JPH09206790A - Treatment of waste water of steel product pickling containing nitrate nitrogen - Google Patents
Treatment of waste water of steel product pickling containing nitrate nitrogenInfo
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- JPH09206790A JPH09206790A JP4216196A JP4216196A JPH09206790A JP H09206790 A JPH09206790 A JP H09206790A JP 4216196 A JP4216196 A JP 4216196A JP 4216196 A JP4216196 A JP 4216196A JP H09206790 A JPH09206790 A JP H09206790A
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- Prior art keywords
- wastewater
- waste water
- nitrate nitrogen
- hydrogen donor
- hardly
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、硝酸性窒素を含有
する鋼材の酸洗排水から、低コストで硝酸性窒素を除去
するための処理方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a treatment method for removing nitrate nitrogen at low cost from pickling wastewater of steel containing nitrate nitrogen.
【０００２】[0002]
【従来の技術】ステンレス鋼材等の酸洗工程からは、硝
酸性窒素（ＮＯ3 −Ｎ）を１００〜２０００ｍｇ／ｌと
比較的高濃度に含有した排水が排出される。現在、窒素
の排出濃度は排水基準によって規制されているため、排
水中の硝酸性窒素を除去する必要がある。2. Description of the Related Art Wastewater containing a relatively high concentration of nitrate nitrogen (NO 3 -N) of 100 to 2000 mg / l is discharged from the pickling process of stainless steel materials. Currently, the emission concentration of nitrogen is regulated by wastewater standards, so it is necessary to remove nitrate nitrogen in wastewater.
【０００３】排水中の硝酸性窒素を除去する方法として
は、物理化学的方法と生物学的方法が挙げられるが、通
常、物理化学的方法は数ｇ以上の高濃度で硝酸性窒素を
含有する排水へ適用され、数千ｍｇ／ｌ程度までに硝酸
性窒素を含有する排水へは生物学的方法が適用される。As a method for removing nitrate nitrogen in waste water, there are physicochemical methods and biological methods. Usually, physicochemical methods contain nitrate nitrogen at a high concentration of several g or more. It is applied to wastewater, and biological methods are applied to wastewater containing nitrate nitrogen up to about several thousand mg / l.
【０００４】生物学的脱窒法は、排水中の硝酸性窒素ま
たは亜硝酸性窒素（ＮＯ2 −Ｎ）を、水素供与体が存在
する嫌気状態において、脱窒菌と呼ばれる細菌の働きに
よって窒素ガスに還元し、除去する処理方法である。水
素供与体としては、グルコース、イソプロピルアルコー
ル、酢酸、アセトン等多くの物質が使用可能であるが、
取り扱い易さや反応速度の大きさ等の理由から、メタノ
ールが頻繁に用いられている。また、都市下水のよう
に、排水中の窒素量に対して充分の量の有機物が同時に
含有されている場合は、その有機物を水素供与体として
使用することも可能である。In the biological denitrification method, nitrate nitrogen or nitrite nitrogen (NO 2 —N) in waste water is converted into nitrogen gas by the action of bacteria called denitrifying bacteria in an anaerobic state where a hydrogen donor is present. It is a processing method of reducing and removing. As the hydrogen donor, many substances such as glucose, isopropyl alcohol, acetic acid, and acetone can be used,
Methanol is frequently used for reasons such as easy handling and high reaction rate. In addition, when a sufficient amount of organic matter is contained at the same time with respect to the amount of nitrogen in the wastewater, such as city sewage, the organic matter can be used as a hydrogen donor.
【０００５】[0005]
【発明が解決しようとする課題】鋼材の酸洗排水中に
は、化学的酸素要求量〔ＣＯＤ〕として１０〜２０ｍｇ
／ｌ程度と有機物がほとんど含有されていないため、外
部から水素供与体を添加する必要がある。The chemical oxygen demand [COD] is 10 to 20 mg in the pickling waste water of steel materials.
It is necessary to add a hydrogen donor from the outside since the organic substance is hardly contained at about 1 / l.
【０００６】例えば、メタノールを水素供与体として利
用する場合、脱窒反応式は化１のようになる。For example, when methanol is used as a hydrogen donor, the denitrification reaction formula is as shown in Chemical formula 1.
【０００７】[0007]
【化１】６ＮＯ3 - ＋５ＣＨ3 ＯＨ → ３Ｎ2 ＋５Ｃ
Ｏ2 ＋７Ｈ2 Ｏ＋６ＯＨ- [Formula 1] 6NO 3 - + 5CH 3 OH → 3N 2 + 5C
O 2 + 7H 2 O + 6OH -
【０００８】上式から、脱窒反応の際に必要となるメタ
ノール添加量は、重量比で表すとＣＨ3 ＯＨ／ＮＯ3 −
Ｎ＝１．９（ＮＯ3 −Ｎは窒素としての重量）となる。
しかし、メタノールは脱窒菌の増殖にも用いられるた
め、実際のメタノール添加量は、理論量よりも更に３０
〜４０％増加する（例えば、「水処理工学」、技報堂出
版、ｐ．３０１、１９９０）。From the above equation, the amount of methanol added required for the denitrification reaction is expressed as a weight ratio of CH 3 OH / NO 3 −.
N = 1.9 (NO 3 -N weight as nitrogen) becomes.
However, since methanol is also used for the growth of denitrifying bacteria, the actual amount of methanol added is 30% more than the theoretical amount.
-40% increase (for example, "Water Treatment Engineering", Gihodo Publishing, p.301, 1990).
【０００９】このように、メタノールを水素供与体とし
て新たに添加することは、処理コストの上昇へとつなが
ってしまう。そこで、有機物のみを含有し、アンモニア
性窒素や硝酸性窒素等の窒素化合物を含有しない排水を
水素供与体として添加し、メタノールの全量または一部
の代用とすることが考えられる。As described above, the new addition of methanol as a hydrogen donor leads to an increase in processing cost. Therefore, it is conceivable that wastewater containing only organic substances and not containing nitrogen compounds such as ammoniacal nitrogen and nitrate nitrogen is added as a hydrogen donor to substitute all or part of methanol.
【００１０】例えば、製鉄所内の冷延鋼板製造工程や亜
鉛メッキ、錫メッキなどの表面処理鋼材製造工程から
は、金属イオンや有機物を大量に含有し、かつｐＨが２
〜３と低い酸性排水が排出される（それぞれ、以下「冷
延排水」、「メッキ排水」という）。これらの排水は、
通常、アルカリ凝集沈殿法（中和法）によって金属イオ
ンを沈殿除去し、残りの有機物を過塩素酸やフェントン
試薬（過酸化水素＋鉄塩）等の薬品によって酸化分解し
た後に放流される。従って、アルカリ凝集沈殿後の排水
中には、脱窒菌にとって有害な金属イオンが含有され
ず、大量の有機物のみが含有されるため、脱窒菌の水素
供与体として利用可能である。For example, from a cold rolled steel sheet manufacturing process in a steelworks or a surface treated steel material manufacturing process such as galvanizing or tin plating, a large amount of metal ions and organic substances are contained and the pH is 2 or less.
Acidic wastewater as low as ~ 3 is discharged (hereinafter referred to as "cold rolling wastewater" and "plating wastewater", respectively). These drains are
Usually, metal ions are precipitated and removed by an alkaline coagulation precipitation method (neutralization method), and the remaining organic matter is oxidatively decomposed by a chemical such as perchloric acid or Fenton's reagent (hydrogen peroxide + iron salt), and then discharged. Therefore, the wastewater after alkaline coagulation precipitation does not contain metal ions harmful to the denitrifying bacteria but contains only a large amount of organic substances, and can be used as a hydrogen donor for the denitrifying bacteria.
【００１１】しかし、それらの排水中に含有される有機
物は、主に界面活性剤やメッキ添加剤、例えばフェノー
ルスルホン酸といった微生物にとって難分解性の有機物
である。これらの有機物を直接、脱窒のための水素供与
体として添加した場合、脱窒菌は有機物を分解すること
ができない、もしくは非常に遅い速度でしか分解できな
いため、有機物中の水素は効率良く利用されない。従っ
て、メタノールを水素供与体とした場合と比較して、脱
窒速度が極端に低下するばかりではなく、脱窒菌（活性
汚泥）の沈降性が不良になる、亜硝酸性窒素が処理水中
に残存するなどの問題が生じてしまう。However, the organic substances contained in the wastewater are organic substances which are hardly decomposed by microorganisms such as surfactants and plating additives, for example, phenolsulfonic acid. When these organic substances are directly added as hydrogen donors for denitrification, denitrifying bacteria cannot decompose the organic substances, or can decompose only at a very slow rate, so the hydrogen in the organic substances is not efficiently used. . Therefore, compared with the case where methanol is used as a hydrogen donor, not only the denitrification rate is extremely decreased, but also the sedimentation of denitrifying bacteria (activated sludge) becomes poor, and nitrite nitrogen remains in the treated water. It causes problems such as doing.
【００１２】更に、一部の界面活性剤、例えばラウリル
硫酸ナトリウムやメッキ添加剤、例えばエトキシレート
αナフトールスルホン酸は脱窒菌にとって有毒であるた
め、このような有機物をそのまま脱窒槽へ添加した場
合、脱窒菌の脱窒能力が停止し、もしくは脱窒菌そのも
のがすべて死滅してしまう危険性もある。Further, some of the surfactants such as sodium lauryl sulfate and plating additives such as ethoxylate α-naphtholsulfonic acid are toxic to the denitrifying bacteria. Therefore, when such an organic substance is directly added to the denitrification tank, There is a risk that the denitrifying ability of the denitrifying bacteria will stop, or that all the denitrifying bacteria themselves will be killed.
【００１３】本発明の目的は、生物難分解性有機物を含
む排水を分解処理した後に水素供与体として利用して、
低コストで硝酸性窒素を除去するための鋼材酸洗排水の
処理方法を提供することである。An object of the present invention is to utilize wastewater containing bio-hardly decomposable organic matter as a hydrogen donor after decomposing it,
It is an object of the present invention to provide a method for treating steel pickling wastewater for removing nitrate nitrogen at low cost.
【００１４】[0014]
【課題を解決するための手段】本発明は、硝酸性窒素を
含有する鋼材酸洗排水を生物学的に脱窒処理する際に、
生物難分解性有機物を含む排水中に二酸化チタンを浸漬
もしくは過酸化水素を添加した後紫外線を照射する光分
解によって、またはオゾン分解によって、排水中の生物
難分解性有機物を脱窒菌が分解容易な物質まで分解処理
して水素供与体として脱窒槽に供給することを特徴とす
る硝酸性窒素を含有する鋼材酸洗排水の処理方法であ
る。なお、生物難分解性有機物を脱窒菌が分解容易な物
質にまで分解処理した排水の脱窒槽への供給量は、脱窒
槽の酸化還元電位（ＯＲＰ／銀−塩化銀電極基準）が−
２００〜−１００ｍＶとなるように制御することが望ま
しい。The present invention provides a method for biologically denitrifying a steel pickling wastewater containing nitrate nitrogen.
It is easy for denitrifying bacteria to decompose biodifficult-to-biodegradable organic substances in wastewater by photolysis by immersing titanium dioxide in wastewater containing bio-difficult-to-biodegradable organic substances or adding hydrogen peroxide and then irradiating with ultraviolet rays, or by ozonolysis. A method for treating a steel pickling wastewater containing nitrate nitrogen, which comprises decomposing the substance and supplying it as a hydrogen donor to a denitrification tank. In addition, the amount of the wastewater obtained by decomposing bio-hardly degradable organic substances into substances that can be easily decomposed by denitrifying bacteria to the denitrification tank depends on the redox potential of the denitrification tank (ORP / silver-silver chloride electrode standard).
It is desirable to control the voltage to be 200 to -100 mV.
【００１５】二酸化チタンを始めとする半導体光触媒へ
紫外線を照射すると、半導体光触媒中の電子が励起さ
れ、正孔と呼ばれる部位が生成する。正孔は非常に強力
な酸化力を持つため、Ｈ2 ＯやＯＨ- イオンから電子を
捕獲し、ＯＨラジカルを生成する。また、過酸化水素へ
紫外線を照射した場合、過酸化水素が分解してＯＨラジ
カルを生成する。これらのＯＨラジカルは非常に強力な
酸化力を持つため、たとえ生物難分解性有機物であって
も迅速に酸化分解し、最終的にＣＯ2 とＨ2 Ｏのような
無機物質にまで分解することが可能である。When a semiconductor photocatalyst such as titanium dioxide is irradiated with ultraviolet rays, the electrons in the semiconductor photocatalyst are excited and a site called a hole is generated. Since holes have a very strong oxidizing power, they capture electrons from H 2 O and OH − ions to generate OH radicals. Further, when the hydrogen peroxide is irradiated with ultraviolet rays, the hydrogen peroxide decomposes to generate OH radicals. Since these OH radicals have extremely strong oxidizing power, even if they are hardly biodegradable organic substances, they are rapidly oxidatively decomposed and finally decomposed into inorganic substances such as CO 2 and H 2 O. Is possible.
【００１６】一方、生物難分解性有機物は、オゾン分解
によって酸化分解することも可能である。オゾン分解
は、オゾンの直接的な、またはオゾンが分解して生成し
たＯＨラジカルの間接的な酸化反応によって有機物を酸
化分解する方法であり、光分解の場合と異なり、生物難
分解性有機物を完全に無機物質にまで分解することはで
きないが、より低分子量の他の有機物（中間生成物）へ
分解することは可能である。On the other hand, the hardly biodegradable organic matter can also be oxidatively decomposed by ozone decomposition. Ozonolysis is a method of oxidatively decomposing organic matter by direct oxidation of ozone or indirect oxidation reaction of OH radicals generated by decomposition of ozone. It is not possible to decompose into inorganic substances, but it is possible to decompose into other low molecular weight organic substances (intermediate products).
【００１７】冷延排水やメッキ排水等の製鉄所排水中に
含有される界面活性剤やメッキ添加剤を光分解やオゾン
分解で分解する過程の中間生成物として生成するシュウ
酸、ギ酸、マレイン酸等の有機酸、メタノール等のアル
コールは、脱窒菌にとって分解容易な物質であり、有機
物中の水素を効率良く利用することができる。従って、
これらの物質を水素供与体として利用した場合、元の界
面活性剤やメッキ添加剤をそのまま水素供与体とした場
合と比較して、飛躍的に脱窒速度が上昇する。また、原
排水中に微生物にとって有毒な物質が含有される場合、
光分解やオゾン分解によってこれらを無毒な物質にまで
分解することも可能である。Oxalic acid, formic acid, and maleic acid, which are produced as intermediate products in the process of decomposing the surface active agent and plating additive contained in the wastewater of steel mills such as cold-rolled wastewater and plating wastewater by photolysis or ozonolysis. Organic acids such as and alcohols such as methanol are substances that are easily decomposed by denitrifying bacteria, and hydrogen in organic substances can be efficiently used. Therefore,
When these substances are used as a hydrogen donor, the denitrification rate is dramatically increased as compared with the case where the original surfactant or plating additive is used as it is as a hydrogen donor. Also, if the raw wastewater contains substances that are toxic to microorganisms,
It is also possible to decompose these into nontoxic substances by photolysis or ozone decomposition.
【００１８】光分解やオゾン分解による処理時間に関し
ては、対象とする冷延排水、メッキ排水の性状によって
も異なるため、事前の検討が必要である。一般的には、
光分解の場合、排水中の全有機炭素〔ＴＯＣ〕をほぼ完
全に、すなわち約５ｍｇ／ｌ以下程度にまで分解するた
めに必要な時間の１／１０〜２／３程度が望ましい。ま
た、オゾン分解の場合、排水中のＴＯＣを完全に分解す
ることはできないため、ＴＯＣを限界まで分解するため
に必要な時間の１／１０〜１／３程度が望ましい。The treatment time by photolysis or ozone decomposition depends on the properties of the target cold-rolled wastewater and plating wastewater, so that it is necessary to examine it in advance. In general,
In the case of photolysis, 1/10 to 2/3 of the time required to almost completely decompose the total organic carbon [TOC] in the waste water, that is, about 5 mg / l or less is desirable. Further, in the case of ozone decomposition, TOC in the waste water cannot be completely decomposed, and therefore, it is desirable that the time is about 1/10 to 1/3 of the time required to decompose TOC to the limit.
【００１９】光分解またはオゾン分解によって、生物難
分解性有機物を脱窒菌が分解容易な物質にまで分解処理
した排水（以下「分解排水」という）は、水素供与体と
して脱窒槽へ添加する。しかし、鋼材酸洗排水中の硝酸
性窒素濃度、および分解排水中に含有される水素供与体
の種類や濃度は常に変動しているため、その添加量を一
定にすることは難しい。そこで、脱窒槽内の酸化還元電
位（ＯＲＰ／銀−塩化銀電極基準）の値が−２００〜−
１００ｍＶとなるように分解排水の添加量を調整すれ
ば、適切な添加量に制御可能である。すなわち、鋼材酸
洗排水中の硝酸性窒素濃度に対する水素供与体の添加量
が少なすぎる場合、脱窒槽内のＯＲＰは−１００ｍＶよ
りも高い値を示すため、分解排水の添加量を増加し、逆
に、鋼材酸洗排水中の硝酸性窒素濃度に対する水素供与
体の添加量が多すぎる場合、脱窒槽内のＯＲＰは−２０
０ｍＶよりも低い値を示すため、分解排水の添加量を削
減すれば良い。なお、ここで水素供与体の適切な添加量
というのは、理論的および脱窒菌の増殖のために必要な
水素供与体量よりも更に１０〜５０％程度多い値であ
る。Wastewater (hereinafter referred to as "decomposition wastewater") obtained by decomposing bio-hardly decomposable organic substances into substances easily decomposed by denitrifying bacteria by photolysis or ozonolysis (hereinafter referred to as "decomposition wastewater") is added to a denitrification tank as a hydrogen donor. However, since the concentration of nitrate nitrogen in the steel pickling wastewater and the type and concentration of the hydrogen donor contained in the decomposition wastewater are constantly changing, it is difficult to make the addition amount constant. Therefore, the redox potential (ORP / silver-silver chloride electrode reference) in the denitrification tank is -200 to-.
If the amount of decomposition wastewater added is adjusted to 100 mV, it is possible to control the amount of addition appropriately. That is, when the addition amount of the hydrogen donor to the concentration of nitrate nitrogen in the steel pickling wastewater is too small, the ORP in the denitrification tank shows a value higher than −100 mV, so the addition amount of the decomposition wastewater increases and In addition, when the amount of hydrogen donor added to the concentration of nitrate nitrogen in the steel pickling wastewater is too large, the ORP in the denitrification tank is -20.
Since the value is lower than 0 mV, the amount of decomposition wastewater added may be reduced. The appropriate amount of hydrogen donor added here is a value that is about 10 to 50% higher than the theoretical amount of hydrogen donor necessary for the growth of denitrifying bacteria.
【００２０】[0020]
【発明の実施の形態】図１に、本発明を実施するために
使用する処理装置を示す。DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a processing apparatus used to practice the present invention.
【００２１】アルカリ凝集沈殿処理によって重金属を除
去され、界面活性剤やメッキ添加剤等を含有する生物難
分解性有機物を含む排水は、バッチ式の生物難分解性有
機物分解槽１（光分解槽またはオゾン分解槽）内で処理
され、排水中の生物難分解性有機物を脱窒菌が水素供与
体として利用することが容易な物質にまで分解する。分
解排水は水素供与体として調整槽２へ貯蔵し、調整槽２
内のｐＨはｐＨセンサー３、ｐＨ制御装置４によってｐ
Ｈ＝７に調整する。Wastewater containing a bio-hardly-degradable organic substance containing a surfactant, a plating additive, etc., from which heavy metals have been removed by alkali coagulation-sedimentation treatment is a batch-type bio-hardly-degradable organic substance decomposition tank 1 (photolysis tank or It is processed in an ozone decomposing tank) and decomposes bio-hardly-degradable organic substances in wastewater into substances that are easily used by denitrifying bacteria as hydrogen donors. The decomposed wastewater is stored in the adjusting tank 2 as a hydrogen donor, and is stored in the adjusting tank 2
The pH inside is controlled by the pH sensor 3 and pH controller 4
Adjust to H = 7.
【００２２】硝酸性窒素を含有する鋼材酸洗排水は脱窒
槽６へ導入する。脱窒槽６内の脱窒菌には、下水処理場
より採取した活性汚泥を種汚泥として馴養した後の活性
汚泥を用いる。脱窒槽６内は常に攪拌器によって攪拌
し、脱窒槽６内のｐＨはｐＨセンサー３、ｐＨ制御装置
４によって脱窒のために適切なｐＨ＝８に制御する。脱
窒槽６内のＯＲＰはＯＲＰセンサー７によって常時測定
し、測定値に応じてＯＲＰ制御装置８によって分解排水
供給ポンプ５の流量を制御する。脱窒槽６内で硝酸性窒
素を除去した鋼材酸洗排水は好気性微生物槽９へ導入
し、余分に添加された水素供与体を除去したものを最終
処理水とする。Steel pickling wastewater containing nitric nitrogen is introduced into the denitrification tank 6. As the denitrifying bacteria in the denitrification tank 6, the activated sludge obtained by acclimatizing the activated sludge collected from the sewage treatment plant as seed sludge is used. The inside of the denitrification tank 6 is constantly stirred by a stirrer, and the pH inside the denitrification tank 6 is controlled by the pH sensor 3 and the pH control device 4 to an appropriate pH = 8 for denitrification. The ORP in the denitrification tank 6 is constantly measured by the ORP sensor 7, and the flow rate of the decomposition wastewater supply pump 5 is controlled by the ORP controller 8 according to the measured value. The steel material pickling wastewater from which the nitrate nitrogen has been removed in the denitrification tank 6 is introduced into the aerobic microorganism tank 9, and the one from which the hydrogen donor added excessively is removed is used as the final treated water.
【００２３】なお、冷延排水やメッキ排水中に含有され
る有機物が少なく、調整槽２内に貯蔵した分解排水中の
有機物濃度も低い場合、充分な脱窒を行うためには分解
排水の添加量を増加しなければならない。しかし、鋼材
酸洗排水の処理量に対して分解排水の添加量が大きくな
りすぎた場合、脱窒槽６における水理学的滞留時間が短
くなり、脱窒が不良となる危険性がある。そこで、この
ような場合には、水素供与体としてメタノールを併用す
る。すなわち、メタノールタンク１０からメタノールを
調整槽２へ添加することにより、分解排水中の水素供与
体の不足を補う。When the cold-rolled wastewater and the plating wastewater contain a small amount of organic matter and the decomposed wastewater stored in the adjusting tank 2 has a low organic matter concentration, addition of decomposed wastewater is necessary for sufficient denitrification. You have to increase the quantity. However, if the amount of decomposition wastewater added becomes too large with respect to the amount of steel pickling wastewater treated, the hydraulic retention time in the denitrification tank 6 becomes short, and there is a risk that denitrification will be poor. Therefore, in such a case, methanol is also used as a hydrogen donor. That is, by adding methanol from the methanol tank 10 to the adjusting tank 2, the shortage of the hydrogen donor in the decomposition waste water is supplemented.
【００２４】[0024]
【実施例１】本発明の方法で、光分解によって処理した
メッキ排水を水素供与体として、ステンレス鋼板の酸洗
排水中の硝酸性窒素の脱窒を行った。Example 1 Using the plating wastewater treated by photolysis by the method of the present invention as a hydrogen donor, nitrate nitrogen in the pickling wastewater of a stainless steel plate was denitrified.
【００２５】アルカリ剤添加による中和処理によって金
属イオンを除去した後のメッキ排水を、バッチ式の生物
難分解性有機物分解槽１内で１時間光分解処理した。な
お、生物難分解性有機物分解槽１内には二酸化チタン
（ＴｉＯ2 ）をコーティングした基板を設置し、ランプ
には１ｋＷの高圧水銀ランプを用いた。メッキ排水中の
主要な有機物は、生物難分解性のメッキ添加剤であるｐ
−フェノールスルホン酸であるが、光分解後の分解排水
中からはギ酸およびシュウ酸が検出された。The plating wastewater after the metal ions were removed by the neutralization treatment by the addition of an alkaline agent was photodegraded for 1 hour in the batch-type biorefractory organic substance decomposition tank 1. A substrate coated with titanium dioxide (TiO 2 ) was installed in the biodegradable organic substance decomposition tank 1, and a 1 kW high-pressure mercury lamp was used as the lamp. The main organic matter in the plating wastewater is a biodegradable plating additive, p
-For phenol sulfonic acid, formic acid and oxalic acid were detected in the wastewater after decomposition.
【００２６】脱窒槽６の水理学的滞留時間（水素供与体
の添加量は考慮せず）は５ｈｒ、好気性微生物槽９の滞
留時間は３ｈｒとした。The hydraulic retention time in the denitrification tank 6 (without considering the amount of hydrogen donor added) was 5 hr, and the retention time in the aerobic microorganism tank 9 was 3 hr.
【００２７】表１にメッキ排水（中和処理後）、分解排
水、鋼材酸洗排水原水、脱窒槽出口水、最終処理水の水
質の平均値を示す。Table 1 shows the average values of the plating effluent (after neutralization treatment), decomposition effluent, steel pickling effluent raw water, denitrification tank outlet water, and final treated water.
【００２８】[0028]
【表１】 [Table 1]
【００２９】鋼材酸洗排水原水中の硝酸性窒素は脱窒槽
６において大半が除去され、最終処理水中の硝酸性窒素
濃度は８ｍｇ／ｌであった。また、脱窒槽出口水に含有
されていた余分な水素供与体は好気性微生物槽９におい
て大半が除去された。Most of the nitrate nitrogen in the raw water of the steel pickling wastewater was removed in the denitrification tank 6, and the concentration of nitrate nitrogen in the final treated water was 8 mg / l. Most of the excess hydrogen donor contained in the denitrification tank outlet water was removed in the aerobic microorganism tank 9.
【００３０】[0030]
【実施例２】本発明の方法で、オゾン分解によって処理
したメッキ排水を水素供与体として、ステンレス鋼板の
酸洗排水中の硝酸性窒素の脱窒を行った。[Example 2] Using the plating wastewater treated by ozone decomposition by the method of the present invention as a hydrogen donor, denitrification of nitrate nitrogen in the pickling wastewater of a stainless steel plate was performed.
【００３１】アルカリ剤添加による中和処理によって金
属イオンを除去した後のメッキ排水を、バッチ式の生物
難分解性有機物分解槽１内で１時間オゾン分解処理し
た。なお、オゾンの発生量は排水１リットル当たり０．
５ｇ／ｈｒとした。メッキ排水中の主要な有機物は、生
物難分解性のメッキ添加剤であるｐ−フェノールスルホ
ン酸であるが、オゾン分解後の分解排水中からはギ酸お
よびシュウ酸が検出された。The plating wastewater after removing the metal ions by the neutralization treatment by the addition of the alkaline agent was subjected to ozone decomposition treatment for 1 hour in the batch type bio-degradable organic substance decomposition tank 1. In addition, the amount of ozone generated is 0.
It was set to 5 g / hr. The main organic matter in the plating wastewater was p-phenolsulfonic acid, which is a biodegradable plating additive, but formic acid and oxalic acid were detected in the decomposed wastewater after ozone decomposition.
【００３２】脱窒槽６の水理学的滞留時間（水素供与体
の添加量は考慮せず）は５ｈｒ、好気性微生物槽９の滞
留時間は３ｈｒとした。The hydraulic retention time in the denitrification tank 6 (without considering the amount of hydrogen donor added) was 5 hr, and the retention time in the aerobic microorganism tank 9 was 3 hr.
【００３３】表２にメッキ排水（中和処理後）、分解排
水、鋼材酸洗排水原水、脱窒槽出口水、最終処理水の水
質の平均値を示す。Table 2 shows the average water quality of plating wastewater (after neutralization treatment), decomposition wastewater, raw water for pickling steel materials, outlet water of denitrification tank, and final treated water.
【００３４】[0034]
【表２】 [Table 2]
【００３５】鋼材酸洗排水原水中の硝酸性窒素は脱窒槽
６においてその大半が除去され、最終処理水中の硝酸性
窒素濃度は５ｍｇ／ｌであった。また、脱窒槽出口水に
含有されていた余分な水素供与体は好気性微生物槽９に
おいて大半が除去された。Most of the nitrate nitrogen in the raw water of the steel pickling wastewater was removed in the denitrification tank 6, and the concentration of nitrate nitrogen in the final treated water was 5 mg / l. Most of the excess hydrogen donor contained in the denitrification tank outlet water was removed in the aerobic microorganism tank 9.
【００３６】[0036]
【実施例３】本発明の方法で、光分解によって処理した
冷延排水を水素供与体として、ステンレス鋼板の酸洗排
水中の硝酸性窒素の脱窒を行った。Example 3 Using the cold-rolled wastewater treated by photolysis by the method of the present invention as a hydrogen donor, denitrification of nitrate nitrogen in the wastewater pickled from stainless steel sheets was performed.
【００３７】アルカリ剤添加による中和処理によって金
属イオンを除去した後の冷延排水を、バッチ式の生物難
分解性有機物分解槽１内で１時間光分解処理した。な
お、生物難分解性有機物分解槽１内には二酸化チタン
（ＴｉＯ2 ）をコーティングした基板を設置し、ランプ
には１ｋＷの高圧水銀ランプを用いた。冷延排水中の主
要な有機物は、生物難分解性の各種界面活性剤である
が、光分解後の分解排水中からはギ酸が検出された。ま
た、この冷延排水中には、有機物がＣＯＤとして１０６
０ｍｇ／ｌしか含有されていなかったため、メタノール
を別途添加した。The cold-rolled wastewater after the metal ions were removed by the neutralization treatment by the addition of an alkaline agent was subjected to a photodecomposition treatment for 1 hour in a batch-type biodegradable organic substance decomposition tank 1. A substrate coated with titanium dioxide (TiO 2 ) was installed in the biodegradable organic substance decomposition tank 1, and a 1 kW high-pressure mercury lamp was used as the lamp. The major organic substances in cold-rolled wastewater are various bio-degradable surfactants, but formic acid was detected in the decomposed wastewater after photolysis. In addition, in this cold-rolled wastewater, organic matter is 106
Since it contained only 0 mg / l, methanol was added separately.
【００３８】脱窒槽６の水理学的滞留時間（水素供与体
の添加量は考慮せず）は５ｈｒ、好気性微生物槽９の滞
留時間は３ｈｒとした。The hydraulic retention time in the denitrification tank 6 (without considering the amount of hydrogen donor added) was 5 hr, and the retention time in the aerobic microorganism tank 9 was 3 hr.
【００３９】表３に冷延排水（中和処理後）、分解排水
（メタノール添加後）、鋼材酸洗排水原水、脱窒槽出口
水、最終処理水の水質の平均値を示す。Table 3 shows the average values of cold rolled waste water (after neutralization treatment), decomposition waste water (after addition of methanol), raw water of steel pickling waste water, outlet water of denitrification tank, and final treated water.
【００４０】[0040]
【表３】 [Table 3]
【００４１】鋼材酸洗排水原水中の硝酸性窒素は脱窒槽
６において大半が除去され、最終処理水中の硝酸性窒素
濃度は１ｍｇ／ｌであった。また、脱窒槽出口水に含有
されていた余分な水素供与体は好気性微生物槽９におい
て大半が除去された。Most of the nitrate nitrogen in the raw water of the steel pickling wastewater was removed in the denitrification tank 6, and the concentration of nitrate nitrogen in the final treated water was 1 mg / l. Most of the excess hydrogen donor contained in the denitrification tank outlet water was removed in the aerobic microorganism tank 9.
【００４２】[0042]
【比較例】比較例として、メッキ排水をそのまま水素供
与体として、ステンレス鋼板の酸洗排水中の硝酸性窒素
の脱窒を行った。[Comparative Example] As a comparative example, denitrification of nitric acid nitrogen in the pickling wastewater of the stainless steel plate was performed using the plating wastewater as a hydrogen donor as it was.
【００４３】脱窒槽６の水理学的滞留時間（水素供与体
の添加量は考慮せず）は５ｈｒ、好気性微生物槽９の滞
留時間は３ｈｒとした。The hydraulic retention time in the denitrification tank 6 (without considering the amount of hydrogen donor added) was 5 hr, and the retention time in the aerobic microorganism tank 9 was 3 hr.
【００４４】表４にメッキ排水、鋼材酸洗排水原水、脱
窒槽出口水、最終処理水の水質の平均値を示す。Table 4 shows the average values of the water quality of the plating waste water, the raw water of the steel pickling waste water, the outlet water of the denitrification tank, and the final treated water.
【００４５】[0045]
【表４】 [Table 4]
【００４６】脱窒槽出口水には５１ｍｇ／ｌの硝酸性窒
素が残留し、亜硝酸性窒素も２７ｍｇ／ｌ存在した。ま
た、脱窒槽出口水に含有されていた余分の水素供与体
は、好気性微生物槽９において、その２７％（ＣＯＤと
して）しか除去されなかった。In the denitrification tank outlet water, 51 mg / l of nitrate nitrogen remained and 27 mg / l of nitrite nitrogen was also present. Further, the excess hydrogen donor contained in the denitrification tank outlet water was removed only 27% (as COD) in the aerobic microorganism tank 9.
【００４７】[0047]
【発明の効果】本発明は、生物難分解性有機物を含む排
水を水素供与体として利用して、高効率、低コストで鋼
材酸洗排水中の硝酸性窒素を除去することが可能であ
る。INDUSTRIAL APPLICABILITY According to the present invention, it is possible to remove nitrate nitrogen in the steel pickling wastewater with high efficiency and low cost by utilizing the wastewater containing the biodegradable organic matter as a hydrogen donor.
【図１】本発明の鋼材酸洗排水の処理方法を実施するた
めの装置の例を示す図である。FIG. 1 is a diagram showing an example of an apparatus for carrying out a method for treating a steel material pickling wastewater according to the present invention.
１ 生物難分解性有機物分解槽 ２ 調整槽 ３ ｐＨセンサー ４ ｐＨ制御装置 ５ 分解排水供給ポンプ ６ 脱窒槽 ７ ＯＲＰセンサー ８ ＯＲＰ制御装置 ９ 好気性微生物槽 １０ メタノールタンク １１ メタノール供給ポンプ 1 Bio-hardly decomposable organic matter decomposition tank 2 Adjustment tank 3 pH sensor 4 pH control device 5 Decomposition drainage supply pump 6 Denitrification tank 7 ORP sensor 8 ORP control device 9 Aerobic microorganism tank 10 Methanol tank 11 Methanol supply pump
Claims (4)
物学的に脱窒処理する際に、生物難分解性有機物を脱窒
菌が分解容易な物質にまで分解処理した排水を水素供与
体として脱窒槽に供給することを特徴とする硝酸性窒素
を含有する鋼材酸洗排水の処理方法。1. When a steel product pickling wastewater containing nitrate nitrogen is biologically denitrified, the wastewater obtained by decomposing bio-hardly decomposable organic substances into substances that can be easily decomposed by denitrifying bacteria is a hydrogen donor. A method for treating steel pickling wastewater containing nitrate nitrogen, which comprises supplying the nitrogen to a denitrification tank.
化チタンを浸漬または過酸化水素を添加した後紫外線を
照射する光分解によって、排水中の生物難分解性有機物
を脱窒菌が分解容易な物質まで分解処理して水素供与体
とすることを特徴とする請求項１記載の硝酸性窒素を含
有する鋼材酸洗排水の処理方法。2. A biodegradable organic substance in wastewater is easily decomposed by a denitrifying bacterium by photolysis by immersing titanium dioxide in wastewater containing a hardly biodegradable organic substance or adding hydrogen peroxide and then irradiating with ultraviolet rays. The method for treating a steel pickling wastewater containing nitrate nitrogen according to claim 1, wherein the substance is decomposed to obtain a hydrogen donor.
解性有機物を脱窒菌が分解容易な物質まで分解処理して
水素供与体とすることを特徴とする請求項１記載の硝酸
性窒素を含有する鋼材酸洗排水の処理方法。3. Nitrogen-containing nitrogen according to claim 1, which is characterized by decomposing biologically hardly-decomposable organic matter in wastewater into a substance that is easily decomposed by denitrifying bacteria by ozonolysis to form a hydrogen donor. Method for treating steel pickling wastewater.
な物質にまで分解処理した排水の脱窒槽への供給量を、
脱窒槽の酸化還元電位（ＯＲＰ／銀−塩化銀電極基準）
が−２００〜−１００ｍＶとなるように制御することを
特徴とする請求項１〜３のいずれか記載の硝酸性窒素を
含有する鋼材酸洗排水の処理方法。4. A supply amount of wastewater obtained by decomposing bio-hardly-degradable organic matter into a substance that can be easily decomposed by denitrifying bacteria to a denitrification tank.
Redox potential of denitrification tank (ORP / silver-silver chloride electrode standard)
Is controlled to be -200 to -100 mV. 4. The method for treating steel pickling wastewater containing nitrate nitrogen according to claim 1, wherein
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4216196A JPH09206790A (en) | 1996-02-06 | 1996-02-06 | Treatment of waste water of steel product pickling containing nitrate nitrogen |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4216196A JPH09206790A (en) | 1996-02-06 | 1996-02-06 | Treatment of waste water of steel product pickling containing nitrate nitrogen |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09206790A true JPH09206790A (en) | 1997-08-12 |
Family
ID=12628242
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4216196A Withdrawn JPH09206790A (en) | 1996-02-06 | 1996-02-06 | Treatment of waste water of steel product pickling containing nitrate nitrogen |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09206790A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000254683A (en) * | 1999-03-09 | 2000-09-19 | Yaskawa Electric Corp | Method for controlling supply of excess sludge to sewage treatment facility and biological reaction vessel |
| KR100306206B1 (en) * | 1999-06-14 | 2001-09-24 | 정명식 | Method and equipment for the treatment of wastewater containing nitrate-nitrogen |
| JP2002336891A (en) * | 2001-05-17 | 2002-11-26 | Kurabo Ind Ltd | Decomposition system for hardly decomposable material |
| JP2010201423A (en) * | 1999-06-10 | 2010-09-16 | Bicom:Kk | High-concentration culture method of denitrifying bacterium contained in activated sludge |
| US20120085702A1 (en) * | 2008-12-01 | 2012-04-12 | Rowanwood Ip Inc. | Sewage nitrate removal by free-draining asphyxiant filtration and carbon addition |
| CN108059309A (en) * | 2018-01-30 | 2018-05-22 | 深圳职业技术学院 | A kind of plating method for processing organic wastewater and device |
| CN114455776A (en) * | 2021-12-21 | 2022-05-10 | 中煤科工集团杭州研究院有限公司 | Stainless steel pickling wastewater treatment method based on biological denitrification |
| CN114685007A (en) * | 2022-02-16 | 2022-07-01 | 江苏顺发电热材料有限公司 | Treatment method capable of simultaneously treating pickling wastewater and washing wastewater |
-
1996
- 1996-02-06 JP JP4216196A patent/JPH09206790A/en not_active Withdrawn
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000254683A (en) * | 1999-03-09 | 2000-09-19 | Yaskawa Electric Corp | Method for controlling supply of excess sludge to sewage treatment facility and biological reaction vessel |
| JP2010201423A (en) * | 1999-06-10 | 2010-09-16 | Bicom:Kk | High-concentration culture method of denitrifying bacterium contained in activated sludge |
| KR100306206B1 (en) * | 1999-06-14 | 2001-09-24 | 정명식 | Method and equipment for the treatment of wastewater containing nitrate-nitrogen |
| JP2002336891A (en) * | 2001-05-17 | 2002-11-26 | Kurabo Ind Ltd | Decomposition system for hardly decomposable material |
| US20120085702A1 (en) * | 2008-12-01 | 2012-04-12 | Rowanwood Ip Inc. | Sewage nitrate removal by free-draining asphyxiant filtration and carbon addition |
| US8652329B2 (en) * | 2008-12-01 | 2014-02-18 | Rowanwood Ip Inc. | Sewage nitrate removal by free-draining asphyxiant filtration and carbon addition |
| CN108059309A (en) * | 2018-01-30 | 2018-05-22 | 深圳职业技术学院 | A kind of plating method for processing organic wastewater and device |
| CN114455776A (en) * | 2021-12-21 | 2022-05-10 | 中煤科工集团杭州研究院有限公司 | Stainless steel pickling wastewater treatment method based on biological denitrification |
| CN114685007A (en) * | 2022-02-16 | 2022-07-01 | 江苏顺发电热材料有限公司 | Treatment method capable of simultaneously treating pickling wastewater and washing wastewater |
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