KR20200062010A - Treatment System of The Wastewater Containing Silica Capable of removing nitrogen and Phosphorus - Google Patents

Abstract

The present invention relates to an apparatus for processing silica-containing wastewater capable of simultaneously processing nitrogen and phosphorus, which comprises: a first gravitational precipitation tank (10) receiving the silica-containing wastewater to firstly precipitate and remove silica; a second gravitational precipitation tank (20) installed at the rear end of the first gravitational precipitation tank and precipitating and removing the remaining silica included in the processed water; an aerobic membrane separation tank (30) installed at the rear end of the second gravitational precipitation tank and aerating the inflow processed water to perform solid-liquid separation and nitrification of the processed water; a deaeration tank (40) installed at the rear end of the aerobic tank to reduce dissolved oxygen included in the inflow processed water; and a reaction tank (50) receiving the processed water transferred from the deaeration tank to denitrify nitride and nitrogen included in the processed water. According to the present invention, the apparatus can effectively process silica generated from a semiconductor, particularly a wafer process, and can simultaneously process nitrogen and phosphorous, which are nutrient salts, and organic materials included in the wastewater.

Description

{Treatment System of The Wastewater Containing Silica Capable of removing nitrogen and Phosphorus}

The present invention relates to an apparatus for treating silica-containing wastewater, and more specifically, to effectively treat wastewater containing silica generated in a semiconductor process, particularly a wafer process, as well as organic substances and nutrients contained in various sewage. The present invention relates to a treatment device for silica-containing wastewater capable of simultaneously treating phosphorus nitrogen and phosphorus.

Various methods and facilities are being researched and operated in the field for the treatment of wastewater from industrial facilities. Patent No. 0385706 may be referred to as a conventional technique for treating wastewater and sewage generated in a semiconductor manufacturing process.

The patent No. 0385706 discloses a method and system for removing silica from large amounts of wastewater. According to this method, the wastewater stream containing silica is treated with a flocculant such as an epichlorohydrin/dimethylamine polymer, producing spherical particles clumped in clusters with a diameter of 5 microns or more. At this time, the treated wastewater is passed through a microfiltration membrane that physically separates silica contaminant particles from the wastewater. Thus, commercially available microfiltration membranes having pore sizes of 0.5 microns to 5 microns can be used. The flow rate of the treated wastewater passing through the microfiltration membrane is 150 GFD (gallons per square foot of membrane per day) to 600 GFD. This should ensure that solids are removed from the surface of the membrane.

However, it is generally pointed out that the wastewater generated in the semiconductor manufacturing process has a high concentration of suspended solids (SS) and a high pressure difference due to membrane contamination in the treatment process. This phenomenon is due to silica (SiO ₂ ) discharged from the semiconductor wafer process.

However, the existing silica-containing wastewater has difficulties such as time-consuming and time-consuming in actual operation, such as the need to clean or replace using a method such as backwashing from time to time due to problems such as membrane contamination. Moreover, wastewater generated at various sites in the industrial complex includes not only wastewater containing silica, but also substances that pollute the water environment by causing eutrophication such as organic matter and nitrogen or phosphorus from various sewage, but the treatment of these pollutants Facilities cannot be solved alone, and separate treatment facilities are required. This also requires additional cost and time.

Accordingly, as well as effectively treating wastewater containing silica generated in a semiconductor process, especially a wafer process, development of a technology capable of simultaneously treating organic substances and nutrient salts nitrogen and phosphorus contained in various wastewater mixed with the wastewater This is urgently required.

[Advanced technical literature]

[Patent Document]

Domestic Publication Patent No. 10-0385706 (2003.05.16)

Accordingly, the present invention has been devised to solve the above problems, as well as effectively treating wastewater containing silica generated in a semiconductor process, particularly a wafer process, as well as organic materials and nutrients contained in various sewage. It is an object to provide a treatment device for silica-containing wastewater capable of treating phosphorus nitrogen and phosphorus simultaneously.

The technical problem of the present invention as described above is achieved by the following means.

(1) a first gravity sedimentation tank in which silica-containing wastewater is introduced to firstly remove silica; A second gravity sedimentation tank installed at a rear end of the first gravity sedimentation tank and sedimenting and removing residual silica contained in the treated water; A membrane separation aerobic tank installed at a rear end of the second gravity sedimentation tank and performing a solid-liquid separation and nitrification of the treated water by aeration treatment; A degassing tank installed at a rear end of the exhalation tank to reduce dissolved oxygen contained in the treated water introduced; And a reaction tank that receives the treated water returned from the degassing tank and performs nitrification and denitrification contained in the treated water.

(2) In the above (1),

The reaction tank is a device for treating silica-containing wastewater, which receives inflow of the treated water that has passed through the deaeration tank, and alternately operates in the order of anaerobic, aerobic, and anaerobic using an intermittent aeration method.

(3) In the above (1),

The treatment device for silica-containing wastewater is installed in parallel in a pair, and for this purpose, a distribution tank is installed at the front end of which the wastewater flows, and the distribution tank receives raw water (or treated water that has been pre-treated) from the outside and a pair of left and right. Silica-containing wastewater treatment apparatus characterized in that it is distributed to the first gravity settling tank.

(4) In the above (3),

One of the pair of reactors is set to the time of receiving the treated water in an anaerobic state from the degasser, and the other is to alternate the process cycle of the reactor by allowing the introduced treated water to perform an alternate reaction of anaerobic, aerobic and anaerobic. Silica-containing wastewater treatment device, characterized in that configured to be.

(5) In the above (3),

A treatment device for silica-containing wastewater, characterized in that a scum reservoir is disposed at the rear end of the deaeration tank to remove scum before discharge of the final treated water.

(6) In the above (1),

The reaction tank is a device for treating silica-containing wastewater, characterized in that a first reaction chamber for an anaerobic and aerobic process and a second reaction chamber for an anaerobic process are separately installed.

(7) In the above (6),

Silica-containing wastewater treatment apparatus, characterized in that a connecting conduit is disposed between the first and second reaction chambers, and a heat supply means is additionally mounted on the conduit.

(8) In the above (6),

A treatment device for silica-containing wastewater, characterized in that a vacuum pump is connected to the outside of the second reaction chamber along with a closed structure for vacuum decompression.

(9) In the above (8),

Silica-containing wastewater, characterized in that a heat supply means is installed in the connection line between the deaeration tank and the membrane separation exhalation tank to supply heat to the treated water, and a vacuum pump is connected to the outside of the deaeration tank with a closed structure for vacuum decompression. Processing device.

(10) In the above (9),

A device for treating silica-containing wastewater, wherein a baffle having a hemispherical protrusion is formed on the surface of the first gravity settling tank and the second gravity settling tank.

As described above, the device according to the present invention is a very useful and effective invention capable of effectively treating silica generated in a semiconductor, especially a wafer process, as well as simultaneously treating organic substances and nutrients nitrogen and phosphorus contained in sewage. .

1 is a view showing an apparatus for treating wastewater containing real car according to the present invention,
2 is a view showing the configuration of the gravity settling tank according to the present invention.
3 is a view showing a preferred embodiment of the reactor according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION The following detailed description, together with the accompanying drawings, is intended to describe exemplary embodiments of the present invention, and is not intended to represent the only embodiments in which the present invention may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present invention. However, one of ordinary skill in the art to which the present invention pertains knows that the present invention may be practiced without these specific details.

In some cases, in order to avoid obscuring the concept of the present invention, well-known structures and devices may be omitted, or block diagrams centered on the core functions of each structure and device may be illustrated.

Throughout the specification, when a part "comprising or including" a certain component, it means that other components may be further included rather than excluding other components, unless otherwise specified. do. In addition, the term "… part" described in the specification means a unit that processes at least one function or operation. In addition, "a (a or an)", "one (one)," "the (the)" and similar related terms in the context of describing the present invention (especially in the context of the following claims) is different herein. It may be used in a sense including both singular and plural unless indicated or clearly contradicted by context.

In describing embodiments of the present invention, when it is determined that a detailed description of known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, terms to be described later are terms defined in consideration of functions in an embodiment of the present invention, which may vary according to a user's or operator's intention or practice. Therefore, the definition should be made based on the contents throughout this specification.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a view showing a device for treating silica-containing wastewater according to the present invention, FIG. 2 is a view showing a configuration of a gravity sedimentation tank according to the present invention, and FIG. 3 shows a preferred embodiment of a reaction tank according to the present invention It is a drawing.

As shown in the figure, the apparatus 100 for treating silica-containing wastewater includes: a first gravity sedimentation tank 10 in which silica-containing wastewater is introduced to firstly remove and remove silica; A second gravity settling tank 20 installed at a rear end of the first gravity settling tank and sedimenting and removing residual silica contained in the treated water; A membrane separation aerobic tank 30 installed at a rear end of the second gravity sedimentation tank and performing a solid-liquid separation and nitrification of the treated water by abandoning the introduced treated water; A degassing tank 40 installed at the rear end of the exhalation tank to reduce dissolved oxygen contained in the treated water introduced; And a reaction tank 50 that receives the treated water returned from the degassing tank and performs nitrification and denitrification contained in the treated water.

Preferably, the silica-containing wastewater treatment apparatus 100 according to the present invention is installed in parallel in a pair. To this end, a distribution tank 60 is installed at the forefront where wastewater flows. The distribution tank 60 receives raw water (or treated water that has undergone pre-treatment) flowing from outside and distributes it to a pair of left and right first gravity sedimentation tanks 10. A pressurized flotation tank (not shown) may be installed at the front end of the distribution tank 60 for pretreatment to remove various suspended substances including oil and fat contained in the raw water in advance.

At this time, the distribution can be made in consideration of the processing capacity of each device and the operating state of the equipment, and it is desirable to be automatically controlled through a controller (not shown). For example, the distribution tank 60 controls one facility to introduce raw water to the other when a factor such as replacement or repair occurs.

A baffle 11 is formed inside the first gravity settling tank 10 to induce particles containing silica to settle by gravity. At this time, the removed silica is about 30 to 60%.

Preferably, a hemispherical protrusion (not shown) is formed on the surface of the baffle at a predetermined interval. The hemispherical protrusion prevents the formation of a cake by preventing agglomeration of suspended solids in the wastewater, thereby preventing silica from being adsorbed on the cake, and consequently, recovery or removal efficiency of silica can be improved.

The treated water that has passed through the first gravity settling tank 10 flows into the second gravity settling tank 20. The second gravity sedimentation tank 20 has a baffle 21 therein mounted on the top perpendicular to the direction in which the treated water proceeds. Therefore, most of the remaining silica particles contained in the moving water being moved are blocked by the baffle 21 and can be removed by precipitation by gravity.

The treated water that has passed through the second gravity settling tank 20 is in a state where silica particles are almost removed. Therefore, according to the present invention, it is possible to prevent contamination of the separation membrane installed in the membrane separation exhalation tank 30 installed at the rear end.

The membrane separation aerobic tank 30 performs solid-liquid separation and nitrification of the treated water, and phosphorus intake occurs therewith. The separation membrane 31 immersed in the interior is preferably a hollow fiber microfiltration membrane, and it is possible to operate the membrane for more than 6 months because it can be cleaned using only aeration air without the need for a backwashing process of water, air, or chemicals. .

In addition, in the present invention, since the hollow filtration microfiltration membrane of the suction filtration method is used in place of the existing sedimentation tank, filtration tank and disinfection tank for nitrification and phosphorus removal as described above, the operation of the process is performed at an MLSS concentration of about 7,000 to 13,000 mg/L. Since it is possible, there is no need to input additional chemicals to remove phosphorus, and stable nitrification is possible even in winter.

The deaeration tank 40 reduces dissolved oxygen contained in the treated water that has passed through the membrane separation exhalation tank 30 at the front end. The degassing tank 40 does not input a separate compressed air, and can be simply performed through stirring. Since the treated water that has passed through the membrane separation aerobic tank 30 contains a large amount of dissolved oxygen, the degassing tank 40 consumes the dissolved oxygen to oxidize and remove organic substances present in the treated water, thereby dissolving the dissolved oxygen in the treated water Is reduced.

As described above, through the reduction of dissolved oxygen by the deaeration tank 40, an anaerobic atmosphere performed in the reaction tank 50 at the rear stage is provided. Preferably, the dissolved oxygen in the treated water that has passed through the degassing tank 40 is 0.2 mg/L or less.

The treated water from the degassing tank 40 is returned to the reaction tank 50.

The reaction tank 50 receives the treated water flowing through the degassing tank 40, and is operated alternately in the order of anaerobic, aerobic, and anaerobic processes, preferably using an intermittent aeration method. Therefore, the treated water that has passed through the degassing tank 40 is first operated as an anaerobic process, and in this period, denitrification of the treated water and release of phosphorus are induced. Subsequently, the treated water is followed by an aerobic process, through which nitrification of residual nitrogen is performed. Then, the nitric acid nitrogen produced through the nitrification process undergoes denitrification and phosphorus removal in the anaerobic atmosphere again by a subsequent anaerobic process. The series of processes may be performed by a simple method of sequentially intermittent aeration in one reaction chamber.

In a preferred embodiment of the present invention, the reaction tank 50 is preferably a first reaction chamber 51 for anaerobic and aerobic processes to efficiently create an anaerobic atmosphere in the last step, and a second for the last anaerobic process. The reaction chamber 52 can be separately installed. In this case, preferably, a connecting conduit 53 is placed between the first reaction chamber 51 and the second reaction chamber 52, and a heat supply means 54 may be additionally mounted on the connecting conduit. The heat supply means may be a heat exchanger that receives heat through a heat exchange method from a high temperature fluid supplied from a heating jacket or a boiler in a form surrounding a part of the connection pipe. In addition, a vacuum pump (not shown) may be connected to the outside of the second reaction chamber 52 together with a sealed structure for vacuum decompression.

According to this configuration, since the anaerobic and aerobic reactions must continuously occur in the first reaction chamber 51, an aerobic means is required inside the first reaction chamber, and after the anaerobic reaction, aerobic reaction is performed through aeration treatment. I can do it. The treated water in which the aerobic reaction proceeds includes dissolved oxygen, which is heated by a heat supply means before entering the second reaction chamber 52 (preferably, the temperature of the treated water is raised to reach 30-40° C. ), the heated treated water is introduced into the second reaction chamber 52, so that the oxygen solubility due to temperature rise is reduced, and when the vacuum pump is operated to maintain a reduced pressure at the top, the oxygen solubility is further reduced. Most of the dissolved oxygen can be removed in a short time. Through this process, the second reaction chamber 52 may be formed as an anaerobic atmosphere in a short time.

As described above, the operation of the configuration such as the heat supply means 54 or the vacuum pump can be controlled by a controller (not shown).

Through this series of reactions, most of the nitrogen and phosphorus compounds present in the treated water can be removed. The treatment process through the reaction tank 50 can be normally operated for 60 minutes.

In the present invention, preferably, the reaction tank 50 is maintained in an anaerobic atmosphere for a time during which the treated water is introduced from the deaeration tank 40 (set to approximately 60 minutes) before initiating a series of reactions of anaerobic, aerobic and anaerobic processes. .

As a preferred embodiment of the present invention, one of the pair of reaction tanks 50 is set to a time for receiving the treated water in an anaerobic state from the degassing tank 40, and the other is an anaerobic, aerobic, anaerobic process By performing a series of reactions, it is possible to alternately perform the process cycle of the reactor.

In the present invention, since it is abandoned using the intermittent aeration method as described above, it has a self-sludge transfer effect, and thus it is possible to reduce maintenance costs.

As described above, the treated water that has passed through the reaction tank 50 flows back into the membrane separation aerobic tank 30 to oxidize and remove organic substances that may remain in the treated water, while completely removing nitrification and phosphorus. The treated water that has passed through the membrane separation aerobic tank 30 flows into the degassing tank 40 to reduce dissolved oxygen, and a part of the treated water is returned to the reaction tank 50 through a conveying line again, and the rest is scum reservoir 70 After removing the scum through, it is discharged.

Preferably, a heat supply means such as a heat jacket or a heat exchanger is placed in a connection pipe (not shown) between the degassing tank 40 and the membrane separation exhalation tank 30, and vacuum decompression is applied to the upper portion of the degassing tank 40. A vacuum pump 55 is connected to the outside together with a sealed structure for. Through this, dissolved oxygen can be almost completely reduced during a short residence time in the degassing tank, thereby improving treatment efficiency.

Hereinafter, the contents of the present invention will be described in more detail with reference to Examples. However, the exemplified examples below are only presented to help the understanding of the present invention and should not be construed as limiting the scope of the present invention.

[Example 1]

As a result of experiments on wastewater generated in the Asan Digital Industrial Complex, which is known to contain a large amount of silica using the device of the present invention, daily average TMS measurement values are shown in Table 1 below. However, 2018.04.10. and 2018.04.11. were performed according to the existing treatment method (MBR method), and the method was changed from April 12, 2018 to test using the treatment device according to the present invention shown in FIG. Was performed.

Measurement day COD T-N T-P pH SS Comparative example 2018.04.02 7.2 1.57 0.049 7.75 41.2 2018.04.11 8.3 1.42 0.049 7.82 27.7 Example 2018.04.12 9.7 1.27 0.049 7.93 5.4 2018.04.21 6.8 1.26 0.031 7.84 0.5

As described above, it can be confirmed that the existing MBR method alone does not effectively remove the suspended solids (SS) containing silica, whereas the improved method according to the present invention confirms that the silica is completely removed.

10: first gravity sedimentation tank
20: second gravity sedimentation tank
30: membrane separation aerobic tank
40: degasser
50: reactor
60: distribution tank
70: scum storage tank

Claims (3)

A first gravity sedimentation tank in which silica-containing wastewater is introduced to firstly remove silica; A second gravity sedimentation tank installed at a rear end of the first gravity sedimentation tank and sedimenting and removing residual silica contained in the treated water; A membrane separation aerobic tank installed at a rear end of the second gravity sedimentation tank and performing a solid-liquid separation and nitrification of the treated water by abandoning the treated water; A degassing tank installed at a rear end of the exhalation tank to reduce dissolved oxygen contained in the treated water introduced; A reaction tank that receives the treated water returned from the degassing tank and performs nitrification and denitrification contained in the treated water; And a scum storage tank installed at a rear end of the degassing tank to remove scum before discharge of the final treated water,
The first gravity settling tank, the second gravity settling tank, the membrane separation aerobic tank, the degassing tank, and the reaction tank are installed in parallel in a pair of left and right so as to be symmetrical, and for this purpose, a distribution tank is installed at the foremost stage where the wastewater flows, and the distribution tank is external. It receives raw water flowing from or treated water that has been pretreated, and distributes it to a pair of left and right first gravity sedimentation tanks.
In the reaction tank, a first reaction chamber for anaerobic and aerobic processes and a second reaction chamber for anaerobic processes are separately installed.
One of the reactors is set to the time for receiving the treated water in an anaerobic state from the degassing tank, and the other is to alternate the process cycle of the reactor by allowing the introduced treated water to perform an alternate reaction of anaerobic, aerobic and anaerobic. Silica-containing wastewater treatment device, characterized in that configured to be. According to claim 1,
Silica-containing wastewater treatment apparatus, characterized in that a connecting conduit is disposed between the first and second reaction chambers, and a heat supply means is additionally mounted on the connecting conduit. According to claim 2,
Silica-containing wastewater treatment apparatus characterized in that a vacuum pump is connected to the outside of the second reaction chamber together with a sealed structure for vacuum decompression.

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