KR20160003936A - Nitrogen removal, recovery apparatus and method thereof - Google Patents

Abstract

The present invention relates to an apparatus for removing and collecting nitrogen, and a method thereof, wherein the collecting apparatus comprises: a deairing tank having an ultra-fine bubble device; an alkaline washing tower; an acidic washing tower; a zeolite reactor; and a MAP reactor which produces particulate MAP through a MAP reaction.

Description

[0001] NITROGEN REMOVAL, RECOVERY APPARATUS AND METHOD [0002]

The present invention relates to a nitrogen removal, recovery apparatus and a method thereof, and more particularly, to a zeolite fertilizer which can produce a slow-acting high-purity zeolite fertilizer by using zeolite for ammonium ion adsorption and removal, And can also recover the effective resources by producing the granular MAP fertilizer through the MAP determination generated by utilizing the components eluted from the zeolite and can greatly reduce the amount of the chemicals required for the MAP reaction. It is about the method.

Phosphorus, which is one of the essential elements of plant growth, is used as fertilizer. It is absorbed into agricultural products and is finally contained in manure via human body or livestock, or contained in wastewater via chemical plants, It is also a pollutant source that discharges to the same closed waters and causes eutrophication of rivers. It is important to reclaim resources from rivers, wastewater, and livestock manure wastewater at the time when the amount of phosphorus is buried in a limited number of countries globally and the amount of phosphorus is increased every year by industrial development .

Phosphorus removal and recovery methods are generally divided into biological treatment methods and chemical methods using coagulants. In biological removal, stable phosphorus removal is difficult and chemical removal is stable. However, a large amount of sludge is generated and used Which increases processing cost.

In addition, a general method of treating phosphorus is to treat it by chemical treatment in the bottom, wastewater and livestock manure wastewater and solidify it in the form of phosphate. However, if the sludge is not suitable for reuse due to impurities, moisture content, And most of them are landfilled. However, due to the various sediments occurring during physical and chemical treatment to remove impurities in the wastewater and wastewater wastewater wastewater treatment process, many useful substances including phosphorus are distributed in the sludge, Recycling is important. In addition, conventional phosphorus removal and recovery methods induce MAP reaction only in the case of inducing MAP reaction, and by applying a method of recovering crystals having a predetermined size or more by installing a collecting device at the lower end of the MAP reaction tank, The techniques are based on only soluble (20 ~ 30% of the total) present in the wastewater, and the crystals produced by inducing MAP are also very few, and those produced below a certain size are not precipitated to the bottom, And the recovery rate was very low. Particularly, at the end of the MAP reaction, a biological treatment process for removing phosphorus separately or a chemical flocculation facility was required.

In addition, prior to modern times, nutrients such as manure and wastewater were recognized as fertilizer and the resource circulation linking to farmland was formed. However, an attempt was made to reproduce the circulation loop that was broken due to the spread of sewerage in terms of waste disposal and resource recycling And to reduce the use of chemical fertilizers by promoting fertilization of sludge and others, thereby reducing the outflow load to rivers and reducing the import volume of phosphorus imported from foreign countries. It is important to focus on the development of an economical and efficient process that takes into account the ease of recycling from the simple phosphorus removal process so far.

On the other hand, when the anaerobic digestion capacity is small and the amount of digestion decant fluid is small, the concentration of the digestion decant fluid may be lowered by using a dilution method and then directly discharged or linked with a sewage treatment plant, A method of direct utilization of the liquid fertilizer to agricultural land can be used. When the amount of anaerobic digestion liquor to be treated is large, ammonia degassing, sedimentation / flocculation method, direct sewage treatment method and the like can be used. However, the treatment of digestive decantation by dilution method, which is used when the anaerobic digestion capacity is small, can cause eutrophication of nitrogen in the surrounding rivers in the long term and can cause nitrogen pollution in the soil when used directly as a liquid fertilizer on agricultural land The problem is that odor is generated by unremoved ammonia. In addition, in the case of large-scale digestion liquor, there is a considerable concentration of ammonia, and in case of anaerobic digestion of livestock manure, the odor generated due to the large amount of ammonia gas is also required to be treated.

Ammonia is generated when decomposition of animal carcasses such as carcasses and excreta, and is released in plant effluent and other sewage in large quantities. The concentration of ammonia in water acts as an indicator of water pollution, and the nitrogen compound in water itself Is not only a cause of destruction of water ecosystem and loss of water value as a pollutant, but it causes eutrophication phenomenon, which further deteriorates water quality. For this reason, it is urgent to develop a technique for effectively removing ammonia from wastewater. Although biological denitrification is generally used in many water treatment facilities for treating such high concentration ammonia nitrogen-containing wastewater, when ammonia nitrogen is present at a high concentration such as livestock manure, the activity of microorganisms is inhibited by ammonia toxicity, An increase in capacity, and an external carbon source requirement for C / N ratio adjustment.

In addition, the biggest problem of domestic livestock manure wastewater treatment facility is that the actual incoming livestock manure contains high concentration nitrogen and high concentration, which significantly exceeds the treatment capacity. As the environmental standard is strengthened day by day, As well as strict nitrogen and phosphorus treatment are required.

As disclosed in Korean Patent Laid-Open Publication No. 10-2012-0078819 (published on Jul. 11, 2012, Ammonia Stripping Apparatus for Wastewater), ammonia is removed from wastewater such as food or livestock waste, The pH of the wastewater is adjusted by using chemicals such as lime and caustic soda and the ammonia is removed from the wastewater by contacting the wastewater which has undergone temperature and pressure control with the air and the efficiency of air contact by ejection and atomization of the wastewater This also has limitations in the amount of chemicals used, the recovery of effective resources, and the recovery rate of ammonia.

Korean Patent Publication No. 10-2012-0078819 (titled ammonia stripping apparatus of wastewater)

SUMMARY OF THE INVENTION The present invention has been made to overcome the above problems, and it is an object of the present invention to provide a zeolite fertilizer which can produce a slow-acting high purity zeolite fertilizer by using zeolite for ammonium ion adsorption and desorption, And can recover the effective resources by producing the granular MAP fertilizer through the MAP determination generated by utilizing the components eluted from the zeolite and can greatly reduce the amount of the chemicals required for the MAP reaction. And a method therefor.

Another object of the present invention is to provide a nitrogen removing and recovering apparatus and a method thereof capable of recycling environmental pollutants such as alkaline waste liquid and washed waste acid that can occur in the present process.

In order to achieve the above-mentioned object, the present invention provides a super-high-strength packaging device for converting ammonium ion (NH ₄ ⁺ ) into ammonia (NH ₃ ) capable of deaeration when wastewater containing high concentration ammonia nitrogen is introduced Deaeration; An alkaline scrubbing tower in which deaerated ammonia gas flows in the degassing vessel and caustic soda (NaOH) is added to deodorize the ammonia; Ammonia gas is introduced from the alkaline scrubbing column and ammonia in the gas is recovered as ammonium sulfate or ammonium phosphate by injecting sulfuric acid (H ₂ SO ₄ ) or phosphoric acid (H ₃ PO ₄ ) aqueous solution to remove ammonia in the gas tower; A zeolite reaction tank in which ammonium sulfate or ammonium phosphate discharged from the acid scrubber is introduced and ammonium is replaced with zeolite to adsorb and remove ammonium ions; And a MAP reaction tank in which a waste liquid generated from the zeolite reaction tank (including Ca ^{2 +} , Mg ^{2 +} , phosphoric acid, and ammonia released from the zeolite) flows and produces granular MAP through MAP reaction, .

Further, the present invention is characterized in that an alkaline agent or an alkaline waste liquid generated in the alkaline cleaning tower is injected into the degassing vessel for increasing the pH.

In addition, the present invention can prevent ammonia from being removed from the pickling column, and exhaust gas having a reduced odor discharged to the outside, thereby preventing nitrogen contamination due to release of ammonia gas in the atmosphere during ammonia degassing.

Also, the present invention is characterized in that caustic soda (NaOH), phosphoric acid, and MgCl ₂ are added to improve the MAP reaction efficiency in the MAP reaction tank.

The present invention also relates to a method for converting ammonia (NH ₄ ⁺ ) into ammonia (NH ₃ ) capable of degassing when wastewater containing high-concentration ammonia nitrogen is introduced into a deaeration tank provided with a super-strength package, Degassing the ammonia; (b) introducing ammonia gas deaerated in the degassing vessel into an alkaline scrubbing column, and adding caustic soda (NaOH) to the alkaline scrubbing column to deodorize the ammonia; (c) ammonia gas flows into the acid scrubber from the alkaline scrubbing column, and an aqueous solution of sulfuric acid (H ₂ SO ₄ ) or phosphoric acid (H ₃ PO ₄ ) is fed into the acid scrubber column to remove ammonia in the gas from ammonium sulfate or ammonium phosphate To remove ammonia in the gas; (d) introducing ammonium sulfate or ammonium phosphate discharged from the acid scrubbing column into a zeolite reaction tank, and replacing ammonium with zeolite in a zeolite reaction tank to adsorb and remove ammonium ions; And (e) a waste liquid generated from the zeolite reaction tank (including Ca ^{2 +} and Mg ^{2 +} , phosphoric acid, and ammonia released from the zeolite) flows into the MAP reaction tank, and MAP- The method comprising the steps of:

Further, the present invention is characterized in that in the step (a), an alkaline agent or an alkaline waste liquid generated in the alkaline cleaning tower is injected into the degassing vessel for increasing the pH.

Further, in the step (c), ammonia is removed from the pickling column in the step (c), and the exhaust gas whose odor is reduced is discharged to the outside, thereby preventing nitrogen contamination due to release of ammonia gas in the atmosphere during ammonia degassing.

Also, in the step (e), caustic soda (NaOH), phosphoric acid and MgCl ₂ are added to improve MAP reaction efficiency in the MAP reaction tank.

As described above, the nitrogen removal and recovery apparatus and the method of the present invention can produce slow-acting high-purity zeolite fertilizer by using zeolite for ammonium ion adsorption removal and can increase ammonia removal and recovery rate by applying a two- In addition, it is possible to recover the effective resources by also producing the granular MAP fertilizer through the MAP crystals generated by utilizing the components eluted from the zeolite, and to greatly reduce the amount of the chemicals required for the MAP reaction, And environmental pollutants such as washing waste acid can be recycled.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a block diagram of a nitrogen removal and recovery device. FIG.
2 is a block diagram of the phosphorus removal and recovery device.
FIG. 3 is a schematic view of a nitrogen and phosphorus removal and recovery device, in which FIG. 1 and FIG. 2 are combined in one system. FIG.
4 is a flow chart of a nitrogen removal and recovery method.
5 is a flow chart of the phosphorus removal and recovery method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings and description thereof are simplified and illustrated to enable those of ordinary skill in the art to understand the present invention, You will not understand.

Phosphorus dissolved in streams, wastewater, and livestock manure wastewater discharged from various routes is mainly present in the form of phosphate ion (PO ₄ ^- ) or precipitated phosphate. The present invention can be applied to such livestock manure and digestion liquor, The present invention relates to an apparatus for removing phosphorus from wastewater containing a high concentration of phosphorus such as a liquid fertilizer and the like. The apparatus includes a membrane filter A solubilization tank 20, a secondary MAP reaction tank 30, and a recovery / separation device 40, which are combined with a magnesium MAP (Magnesium Ammonium Phosphate) ammonium phosphate reaction tank 10 and a solubilizing device including ultrasonic cavitation And a membrane filter is installed in the primary MAP reaction tank 10 so that suspended solids (SS) and particulate matter are introduced into the system (primary MAP reaction tank, solubilization tank, secondary MAP reaction tank, recovery / Physical Unit) is a closed circular structure only on circulating within.

First, in the first MAP reaction tank 10 equipped with a membrane filter, the MAP reaction (Mg (O)) in which dissolved phosphorus (PO ₄ ^{3 -} -P) existing in wastewater flowing into the primary MAP reaction tank 10 is combined with ammonium and magnesium : NH ₄ : PO ₄ 1: 1: 1 molar ratio reaction). In this case, since the concentration of magnesium in the wastewater is generally higher than that of ammonium in the order of dissolved < ammonium, &gt; magnesium compounds such as MgCl ₂ should be added in order to convert all dissolved phosphorus to MAP crystal. On the other hand, in order to convert all the ammonium present in wastewater into MAP crystal crystals, dissolved phosphorus such as phosphoric acid (H ₃ PO ₄ ) is added in addition to magnesium substances such as MgCl ₂ . In order to improve the reaction efficiency by increasing the pH, the alkaline substance such as NaOH is added or the carbon dioxide is removed from the water by aeration to remove the pH . Here, a pH automatic regulator may be operated to inject an appropriate amount of an alkali agent such as NaOH.

In other words, ammonium ions, magnesium ions and phosphate ions at a high concentration react with each other at a suitable pH to precipitate MAP (MgNH ₄ PO ₄ .6H ₂ O, struvite) as shown in the following reaction formula. Since the ratio of magnesium, ammonium, and phosphate is 1: 1: 1, magnesium should be continuously added to most of the treated water with low magnesium concentration. The precipitated and recovered MAP is a useful form of phosphorus compound that can be used as a fertilizer without further treatment and the MAP is a magnesium-ammonium-phosphate type material that can be recovered in its best form in the treatment of wastewater and animal wastewater wastewater. Since it also contains nitrogen, it is very suitable for use as a slow-release fertilizer.

In the first MAP reaction tank 10, the MAP reaction is induced for a predetermined time according to the concentration and pH of the dissolved phosphorus, and MAP reaction in the first MAP reaction tank 10 is performed through a membrane filter installed in the first MAP reaction tank 10 The SS and the particulate matter containing phosphorus in the wastewater are removed from the system (primary MAP) by the operation of the pump using an outflow pipe connected to a pump (not shown) And the dissolved phosphorus is transformed into crystal crystals through the MAP reaction and precipitates. As a result, dissolved phosphorus and particulate phosphorus components are formed in the effluent through the membrane filter So that no loss is caused. Reference numeral 52 denotes a treatment water tank in which effluent water is stored, but the effluent water may be discharged in a subsequent process or may be discharged to a river or the like.

Next, in the solubilization tank 20 to which the solubilizing device is coupled, MAP crystal crystals remaining in the first MAP reaction tank 10, SS and particulate matter are contained after the MAP reaction-treated wastewater flows out through the membrane filter The sludge is introduced with the MAP crystal crystals in order to convert the particulate phosphorus present in the sludge containing SS and particulate matter into dissolved phosphorus before the sludge moves to the secondary MAP reactor 30 Sludge solubilizing devices such as ultrasound cavitation and the like are generally devices for destroying the cell walls of microorganisms to reduce sludge or improve the productivity of biogas and can convert particulate phosphorus to soluble phosphorus .

Next, in the second MAP reaction tank 30, the particulate phosphorus is converted into substantially soluble phosphorus by passing through the solubilization tank 20, and flows together with the MAP crystal crystals and the sludge. Magnesium (MgCl ₂ ), phosphoric acid (H ₃ PO ₄ ), and NaOH are introduced into the secondary MAP reaction tank 30 to induce a secondary MAP reaction in the same manner as in the primary MAP reaction tank 10. Here, the MAP crystal crystals generated in the first MAP reaction tank 10 can grow through an additional secondary MAP reaction.

Next, the MAP crystal crystals generated and grown through the first and second MAP reaction vessels 10 and 30 pass through a collecting and separating device 40 such as a sieve, MAP crystal crystals having a size equal to or greater than the MAP crystal size are utilized as granular MAP fertilizers, and the MAP crystal crystals having a certain size or less are introduced into the first MAP reaction tank together with the remaining sludge. Therefore, MAP crystal crystals grow to such an extent that they can be utilized as granular MAP fertilizers by repeatedly circulating the first MAP reaction tank, the solubilization tank, the second MAP reaction tank, and the recovery / separation device, do.

Accordingly, the present invention is characterized in that a membrane filter is installed in the primary MAP reaction tank 10 to prevent the outflow of particulate phosphorus, and the solubilization tank 20 in which the solubilization apparatus is combined is installed to convert the particulate phosphorus to the dissolved phosphorus MAP reaction (secondary MAP reaction tank), it is possible not only to remarkably improve the removal and recovery rate as compared with the prior art, but also to produce a slow-acting high-purity MAP fertilizer, and in particular, However, the present invention can greatly reduce the amount of medicines used compared to the prior art in a closed circulation type. In addition, there is no separate biological treatment facility or chemical flocculation facility to remove phosphorus because there is no dissolved phosphorus and particulate phosphorus in the effluent.

Hereinafter, as shown in FIG. 5, the phosphorus removal and recovery method according to the phosphorus removal and recovery apparatus will be described together with the operation thereof.

First, MAP crystals are generated through MAP reaction in which dissolved phosphorus and magnesium present in the wastewater flowing into the first MAP reaction tank 10 in the first MAP reaction tank 10 equipped with a membrane filter are coupled (S100).

Next, the MAP reaction is induced for a predetermined time according to the concentration and pH of the dissolved phosphorus in the first MAP reaction tank 10, and then the MAP reaction is performed in the first MAP reaction tank 10 through a membrane filter installed in the first MAP reaction tank 10 The MAP treated wastewater is discharged (S110).

Next, after the MAP reaction-treated wastewater flows out through the membrane filter, MAP crystals remaining in the primary MAP reaction tank 10 and sludge containing SS and particulate matter are introduced into a solubilization tank 20 in the sludge containing SS and particulate matter in the solubilization tank 20 (S120).

Next, the sludge and MAP crystals, which have been converted into substantially soluble phosphorus, are introduced into the secondary MAP reaction tank 30 through the solubilization tank 20, and 2 A MAP MAP reaction is induced to grow MAP crystals generated in the first MAP reaction tank 10 (S130).

Next, the MAP crystals having a predetermined size or greater generated and grown through the first and second MAP reaction tanks 10 and 30 are filtered by the recovery / separation unit 40 (S140).

In addition, MAP crystals of a predetermined size or smaller are introduced into the first MAP reaction tank 10 in step S100 together with the remaining sludge in the step S140, and the MAP reaction is performed in the first MAP reaction tank, the solubilization tank, the second MAP reaction tank, By cycling the apparatus repeatedly, MAP crystals grow to such an extent that they can be utilized as granular MAP fertilizers, thereby increasing the phosphorus recovery rate.

In step S100 or step S130, magnesium or dissolved phosphorus may be added according to the concentration of dissolved phosphorus or ammonium present in the wastewater. In order to improve the MAP reaction efficiency by increasing the pH, an alkaline substance may be added It is possible.

It is another object of the present invention to solve the problem of deterioration of treatment efficiency due to lowered water temperature in the winter season of a degassing apparatus for removing or recovering nitrogen in wastewater containing high nitrogen concentration and to improve the adsorption rate of ammonia in the degassing gas, 1, a degassing vessel 50, an alkali washing tower 60, an acid washing tower 70, a zeolite reaction vessel 80, and a MAP And a reaction tank (90).

First, the degassing vessel (50) in which the wastewater flows into the ultra-high-strength vessel (51) is formed with micro-bubbles due to the ultra-high strength packing as compared with the conventional degassing vessel, And the maintenance cost is reduced. In addition, it is preferable that the degassing vessel 50 can minimize external heat loss, thereby preventing the degassing efficiency from lowering due to a decrease in water temperature.

In the deaeration tank 50, ammonia in the wastewater is deaerated. That is, the ammonia contained in the wastewater is separated and discharged by air. In the present invention, the wastewater having a high pH is blown into the ultra- Method. Here, lime, alkaline agents such as NaOH and Ca (OH) ₂ are injected into the wastewater and livestock manure wastewater containing high concentration ammonia nitrogen, and the pH is adjusted to a high range of 10.5 to 11.5, ₄ ⁺ ) into ammonia (NH ₃ ), which can be degassed, and the generated free ammonia is brought into contact with the surface of the air or vapor to volatilize it with the organic substances in the wastewater. Reference numeral 52 denotes a treatment water tank in which effluent water from the degassing vessel is stored, but the effluent water may be discharged in a subsequent process or may be discharged to a river or the like.

As shown in FIG. 3, the deaeration basin 50 allows the effluent water flowing through the membrane filter in the primary MAP reaction tank 10 to be evacuated to remove ammonia in the effluent water, The treated water may be discharged.

Next, in the alkaline scrubbing column 60 into which the deaerated ammonia gas is introduced from the degassing vessel 50, caustic soda (NaOH) is added for the purpose of deodorization by the irreversible chemical reaction between the odor component of ammonia and the main component of the nutrient solution And the alkaline waste liquid generated therein can be utilized as a pH adjusting agent of the degassing vessel 50. [

In addition, the alkaline washing column 60 may be connected to allow natural ammonia gas generated in the first MAP reaction tank 10 or ammonia gas deaerated by the washing air to flow in the course of washing the membrane filter.

Subsequently, an aqueous solution of sulfuric acid (H ₂ SO ₄ ) or phosphoric acid (H ₃ PO ₄ ) is introduced into the acid scrubbing column 70 into which the ammonia gas flows from the alkali scrubbing column 60, Ammonia in the gas is recovered and recovered as ammonium phosphate to eliminate the odor-reducing flue gas to be discharged to the outside, and nitrogen poisoning due to release of ammonia gas in the atmosphere during ammonia deaeration can be solved. Here, the wasted acid generated in washing the membrane filter in the primary MAP reaction tank 10 may be used as an ammonia absorbent.

Ammonium sulfate or ammonium phosphate discharged from the pickling column 70 flows into a zeolite reaction tank 80. The zeolite reaction tank 80 converts ammonium into zeolite to produce a zeolite fertilizer, Is very suitable for use as a slow-release fertilizer, and the recovery rate can be adjusted by constructing multiple zeolite layers. Here, zeolite is an aluminum silicate mineral containing sodium and potassium alkali metals, alkaline earth metals such as calcium and magnesium, and containing crystal water, and is a wastewater having a high removal rate of heavy metals in wastewater and a high concentration of ammonia nitrogen The organic material and nitrogen can be removed at the same time. In the zeolite reaction tank 80, it is used for the purpose of adsorbing and removing ammonium ions. Accordingly, in the present invention, the absorption amount of ammonium increases with the application of the two-stage ammonia absorption tower (acid washing tower and zeolite reaction tank).

Finally, the waste liquid generated from the zeolite reaction tank 80 (including Ca ^{2 +} and Mg ^{2 +} , phosphoric acid, and ammonia released from the zeolite) flows into the MAP reaction tank 90 to remove ammonia remaining in the ammonium sulfate or ammonium phosphate MAP MAP is produced through MAP reaction. In the MAP reaction tank 90, caustic soda (NaOH), phosphoric acid, and MgCl ₂ are added in order to improve MAP reaction efficiency. In the zeolite reaction tank 80, Mg ^{2 +} ions are eluted during the substitution of gaseous ammonium Accordingly, the amount of magnesium drug compared to the conventional MAP process can be reduced. The granular MAP produced in the MAP reaction tank 90 can be utilized as a granular MAP fertilizer. If the granular MAP fertilizer is to be produced more than the zeolite fertilizer in the present process, the ammonium substitution rate in the zeolite is reduced, The amount of MAP crystals will increase due to the reaction with residual phosphoric acid after replacement of ammonium in Mg ^{2 +} and ammonium phosphate eluted from the zeolite.

Further, the zeolite reaction tank 80 as shown in Figure 3 is the inlet for phosphoric acid in the Mg ^{2 +} and ammonium phosphate is coupled to the second MAP reaction tank 30, which is eluted from the zeolite in the second MAP reactor (30) So as to induce MAP reaction. This MAP reaction is advantageous in that it can remove nitrogen and phosphorus simultaneously and removes a considerable amount of organic nitrogen which was impossible in ammonia degassing since a considerable amount of solids is removed during the precipitation process. In this process, separate high concentration ammonia There is an additional advantage that the injection of phosphoric acid, magnesium ions can be reduced.

Hereinafter, as shown in FIG. 4, the nitrogen removal and recovery method according to the nitrogen removal and recovery apparatus will be described in conjunction with the operation thereof.

First, when wastewater containing high-concentration ammonia nitrogen is introduced into the degassing vessel 50 equipped with the ultra-high-strength pavement 51, the ammonium ion (NH ₄ ⁺ ) is converted into ammonia (NH ₃ ) Deg.] (S200).

Next, the deaerated ammonia gas in the degassing vessel 50 flows into the alkali scrubbing column 60, and caustic soda (NaOH) is introduced into the scrubbing column 60 to deodorize the ammonia (S210).

Ammonia gas flows into the acid scrubber 70 from the alkaline scrubber 60 and an aqueous solution of sulfuric acid (H ₂ SO ₄ ) or phosphoric acid (H ₃ PO ₄ ) is introduced into the acid scrubber 70 Ammonia in the gas is recovered as ammonium sulfate or ammonium phosphate to remove ammonia in the gas (S220).

Ammonium sulfate or ammonium phosphate discharged from the acid scrubbing tower 70 flows into the zeolite reaction tank 80 and ammonium is replaced with zeolite in the zeolite reaction tank 80 to adsorb and remove ammonium ions S230).

Next, the waste liquid generated from the zeolite reaction tank 80 (including Ca ^{2 +} , Mg ^{2 +} , phosphoric acid, and ammonia released from the zeolite) flows into the MAP reaction tank 90, The granular MAP is produced through the reaction (S240).

In addition, the alkaline agent or the alkali waste liquid generated in the alkaline cleaning tower 60 may be injected into the degassing vessel 50 for increasing the pH in step S200. In step S220, ammonia And the smell-reduced exhaust gas is discharged to the outside to prevent nitrogen pollution due to the release of ammonia gas in the atmosphere during ammonia degassing. In order to improve MAP reaction efficiency in the MAP reaction tank 90 in step S240, Caustic soda (NaOH) and phosphoric acid, MgCl ₂ may also be added.

As a pretreatment step in step S200, effluent water through the membrane filter in the first MAP reaction tank 10 is introduced into the degassing vessel 50, so that ammonia in the effluent water is degassed to remove phosphorus and nitrogen from the degassing vessel 50 The treated water may be discharged.

In addition, the zeolite reaction tank 80 is introduced to acid in the MAP reaction vessel 90 instead of the second MAP is connected to the reaction tank 30, the second MAP Mg ^{2 +} and ammonium phosphate eluted from the zeolite in the reaction vessel 30 So as to induce MAP reaction.

10: primary MAP reaction tank 20: solubilization tank
30: secondary MAP reaction tank 40: recovery / separation device
50: Melting tank 51: Ultra-high-strength packaging
52: Treatment tank 60: Alkali cleaning tower
70: Acid cleaning tower 80: Zeolite reaction tank
90: MAP reaction tank

Claims (8)

A degassing vessel (50) provided with ultra-high-strength packings for converting ammonium ions (NH ₄ ⁺ ) into ammonia (NH ₃ ) capable of degassing when wastewater containing high-concentration ammonia nitrogen is introduced;
An alkaline scrubbing tower 60 into which degassed ammonia gas flows in the degassing vessel 50 and caustic soda (NaOH) is added to deodorize the ammonia;
Ammonia gas is introduced from the alkaline scrubbing column 60 and ammonia in the gas is recovered as ammonium sulfate or ammonium phosphate by injecting sulfuric acid (H ₂ SO ₄ ) or phosphoric acid (H ₃ PO ₄ ) aqueous solution to remove ammonia An acid scrubbing tower 70;
A zeolite reaction tank 80 in which ammonium sulfate or ammonium phosphate discharged from the acid scrubbing tower 70 is introduced and ammonium is replaced by zeolite to adsorb and remove ammonium ions; And
A MAP reaction tank 90 into which a waste liquid generated from the zeolite reaction tank 80 (including Ca ²⁺ and Mg ^{2 +} , phosphoric acid, and ammonia released from zeolite) flows and produces a granular MAP through MAP reaction; &Lt; / RTI &gt; The method according to claim 1,
characterized in that an alkaline agent or an alkaline waste liquid generated in the alkaline cleaning tower (60) is injected into the degassing vessel (50) for increasing the pH. The method according to claim 1,
The nitrogen removal and recovery device according to claim 1, wherein ammonia is removed from the acid scrubbing column (70) and exhaust gas having a reduced odor is discharged to the outside to prevent nitrogen contamination due to release of ammonia gas in the atmosphere during ammonia degassing. The method according to claim 1,
Characterized in that caustic soda (NaOH), phosphoric acid, and MgCl ₂ are added to the MAP reaction tank (90) to improve MAP reaction efficiency. (a) When wastewater containing a high concentration of ammonia nitrogen flows into the degassing vessel 50 equipped with the ultra-high-strength pavement 51, the ammonium ion (NH ₄ ⁺ ) is converted into ammonia (NH ₃ ) Degassing the ammonia in the wastewater;
(b) introducing ammonia gas deaerated in the degassing vessel 50 into the alkaline scrubbing column 60 and adding caustic soda (NaOH) to the alkaline scrubbing column 60 to deodorize the ammonia;
(c) The ammonia gas is introduced into the acid scrubbing column 70 from the alkali scrubbing column 60 and an aqueous solution of sulfuric acid (H ₂ SO ₄ ) or phosphoric acid (H ₃ PO ₄ ) is introduced into the acid scrubbing column 70 Recovering the gaseous ammonia into ammonium sulfate or ammonium phosphate to remove ammonia in the gaseous phase;
(d) introducing ammonium sulfate or ammonium phosphate discharged from the acid scrubbing tower 70 into the zeolite reaction tank 80, replacing ammonium with zeolite in the zeolite reaction tank 80 to adsorb and remove ammonium ions; And
(e) The waste liquid generated from the zeolite reaction tank 80 (including Ca ^{2 +} , Mg ^{2 +} , phosphoric acid, and ammonia released from the zeolite) flows into the MAP reaction tank 90, To produce a granular MAP through the granulation process. &Lt; RTI ID = 0.0 &gt; 18. &lt; / RTI &gt; 6. The method of claim 5,
Wherein the alkaline agent or the alkali waste liquid generated in the alkaline cleaning tower (60) is injected into the degassing vessel (50) for increasing the pH in the step (a). 6. The method of claim 5,
In the step (c), ammonia is removed from the acid scrubbing column (70), and the exhaust gas whose odor is reduced is discharged to the outside to prevent nitrogen contamination due to release of ammonia gas in the atmosphere during ammonia degassing. Recovery method. 6. The method of claim 5,
Wherein the step (e) comprises adding caustic soda (NaOH), phosphoric acid, and MgCl ₂ to the MAP reaction tank 90 to improve MAP reaction efficiency.

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