KR101309990B1 - Water treatment apparatus comprising settling membrane separation tank and water treatment method using thereof - Google Patents

Abstract

The present invention provides a mixed agglomeration tank in which the treated water introduced is mixed with agglomerated drugs and aggregated; And a sedimentation membrane separation tank in which the sludge of the treated water mixed and aggregated in the mixing agglomeration tank is precipitated, and the membrane module is immersed. The membrane modules are arranged vertically in the precipitation membrane separation tank, It relates to a water treatment device characterized in that the lower end is closed so that only the inlet can be introduced into the water.
Through the present invention, it is possible to save the construction site and construction cost for a separate settling tank, and since the precipitation process, which takes up most of the time of the water treatment, is performed simultaneously with the filtration process through the membrane, the water treatment time can be shortened.

Description

Water treatment apparatus comprising settling membrane separation tank and water treatment method using the same

The present invention relates to a water treatment apparatus and a water treatment method, and more particularly, to a water treatment apparatus including a sedimentation membrane separation tank in which sedimentation of sludge and filtration through a separation membrane simultaneously occur without having to separately set a sedimentation tank, and a water treatment method using the same. It is about.

In addition, the water treatment apparatus including the present invention sedimentation membrane separation tank is designed as a wastewater treatment water reuse device for reuse of the wastewater after the first biological treatment, or may be used as any device used to purify water, such as a purified water treatment device. Can be.

The conventional method for recycling wastewater treatment water is by combination of processes such as filtration, activated carbon adsorption and disinfection. However, depending on the performance and management of the unit process, such as filtration and adsorption, the treated water quality may fall below the required level of reused water, in particular, the solid removal ability was not excellent, and the required land area and maintenance cost burden were high.

In recent years, the introduction of a reverse osmosis membrane (RO) process is increasing. For the stable operation of the reverse osmosis membrane, the water quality of the treated water is required to be below the SDI (Silt Density Index) 3.0 level. Branch membrane filtration process is essential.

The filtration process through the membrane has the advantage of obtaining a relatively constant water quality without restriction on the quality of the water to be treated except for dissolved substances, but the degree of contamination of the membrane can vary greatly depending on the quality of the water to be treated. That has a fatal drawback.

In addition, the filtration process through the membrane includes a pressurized type for taking pretreated treated water and supplying it to the membrane module and a submerged type for filtration of the treated water by immersing the membrane module in a membrane separation tank. Pressurized type has the disadvantage of high energy requirement.

The immersion type has been pointed out as the biggest problem of turbidity management of treated water. As the filtration by the immersion membrane proceeds, the sludge filtered by the membrane is concentrated in the membrane separation tank. Furthermore, in the case of the immersion type, aeration for washing the membrane is essential, and the sludge precipitated in the membrane separation tank is agitated throughout the membrane separation tank by the aeration. As the filtration by the immersion type separation membrane proceeds, the sludge of the entire membrane separation tank is performed. This resulted in higher concentrations.

Therefore, in order to control the turbidity of the water to be treated, water bodies in a sufficiently stirred membrane separation tank of 5 to 10% of raw water are discarded. This results in a 20-fold increase in disposal. For example, raw water turbidity of about 2 to 10 NTU after the coagulation process is concentrated to 20 to 100 NTU, even if 10% of the waste volume (90% recovery) is applied in the membrane separation tank. It is virtually impossible.

Accordingly, the Republic of Korea Patent Publication "water treatment system using the immersion membrane device (No. 10-2010-0053155)" discloses a water treatment device that separates the sedimentation tank in front of the membrane separation tank, the Republic of Korea Patent Publication "Cartridge filter type FM Membrane Separation Apparatus (No. 2000-0006691) using a membrane discloses a water treatment apparatus having a separate sedimentation tank at the bottom of the membrane separation tank.

However, the above two Korean Patent Publications only differ in the location of the sedimentation tank, but have a separate sedimentation tank and a separate sedimentation tank. When such a separate sedimentation tank is provided, a huge space for the sedimentation tank is required, The disadvantage is that a time-consuming settling process is required separately.

"Membrane separation apparatus using cartridge filter type FM membrane (No. 2000-0006691)" will be described below with reference to FIG.

1 (A) shows the membrane module of the "membrane separation device using a cartridge filter type FM membrane (No. 2000-0006691)", (B) shows the membrane module of the present invention. As shown in Figure 1 (A) it can be seen that the treated water flows through the lower end (a) of the membrane module. However, in (B) it can be seen that the water to be treated only through the top (b) of the membrane module, there is no outflow of the water to be treated through the bottom (c).

Through this, "membrane separation device using cartridge filter type FM membrane (No. 2000-0006691)" leads to the conclusion that the depth for the sludge deposition layer (sedimentation tank) separate from the membrane module installation depth should be placed under the membrane module. . Since the separate depth for the sludge sediment is an underground structure, it is more expensive for civil engineering than the "water treatment system using the immersion membrane device (No. 10-2010-0053155)" in which a sedimentation tank is installed in front of the membrane module.

In addition, when operating the aeration in a state where the sedimentation is not made completely, there is a disadvantage that the agitation of the sludge reaches the entire tank.

An object of the present invention for solving the conventional problems as described above is to provide a water treatment apparatus including a sedimentation membrane separation tank that can manage the turbidity of the water to be treated without having to separate the sedimentation tank.

In addition, the present invention provides a water treatment method using a water treatment apparatus including a precipitation membrane separation tank capable of filtration through a separation membrane without waiting for a separate precipitation process.

In order to solve the above problems, the present invention, a mixed agglomeration tank in which the inflow of the water to be treated is mixed with the agglomerated drugs and aggregated; And a precipitation membrane separation tank in which the sludge of the treated water mixed and agglomerated in the mixing agglomeration tank is precipitated, and the membrane module is immersed, wherein the membrane module is arranged vertically in the precipitation membrane separation tank. It provides a water treatment device characterized in that the lower end is closed so that only the inlet of the membrane module to the inflow of the treated water.

The apparatus may further include a partition wall immersed in the precipitation membrane separation tank so that sludge of the treated water mixed and agglomerated in the mixing flocculation tank is precipitated, and the partition wall is disposed between the mixing flocculation tank and the separation membrane module. .

In addition, the membrane module, the housing of the cylindrical upper and lower opening; A case housed in the housing; A hollow fiber membrane accommodated in the case; And it includes a diffuser located in the lower portion of the case, it is preferable that a plurality of membrane modules are immersed in the precipitation membrane separation tank.

In addition, the flocculation chemical tank for containing and providing the flocculation chemical to be introduced into the treated water; And an inline mixer in which the flocculated chemical provided in the flocculated chemical tank and the inflowed treated water are mixed.

In addition, it is preferable to further include a stirrer located in the lower portion of the precipitation membrane separation tank.

In addition, it is preferable to further include a sludge collection hopper connected to the bottom of the sedimentation membrane separation tank.

In addition, it is preferable to further include a sludge waste pump located in the sludge collection hopper.

In addition, a plurality of the mixing agglomeration tank is located, it is preferable to further include a stirrer immersed in the mixing agglomeration tank.

In addition, it further comprises a turbidimeter and a water gauge immersed in the sedimentation membrane separation tank, the turbidimeter and the water gauge is preferably located between the partition wall and the membrane module.

In order to solve the above problems, the present invention, (a) a step of injecting a flocculating drug into the inflowed treated water mixed and agglomerated the inflowed treated water; (b) precipitating sludge of the mixed and agglomerated treated water; And (c) filtering the sludge-prepared water by the membrane module; It includes, step (b) and step (c) provides a water treatment method, characterized in that made in one tank.

In addition, after the step (c), (d) preferably further comprises the step of sucking the treated water filtered on the membrane module.

As described above, in the sedimentation membrane separation tank, the sedimentation process and the filtration process through the separation membrane are simultaneously performed. Therefore, the construction site and construction cost for installing the sedimentation tank can be saved, and the sedimentation process, which takes most of the time for water treatment, Simultaneously with the filtration process through the membrane can reduce the water treatment time.

1 is a schematic diagram showing the difference between the membrane module of the present invention and the present invention,
2 is a cross-sectional view showing a water treatment apparatus including a sedimentation membrane separation tank according to the present invention;
3 is a cross-sectional view showing in detail the membrane module,
4A is a cross-sectional view showing a process of generating treated water filtered through a separator through a suction pump;
4B is a cross-sectional view showing a process of washing the separator by applying an aeration to operate the blower; and
4C is a cross-sectional view illustrating the sludge disposal process.

"Upper water layer" used hereinafter is defined as a low turbidity water layer on the top of the sedimentation membrane separation tank having a turbidity of about 10 NTU or less generated by the precipitation of sludge in the sedimentation membrane separation tank.

Description of Structure of Water Treatment Apparatus Including Sedimentation Membrane Separation Tank

Hereinafter, a structure of a water treatment apparatus including a precipitation membrane separation tank according to the present invention will be described in detail with reference to the accompanying drawings.

The water treatment apparatus including the precipitation membrane separation tank according to the present invention may include a mixing flocculation tank 100, a precipitation membrane separation tank 200, and a separation membrane module 300.

In the mixed flocculation tank 100, the treated water 10 introduced is mixed with the flocculating chemical and aggregated.

Preferably, the apparatus further comprises a coagulation drug tank 410 for receiving and providing a coagulation drug. In addition, the flocculating chemicals provided from the flocculating chemical tank 410 may further include an in-line mixer 420 in which the water to be treated 10 is mixed. In this way, the flocculation chemical tank 410 and the inline mixer 420 may be separately placed to input the flocculation chemical at a constant ratio, and the treated water 10 and the flocculation chemical may be strongly mixed.

The coagulant may include, for example, Alum (alum), iron ions, etc., which may aggregate the dissolved total phosphorus (TP), that is, insoluble (solidify) the dissolved phosphorus. In this case, it is possible to remove dissolved substances that cannot be filtered by the UF-class separator.

Preferably, the mixed flocculation tank 100 is located in a number. Although two mixed agglomeration tanks 100 are shown in FIG. 2, the mixing tank alone or a mixed and agglomerated tank configuration may be possible through a coagulation test considering the separation membrane filtration capacity of the target water.

In addition, it may further include a stirrer 120 immersed in the mixing agglomeration tank (100). The mixing flocculation tank 100 is stirred by the stirrer 120 according to the optimum GT value derived from the coagulation test.

The residence time in the mixed coagulation bath 100 is 5 to 10 minutes, the mixing strength is about 200 to 250 sec ^-1 , and the pH is about 6 to 8 when using aluminum (aluminum) -based coagulant such as Alum and PAC. It is preferable.

Preferably, the turbidity meter 130 or MLSS measuring system immersed in the mixing flocculation tank 100 is located, it is possible to measure the turbidity.

Precipitation membrane separation tank 200 is where the mixed water and agglomerated treated water 10 in the mixing agglomeration tank 100 is introduced, and the precipitation of sludge and the filtration process through the separation membrane occurs.

Preferably, it further comprises a partition wall 210 immersed in the precipitation membrane separation tank (200).

As shown in FIG. 2, the partition wall 210 may be formed such that the water to be treated 10 is movable only below the partition wall 210 in the precipitation membrane separation tank 200.

The partition wall 210 is positioned between the mixing flocculation tank 100 and the separation membrane module 300 to minimize disturbance of the water 10 to be introduced from the mixing flocculation tank 100. Therefore, the sludge of the water to be treated 10 introduced is advantageous to gravity settling.

Due to the sludge precipitated by gravity sedimentation, the inside of the precipitation membrane separation tank 200 is formed with a high turbidity water layer at the bottom, a low turbidity water layer of about 10 NTU or less can be formed at the top.

The membrane module 300 is immersed in the precipitation membrane separation tank 200, but the membrane module 300 will be described in detail below.

Preferably, the stirrer 220 is positioned below the precipitation membrane separation tank 200. The stirrer 220 may be used to dispose of the immersed sludge by being located under the precipitation membrane separation tank 200 as shown in FIG. 4C.

Preferably, the sludge collection hopper 510 is connected to the lower end of the precipitation membrane separation tank 200. The sludge collection hopper 510 serves to collect sludge, and with the aid of the stirrer 220, efficient collection is possible.

A sludge waste pump 520 may be located within the sludge collection hopper 510 so that the sludge waste pump 520 may discard the collected sludge through the sludge waste line 540. The sludge waste line 540 is preferably equipped with a turbidity meter 530 or MLSS meter to measure the concentration of the concentrated sludge.

In addition, the precipitation membrane separation tank 200 may be immersed in a turbidity meter 230 or MLSS meter, and the water level meter 240. The immersed turbidimeter 230 and the water gauge 240 measure the turbidity and level of the precipitation membrane separation tank 200 to provide a basis for controlling each process to be efficiently performed by a user or a controller.

Separation membrane module 300 may be immersed so that the cylindrical shape is vertically arranged in the precipitation separation tank 200 as shown in FIG. As shown in FIG. 3, the membrane module 300 includes a housing 310, a case 320, a hollow fiber membrane 330, an diffuser 340, a treated water storage unit 351, and treated water discharged water 352. It may include.

The housing 310 may form the outermost part of the membrane module 300 and may have a cylindrical shape having upper and lower portions open.

The inlet 311 may be formed in the housing 310, and the inlet 311 is formed at the top of the housing 310 as shown in FIG. 3, and any water to be treated 10 is disposed at the bottom of the housing 310. It should be noted that the flow chart of Fig. 11 is closed so that no flow can occur.

The case 320 is accommodated in the housing 310 and may be cylindrical.

An outlet 321 may be formed in the case 320, and a portion of the treated water 10 that has passed through the hollow fiber membrane 330 is discharged (B of FIG. 3). The other part is stored in the treated water storage unit 351 (A in FIG. 3).

The hollow fiber membrane 330 may be adhered only by the hollow fiber adhesive portion 322 without being potted with an adhesive such as epoxy or urethane in the case 320.

The diffuser 340 is located at the bottom of the case 320 to provide aeration to clean the hollow fiber membrane 330. The diffuser 340 may be connected to the blower 341 through the blower pipe 342 to provide aeration (D of FIG. 3).

The treated water storage unit 351 is a place where the treated water filtered by the hollow fiber membrane 330 is stored, and the treated water stored in the treated water storage unit 351 is disposed in the suction pump 600 through the treated water discharge unit 352. It is sucked by suction (C of FIG. 3).

Separation membrane module 300 may be immersed in the precipitation membrane separation tank 200 to increase the filtration efficiency.

Description of the water treatment method

Hereinafter, a water treatment method using a water treatment apparatus including a precipitation membrane separation tank according to the present invention will be described in detail with reference to FIG. 4A.

The water treatment method using a water treatment apparatus including a sedimentation membrane separation tank according to the present invention comprises the steps of: (a) a step of mixing and agglomerating the treated water (10) introduced into the treated water (10) introduced into the treated water; (b) precipitating sludge of the mixed and agglomerated treated water 10, and (c) filtering the upper water layer of the treated water 10 from which the sludge is precipitated by a membrane module. In addition, the method may further include (d) sucking the treated water filtered at the upper part of the membrane module.

The flocculated chemical is introduced and the treated water 10 introduced into the mixed agglomeration tank 100 is mixed and agglomerated. The mixed and agglomerated treated water 10 is introduced into the precipitation membrane separation tank 200 to form a partition wall ( 210) the sludge's gravity sedimentation is accelerated, and the sludge precipitates to form a lower turbidity layer with a high turbidity and an upper aqueous layer with a turbidity of 10 NTU or less.

As the suction pump 600 operates, only the upper water layer having a turbidity of 10 NTU or less is introduced into the inlet 311 formed at the top of the separator module 300 and filtered through the hollow fiber membrane 330. The filtered water thus stored is stored in the treated water storage unit 351 (A of FIG. 3) and sucked through the treated water discharge unit 352 according to the suction of the suction pump 600 (FIG. 3C).

How to maintain turbidity in the upper water column

Hereinafter, a method of maintaining turbidity of the upper water layer will be described in detail.

The turbidity of the water 10 to be introduced through the inlet 311 of the membrane module 12 immersed in the precipitation membrane separation tank 200 may be monitored by the turbidimeter 230 immersed in the precipitation membrane separation tank 200. Can be. In view of the safety factor in monitoring, it is preferable to read the numerical value at a depth lower than the depth of the inlet 311. When the turbidity level indicated by the turbidimeter 230 is increased, a flocculation aid having a weighted flocculation effect is added or changed in the amount of chemicals mixed with the water to be treated (10) to increase the sedimentation of the sludge to settle the membrane separation tank ( The upper water layer may be managed by increasing the density of the sludge 20 in the 200.

In addition, when the turbidity level indicated by the turbidimeter 230 is sharply increased, a method of increasing the concentrated sludge waste by reducing the inflow of the water 10 for a predetermined time or increasing the operating time of the sludge waste pump 520. Control is possible.

In addition, as will be described below, it is necessary to control the height of the sludge deposited on the basis of the minimum depth of the circulating flow in the hollow fiber membrane 330 cleaning process to reduce the disturbance caused by the sludge as much as possible.

Description of Hollow Fiber Membrane Cleaning Process

Hereinafter, the cleaning process of the hollow fiber membrane 330 will be described in detail with reference to FIG. 4B.

In the water treatment method using a water treatment apparatus including a precipitation membrane separation tank according to the present invention, the process of filtering the water to be treated 10 and the process of washing the hollow fiber membrane 330 should be alternately performed. The filtration process of the water 10 to be treated is performed for about 11 to 12 minutes, and the hollow fiber membrane 330 cleaning process is alternately performed for about 30 seconds to 1 minute.

When the hollow fiber membrane 330 cleaning process is started, the suction pump 600 is stopped to stop the production of the treated water. At this time, the blower 341 may be intermittently operated to allow the aeration to be discharged into the case 320 of the membrane module 300 through the blower pipe 342 and the diffuser 340. The discharge time of the aeration can be controlled by some or all of the hollow fiber membrane 330 cleaning process by evaluating the cleaning efficiency of the hollow fiber membrane 330, the discharge cycle of the aeration can be controlled as well.

As shown in FIG. 4B, the circulating flow of the upper water layer in the hollow fiber membrane 330 cleaning process may be deeper than the circulating flow of the upper water layer generated in FIG. 4A due to the strong lifting force caused by the aeration.

Therefore, the height of the sludge deposited on the basis of the minimum depth of the circulating flow of the hollow fiber membrane 330 cleaning process can be reduced as much as the disturbance caused by the sludge.

Sludge Disposal

Hereinafter, referring to FIG. 4C, the waste disposal process of the sludge will be described in detail.

When the filtration process of the water 10 to be treated through the membrane module 300 according to the present invention is the amount of sludge is increased due to the continuous precipitation of the sludge, the turbidity meter 230 detects this, than the predetermined value If turbidity increases, the sludge disposal process proceeds.

The sludge disposal process may be summarized as the sludge is discharged to the sludge waste line 540 by the operation of the sludge waste pump 520 located in the sludge collection hopper 510 connected to the bottom of the sedimentation membrane separation tank 200.

Operating the stirrer 220 located below the settling membrane separation tank 200 by agitation strength and time set to effectively move the strong sludge under the settling membrane separation tank 200 around the sludge waste pump 520. desirable.

The sedimentation membrane separation tank 200 is lowered during the sludge disposal process, so that the minimum depth of the sedimentation membrane separation tank 200 should be set during the sludge disposal process so that the membrane module 300 is not exposed by the drainage. Accordingly, the maximum sludge waste volume per ash should also be limited in relation to the minimum depth set in the water level gauge 240.

In addition, the blower 341 may be operated to clean the hollow fiber membrane 330 even during the sludge disposal process.

Sludge waste volume of the one settling membrane separation tank 200 may be calculated by the method of Equation 1 below as measured by the turbidimeter 530 or MLSS measuring system (not shown).

If the sludge concentration of the settling membrane separation tank 200 is about 100 times higher than the sludge inflow concentration, the sludge waste volume of the one settling membrane separation tank 200 is about 1% of the inflow of the settling membrane separation tank 200 (recovery rate). 99%), the turbidity of the upper water layer is very good water quality of less than 10NTU.

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.

10: water to be treated
100: mixed flocculation tank
120: stirrer
130: Turbidimeter
200: sedimentation membrane separation tank
210:
220: stirrer
230: Turbidimeter
240: water gauge
300: separator module
310: housing
311: inlet
320: case
321: outlet
322: hollow fiber adhesive
330: hollow fiber membrane
340: diffuser
341 blower
342 blower pipe
351: treated water storage unit
352 treated water discharge
410: flocculation chemicals
420: inline mixer
510: Sludge Collection Hopper
520: Sludge Disposal Pump
530: Turbidimeter
540: Sludge Disposal Line
600: Suction Pump

Claims (11)

A mixed agglomeration tank in which the inflowed treated water is mixed with the agglomerated chemical and aggregated; And
Sedimentation membrane separation tank in which the sludge of the treated water mixed and agglomerated in the mixing agglomeration tank is precipitated and the membrane module is immersed.
Including;
The membrane module is arranged vertically in the sedimentation membrane separation tank, characterized in that the lower end is closed so that the inflow of the water to be treated only to the inlet of the top of the membrane module,
Water treatment device.
The method of claim 1,
And a partition wall immersed in the precipitation membrane separation tank so that sludge of the treated water mixed and aggregated in the mixing agglomeration tank is precipitated,
The partition wall is characterized in that located between the mixing flocculation tank and the membrane module,
Water treatment device.
The method of claim 1,
Wherein the separator module comprises:
A cylindrical housing having upper and lower portions open;
A case housed in the housing;
A hollow fiber membrane accommodated in the case; And
A diffuser located below the case
/ RTI >
Characterized in that a plurality of membrane modules are immersed in the precipitation membrane separation tank,
Water treatment device.
The method of claim 1,
An agglomeration chemical tank for accommodating and providing the agglomerated chemical to be introduced into the treated water; And
In-line mixer in which the flocculating chemicals provided in the flocculating chemicals tank and the inflowed treated water are mixed
Lt; RTI ID = 0.0 > 1, < / RTI &
Water treatment device.
The method of claim 1,
Further comprising a stirrer located in the lower portion of the precipitation membrane separation tank,
Water treatment device.
The method of claim 1,
Further characterized in that it further comprises a sludge collection hopper connected to the bottom of the sedimentation membrane separation tank,
Water treatment device.
The method according to claim 6,
Further comprising a sludge waste pump located within the sludge collection hopper,
Water treatment device.
The method of claim 1,
A plurality of the mixing coagulation tank is located, characterized in that it further comprises a stirrer immersed in the mixing coagulation tank,
Water treatment device.
3. The method of claim 2,
Further comprising a turbidimeter and a water gauge immersed in the precipitation membrane separation tank,
The turbidimeter and the water gauge are positioned between the partition wall and the separator module.
Water treatment device.
(a) a step of injecting a flocculating agent into the inflowed treated water to mix and agglomerate the inflowed treated water;
(b) precipitating sludge of the mixed and agglomerated treated water; And
(c) filtering the upper water layer of the water to be treated in which the sludge is precipitated by a membrane module;
Including;
Step (b) and step (c) is characterized in that in one tank,
Water treatment method.
11. The method of claim 10,
After the step (c)
(d) aspirating the treated water filtered at the top of the membrane module
Lt; RTI ID = 0.0 > 1, < / RTI &
Water treatment method.

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