extraction pump 123.

At this time, in the circulating water tank 120, some of the sludge is circulated to the separation membrane tank 110 by the circulation pump 124, so that the sludge concentration for dehydration can be secured. That is, the concentration of the circulating water tank 120 is usually higher than that of the membrane tank 110 due to the sludge flowing from the membrane tank 110, but in a situation where the sludge concentration for dehydration is not reached, the sludge from the circulating water tank 120 is transferred to the membrane tank 110, and finally induces the concentration of the circulating water tank 120 to be maintained higher than that of the separation membrane tank 110 by a desired concentration, so that the sludge can be smoothly and continuously drawn out.

According to another embodiment of the present invention, the separation membrane tank 110 and the circulating water tank 120 are separated by a partition wall 130 having a water gate 140 formed thereon, and the water gate 140 is closed as necessary to continuously operate. By operating or opening the sluice gate 140, a mixed sludge thickening system capable of batch operation can be implemented.

That is, in a state where the sluice gate 140 is closed, as described above, a continuous operation in which condensation in the membrane tank 110 and drawing in the circulating water tank 120 are simultaneously performed is possible, and the sluice gate 140 is In the open state, since it is the same as the system provided with a single membrane tank 110, it is possible to perform a batch operation in which drawing is performed after concentration in the membrane tank 110 is completed.

In the above sludge concentration system according to the present invention, the dehydration process is not required during the time to concentrate the sludge in the membrane tank 110 in which the membrane 111 is installed and the time to concentrate the sludge again after emptying the membrane tank 110, resulting in As the number of dehydration processes is reduced, maintenance costs such as labor costs and chemical costs can be reduced.

Example of designing a concentration system using a separation membrane

For example, when raw water with a BOD of 200 mg/L flows in from a treatment facility with a capacity of 1,000 ㎥/day, the amount of sludge withdrawn is about 90 kg/day, and 0.25% aerobic sludge is directly drawn from the bioreactor to raise the sludge concentration to 2.5%. In the case of concentration, the concentration facility using a separation membrane is as follows, and the expected results of the operation of the concentration system are shown in Table 1 below.

[Enrichment facility]

- Membrane tank: 3.0 mW×3.0 mL×2.0 mHe

- Circulating water tank: 3.0 mW×3.0 mL×2.0 mHe

- Membrane facility: 1 meal

- The sludge dewatering process is operated once every 5 days with the volume of the separation membrane tank and the circulating water tank each being 18 ㎥, and when the capacity of the dehydration facility is 5 ㎥/h, it is completed after about 4 to 5 hours of operation.

- Depending on the capacity of the membrane tank, the operating cycle of the dehydration process can be changed

division 1 day 2 days 3 days 4 days 5 days 6 days 7 days 8 days 9 days 10 days 11 days 12 days 13th 14 days 15th 16th 1% sludge drawing
(kg/day) 90 180 270 360 450 540 630 720 810 900 540 630 720 810 900 540 Membrane tank/circulating water tank
Sludge concentration (%) 0.25 0.5 0.75 1.0 1.25 1.5 1.75 2.0 2.25 2.5 1.5 1.75 2.0 2.25 2.5 1.5 Operation of dehydrator × × × × × × × × × ◎ × × × × ◎ × number of production
(㎥/day) 0 36 36 36 36 36 36 36 36 36 36 36 36 36 36 36

Referring to Table 1, the operation of the dehydrator is performed 10 days after the first time (the dewatering process is unnecessary for about 10 days when restarting after drawing out the entire amount of the membrane tank and circulating water tank), and then 5 days later, it can be seen that the number of dehydration processes is greatly reduced. there is. Produced water (separator treated water) can be generated for 24 hours (~1.5 ㎥/h production), and can be transported to discharge facilities (final discharge) or inflow facilities (raw water distribution tank, flow control tank) depending on the conditions of the treatment facility It can be designed to do so, and it can be transported to the inlet facility where the dehydration filtrate is generated in the dehydration process.

In addition, the inflow sludge concentration can be adjusted according to the operation time of the membrane tank, so that the inflow concentration suitable for all dehydrators can be secured, and the water treatment efficiency can be maximized.

In the above, preferred embodiments of the present invention have been described in detail with reference to the drawings. The description of the present invention is for illustrative purposes, and those skilled in the art will understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention.

Therefore, the scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning, scope and equivalent concept of the claims are included in the scope of the present invention. should be interpreted

100: sludge concentration system 110: membrane tank
111: separator 112: suction pump
113: Separation tank lower aeration tube 114: Separation membrane tank aeration blower
115: sludge transfer pump 120: circulating water tank
121: circulating water tank lower diffuser 122: circulating water tank diffuser blower
123: concentrated sludge extraction pump 124: circulation pump
130: bulkhead 140: water gate
150: screen

Claims (4)

As a sludge thickening system generated in the water treatment process,
a separation membrane tank having a separation membrane therein, in which the sludge flows in and concentrates the sludge through the separation membrane to discharge treated water; and
a circulating water tank for drawing the sludge transported from the membrane tank out of the system and circulating a part of the transported sludge to the membrane tank;
Including, wherein the separation membrane tank and the circulating water tank include a partition wall with a water gate formed thereon,
In a state in which the water gate is closed, concentration in the membrane tank and drawing in the circulating water tank are simultaneously performed,
In a state where the sluice gate is open, after the concentration is completed in both the connected membrane tank and the circulating water tank, the mixed sludge thickening system can be operated in a continuous or batch manner in which drawing is performed in the circulating water tank. According to claim 1,
Mixed sludge thickening system, characterized in that the incoming sludge has a concentration of 2,000 to 12,000 mg / L. According to claim 1,
Mixed sludge concentrating system, characterized in that a diffuser is installed in the lower part of the separation membrane tank and the lower part of the circulating water tank, respectively. delete

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