JP3637458B2 - Ammonia nitrogen removal method - Google Patents

Ammonia nitrogen removal method Download PDF

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JP3637458B2
JP3637458B2 JP06184595A JP6184595A JP3637458B2 JP 3637458 B2 JP3637458 B2 JP 3637458B2 JP 06184595 A JP06184595 A JP 06184595A JP 6184595 A JP6184595 A JP 6184595A JP 3637458 B2 JP3637458 B2 JP 3637458B2
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chamber
ions
concentration
exchange membrane
ammonia
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JPH08229568A (en
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哲男 杉村
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Toshiba Plant Systems and Services Corp
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Description

【０００１】
【産業上の利用分野】
本発明は火力発電プラントにおける復水脱塩再生水などの液中に存在するアンモニア性窒素をアンモニアガスとして除去する方法に関する。
【０００２】
【従来の技術】
例えば火力発電プラントにおける復水などは、通常イオン交換樹脂により脱塩されて復水脱塩再生水とされるが、その再生水中には一般に環境基準を越える量のアンモニア性窒素が含まれている。従来からこのような復水脱塩再生水中のアンモニア性窒素を環境基準以下に低減する方法として、アンモニア拡散（ストリッピング）法が多用されている。
【０００３】
【発明が解決しようとする課題】
しかしこのストリッピング法は、複雑な設備や大きな敷地面積を必要とする上に、多大のエネルギーを消費するという問題がある。また、大気中に蒸発水と共にアンモニアを放出させることは環境上も好ましくないので、それを回避するためにはさらに後処理設備を必要とするが、そのような設備を設けても資源としてのアンモニアを回収することは容易ではない。
そこで本発明はこのような問題を解決するためのアンモニア性窒素の除去方法の提供を課題とするものである。
【０００４】
【課題を解決するための手段】
本発明は、アンモニア性窒素を含有する液に酸を添加してアンモニウム塩を沈澱除去し、得られたアンモニウムイオンを含む液を陽イオン交換膜と陰イオン交換膜が交互に配置された電気透析装置で処理するアンモニア性窒素の除去方法である。
そして電気透析装置の透析単位として、アンモニウムイオンを含む液を導入する希釈室と、その希釈室の陽イオン交換膜側に隣接する第１濃縮室と、希釈室の陰イオン交換膜側に隣接する第２濃縮室と、第１濃縮室の陰イオン交換膜側に隣接して水酸イオン含有液が流れる水酸イオン室を含む。さらに第１濃縮室のｐＨは、希釈室より移動するアンモニウムイオンと水酸イオン室から移動する水酸イオンからアンモニアを生成する平衡条件となるようなアルカリ性に維持する。そして生成したアンモニアを気体として第１濃縮室から取り出すことを特徴とするものである。
【０００５】
【実施例】
次に、本発明のアンモニア性窒素の除去方法をさらに詳細に説明する。
図１は本発明のアンモニア性窒素の除去方法を実施するための処理フローシートの一例であり、１はｐＨ調整槽、２はポンプ、３は中空糸膜フイルタ、４は電気透析装置である。
アンモニア性窒素を含有する液ａは、ｐＨ調整槽１で添加される酸ｂと混合され、ｐＨを４以下、好ましくは２〜４程度に調整され、それによってアンモニア性窒素はアンモニウム塩として沈澱し配管ｃから除去される。添加する酸としては鉱酸、例えば塩酸または硫酸などが好ましい。沈澱しないアンモニウムイオン（ＮＨ4 イオン）と無機イオン、例えば酸として硫酸を使用するときは硫酸イオン（ＳＯ4 イオン）が液中に残される。
ｐＨ調整槽１からのアンモニウムイオンを含む液は、ポンプ２により配管ｄを通って中空糸膜フイルタ３に送られて微細な固形粒子が除去される。固形粒子を除去することにより電気透析装置における透析膜の有効処理時間を大幅に延長することができる。
【０００６】
固形粒子を除去した再生水は、配管ｅにより電気透析装置４の希釈室に導入され、そこで電気透析処理により一定量のアンモニアイオンおよびその他の無機イオン類を低減された液が配管ｆを通って排出され、再使用するか系外に放出される。
電気透析装置４は後述するように陽イオン交換膜と陰イオン交換膜が交互に多数配置され、それらによって仕切られた希釈室、第１濃縮室、第２濃縮室および水酸イオン室が透析単位となっている。そして水酸イオン室に水酸イオン供給液としての水酸化ナトリウム（ＮａＯＨ）を含む液が配管ｇにより導入され、配管ｈから流出する。さらに第１濃縮室には室内を高ｐＨに維持するためにアルカリ剤を含む液、例えば水酸化ナトリウム（ＮａＯＨ）液が配管ｋにより導入され、第１濃縮室からはＮａＯＨ液が配管ｍにより流出する。また気体としてのアンモニアが第１濃縮室内を上昇して配管ｉから外部に取り出される。さらに第２濃縮室で濃縮されたＳＯ4 イオンのような無機イオンとＮａイオンを含む液が配管ｊから流出する。
【０００７】
次に、図２は本発明に使用される電気透析装置４を模式的に示す図である。例えばチタン板に白金メッキした陽極板５と、ステンレス板からなる陰極板６との間に陽イオン交換膜Ｃと陰イオン交換膜Ａが交互に多数配置される。陰イオン交換膜Ａとしては、例えばイオン交換基として４級アンモニウム塩を１．５〜３．０（ｍｅｑ／ｇ乾燥樹脂）含むスチレン／ジビニルベンゼン共重合体系の膜が使用され、陽イオン交換膜Ｃとしては、例えばイオン交換基としてスルホン酸基を１．５〜３．０（ｍｅｑ／ｇ乾燥樹脂）含むスチレン／ジビニルベンゼン共重合体系の膜が使用される。なお陽極板５とそれに隣接する陰イオン交換膜Ａとの間には陽極液が流され、陰極板６とそれに隣接する陽イオン交換膜Ｃとの間には陰極液が流される。
【０００８】
イオン交換膜の対数は液中に含まれるアンモニアイオンの濃度や所望の処理量等により異なるが、一般に２００〜９００対程度用いられる。そして一対の陽イオン交換膜Ｃと陰イオン交換膜Ａの間にアンモニウムイオンを含む液を導入する希釈室１０が配置され、希釈室１０の陽イオン交換膜Ｃ側に隣接して第１濃縮室１１、希釈室１０の陰イオン交換膜Ａ側に隣接して第２濃縮室１２が配置され、さらに第１濃縮室１１の陰イオン交換膜Ａ側に隣接して水酸イオン含有液が流れる水酸イオン室１３が配置されている。そしてこれら希釈室１０、第１濃縮室１１、第２濃縮室１２および水酸イオン室１３により透析単位Ｕが構成され、そのような透析単位が陽極板５と陰極板６との間に多数配置されている。
【０００９】
前述のように酸として硫酸を用いた場合は、希釈室１０にはアンモニウムイオン（ＮＨ4 イオン）と硫酸イオン（ＳＯ4 イオン）を含む液が配管ｅにより導入され、そこでこれらイオンは陰−陽極板間に形成された電場によって電気的に泳動する。ＮＨ4 イオン（陽イオン）は陰極板６の方向に泳動し、陽イオン交換膜Ｃを透過し第１濃縮室１１に移動する。第１濃縮室１１内のＮＨ4 イオンはさらに陰極板６方向へ泳動しようとするが、水酸イオン室１３との境界の陰イオン交換膜Ａに阻止される。
一方ＳＯ4 イオン（陰イオン）は陽極板５の方向に泳動し、陰イオン交換膜Ａを透過して第２濃縮室１２に移動する。第２濃縮室１２内のＳＯ4 イオンはさらに陽極板５方向に泳動しようとするが、次の透析単位を構成する水酸イオン室１３との境界の陽イオン交換膜Ｃに阻止されて濃縮液中に残る。このように希釈室１０のＮＨ4 イオンは第１濃縮室１１へ移動し、ＳＯ4 イオンは第２濃縮室１２に移動する。
【００１０】
配管ｇにより図示中央の水酸イオン室１３に導入された水酸化ナトリウムを含む液は、陽イオンであるナトリウムイオン（Ｎａイオン）と陰イオンである水酸イオン（ＯＨイオン）とに電離される。陰−陽極板間に形成された電場によって、Ｎａイオンは陰極板６の方向に泳動し、陽イオン交換膜Ｃを透過し次の透析単位を構成する第２濃縮室１２に移動する。第２濃縮室１２内のＮａイオンはさらに陰極板６方向へ泳動しようとするが陰イオン交換膜Ａに阻止される。
一方、ＯＨイオンは陽極板５の方向に泳動し、陰イオン交換膜Ａを透過して第１濃縮室１１に移動する。第１濃縮室１１内のＯＨイオンはさらに陽極板５方向に泳動しようとするが、希釈室１０との境界の陽イオン交換膜Ｃに阻止される。このように水酸イオン室１３のＮａイオンは次の透析単位を構成する第２濃縮室１２に移動し、ＯＨイオンは第１濃縮室１１に移動する。
上記のようにして、希釈室１０に導入されたＮＨ4 イオンとＳＯ4 イオンは希釈され、配管ｆから系外に排出されるか再循環される。また、水酸イオン室１３に導入されたＮａＯＨは希釈されて配管ｈから流出し、新たなＮａＯＨ液を補給され再循環される。
【００１１】
第１濃縮室１１には希釈室１０から移動したＮＨ4 イオンと水酸イオン室１３から移動したＯＨイオンが存在するが、ＮＨ4 イオンとＯＨイオンは、アンモニア（ＮＨ3 ）との間で可逆的反応をする。図３は室内のｐＨを変化したときのＮＨ3 とＮＨ4 イオンとの存在割合を、温度をパラメータとして測定した結果である。
図３から判るように、室内のｐＨが高くなるほどその反応はＮＨ3 側に移行するが、少なくともｐＨを１２以上のアルカリ側に維持することにより、温度が変化しても反応はほぼ１００％ＮＨ3 側に移行した状態で平衡する。第１濃縮室１１内は配管ｋから導入したＮａＯＨ液により、そのような高ｐＨ、少なくともその温度において反応がほぼ１００％ＮＨ3 側に平衡する条件の高いｐＨに維持され、それによって第１濃縮室１１内に移動したＮＨ4 イオンは、気体アンモニア（ＮＨ3 ）として分離され配管ｉから効率良く取り出し回収できる。一方、第１濃縮室１１からはＮａＯＨを含む液が配管ｍにより流出するが、これは再循環される。
【００１２】
【実験例】
次に図１のフローシートのように構成された本発明の実施例を示す。
配管ａから０．３リットル／時のアンモニア性窒素を含有する復水脱塩再生水をｐＨ調整槽１に供給し、そこで硫酸を添加してｐＨを３に調整した。ｐＨ調整された再生水は次に中空糸膜フイルタ３でＳＳとして０．２ｐｐｍまで固形粒子除去した後、電気透析装置４に導入して電気透析処理をした。電気透析装置４の有効膜面積は１．７２ｄｍ／対、組込膜対数は１である。
水酸イオン室１３には濃度ｐＨ１２のＮａＯＨ液を０．３リットル／時流し、さらに第１濃縮室に濃度ｐＨ１２のＮａＯＨ液を０．３リットル／時流してそのｐＨを１２に維持した。その結果、配管ｉから気体としてのアンモニアが１．３リットル／時回収された。一方、配管ｍからはアンモニウムイオンを実質的に含まないＮａＯＨ液が流出した。
【００１３】
【発明の効果】
本発明の方法によれば、複雑な設備や大きな敷地面積を必要とせず、多大のエネルギーの消費をすることなく、アンモニア性窒素を効率良く除去することができる。さらに本発明の方法によれば、アンモニアを気体として容易に分離回収することができるので環境の問題を生じることがなく、しかも回収したアンモニアは資源として有効活用できる。
【図面の簡単な説明】
【図１】本発明のアンモニア性窒素の除去方法を実施するための処理フローシート。
【図２】本発明の方法において使用する電気透析装置の原理を説明する模式的な図。
【図３】アンモニウムイオンとアンモニアの平衡条件を示す図。
【符号の説明】
１ ｐＨ調整槽
２ ポンプ
３ 中空糸膜フイルタ
４ 電気透析装置
５ 陽極板
６ 陰極板
１０ 希釈室
１１ 第１濃縮室
１２ 第２濃縮室
１３ 水酸イオン室
Ａ 陰イオン交換膜
Ｃ 陽イオン交換膜[0001]
[Industrial application fields]
The present invention relates to a method for removing ammonia nitrogen present in a liquid such as condensate demineralized reclaimed water in a thermal power plant as ammonia gas.
[0002]
[Prior art]
For example, condensate in a thermal power plant is usually desalted with an ion exchange resin to form condensate demineralized reclaimed water, and the reclaimed water generally contains ammonia nitrogen in an amount exceeding environmental standards. Conventionally, an ammonia diffusion (stripping) method has been frequently used as a method of reducing ammonia nitrogen in such condensate demineralized reclaimed water to be below the environmental standard.
[0003]
[Problems to be solved by the invention]
However, this stripping method requires a complicated facility and a large site area, and also has a problem of consuming a great deal of energy. Moreover, since it is not environmentally preferable to release ammonia together with evaporated water into the atmosphere, in order to avoid this, further post-treatment facilities are required. Even if such facilities are provided, ammonia as a resource is also required. It is not easy to recover.
Accordingly, an object of the present invention is to provide a method for removing ammoniacal nitrogen for solving such problems.
[0004]
[Means for Solving the Problems]
The present invention relates to electrodialysis in which an ammonium salt is precipitated and removed by adding an acid to a liquid containing ammoniacal nitrogen, and the resulting liquid containing ammonium ions is alternately arranged with a cation exchange membrane and an anion exchange membrane. This is a method of removing ammoniacal nitrogen treated by an apparatus.
As a dialysis unit of the electrodialysis apparatus, a dilution chamber for introducing a solution containing ammonium ions, a first concentration chamber adjacent to the cation exchange membrane side of the dilution chamber, and an anion exchange membrane side of the dilution chamber are adjacent to each other. The second concentration chamber includes a hydroxide ion chamber in which a hydroxide ion-containing liquid flows adjacent to the anion exchange membrane side of the first concentration chamber. Further, the pH of the first concentrating chamber is maintained at an alkalinity so as to be an equilibrium condition for generating ammonia from ammonium ions moving from the dilution chamber and hydroxide ions moving from the hydroxide ion chamber. And the produced | generated ammonia is taken out from a 1st concentration chamber as gas, It is characterized by the above-mentioned.
[0005]
【Example】
Next, the ammonia nitrogen removing method of the present invention will be described in more detail.
FIG. 1 is an example of a processing flow sheet for carrying out the ammonia nitrogen removing method of the present invention, wherein 1 is a pH adjusting tank, 2 is a pump, 3 is a hollow fiber membrane filter, and 4 is an electrodialysis apparatus.
The liquid a containing ammonia nitrogen is mixed with the acid b added in the pH adjusting tank 1, and the pH is adjusted to 4 or less, preferably about 2 to 4, whereby the ammonia nitrogen precipitates as an ammonium salt. It is removed from the pipe c. The acid to be added is preferably a mineral acid such as hydrochloric acid or sulfuric acid. Ammonium ions (NH 4 ions) that do not precipitate and inorganic ions such as sulfuric acid (SO 4 ions) are left in the solution when sulfuric acid is used as the acid.
The liquid containing ammonium ions from the pH adjusting tank 1 is sent by the pump 2 through the pipe d to the hollow fiber membrane filter 3 to remove fine solid particles. By removing the solid particles, the effective treatment time of the dialysis membrane in the electrodialysis apparatus can be greatly extended.
[0006]
The reclaimed water from which the solid particles have been removed is introduced into the dilution chamber of the electrodialyzer 4 through the pipe e, where a liquid in which a certain amount of ammonia ions and other inorganic ions have been reduced by the electrodialysis treatment is discharged through the pipe f. And reused or released out of the system.
As will be described later, the electrodialysis apparatus 4 includes a large number of cation exchange membranes and anion exchange membranes alternately arranged, and the dilution chamber, the first concentration chamber, the second concentration chamber, and the hydroxide ion chamber partitioned by them are dialysis units. It has become. Then, a liquid containing sodium hydroxide (NaOH) as a hydroxide ion supply liquid is introduced into the hydroxide ion chamber through the pipe g and flows out from the pipe h. Further, a liquid containing an alkaline agent, for example, sodium hydroxide (NaOH) liquid is introduced into the first concentration chamber through the pipe k in order to maintain the room at a high pH, and the NaOH liquid flows out from the first concentration chamber through the pipe m. To do. Also, ammonia as a gas rises in the first concentration chamber and is taken out from the pipe i. Further, a liquid containing inorganic ions such as SO 4 ions and Na ions concentrated in the second concentration chamber flows out from the pipe j.
[0007]
Next, FIG. 2 is a diagram schematically showing the electrodialysis apparatus 4 used in the present invention. For example, a large number of cation exchange membranes C and anion exchange membranes A are alternately arranged between an anode plate 5 platinum-plated on a titanium plate and a cathode plate 6 made of a stainless steel plate. As the anion exchange membrane A, for example, a membrane of a styrene / divinylbenzene copolymer system containing a quaternary ammonium salt as an ion exchange group of 1.5 to 3.0 (meq / g dry resin) is used. As C, for example, a styrene / divinylbenzene copolymer film containing 1.5 to 3.0 (meq / g dry resin) of a sulfonic acid group as an ion exchange group is used. An anolyte flows between the anode plate 5 and the anion exchange membrane A adjacent thereto, and a catholyte flows between the cathode plate 6 and the cation exchange membrane C adjacent thereto.
[0008]
The logarithm of the ion exchange membrane varies depending on the concentration of ammonia ions contained in the liquid, the desired treatment amount, etc., but generally about 200 to 900 pairs are used. A dilution chamber 10 for introducing a liquid containing ammonium ions is disposed between the pair of cation exchange membrane C and anion exchange membrane A, and the first concentration chamber is adjacent to the cation exchange membrane C side of the dilution chamber 10. 11. The water in which the second concentration chamber 12 is disposed adjacent to the anion exchange membrane A side of the dilution chamber 10 and the hydroxide ion-containing liquid flows adjacent to the anion exchange membrane A side of the first concentration chamber 11. An acid ion chamber 13 is disposed. The dilution chamber 10, the first concentration chamber 11, the second concentration chamber 12, and the hydroxide ion chamber 13 constitute a dialysis unit U, and a large number of such dialysis units are arranged between the anode plate 5 and the cathode plate 6. Has been.
[0009]
As described above, when sulfuric acid is used as the acid, a solution containing ammonium ions (NH 4 ions) and sulfate ions (SO 4 ions) is introduced into the dilution chamber 10 through the pipe e, where these ions are negative-anode. Electrophoresis is performed by an electric field formed between the plates. NH 4 ions (cations) migrate in the direction of the cathode plate 6, pass through the cation exchange membrane C, and move to the first concentration chamber 11. NH 4 ions in the first concentration chamber 11 try to migrate further toward the cathode plate 6, but are blocked by the anion exchange membrane A at the boundary with the hydroxide ion chamber 13.
On the other hand, SO 4 ions (anions) migrate in the direction of the anode plate 5, pass through the anion exchange membrane A, and move to the second concentration chamber 12. The SO 4 ions in the second concentrating chamber 12 try to migrate further in the direction of the anode plate 5, but are blocked by the cation exchange membrane C at the boundary with the hydroxide ion chamber 13 constituting the next dialysis unit and concentrated solution. Remain in. Thus, NH 4 ions in the dilution chamber 10 move to the first concentration chamber 11, and SO 4 ions move to the second concentration chamber 12.
[0010]
The liquid containing sodium hydroxide introduced into the hydroxide ion chamber 13 in the center of the figure by the pipe g is ionized into sodium ions (Na ions) that are cations and hydroxide ions (OH ions) that are anions. . Na ions migrate in the direction of the cathode plate 6 by the electric field formed between the negative and positive electrode plates, pass through the cation exchange membrane C, and move to the second concentration chamber 12 constituting the next dialysis unit. Na ions in the second concentration chamber 12 try to migrate further toward the cathode plate 6 but are blocked by the anion exchange membrane A.
On the other hand, OH ions migrate in the direction of the anode plate 5, pass through the anion exchange membrane A, and move to the first concentration chamber 11. The OH ions in the first concentration chamber 11 try to migrate further in the direction of the anode plate 5, but are blocked by the cation exchange membrane C at the boundary with the dilution chamber 10. Thus, Na ions in the hydroxide ion chamber 13 move to the second concentration chamber 12 constituting the next dialysis unit, and OH ions move to the first concentration chamber 11.
As described above, NH 4 ions and SO 4 ions introduced into the dilution chamber 10 are diluted and discharged out of the system from the pipe f or recirculated. Further, the NaOH introduced into the hydroxide ion chamber 13 is diluted and flows out from the pipe h, is replenished with a new NaOH solution, and is recirculated.
[0011]
In the first concentration chamber 11, there are NH 4 ions moved from the dilution chamber 10 and OH ions moved from the hydroxide ion chamber 13. The NH 4 ions and OH ions are reversible between ammonia (NH 3 ). To react. FIG. 3 shows the results of measuring the abundance ratio of NH 3 and NH 4 ions when the indoor pH is changed using temperature as a parameter.
As can be seen from FIG. 3, the reaction shifts to the NH 3 side as the indoor pH increases. However, the reaction is almost 100% NH even if the temperature changes by maintaining at least the pH of 12 or higher. Equilibrate in the state shifted to the 3 side. The inside of the first concentration chamber 11 is maintained at such a high pH, at least at such a temperature, by a NaOH solution introduced from the pipe k at a high pH under which the reaction equilibrates to the nearly 100% NH 3 side. The NH 4 ions moved into the chamber 11 are separated as gaseous ammonia (NH 3 ) and can be efficiently taken out and recovered from the pipe i. On the other hand, a liquid containing NaOH flows out from the first concentration chamber 11 through the pipe m, but this is recirculated.
[0012]
[Experimental example]
Next, the Example of this invention comprised like the flow sheet of FIG. 1 is shown.
Condensate demineralized regenerated water containing ammonia nitrogen at 0.3 liter / hour was supplied to the pH adjustment tank 1 from the pipe a, and sulfuric acid was added thereto to adjust the pH to 3. The pH-adjusted reclaimed water was then subjected to solid dial removal to 0.2 ppm as SS with the hollow fiber membrane filter 3 and then introduced into the electrodialysis apparatus 4 for electrodialysis treatment. The effective membrane area of the electrodialysis apparatus 4 is 1.72 dm / pair, and the number of built-in membrane pairs is 1.
A NaOH solution having a concentration of pH 12 was flowed into the hydroxide ion chamber 13 at 0.3 liter / hour, and an NaOH solution having a concentration of pH 12 was flowed into the first concentration chamber at 0.3 liter / hour to maintain the pH at 12. As a result, 1.3 liter / hour of ammonia as a gas was recovered from the pipe i. On the other hand, an NaOH solution substantially free of ammonium ions flowed out from the pipe m.
[0013]
【The invention's effect】
According to the method of the present invention, ammonia nitrogen can be efficiently removed without requiring complicated facilities or a large site area and without consuming a great deal of energy. Furthermore, according to the method of the present invention, ammonia can be easily separated and recovered as a gas, so that environmental problems do not occur, and the recovered ammonia can be effectively used as a resource.
[Brief description of the drawings]
FIG. 1 is a process flow sheet for carrying out the method for removing ammoniacal nitrogen of the present invention.
FIG. 2 is a schematic diagram illustrating the principle of an electrodialysis apparatus used in the method of the present invention.
FIG. 3 is a view showing an equilibrium condition between ammonium ions and ammonia.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 pH adjustment tank 2 Pump 3 Hollow fiber membrane filter 4 Electrodialyzer 5 Anode plate 6 Cathode plate 10 Dilution chamber 11 First concentration chamber 12 Second concentration chamber 13 Hydroxide ion chamber A Anion exchange membrane C Cation exchange membrane

Claims (2)

アンモニア性窒素を含有する液に酸を添加してアンモニウム塩を沈澱除去し、アンモニウムイオンを含む液を陽イオン交換膜Ｃと陰イオン交換膜Ａが交互に配置された電気透析装置４で処理するアンモニア性窒素の除去方法であって、電気透析装置４の透析単位Ｕとして、アンモニウムイオンを含む液を導入する希釈室１０と、該希釈室１０の陽イオン交換膜Ｃ側に隣接する第１濃縮室１１と、該希釈室１０の陰イオン交換膜Ａ側に隣接する第２濃縮室１２と、前記第１濃縮室１１の陰イオン交換膜Ａ側に隣接して水酸イオン含有液が流れる水酸イオン室１３を含み、前記第１濃縮室１１のｐＨを前記希釈室１０より移動するアンモニウムイオンと前記水酸イオン室１３から移動する水酸イオンからアンモニアを生成する平衡条件となるようなアルカリ性に維持し、それによって生成したアンモニアを気体として該第１濃縮室１１から取り出すことを特徴とするアンモニア性窒素の除去方法。An acid is added to a liquid containing ammonia nitrogen to precipitate and remove ammonium salts, and a liquid containing ammonium ions is processed by an electrodialysis apparatus 4 in which cation exchange membranes C and anion exchange membranes A are alternately arranged. A method for removing ammonia nitrogen, which is a dialysis unit U of the electrodialyzer 4, a dilution chamber 10 for introducing a liquid containing ammonium ions, and a first concentration adjacent to the cation exchange membrane C side of the dilution chamber 10. Chamber 11, the second concentration chamber 12 adjacent to the anion exchange membrane A side of the dilution chamber 10, and the water in which the hydroxide ion-containing liquid flows adjacent to the anion exchange membrane A side of the first concentration chamber 11 An acid ion chamber 13 is included, and the pH of the first concentrating chamber 11 becomes an equilibrium condition for generating ammonia from ammonium ions moving from the dilution chamber 10 and hydroxide ions moving from the hydroxide ion chamber 13. Maintaining the alkaline method of removing ammonia nitrogen, characterized in that retrieving the ammonia formed from the first concentrating compartment 11 as a gas thereby. 第１濃縮室１１のｐＨを１２以上の高アルカリ性に維持する請求項１のアンモニア性窒素の除去方法。The method for removing ammoniacal nitrogen according to claim 1, wherein the pH of the first concentration chamber 11 is maintained at a high alkalinity of 12 or more.
JP06184595A 1995-02-24 1995-02-24 Ammonia nitrogen removal method Expired - Fee Related JP3637458B2 (en)

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Cited By (2)

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US11502323B1 (en) 2022-05-09 2022-11-15 Rahul S Nana Reverse electrodialysis cell and methods of use thereof
US11502322B1 (en) 2022-05-09 2022-11-15 Rahul S Nana Reverse electrodialysis cell with heat pump

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JPH10167720A (en) * 1996-11-29 1998-06-23 Toshiba Eng & Constr Co Ltd Treatment of ammonia-containing solution
JP6917369B2 (en) * 2015-10-30 2021-08-11 中国石油化工股▲ふん▼有限公司 Wastewater treatment method and treatment system, and molecular sieve preparation method and production system

Cited By (5)

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Publication number Priority date Publication date Assignee Title
US11502323B1 (en) 2022-05-09 2022-11-15 Rahul S Nana Reverse electrodialysis cell and methods of use thereof
US11502322B1 (en) 2022-05-09 2022-11-15 Rahul S Nana Reverse electrodialysis cell with heat pump
US11563229B1 (en) 2022-05-09 2023-01-24 Rahul S Nana Reverse electrodialysis cell with heat pump
US11611099B1 (en) 2022-05-09 2023-03-21 Rahul S Nana Reverse electrodialysis cell and methods of use thereof
US11699803B1 (en) 2022-05-09 2023-07-11 Rahul S Nana Reverse electrodialysis cell with heat pump

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