KR102310305B1 - System for purifying groundwater - Google Patents

Abstract

The present invention relates to a groundwater treatment system, and more particularly, by supplying iron ions to groundwater using electricity to promote a reaction in which arsenic is converted into a solid precipitate to remove arsenic from groundwater, and then to the groundwater from which arsenic has been removed. It relates to a groundwater treatment system that can effectively remove arsenic, iron, and manganese contained in groundwater by removing iron and manganese existing in groundwater by supplying ozone and performing a radical oxidation reaction.

Description

Groundwater treatment system {System for purifying groundwater}

The present invention relates to a groundwater treatment system, and more particularly, by supplying iron ions to groundwater using electricity to promote a reaction in which arsenic is converted into a solid precipitate to remove arsenic from groundwater, and then to the groundwater from which arsenic has been removed. It relates to a groundwater treatment system that can effectively remove arsenic, iron, and manganese contained in groundwater by removing iron and manganese existing in groundwater by supplying ozone and performing a radical oxidation reaction.

Groundwater refers to the water that exists in the voids of the sediment below the surface of the earth or in the fracture surface of the bedrock. Compared to surface water, the development cost is cheap and easy, so it is widely used for agricultural, living and industrial water. However, since groundwater contains a large amount of iron and manganese dissolved in rocks and minerals, a purification process is required in order to use groundwater as drinking water.

As a method of purifying water, various methods such as filtering using a membrane, radical oxidation, electrolysis, chemical treatment, and heat treatment exist, as described in the following patent documents.

<Patent Literature>

Registered Patent Publication No. 10-1818651 (Registered on Jan. 09, 2018) "Membrane module housing that can be arranged in various ways"

However, some of the conventional water treatment methods are not suitable for preparing groundwater for drinking, and in particular, there is a problem in that groundwater containing arsenic, iron, manganese, organic matter, etc. cannot be effectively treated.

The present invention has been devised to solve the above problems,

An object of the present invention is to provide a groundwater treatment system capable of effectively removing arsenic, iron, and manganese contained in groundwater.

In addition, the present invention uses electricity to supply iron ions to groundwater to promote a reaction in which arsenic is converted into a solid precipitate to remove arsenic from groundwater, and then supply ozone to groundwater from which arsenic has been removed for radical oxidation reaction. An object of the present invention is to provide a groundwater treatment system capable of improving treatment efficiency by removing iron and manganese existing in groundwater.

In addition, the present invention uses a nanobubble device to supply ozone to groundwater, so that ozone nanobubbles increase the saturation solubility of ozone and increase the residence time, while generating hydroxyl radicals to promote oxidation and effectively iron, An object of the present invention is to provide a groundwater treatment system capable of removing manganese.

In addition, the present invention provides a groundwater treatment system capable of minimizing contamination by decomposition of organic matter in a radical oxidation reaction by converting arsenic into a solid precipitate and then removing organic foreign substances together with the arsenic precipitate in a separation tank. There is this.

In addition, in the present invention, groundwater is supplied from the oxidation tank to the membrane tank only by the pressure of water without power supply, and the groundwater treated in the membrane tank is supplied to the ozone treatment unit and moves to the oxidation tank, and iron and manganese are oxidized to form a precipitate. An object of the present invention is to provide a groundwater treatment system capable of reducing energy consumption while increasing treatment efficiency by repeating the process of being used and filtering through a membrane.

In addition, the present invention can minimize the inflow of groundwater from the oxidation tank into the connection pipe for supplying the membrane tank to the membrane tank in the process of the sediment descending from the oxidation tank, and groundwater that can move the groundwater discharged from the membrane tank toward the membrane It aims to provide a processing system.

The present invention is implemented by an embodiment having the following configuration in order to achieve the above object.

According to an embodiment of the present invention, the groundwater treatment system according to the present invention includes an electrical coagulation unit for supplying iron ions to groundwater using electrical energy to generate solid arsenic deposits to remove arsenic contained in groundwater; Arsenic, iron and manganese contained in groundwater, including an oxidation reaction treatment unit that forms solid iron and manganese precipitates by oxidizing iron and manganese by supplying ozone to groundwater from which arsenic has been removed through the electrocoagulation treatment unit It is characterized in that it can be removed.

According to another embodiment of the present invention, in the groundwater treatment system according to the present invention, the electric coagulation unit includes an electric coagulant for supplying iron ions to the groundwater using electric energy to generate solid arsenic deposits; and a separation tank for removing solid arsenic deposits and organic foreign substances from the groundwater that has passed through the group, wherein the anode of the electrocoagulator is made of iron.

According to another embodiment of the present invention, in the groundwater treatment system according to the present invention, the separation tank includes a first partition wall protruding from the inner lower surface and spaced apart from the inner upper surface by a predetermined distance, and protruding from the inner upper surface and spaced apart from the inner lower surface by a predetermined interval and a second bulkhead positioned to be spaced apart from the first bulkhead by a predetermined distance in the groundwater movement direction, wherein the first and second bulkheads are repeatedly formed in succession in the groundwater movement direction, and the groundwater passing through the electrical coagulator enters the inlet. is introduced into the separation tank, the water level rises, passes through the space between the first bulkhead and the upper surface, then falls to the lower side, passes through the space between the second bulkhead and the lower surface, and moves to the upper side. Since it is discharged through the outlet after repeating the process of passing through the space, arsenic deposits and organic foreign substances contained in the groundwater are characterized in that they are precipitated downward in the process of moving the separation tank.

According to another embodiment of the present invention, in the groundwater treatment system according to the present invention, the oxidation treatment unit includes an ozone treatment unit for supplying ozone to groundwater from which arsenic has been removed through the electrical coagulation treatment unit, and the groundwater passing through the ozone treatment unit. and an oxidation reaction tank in which iron and manganese contained in the ozone react with ozone to form a solid iron precipitate and manganese precipitate, wherein the ozone treatment unit supplies ozone to groundwater using a nanobubble device, so that ozone nanobubbles It is characterized in that it can promote the formation of hydroxyl radicals while increasing the saturation solubility of ozone and increasing the residence time.

According to another embodiment of the present invention, the groundwater treatment system according to the present invention further includes a filtration unit for filtering the groundwater that has passed through the oxidation treatment unit, and the filter unit communicates with the oxidation reaction vessel and is discharged from the oxidation vessel. a membrane tank for accommodating the groundwater, and a membrane positioned inside the membrane tank to filter groundwater in the membrane tank, wherein the oxidation reaction tank and the separation membrane tank are connected to each other by a connecting pipe, and the groundwater of the oxidation tank is subjected to the pressure of water It is characterized in that it moves to the separation membrane tank through the connecting pipe.

According to another embodiment of the present invention, in the groundwater treatment system according to the present invention, the connection pipe has a connection part located at one end in the oxidation reaction tank and the other end in the separation membrane tank, and one end of the connection part is bent downward to form the groundwater It is characterized in that it is possible to minimize the inflow of the sediment into the connection pipe in the process of descending from the oxidation tank by including a downward bending part to be introduced and an upward bending part bent upward at the other end of the connection part to discharge groundwater. do.

According to another embodiment of the present invention, in the groundwater treatment system according to the present invention, the membrane is connected to a circulation pipe, and one end of the circulation pipe communicates with the inner space of the membrane and the other end is connected to the ozone treatment unit, The groundwater filtered through the membrane is supplied to the ozone treatment unit again, so that the process of oxidizing iron and manganese to form a precipitate and the process of filtering through the membrane are repeated.

According to another embodiment of the present invention, the groundwater treatment system according to the present invention is characterized in that it further includes a discharge treatment unit for discharging sediment through a discharge line connected to the lower surface of the oxidation reactor.

The present invention can obtain the following effects by the configuration, combination, and use relationship described below with the present embodiment.

The present invention has the effect of effectively removing arsenic, iron, and manganese contained in groundwater.

In addition, the present invention uses electricity to supply iron ions to groundwater to promote a reaction in which arsenic is converted into a solid precipitate to remove arsenic from groundwater, and then supply ozone to groundwater from which arsenic has been removed for radical oxidation reaction. It has the effect of improving the treatment efficiency by removing iron and manganese existing in the groundwater.

In addition, the present invention uses a nanobubble device to supply ozone to groundwater, so that ozone nanobubbles increase the saturation solubility of ozone and increase the residence time, while generating hydroxyl radicals to promote oxidation and effectively iron, It has the effect of removing manganese.

In addition, the present invention has an effect of minimizing contamination by decomposition of organic matter in a radical oxidation reaction by converting arsenic into a solid precipitate and then removing organic foreign substances together with the arsenic precipitate in a separation tank.

In addition, in the present invention, groundwater is supplied from the oxidation tank to the membrane tank only by the pressure of water without power supply, and the groundwater treated in the membrane tank is supplied to the ozone treatment unit and moves to the oxidation tank, and iron and manganese are oxidized to form a precipitate. By repeating the process of filtration and the process of filtering through a membrane, there is an effect of reducing energy consumption while increasing treatment efficiency.

In addition, the present invention can minimize the inflow of groundwater from the oxidation reaction tank into the connection pipe for supplying the separation membrane tank to the membrane tank in the process of the sediment descending from the oxidation tank, and the effect of moving the groundwater discharged from the membrane tank toward the membrane there is

1 is a block diagram of a groundwater treatment system according to an embodiment of the present invention;
2 is a block diagram of a groundwater treatment system according to an embodiment of the present invention.
Figure 3 is a reference diagram for explaining the separation tank of Figure 2;
4 is a reference diagram for explaining the connection relationship between the oxidation reaction tank and the filtration tank of FIG.

Hereinafter, a groundwater treatment system according to the present invention will be described with reference to the accompanying drawings. Unless otherwise defined, all terms in this specification have the same general meaning as understood by those skilled in the art to which the present invention belongs, and in case of conflict with the meaning of the terms used in this specification, the According to the definition used in the specification. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the gist of the present invention will be omitted. Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

1 is a block diagram of a groundwater treatment system according to an embodiment of the present invention, FIG. 2 is a block diagram of the groundwater treatment system according to an embodiment of the present invention, and FIG. 3 is a diagram for explaining the separation tank of FIG. It is a reference diagram, and FIG. 4 is a reference diagram for explaining the connection relationship between the oxidation reaction tank and the filtration tank of FIG. 2 .

1 to 4 of the groundwater treatment system according to an embodiment of the present invention, the groundwater treatment system supplies iron ions to groundwater using electrical energy to generate solid arsenic precipitates and include them in groundwater. Formation of solid iron and manganese deposits by oxidizing iron and manganese by supplying ozone to groundwater from which arsenic has been removed through an electrocoagulation treatment unit 1 that removes arsenic and the electrocoagulation treatment unit 1 and an oxidation reaction processing unit 2, and a filtering unit 3 filtering groundwater that has passed through the oxidation reaction processing unit 2, and the like.

The electrical coagulation processing unit 1 is configured to remove arsenic contained in the groundwater by supplying iron ions to the groundwater using electrical energy to generate solid arsenic deposits. ), etc.

The electrocoagulant 11 is configured to supply iron ions to groundwater using electrical energy to generate solid arsenic precipitates. A conventional electrocoagulator in which metal ions are eluted from the anode may be used, but the anode is characterized in that it is made of iron. In some areas (e.g., pyeru, etc.) there is the ground water contains arsenic arsenic In order to use the underground water by toxic substances in water, and the like must be removed, ground arsenic is HAs (Ⅴ) O ₄ ^2- in the form of +5 When iron ions are supplied in excess, the reaction as shown in Scheme 1 below is promoted to form a solid arsenic precipitate (Fe(II)Fe(III)As(III)O ₄ (s)). That is, the groundwater supplied from the water collecting tank 100 for temporarily storing the groundwater passes through the electric coagulator 11, and arsenic contained in the groundwater is changed to a solid sediment. As with the movement of groundwater from the water collecting tank 100 to the electric coagulator 11, the movement of groundwater is made by the operation of a pump and a valve, which is not related to the gist of the invention, so it is not shown, and a detailed description thereof is omitted. decide to do

[Scheme 1]

HAs(V)O ₄ ^2- + 2Fe ²⁺ + 4H ^{+ →} H ₃ As(III)O ₃ + 2Fe ³⁺ + H ₂ O

H ₃ As(V)O ₃ + 2Fe ³⁺ + Fe ²⁺ + 4H ₂ O ^→ Fe(II)Fe(III)As(III)O ₄ (s) + Fe(OH) ₃ + 8H ⁺

The separation tank 12 is configured to remove foreign substances such as solid arsenic deposits and organic matter from the groundwater that has passed through the electric coagulator 11, and a first partition wall ( 121) and a second partition wall 122 protruding from the inner upper surface, spaced apart from the inner lower surface by a predetermined interval, and spaced apart from the first partition wall 121 by a predetermined interval in the groundwater movement direction, wherein the first partition wall 121 ) and the second partition wall 122 are continuously and repeatedly formed in the direction of the movement of groundwater. The groundwater that has passed through the electric coagulator 11 is introduced into the separation tank 12 through the inlet 123, the water level rises, passes through the space S1 between the first bulkhead 121 and the upper surface, and then moves downward. After passing through the space S2 between the second partition wall 122 and the lower surface, it moves upward again and repeats the process of passing through the space between the first partition wall 121 and the upper surface, and then discharges through the outlet 124 Therefore, foreign substances such as arsenic deposits and organic matter contained in the groundwater are precipitated downward in the process of moving the separation tank 12 . Since the lower surface of the separation tank 12 communicates with a discharge line 41 to be described below, foreign substances such as arsenic deposits and organic matter deposited on the bottom of the separation tank 12 through the discharge line 41 are removed from the separation tank. (12) can be removed.

The oxidation treatment unit (2) supplies ozone to groundwater from which arsenic has been removed through the electrocoagulation treatment unit (1) to oxidize iron and manganese to form solid iron deposits and solid manganese deposits. (21), an oxidation reaction tank (22) and the like.

The ozone treatment unit 21 is configured to supply ozone to groundwater from which arsenic has been removed through the electric coagulation treatment unit 1, and the ozone treatment unit 21 may be a conventional ozone treatment device that supplies ozone to water. , preferably by supplying ozone to the groundwater using a nanobubble device to increase the saturation solubility of ozone by ozone nanobubbles and to promote the generation of hydroxyl radicals while increasing the residence time.

The oxidation reaction tank 22 is configured such that iron and manganese contained in the groundwater passing through the ozone treatment unit 21 react with ozone to form a solid iron precipitate and a solid manganese precipitate, and the ozone treatment unit 21 The groundwater mixed with ozone is introduced through the , and iron and manganese contained in the groundwater react with ozone as shown in Reaction Equations 2 and 3 below to form solid iron deposits (Fe(OH) ₃ (s)), solid manganese A precipitate (MnO ₂ (s)) is formed. In addition, as shown in Scheme 4 below, hydroxyl radicals are generated in groundwater to further accelerate the oxidation reaction of iron and manganese. Since the lower surface of the oxidation tank 22 communicates with a discharge line 41 to be described later, iron and manganese deposits stacked on the bottom of the oxidation tank 22 through the discharge line 41 are removed from the oxidation tank 22 ) can be removed.

[Scheme 2]

2Fe ²⁺ + O ₃ + H ₂ O → 2Fe ³⁺ + O ₂ + 2OH ^-,

Fe ³⁺ + 3H ₂ O → Fe(OH) ₃ (s) + 3H ⁺

[Scheme 3]

Mn ²⁺ + O ₃ + H ₂ O → MnO ₂ (s) + O ₂ + 2H+

[Scheme 4]

O ₃ + H ₂ O → HO ₃ ⁺ + OH ^- → 2HO ₂ ^,

O ₃ + HO ₂ ^, → HO ^, + 2O ₂

HO ₂ ^, + HO ₂ ^, → H ₂ O ₂ + O ₂

The filtering unit 3 filters the groundwater that has passed through the oxidation reaction treatment unit 2 and includes a separation membrane tank 31 and a membrane 32 .

The membrane tank 31 communicates with the oxidation tank 22 to receive the groundwater discharged from the oxidation tank 22 , and the membrane 32 is positioned inside the membrane tank 31 . The oxidation tank 22 and the membrane tank 31 are connected to each other by a connecting pipe 311, and the groundwater in the oxidation tank 22 is moved to the membrane tank 31 through the connecting pipe 311 by the pressure of water. will do The connecting pipe 311 has a connecting part 311a having one end located in the oxidation tank 22 and the other end in the separation membrane tank 31, and one end of the connecting part 311a is bent downward to introduce groundwater. Including a bent part 311b and an upward bent part 311c bent upward from the other end of the connection part 311a to discharge groundwater, etc., the connection pipe in the process of the sediment downward in the oxidation reaction tank 22 Inflow into the 311 can be minimized, and the groundwater discharged from the separation membrane tank 31 moves toward the membrane 32 . Since the lower surface of the separation membrane tank 31 communicates with the discharge line 41 to be described below, the sediment deposited on the bottom of the separation membrane tank 31 through the discharge line 41 is removed from the separation membrane tank 31. be able to

The membrane 32 is positioned inside the membrane tank 31 above the upwardly bent part 311c to filter the groundwater in the membrane tank 31, and has an empty space inside, and the outside of the membrane As groundwater moves into the inside, it is filtered. The membrane 32 is connected to the circulation pipe 321, and one end of the circulation pipe 321 communicates with the inner space of the membrane 32 and the other end is connected to the ozone treatment unit 21, so that the membrane ( The groundwater filtered through 32) is supplied to the ozone treatment unit 21 again, so that the process of oxidizing iron and manganese to form a precipitate and the process of filtering through the membrane are repeated, so that the treatment efficiency can be increased, and the oxidation reaction tank Since there is no power supply to the separation membrane tank, the energy consumption can be reduced by supplying groundwater only with the pressure of water. After the process in which the iron and manganese are oxidized to form a precipitate and the process of filtering through the membrane are repeated a certain number of times, the groundwater is discharged to and used in the storage tank 200 for storing the treated water.

The discharge treatment unit 4 is configured to remove the sediment generated in the process of treating groundwater, and discharges the sediment through the discharge line 41 connected to the lower surface of the separation tank, the oxidation reaction tank, the separation membrane tank, and the like. The groundwater treatment system does not perform the radical oxidation reaction first, but supplies iron ions to the groundwater through an electrocoagulation treatment process to promote the conversion of arsenic into a solid precipitate to remove arsenic from the groundwater, and then By supplying ozone to the removed groundwater to undergo a radical oxidation reaction, iron and manganese present in the groundwater are removed, and arsenic, iron, and manganese can be effectively removed from the groundwater. In addition, when ozone is supplied to organic matter, organic matter is decomposed to generate contaminants that are difficult to remove. By removing organic foreign substances together with arsenic deposits before radical oxidation reaction, new pollution can be minimized and economic feasibility can be promoted.

In the above, the applicant has described preferred embodiments of the present invention, but these embodiments are only one embodiment that implements the technical idea of the present invention, and any changes or modifications as long as the technical idea of the present invention is implemented. should be construed as within the scope.

1: Electrocoagulation treatment section 2: Oxidation treatment section 3: Filtration section
4: Discharge treatment unit 11: Electrocoagulant 12: Separation tank
21: ozone treatment unit 22: oxidation reaction tank 31: membrane tank
32: membrane 41: discharge line 121: first bulkhead
122: second bulkhead 123: inlet 124: outlet
311: connector 321: circulation pipe 311a: connection part
311b: downward bent part 311c: upward bent part 100: water tank
200: storage tank

Claims (8)

In the groundwater treatment system for treating groundwater containing arsenic, organic matter, iron and manganese,
The groundwater treatment system includes an electrocoagulant for supplying iron ions to groundwater using electrical energy to generate solid arsenic precipitates, and a separation tank for removing solid arsenic precipitates and organic matter from the groundwater that has passed through the electrocoagulant; Ozone is supplied to groundwater from which arsenic and organic matter has been removed through a separation tank to oxidize iron and manganese to form a solid iron precipitate and manganese precipitate; It includes a filtration unit, and a discharge line connected to the lower surface of the separation tank and the oxidation reaction tank,
The separation tank includes a first partition wall protruding from the inner lower surface and spaced apart from the inner upper surface by a predetermined interval, a second partition wall protruding from the inner upper surface and spaced apart from the inner lower surface by a predetermined interval, and spaced apart from the first partition wall by a predetermined interval in the groundwater movement direction. The first bulkhead and the second bulkhead are repeatedly formed in succession in the groundwater movement direction, and the groundwater that has passed through the electric coagulator is introduced into the separation tank through the inlet, and the water level rises to pass through the space between the first bulkhead and the upper surface. Then, it falls to the lower side and passes through the space between the second bulkhead and the lower surface, then moves to the upper side and repeats the process of passing through the space between the other first bulkhead and the upper surface. Arsenic deposits and organic matter precipitate downward in the process of moving the separation tank and are discharged to the outside through the discharge line,
The oxidation reaction treatment unit includes an ozone treatment unit that supplies ozone to groundwater from which arsenic and organic matter have been removed through the separation tank, and iron and manganese contained in the groundwater that has passed through the ozone treatment unit reacts with ozone to form solid iron deposits and Including an oxidation reaction tank to form a manganese precipitate,
The filtration unit includes a membrane tank communicating with the oxidation tank to receive the groundwater discharged from the oxidation tank, and a membrane positioned inside the membrane tank to filter the groundwater in the membrane tank, wherein the oxidation tank and the membrane tank are connected connected to each other, the groundwater in the oxidation reaction tank moves to the membrane tank through the connection pipe by the pressure of water,
The connecting pipe has one end in the oxidation reaction tank and the other end in the separation membrane tank; The groundwater treatment system, characterized in that it can minimize the inflow of the sediment into the connection pipe in the process of descending from the oxidation reaction tank, including an upward bent part to be discharged. delete delete According to claim 1,
The ozone treatment unit supplies ozone to the groundwater by using a nanobubble device, thereby increasing the saturation solubility of ozone by ozone nanobubbles, increasing the residence time, and promoting the generation of hydroxyl radicals. system. delete delete According to claim 1,
The membrane is connected to a circulation pipe, and one end of the circulation pipe communicates with the inner space of the membrane and the other end is connected to an ozone treatment unit, and groundwater filtered through the membrane is supplied to the ozone treatment unit again, so that iron and manganese A groundwater treatment system, characterized in that the process of oxidized sediment formation and filtration through a membrane are repeated. delete

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