KR102273723B1 - Ammonia Treatment System for Wastewater Using Electrolysis - Google Patents

Abstract

The present invention relates to an ammonia treatment device for wastewater using electrolysis, which removes ammonia from wastewater from food waste or livestock waste. More specifically, the ammonia treatment device: mixes wastewater with air in an ejector (21); sprays the same from a degassing tower (200) so that ammonia (NH_3) is separated and discharged from the wastewater by the contact reaction with air; and has the separated and discharged ammonia react with the washing water mixed with hydrochloric acid (HCl) in an absorption tower (300) to generate ammonium chloride (NH_4Cl) and perform the electrolysis process in an electrolysis means (400). The present invention includes + and - electrode plates (46) and (46') in parallel in a compartment (44) partitioned along the longitudinal direction inside a body so that the aqueous ammonium chloride solution passes through the compartment inside the body zigzag to perform the electrolysis process and destroy ammonia. Accordingly, the ammonia is discharged in exhaust gas such as nitrogen and hydrogen. Thus, the generation of scale on the electrode plate is reduced and the ammonia treatment efficiency of wastewater is maximized.

Description

Ammonia Treatment System for Wastewater Using Electrolysis

The present invention relates to a wastewater ammonia treatment apparatus for removing ammonia from wastewater from food waste or livestock waste, and more particularly, by separating ammonia from wastewater in a degassing tower and reacting it with hydrochloric acid in an absorption tower to form ammonium chloride (NH ₄ Cl) is generated and then ammonia is destroyed through an electrolysis process and discharged as exhaust gases such as nitrogen and hydrogen. It relates to an ammonia treatment device for wastewater using electrolysis.

In general, wastewater such as food or livestock waste contains a large amount of ammonia and is discharged.

As such, ammonia in wastewater is itself a pollutant, which not only destroys the aquatic ecosystem and loses the value of water resources, but also causes eutrophication, which further deteriorates water quality.

Therefore, various methods for removing ammonia from the wastewater have been proposed, and mainly biological methods and physicochemical methods have been widely used.

In particular, when wastewater such as food or livestock waste contains a high concentration of ammonia, a method of linking ion exchange, membrane separation, and air stripping with a biological method and a physicochemical method is known to be more efficient.

For example, in Patent No. 10-0886533, etc., after pH adjustment and temperature adjustment of high concentration ammonia-containing wastewater of food or livestock waste, ammonia is separated into gas by contact between liquid wastewater and air in a degassing tower, and this separated Ammonia was allowed to fertilize in an absorption tower.

In addition, there has been disclosed a technique using an electrolysis method to remove ammonia from the wastewater, which causes an electrolytic reaction by putting the wastewater into an electrolysis tank, so that ammonia in the wastewater is released as nitrogen and hydrogen.

However, the above conventional methods have a limitation in not maximizing the ammonia treatment efficiency of the wastewater.

In other words, when biological method, physicochemical method, and electrolysis method are applied respectively, and especially when electrolysis of food waste, livestock manure, waste leachate, etc. with high ammonia concentration, ammonia removal efficiency is high at first, but Due to the formation of scale, the efficiency of ammonia treatment fell sharply, causing many problems in actual operation.

In addition, in the structure of the conventional electrolysis device, assembling, installing, disassembling, and cleaning the electrode plate are inconvenient in the structure of the conventional electrolysis device, so there are several problems in applying it to an ammonia treatment device for wastewater.

Publication No. 2002-0060792 (July 19, 2002) Registered Patent No. 10-1644275 (July 25, 2016)

The present invention was invented to solve the problems of the prior art, and after separating ammonia from wastewater in a degassing tower and reacting it with hydrochloric acid in an absorption tower to produce ammonium chloride (NH ₄ Cl), it is electrolyzed. Since ammonia is destroyed and discharged as exhaust gas such as nitrogen and hydrogen, the purpose is to maximize the ammonia treatment efficiency of the wastewater while reducing the scale generation of the electrode plate.

The present invention further provides a post-treatment means for removing the odor of exhaust gas discharged after the electrolysis process together with a pre-treatment means for agglomeration and separation of foreign substances before separation of ammonia in the wastewater, improving the treatment efficiency of the wastewater, and effectively reducing the emission of odors The purpose is to prevent it.

According to the present invention, wastewater from various food wastes or livestock waste is mixed with air supplied by a blower from an ejector and then supplied from the upper part of the tower to the lower part, and the air supplied from the blower is supplied from the lower part of the tower to the upper part, but the wastewater and the air is dissolved is supplied from the lower the in contact reaction in the media ammonia (NH ₃₎ separate discharge degassing tower and, for the separate discharge of ammonia (NH ₃₎ in the stripping tower the tower to the upper part, and hydrochloric acid (HCl) is added number and, but the air supplied from the tower top to bottom, the ammonium chloride produced in the ammonia and the absorption tower and the absorption tower of hydrochloric acid is in contact reaction in the media generation of ammonium chloride (NH ₄ Cl) in aqueous (NH ₄ Cl) The electrolysis process is performed while the aqueous solution is circulated to the main body by a pump, but the main body has an inlet and an outlet on both sides, and opposite sides are opened along the longitudinal direction inside to form a zigzag transfer path. A compartment is partitioned by a plurality of partition walls, and + and - electrode plates are installed in parallel in each compartment, and an air injection unit that sprays air between the electrode plates is connected and installed at the bottom to destroy ammonia by electrolysis of ammonium chloride aqueous solution. It is characterized in that it is composed of an electrolysis means for discharging exhaust gases such as nitrogen and hydrogen.

According to the present invention, the + and - electrode plates are formed in a rectangular bar type, inserted into installation grooves formed at regular intervals on the insulating plate, installed vertically spaced apart from each other, and penetrated at the same height as the top and bottom of the electrode plate. It is characterized in that it is configured to be assembled to support each other by inserting the support into the formed through-hole, but to be integrally inserted and installed in each compartment of the body or to be separated.

According to the present invention, a storage tank for storing an aqueous solution of _{ammonium chloride (NH 4} Cl) is provided between the absorption tower and the electrolysis means _{to supply an aqueous solution of ammonium chloride (NH 4} Cl) by adjusting the pH to 4-5. There is a characteristic.

According to the present invention, in the upstream of the degassing column, a chemical is added to the wastewater in the reaction water tank, stirred by a stirrer to agglomerate foreign substances, and separated by floating or precipitation by a swash plate. A pre-treatment means for adding and storing sodium hydroxide for the electrolysis means, and a post-treatment means for discharging the exhaust gas from the lower part of the tower to the upper part and removing the residual odor of the exhaust gas while spraying the washing water from the upper part to the lower part of the electrolysis means It is characterized in that it is configured to provide more.

_{The present invention separates and discharges ammonia (NH 3} ) from wastewater by a contact reaction with air while mixing wastewater with air in an ejector and spraying it in a degassing tower, and discharging the separated and discharged ammonia with hydrochloric acid (HCl) in an absorption tower _{The electrolysis process is performed in the electrolysis means by generating ammonium chloride (NH 4} Cl) in an aqueous solution state while reacting with the mixed washing water, which is a +,- electrode plate in a compartment partitioned along the longitudinal direction inside the body. is installed in parallel so that the ammonium chloride aqueous solution zigzags through the compartment inside the body to perform the electrolysis process while destroying ammonia and discharging it as exhaust gas such as nitrogen and hydrogen, reducing the scale generation of the electrode plate and the ammonia treatment efficiency of wastewater will be maximized.

In addition, a post-treatment means for removing the odor of the exhaust gas discharged after the electrolysis process is further provided together with a pre-treatment means for coagulating and separating foreign substances from the wastewater in front of the degassing tower, thereby further increasing the efficiency of wastewater treatment and releasing the odor It has the effect of preventing it more effectively.

1 is an overall configuration diagram showing an apparatus of the present invention.
2 to 4 are enlarged views of the main part of FIG. 1 .
5 is a sectional view showing the main part of the electrolysis means of the present invention.
Fig. 6 is a side cross-sectional view of Fig. 5;
Fig. 7 is a plan cross-sectional view of Fig. 5;
8 is a perspective view of a main part showing the electrode plate assembly structure of FIG. 5;

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIGS. 1 to 8, the ammonia treatment apparatus for wastewater using electrolysis of the present invention includes a pretreatment means 100) for separating and removing suspended solids and sediments (foreign substances) from wastewater, and the wastewater passing through the pretreatment means A degassing tower 200 for separating ammonia (NH ₃ ) from, and an absorption tower 300 for reacting the ammonia separated in the degassing column with hydrochloric acid (HCl) to produce an aqueous solution of _{ammonium chloride (NH 4 Cl); The electrolysis means 400 for discharging the ammonium chloride (NH 4} Cl) aqueous solution generated in the absorption tower as exhaust gas such as nitrogen and hydrogen by the ammonia destruction process by electrolysis, and the exhaust gas discharged from the electrolysis means It is composed of a post-processing means 500 that removes the odor of the odor and then discharges it to the outside.

The pretreatment means 100 includes a reaction tank 11 in which a chemical is added to wastewater and agitated by a stirrer 12 to agglomerate foreign substances and separated by a swash plate 13 in a floating or settling state, and the reaction tank It consists of a treatment water tank 15 that stores wastewater from which foreign substances are separated from the deaeration and stores sodium hydroxide for pH adjustment appropriate for degassing.

At this time, the reaction tank 11 transports and discharges foreign substances (sludge) to the sludge storage tank 16 by the discharge pump, and the wastewater in the treatment tank 15 is transferred to the degassing tower 200 by the pump 17 configured to supply.

The degassing tower 200 mixes wastewater with the air supplied by the blower 22 from the ejector 21 and supplies it from the top of the tower to the bottom, and the air supplied from the blower 22 from the bottom of the tower to the top However, the wastewater and air are configured to separate and discharge _{ammonia (NH 3} ) while contacting and reacting in the media 23 .

At this time, ammonia separated from the wastewater is discharged to the upper portion of the degassing tower, and the ammonia-separated wastewater is stored in the lower portion of the degassing tower and then discharged to the wastewater collection tank 26 by the discharge pump 25 .

The absorption tower 300 supplies ammonia separated and discharged from the degassing tower from the lower part of the tower to the upper part, and the dissolved water and air to which hydrochloric acid (HCl) is added are supplied from the upper part of the tower to the lower part, but the ammonia and hydrochloric acid are the media ( 33) is configured to produce ammonium chloride (NH ₄ Cl) in an aqueous solution state while catalytically reacting.

At this time, the hydrochloric acid (HCl) is stored in the hydrochloric acid storage tank 35 and added to the aqueous solution at the bottom of the absorption tower by the pump 36, and the aqueous solution of ammonium chloride in the absorption tower is supplied by the pump 41 to be described later. It is configured to supply dissolved water supplied from the upper part of the tower to the lower part by the circulation pump 37 while being supplied to the electrolysis means 400 .

The electrolysis means 400 supplies the ammonium chloride (NH ₄ Cl) aqueous solution generated in the absorption tower 300 into the body 42 by transferring the pump 41 and recirculates it to the absorption tower after the electrolysis process. to compose

Here, the main body 42 forms an inlet and an outlet on both sides, and divides the compartment 44 by a plurality of partition walls 43 so as to form a zigzag transport path while opening opposite sides along the longitudinal direction therein. + and - electrode plates 46 and 46' are formed in parallel in each of the compartments 44, and an air injection part 45 for spraying air between the electrode plates is formed in the lower portion of each compartment to form ammonium chloride (NH ₄ Cl) It is configured to be discharged as exhaust gas such as nitrogen and hydrogen while destroying ammonia by electrolysis of aqueous solution.

At this time, the exhaust gas is discharged in proportion to the amount of air injected from the air injection unit 45 .

In addition, the +, - electrode plates 46 and 46' of the electrolysis means are vertically installed to be spaced apart from each other by inserting them into the installation grooves 47a formed at regular intervals on the insulating plate 47, and the electrode plates are The support 48 is inserted into the through-holes 46a formed through the upper and lower same heights to be integrally assembled while being integrally inserted into each compartment 44 of the main body and configured to be installed and detached.

By inserting spacer rings (48a) positioned between the electrode plates in the support 48, the electrode plate is configured to be fixedly installed so as to maintain a predetermined interval without flowing left and right.

And when the ammonium chloride (NH ₄ Cl) aqueous solution is generated in the absorption tower 300 , it is preferably operated at a pH of 1 to 2 and the electrolysis means 400 is operated at a pH of 4 to 5 .

To this end, a storage tank 49 for storing an aqueous solution of _{ammonium chloride (NH 4} Cl) is provided between the absorption tower 300 and the electrolysis means 400 to adjust the pH of the aqueous solution of _{ammonium chloride (NH 4 Cl) in the storage tank.} to configure it to do so.

The post-treatment means 500 induces the exhaust gas discharged from the main body 42 of the electrolysis means to be discharged from the lower part of the tower 51 to the upper part, and while spraying the washing water from the upper part of the tower to the lower part, the odor of the exhaust gas (residual Ammonia, etc.) is dissolved and removed.

As an unexplained reference numeral, 47b denotes a support plate vertically installed before and after the insulating plate 47 , 48b denotes a fastening member, and 55 denotes a circulation pump.

Next, we will look at the operation and operation of the present invention configured as described above.

First, wastewater from food waste or livestock waste is supplied to the reaction tank 11 of the pretreatment means 100, and then a chemical is added thereto and stirred by the stirrer 12 to agglomerate foreign substances, so that it floats or settles.

In this state, after separating foreign substances suspended or precipitated by the swash plate 13, the wastewater is supplied to the treatment tank 15 and stored by adding sodium hydroxide to adjust the pH suitable for degassing, and the foreign substances (sludge) are discharged by the discharge pump It is to be discharged to the sludge storage tank 16 by the.

The wastewater stored in the treatment tank 15 is transferred and supplied to the degassing tower 200 by the pump 17, mixed with the air supplied by the blower 22 in the ejector 21, and then supplied from the upper part of the tower to the lower part. will do

Along with this, the air supplied from the blower 22 is supplied from the lower part of the tower to the upper part.

As described above, while the wastewater supplied from the upper part of the tower to the lower part and the air supplied from the lower part to the upper part react in contact with the media 23 , ammonia (NH ₃ ) is separated from the wastewater and discharged to the upper part.

And the ammonia-separated wastewater is discharged to the wastewater collection tank 26 by the discharge pump 25 from the lower part of the degassing tower 200 .

_{Ammonia (NH 3} ) discharged to the upper portion of the degassing tower 200 is supplied from the lower portion of the tower to the upper portion of the absorption tower 300 .

In addition, hydrochloric acid (HCl) of the hydrochloric acid storage tank 35 is supplied to the lower part of the absorption tower 300 by the pump 36, and the dissolved water to which the hydrochloric acid (HCl) is added is circulated by the circulation pump 37 It will be supplied from the top of the tower to the bottom.

As such, the dissolved water and air supplied with hydrochloric acid (HCl) supplied from the upper part of the tower to the lower part, and ammonia (NH ₃ ) supplied from the lower part of the tower to the upper part, react with ammonium chloride (NH ₄ Cl) in the media 33 . ) is generated in an aqueous solution state and stored in the lower portion of the absorption tower 300 .

The ammonium chloride (NH ₄ Cl) aqueous solution thus generated is transferred to the pump 41 and supplied to the main body 42 of the electrolysis means.

At this time, since the absorption tower 300 operates _{at pH 1 to 2 when an aqueous solution of ammonium chloride (NH 4} Cl) is generated, it is adjusted to pH 4 to 5 and supplied to the electrolysis means 400 while performing the electrolysis process. it is safe to do

To this end, it is stored in the storage tank 49 between the absorption tower 300 and the electrolysis means 400 to adjust the pH and then supply it to the main body 42 of the electrolysis means.

_{As such, the ammonium chloride (NH 4} Cl) aqueous solution supplied to one side of the main body 42 of the electrolysis means is divided by a plurality of partition walls 43 having opposite sides opened along the longitudinal direction inside the body ( 44) in a zigzag form, the electrolysis process by the + and - electrode plates 46 and 46' installed in each of the compartments 44 is performed in multiple stages.

That is, in each of the compartments 44, + and - electrode plates 46 and 46' are installed in parallel, so that an _{aqueous solution of ammonium chloride (NH 4} Cl) passes between the electrode plates, and ammonia (NH ₃ ) is destroyed to generate exhaust gas that is decomposed into nitrogen (N) and hydrogen (H).

Various reactions occur in the electrolysis process of the electrolysis means as described above. Some examples are as follows.

(One). NH ₄ Cl + Cl ₂ → NH ₂ Cl + 2HCl

(2). 3NH ₂ Cl → N _{2 +} NH ₄ Cl + 2HCl

(3). 4NH ₂ Cl → N _{2 + 2} NH ₄ Cl + Cl ₂

(4). NH ₂ Cl + Cl ₂ → NHCl ₂ + HCl

(5). NHCl ₂ + Cl ₂ → NCl ₃ + HCl

(6). 8NHCl ₂ → N _{2 +} 2NH ₄ Cl + 7Cl ₂

(7). 2NH ₄ Cl + 3Cl ₂ → N _{2 +} 8HCl

As such, the exhaust gas such as nitrogen and hydrogen generated by the electrolysis process is discharged to the upper portion of the body 42, and the amount of air injected by the air injection unit 45 from the lower portion of the body 42 is the exhaust gas. It will be discharged to the upper part in proportion to .

On the other hand, the +, - electrode plates 46 and 46' of the electrolysis means are inserted into the installation grooves 47a formed at regular intervals on the insulating plate 47, and the electrode plates are supported through the through-holes 46a. (48) is inserted, but the spacer ring (48a) inserted at the position between the electrode plates is also inserted together so that each electrode plate forms a certain distance and is integrally combined and assembled inside the body 42, such as installation, disassembly, cleaning, etc. This will be done simply.

In this way, the exhaust gas discharged from the electrolysis means 400 is induced to be discharged from the lower part of the tower 51 of the post-treatment means 500 to the upper part, and while the washing water is sprayed from the upper part of the tower to the lower part, the odor of the exhaust gas (residual Ammonia, etc.) is dissolved and removed and then released to the outside.

Therefore, the present invention _{separates ammonia (NH 3} ) from wastewater and reacts the separated and discharged ammonia with washing water mixed with hydrochloric acid (HCl) _{to generate ammonium chloride (NH 4} Cl) in an aqueous solution state to generate electricity The electrolysis process is performed in the decomposition means, but + and - electrode plates are installed in parallel in the compartments partitioned along the longitudinal direction inside the body so that the aqueous ammonium chloride solution passes through the compartment inside the body zigzag while performing the electrolysis process. By destroying it and discharging it as exhaust gas such as nitrogen, hydrogen, etc., it is possible to effectively treat ammonia in the wastewater while reducing the generation of scale on the electrode plate.

In addition, the present invention will be able to solve this simply while using an electrolysis means for the treatment of some ammonium sulfate or ammonium phosphate that may be generated other than _{ammonium chloride (NH 4 Cl) in the absorption tower.}

11: reaction bath 12: stirrer
13: swash plate 15: treatment tank
21: ejector 22: blower
23,33: media 41: pump
42: body 43: bulkhead
44: compartment 45: air inlet
46,46': electrode plate 46a: through hole
47: insulation plate 47a: mounting groove
48: support 49: reservoir
100: pretreatment means
200: degassing tower
300: absorption tower
400: electrolysis means
500: post-processing means

Claims (4)

In the ammonia treatment apparatus of wastewater to remove ammonia from various wastewater,
The wastewater is mixed with air supplied by the blower 22 from the ejector 21 and supplied from the top of the tower to the bottom, and the air supplied from the blower 22 is supplied from the bottom of the tower to the top, but the wastewater and air A degassing tower 200 for separating and discharging _{ammonia (NH 3} ) while catalytically reacting in the gas media 23;
Ammonia separated and discharged from the degassing tower is supplied from the lower part of the tower to the upper part, and dissolved water and air to which hydrochloric acid is added are supplied from the upper part of the tower to the lower part, but the ammonia and hydrochloric acid (HCl) are reacted in the media (33). Absorption tower 300 for generating ammonium chloride (NH ₄ Cl) in an aqueous solution state and,
_{The electrolysis process is performed while circulating and supplying the ammonium chloride (NH 4} Cl) aqueous solution generated in the absorption tower to the body 42 by the pump 41, wherein the body 42 has an inlet and an outlet on both sides, The compartments 44 are partitioned by a plurality of partition walls 43 so as to form a zigzag-shaped transport path with opposite sides opened along the longitudinal direction therein, and each compartment 44 has + and - electrode plates ( 46) (46') are installed in parallel, and an air injection part 45 for spraying air between the electrode plates is connected to the lower part, so that the electrolysis means 400 is discharged as exhaust gas while destroying ammonia by electrolysis of ammonium chloride aqueous solution. ) Ammonia treatment device for wastewater, characterized in that it consists of.
According to claim 1,
The + and - electrode plates 46 and 46' of the electrolysis means are formed in a rectangular bar type and inserted into the installation grooves 47a formed at regular intervals on the insulating plate 47 to be vertically spaced apart from each other. Installed and assembled to support each other by inserting the supports 48 into the through-holes 46a formed through the electrode plate at the same height as the top and bottom, but configured to be integrally inserted and installed in each compartment 44 of the body or to be separated Ammonia treatment device for wastewater, characterized in that.
According to claim 1,
A storage tank 49 for storing an aqueous solution of _{ammonium chloride (NH 4} Cl) is provided between the absorption tower 300 and the electrolysis means 400, and the _{aqueous solution of ammonium chloride (NH 4} Cl) is adjusted to pH 4-5 and supplied. Ammonia treatment apparatus for wastewater, characterized in that it is configured to be
According to claim 1,
In the upstream of the degassing tower 200, a chemical is added to wastewater in the reaction tank 11, agitated by the stirrer 12 to agglomerate foreign substances, and the foreign substances are suspended or precipitated by the swash plate 13 to separate them and then a treatment tank A pretreatment means (100) for adding and storing sodium hydroxide for pH adjustment suitable for degassing (15);
At the downstream of the electrolysis means 400, a post-treatment means 500 for discharging the exhaust gas from the lower part of the tower to the upper part and spraying the washing water from the upper part to the lower part of the tower to remove the residual odor of the exhaust gas. Ammonia treatment device for wastewater characterized by

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