KR101973736B1 - Method for production of sludge dewatering cake in ceramic membrane filtration process using submerged membrane and pressurized membrane - Google Patents

Abstract

The present invention relates to a method for generating a sludge dehydration cake by concentrating and dehydrating sludge generated in an immersion membrane filtering unit (100) including a ceramic membrane (201). The method for generating a sludge dehydration cake in a ceramic membrane filtration process comprises the steps of: (a) introducing raw water into an immersion membrane filtering unit (100); (b) performing a membrane filtration treatment for the introduced raw water by a ceramic membrane (201) to generate treated water and sludge; (c) operating a suction filtration pump (401) positioned at a rear end of the immersion membrane filtering unit (100) to collect the treated water generated in the step (b) in a treated water tank (600); (d) operating a sludge inflow pump (190) positioned at the other rear end of the immersion membrane filtering unit (100), and introducing the sludge generated in the step (b) into a sludge pressurization membrane filtering unit (900) including another ceramic membrane (940) to be treated with membrane filtration so as to generate a pressurization membrane-treated water and a dehydration sludge; and (e) generating a sludge dehydration cake by introducing and dehydrating the dehydration sludge into a dehydrator (800).

Description

TECHNICAL FIELD The present invention relates to a method for producing a sludge dewatering cake in a ceramic membrane filtration process using an immersion membrane and a pressurized membrane,

The present invention relates to the field of water treatment technology, and more particularly, to a method for producing a sludge dewatering cake in a ceramic membrane filtration process using a pressurized membrane.

There are many differences between the ceramic film and the organic film. 1 is a table for comparing the characteristics of a SiC film, which is one type of ceramic film, and the characteristics of PVDF, which is a kind of organic film. As shown in the table, the ceramic film has a wide range of permissible pH and temperature as compared with the organic film.

Since the ceramic membrane is hydrophilic and can be backwashed, it can be operated stably with high flux and it can remove stains such as bacteria, algae, MLSS, microbial polymer (TEP) and oil which have a negative negative charge on the membrane surface. Is advantageous. In addition, even if only a low concentration of coagulant is injected, the removal rate of dissolved organic matter (DOC) such as Algal-derived Organic Matters (AOM) can be improved, and by adding low concentration of sodium hypochlorite during backwashing, It is possible to reduce the contamination of the membrane. As a result, the immersion membrane filtration process using a ceramic membrane is attracting attention.

FIG. 2 shows a ceramic membrane tower 200 in which a ceramic membrane is formed in a tower form. A plurality of ceramic membranes 201 are assembled into a ceramic membrane module 202 and a plurality of ceramic membrane modules 202 are assembled into a ceramic membrane tower 200.

The treated water outlet 210 and the sprinkler pipe 220 are provided on the top of the ceramic membrane tower 200 built in the immersion membrane filtration unit 100 and the ceramic membrane tower 230 200, and the branch pipe 235 is located at the bottom of the branch pipe. A raw water inflow pump 110 and a raw water inflow valve 115 are provided in the immersion membrane filtration unit 100 where the ceramic membrane tower 200 is located to introduce raw water (see FIG. 3). In addition, a bottom inclined surface 180 is provided below the immersion membrane filtration unit 100 to lower the sludge, and when the sludge discharge valve 195 is opened, the lowered sludge is discharged to the outside.

3 shows a general water treatment conceptual diagram of a membrane filtration process in which the ceramic membrane 201 is immersed to constitute the immersion membrane filtration section 100. FIG.

In the membrane filtration process using the immersion membrane filtration unit 100, the filtration process and the cleaning process are alternately and continuously performed. For example, after a 55-minute filtration step, a 5-minute cleaning step is performed, followed by a 55-minute filtration step and a 5-minute cleaning step. The filtration process and the cleaning process are separated to explain the membrane filtration process.

The filtration process is described first.

The raw water such as wastewater to be treated passes through the raw water inflow valve 115 by the raw water inflow pump 110 and flows into the immersion membrane filtration unit 100 where membrane filtration treatment is performed to produce treated water and sludge.

Pressure is applied to the ceramic membrane 201 by the suction filtration pump 410 so that the treated water is extracted from the ceramic membrane tower 200 through the treated water outlet 210. The extracted treated water passes through the filtration valve 415 And is collected in the treatment water tank 600.

The disinfectant such as chlorine is further introduced from the chlorine injection unit 650 into the treated water collected in the treated water tank 600 and then discharged or reused. In addition to chlorine, other materials capable of disinfection (ozone, manganese dioxide, etc.) may be used, and the term " chlorine injection "

The sludge separated from the immersion membrane filtration unit 100 is collected along the bottom inclined surface 180 at the lower portion of the immersion membrane filtration unit 100 and then passes through the sludge discharge valve 195 by the sludge inlet pump 190 And concentrated in the concentration tank 700. When a certain period of time has elapsed in the thickener tank 700 and the solid-liquid separation is performed to a certain extent, only the substantially precipitated solid material flows into the dehydrator 800 through the dehydrating sludge valve 880 and is dehydrated and discharged as a sludge dewatering cake do. The desalination liquid generated in this process is of course poorly water quality and can not be used again, and is generally re-introduced into the concentration tank 700 and re-concentrated. In the concentration tank 700, a flocculant is injected from the flocculant injecting unit 750 for sedimentation of contaminants for solid-liquid separation.

The cleaning process will be described.

The washing water to be used in the washing process (i.e., reverse washing water) is obtained by collecting a part of the treated water flowing into the treating water tank 600 in the reverse osmosis water storage tank 500.

The cleaning process can be divided into scrubbing by the blower 300, backwash by backwash, and spring-clining.

The air from the blower 300 flows into the acid pipe 230. 2, the acidifier pipe 230 is connected to the acid generator branch 234 under the ceramic membrane tower 200 so that the air introduced from the blower 300 flows through the bottom of the ceramic membrane tower 200 The ceramic film 201 is shaken from the outside to perform scrubbing.

Backwashing by reverse water wash occurs in the direction opposite to that in the treated water discharge line. The backwash water collected in the reverse osmotic water storage tank 500 flows in the reverse direction through the backwash valve 525 by the backwash pump 520 and into the treated water outlet 210 where the treated water was discharged. At this time, the medicine may be injected further using the medicine injection pump 590 and the medicine injection valve 595. [ The backwash water flowing in the reverse direction flows into the interior of the ceramic membrane 201, and the inside of the ceramic membrane 201 is cleaned and then discharged to the outside (that is, inside the immersion membrane filtration unit 100). The raw water flows into the ceramic membrane 201 from the inside of the immersion membrane filtration unit 100 and is then discharged in the opposite direction to the outside of the ceramic membrane 201. [ As a result, it is possible to discharge a foreign matter caught in pores or the like connecting the inside and the outside of the ceramic membrane 201 and clean the inside of the ceramic membrane 201.

The washing water for sprinkling is also supplied from the reverse osmosis water storage tank 500. The wash water passes through the sprinkler valve 515 by the sprinkler pump 510 and flows into the sprinkler pipe 220. Likewise, drug may be injected further using drug injection pump 590 and drug injection valve 596. [ As shown in FIG. 2, the sprinkler pipe 220 is installed to spray the washing water downward from the top of the ceramic membrane tower 200, so that the washing water cleans the outside of the ceramic membrane 201.

As described above, the sludge (i.e., the sludge generated in the submerged membrane filtration unit 100), which is a sediment of raw water such as wastewater, is a waste material of odor, so it is discharged in the form of a cake after being dehydrated in the dehydrator 800, It is a common practice to landfill. However, when the sludge is directly introduced into the dehydrator 800, the dehydration efficiency of the dehydrator 800 is not good due to a lot of fluids contained in the sludge, and the load is increased, resulting in equipment failure and shortening the life span. Accordingly, as described above, the concentration tank 700 is installed at the front end of the dehydrator 800, and the liquid is first separated by solid-liquid separation from the sludge, and then only the solid portion is introduced into the dehydrator 800 (of course, Lt; / RTI > still contains a large amount of liquid). Since the solid-liquid separation of the concentration tank 700 is caused by sedimentation of contaminants, a flocculant for assisting sedimentation is injected from the flocculant injection unit 750 for efficient separation.

There are two problems here.

First, the coagulant injected into the coagulant injecting unit 750 is a polymer flocculant having a high sedimentation efficiency, which is very expensive. Particularly, as the throughput of the immersion membrane filtration unit 100 is increased by using the ceramic membrane 201 having an excellent performance, sludge is increased, and accordingly, the amount of the coagulant to be added is increased, thereby deteriorating the economical efficiency.

Second, the concentrating tank 700 for storing a large amount of sludge for a certain period of time and performing solid-liquid separation is a facility in which the volume of the sludge is considerably large. The general size of the thickener tank 700 corresponds to the size of the immersion membrane filtration unit 100, which is a core facility of the membrane filtration process. Therefore, there is a problem in securing the site where the thickener 700 is to be installed, the problem of connecting the piping and increasing the power of the pump 190 when the site is secured away from the immersion membrane filtration unit 100, And the like. In addition, since the upper part of the concentrating tank 700 is mostly open, there is a problem that the odor is emitted to the surroundings because the sludge is stored.

Therefore, although the immersion membrane filtration unit 100 using the ceramic membrane 201 having a good efficiency can be constructed to obtain a large amount of treated water with respect to the same amount of raw water, a large amount of coagulant is required, Sized thickener tank 700 is required to solve the problem.

(Patent Document 1) Korean Patent No. 10-1117647

(Patent Document 2) Korean Patent No. 10-1235003

(Patent Document 3) Korean Patent No. 10-1345873

(Patent Document 4) Korean Patent No. 10-1342689

(Patent Document 5) Korean Patent No. 10-1473891

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems.

Specifically, a process capable of reducing the load of the dehydrator 800 without adding a coagulant is proposed. In addition, as a process that can replace the concentration tank 700, a relatively compact process is substituted for the problem of the large-size concentration tank 700. [

One embodiment of the present invention for solving the above problems is a method for producing a sludge dewatering cake by concentrating and dewatering sludge produced in an immersion membrane filtration unit 100 including a ceramic membrane 201 (A) introducing raw water into the immersion membrane filtration unit 100; (b) subjecting the introduced raw water to membrane filtration treatment by the ceramic membrane (201), thereby producing treated water and sludge; (c) the suction filtration pump 410 located at the rear end of the immersion membrane filtration unit 100 operates to collect the treated water generated in the step (b) in the treatment water tank 600; (d) a sludge inflow pump 190 located at another rear end of the immersion membrane filtration unit 100 operates, and the sludge generated in the step (b) is introduced into the sludge pressure filtration unit (900) and subjected to membrane filtration, thereby producing pressurized membrane treatment water and dewatering sludge; And (e) the dewatering sludge is introduced into a dehydrator (800) and dehydrated to produce a sludge dewatering cake, wherein the sludge dewatering cake is produced in a ceramic membrane filtration process.

The steps (a) to (c) are performed in a filtration step, and the steps (d) to (e) Process.

The step (e) may further include the steps of: (e1) confirming whether the reference concentration of the concentration of the dewatering sludge produced in the step (d) is satisfied; And (e2), the dewatering sludge valve 880 is opened to allow the dewatering sludge to flow into the dewatering device 800. [0053]

In addition, after the step (d), (f1) checking whether the pressurized membrane treatment water generated in the step (d) satisfies the target treatment water quality; And (f2) are satisfied, it is preferable that the pressurizing-membrane-treatment-water valve 915 is opened so that the pressurized-membrane treatment water is collected in the treatment water tank 600. [

In the step (f2), the pressurized membrane treatment water generated in the pressurized membrane filtration unit (900) by the power of the sludge inflow pump (190) operated in the step (d) And a step of collecting the water.

When the step (f1) is not followed by the step (f3), the pressurized membrane treatment water recirculation valve 925 is opened to recycle the pressurized membrane treatment water to the immersion membrane filtration part 100 .

In the step (f3), the power of the sludge inlet pump (190) operated in the step (d) causes the pressurized membrane treatment water generated in the pressurized membrane filtration unit (900) 100). ≪ / RTI >

In addition, it is preferable that the concentration tank and the coagulant injection unit are not provided at the downstream of the immersion membrane filtration unit 100.

The method according to the present invention can be applied to produce a sludge dewatering cake without increasing the load on the dehydrator while omitting the flocculant and the thickener. That is, the problem of economic loss due to the input of expensive coagulant is solved, and the large-sized concentration tank is omitted, so that the initial investment cost due to site securing and facilities is solved, and the disgusting facility for emitting odor can be omitted .

No additional pump is needed for this. The addition of the pump also complicates the control method and causes economic losses in the initial investment and operation. The present invention uses a pump which is necessary in order to discharge the sludge anyway, that is, It is economical and easy to operate because it can be used for the purpose.

The pressurized membrane treatment water generated in the process of producing the sludge dewatering cake can be stored together in the treatment water tank. Compared with the prior art, the amount of treated water is increased even if the same amount of raw water is treated, and therefore, the treatment efficiency is excellent. For example, if the raw water of the unit capacity 100 has been conventionally collected and 90 sludge has been collected in the treated water tank and 10 sludge has been discharged, the present invention can regenerate 2 to 3 treated sludge out of 10 sludge, The processing efficiency is increased.

1 is a table for comparing a ceramic film and an organic film.
2 is a view for explaining a ceramic membrane tower according to the prior art.
3 is a conceptual diagram of a membrane filtration process according to the prior art.
4 is a conceptual diagram of a membrane filtration process according to the present invention.
5 is a flow chart for explaining the membrane filtration process according to the present invention.

Hereinafter, the present invention will be described in detail with reference to FIG.

The method according to the present invention adopts the sludge pressure membrane filtration unit 900 instead of the concentrated sludge tank 700 and the coagulant injection unit 750 to constitute a process with a direct dewatering system. It goes without saying that the concentration of sludge introduced into the dehydrator 800 is similar to that of the prior art while omitting the thickener 700 and the coagulant injector 750.

Here, when the for-treatment water (in this case, the sludge of the submerged membrane filtration unit 100) flows into the sludge pressurized membrane filtration unit 900, the for-treatment water must be pressurized and introduced. In the conventional process Can be pressurized and inflowed by utilizing the sludge inflow pump 190 which has been used for transferring the sludge to the concentration tank 700 as it is.

The membrane filtration step in the immersion membrane filtration unit 100 is divided into a filtration step and a cleaning step as in the above-described prior art. The cleaning process is substantially the same as in the prior art, and the filtration process will be mainly described here.

The raw water is introduced into the immersion membrane filtration unit 100 by the raw water inflow pump 110 and the raw water inflow valve 115 for the filtration process.

The immersion membrane filtration unit 100 is a membrane filtration tank in which the ceramic membrane 201 is immersed. The raw water flowing into the submerged membrane filtration unit 100 is subjected to membrane filtration treatment by the ceramic membrane 201 to produce treated water and sludge. When the suction filtration pump 410 located at the rear end of the immersion membrane filtration unit 100 operates, the treatment water generated in the immersion membrane filtration unit 100 flows into the treatment water tank 600 and is collected.

At the same time or separately, a sludge inflow pump 190 located at the other rear end of the submerged membrane filtration unit 100 is operated, so that the settled sludge generated in the submerged membrane filtration unit 100 is supplied to the sludge pressure membrane filtration unit 900 . At this time, due to the operation of the sludge inflow pump 190, the sludge is pressurized and flows into the sludge pressure membrane filtration unit 900. The pressurized fluid must be introduced at a predetermined pressure for filtration of the pressurized membrane, without the need for a separate additional pump, utilizing the sludge inlet pump 190, which was used anyway to transfer the sludge.

The sludge introduced into the sludge pressure membrane filtration unit 900 is subjected to membrane filtration treatment by the ceramic membrane 940 provided therein. Accordingly, the treatment water (hereinafter referred to as "pressurized membrane treatment water") and the sludge (hereinafter referred to as "dewatering sludge") are generated.

Since the dewatering sludge is obtained by removing the liquid of the number of the pressurized membrane treatment from the sludge discharged from the submerged membrane filtration section 100, the sludge from the submerged membrane filtration section 100 is agglomerated to a higher concentration Efficiency. Particularly, when a pressurizing membrane is formed using a ceramic membrane capable of stable operation with high flux, sufficient filtration performance is exhibited even when sludge discharged from the immersion membrane filtration unit 100 flows. That is, the sludge pressurized membrane filtration unit 900 can discharge the dewatering sludge having a sufficient concentration to be introduced into the dehydrator 800 even though the solid-liquid separation is not performed in the concentration tank 700 for a predetermined time and the coagulant is not supplied . Actually, the solid-liquid separation of the concentration tank 700 is based on sedimentation of a foreign substance by a flocculant, and thus the efficiency is not high. However, in the present invention, the separation efficiency by the ceramic membrane is high.

Such a dewatering sludge is introduced into the dewatering device 800 through a dewatering sludge valve 880 as in the prior art, and is dehydrated to produce a sludge dewatering cake. The desorption liquid generated in this process can be recycled to the sludge pressurized membrane filtration unit 900.

The pressurized membrane treatment water, which is the liquid portion separated by the ceramic membrane in the sludge pressurized membrane filtration unit 900, has a high permeability to the surface of the ceramic membrane, while the liquid portion remaining after separating the solid from the thickener tank 700 is not good enough to be reused. Water quality is good due to its characteristics.

The pressurized membrane treatment water with good water quality can be collected in the treatment water tank 600 through the pressurized membrane treatment water valve 915 or can be combined with the raw water through the pressurized membrane treatment water recirculation valve 925, 100). ≪ / RTI > No separate pump is required in this process. If the sludge inflow pump 190 uses the force that pushes the sludge to the sludge pressurizing membrane filtration unit 900 as it is, by merely controlling the opening and closing of the valves 915 and 925, Or may be recycled to the immersion membrane filtration unit 100. When water is collected in the treatment water tank 600, the treatment water production amount is increased and the treatment efficiency is increased. In the case of recirculating the raw water to the immersion membrane filtration unit 100, when raw water having poor water quality is introduced, it can be diluted to prevent excessive membrane contamination of the ceramic membrane 201 of the immersion membrane filtration unit 100, 201 can be prevented from deteriorating.

With reference to Fig. 5, the method according to the present invention will be described again step by step.

When the immersion membrane filtration unit 100 is a filtration process (S100), the raw water inflow pump 100 operates and the sludge inflow pump 190 does not operate, and the raw water is filtered in the immersion membrane filtration unit 100 (S310). That is, the submerged membrane filtration unit 100 performs the filtration operation and the sludge pressure membrane filtration unit 900 does not perform the filtration operation (S320).

When the immersion membrane filtration unit 100 is a cleaning process (S100), the raw water inflow pump 100 does not operate and does not supply raw water to the immersion membrane filtration unit 100, and the sludge inflow pump 190 operates, Is conveyed to sludge pressurized membrane filtration unit 900 and filtered (S210). That is, the immersion membrane filtration unit 100 does not perform a filtration operation (performs a cleaning operation), and the sludge pressure membrane filtration unit 900 performs a filtration operation (S220).

In this process, the pressurized membrane treatment water and the dewatering sludge are produced.

It is checked whether the dewatering sludge satisfies the concentration ratio (S240). For example, it is possible to use a method of measuring the suspended solids (SS) of the fluid in the sludge pressure membrane filtration unit 900 and confirming whether it is 2% or the like. If it is not satisfied, the dewatering sludge has not sufficiently removed the fluid enough to flow into the dehydrator 800, so the operation returns to step S230 and the filtration operation of the sludge pressure membrane filtration unit 900 continues. When the dewatering sludge satisfies the concentration ratio, it means that the dewatering sludge is sufficiently concentrated as it flows into the dewatering device 800, so that the dewatering sludge valve 880 is opened (S241) And starts to operate (S242).

At the same time, separately, it is checked whether or not the pressurized membrane treatment water satisfies the target treatment water quality (S250). The pressurized-water treatment water valve 915 is opened to convey the pressurized-membrane-treated water to the treatment water tank 600. In this case, When the pressurized membrane treatment water does not satisfy the target treatment water quality, it means that the treated water has not been transferred to the treatment water tank 600, but a considerable amount of sludge has been removed. In this case, 100). Therefore, the pressurized membrane treatment water recirculation valve 925 is opened, and the pressurized membrane treatment water flows back to the immersion membrane filtration part 100 together with the raw water.

While the present invention has been described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. It will be appreciated that embodiments are possible. Accordingly, the scope of protection of the present invention should be determined by the claims.

100: immersion membrane filtration section
110: raw water inflow pump
115: raw water inlet valve
180: bottom slope
190: Sludge inflow pump
195: Sludge discharge valve
200: Ceramic membrane tower
201: Ceramic film
202: Ceramic membrane module
210: treated water outlet
220: Sprinkler piping
230: Heat pipe
235: Distributor for acid
300: Blower
410: Filtration pump for suction
415: Filtration valve
500: Stationary water storage tank
510: Sprinkler pump
515: Sprinkler valve
520: backwash pump
525: Backwash valve
590: Drug infusion pump
595, 596: Pharmaceutical injection valve
600: Treatment tank
650: chlorine injection part
700: Enrichment tank
750: coagulant injection unit
800: Dehydrator
880: Dewatering sludge valve
900: sludge pressure membrane filtration section
915: Pressurized membrane treatment water valve
925: Pressurized membrane treated water recirculation valve
940: Ceramic membrane

Claims (8)

A method for producing a sludge dewatering cake by concentrating and dewatering sludge produced in an immersion membrane filtration unit (100) comprising a ceramic membrane (201)
(a) introducing raw water into the immersion membrane filtration unit 100;
(b) subjecting the introduced raw water to membrane filtration treatment by the ceramic membrane (201), thereby producing treated water and sludge;
(c) the suction filtration pump 410 located at the rear end of the immersion membrane filtration unit 100 operates to collect the treated water generated in the step (b) in the treatment water tank 600;
(d) a sludge inflow pump 190 located at another rear end of the immersion membrane filtration unit 100 operates, and the sludge generated in the step (b) is introduced into the sludge pressure filtration unit (900) and subjected to membrane filtration, thereby producing pressurized membrane treatment water and dewatering sludge; And
(e) the dewatering sludge is introduced into the dehydrator 800 and dehydrated to produce a sludge dewatering cake,
The process of the immersion membrane filtration unit 100 is divided into a filtration process and a cleaning process,
Wherein the steps (a) to (c) are performed in a filtration step,
The steps (d) to (e) are performed in a cleaning process,
The step (e)
(e1) confirming whether the reference concentration ratio of the concentration of the dewatering sludge generated in the step (d) is satisfied; And
(e2), the dewatering sludge valve (880) is opened and the dewatering sludge is introduced into the dehydrator (800)
A Method for Producing Sludge Dewatering Cake in Ceramic Membrane Filtration Process.
delete delete The method according to claim 1,
After the step (d)
(f1) confirming whether or not the pressurized membrane process water generated in the step (d) satisfies the target process water quality;
(f2) is satisfied, the pressurizing-membrane-treatment-water valve (915) is opened to collect the pressurized-membrane treatment water in the treatment bath (600).
A Method for Producing Sludge Dewatering Cake in Ceramic Membrane Filtration Process.
5. The method of claim 4,
The step (f2)
And a step of collecting the pressurized membrane treatment water generated in the pressurizing membrane filtration unit (900) by the power of the sludge inflow pump (190) operated in the step (d) in the treatment water tank (600)
A Method for Producing Sludge Dewatering Cake in Ceramic Membrane Filtration Process.
5. The method of claim 4,
After the step (f1)
(f3) is not satisfied, the pressurized membrane treatment water recirculation valve (925) is opened to recycle the pressurized membrane treatment water to the immersion membrane filtration part (100)
A Method for Producing Sludge Dewatering Cake in Ceramic Membrane Filtration Process.
The method according to claim 6,
The step (f3)
The step of recirculating the pressurized membrane treatment water generated in the pressurized membrane filtration unit 900 to the immersion membrane filtration unit 100 by the power of the sludge inflow pump 190 operated in the step (d) ,
A Method for Producing Sludge Dewatering Cake in Ceramic Membrane Filtration Process.
The method according to claim 1,
And a condenser and a coagulant injection unit are not provided at a downstream end of the immersion membrane filtration unit 100,
A Method for Producing Sludge Dewatering Cake in Ceramic Membrane Filtration Process.

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