KR102043280B1 - A biological pretreatment apparatus containing disk filter and a separation method therewith - Google Patents

Abstract

The present invention relates to a biological pretreatment apparatus including a mixing tank and a disk filter unit, wherein a disk filter is used in place of a solid-liquid sedimentation separator used to separate sludge adsorbed with organic matter formed in the mixing tank. It is characterized in that to separate the sludge adsorbed by the organic matter, by using a disk filter instead of the conventional sedimentation separation tank, it is possible to reduce the size of the solid-liquid sedimentation separation apparatus used in the conventional separation tank, By controlling to selectively apply a disk filter having a variety of pore sizes, it is possible to improve the separation efficiency of the sludge adsorbed organic matter.

Description

A BIOLOGICAL PRETREATMENT APPARATUS CONTAINING DISK FILTER AND A SEPARATION METHOD THEREWITH}

The present invention relates to a biological pretreatment apparatus (mixing tank and separation tank), which uses a disk filter in place of the solid-liquid sedimentation separation unit being used to separate the sludge adsorbed organic matter formed in the mixing tank. Isolate the sludge adsorbed organic matter.

In addition, the biological pretreatment apparatus according to the present invention can not only reduce the size of the solid-liquid settling separation apparatus used in the conventional separation tank by adding a disk filter to the rear end of the existing separation tank, but also have a disk filter having various pore sizes. By controlling to selectively apply, the separation efficiency of the sludge to which the organic substance is adsorbed can be improved.

In addition, the separated organic sludge can be recycled back to the mixing tank to maintain high coagulation efficiency, and the amount of organic matter adsorbed on the sludge is measured by measuring the chemical oxygen demand (COD) or the biological oxygen demand (BOD) of raw water in the mixing tank in advance. By grasping in advance, the pore size of the disk filter used can be changed in various ways, and the sludge separation efficiency can be optimized.

Due to the industrial development, rapid development has been made in various technical fields, but this has led to an increase in the discharge of sewage containing various pollutants, such as agricultural and industrial wastewater, industrial wastewater, industrial wastewater, and household sewage. Environmental pollution is an important issue.

These various sewage causes pollution of public waters such as inner bay and inland sea and urban small and medium rivers.In particular, in recent years, due to rapid industrial development, population increase and population concentration of cities, In waste water, the proportion of inorganic and organic components is gradually increasing.

These wastewaters contain high concentrations of organic substances such as chemical oxygen demand (COD), biochemical oxygen demand (BOD), suspended solids (SS), nitrogen, and phosphorus, and if they flow into rivers, lakes, dams, etc., they cause pollution of water resources such as eutrophication. This, of course, leads to the destruction of the ecosystem due to toxicity and adversely affects the environment. Therefore, the wastewater is set to a predetermined standard, and is purified to drain below a predetermined standard value.

On the other hand, conventional treatment methods for removing suspended particles in the wastewater during water treatment of the wastewater include chemical treatment, electrical treatment, filtration, membrane (membrane) method, the most typical treatment method is a coagulant in chemical treatment ), The use of inorganic or organic coagulants to change the surface properties of the particles to form a floc (floc) is known to be the most common method until now.

The basic procedure of the chemical treatment method using such a flocculant is as follows. First, a coagulation step of neutralizing colloid in sewage, which is treated water, using a metal salt (generally iron or aluminum compound) to generate a micro floc, followed by a floc forming step of collecting and growing the micro floc. This can be done by adding a polymer to the microflux produced in the flocculation step. Thereafter, a step of generating treated purified water is performed by separating sludge produced by precipitation of flocs from the water to be treated.

Chemical treatment methods using such flocculants are important to improve the quality of the floc so that floc formation, growth and sludge production are carried out efficiently, by reducing the capacity of the overall sewage treatment plant, including the mixing and sedimentation tanks. This is directly related to cost savings and maintenance / reduction costs. Therefore, there is a demand for a technique capable of achieving an excellent water treatment effect such as a reduction in facility cost by improving the conventional chemical treatment method.

Patent Application Publication No. 10-1145049

The present invention is to solve the problems of the prior art as described above, in order to separate the sludge adsorbed organic matter formed in the mixing tank, it is easy to operate in place of the conventional solid-liquid sedimentation separator A semi-permanent disk filter is used to separate the sludge adsorbed with organic matter.

In addition, by applying the disk filter unit to the biological pretreatment device, it is possible to effectively reduce the hydraulic residence time and land area compared to the conventional sedimentation separation device, and to adjust the pore size of the disk filter included in the disk filter unit Accordingly, the present invention provides a biological pretreatment apparatus and a method of operating the same while flexibly controlling hydraulic retention time, sludge moisture content, and the like.

These and other objects and advantages of the present invention will become apparent from the following description of preferred embodiments.

In one embodiment of the present invention for solving the problems of the prior art, the biological pretreatment apparatus includes a receiving space for receiving the water to be treated; An inlet for supplying the water to be treated to the accommodation space; and an outlet for discharging the water to be treated contained in the accommodation space to the outside, wherein the organic contaminants contained in the water to be treated are grown as flocs to form sludge. Mixing tank to do; And a disk filter unit separating the sludge contained in the water to be treated discharged through the discharge port of the mixing tank.

The disk filter unit preferably has a pore size of 25 to 200 mm in pore size, and more preferably includes at least one disc filter having different pore sizes.

The mixing tank may further include a detection unit for measuring the COD or BOD of the water to be supplied, including sludge discharged from the mixing tank according to the COD or BOD value of the water to be measured by the detection unit. The water to be treated may be supplied to at least one disk filter included in the disk filter unit.

The treated water including the sludge supplied to the disk filter unit is solid-liquid separated through the disk filter to form a cake layer on the surface of the disk filter. The sludge formed as a cake layer on the surface of the disk filter is subjected to biological pretreatment. As it progresses, the thickness increases as the cake layer formed on the surface of the disk filter increases.

Such an increase in the thickness of the cake layer on the surface of the disc filter causes an increase in the pressure difference between the disc filters, so that when the increase in the differential pressure reaches about 20%, it is treated by the disc filter. It is preferable to supply backwash water in a direction opposite to the direction in which the water is treated to desorb the sludge forming the cake layer formed on the surface of the disc filter.

It is more preferable that the sludge desorbed by the backwash water is recovered again into the mixing tank.

In order to form sludge by growing organic contaminants contained in the water to be treated with a floc, the mixing tank includes a stirrer capable of stirring the incoming water to be treated, and preferably includes at least two in the mixing tank. More preferably.

In addition, the stirrer may use an impeller type having a wing shape, it may be further provided with a porous plate having a cavity having a diameter of 3 ~ 5cm between the plurality of stirrers.

Optionally, a sedimentation tank may be additionally installed between the mixing tank and the disk filter unit, in which the sludge separated during solid-liquid separation of the sludge in the subsequent disk filter unit by pre-settling part of the sludge produced in the mixing tank. By reducing the amount of, the backwash cycle can be reduced.

In another embodiment of the present invention, there is a biological pretreatment method, comprising: an inflow step of supplying treated water to a mixing tank including an accommodation space for receiving treated water; Forming sludge by growing organic contaminants contained in the water to be treated in a floc in the mixing tank; A discharge step of discharging the water to be treated containing sludge from the mixing tank; And a solid-liquid separation step of supplying the discharged water to be treated to the disk filter unit to separate sludge contained in the water to be treated.

The disc filter unit may include a plurality of disc filters having different pore sizes, and the pore size may have a pore size range of 25 to 200 mm.

The mixing tank further includes a detection unit for measuring COD or BOD, to measure the COD or BOD of the water to be supplied in the inflow step, wherein the discharge step, the blood to be measured in the detection unit The treated water including the sludge discharged from the mixing tank is supplied to at least one disk filter included in the disk filter unit according to the COD or BOD value of the treated water.

In the solid-liquid separation step, the liquid to be treated including the sludge supplied to the disk filter unit is solid-liquid separated through the disk filter in the disk filter unit, during which a cake layer is formed on the surface of the disk filter.

After the solid-liquid separation step, by supplying a backwash water to the disk filter, a recovery step of desorbing the sludge formed as a cake layer on the surface of the disk filter to recover to the mixing tank; further preferably, if necessary As such, between the discharge step and the solid-liquid separation step, the precipitation step of precipitating a portion of the sludge through the settling tank; may be added.

The biological pretreatment device according to the present invention can not only reduce the size of the solid-liquid settling separation device used in a conventional separation tank by adding a disk filter to the rear end of an existing separation tank, but also select a disk filter having various pore sizes. By controlling the application, the efficiency of separation of the sludge adsorbed with organic matter can be improved, and the cost can be reduced by initial investment, automatic operation, and semi-permanent use.

In addition, the separated organic sludge can be recycled back to the mixing tank to maintain high coagulation efficiency, and the amount of organic matter adsorbed on the sludge is measured by measuring the chemical oxygen demand (COD) or the biological oxygen demand (BOD) of raw water in the mixing tank in advance. By grasping in advance, the pore size of the disk filter used can be changed in various ways, and the sludge separation efficiency can be optimized.

However, the effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a schematic of a conventional biological pretreatment device.
Figure 2 schematically shows a biological pretreatment device according to an embodiment of the present invention.
3 and 4 are diagrams schematically illustrating an diffuser according to an example.
5 is a view schematically showing a mixing tank equipped with a stirrer and a porous plate according to an example.
6 is a view schematically showing an agitator according to an example.
7 schematically illustrates a biological pretreatment apparatus including a disk filter unit according to an embodiment of the present invention.
FIG. 8 (a) schematically shows the water to be subjected to the solid-liquid separation through the disc filter, and FIG. 8 (b) schematically shows the sludge forming the cake layer on the surface of the disc filter. 8 (c) schematically shows the process of discharging the cake layer of the sludge formed on the surface of the disc filter through the backwash water.
9 is a view schematically showing a sedimentation tank according to an example.
10 (a) and 10 (b) are diagrams schematically showing an orifice tube according to an example, respectively.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to ordinary or dictionary meanings, but should be construed as meanings and concepts consistent with the technical spirit of the present invention. However, in describing the present invention, descriptions of functions or configurations already known will be omitted to clarify the gist of the present invention.

Throughout this specification, when a member is located “on” another member, this includes not only when one member is in contact with another member but also when another member exists between the two members.

Throughout this specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless otherwise stated.

Terms such as "first" and "second" are intended to distinguish one component from another component, and the scope of rights should not be limited by these terms. For example, the first component may be named the second component, and similarly, the second component may also be named the first component.

In addition, the drawings attached in the present specification are intended to illustrate preferred embodiments of the present invention, and together with the detailed description of the present invention serves to further understand the technical spirit of the present invention, the present invention is limited only to those described in such drawings It should not be interpreted.

1 schematically shows a biological pretreatment device 1 according to the prior art. As shown in FIG. 1, the existing biological pretreatment apparatus 1 includes a mixing tank 10 for forming and growing a contaminant contained in a flow-in treated water into a floc; And a sedimentation tank 20 for discharging and discharging the flux introduced from the mixing tank 10 in a sludge form.

In the mixing tank, adsorption of organic matter using activated sludge and flocculant (Fe or Al) is performed, and in the precipitation tank, a process of solid-liquid separation of sludge to which organic matter is adsorbed is carried out. There are problems of increase in residence time, land area, initial investment cost and operation cost.

To solve the problem of such a conventional biological pretreatment device (which is not meant to mean that the prior art or biological pretreatment device referred to in the prior art is known before the application of the present invention) A biological pretreatment device 100 in accordance with one embodiment of the present invention is shown schematically in FIG. 2.

The biological pretreatment device 100 includes an accommodation space 101 for receiving the water to be treated; And an inlet port 102 for supplying the water to be treated into the accommodation space 101; and an outlet 103 for discharging the water to be treated contained in the accommodation space 101 to the outside. A mixing tank 200 for growing sludge to form sludge by forming organic contaminants; And a disk filter unit 300 separating the sludge contained in the water to be treated discharged through the discharge port 103 of the mixing tank 200.

The mixing tank 200 forms and grows contaminants contained in the inflowed treated water into flocs, and the flocks generated in the mixing tank 200 are sludge-formed in the treated water discharged through the outlet 103. Is included in the solid phase of the present invention, and the treated water including the sludge-like solid phase in the mixing tank 200 is not a conventional settling tank disk filter unit 300 Solid-liquid separation).

The mixing tank 200 may further include an acid generator 150 at the bottom to form a floc and grow the contaminants contained in the water to be treated supplied into the mixing tank 200. The diffuser 150 may perform a function of supplying bubbles into the accommodation space 101 of the mixing tank 200. When the bubbles are supplied into the accommodation space 101, the microorganisms are extracellular polymerized materials (Extracellular). Polymeric Substance (EPS), and organic matter and suspended solids (SS) are adsorbed onto the floc or sludge. Through this, it is possible to effectively recover the organic matter, and to maximize the production of methane gas in the subsequent processes (biological treatment process, B-stage, etc.) that follows.

The diffuser 150 may be divided into a saturator type diffuser and a mixer type diffuser. The saturator type diffuser includes a pressure dispensing chamber 111 therein, and an air supply pipe 113 and a water supply pipe. The saturator 112 connected to the 114, the pump 115 for supplying water to the saturator 112 through the water supply pipe 114, the high pressure air to supply the saturator 112 through the supply pipe 113 It may include a spray nozzle 118 connected to the saturator 142 through the compressor 116 and the discharge pipe 117 to spray air dissolved water to the outside to form bubbles. Injection nozzle 118 is installed in the mixing tank 200, a plurality of may be installed, a pair of injection nozzle 118 is installed so as to face each other to collide with the sprayed bubbles to form a micro bubble. It is preferred to (see FIG. 3).

The mixer-type diffuser is connected to a supply pipe 121 through which air and water are mixed and supplied, so as to accommodate the bubble water supplied from the pump 122 and the pump 122 that form bubble water through pumping. It may include a spray nozzle 126 connected to the mixer 124 through the mixer 124 and the discharge pipe 125 having the mixing chamber 123 therein to spray the bubble water to the outside to form bubbles. Injection nozzle 126 is installed inside the mixing tank 200, a plurality of may be installed, a pair of injection nozzles 126 are installed so as to face each other to collide with the sprayed bubbles to form a micro bubble. It is preferred to be (see FIG. 4).

In one embodiment, the mixing tank 200 may further include a stirrer 130 for stirring the incoming water to be treated, the stirrer 130 to agitate the water to be treated to contaminate the water contained in the water to be treated. Allow material to grow to floc (see FIG. 5).

The stirrer 130 is preferably an impeller type having wings, but the specific shape of such an impeller stirrer 130 is not particularly limited, but preferably, the outer wing 132 has an inner wing ( 131 may be formed to be bent toward the lower direction, through which it is possible to maximize the agitation effect by allowing water to be pushed out as much as possible in the desired direction as if the water is pushed together by hand to collect water. Reference).

In addition, the stirrer 130 may be provided in plural in the mixing tank 200. When there are a plurality of agitators 130, the blade diameters of the plurality of agitators 130 may be the same or different, but the plurality of agitators 130 having different wing diameters may be lowered from the mixing tank 200 above the mixing tank 200. It is preferable to arrange the diameter to be smaller toward the side, because the inflow of the treated water flows from the upper portion to the lower portion of the mixing tank 200 to increase the flocculation efficiency due to the faster mixing speed.

At this time, the rotation speed (G-value) of the blade of the stirrer 130 is not particularly limited, and may be appropriately selected according to the mixing and flocculation scale or the size of the mixing tank 200, but preferably 30 to 110 sec ^-1. More preferably, the rotation speed of the stirrer 130 having the largest blade diameter among the plurality of stirrers 130 is 70 to 110 sec ⁻¹ , and the rotation speed of the stirrer 130 having the smallest blade diameter is 30 to 50 sec ⁻ Can be ¹

In one embodiment, the mixing tank 200 may be provided with at least one porous plate 140 between the plurality of stirrers 130, in the case of one stirrer 130, the lower portion of the stirrer 130 The porous plate 140 may be provided. At this time, the plurality of cavities formed in the porous plate 140 is not particularly limited, but can be variously selected depending on the size of the porous plate 140, the size of the mixing tank 200, etc., it has a diameter of 3 ~ 5cm desirable.

In one embodiment, the mixing tank 200 may have a plate-shaped baffle therein, and growth may be promoted when the flocks collide with the baffle. The number of baffles is not particularly limited, but at least three of the baffles are preferably formed on one wall of the mixing tank 200 for the flocculation coarsening effect.

In one embodiment, the mixing tank 200 may include a control means for controlling the stirring speed of the stirrer 130 according to the internal temperature and the amount of the formed floc. In this case, the control means detects at least one or more of a temperature sensor for measuring the upper and lower temperatures in the mixing tank 200, a particle counter for calculating the amount of floc, and a detector capable of measuring the BOD or COD of the water to be treated. It is preferable to operate in connection with the means.

The detection means included in the mixing tank 200 is connected to the control unit to select a disk filter having an appropriate pore size among the plurality of disk filters existing in the disk filter unit 300 to be described later, and the solid-liquid separation process may be performed. Can be driven.

In one embodiment, the mixing tank 200 is a flocculant supply unit (not shown) for supplying a flocculant including salt, a polymer material and the like to induce the floc formation and growth to the mixing tank 200 ) May further include. The flocculant used in the present invention is a material having a relatively low molecular weight, and serves as a floc seed to form a floc by combining with organic particles or inorganic particles in the water to be treated.

Salts included in the flocculant include aluminum (Al) or iron (Fe) -based metal salts (Al ₂ (SO ₄ ) ₃ , Fe ₂ (SO ₄ ) ₃ , FeCl ₃ , Al ₂ (OH) ₃ Cl ₂ ). Etc.), and more preferably an iron salt (FeM _n ) such as FeCl ₃ . Polymer materials included in the flocculant include polyaluminum chloride ([Al ₂ (OH) _n Cl ₆ -n] _n ), polyaluminum sulfate silicate, PASS, and Al _a (OH) _b. (SO4) _c (SiO ₂ ) _d (H ₂ O) _x ), Polyaluminum (hydroxide) chloride silicate, PACS, AlNa _x Si _y (OH) _z Cl _b ), Polyamine and Poly At least one or more of acrylamide (PAM) may be used, and in particular, it is preferable to include an anionic polymer material, which is effective for promoting flocculation, sedimentation and filtration.

In addition, an acogel which is an inorganic flocculant such as aluminum salts and iron salts such as aluminum oxide, ferrous sulfate, ferric sulfate, ferric chloride and polyaluminum chloride (PAC), a polymer flocculant, and an MT aqua polymer cationic polymer gel. Particles composed of cationic polymers that swell in water and substantially insoluble in water, such as C, may be used alone or in combination.Ammonia Oxidizing Archaea (AOA), Ammonia Oxidizing Bateria (AOB), and Nitride Oxidizing Bacteria (NOB) Biological flocculents including one or more selected from the group consisting of can also be used.

In addition, a flocculent aid may be additionally added together with such a flocculant, and the flocculent aid that may be used may be appropriately selected from the group consisting of clay, calcium hydroxide, cationic flocculant, anionic flocculant and nonionic flocculant.

The treated water that has passed through the mixing tank 200 may be supplied to the anaerobic digester after the sludge is solid-liquid separated through the disk filter unit 300. In the anaerobic digestion tank, anaerobic digestion of the ammonium-containing treated water generated in the anaerobic digestion tank using anaerobic ammonium-oxidizing bacteria (Anammox) is carried out through a continuous batch reactor for separating only the bacteria.

In the disc filter unit 300, a plurality of disc filters having various pore sizes may be arranged and used in series or in parallel. The pore sizes of such disc filters may be selected within a size range of 25 to 200 mm.

In an embodiment, the disk filter unit 300 is configured such that disk filters 301, 302, and 303 having different pore sizes are connected in parallel, as shown in FIG. 7, and then the water to be treated in the mixing tank 200. Receive a signal from the detection device 401, such as a particle counter that is located inside the receiving space 101 to calculate the amount of flocks contained in the water to be treated or a detector capable of measuring the BOD or COD of the water to be treated. The valve 402 may be controlled through the controller 400 to supply the water to be treated to the disk filter having an appropriate pore size.

For example, a disk filter unit 301 having a pore size of 25 to 50 mm, a disk filter 302 of 50 to 100 mm, and a disk filter 303 of 100 to 200 mm are provided with a disk filter unit 300 connected in parallel. When the amount of organic pollutants contained in the water to be treated supplied to the water treatment space 101 of the mixing tank 200 is small, the value of BOD or COD detected by the detection device 401 is low. Since the size of the floc in which the organic pollutants are grown or the sludge formed is relatively small, the control unit 400 may also pore the treated water discharged from the mixing tank 200 in the disc filter unit 300. The disk filter 301 is supplied with a relatively small size.

As the water quality detecting device 401 of the water to be treated, it is also possible to use not only the BOD or COD detector, but also a particle counter that directly measures the amount of floc formed.

In this way, by measuring the amount of the treated water supplied to the mixing tank or the flocs generated in the mixing tank and selecting the size of the disk filter to be solid-liquid separated in a subsequent process, the solid-liquid separation process can be performed more effectively.

8 illustrates a disk filter in which the solid-liquid separation process is performed in more detail. As shown in FIG. 8, the treated water including the sludge supplied to the disk filter 301 is solid-liquid separated through the disk filter 301 to form a cake layer 310 on the surface of the disk filter.

As the sludge is formed on the surface of the disk filter 301 as a cake layer, cake filtration may be performed on the surface of the disk filter, thereby enabling more precise filtration and solid-liquid separation than the actual pore size. . Therefore, the formation of the initial cake layer on the surface of the disc filter becomes very important. As described above, the role of the controller for selecting a disc filter having an appropriate size of pores according to the concentration and amount of floc sludge supplied is very important. do.

As the filtration by the sludge cake layer proceeds, the pressure difference (rP) applied to the disk filter gradually increases, but when it increases to about 20%, it is preferable to perform backwashing for stable operation of the process. When the backwash water is supplied to the disk filter in the direction opposite to the inward direction through which the treated water passes through the disk filter, the sludge formed on the surface of the disk filter as shown in FIG. By desorption.

At this time, it is preferable to recover at least a part of the sludge desorbed to the mixing tank again without waste. By supplying the desorbed sludge back to the mixing tank 200, it is used for the formation and growth of the flocs, thereby improving the quality and quality of the flocs. This is because the formation of flocs and sludge growth time can be reduced. In addition, it is also possible to obtain the effect of reducing the overall sludge emissions by conveying all or part of the sludge to the mixing tank 100 to circulate.

If necessary, a precipitation tank 600 of the type shown in FIG. 9 may be further configured between the mixing tank 200 and the disk filter unit 300 constituting the biological pretreatment apparatus according to the present invention. In this case, it is possible to operate the sedimentation tank of a relatively small scale compared to the sedimentation tank according to the prior art described in FIG. 1, and can reduce the amount of sludge of solid-liquid separation performed in the disk filter unit 300. Thus, the backwashing period for desorbing the sludge formed on the surface of the disc filter can be reduced.

That is, the sedimentation tank 600 is introduced into the water to be treated including the floc from the mixing tank 100, and discharged by sedimenting a portion of the introduced floc in the form of sludge, and the disk to see the treated water including the remaining flocs It is for supplying to the filter unit 300, The lower part is provided with the sludge discharge port 605 for discharging sludge (refer FIG. 9). Precipitation tank 600 is not particularly limited, but the overall appearance is in the shape of a cylinder or square column, the lower portion is preferably formed to be inclined toward the vertical central axis so that the sludge is discharged to the outside.

In one embodiment, the settling tank 600 may include a circular orifice tube 610 at the bottom in order to effectively precipitate the floc in the form of sludge. Here, the circle is a concept that includes an oval in a round form. Orifice tube 610 may have a plurality of orifice holes 611. That is, when the floc guided downward along the inner wall 601 of the settling tank 600 reaches the circular orifice tube 610, the sludge discharge port 605 passes through the orifice hole 611 at high speed to settle into the sludge. Can be discharged through.

More specifically, the flow rate Q, which is a quantity that flows over a constant area for a certain time, can be expressed as the product of the pipe cross-sectional area A and the flow rate v, in which a plurality of flocs are formed in the circular orifice tube 610. When passing through the orifice hole 611, the flow rate is the same, but as the cross-sectional area (orifice area) decreases rapidly, the speed becomes very large. Thus, the flocs settle and discharge into the sludge while passing through the orifice hole 611 at a very high speed.

In one embodiment, the circular orifice tube 610 may be one or more than two or more, and the number thereof is not particularly limited, and may be appropriately selected according to the size of the settling tank 600 or the amount of raw water to be settled. have. Preferably, it may be two to three. When there are a plurality of circular orifice tubes 610, the average diameter of each orifice tube 610 may be the same or different, more preferably a plurality of circular orifice tubes 610 having a different average diameter of the settling tank 600 The sludge settling rate can be further improved by arranging the diameter to be smaller from the upper side to the lower side. Here, the average diameter of the circular orifice tube 610 means the average length of the string passing through the center of the orifice tube 610.

In one embodiment, the inside of the circular orifice tube 610 may include a branch tube (612). The branch pipe 612 may include a plurality of orifice holes 611. The branch pipe 212 is not particularly limited in shape, but may be disposed radially from the center in the circumferential direction. That is, as shown in FIG. 10 (a), the inside of the circular orifice tube 610 is divided into three, or as shown in FIG. 10 (b), inside the circular orifice tube 610. It may be in a radially alternating form.

In one embodiment, the sedimentation tank 600 may include a bending plate 620 to prevent the injuries of the sludge. The bending plate 620 may be manufactured in various forms, but in order to effectively prevent injuries of the sludge, it is preferable that the bent plate 620 has a cone shape having a “L” shape.

In one embodiment, the settling tank 600 may include a baffle 602 provided at a predetermined distance from the inner wall 601. When the treated water including the floc is supplied between the inner wall 601 and the baffle 602 of the settling tank 600, the fluid including the floc moves under the settling tank 600 by gravity. At this time, the floc is blocked by the installed baffle 602 to move to the upper or central portion of the settling tank 600, the flow direction can be stably guided to the lower side along the inner wall (601). At this time, clean water from which the floc has been removed may be discharged through the top of the settling tank 600.

In one embodiment, the settling tank 600 may include a guide plate 603 between the inner wall 601 and the baffle 602. The guide plate can minimize resuspension of the sludge settled by dispersing the flow of fluid (treated water) containing the flocs. The number of the guide plates 603 is not particularly limited, but may be one to three.

In addition, the end of the baffle 602 may be provided with an inclined plate 604 so that the floc or sludge can be stably directed to the circular orifice tube 610 side without rising to the top of the settling tank 600. At this time, the inclined direction of the inclined plate 604 is preferably the end of the inclined plate 604 toward the center of the settling tank 600.

Next, a biological pretreatment method of the water to be treated to improve the separation performance of the organic material will be described. In describing the biological pretreatment method, for convenience of description, the biological pretreatment device 100 described above will be described, but is not limited thereto. In addition, redundant descriptions related to the biological pretreatment device 100 will be omitted.

Biological pretreatment method according to an embodiment of the present invention, the inflow step of supplying the water to be treated to the mixing tank including a receiving space for receiving the water to be treated; Forming sludge by growing organic contaminants contained in the water to be treated in a floc in the mixing tank; A discharge step of discharging the water to be treated containing sludge from the mixing tank; And a solid-liquid separation step of supplying the discharged water to be treated to the disk filter unit to separate sludge contained in the water to be treated.

The mixing tank preferably further includes a detection unit for measuring COD or BOD, and may measure the COD or BOD of the water to be treated supplied in the inflow step.

In order to effectively form and grow the contaminants contained in the water to be treated into the mixing tank and grow into a floc, the agitator may be agitated using an agitator. In addition, when there are a plurality of stirrers, a porous plate may be provided between each stirrer. At this time, the plurality of cavities formed in the porous plate is not particularly limited, but can be variously selected depending on the size of the porous plate, the size of the mixing tank, etc., preferably having a diameter of 3 ~ 5cm.

In addition, the disk filter unit includes a plurality of disk filters having different pore sizes, it is preferable that the pore size has a pore size range of 25 ~ 200mm.

In the discharging step, the treated water including the sludge discharged from the mixing tank according to the COD or BOD value of the treated water measured by the detection unit may be supplied to at least one disk filter included in the disk filter unit. In the solid-liquid separation step, it is preferable to solidify-separate the water to be treated including sludge supplied to the disk filter unit through the disk filter in the disk filter unit, and to form a cake layer on the surface of the disk filter.

After the solid-liquid separation step, if the pressure drop (rP) applied to the disk filter increases by 20% or more, the backwash water is supplied in a direction opposite to the direction in which the water to be treated is supplied, so that a cake layer is formed on the surface of the disk filter. It is preferable to detach | desorb the sludge formed in this way, and it is preferable to collect | recover at least one part of this desorbed sludge to a mixing tank.

Thus, a part of the sludge desorbed through backwashing is fed back into the mixing tank 200 to be used for the formation and growth of the floc, thereby forming a good floc with improved size and density. And settling time can be reduced. In addition, all or part of the sludge is returned to the mixing step to circulate to obtain an effect of reducing the overall sludge emissions.

In addition, by injecting bubbles during the growth of the floc to promote the secretion of Extracellular Polyeric Substance (EPS) of the microorganisms, it is possible to efficiently recover the organic matter by adsorbing the organic and SS (suspension) components to the sludge, The effect of improving the production of methane gas in the biological treatment step can also be obtained.

Optionally, if necessary, it is also possible to add a precipitation step of precipitating a portion of the sludge through the settling tank between the discharge step and the solid-liquid separation step.

This precipitation step is to precipitate the floc in the form of sludge and discharge it to the outside, it is preferable to pass through the orifice tube having a plurality of orifice holes in order to effectively precipitate the floc in the form of sludge. In general, the flow rate (Q), which is the amount of flow over a certain area over a period of time, can be expressed as the product of the pipe cross-sectional area (A) and the flow rate (v). When the floc passes through multiple orifice holes formed in a circular orifice tube, Is the same, but as the cross-sectional area (orifice area) decreases rapidly, the speed becomes very large. Thus, the floc can settle and discharge into the sludge while passing through the orifice hole at a very high speed.

In the process of recovering the sludge, the sludge dehydrating agent may be supplied to the sludge supplied to the mixing tank. The sludge dehydrated by the sludge dehydrating agent may increase in density, thereby growing a good floc with increased size and density of the floc in the mixing step. The sludge dehydrating agent may use a polymer material, and preferably, a cationic polymer material.

In the present specification, only a few examples of various embodiments performed by the present inventors are described, but the technical idea of the present invention is not limited thereto, but may be variously modified and implemented by those skilled in the art.

1, 100: biological pretreatment device 10, 200: mixing tank
20, 600: sedimentation tank 101: accommodation space
102: inlet 103: outlet
150: acid machine 111: pressure dissolved chamber
112: saturator 113: air supply pipe
114: water supply pipe 115: pump
116: compressor 117: discharge pipe
118: injection nozzle 121: supply pipe
122: pump 123: mixing chamber
124 mixer 125 discharge pipe
126: injection nozzle 130: agitator
131: inner wing portion 132: outer wing portion
140: porous plate 142: saturator
300: disc filter unit 301, 302, 303: disc filter
400: control unit 401: detection device
601: inner wall 602: baffle
603: guide plate 604: inclined plate
605: sludge outlet 610: orifice tube
611: orifice hole 612: branch pipe
620: bending plate

Claims (17)

An accommodation space for receiving the water to be treated; An inlet for supplying the water to be treated to the accommodation space; and an outlet for discharging the water to be treated contained in the accommodation space to the outside, wherein the organic contaminants contained in the water to be treated are grown as flocs to form sludge. Mixing tank to do;
A disk filter unit separating the sludge contained in the water to be treated discharged through the discharge port of the mixing tank;
Located in the mixing tank, the detection unit for measuring the COD or BOD of the water to be supplied; And
Located in the lower portion of the mixing tank, the saturator type diffuser or mixer type diffuser for supplying bubbles into the receiving space of the mixing tank; includes,
The disk filter unit includes at least two parallel connected disk filters having different pore sizes, and includes the sludge discharged from the mixing tank according to the COD or BOD value of the treated water measured by the detector. It is supplied to any one disk filter of two or more parallel connected disk filter included in the disk filter unit,
The water to be treated containing the sludge supplied to the disk filter unit is solid-liquid separated through the disk filter to form a cake layer on the surface of the disk filter,
Sludge formed as a cake layer on the surface of the disk filter, characterized in that the desorbed by the backwash water supplied to the disk filter is recovered to the mixing tank. The method of claim 1,
The disk filter unit, the biological pretreatment device, characterized in that the pore size has a pore size of 25 ~ 200mm. delete delete delete delete The method of claim 1,
And a stirrer capable of stirring the incoming water to be treated in the mixing tank. The method of claim 7, wherein
The at least two agitators are provided in the mixing tank, characterized in that the impeller type having a wing shape, biological pretreatment device. The method of claim 8,
Biological pretreatment device, characterized in that provided; a porous plate formed with a cavity having a diameter of 3 ~ 5cm between the stirrer. The method of claim 1,
Biological pretreatment device, characterized in that the precipitation tank is additionally installed between the mixing tank and the disk filter unit. An inflow step of supplying the water to be treated to the mixing tank including an accommodation space for receiving the water to be treated;
Forming sludge by growing organic contaminants contained in the water to be treated in a floc in the mixing tank;
A discharge step of discharging the water to be treated containing sludge from the mixing tank;
A solid-liquid separation step of separating the sludge contained in the treated water by supplying the discharged treated water to a disk filter unit including at least two parallel connected disk filters having different pore sizes; And
After the solid-liquid separation step, by supplying backwash water to the disk filter, a recovery step of desorbing the sludge formed as a cake layer on the surface of the disk filter to recover to the mixing tank;
The mixing tank further includes a detection unit for measuring COD or BOD, to measure the COD or BOD of the water to be supplied in the inflow step,
Supplying bubbles into the accommodation space of the mixing tank through the saturator-type diffuser or mixer-type diffuser located in the lower portion of the mixing tank,
The discharging step may include any one of a disk filter connected in parallel to a disk filter included in the disk filter unit, the treated water including the sludge discharged from the mixing tank according to the COD or BOD value of the water to be measured by the detection unit. Supplied by
The solid-liquid separation step, characterized in that the solid-liquid separation of the treated water including the sludge supplied to the disk filter unit, the disk filter in the disk filter unit, to form a cake layer on the surface of the disk filter, biological pretreatment Way. delete delete delete delete delete The method of claim 11,
Between the discharge step and the solid-liquid separation step, the precipitation step of precipitating a portion of the sludge by passing through a settling tank; characterized in that the added, biological pretreatment method.

Images