JPH06154787A - Device for removing nitrogen - Google Patents
Device for removing nitrogenInfo
- Publication number
- JPH06154787A JPH06154787A JP33380192A JP33380192A JPH06154787A JP H06154787 A JPH06154787 A JP H06154787A JP 33380192 A JP33380192 A JP 33380192A JP 33380192 A JP33380192 A JP 33380192A JP H06154787 A JPH06154787 A JP H06154787A
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- JP
- Japan
- Prior art keywords
- nitrogen
- biological
- water
- nitrite
- gas
- 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.)
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- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
- Treatment Of Water By Oxidation Or Reduction (AREA)
- Catalysts (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は例えば飲料用原水や下排
水中に含まれる硝酸態窒素を除去する装置に関するもの
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for removing nitrate nitrogen contained in raw water for drinking or sewage.
【０００２】[0002]
【従来の技術】近年飲料用原水、特に井水中の酸化態窒
素濃度が高くなっており、例えば硝酸態窒素濃度が飲料
用基準である10mgN/リットルを超す場合も多くなってい
る。このような酸化態窒素の上昇原因としては、農地へ
の窒素肥料の施肥が自然環境中で硝化されることが主と
してあげられる。2. Description of the Related Art In recent years, raw water for drinking, particularly well water, has a high concentration of oxidized nitrogen, and for example, the concentration of nitrate nitrogen often exceeds 10 mgN / liter which is the standard for beverages. The main cause of such an increase in oxidized nitrogen is that fertilization of agricultural land with nitrogen fertilizer is nitrified in a natural environment.
【０００３】酸化態窒素はメトヘモグロビン血症原因物
質として知られ、また強力な変異原性物質であるＮ−ニ
トロソ化合物の前駆物質でもある。このように、酸化態
窒素はヒトに重大な健康障害をもたらす物質であり、特
に飲用に供する水中からの除去が必要とされている。Oxidized nitrogen is known as a causative agent of methemoglobinemia, and is also a precursor of an N-nitroso compound which is a potent mutagenic substance. Thus, oxidized nitrogen is a substance that causes serious health problems in humans, and needs to be removed from water for drinking in particular.
【０００４】従来の除去技術としては、陰イオン交換樹
脂を用いたイオン交換法が、代表的な方法としてあげら
れるが、当該方法は水中の酸化態窒素を濃縮除去するも
のであり、濃縮液の処理が必要となり、根本的な酸化態
窒素の除去方法とはいえない。As a conventional removal technique, an ion exchange method using an anion exchange resin can be mentioned as a typical method. However, this method concentrates and removes oxidized nitrogen in water. It requires a treatment and cannot be said to be a fundamental method for removing oxidized nitrogen.
【０００５】別の除去技術として、生物学的処理法があ
る。これには水素供与体としてエタノール、酢酸等の有
機物を用いる従属栄養性細菌による方法、水素供与体と
して水素ガスを用いる独立栄養性細菌による方法等があ
げられる。これらの方法は、水中の酸化態窒素を下記化
学反応式により無害な窒素ガスにするものであり、根本
的な酸化態窒素の除去方法である。Another removal technique is a biological treatment method. Examples of the method include a method using a heterotrophic bacterium using an organic substance such as ethanol and acetic acid as a hydrogen donor, and a method using an autotrophic bacterium using hydrogen gas as a hydrogen donor. These methods are to remove oxidized nitrogen in water into harmless nitrogen gas by the following chemical reaction formula, and are fundamental methods for removing oxidized nitrogen.
【０００６】・従属栄養性細菌による反応（水素供与
体：エタノール） ６ＮＯ3 - ＋Ｃ2 Ｈ5 ＯＨ→６ＮＯ2 - ＋２ＣＯ2 ＋３Ｈ2 Ｏ … ６ＮＯ2 - ＋Ｃ2 Ｈ5 ＯＨ→３Ｎ2 ＋２ＣＯ2 ＋３Ｈ2 Ｏ＋６ＯＨ- …Reaction by heterotrophic bacteria (hydrogen donor: ethanol) 6NO 3 − + C 2 H 5 OH → 6NO 2 − + 2CO 2 + 3H 2 O 6NO 2 − + C 2 H 5 OH → 3N 2 + 2CO 2 + 3H 2 O + 6OH - ...
【０００７】・独立栄養性細菌による反応 ２ＮＯ3 - ＋２Ｈ2 →２ＮＯ2 - ＋２Ｈ2 Ｏ … ２ＮＯ2 - ＋３Ｈ2 →Ｎ2 ＋２Ｈ2 Ｏ＋２ＯＨ- …Reaction by autotrophic bacteria 2NO 3 − + 2H 2 → 2NO 2 − + 2H 2 O 2NO 2 − + 3H 2 → N 2 + 2H 2 O + 2OH −
【０００８】[0008]
【発明が解決しようとする課題】しかしながら、生物学
的処理法にも以下のような問題点がある。すなわち硝酸
態窒素を生物学的処理法で、窒素にほぼ完全に分解しよ
うとすると、生物学的処理の常として反応速度が通常の
化学反応に較べて遅いために容積負荷をかなり低く抑え
なければならず、装置の容量が大きくなり、一方高い容
積負荷をかけるためには、微生物の量を多くしなければ
ならないが、実際にはそれ程容易ではない。However, the biological treatment method also has the following problems. That is, if it is attempted to almost completely decompose nitrate nitrogen into nitrogen by a biological treatment method, the reaction rate as biological treatment is slower than that of a normal chemical reaction, and therefore the volume load must be kept fairly low. However, in order to increase the capacity of the device, while increasing the volume load, the amount of microorganisms must be increased, but it is not so easy in practice.
【０００９】また亜硝酸態窒素からの還元反応（化学反
応式あるいは）は、微生物の状態が良ければ問題は
ないが、馴養時間の不足や反応条件の変動時には、前記
反応が進まず、亜硝酸態窒素の蓄積が起こり、処理水中
に検出されることになり好ましくない。The reduction reaction from nitrite nitrogen (chemical reaction formula or) is not a problem if the microorganisms are in good condition, but the reaction does not proceed when the acclimatization time is insufficient or the reaction conditions change, and Accumulation of dissolved nitrogen occurs and is detected in the treated water, which is not preferable.
【００１０】本発明は、生物学的処理法における上記問
題点を解決するものであり、装置容量を小さくし、かつ
飲用に適したあるいは河川等に放流しても何ら問題のな
い安全な水を常に供給できる窒素除去装置を提供するこ
とを目的とするものである。The present invention solves the above-mentioned problems in the biological treatment method, reduces the apparatus capacity, and produces safe water suitable for drinking or having no problem even when discharged into a river or the like. It is an object of the present invention to provide a nitrogen removing device that can be constantly supplied.
【００１１】[0011]
【課題を解決するための手段】上記目的を達成するため
になされた本発明は、水中の硝酸態窒素を水素供与体の
存在下に微生物を用いて生物学的に分解し、積極的に亜
硝酸態窒素を生成させる生物学的手段と水中の亜硝酸態
窒素を水素ガスの存在下に水素添加触媒を用いて窒素ガ
スに還元する化学的手段とを備え、前記生物学的手段の
下流に前記化学的手段を配置接続したことを特徴とする
窒素除去装置を要旨とするものである。The present invention, which has been made to achieve the above object, is a method in which nitrate nitrogen in water is biologically decomposed by using a microorganism in the presence of a hydrogen donor to positively decompose the nitrogen. A biological means for producing nitrate nitrogen and a chemical means for reducing nitrite nitrogen in water to nitrogen gas using a hydrogenation catalyst in the presence of hydrogen gas are provided, and downstream of the biological means. A gist of a nitrogen removing device characterized in that the chemical means is arranged and connected.
【００１２】本発明において「水中の硝酸態窒素を水素
供与体の存在下において微生物を用いて生物学的に分解
し、積極的に亜硝酸態窒素を生成させる」とは、硝酸態
窒素をほぼ完全に窒素ガスに分解させるのではなく、前
記した反応をできるだけ亜硝酸態窒素生成の段階までで
留めること、すなわち、従属栄養性細菌を用いる場合は
前記の式の反応、独立栄養性細菌を用いる場合は前記
の式の反応が専ら進行するように制御することを意味
する。In the present invention, "biologically decomposing nitrate nitrogen in water using a microorganism in the presence of a hydrogen donor to positively produce nitrite nitrogen" means that nitrate nitrogen is almost Instead of completely decomposing into nitrogen gas, the above reaction is stopped as far as possible to the stage of nitrite nitrogen production, that is, when using a heterotrophic bacterium, the reaction of the above formula, using an autotrophic bacterium In the case, it means controlling so that the reaction of the above formula proceeds exclusively.
【００１３】そして、硝酸態窒素の分解反応を亜硝酸態
窒素生成の段階で止めて良いのであれば、硝酸態窒素を
生物学的手段によってほぼ完全に窒素ガスに分解する場
合に較べて装置の容積負荷を著しく高くすることがで
き、したがって生物学的反応槽の容量を小さくすること
ができる。If the decomposition reaction of nitrate nitrogen can be stopped at the stage of producing nitrite nitrogen, the apparatus will be compared to the case where nitrate nitrogen is almost completely decomposed into nitrogen gas by biological means. The volume loading can be significantly higher and thus the volume of the biological reactor can be smaller.
【００１４】なお、生物学的手段における窒素負荷を高
くし、硝酸態窒素の分解反応を亜硝酸態窒素生成の段階
に留めて良いのであれば、供給する水素供与体の量も前
記の式またはの式から計算される化学当量だけで十
分である。If the nitrogen load in the biological means can be increased and the decomposition reaction of nitrate nitrogen can be limited to the stage of producing nitrite nitrogen, the amount of the hydrogen donor supplied can also be the above formula or Only the chemical equivalent calculated from the formula is sufficient.
【００１５】一方、上記生物学的手段で生成した亜硝酸
態窒素は、後段の化学的手段において水素添加触媒の触
媒作用によって速やかに窒素ガスに分解される。この反
応は、触媒による化学反応であって、瞬時に進行するか
ら、装置としては極めて小型なものとすることができ
る。したがって、生物学的手段と化学的手段との両手段
を必要とするといっても、硝酸態窒素を生物学的手段単
独でほぼ完全に窒素ガスに分解する場合よりも装置全体
としては小規模な装置で済み、かつ好ましくない亜硝酸
態窒素を化学的手段によって完全に分解、除去すること
ができる。On the other hand, the nitrite nitrogen produced by the biological means is rapidly decomposed into nitrogen gas by the catalytic action of the hydrogenation catalyst in the latter chemical means. Since this reaction is a chemical reaction by a catalyst and proceeds instantaneously, the device can be made extremely small. Therefore, even though both biological and chemical means are required, the apparatus as a whole has a smaller scale than that in the case of decomposing nitrate nitrogen into nitrogen gas almost completely by the biological means alone. The apparatus is sufficient and undesired nitrite nitrogen can be completely decomposed and removed by chemical means.
【００１６】本発明において採用される生物学的手段と
は、硝酸態窒素を含む原水と微生物とを水素供与体の存
在下に効率良く接触できる構造のものであればいかなる
ものでもよく、例えば槽内に活性炭、セラミックボール
等の粒状物や各種形状のプラスチック等の担体を充填
し、当該担体の表面に微生物を付着させて、処理するよ
うにしたいわゆる固定床式の反応装置や活性炭、セラミ
ックボール等の粒状物表面に微生物を付着させて流動さ
せながら処理するようにしたいわゆる流動床式の反応装
置等があげられる。The biological means employed in the present invention may be any one having a structure capable of efficiently contacting raw water containing nitrate nitrogen with microorganisms in the presence of a hydrogen donor, for example, a tank. Granules such as activated carbon and ceramic balls or carriers of various shapes such as plastics are filled in the inside, and so-called fixed bed type reactors or activated carbons and ceramic balls in which microorganisms are attached to the surface of the carrier and treated A so-called fluidized bed reactor in which microorganisms are attached to the surface of a granular material such as the above and treated while being fluidized can be used.
【００１７】また本発明において採用される化学的手段
とは、水素ガスの存在下において、亜硝酸態窒素を含む
原水と水素添加触媒とを効率良く接触させ、下記化学反
応式により亜硝酸態窒素に水素を付加させることによ
り、窒素ガスと水とに分解するものである。 ２ＮＯ2 - ＋３Ｈ2 →Ｎ2 ＋２Ｈ2 Ｏ＋２ＯＨ- … ここで用いる触媒としては例えばパラジウム（Ｐｄ）、
ロジウム（Ｒｈ）、白金（Ｐｔ）等の金属があげられる
が、経済的な面及び還元力の点からパラジウムが好まし
い。接触方式としては、バッチ式でも連続式でもよい。The chemical means adopted in the present invention is that the raw water containing nitrite nitrogen and the hydrogenation catalyst are efficiently contacted in the presence of hydrogen gas, and the nitrous nitrogen is represented by the following chemical reaction formula. When hydrogen is added to, it decomposes into nitrogen gas and water. 2NO 2 - + 3H 2 → N 2 + 2H 2 O + 2OH - ... for example palladium as catalyst used here (Pd),
Examples of the metal include rhodium (Rh) and platinum (Pt). Palladium is preferred from the economical point of view and reducing power. The contact method may be a batch method or a continuous method.
【００１８】以下に本発明の実施態様を図面に基づいて
説明する。Embodiments of the present invention will be described below with reference to the drawings.
【００１９】図１は本発明の実施態様の一例を示すフロ
ーの説明図であり、生物学的反応槽（１）は下部に原水
供給ライン（２）と上部に生物処理水ライン（３）とが
連通されている。反応槽（１）内には、表面に従属栄養
性脱窒菌からなる微生物を予め付着させた活性炭担体
（５）を充填している。反応塔（７）は前記生物処理水
ライン（３）を介して生物学的反応槽（１）の下流に配
置接続した化学的反応塔であり、当該反応塔（７）は下
部に前記生物処理水ライン（３）が上部に最終処理水ラ
イン（６）が連通されている。反応塔（７）内には、粒
状のパラジウム触媒（９）を充填している。FIG. 1 is an explanatory view of a flow showing an example of an embodiment of the present invention. The biological reaction tank (1) has a raw water supply line (2) at the lower part and a biological treated water line (3) at the upper part. Are in communication. The reaction tank (1) is filled with an activated carbon carrier (5) to the surface of which microorganisms consisting of heterotrophic denitrifying bacteria are previously attached. The reaction tower (7) is a chemical reaction tower arranged and connected downstream of the biological reaction tank (1) via the biological treatment water line (3), and the reaction tower (7) is provided at the bottom with the biological treatment tank. The water line (3) is connected to the upper part of the final treated water line (6). The reaction tower (7) is filled with a granular palladium catalyst (9).
【００２０】硝酸態窒素を含有する原水は、原水供給ラ
イン（２）を介して、反応槽（１）に流入する。なお、
原水供給ライン（２）に栄養源添加ライン（４）を連通
し、当該栄養源添加ライン（４）を介して原水中に、水
素供与体となる有機物（エタノール、酢酸など）か、更
に必要に応じて無機塩類等の栄養源が夫々添加される。Raw water containing nitrate nitrogen flows into the reaction tank (1) through the raw water supply line (2). In addition,
The raw water supply line (2) is connected to the nutrient source addition line (4), and an organic substance (ethanol, acetic acid, etc.) serving as a hydrogen donor is further required in the raw water through the nutrient source addition line (4). Accordingly, nutrient sources such as inorganic salts are added respectively.
【００２１】上記活性炭担体（５）の表面には従属栄養
性脱窒菌からなる微生物を積極的に繁殖させており、当
該微生物の働きにより水中の硝酸態窒素を前出の化学反
応式により積極的に亜硝酸態窒素に還元し、その処理
水は生物処理水ライン（３）を介して後段のパラジウム
触媒（９）が充填された反応塔（７）にその下部より導
入される。導入された生物処理水は、反応塔（７）内を
上昇流で流れ、塔内に充填されているパラジウム触媒
（９）の働きにより反応塔（７）の下部に連通された水
素ガス供給ライン（８）を介して導入された水素ガスと
生物処理水中の亜硝酸態窒素が反応し、前出の化学反応
式により速やかに窒素ガスと水とに分解される。Microorganisms consisting of heterotrophic denitrifying bacteria are actively propagated on the surface of the activated carbon carrier (5), and the nitrate nitrogen in the water is positively propagated by the above-mentioned chemical reaction formula by the action of the microorganisms. Is reduced to nitrite nitrogen, and the treated water is introduced into the reaction column (7) filled with the palladium catalyst (9) in the latter stage from the lower part thereof through the biological treated water line (3). The introduced biologically treated water flows in the reaction tower (7) in an upward flow, and the hydrogen gas supply line communicated with the lower part of the reaction tower (7) by the action of the palladium catalyst (9) filled in the tower. The hydrogen gas introduced via (8) reacts with the nitrite nitrogen in the biologically treated water, and is rapidly decomposed into nitrogen gas and water according to the above chemical reaction formula.
【００２２】硝酸態窒素が完全に除去された最終処理水
は、最終処理水ライン（６）を介して取り出される。ま
た分解によって生成された窒素ガスは塔（７）の上部に
設けたガス排出ライン（10）を介して外部に排出され
る。The final treated water from which nitrate nitrogen has been completely removed is taken out through the final treated water line (6). The nitrogen gas produced by the decomposition is discharged to the outside through a gas discharge line (10) provided in the upper part of the tower (7).
【００２３】なお、生物処理水ライン（３）の途中に精
密ろ過膜等の膜を用いた濁質分離手段を設置し、生物学
的反応槽（１）の生物処理水中に含まれる懸濁物質を除
去するようにしても良い。また、化学的反応塔（７）の
後段に空気曝気槽を設け、水中に残存する水素ガスの除
去や揮発性有機物の除去を行っても良い。A suspended matter separating means using a membrane such as a microfiltration membrane is installed in the biological treated water line (3), and the suspended substance contained in the biological treated water in the biological reaction tank (1). May be removed. Further, an air aeration tank may be provided in the latter stage of the chemical reaction tower (7) to remove hydrogen gas remaining in water or volatile organic substances.
【００２４】図２は本発明の実施態様の別の例を示すフ
ローの説明図である。生物学的反応槽（１）は下部に原
水供給ライン（２）と水素ガス供給ライン（11）、上部
に生物処理水ライン（３）とが連通されている。反応槽
（１）内には表面に独立栄養性脱窒菌からなる微生物を
予め付着させた繊維状プラスチック担体（12）を充填し
ている。反応槽（15）は生物処理水ライン（３）を介し
て、生物学的反応槽（１）の下流に配置接続した化学的
反応槽であり、当該反応槽（15）は上部に前記生物処理
水ライン（３）及び最終処理水ライン（６）が夫々連通
されているとともに、当該反応槽（15）内には粉末状の
パラジウム触媒を浮遊させている。FIG. 2 is an explanatory diagram of a flow showing another example of the embodiment of the present invention. The biological reaction tank (1) is connected at its lower part with a raw water supply line (2) and a hydrogen gas supply line (11) and at its upper part with a biologically treated water line (3). The reaction tank (1) is filled with a fibrous plastic carrier (12) on the surface of which microorganisms composed of autotrophic denitrifying bacteria are previously attached. The reaction tank (15) is a chemical reaction tank arranged and connected downstream of the biological reaction tank (1) via a biological treated water line (3), and the reaction tank (15) is provided at the upper portion with the biological treatment. The water line (3) and the final treated water line (6) are connected to each other, and a powdery palladium catalyst is suspended in the reaction tank (15).
【００２５】硝酸態窒素を含有する原水は、原水供給ラ
イン（２）を介して反応槽（１）に流入し、また水素ガ
ス供給ライン（11）を経て水素供与体となる水素ガスが
供給される。なお、必要に応じて原水に無機塩類等の栄
養源を添加してもよい。Raw water containing nitrate nitrogen flows into the reaction tank (1) through the raw water supply line (2), and hydrogen gas serving as a hydrogen donor is supplied through the hydrogen gas supply line (11). It A nutrient source such as an inorganic salt may be added to the raw water if necessary.
【００２６】このように繊維状プラスチック担体（12）
の表面に独立栄養性脱窒菌からなる微生物を積極的に繁
殖させているので、当該微生物の働きにより、水中の硝
酸態窒素は前出の化学反応式により、積極的に亜硝酸
態窒素に還元され、当該処理水は生物処理水ライン
（３）を介して後段のパラジウム触媒（９）が浮遊して
いる反応槽（15）にその上部より導入される。Thus, the fibrous plastic carrier (12)
Since the microorganisms consisting of autotrophic denitrifying bacteria are actively propagated on the surface of, the nitrate nitrogen in the water is actively reduced to nitrite nitrogen by the above-mentioned chemical reaction formula by the action of the microorganism. Then, the treated water is introduced from above through the biological treated water line (3) into the reaction tank (15) in which the latter-stage palladium catalyst (9) is suspended.
【００２７】導入された生物処理水は反応槽（15）内の
パラジウム触媒（９）の働きにより、反応槽（15）の下
部に連通された水素ガス供給ライン（８）を介して導入
された水素ガスと生物処理水中の亜硝酸態窒素が反応
し、前出の化学反応式により、速やかに窒素ガスと水
とに分解される。このとき攪拌機（13）により被反応物
と触媒とが効率良く接触するように攪拌する。The introduced biologically treated water was introduced through the hydrogen gas supply line (8) connected to the lower part of the reaction tank (15) by the action of the palladium catalyst (9) in the reaction tank (15). Hydrogen gas reacts with nitrite nitrogen in biologically treated water, and is rapidly decomposed into nitrogen gas and water according to the above chemical reaction formula. At this time, the stirrer (13) stirs the reactant so that the catalyst and the catalyst come into contact with each other efficiently.
【００２８】硝酸態窒素が完全に除去された最終処理水
は、最終処理水ライン（６）を介して取り出される。ま
た、分解によって生成された窒素ガスは槽（15）の上部
に設けたガス排出ライン（10）を介して外部に排出され
る。なお、（14）はパラジウム触媒粒子が処理水中に流
出するのを防止するための阻流板である。The final treated water from which nitrate nitrogen has been completely removed is taken out through the final treated water line (6). Further, the nitrogen gas produced by the decomposition is discharged to the outside through a gas discharge line (10) provided in the upper part of the tank (15). In addition, (14) is a baffle plate for preventing the palladium catalyst particles from flowing out into the treated water.
【００２９】また、化学的反応槽（15）の後段に精密ろ
過膜等の膜を設置し、最終処理水と共に流出してくる一
部触媒を捕捉し、再び反応槽（７）に戻すようにしても
よい。Further, a membrane such as a microfiltration membrane is installed in the latter stage of the chemical reaction tank (15) so that a part of the catalyst flowing out together with the final treated water is captured and returned to the reaction tank (7) again. May be.
【００３０】[0030]
【発明の効果】本発明によれば、生物学的手段における
容積負荷を高めることによって原水中に含有されている
硝酸態窒素を生物学的手段によって積極的に亜硝酸態窒
素に還元し、その後段に設置した化学的手段によって生
成された亜硝酸態窒素を速やかに分解、除去することが
できるので、生物学的手段単独で水中の硝酸態窒素をほ
ぼ完全に窒素ガスに分解する場合に較べて、装置容量を
小型化することができ、かつ硝酸態窒素濃度が低く、酸
化態窒素の検出されない飲用に適した水を得ることがで
きる。According to the present invention, the nitrate load contained in the raw water is positively reduced to nitrite nitrogen by the biological means by increasing the volume load in the biological means. Since nitrite nitrogen generated by the chemical means installed on the stage can be decomposed and removed quickly, compared to the case where the nitrate nitrogen in the water is almost completely decomposed into nitrogen gas by the biological means alone. As a result, the device capacity can be reduced, and the concentration of nitrate nitrogen is low, and water suitable for drinking in which oxidized nitrogen is not detected can be obtained.
【００３１】[0031]
【実施例】次に本発明の実施例について以下に説明す
る。EXAMPLES Examples of the present invention will be described below.
【００３２】（実施例１）：図１ 容量１リットルの反応槽（１）内に、表面に従属栄養性
脱窒菌からなる微生物を予め着生させた活性炭担体
（５）を充填した。模擬原水として水道水中に試薬のＫ
ＮＯ3 を、水中の硝酸態窒素濃度が20mgN/リットルとな
るように、またＫＨ2 ＰＯ4 を水中のリン濃度が 0.2mg
P/リットルとなるように添加したものを用いた。水素供
与体としてのエタノール量は、流入してくる硝酸態窒素
を亜硝酸態窒素に還元するのに必要な量の 1.2倍、すな
わち 13mg/リットルに制限して添加した。(Example 1): FIG. 1 A reaction tank (1) having a capacity of 1 liter was filled with an activated carbon carrier (5) on the surface of which microorganisms composed of heterotrophic denitrifying bacteria were preliminarily grown. K as a reagent in tap water as simulated raw water
NO 3 is added so that the concentration of nitrate nitrogen in water is 20 mgN / liter, and KH 2 PO 4 is added in the concentration of 0.2 mg of phosphorus in water.
What was added so that it might become P / liter was used. The amount of ethanol as a hydrogen donor was limited to 1.2 times the amount required to reduce the inflowing nitrate nitrogen to nitrite nitrogen, that is, 13 mg / liter.
【００３３】また、容量20mlの反応塔（７）内に直径約
１mmの粒状のＰｄ−Ａｌ2 Ｏ3 触媒（Ｐｄ含量５％）５
ｇを充填した。反応塔（７）へ供給する水素ガス量は、
反応槽（１）で硝酸態窒素が完全に亜硝酸態窒素に還元
された時の窒素量に対して窒素ガスに還元するのに必要
な量の３倍とした。また、槽内を中性付近にするため炭
酸ガを供給した。Further, a granular Pd-Al 2 O 3 catalyst (Pd content 5%) 5 having a diameter of about 1 mm was placed in a reaction tower (7) having a capacity of 20 ml.
g. The amount of hydrogen gas supplied to the reaction tower (7) is
The amount of nitrogen when the nitrate nitrogen was completely reduced to nitrite nitrogen in the reaction tank (1) was set to 3 times the amount required to reduce the nitrogen gas. Further, carbon dioxide was supplied in order to make the inside of the tank near neutral.
【００３４】まず、微生物の馴養を充分行った後、窒素
負荷（反応槽１ｍ3 、１日当りのＮ換算の硝酸態窒素
量）0.1kgN/m3 ／日として運転を開始した。First, after sufficiently acclimatizing the microorganisms, the operation was started with a nitrogen load (reactor tank 1 m 3 , the amount of nitrate nitrogen equivalent to N per day) of 0.1 kgN / m 3 / day.
【００３５】その後徐々に負荷を上げ４週間後には窒素
負荷4.5kgN/m3 ／日とした。この時の処理性能は、生物
処理水については硝酸態窒素除去率平均90％、亜硝酸態
窒素濃度は平均 18mg/リットルとなり、除去された硝酸
態窒素はほぼ 100％亜硝酸態窒素に分解されていた。し
かし、この生物処理水を反応塔（７）によって処理した
最終処理水については亜硝酸態窒素は検出されなかっ
た。After that, the load was gradually increased, and after 4 weeks, the nitrogen load was set to 4.5 kgN / m 3 / day. Regarding the treatment performance at this time, the average removal rate of nitrate nitrogen for biologically treated water was 90%, the average nitrite nitrogen concentration was 18 mg / liter, and the removed nitrate nitrogen was decomposed to almost 100% nitrite nitrogen. Was there. However, nitrite nitrogen was not detected in the final treated water obtained by treating the biological treated water with the reaction tower (7).
【００３６】（実施例２）：図２ 容量１リットルの生物学的反応槽（１）内に、表面に独
立栄養性脱窒菌からなる微生物を予め着生させた繊維状
プラスチック担体（12）を充填した。模擬原水として水
道水中にＫＮＯ3 20mgN/リットル、ＫＨ2 ＰＯ4 0.2mg
P/リットルとなるように添加したものを用いた。水素供
与体としての水素ガス量は、流入してくる硝酸態窒素を
窒素ガスに還元するのに必要な量の３倍とした。(Example 2): FIG. 2 In a biological reaction tank (1) having a volume of 1 liter, a fibrous plastic carrier (12) having a surface on which microorganisms composed of autotrophic denitrifying bacteria has been preliminarily grown. Filled. KNO 3 20mgN / liter, KH 2 PO 4 0.2mg in tap water as simulated raw water
What was added so that it might become P / liter was used. The amount of hydrogen gas as a hydrogen donor was set to 3 times the amount required to reduce the inflowing nitrate nitrogen to nitrogen gas.
【００３７】また、容量 500mlの化学的反応槽（15）内
に直径約 150μｍの粉末状のＰｄ−Ａｌ2 Ｏ3 触媒（Ｐ
ｄ含量５％）５ｇをマグネティックスターラーで均一に
なるように攪拌した。反応槽（15）へ供給する水素ガス
量は反応槽（１）で水中に溶存した水素ガス量で充分で
はあるが、必要に応じて供給した。Further, in a chemical reaction tank (15) having a capacity of 500 ml, a powdery Pd-Al 2 O 3 catalyst (P
5 g (d content 5%) was stirred uniformly with a magnetic stirrer. The amount of hydrogen gas supplied to the reaction tank (15) is sufficient if the amount of hydrogen gas dissolved in water in the reaction tank (1) is sufficient, but it was supplied as needed.
【００３８】まず、微生物の馴養を充分行った後、窒素
負荷１ kgN/m3 ／日として運転を開始した。開始１週間
後には、生物処理水中の硝酸態窒素除去率平均95％以
上、亜硝酸態窒素は１ mg/リットル以下となり、生物処
理のみで原水中の硝酸態窒素をほぼ完全に窒素ガスに分
解できていた。なお、この時最終処理水ライン（６）か
ら得られる最終処理水中には亜硝酸態窒素は検出されな
かった。First, after sufficiently acclimatizing the microorganisms, the operation was started under a nitrogen load of 1 kgN / m 3 / day. One week after the start, the average removal rate of nitrate nitrogen in biologically treated water was 95% or more, and nitrite nitrogen was 1 mg / liter or less. Nitric acid nitrogen in raw water was almost completely decomposed into nitrogen gas only by biological treatment. It was done. At this time, nitrite nitrogen was not detected in the final treated water obtained from the final treated water line (6).
【００３９】その後負荷を上げ、窒素負荷をそれぞれ
２、３、４、及び５ kgN/m3 ／日とした時の処理性能を
調べた。これらの結果を次の表１に示した。なお、上記
各処理のいずれにおいても、最終処理水に亜硝酸態窒素
は検出されなかった。After that, the load was increased, and the treatment performance was examined when the nitrogen loads were 2, 3, 4, and 5 kgN / m 3 / day, respectively. The results are shown in Table 1 below. In each of the above treatments, nitrite nitrogen was not detected in the final treated water.
【００４０】[0040]
【表１】 [Table 1]
【００４１】（実施例３）：図２ 容量１リットルの生物学的反応槽（１）内に、表面に独
立栄養性脱窒菌からなる微生物を予め着生させた繊維状
プラスチック担体（12）を充填した。模擬原水として水
道水中にＫＮＯ3 を20mgN/リットルになるように添加
し、更にＫＨ2 ＰＯ4 を 0.2mgP/リットルとなるように
添加したものを用いた。水素供与体としての水素ガス量
は流入してくる硝酸態窒素を亜硝酸態窒素に還元するた
めに必要な量の1.2 倍に制限して供給した。また、槽内
を中性付近にするため炭酸ガスを供給した。(Example 3): FIG. 2 In a biological reaction tank (1) having a volume of 1 liter, a fibrous plastic carrier (12) having a surface on which microorganisms composed of autotrophic denitrifying bacteria was preliminarily grown. Filled. As simulated raw water, tap water was used in which KNO 3 was added at 20 mgN / liter and KH 2 PO 4 was added at 0.2 mgP / liter. The amount of hydrogen gas as a hydrogen donor was limited to 1.2 times the amount required to reduce the inflowing nitrate nitrogen to nitrite nitrogen. Further, carbon dioxide gas was supplied to bring the inside of the tank to near neutral.
【００４２】上記反応槽の後段には、容量 500mlの化学
的反応槽（15）内に直径約 150μｍの粉末状のＰｄ−Ａ
ｌ2 Ｏ3 触媒（Ｐｄ含量５％）５ｇを投入し、マグネテ
ィックスターラーで均一になるように攪拌した。反応槽
（15）へ供給する水素ガス量は反応槽（１）で硝酸態窒
素が完全に亜硝酸態窒素に還元された時の窒素量に対し
て窒素ガスに還元するのに必要な量の３倍とした。After the above reaction tank, powdery Pd-A having a diameter of about 150 μm was placed in a chemical reaction tank (15) having a capacity of 500 ml.
5 g of 1 2 O 3 catalyst (Pd content 5%) was added, and the mixture was stirred with a magnetic stirrer so as to be uniform. The amount of hydrogen gas supplied to the reaction tank (15) is the amount necessary to reduce the nitrogen gas to nitrogen gas when the nitrate nitrogen is completely reduced to nitrite nitrogen in the reaction tank (1). It was set to 3 times.
【００４３】まず、微生物の馴養を充分行った後、窒素
負荷0.1kgN/m3 ／日として運転を開始した。その後、徐
々に負荷を上げ、６週間後には窒素負荷4.5kgN/m3 ／日
とした。この時、処理性能は、生物処理水については、
硝酸態窒素除去率平均90％、亜硝酸態窒素濃度は平均 1
8mg/リットルとなったが、最終処理水については、亜硝
酸態窒素は検出されなかった。First, after sufficiently acclimatizing the microorganisms, the operation was started under a nitrogen load of 0.1 kgN / m 3 / day. After that, the load was gradually increased, and after 6 weeks, the nitrogen load was set to 4.5 kgN / m 3 / day. At this time, the treatment performance is
Nitrate nitrogen removal rate average 90%, nitrite nitrogen concentration average 1
Although it was 8 mg / liter, nitrite nitrogen was not detected in the final treated water.
【００４４】ちなみに水素ガスを、原水中の硝酸態窒素
をＮ2 ガスまで還元するのに充分な量供給し、原水中の
硝酸態窒素を生物学的手段単独でほぼ完全に窒素ガスに
しようとすると、実施例２で述べたように処理性能は、
窒素負荷２ kgN/m3 ／日以下では硝酸態窒素除去率95％
以上で、亜硝酸態窒素生成濃度も平均３ mg/リットルと
比較的少ないが、窒素負荷が２ kgN/m3 ／日を超えると
亜硝酸態窒素の生成量が著しく増加し、そのままでは処
理水を飲用に供することができないなど、実用上問題が
生じる。By the way, hydrogen gas is supplied in an amount sufficient to reduce the nitrate nitrogen in the raw water to N 2 gas, so that the nitrate nitrogen in the raw water is almost completely converted into the nitrogen gas by the biological means alone. Then, as described in the second embodiment, the processing performance is
Nitrate nitrogen removal rate 95% when nitrogen load is 2 kgN / m 3 / day or less
As a result, the nitrite nitrogen production concentration was relatively low, averaging 3 mg / liter, but when the nitrogen load exceeded 2 kgN / m 3 / day, the nitrite nitrogen production increased remarkably, and the treated water was left as it was. There is a problem in practical use, such as being unable to be used for drinking.
【００４５】上記実施例２及び実施例３から明らかなご
とく、生物学的手段単独では、窒素負荷はせいぜい２ k
gN/m3 ／日程度が限度であるが、生物学的手段の後段に
化学的手段を組合せることで窒素負荷には制約がなくな
り、工業的実施上有利である。As is apparent from Examples 2 and 3, the nitrogen load is 2 k at most with the biological means alone.
Although there is a limit of about gN / m 3 / day, by combining chemical means after the biological means, there is no restriction on the nitrogen load, which is advantageous in industrial practice.
【００４６】なお、独立栄養性細菌を用いた場合の窒素
負荷の上限については特に制約されないが、硝酸態窒素
の亜硝酸態窒素への分解率及び装置の操業効率の面か
ら、窒素負荷は３ kgN/m3 ／日〜10 kgN/m3 ／日の範囲
とするのが好ましい。The upper limit of the nitrogen load when using autotrophic bacteria is not particularly limited, but the nitrogen load is 3 in view of the decomposition rate of nitrate nitrogen into nitrite nitrogen and the operating efficiency of the apparatus. The range of kgN / m 3 / day to 10 kgN / m 3 / day is preferable.
【図１】本発明の実施例で用いた脱窒装置の概要説明図
である。FIG. 1 is a schematic explanatory diagram of a denitrification device used in an example of the present invention.
【図２】本発明の実施例２及び３で用いた脱窒装置の概
要説明図である。FIG. 2 is a schematic explanatory diagram of a denitrification device used in Examples 2 and 3 of the present invention.
１ 生物学的反応槽 ２ 原水供給ライン ３ 生物処理水ライン ４ 栄養源添加ライン ５ 活性炭担体 ６ 最終処理水ライン ７ 化学的反応塔 ８ 水素ガス供給ライン ９ パラジウム触媒 10 ガス排出ライン 11 水素ガス供給ライン 12 繊維状プラスチック担体 13 攪拌機 14 阻流板 15 化学的反応槽 1 Biological reaction tank 2 Raw water supply line 3 Biological treated water line 4 Nutrient source addition line 5 Activated carbon carrier 6 Final treated water line 7 Chemical reaction tower 8 Hydrogen gas supply line 9 Palladium catalyst 10 Gas discharge line 11 Hydrogen gas supply line 12 Fibrous plastic carrier 13 Stirrer 14 Barrier plate 15 Chemical reaction tank
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成５年１１月８日[Submission date] November 8, 1993
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２９[Name of item to be corrected] 0029
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２９】また、化学的反応槽（１５）の後段に精密
ろ過膜等の膜を設置し、最終処理水と共に流出してくる
一部触媒を捕捉し、再び反応槽（１５）に戻すようにし
てもよい。Further, a membrane such as a microfiltration membrane is installed in the latter stage of the chemical reaction tank (15) so that a part of the catalyst flowing out together with the final treated water is captured and returned to the reaction tank (15) again. May be.
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００３０[Name of item to be corrected] 0030
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００３０】[0030]
【発明の効果】本発明によれば、生物学的手段における
容積負荷を高めることによって、あるいは水素供与体の
供給量を制限することによって原水中に含有されている
硝酸態窒素を生物学的手段によって積極的に亜硝酸態窒
素に還元し、その後段に設置した化学的手段によって生
成された亜硝酸態窒素を速やかに分解、除去することが
できるので、生物学的手段単独で水中の硝酸態窒素をほ
ぼ完全に窒素ガスに分解する場合に較べて、装置容量を
小型化することができ、かつ硝酸態窒素濃度が低く、酸
化態窒素の検出されない飲用に適した水を得ることがで
きる。According to the present invention, in biological means
By increasing the volume load, or of the hydrogen donor
By limiting the supply amount, nitrate nitrogen contained in raw water is actively reduced to nitrite nitrogen by biological means, and nitrite nitrogen produced by chemical means installed in the subsequent stage. Since it can decompose and remove nitrogen rapidly, the device capacity can be made smaller and the nitrate state can be reduced compared to the case where nitrate nitrogen in water is almost completely decomposed into nitrogen gas by biological means alone. It is possible to obtain water suitable for drinking where the nitrogen concentration is low and oxidized nitrogen is not detected.
【手続補正３】[Procedure 3]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００３３[Correction target item name] 0033
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００３３】また、容量２０ｍｌの反応塔（７）内に直
径約１ｍｍの粒状のＰｄ−Ａｌ２Ｏ３触媒（Ｐｄ含量５
％）５ｇを充填した。反応塔（７）へ供給する水素ガス
量は、反応槽（１）で硝酸態窒素が完全に亜硝酸態窒素
に還元された時の窒素量に対して窒素ガスに還元するの
に必要な量の３倍とした。また、槽内を中性付近にする
ため炭酸ガスを供給した。Further, a granular Pd-Al 2 O 3 catalyst (Pd content: 5) having a diameter of about 1 mm was placed in a reaction tower (7) having a capacity of 20 ml.
%) 5 g. The amount of hydrogen gas supplied to the reaction tower (7) is the amount required to reduce the nitrogen gas to the nitrogen gas when the nitrate nitrogen is completely reduced to nitrite nitrogen in the reaction tank (1). 3 times. Further, carbon dioxide gas was supplied to bring the inside of the tank to near neutral.
Claims (5)
に微生物を用いて生物学的に分解し、積極的に亜硝酸態
窒素を生成させる生物学的手段と、水中の亜硝酸態窒素
を水素ガスの存在下に水素添加触媒を用いて窒素ガスに
還元する化学的手段とを備え、前記生物学的手段の下流
に前記化学的手段を配置接続したことを特徴とする窒素
除去装置。1. A biological means for biologically decomposing nitrate nitrogen in water using a microorganism in the presence of a hydrogen donor to positively generate nitrite nitrogen, and nitrite in water. And a chemical means for reducing nitrogen to nitrogen gas using a hydrogenation catalyst in the presence of hydrogen gas, wherein the chemical means is arranged and connected downstream of the biological means. .
スを用い、容積負荷（反応槽１ｍ3 、１日当りのＮ換算
の硝酸態窒素量）を３ kgN/m3 ／日以上に設定した請求
項１記載の窒素除去装置。2. The biological means uses hydrogen gas as a hydrogen donor, and the volume load (reactor tank 1 m 3 , the amount of nitrate nitrogen in N per day) is set to 3 kgN / m 3 / day or more. The nitrogen removing device according to claim 1.
スを用い、該水素ガス量を硝酸態窒素を亜硝酸態窒素に
還元するための化学当量に設定した請求項１または２に
記載の窒素除去装置。3. The method according to claim 1 or 2, wherein the biological means uses hydrogen gas as a hydrogen donor and sets the amount of hydrogen gas to a chemical equivalent for reducing nitrate nitrogen to nitrite nitrogen. Nitrogen removal device.
を用い、該有機物量を硝酸態窒素を亜硝酸態窒素に還元
するための化学当量に設定した請求項１記載の窒素除去
装置。4. The nitrogen removing apparatus according to claim 1, wherein the biological means uses an organic substance as a hydrogen donor and sets the amount of the organic substance to a chemical equivalent for reducing nitrate nitrogen to nitrite nitrogen.
ジウム触媒である請求項１〜４までのいずれか１項記載
の窒素除去装置。5. The nitrogen removing apparatus according to claim 1, wherein the hydrogenation catalyst used for the chemical means is a palladium catalyst.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33380192A JP2947684B2 (en) | 1992-11-20 | 1992-11-20 | Nitrogen removal equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33380192A JP2947684B2 (en) | 1992-11-20 | 1992-11-20 | Nitrogen removal equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06154787A true JPH06154787A (en) | 1994-06-03 |
| JP2947684B2 JP2947684B2 (en) | 1999-09-13 |
Family
ID=18270111
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33380192A Expired - Fee Related JP2947684B2 (en) | 1992-11-20 | 1992-11-20 | Nitrogen removal equipment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2947684B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996025364A1 (en) * | 1995-02-17 | 1996-08-22 | Solvay Umweltchemie Gmbh | Combined chemical and biological water treatment process |
| KR20200017433A (en) * | 2017-06-08 | 2020-02-18 | 닛산 가가쿠 가부시키가이샤 | Method of manufacturing substrate for flexible device |
| CN112429844A (en) * | 2020-10-23 | 2021-03-02 | 同济大学 | Method and system for deep denitrification of sewage |
-
1992
- 1992-11-20 JP JP33380192A patent/JP2947684B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996025364A1 (en) * | 1995-02-17 | 1996-08-22 | Solvay Umweltchemie Gmbh | Combined chemical and biological water treatment process |
| KR20200017433A (en) * | 2017-06-08 | 2020-02-18 | 닛산 가가쿠 가부시키가이샤 | Method of manufacturing substrate for flexible device |
| CN112429844A (en) * | 2020-10-23 | 2021-03-02 | 同济大学 | Method and system for deep denitrification of sewage |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2947684B2 (en) | 1999-09-13 |
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