JP2000301171A - Method for treating wastewater containing hydrazine - Google Patents
Method for treating wastewater containing hydrazineInfo
- Publication number
- JP2000301171A JP2000301171A JP11263999A JP11263999A JP2000301171A JP 2000301171 A JP2000301171 A JP 2000301171A JP 11263999 A JP11263999 A JP 11263999A JP 11263999 A JP11263999 A JP 11263999A JP 2000301171 A JP2000301171 A JP 2000301171A
- Authority
- JP
- Japan
- Prior art keywords
- hydrazine
- percarbonate
- hydrogen peroxide
- containing wastewater
- reaction catalyst
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Removal Of Specific Substances (AREA)
- Treatment Of Water By Oxidation Or Reduction (AREA)
- Catalysts (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ヒドラジン含有排
水の処理方法の改良に関し、さらに詳しくは、ボイラな
どから排出されるヒドラジン含有排水中のヒドラジン
を、効率よく酸化分解処理して除去する方法に関するも
のである。The present invention relates to an improvement in a method for treating hydrazine-containing wastewater, and more particularly, to a method for efficiently removing hydrazine in hydrazine-containing wastewater discharged from a boiler by oxidative decomposition. Things.
【０００２】[0002]
【従来の技術】従来、発電所などにおいて、ボイラの定
期点検や保守などの運転休止時に、薬品洗浄などを行っ
たのち、休止中のボイラ内部の腐食を防止するために、
通常ヒドラジンを添加した純水で満水とする処置がとら
れ、そして運転再開時には、ヒドラジンを高濃度（通常
数百mg／リットル、具体的には１００〜３００mg／リッ
トルの場合が多い）で含む排水として排出される。この
ように高濃度でヒドラジンを含有する排水をそのまま河
川や海域に放流すると環境汚染をもたらすので、通常ヒ
ドラジンを除去処理したのち、河川や海域に放流してい
る。ヒドラジン含有排水の処理方法としては、従来、酸
化剤として塩素ガスや次亜塩素酸ナトリウムなどを用
い、酸化分解処理する方法が行われている。しかしなが
ら、この方法でヒドラジンを分解するには、塩素ガスや
次亜塩素酸ナトリウムを、ヒドラジンを分解するのに必
要な量（当量）以上に添加する必要があり、余剰の残留
塩素が残存することとなり、したがって、この残留塩素
を処理するための付加的処理が必要となる。このような
欠点を解消するために、酸化剤として過酸化水素を添加
する方法が試みられている。しかしながら、この方法に
おいては、ヒドラジンの分解速度が極めて遅いので、反
応時間を長くしたり、温度を高めたりすることが必要で
あり、さらに大過剰の過酸化水素を使用することも必要
であった。過酸化水素によるヒドラジンの分解速度を高
めるために、例えばヒドラジン含有排水に、過酸化水素
と銅化合物を添加し、水酸化ナトリウムなどのアルカリ
剤によってpHを調整しながら、反応させる方法が提案さ
れている（特開平９−２３４４７３号公報）。しかしな
がら、この方法においては、ヒドラジンの分解の最適pH
は１０〜１１.５の範囲であり、このpHを維持するため
には、アルカリ剤の添加量を制御する必要があり、装置
が複雑化するのを免れない。また、水酸化ナトリウムは
強アルカリであるため、過不足によるpH変動が大きくな
るという問題もある。なお、前記次亜塩素酸ナトリウム
は、海洋汚染防止法（第１有害液体物質）、危険則（危
険物：腐食性物質）、労働安全衛生法（危険物：酸化性
の物）に該当する。一方、過酸化水素は、毒・劇物取締
法（劇物）、消防法（第２条危険物第６類過酸化水
素）、労働安全衛生法（危険物：酸化性の物）に該当す
る。したがって、次亜塩素酸ナトリウムや過酸化水素を
用いる方法においては、取り扱い性の問題及び安全性の
改良が必要であった。他方、ヒドラジン含有排水に、過
酸化水素発生源として、過ホウ酸ナトリウムを添加する
方法（特開昭５７−１９０８７号公報）が提案されてい
るが、この方法においては、処理水にホウ素が残留する
という問題が生じる。また、ヒドラジンを含む写真廃液
に、過炭酸塩を添加する方法（特公平５−５４９３１号
公報）が開示されている。この方法においては、廃液自
体に銅、ニッケルなどの化合物が含まれる場合もある
が、反応触媒としてこれらを添加することは記載されて
いない。2. Description of the Related Art Conventionally, in a power plant or the like, after a chemical cleaning or the like is performed at the time of a shutdown of a boiler for periodic inspection and maintenance, etc., in order to prevent corrosion inside the boiler during a shutdown.
Usually, a treatment is taken to fill the water with pure water to which hydrazine is added, and at the time of restarting operation, wastewater containing hydrazine at a high concentration (usually several hundred mg / liter, specifically, often 100 to 300 mg / liter). Is discharged as Discharging wastewater containing hydrazine at such a high concentration into rivers and seas as it is causes environmental pollution. Therefore, hydrazine is usually removed and then discharged to rivers and seas. As a method for treating hydrazine-containing wastewater, conventionally, a method of performing oxidative decomposition treatment using chlorine gas, sodium hypochlorite, or the like as an oxidizing agent has been used. However, in order to decompose hydrazine by this method, it is necessary to add chlorine gas or sodium hypochlorite in an amount (equivalent) necessary to decompose hydrazine, and excess residual chlorine remains. Therefore, an additional treatment for treating this residual chlorine is required. In order to solve such a defect, a method of adding hydrogen peroxide as an oxidizing agent has been attempted. However, in this method, since the decomposition rate of hydrazine is extremely slow, it is necessary to lengthen the reaction time, increase the temperature, and also use a large excess of hydrogen peroxide. . In order to increase the decomposition rate of hydrazine by hydrogen peroxide, for example, a method of adding hydrogen peroxide and a copper compound to hydrazine-containing wastewater and adjusting the pH with an alkaline agent such as sodium hydroxide, and reacting the same has been proposed. (JP-A-9-234473). However, in this method, the optimal pH for hydrazine degradation is
Is in the range of 10 to 11.5. In order to maintain this pH, it is necessary to control the amount of the alkali agent added, and the apparatus is inevitably complicated. In addition, since sodium hydroxide is a strong alkali, there is also a problem that fluctuation in pH due to excess or deficiency increases. The sodium hypochlorite falls under the Marine Pollution Prevention Law (first hazardous liquid substance), the danger rule (dangerous substances: corrosive substances), and the Industrial Safety and Health Law (dangerous substances: oxidizing substances). On the other hand, hydrogen peroxide falls under the Poisonous and Deleterious Substances Control Law (Dangerous Goods), the Fire Service Law (Article 2, Dangerous Goods, Class 6 Hydrogen Peroxide), and the Industrial Safety and Health Law (Dangerous Goods: Oxidizing Substances). . Therefore, in the method using sodium hypochlorite and hydrogen peroxide, it is necessary to improve handling and safety. On the other hand, a method has been proposed in which sodium perborate is added to hydrazine-containing wastewater as a source of hydrogen peroxide (Japanese Patent Application Laid-Open No. 57-19087). However, in this method, boron remains in treated water. Problem arises. A method of adding a percarbonate to a photographic waste solution containing hydrazine (Japanese Patent Publication No. 5-54931) is disclosed. In this method, compounds such as copper and nickel may be contained in the waste liquid itself, but it is not described to add these as a reaction catalyst.
【０００３】[0003]
【発明が解決しようとする課題】本発明は、このような
事情のもとで、ボイラなどから排出されるヒドラジン含
有排水中のヒドラジンを、酸化分解処理により効率よく
除去することができ、しかも取り扱い性が容易で安全性
の高い工業的に有利なヒドラジン含有排水の処理方法を
提供することを目的としてなされたものである。SUMMARY OF THE INVENTION Under such circumstances, the present invention can efficiently remove hydrazine in hydrazine-containing wastewater discharged from a boiler or the like by oxidative decomposition treatment. It is an object of the present invention to provide an industrially advantageous method for treating hydrazine-containing wastewater that is easy to operate and safe.
【０００４】[0004]
【課題を解決するための手段】本発明者は、前記目的を
達成するために鋭意研究を重ねた結果、ヒドラジン含有
排水に、酸化剤である過炭酸塩とある種の金属化合物か
らなる反応触媒とを共存させ、ヒドラジンを酸化分解す
ることにより、その目的を達成しうることを見出し、こ
の知見に基づいて本発明を完成するに至った。すなわ
ち、本発明は、（１）ヒドラジン含有排水に、（Ａ）過
炭酸塩と、（Ｂ）銅、マンガン、コバルト及びニッケル
化合物の中から選ばれた少なくとも１種の反応触媒を共
存させ、ヒドラジンを酸化分解することを特徴とするヒ
ドラジン含有排水の処理方法、（２）（Ａ）成分の過炭
酸塩を、排水中に含有するヒドラジンの０.５〜３倍当
量とする第(１)項記載のヒドラジン含有排水の処理方
法、及び（３）（Ｂ）成分を、その金属濃度が０.０１
〜２mg／リットルになるように共存させる第(１)又は
(２)項記載のヒドラジン含有排水の処理方法、を提供す
るものである。また、本発明の好ましい態様は、（４）
（Ａ）成分の過炭酸塩が過炭酸ナトリウムである第(１)
〜(３)項記載のヒドラジン含有排水の処理方法、及び
（５）空気曝気処理を併用して、ヒドラジンを酸化分解
する第(１)〜(４)項記載のヒドラジン含有排水の処理方
法、である。Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have found that a reaction catalyst comprising a percarbonate as an oxidizing agent and a certain metal compound is added to hydrazine-containing wastewater. And coexistence thereof, and found that the object can be achieved by oxidative decomposition of hydrazine, and completed the present invention based on this finding. That is, the present invention provides (1) a hydrazine-containing wastewater in which (A) a percarbonate and (B) at least one reaction catalyst selected from copper, manganese, cobalt and nickel compounds coexist; (2) A method for treating a hydrazine-containing wastewater, wherein the percarbonate of the component (A) is 0.5 to 3 equivalents of hydrazine contained in the wastewater. The method for treating hydrazine-containing wastewater as described in (3) and (3), wherein the component (B) has a metal concentration of 0.01.
No. (1) or coexisting to be ~ 2 mg / l
(2) A method for treating hydrazine-containing wastewater according to the item (2). Further, a preferred embodiment of the present invention provides (4)
Component (A) wherein the percarbonate is sodium percarbonate
(3) The method for treating hydrazine-containing wastewater according to any one of (1) to (4), wherein the method for treating hydrazine-containing wastewater according to (1) to (4), wherein hydrazine is oxidatively decomposed using air aeration treatment in combination. is there.
【０００５】[0005]
【発明の実施の形態】本発明のヒドラジン含有排水の処
理方法においては、（Ａ）成分の酸化剤として、過炭酸
塩が用いられる。この過炭酸塩としては、水溶性のもの
であればよく、特に制限されず、例えば炭酸塩過酸化水
素化物(２Ｍ2ＣＯ3・３Ｈ2Ｏ2、Ｍは一価の金属原子、
以下同様)、ペルオキソ一炭酸塩（Ｍ2ＣＯ4）、ペルオ
キソ二炭酸塩（Ｍ2Ｃ2Ｏ6）などが挙げられるが、工業
的に入手が可能であり、かつ効果の点から炭酸ナトリウ
ム過酸化水素化物及び炭酸カリウム過酸化水素化物が好
ましい。この過炭酸塩は単独で用いてもよいし、２種以
上を組み合わせて用いてもよいが、経済性及び性能など
の面から、特に炭酸ナトリウム過酸化水素化物が好適で
ある。本発明方法において特に好適に用いられる炭酸塩
過酸化水素化物はpH緩衝能を有し、通常、ヒドラジン含
有排水中に、該ヒドラジンを分解するのに必要な量を添
加した場合、ヒドラジンの分解反応に適したpH、すなわ
ちpH１０〜１１.５程度になる。したがって、被処理ヒ
ドラジン含有排水が中性である場合には、通常pH調整は
必要でない。しかし、被処理ヒドラジン含有排水が酸性
であったり、pH１３以上の強アルカリ性であって、炭酸
塩過酸化水素化物を所定量添加した際に、pHが１０〜１
１.５の範囲を逸脱する場合には、pHが上記範囲内にな
るようにpH調整するのが望ましい。BEST MODE FOR CARRYING OUT THE INVENTION In the method for treating hydrazine-containing wastewater of the present invention, percarbonate is used as an oxidizing agent for the component (A). The percarbonate is not particularly limited as long as it is water-soluble. For example, carbonate hydrogen peroxide (2M 2 CO 3 .3H 2 O 2 , M is a monovalent metal atom,
The same applies hereinafter), peroxomonocarbonate (M 2 CO 4 ), peroxodicarbonate (M 2 C 2 O 6 ) and the like. Hydrogen oxides and potassium hydrogen peroxide are preferred. This percarbonate may be used alone or in combination of two or more. From the viewpoints of economy, performance, and the like, sodium hydrogencarbonate peroxide is particularly preferred. The carbonate hydrogen peroxide that is particularly preferably used in the method of the present invention has a pH buffering capacity, and usually, when hydrazine-containing wastewater is added in an amount necessary to decompose the hydrazine, a hydrazine decomposition reaction is performed. PH, that is, about pH 10 to 11.5. Therefore, when the hydrazine-containing wastewater to be treated is neutral, it is not usually necessary to adjust the pH. However, the hydrazine-containing wastewater to be treated is acidic or strongly alkaline having a pH of 13 or more, and when a predetermined amount of carbonate hydrogen peroxide is added, the pH becomes 10 to 1
When the value is outside the range of 1.5, it is desirable to adjust the pH so that the pH is within the above range.
【０００６】本発明方法において、過炭酸塩を用いてヒ
ドラジンを酸化分解する際の反応式を、過炭酸塩が炭酸
ナトリウム過酸化水素化物である場合の例を挙げて示す
と、下記のとおりである。なお、炭酸ナトリウム過酸化
水素化物は、２０℃の水１００ｇに対し、１４ｇの溶解
性を有している。また、水溶液のpHはアルカリ性を示
す。 Ｎ2Ｈ4＋２／３（２Ｎａ2ＣＯ3・３Ｈ2Ｏ2） →Ｎ2＋４Ｈ2Ｏ＋４／３Ｎａ2ＣＯ3 …［１］ 本発明方法においては、該過炭酸塩の添加量は、例えば
反応式［１］で示されるようなヒドラジンの酸化分解に
必要な量の０.５〜３倍当量の範囲で選ぶのが有利であ
る。この量が０.５倍当量未満ではヒドラジンの分解が
不十分となるおそれがあるし、３倍当量を超えるとその
量の割にはヒドラジンの酸化分解効果の向上は認められ
ず、むしろ経済的に不利となる。ヒドラジンの酸化分解
効果及び経済性などを考慮すると、過炭酸塩の好ましい
添加量は１〜２倍当量の範囲である。なお、過炭酸塩の
添加量が１倍当量未満の場合、空気曝気との併用が有効
である。この場合、過炭酸塩と共に空気中の酸素によ
り、ヒドラジンが酸化される。本発明方法においては、
固体状の過炭酸塩を反応槽にサイロから直接添加し、溶
解してもよいし、別途溶解槽を設け、水又は少量の被処
理水で過炭酸塩を溶解し、これを反応槽に添加してもよ
い。過炭酸塩の溶解方法については特に制限はなく、例
えば粒状、タブレット状に成形した過炭酸塩を反応槽に
投入して、徐々に溶解させてもよいし、顆粒、粉末、成
形品の過炭酸塩を透水性の容器（かご、袋）に入れて、
反応槽に浸漬するか、被処理排水をこの容器に通して反
応槽に導入してもよい。In the method of the present invention, the reaction formula for oxidatively decomposing hydrazine using a percarbonate is shown as follows, using an example in which the percarbonate is sodium hydrogencarbonate peroxide. is there. The sodium hydrogen peroxide has a solubility of 14 g in 100 g of water at 20 ° C. Further, the pH of the aqueous solution indicates alkaline. N 2 H 4 +2/3 (2Na 2 CO 3 .3H 2 O 2 ) → N 2 + 4H 2 O + 4 / 3Na 2 CO 3 [1] In the method of the present invention, the amount of the percarbonate added is, for example, It is advantageous to select from 0.5 to 3 equivalents of the amount required for oxidative decomposition of hydrazine as shown by the formula [1]. If this amount is less than 0.5 equivalents, the decomposition of hydrazine may be insufficient. If it exceeds 3 equivalents, no improvement in the oxidative decomposition effect of hydrazine is recognized for the amount, and the economical efficiency is rather high. Disadvantaged. In consideration of the oxidative decomposition effect of hydrazine, economic efficiency, and the like, the preferable addition amount of percarbonate is in the range of 1 to 2 equivalents. When the amount of percarbonate added is less than 1 equivalent, the combined use with air aeration is effective. In this case, hydrazine is oxidized by oxygen in the air together with the percarbonate. In the method of the present invention,
Solid percarbonate may be directly added to the reaction tank from a silo and dissolved, or a separate dissolution tank may be provided to dissolve the percarbonate in water or a small amount of water to be treated and then added to the reaction tank. May be. There is no particular limitation on the method of dissolving percarbonate.For example, percarbonate formed into granules or tablets may be put into a reaction vessel and gradually dissolved, or percarbonate of granules, powders, and molded products may be dissolved. Put the salt in a permeable container (basket, bag)
The effluent to be treated may be introduced into the reaction tank by immersing it in the reaction tank or passing the wastewater to be treated through this container.
【０００７】本発明方法においては、（Ｂ）成分の反応
触媒として、銅化合物、コバルト化合物、マンガン化合
物及びニッケル化合物の中から選ばれた１種又は２種以
上が用いられる。上記金属化合物としては、例えば硫酸
塩や塩化物が好適である。これらの化合物は、金属濃度
として、０.０１〜２mg／リットルの範囲になるように
過炭酸塩と共存させるのが好ましい。この金属濃度が
０.０１mg／リットル未満では反応速度が遅すぎて実用
的でないし、２mg／リットルを超えると、後段に凝集沈
殿処理などの工程を付加する必要が生じ、経済的に不利
となり、好ましくない。反応速度及び経済性などを考慮
すると、この反応触媒のより好ましい量は、金属濃度と
して０.１〜１mg／リットルの範囲である。反応触媒で
ある前記金属化合物を過炭酸塩と共存させる形式として
は特に制限はないが、過炭酸塩と混合して反応槽に添加
する方法、あるいは該金属化合物と過炭酸塩とを、別々
に反応槽に添加する方法が、装置が簡素化され好まし
い。本発明においては、前記反応触媒の金属化合物を適
当な担体に担持して固定床又は流動床とし、これに過炭
酸塩を添加したヒドラジン含有被処理水を通水して、ヒ
ドラジンの酸化分解処理を行うことができる。この際、
担体としては、多孔質のもの、例えばチタニア、アルミ
ナ、シリカ、シリカ−アルミナ、ジルコニア、ゼオライ
トなどの金属酸化物や金属複合酸化物、さらには活性炭
などを用いることができる。特に、担体に金属を担持し
たのち、次亜塩素酸塩などにより、金属を過酸化物とし
たものが、触媒活性が高く好ましい。In the method of the present invention, one or more selected from a copper compound, a cobalt compound, a manganese compound and a nickel compound are used as the reaction catalyst of the component (B). As the metal compound, for example, sulfates and chlorides are suitable. It is preferable that these compounds coexist with percarbonate so that the metal concentration is in the range of 0.01 to 2 mg / liter. If the metal concentration is less than 0.01 mg / liter, the reaction rate is too slow to be practical, and if it exceeds 2 mg / liter, it becomes necessary to add a step such as coagulation and sedimentation treatment at a later stage, which is economically disadvantageous. Not preferred. Considering the reaction rate and economy, a more preferable amount of the reaction catalyst is in the range of 0.1 to 1 mg / liter as the metal concentration. There is no particular limitation on the form in which the metal compound serving as the reaction catalyst coexists with the percarbonate.However, a method of mixing with the percarbonate and adding the mixture to the reaction vessel, or separately adding the metal compound and the percarbonate, The method of adding to the reaction tank is preferable because the apparatus is simplified. In the present invention, the metal compound of the reaction catalyst is supported on an appropriate carrier to form a fixed bed or a fluidized bed, and the hydrazine-containing water to which percarbonate has been added is passed through the hydrazine-treated water to oxidatively degrade hydrazine. It can be performed. On this occasion,
As the carrier, a porous material, for example, a metal oxide or metal composite oxide such as titania, alumina, silica, silica-alumina, zirconia, or zeolite, and activated carbon can be used. In particular, it is preferable to use a catalyst in which a metal is peroxide-deposited with hypochlorite after loading the metal on the carrier, because of its high catalytic activity.
【０００８】本発明方法においては、酸化分解処理は、
通常室温にて、０.５〜１０時間程度、好ましくは１〜
７時間程度行われるが、必要ならば、処理時間を短縮す
るなどの目的で、適当に加温して行うことができる。ま
た、前記したように、所望により、空気曝気を併用して
酸化分解処理を行う場合には、空気の曝気量は、槽容量
当たり、好ましくは１〜４Ｎｍ3／ｍ3・hr、より好まし
くは１〜２Ｎｍ3／ｍ3・hrの範囲で選ばれる。本発明方
法においては、このようにして排水中のヒドラジンを酸
化分解処理したのち、必要に応じ、反応触媒として用い
た金属化合物を分離除去し、さらに硫酸などの酸で中和
してから、系外へ排出してもよい。この際、該金属化合
物の分離除去方法としては特に制限はなく、反応槽中で
沈降分離させる方法、別途設けた沈殿槽中で凝集沈殿さ
せる方法、さらにはろ過法やイオン交換処理法などの方
法を用いることができる。本発明方法が適用されるヒド
ラジン含有排水としては、特に制限はなく、例えばボイ
ラの運転休止後、運転再開時に排出されるヒドラジンを
高濃度（通常数百mg／リットル、具体的には１００〜３
００mg／リットル程度）で含むブロー水、あるいはボイ
ラの定常運転時のブロー水（通常数十mg／リットル程度
のヒドラジンを含む）などを挙げることができる。In the method of the present invention, the oxidative decomposition treatment comprises:
Usually, at room temperature, about 0.5 to 10 hours, preferably 1 to 10 hours
It is carried out for about 7 hours, but if necessary, it can be carried out by appropriately heating for the purpose of shortening the processing time. Further, as described above, when performing oxidative decomposition treatment using air aeration as desired, the amount of air aeration is preferably 1 to 4 Nm 3 / m 3 · hr, more preferably, per tank capacity. It is selected in the range of 1-2 Nm 3 / m 3 · hr. In the method of the present invention, after the hydrazine in the waste water is subjected to the oxidative decomposition treatment in this manner, if necessary, the metal compound used as the reaction catalyst is separated and removed, and further neutralized with an acid such as sulfuric acid. It may be discharged outside. At this time, the method for separating and removing the metal compound is not particularly limited, and includes a method of sedimentation and separation in a reaction tank, a method of coagulation and sedimentation in a separately provided sedimentation tank, and a method such as a filtration method and an ion exchange treatment method. Can be used. There is no particular limitation on the hydrazine-containing wastewater to which the method of the present invention is applied. For example, after the boiler operation is stopped, the hydrazine discharged when the operation is restarted has a high concentration (usually several hundred mg / liter, specifically 100 to 3 mg / liter).
Blow water containing water (about 00 mg / liter) or blow water during normal operation of the boiler (usually containing about several tens mg / liter of hydrazine).
【０００９】[0009]
【実施例】次に、本発明を実施例により、さらに詳細に
説明するが、本発明は、これらの例によってなんら限定
されるものではない。 実施例１ ヒドラジン濃度３００mg／リットルの水溶液に、炭酸ナ
トリウム過酸化水素化物を２.０倍当量添加すると共
に、硫酸コバルトをコバルトが１.０mg／リットルにな
るように添加し、４時間機械撹拌したのち、ヒドラジン
濃度を測定し、ヒドラジン除去率を算出したところ、ヒ
ドラジン除去率は７３％であった。処理条件及び結果を
第１表に示す。 実施例２ 実施例１において、硫酸コバルトの代わりに硫酸銅を銅
が０.５mg／リットルになるように添加した以外は、実
施例１と同様に処理したところ、４時間後のヒドラジン
濃度は１mg／リットル未満であり、ヒドラジン除去率は
９９％を超える値であった。また、処理水のＣＯＤ（化
学的酸素要求量）は、１０mg／リットル未満であった。
処理条件及び結果を第１表に示す。 比較例１、２ ヒドラジン濃度３００mg／リットルの水溶液に炭酸ナト
リウム過酸化水素化物を２.０及び３.０倍当量添加し、
それぞれ４時間機械撹拌したのち、ヒドラジン濃度を測
定し、ヒドラジンの除去率を算出した。処理条件及び結
果を第１表に示す。 比較例３ ヒドラジン濃度３００mg／リットルの水溶液に、過酸化
水素を２.０倍当量添加すると共に、硫酸銅を銅が０.５
mg／リットルになるように添加し、４時間機械撹拌した
のち、ヒドラジン濃度を測定し、ヒドラジン除去率を算
出したところ、ヒドラジン除去率は５２％であった。処
理条件及び結果を第１表に示す。Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 To an aqueous solution having a hydrazine concentration of 300 mg / l, 2.0 equivalents of sodium hydrogen peroxide were added, and cobalt sulfate was added so that cobalt became 1.0 mg / l, followed by mechanical stirring for 4 hours. Thereafter, the hydrazine concentration was measured, and the hydrazine removal rate was calculated. As a result, the hydrazine removal rate was 73%. Table 1 shows the processing conditions and results. Example 2 The same treatment as in Example 1 was carried out except that copper sulfate was added in place of cobalt sulfate so that the copper concentration became 0.5 mg / L. The hydrazine concentration after 4 hours was 1 mg. / Liter, and the hydrazine removal rate was a value exceeding 99%. The COD (chemical oxygen demand) of the treated water was less than 10 mg / liter.
Table 1 shows the processing conditions and results. Comparative Examples 1 and 2 To a water solution having a hydrazine concentration of 300 mg / liter, 2.0 and 3.0 equivalents of sodium hydrogen peroxide were added.
After mechanical stirring for 4 hours, the hydrazine concentration was measured, and the hydrazine removal rate was calculated. Table 1 shows the processing conditions and results. Comparative Example 3 To an aqueous solution having a hydrazine concentration of 300 mg / liter, hydrogen peroxide was added in an amount of 2.0 equivalents, and copper sulfate was replaced with copper.
The mixture was mechanically stirred for 4 hours, and the hydrazine concentration was measured and the hydrazine removal rate was calculated. The hydrazine removal rate was 52%. Table 1 shows the processing conditions and results.
【００１０】[0010]
【表１】 [Table 1]
【００１１】以上の結果、比較例１、２ではヒドラジン
除去率が低いが、実施例１、２ではコバルト、銅の触媒
作用により高い除去率を示す。比較例３では、反応当初
は、ヒドラジンによりpHは１１程度（分解反応に好適な
pH）となる。しかし、過酸化水素によりヒドラジンが分
解されるにつれてpHが低下するので、反応速度は徐々に
低下すると考えられる。これに対し、実施例１、２で
は、過炭酸塩により、ヒドラジンの分解反応に適したpH
を維持するため、ヒドラジンの除去率が高い。As a result, in Comparative Examples 1 and 2, the hydrazine removal rate is low, but in Examples 1 and 2, the removal rate is high due to the catalytic action of cobalt and copper. In Comparative Example 3, at the beginning of the reaction, the pH was about 11 with hydrazine (suitable for a decomposition reaction).
pH). However, the reaction rate is thought to decrease gradually as the pH decreases as hydrazine is decomposed by hydrogen peroxide. On the other hand, in Examples 1 and 2, the pH suitable for the decomposition reaction of hydrazine was determined by the percarbonate.
, The hydrazine removal rate is high.
【００１２】[0012]
【発明の効果】本発明のヒドラジン含有排水の処理方法
は、下記の効果を奏する。 （１）酸化剤として過炭酸塩を用いるので、ホウ素など
の有害な物質が残留しない。 （２）酸化剤の過炭酸塩として好ましく用いられる炭酸
ナトリウム過酸化水素化物は、市販品として入手が容易
で、顆粒状であり、また法規制に該当するものがなく、
取り扱いが容易である。さらに水溶液はヒドラジン分解
に最適なアルカリ性を示し、新しく水酸化ナトリウムな
どのアルカリ剤を添加する必要がない。 （３）反応触媒として用いる金属化合物の量は、金属濃
度として、好ましくは２mg／リットル以下、より好まし
くは１mg／リットル以下であるので、新たに凝集沈殿除
去工程を設ける必要はない。 （４）反応時間を大幅に短縮することができ、作業効率
が大幅に向上する。本発明方法は、ボイラの運転休止
後、運転再開時に排出されるヒドラジンを高濃度で含む
ブロー水、あるいはボイラの定常運転時のブロー水など
に、好適に適用される。The method for treating hydrazine-containing wastewater of the present invention has the following effects. (1) Since percarbonate is used as an oxidizing agent, no harmful substances such as boron remain. (2) Sodium hydrogen peroxide, which is preferably used as a percarbonate of an oxidizing agent, is easily available as a commercial product, is in a granular form, and does not correspond to laws and regulations.
Easy to handle. Furthermore, the aqueous solution exhibits optimal alkalinity for hydrazine decomposition, and there is no need to newly add an alkaline agent such as sodium hydroxide. (3) Since the amount of the metal compound used as the reaction catalyst is preferably 2 mg / L or less, more preferably 1 mg / L or less as the metal concentration, it is not necessary to newly provide a coagulation / sedimentation removal step. (4) The reaction time can be greatly reduced, and the working efficiency is greatly improved. The method of the present invention is suitably applied to blow water containing a high concentration of hydrazine discharged at the time of restart of operation after boiler operation is stopped, or blow water at the time of steady operation of the boiler.
フロントページの続き Ｆターム(参考） 4D038 AA08 AB30 BA02 BA06 BB13 BB16 4D050 AA13 AB07 AB36 BB01 BB14 BC06 BD02 BD04 BD08 CA13 4G069 AA02 AA03 BB08A BB10A BB10B BC31A BC31B BC62A BC67A BC67B BC68A BD12A CA05 CA07 CA10 CA11 DA02Continued on the front page F term (reference) 4D038 AA08 AB30 BA02 BA06 BB13 BB16 4D050 AA13 AB07 AB36 BB01 BB14 BC06 BD02 BD04 BD08 CA13 4G069 AA02 AA03 BB08A BB10A BB10B BC31A BC31B BC62A BC67A BC67CA02 CA12B
Claims (3)
と、（Ｂ）銅、マンガン、コバルト及びニッケル化合物
の中から選ばれた少なくとも１種の反応触媒を共存さ
せ、ヒドラジンを酸化分解することを特徴とするヒドラ
ジン含有排水の処理方法。1. A hydrazine-containing wastewater is made to coexist with (A) a percarbonate and (B) at least one reaction catalyst selected from copper, manganese, cobalt and nickel compounds to oxidatively decompose hydrazine. A method for treating hydrazine-containing wastewater, comprising:
るヒドラジンの０.５〜３倍当量とする請求項１記載の
ヒドラジン含有排水の処理方法。2. The method for treating hydrazine-containing wastewater according to claim 1, wherein the percarbonate as the component (A) is used in an amount of 0.5 to 3 equivalents of hydrazine contained in the wastewater.
２mg／リットルになるように共存させる請求項１又は２
記載のヒドラジン含有排水の処理方法。3. The component (B) having a metal concentration of 0.01 to less.
3. The method according to claim 1, wherein the coexistence is 2 mg / liter.
A method for treating hydrazine-containing wastewater according to the above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11263999A JP4399854B2 (en) | 1999-04-20 | 1999-04-20 | Treatment method of waste water containing hydrazine |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11263999A JP4399854B2 (en) | 1999-04-20 | 1999-04-20 | Treatment method of waste water containing hydrazine |
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| Publication Number | Publication Date |
|---|---|
| JP2000301171A true JP2000301171A (en) | 2000-10-31 |
| JP4399854B2 JP4399854B2 (en) | 2010-01-20 |
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ID=14591772
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11263999A Expired - Fee Related JP4399854B2 (en) | 1999-04-20 | 1999-04-20 | Treatment method of waste water containing hydrazine |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003010687A (en) * | 2001-07-03 | 2003-01-14 | Kurita Water Ind Ltd | Oxidative decomposition catalyst for organic matter and treatment method for organic matter-containing wastewater using the same |
| DE102007036617A1 (en) | 2007-08-02 | 2009-02-05 | Epc Engineering Consulting Gmbh | Process for the safe and efficient degradation of hydrazine and hydrazine sulfate |
| KR102100874B1 (en) * | 2018-12-28 | 2020-04-14 | 한국원자력연구원 | Method for removing hydrazine in solution |
| CN113371875A (en) * | 2021-06-04 | 2021-09-10 | 广东工业大学 | Method for removing cyanobacterial bloom in water body |
-
1999
- 1999-04-20 JP JP11263999A patent/JP4399854B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003010687A (en) * | 2001-07-03 | 2003-01-14 | Kurita Water Ind Ltd | Oxidative decomposition catalyst for organic matter and treatment method for organic matter-containing wastewater using the same |
| DE102007036617A1 (en) | 2007-08-02 | 2009-02-05 | Epc Engineering Consulting Gmbh | Process for the safe and efficient degradation of hydrazine and hydrazine sulfate |
| WO2009016259A1 (en) * | 2007-08-02 | 2009-02-05 | Epc Engineering Consulting Gmbh | Method and system for non-hazardous and efficient degradation of hydrazine and hydrazine sulfate |
| KR102100874B1 (en) * | 2018-12-28 | 2020-04-14 | 한국원자력연구원 | Method for removing hydrazine in solution |
| CN113371875A (en) * | 2021-06-04 | 2021-09-10 | 广东工业大学 | Method for removing cyanobacterial bloom in water body |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4399854B2 (en) | 2010-01-20 |
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