JP6801415B2

JP6801415B2 - Wastewater treatment equipment and wastewater treatment method

Info

Publication number: JP6801415B2
Application number: JP2016238484A
Authority: JP
Inventors: 朋樹川岸; 紗代佐野
Original assignee: Mitsubishi Chemical Corp
Current assignee: Mitsubishi Chemical Corp
Priority date: 2016-02-05
Filing date: 2016-12-08
Publication date: 2020-12-16
Anticipated expiration: 2036-12-08
Also published as: JP2017140610A

Description

本発明は、有機態窒素およびアンモニア態窒素の少なくとも一方を含む廃水の処理装置および廃水の処理方法に関する。 The present invention relates to a wastewater treatment apparatus containing at least one of organic nitrogen and ammonia nitrogen and a method for treating wastewater.

アンモニアを含有する廃水（窒素含有廃水）を生物学的処理する方法としては、一般的に消化液循環方式や内生脱窒方式などが知られている。
消化液循環方式では、まず、原水（廃水）中のアンモニア態窒素を硝化細菌によって好気的条件下で亜硝酸態窒素または硝酸態窒素に変換する。その後、脱窒細菌によって有機物を還元力として無酸素条件下で亜硝酸態窒素または硝酸態窒素を窒素ガスに還元する。 As a method for biologically treating wastewater containing ammonia (wastewater containing nitrogen), a digestive juice circulation method and an endogenous denitrification method are generally known.
In the digestive juice circulation method, first, ammonia nitrogen in raw water (wastewater) is converted into nitrite nitrogen or nitrate nitrogen by nitrifying bacteria under aerobic conditions. Then, denitrifying bacteria reduce nitrite nitrogen or nitrate nitrogen to nitrogen gas under anoxic conditions using organic matter as a reducing power.

硝化細菌は、アンモニア態窒素を亜硝酸に酸化するアンモニア酸化細菌と、亜硝酸態窒素を硝酸態窒素に酸化する亜硝酸酸化細菌との総称である。
一方、脱窒細菌は、無酸素条件下において亜硝酸態窒素または硝酸態窒素を電子受容体とし、有機物を電子供与体として利用することによって、亜硝酸態窒素または硝酸態窒素を窒素ガスにまで還元する微生物である。 Nitrifying bacteria are a general term for ammonia-oxidizing bacteria that oxidize ammonia nitrogen to nitrite and nitrite-oxidizing bacteria that oxidize nitrite nitrogen to nitrate nitrogen.
On the other hand, denitrifying bacteria convert nitrite nitrogen or nitrate nitrogen into nitrogen gas by using nitrite nitrogen or nitrate nitrogen as an electron acceptor and using an organic substance as an electron donor under anoxic conditions. It is a reducing bacterium.

近年、畜産、食品などの高濃度のアンモニアを含有する廃水を処理する方法として、アンモニア態窒素を好気的に窒素ガスに変えて脱窒することが可能なアルカリゲネス・フェカリスＮｏ４株（ＦＥＲＭＰ−２１８１４）を用いた処理法が提案されている（例えば、特許文献１、２参照）。 In recent years, as a method for treating wastewater containing a high concentration of ammonia in livestock and food products, Alcaligenes faecalis No. 4 strain (FERM P-), which can aerobically convert ammonia nitrogen into nitrogen gas and denitrify it. A treatment method using 21814) has been proposed (see, for example, Patent Documents 1 and 2).

アルカリゲネス・フェカリスＮｏ４株（ＦＥＲＭＰ−２１８１４）は、好気的直接窒素ガス化細菌の１種であり、従属栄養細菌でありながら、好気的にアンモニアを窒素ガスにまで直接にガス化できる。加えて、従来の硝化細菌と比較して、アンモニア除去速度が速く、増殖速度も速いといった利点がある。
また、消化液循環方式では処理槽として好気槽（硝化槽）と無酸素槽（脱窒槽）の２槽が必要であるのに対し、アルカリゲネス・フェカリスＮｏ４株（ＦＥＲＭＰ−２１８１４）を用いた処理では好気処理のみで窒素除去が可能であるため、１槽で処理できる利点がある。 Alkalinegenes faecalis No. 4 strain (FERM P-21814) is a kind of aerobic direct nitrogen gasifying bacterium, and although it is a heterotrophic bacterium, it can aerobically gasify ammonia directly into nitrogen gas. In addition, it has the advantages of faster ammonia removal rate and faster growth rate than conventional nitrifying bacteria.
In addition, while the digestive juice circulation method requires two tanks, an aerobic tank (nitrification tank) and an oxygen-free tank (denitrification tank), Alcaligenes faecalis No. 4 strain (FERM P-21814) was used. In the treatment, nitrogen can be removed only by aerobic treatment, so that there is an advantage that the treatment can be performed in one tank.

特開２００２−１９９８７５号公報Japanese Unexamined Patent Publication No. 2002-199875 特開２００８−１０４３６１号公報Japanese Unexamined Patent Publication No. 2008-104361

しかしながら、好気的直接窒素ガス化細菌を用いた廃水の処理を開放系で行うと、窒素除去率が低下することがあった。 However, when wastewater is treated with aerobic direct nitrogen gasifying bacteria in an open system, the nitrogen removal rate may decrease.

本発明は、アンモニア態窒素を好気的に直接窒素ガス化する微生物を用いた廃水の処理を開放系で行う場合であっても、効率的に窒素除去を行うことができる廃水の処理装置および廃水の処理方法を提供することを目的とする。 The present invention provides a wastewater treatment apparatus capable of efficiently removing nitrogen even when the wastewater is treated in an open system using a microorganism that aerobically directly gasifies ammonia nitrogen. The purpose is to provide a method for treating wastewater.

本発明者らは鋭意検討した結果、好気的直接窒素ガス化細菌を用いた廃水の処理を開放系で行うと、廃水中または大気中の雑菌が処理槽内において優先化することによって、処理槽内に硝化細菌が繁殖することがあることを突き止めた。硝化細菌が存在すると、廃水中のアンモニア態窒素が亜硝酸態窒素または硝酸態窒素に変換されてしまう。好気的直接窒素ガス化細菌はアンモニア態窒素を直接的に窒素ガス化することは可能であるが、硝酸対窒素や亜硝酸対窒素を窒素ガス化することはできない。そのため、アンモニア態窒素が亜硝酸態窒素または硝酸態窒素に変換されると、好気的条件下ではこれらを窒素ガス化できず、結果として直接的窒素ガス化反応が抑制されてしまう。
そこで、本発明者らは、好気的直接窒素ガス化細菌を用いた廃水の処理において、硝化細菌による硝化反応を抑制する硝化阻害物質を併用することで、アンモニア態窒素の亜硝酸態窒素または硝酸態窒素への変換が抑制され、直接的窒素ガス化反応が効率よく進行して窒素除去を行うことができることを見出し、本発明を完成するに至った。 As a result of diligent studies by the present inventors, when the treatment of wastewater using aerobic direct nitrogen gasifying bacteria is performed in an open system, the treatment is performed by prioritizing various bacteria in the wastewater or the atmosphere in the treatment tank. We found that nitrifying bacteria could grow in the tank. In the presence of nitrifying bacteria, ammonia nitrogen in wastewater is converted to nitrite nitrogen or nitrate nitrogen. Aerobic direct nitrogen gasification bacteria can directly gasify ammonia nitrogen, but cannot gasify nitric acid to nitrogen or nitrite to nitrogen. Therefore, when ammonia nitrogen is converted to nitrite nitrogen or nitrate nitrogen, they cannot be gasified under aerobic conditions, and as a result, the direct nitrogen gasification reaction is suppressed.
Therefore, the present inventors, in the treatment of wastewater using aerobic direct nitrogen gasifying bacteria, by using a nitrifying inhibitor that suppresses the nitrification reaction by the nitrifying bacteria in combination, nitrite nitrogen of ammonia nitrogen or We have found that the conversion to nitrate nitrogen is suppressed, the direct nitrification reaction proceeds efficiently, and nitrogen can be removed, and the present invention has been completed.

すなわち、本発明は以下の態様を有する。
［１］有機態窒素およびアンモニア態窒素の少なくとも一方を含む廃水を、好気的直接窒素ガス化細菌を用いて処理する装置であって、前記廃水を処理する処理槽と、前記廃水に好気的直接窒素ガス化細菌を添加する第一の添加手段と、前記廃水に硝化阻害物質を添加する第二の添加手段と、を備える、廃水の処理装置。
［２］前記処理槽の上流に、前記廃水を貯留する原水貯留槽をさらに備える、［１］に記載の廃水の処理装置。
［３］前記第一の添加手段が処理槽中の廃水に好気的直接窒素ガス化細菌を添加する手段であり、前記第二の添加手段が処理槽中の廃水に硝化阻害物質を添加する手段である、［１］に記載の廃水の処理装置。
［４］前記第一の添加手段が処理槽中の廃水に好気的直接窒素ガス化細菌を添加する手段であり、前記第二の添加手段が原水貯留槽中の廃水に硝化阻害物質を添加する手段である、［２］に記載の廃水の処理装置。
［５］前記好気的直接窒素ガス化細菌が、アルカリゲネス・フェカリスＮｏ４株（ＦＥＲＭＰ−２１８１４）である、［１］〜［４］のいずれか１つに記載の廃水の処理装置。
［６］前記硝化阻害物質が、チオウレア、アリルチオウレア、２−アミノ−４−クロル−６−メチルピリミジン、２−メルカプトベンゾチアゾール、ジシアンジアミド、スルファチアゾール、１−アミジノ−２−チオウレア、Ｎ−２，５−ジクロロフェニルサクシアナミド酸、４−アミノ−１，２，４−トリアゾール塩酸塩、３−メルカプト−１，２，４−トリアゾールからなる群より選ばれる１種以上である、［１］〜［５］のいずれか１つに記載の廃水の処理装置。
［７］前記硝化阻害物質が、チオウレア、アリルチオウレア、１−アミジノ−２−チオウレアからなる群より選ばれる１種以上である、［６］に記載の廃水の処理装置。 That is, the present invention has the following aspects.
[1] An apparatus for treating wastewater containing at least one of organic nitrogen and ammonia nitrogen using aerobic direct nitrogen nitrifying bacteria, wherein the treatment tank for treating the wastewater and the wastewater are aerobic. A wastewater treatment apparatus comprising a first addition means for directly adding nitrogen gasifying bacteria and a second addition means for adding a nitrification inhibitor to the wastewater.
[2] The wastewater treatment apparatus according to [1], further comprising a raw water storage tank for storing the wastewater upstream of the treatment tank.
[3] The first addition means is a means for directly adding aerobic nitrogen gasifying bacteria to the wastewater in the treatment tank, and the second addition means adds a nitrification inhibitor to the wastewater in the treatment tank. The wastewater treatment apparatus according to [1], which is a means.
[4] The first addition means is a means for directly adding aerobic nitrogen gasifying bacteria to the wastewater in the treatment tank, and the second addition means adds a nitrification inhibitor to the wastewater in the raw water storage tank. The wastewater treatment apparatus according to [2].
[5] The wastewater treatment apparatus according to any one of [1] to [4], wherein the aerobic direct nitrogen gasifying bacterium is Alcaligenes faecalis No. 4 strain (FERM P-21814).
[6] The nitrification inhibitors are thiourea, allylthiourea, 2-amino-4-chloro-6-methylpyrimidine, 2-mercaptobenzothiazole, dicyanamide, sulfathiazole, 1-amidino-2-thiourea, N-2. , 5-Dichlorophenylsuccianamide acid, 4-amino-1,2,4-triazole hydrochloride, 3-mercapto-1,2,4-triazole, which is one or more selected from the group consisting of [1] to [ 5] The wastewater treatment apparatus according to any one of.
[7] The wastewater treatment apparatus according to [6], wherein the nitrification inhibitor is at least one selected from the group consisting of thiourea, allylthiourea, and 1-amidino-2-thiourea.

［８］有機態窒素およびアンモニア態窒素の少なくとも一方を含む廃水を、好気的直接窒素ガス化細菌を用い処理槽で処理する方法であって、前記廃水に好気的直接窒素ガス化細菌を添加する第一の添加工程と、前記廃水に硝化阻害物質を添加する第二の添加工程と、を有する、廃水の処理方法。
［９］処理前の廃水を原水貯留槽に貯留しておく、［８］に記載の廃水の処理方法。
［１０］前記第一の添加工程が処理槽中の廃水に好気的直接窒素ガス化細菌を添加する工程であり、前記第二の添加工程が処理槽中の廃水に硝化阻害物質を添加する工程である、［８］に記載の廃水の処理方法。
［１１］前記第一の添加工程が処理槽中の廃水に好気的直接窒素ガス化細菌を添加する工程であり、前記第二の添加工程が原水貯留槽中の廃水に硝化阻害物質を添加する工程である、［９］に記載の廃水の処理方法。
［１２］廃水１Ｌに対して硝化阻害物質を０．３〜８０ｍｇ添加する、［８］〜［１１］のいずれか１つに記載の廃水の処理方法。
［１３］廃水１Ｌに対して硝化阻害物質を０．７５〜５５ｍｇ添加する、［１２］に記載の廃水の処理方法。
［１４］前記好気的直接窒素ガス化細菌が、アルカリゲネス・フェカリスＮｏ４株（ＦＥＲＭＰ−２１８１４）である、［８］〜［１３］のいずれか１つに記載の廃水の処理方法。
［１５］前記硝化阻害物質が、チオウレア、アリルチオウレア、２−アミノ−４−クロル−６−メチルピリミジン、２−メルカプトベンゾチアゾール、ジシアンジアミド、スルファチアゾール、１−アミジノ−２−チオウレア、Ｎ−２，５−ジクロロフェニルサクシアナミド酸、４−アミノ−１，２，４−トリアゾール塩酸塩、３−メルカプト−１，２，４−トリアゾールからなる群より選ばれる１種以上である、［８］〜［１４］のいずれか１つ項に記載の廃水の処理方法。
［１６］前記硝化阻害物質が、チオウレア、アリルチオウレア、１−アミジノ−２−チオウレアからなる群より選ばれる１種以上である、［１５］に記載の廃水の処理方法。 [8] A method of treating wastewater containing at least one of organic nitrogen and ammonia nitrogen in a treatment tank using aerobic direct nitrogen gasifying bacteria, wherein the aerobic direct nitrogen gasifying bacteria are added to the wastewater. A method for treating wastewater, which comprises a first addition step of adding and a second addition step of adding a nitrification inhibitor to the wastewater.
[9] The wastewater treatment method according to [8], wherein the wastewater before treatment is stored in a raw water storage tank.
[10] The first addition step is a step of adding aerobic direct nitrogen gasifying bacteria to the wastewater in the treatment tank, and the second addition step is a step of adding a nitrification inhibitor to the wastewater in the treatment tank. The wastewater treatment method according to [8], which is a step.
[11] The first addition step is a step of adding aerobic direct nitrogen gasifying bacteria to the wastewater in the treatment tank, and the second addition step is a step of adding a nitrification inhibitor to the wastewater in the raw water storage tank. The wastewater treatment method according to [9], which is a step of performing wastewater.
[12] The method for treating wastewater according to any one of [8] to [11], wherein 0.3 to 80 mg of a nitrification inhibitor is added to 1 L of wastewater.
[13] The method for treating wastewater according to [12], wherein 0.75 to 55 mg of a nitrification inhibitor is added to 1 L of wastewater.
[14] The method for treating wastewater according to any one of [8] to [13], wherein the aerobic direct nitrogen gasifying bacterium is Alcaligenes faecalis No. 4 strain (FERM P-21814).
[15] The nitrification inhibitors are thiourea, allylthiourea, 2-amino-4-chloro-6-methylpyrimidine, 2-mercaptobenzothiazole, dicyanamide, sulfathiazole, 1-amidino-2-thiourea, N-2. , 5-Dichlorophenylsuccianamide acid, 4-amino-1,2,4-triazole hydrochloride, 3-mercapto-1,2,4-triazole, which is one or more selected from the group consisting of [8] to [ 14] The method for treating wastewater according to any one of the items.
[16] The method for treating wastewater according to [15], wherein the nitrification inhibitor is at least one selected from the group consisting of thiourea, allylthiourea, and 1-amidino-2-thiourea.

本発明の廃水の処理装置および廃水の処理方法によれば、アンモニア態窒素を好気的に直接窒素ガス化する微生物を用いた廃水の処理を開放系で行う場合であっても、効率的に窒素除去を行うことができる。 According to the wastewater treatment apparatus and the wastewater treatment method of the present invention, even when the wastewater treatment using a microorganism that aerobically directly gasifies ammonia nitrogen into nitrogen gas is performed in an open system, it is efficient. Nitrogen removal can be performed.

本発明の廃水の処理装置の一例を示す概略構成図である。It is a schematic block diagram which shows an example of the wastewater treatment apparatus of this invention. 本発明の廃水の処理装置の他の例を示す概略構成図である。It is a schematic block diagram which shows another example of the wastewater treatment apparatus of this invention.

以下、本発明の実施形態の一例について詳細に説明するが、本発明はこれらの実施形態に限定して解釈されるものではない。
なお、本発明において、「有機体窒素」とは、有機成分に含まれる窒素のことであり、一般的にはタンパク質やアミノ酸である。
また、「硝化細菌」とは、アンモニア態窒素を亜硝酸に酸化するアンモニア酸化細菌と、亜硝酸態窒素を硝酸態窒素に酸化する亜硝酸酸化細菌との総称である。硝化細菌は独立栄養細菌であり、一般的に増殖速度が小さく、また、低温や原水中毒性物質により生育や活性が阻害されやすい。
また、「好気的直接窒素ガス化細菌」とは、好気条件下で従属栄養的にアンモニア態窒素を窒素ガス化する微生物である。また、有機体窒素をアンモニア態窒素に変換（酸化）する微生物でもある。
また、「硝化阻害物質」とは、アンモニア酸化細菌によるアンモニア酸化反応または亜硝酸酸化細菌による亜硝酸酸化反応を阻害する物質である。 Hereinafter, examples of embodiments of the present invention will be described in detail, but the present invention is not construed as being limited to these embodiments.
In the present invention, the "organic nitrogen" is nitrogen contained in an organic component, and is generally a protein or an amino acid.
Further, "nitrifying bacteria" is a general term for ammonia-oxidizing bacteria that oxidize ammonia nitrogen to nitrite and nitrite-oxidizing bacteria that oxidize nitrite nitrogen to nitrate nitrogen. Nitrifying bacteria are autotrophic bacteria, generally have a low growth rate, and their growth and activity are easily inhibited by low temperature and raw water toxic substances.
Further, the "aerobic direct nitrogen gasifying bacterium" is a microorganism that heterotrophically gasifies ammonia nitrogen under aerobic conditions. It is also a microorganism that converts (oxidizes) organic nitrogen into ammonia nitrogen.
Further, the "nitrification inhibitor" is a substance that inhibits the ammonia oxidation reaction by the ammonia-oxidizing bacteria or the nitrite oxidation reaction by the nitrite-oxidizing bacteria.

「第一実施形態」
＜廃水の処理装置＞
図１は、本発明の第一実施形態の廃水の処理装置１の概略構成図である。
この例の廃水の処理装置１は、廃水を処理する処理槽１１と、廃水に好気的直接窒素ガス化細菌を添加する第一の添加手段１２と、廃水に硝化阻害物質を添加する第二の添加手段１３と、処理された廃水（処理水）を貯留する処理水貯留槽１４とを備える。
なお、本発明において処理前の廃水を「原水」ともいい、処理後の廃水を「処理水」ともいう。 "First embodiment"
<Wastewater treatment equipment>
FIG. 1 is a schematic configuration diagram of the wastewater treatment apparatus 1 according to the first embodiment of the present invention.
The wastewater treatment apparatus 1 of this example includes a treatment tank 11 for treating wastewater, a first addition means 12 for adding aerobic direct nitrogen gasifying bacteria to wastewater, and a second addition means for adding a nitrification inhibitor to wastewater. The addition means 13 and the treated water storage tank 14 for storing the treated wastewater (treated water) are provided.
In the present invention, the wastewater before treatment is also referred to as "raw water", and the wastewater after treatment is also referred to as "treated water".

（廃水）
本発明の処理対象となる廃水は、工場、事業所等から排出される被処理水であり、有機態窒素およびアンモニア態窒素の少なくとも一方を含む。
有機体窒素は、嫌気条件または好気条件下において微生物の作用により、アンモニア態窒素に変換される。有機体窒素を多く含む廃水として、食品廃水、畜産廃水などが挙げられる。
有機体窒素以外の窒素成分としては、アンモニア態窒素、硝酸態窒素、亜硝酸態窒素などの無機体窒素がある。 (Wastewater)
The wastewater to be treated in the present invention is water to be treated discharged from factories, business establishments, etc., and includes at least one of organic nitrogen and ammonia nitrogen.
Organic nitrogen is converted to ammonia nitrogen by the action of microorganisms under anaerobic or aerobic conditions. Examples of wastewater containing a large amount of organic nitrogen include food wastewater and livestock wastewater.
Nitrogen components other than organic nitrogen include inorganic nitrogen such as ammonia nitrogen, nitrate nitrogen, and nitrite nitrogen.

（処理槽）
処理槽１１は、生物学的廃水処理を行うために微生物（活性汚泥）を充填するものであり、本実施形態においては好気的直接窒素ガス化細菌を含む。
処理槽１１には、第一の廃水流路１５と処理水流路１６が接続されている。第一の廃水流路１５は、工場や事業所等から排出された廃水を処理槽１１に流入させるための流路である。一方、処理水流路１６は、処理槽１１か排出された処理水を後述の処理水貯留槽１４に流入させるための流路である。
また、処理槽１１内には槽内を好気条件に維持するために散気装置１７が設置されている。散気装置１７としては、ブロア１７ａより送気された空気を処理槽１１内に散気できるものであれば特に限定されない。 (Processing tank)
The treatment tank 11 is filled with microorganisms (activated sludge) for biological wastewater treatment, and contains aerobic direct nitrogen gasifying bacteria in the present embodiment.
The first wastewater flow path 15 and the treatment water flow path 16 are connected to the treatment tank 11. The first wastewater flow path 15 is a flow path for allowing wastewater discharged from a factory, a business establishment, or the like to flow into the treatment tank 11. On the other hand, the treated water flow path 16 is a flow path for allowing the treated water discharged from the treatment tank 11 to flow into the treated water storage tank 14 described later.
Further, an air diffuser 17 is installed in the processing tank 11 in order to maintain the inside of the tank under aerobic conditions. The air diffuser 17 is not particularly limited as long as the air supplied from the blower 17a can be diffused into the processing tank 11.

処理槽１１には、槽内のｐＨ、酸化還元電位、水温、アンモニア濃度を測定する各種測定機器（いずれも図示略）を設置することが好ましい。
特に生物反応においてｐＨ制御は重要であり、槽内のｐＨが酸性化またはアルカリ化した場合には、アルカリ溶液または酸性溶液を添加するための装置（いずれも図示略）をさらに設置し、槽内のｐＨに応じてアルカリ溶液または酸性溶液を処理槽１１に添加することが好ましい。 It is preferable to install various measuring instruments (all not shown) for measuring the pH, redox potential, water temperature, and ammonia concentration in the treatment tank 11.
In particular, pH control is important in biological reactions, and when the pH in the tank is acidified or alkalized, a device for adding an alkaline solution or an acidic solution (both not shown) is further installed in the tank. It is preferable to add an alkaline solution or an acidic solution to the treatment tank 11 depending on the pH of.

（第一の添加手段）
第一の添加手段１２は、廃水に好気的直接窒素ガス化細菌を添加するものである。
この例の第一の添加手段１２は、処理槽１１の廃水に好気的直接窒素ガス化細菌を添加する。
第一の添加手段１２は、好気的直接窒素ガス化細菌を貯留する第一のタンク１２ａと、好気的直接窒素ガス化細菌を第一のタンク１２ａから廃水に供給する第一の供給流路１２ｂと、好気的直接窒素ガス化細菌を送り出す第一のポンプ１２ｃとを備える。
第一のタンク１２ａには、タンク内温度を適温に維持できるように、加温または冷却機構が備えられていることが好ましい。タンク内温度は０〜１５℃が好ましい。 (First addition means)
The first addition means 12 is for adding aerobic direct nitrogen gasifying bacteria to wastewater.
The first addition means 12 of this example adds aerobic direct nitrogen gasifying bacteria to the wastewater of the treatment tank 11.
The first addition means 12 includes a first tank 12a for storing aerobic direct nitrogen gasifying bacteria and a first supply stream for supplying aerobic direct nitrogen gasifying bacteria from the first tank 12a to waste water. It comprises a passage 12b and a first pump 12c that delivers aerobic direct nitrogen gasifying bacteria.
The first tank 12a is preferably provided with a heating or cooling mechanism so that the temperature inside the tank can be maintained at an appropriate temperature. The temperature inside the tank is preferably 0 to 15 ° C.

好気的直接窒素ガス化細菌としては、例えば、アルカリゲネス・フェカリスＮｏ４株（ＦＥＲＭＰ−２１８１４）、アルカリゲネス・フェカリスＯＫＫ１７株などの菌株が挙げられる。これらの中でも、アルカリゲネス・フェカリスＮｏ４株（ＦＥＲＭＰ−２１８１４）が好ましい。アルカリゲネス・フェカリスＮｏ４株（ＦＥＲＭＰ−２１８１４）は、最大アンモニア除去速度が２９ｍｇＮ／Ｌ／ｈｒであり、他の好気的直接窒素ガス化細菌と比較して非常に高い窒素除去性能を有している。 Examples of the aerobic direct nitrogen gasifying bacterium include strains such as Alcaligenes faecalis No. 4 strain (FERM P-21814) and Alcaligenes faecalis OKK17 strain. Among these, Alcaligenes faecalis No. 4 strain (FERM P-21814) is preferable. Alcaligenes faecalis No. 4 strain (FERM P-21814) has a maximum ammonia removal rate of 29 mgN / L / hr and has extremely high nitrogen removal performance as compared with other aerobic direct nitrogen gasifying bacteria. There is.

（第二の添加手段）
第二の添加手段１３は、廃水に硝化阻害物質を添加するものである。
この例の第二の添加手段１３は、処理槽１１の廃水に硝化阻害物質を添加する。
第二の添加手段１３は、硝化阻害物質の溶液を貯留する第二のタンク１３ａと、硝化阻害物質の溶液を第二のタンク１３ａから廃水に供給する第二の供給流路１３ｂと、硝化阻害物質の溶液を送り出す第二のポンプ１３ｃとを備える。
なお、硝化阻害物質が粉体である場合は、第二のタンク１３ａ、第二の供給流路１３ｂおよび第二のポンプ１３ｃに代えて、粉体状の硝化阻害物質を貯留する容器と、粉体投入用設備とを組合せて用いてもよい。 (Second addition means)
The second addition means 13 is for adding a nitrification inhibitor to wastewater.
The second addition means 13 of this example adds a nitrification inhibitor to the wastewater of the treatment tank 11.
The second addition means 13 includes a second tank 13a for storing a solution of the nitrification inhibitor, a second supply channel 13b for supplying the solution of the nitrification inhibitor to the wastewater from the second tank 13a, and an inhibition of nitrification. It is provided with a second pump 13c that delivers a solution of the substance.
When the nitrification inhibitor is powder, instead of the second tank 13a, the second supply flow path 13b, and the second pump 13c, a container for storing the powdery nitrification inhibitor and powder. It may be used in combination with the equipment for putting into the body.

硝化阻害物質としては、銅や亜鉛等の重金属類、シアンやフェノール等の化学物質などが挙げられる。これら硝化阻害物質は、硝化細菌以外にも活性汚泥を構成する多くの微生物に対しても活性を阻害することがある。
硝化阻害物質の中でも、消化反応を特異的に阻害できる点で、チオウレア、アリルチオウレア、２−アミノ−４−クロル−６−メチルピリミジン、２−メルカプトベンゾチアゾール、ジシアンジアミド、スルファチアゾール、１−アミジノ−２−チオウレア、Ｎ−２，５−ジクロロフェニルサクシアナミド酸、４−アミノ−１，２，４−トリアゾール塩酸塩、３−メルカプト−１，２，４−トリアゾールが好ましい。これらは１種を単独で用いてもよいし、２種以上を併用してもよい。
これらの中でも、安価であり、かつ硝化細菌以外の微生物への影響が少ない点で、チオウレア、アリルチオウレア、１−アミジノ−２−チオウレアが特に好ましい。例えば、アリルチオウレアは、アンモニア酸化細菌の呼吸代謝経路に関するアンモニアモノオキシゲナーゼを阻害することによって、硝化を阻害する。 Examples of the nitrification inhibitor include heavy metals such as copper and zinc, and chemical substances such as cyanide and phenol. These nitrifying inhibitors may inhibit the activity of many microorganisms constituting activated sludge in addition to nitrifying bacteria.
Among the nitrification inhibitors, thiourea, allylthiourea, 2-amino-4-chloro-6-methylpyrimidine, 2-mercaptobenzothiazole, dicyanamide, sulfathiazole, 1-amidino in that they can specifically inhibit the digestive reaction. -2-thiourea, N-2,5-dichlorophenylsuccianamide acid, 4-amino-1,2,4-triazole hydrochloride and 3-mercapto-1,2,4-triazole are preferred. One of these may be used alone, or two or more thereof may be used in combination.
Among these, thiourea, allyl thiourea, and 1-amidino-2-thiourea are particularly preferable because they are inexpensive and have little effect on microorganisms other than nitrifying bacteria. For example, allylthiourea inhibits nitrification by inhibiting ammonia monooxygenase in the respiratory metabolic pathway of ammonia-oxidizing bacteria.

（処理水貯留槽）
処理水貯留槽１４は、処理後の廃水（処理水）を貯留するものである。
処理水貯留槽１４には、処理水流路１６が接続され、処理槽１１か排出された処理水が流入される。 (Treatment water storage tank)
The treated water storage tank 14 stores the treated wastewater (treated water).
A treated water flow path 16 is connected to the treated water storage tank 14, and the treated water discharged from the treated water tank 11 flows into the treated water storage tank 14.

＜廃水の処理方法＞
図１に示す廃水の処理装置１を用いた廃水の処理方法では、まず、工場や事業所等から排出された廃水を第一の廃水流路１５を介して処理槽１１へ流入させる。次いで、処理槽１１中の廃水に第一の添加手段１２から好気的直接窒素ガス化細菌を添加し（第一の添加工程）、処理槽１１中の廃水に第二の添加手段１３から硝化阻害物質を添加する（第二の添加工程）。処理槽１１内の散気装置１７を作動させ、槽内を好気条件に維持し、生物学的廃水処理を行う。すると、廃水中のアンモニア態窒素が好気的直接窒素ガス化細菌によって窒素ガス化し、廃水から窒素が除去される。なお、廃水中に有機態窒素が含まれている場合、上述したように、有機態窒素は微生物の作用によりアンモニア態窒素に変換された後に、好気的直接窒素ガス化細菌によって窒素ガス化される。
処理された廃水は、処理水として処理槽１１から処理水流路１６を介して処理水貯留槽１４へ供給され、貯留される。 <Wastewater treatment method>
In the wastewater treatment method using the wastewater treatment device 1 shown in FIG. 1, first, the wastewater discharged from a factory, a business establishment, or the like is made to flow into the treatment tank 11 through the first wastewater flow path 15. Next, aerobic direct nitrogen gasifying bacteria are added to the wastewater in the treatment tank 11 from the first addition means 12 (first addition step), and the wastewater in the treatment tank 11 is nitrified from the second addition means 13. Inhibitor is added (second addition step). The air diffuser 17 in the treatment tank 11 is operated to maintain the inside of the tank under aerobic conditions, and biological wastewater treatment is performed. Then, the ammonia nitrogen in the wastewater is gasified by aerobic direct nitrogen gasifying bacteria, and nitrogen is removed from the wastewater. When organic nitrogen is contained in wastewater, as described above, organic nitrogen is converted to ammonia nitrogen by the action of microorganisms, and then nitrogen gasified by aerobic direct nitrogen gasification bacteria. To.
The treated wastewater is supplied as treated water from the treatment tank 11 to the treated water storage tank 14 via the treated water flow path 16 and stored.

第一の添加工程と第二の添加工程は、同時に行ってもよいし、第一の添加工程の後に第二の添加工程を行ってもよいし、第二の添加工程の後に第一の添加工程を行ってもよい。
特に、第一の添加工程と第二の添加工程を同時に行うか、第二の添加工程の後に第一の添加工程を行うことが好ましい。 The first addition step and the second addition step may be carried out at the same time, the second addition step may be carried out after the first addition step, or the first addition may be carried out after the second addition step. The process may be performed.
In particular, it is preferable to carry out the first addition step and the second addition step at the same time, or to carry out the first addition step after the second addition step.

好気的直接窒素ガス化細菌の添加量は、窒素除去性能や菌体沈降分離等の観点から、処理槽１１中の乾燥重量濃度が、２０００〜２００００ｍｇ／Ｌとなる量が好ましい。 The amount of the aerobic direct nitrogen gasified bacteria added is preferably an amount such that the dry weight concentration in the treatment tank 11 is 2000 to 20000 mg / L from the viewpoint of nitrogen removal performance, cell sedimentation and separation, and the like.

硝化阻害物質の添加量は、廃水１Ｌに対して０．３〜８０ｍｇが好ましく、０．５〜７５ｍｇがより好ましく、０．７５〜５５ｍｇが更に好ましく、１〜５０ｍｇが特に好ましい。
上述したように、硝化細菌の作用によりアンモニア態窒素が亜硝酸態窒素または硝酸態窒素に変換されると、好気的直接窒素ガス化細菌ではこれらを直接脱窒することが困難であり、窒素除去率が低下する。
硝化阻害物質の添加量が０．３ｍｇ／Ｌ以上であれば、硝化反応を十分に抑制できるので、窒素除去率の低下を抑制できる。
ただし、硝化阻害物質の添加量が過剰になると、好気的直接窒素ガス化細菌による有機物酸化や窒素ガス化が阻害されるおそれがある。また、好気的直接窒素ガス化細菌以外の従属栄養細菌（他の従属栄養細菌）による有機物酸化も阻害されるおそれがある。その結果、窒素除去率が低下することがある。
硝化阻害物質の添加量が８０ｍｇ／Ｌ以下であれば、好気的直接窒素ガス化細菌や他の従属栄養細菌への影響が少なく、窒素除去率を良好に維持できる。 The amount of the nitrification inhibitor added is preferably 0.3 to 80 mg, more preferably 0.5 to 75 mg, further preferably 0.75 to 55 mg, and particularly preferably 1 to 50 mg with respect to 1 L of wastewater.
As described above, when ammonia nitrogen is converted to nitrite nitrogen or nitrate nitrogen by the action of nitrifying bacteria, it is difficult for aerobic direct nitrogen gasifying bacteria to directly denitrify them, and nitrogen. The removal rate decreases.
When the amount of the nitrification inhibitor added is 0.3 mg / L or more, the nitrification reaction can be sufficiently suppressed, so that a decrease in the nitrogen removal rate can be suppressed.
However, if the amount of the nitrification inhibitor added is excessive, there is a risk that organic matter oxidation and nitrogen gasification by aerobic direct nitrogen gasification bacteria will be inhibited. In addition, organic matter oxidation by heterotrophic bacteria (other heterotrophic bacteria) other than aerobic direct nitrogen gasification bacteria may be inhibited. As a result, the nitrogen removal rate may decrease.
When the amount of the nitrification inhibitor added is 80 mg / L or less, the effect on aerobic direct nitrogen gasifying bacteria and other heterotrophic bacteria is small, and the nitrogen removal rate can be maintained well.

＜作用効果＞
以上説明した本発明の第一実施形態の廃水の処理装置および廃水の処理方法によれば、好気的直接窒素ガス化細菌を用いた廃水の処理において、硝化細菌による硝化反応を抑制する硝化阻害物質を併用することで、アンモニア態窒素の亜硝酸態窒素または硝酸態窒素への変換が抑制され、直接的窒素ガス化反応が効率よく進行して窒素除去を行うことができる。よって、廃水の処理を開放系で行っても、効率的に窒素除去を行うことができる。 <Effect>
According to the wastewater treatment apparatus and wastewater treatment method of the first embodiment of the present invention described above, nitrification inhibition that suppresses the nitrification reaction by nitrifying bacteria in the treatment of wastewater using aerobic direct nitrogen gasifying bacteria. By using the substance in combination, the conversion of ammonia nitrogen to nitrite nitrogen or nitrate nitrogen is suppressed, and the direct nitrification reaction proceeds efficiently to remove nitrogen. Therefore, even if the wastewater is treated in an open system, nitrogen can be efficiently removed.

「第二の実施形態」
＜廃水の処理装置＞
図２は、本発明の第二実施形態の廃水の処理装置２の概略構成図である。
この例の廃水の処理装置２は、廃水を貯留する原水貯留槽１８と、廃水を処理する処理槽１１と、廃水に好気的直接窒素ガス化細菌を添加する第一の添加手段１２と、廃水に硝化阻害物質を添加する第二の添加手段１３と、処理された廃水（処理水）を貯留する処理水貯留槽１４とを備える。 "Second embodiment"
<Wastewater treatment equipment>
FIG. 2 is a schematic configuration diagram of the wastewater treatment device 2 according to the second embodiment of the present invention.
The wastewater treatment device 2 of this example includes a raw water storage tank 18 for storing wastewater, a treatment tank 11 for treating wastewater, and a first addition means 12 for directly adding aerobic direct nitrogen gasifying bacteria to wastewater. It is provided with a second addition means 13 for adding a nitrification inhibitor to the wastewater, and a treated water storage tank 14 for storing the treated wastewater (treated water).

（原水貯留槽）
原水貯留槽１８は、廃水を処理前に一旦貯留するためのものであり、原水水量または原水水質の変動を均一化することを目的にして設置される。
原水貯留槽１８には、第二の廃水流路１９と第三の廃水流路２１が接続されている。第二の廃水流路１９は、工場や事業所等から排出された廃水を原水貯留槽１８に流入させるための流路である。一方、第三の廃水流路２１は、原水貯留槽１８か排出された廃水（原水）を処理槽１１に流入させるための流路である。
また、この例の原水貯留槽１８内には、原水水質を均一化するために撹拌機１８ａが設置されている。 (Raw water storage tank)
The raw water storage tank 18 is for temporarily storing wastewater before treatment, and is installed for the purpose of equalizing fluctuations in the amount of raw water or the quality of raw water.
A second wastewater flow path 19 and a third wastewater flow path 21 are connected to the raw water storage tank 18. The second wastewater flow path 19 is a flow path for allowing the wastewater discharged from the factory, business establishment, or the like to flow into the raw water storage tank 18. On the other hand, the third wastewater flow path 21 is a flow path for allowing the wastewater (raw water) discharged from the raw water storage tank 18 to flow into the treatment tank 11.
Further, in the raw water storage tank 18 of this example, a stirrer 18a is installed in order to make the raw water quality uniform.

（処理槽）
本実施形態の処理槽１１は、第一の廃水流路１５の代わりに第三の廃水流路２１が接続されている点以外は、第一実施形態の処理槽１１と同じである。 (Processing tank)
The treatment tank 11 of the present embodiment is the same as the treatment tank 11 of the first embodiment except that a third wastewater flow path 21 is connected instead of the first wastewater flow path 15.

（第一の添加手段）
本実施形態の第一の添加手段１２は、第一実施形態の第一の添加手段１２と同じである。 (First addition means)
The first addition means 12 of the present embodiment is the same as the first addition means 12 of the first embodiment.

（第二の添加手段）
本実施形態の第二の添加手段１３は、原水貯留槽１８の廃水に硝化阻害物質を添加する以外は、第一実施形態の第二の添加手段１３と同じである。 (Second addition means)
The second addition means 13 of the present embodiment is the same as the second addition means 13 of the first embodiment except that the nitrification inhibitor is added to the wastewater of the raw water storage tank 18.

（処理水貯留槽）
本実施形態の処理水貯留槽１４は、第一実施形態の処理水貯留槽１４と同じである。 (Treatment water storage tank)
The treated water storage tank 14 of the present embodiment is the same as the treated water storage tank 14 of the first embodiment.

＜廃水の処理方法＞
図２に示す廃水の処理装置２を用いた廃水の処理方法では、まず、工場や事業所等から排出された廃水を第二の廃水流路１９を介して原水貯留槽１８へ流入させ、貯留する。次いで、原水貯留槽１８中の廃水に第二の添加手段１３から硝化阻害物質を添加し（第二の添加工程）、撹拌機１８ａにて廃水を撹拌する。次いで、硝化阻害物質が添加された廃水を原水貯留槽１８から第三の廃水流路２１を介して処理槽１１へ流入させる。次いで、処理槽１１中の廃水に第一の添加手段１２から好気的直接窒素ガス化細菌を添加する（第一の添加工程）。処理槽１１内の散気装置１７を作動させ、槽内を好気条件に維持し、生物学的廃水処理を行う。すると、廃水中のアンモニア態窒素が好気的直接窒素ガス化細菌によって窒素ガス化し、廃水から窒素が除去される。なお、廃水中に有機態窒素が含まれている場合、上述したように、有機態窒素は微生物の作用によりアンモニア態窒素に変換された後に、好気的直接窒素ガス化細菌によって窒素ガス化される。
処理された廃水は、処理水として処理槽１１から処理水流路１６を介して処理水貯留槽１４へ供給され、貯留される。 <Wastewater treatment method>
In the wastewater treatment method using the wastewater treatment device 2 shown in FIG. 2, first, the wastewater discharged from a factory, a business establishment, or the like is flowed into the raw water storage tank 18 through the second wastewater flow path 19 and stored. To do. Next, a nitrification inhibitor is added to the wastewater in the raw water storage tank 18 from the second addition means 13 (second addition step), and the wastewater is agitated by the stirrer 18a. Next, the wastewater to which the nitrification inhibitor is added flows from the raw water storage tank 18 into the treatment tank 11 via the third wastewater flow path 21. Next, aerobic direct nitrogen gasifying bacteria are added to the wastewater in the treatment tank 11 from the first addition means 12 (first addition step). The air diffuser 17 in the treatment tank 11 is operated to maintain the inside of the tank under aerobic conditions, and biological wastewater treatment is performed. Then, the ammonia nitrogen in the wastewater is gasified by aerobic direct nitrogen gasifying bacteria, and nitrogen is removed from the wastewater. When organic nitrogen is contained in wastewater, as described above, organic nitrogen is converted to ammonia nitrogen by the action of microorganisms, and then nitrogen gasified by aerobic direct nitrogen gasification bacteria. To.
The treated wastewater is supplied as treated water from the treatment tank 11 to the treated water storage tank 14 via the treated water flow path 16 and stored.

好気的直接窒素ガス化細菌の添加量および硝化阻害物質の添加量は、第一実施形態の廃水の処理方法と同じである。 The amount of the aerobic direct nitrogen gasifying bacterium added and the amount of the nitrification inhibitor added are the same as those of the wastewater treatment method of the first embodiment.

＜作用効果＞
以上説明した本発明の第二実施形態の廃水の処理装置および廃水の処理方法によれば、好気的直接窒素ガス化細菌を用いた廃水の処理において、硝化細菌による硝化反応を抑制する硝化阻害物質を併用することで、アンモニア態窒素の亜硝酸態窒素または硝酸態窒素への変換が抑制され、直接的窒素ガス化反応が効率よく進行して窒素除去を行うことができる。よって、廃水の処理を開放系で行っても、効率的に窒素除去を行うことができる。また、第二実施形態の廃水の処理装置および廃水の処理方法では、廃水を処理前に一旦、原水貯留槽に貯留するが、硝化阻害物質を原水貯留槽中の廃水に添加するので、原水貯留槽での廃水の貯留を開放系で行っても、アンモニア態窒素の亜硝酸態窒素または硝酸態窒素への変換を抑制できる。 <Effect>
According to the wastewater treatment apparatus and the wastewater treatment method of the second embodiment of the present invention described above, nitrification inhibition that suppresses the nitrification reaction by nitrifying bacteria in the treatment of wastewater using aerobic direct nitrogen gasifying bacteria. By using the substance in combination, the conversion of ammonia nitrogen to nitrite nitrogen or nitrate nitrogen is suppressed, and the direct nitrification reaction proceeds efficiently to remove nitrogen. Therefore, even if the wastewater is treated in an open system, nitrogen can be efficiently removed. Further, in the wastewater treatment apparatus and the wastewater treatment method of the second embodiment, the wastewater is temporarily stored in the raw water storage tank before the treatment, but since the nitrification inhibitor is added to the wastewater in the raw water storage tank, the raw water is stored. Even if the wastewater is stored in the tank in an open system, the conversion of ammonia nitrogen to nitrite nitrogen or nitrate nitrogen can be suppressed.

「他の実施形態」
本発明の廃水の処理装置および廃水の処理方法は、上述した実施形態に限定されない。例えば、第一実施形態において、好気的直接窒素ガス化細菌および硝化阻害物質は、第一の廃水流路１５を流れる廃水に添加されてもよいし、硝化阻害物質が第一の廃水流路１５を流れる廃水に添加され、好気的直接窒素ガス化細菌が処理槽中の廃水に添加されてもよい。また、好気的直接窒素ガス化細菌が第一の廃水流路１５を流れる廃水に添加され、硝化阻害物質が処理槽中の廃水に添加されてもよい。
また、第一実施形態において、処理槽１１の上流に原水貯留槽が設けられていてもよい。ただし、この場合、原水貯留槽での廃水の貯留は閉鎖系で行うことが好ましい。 "Other embodiments"
The wastewater treatment apparatus and the wastewater treatment method of the present invention are not limited to the above-described embodiments. For example, in the first embodiment, the aerobic direct nitrogen gasifying bacteria and the nitrification inhibitor may be added to the wastewater flowing through the first wastewater channel 15, and the nitrification inhibitor may be added to the first wastewater channel. It may be added to the wastewater flowing through 15, and aerobic direct nitrogen nitrifying bacteria may be added to the wastewater in the treatment tank. Further, aerobic direct nitrogen gasifying bacteria may be added to the wastewater flowing through the first wastewater flow path 15, and a nitrification inhibitor may be added to the wastewater in the treatment tank.
Further, in the first embodiment, a raw water storage tank may be provided upstream of the treatment tank 11. However, in this case, it is preferable to store the wastewater in the raw water storage tank in a closed system.

また、第二実施形態において、硝化阻害物質は第二の廃水流路１９を流れる廃水に添加されてもよい。好気的直接窒素ガス化細菌は第三の廃水流路２１を流れる廃水に添加されてもよいし、原水貯留槽１８中の廃水に添加されてもよい。 Further, in the second embodiment, the nitrification inhibitor may be added to the wastewater flowing through the second wastewater flow path 19. The aerobic direct nitrogen gasifying bacteria may be added to the wastewater flowing through the third wastewater flow path 21, or may be added to the wastewater in the raw water storage tank 18.

以下、本発明を実施例により具体的に説明するが、本発明はこれらに限定されるものではない。 Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

「実施例１」
アルカリゲネスの純水培養液を初発汚泥として処理槽に添加し、以下のようにして開放系で廃水の処理を行った。なお、雑菌混入などによりアルカリゲネス・フェカリスＮｏ４株（ＦＥＲＭＰ−２１８１４）の存在割合が５０％となった場合を想定した。
まず、アルカリゲネス・フェカリスＮｏ４株（ＦＥＲＭＰ−２１８１４）の培養液を菌体乾燥重量濃度として２，０００ｍｇ／Ｌとなるように菌体懸濁液を調製した。
別途、生活排水を処理している標準活性汚泥設備から標準活性汚泥を採取し、乾燥重量濃度として２，０００ｍｇ／Ｌとなるように汚泥懸濁液を調製した。
１０００ｍＬ容積の三角フラスコに、前記菌体懸濁液と前記汚泥懸濁液とをそれぞれ１００ｍＬ投入して混合し、懸濁混合液を得た。
得られた懸濁混合液に対して、硫酸アンモニウムをアンモニア態窒素として５００ｍｇ／Ｌ、酢酸ナトリウムを３，０００ｍｇ／Ｌとなるように添加し、さらに硫酸溶液または水酸化ナトリウム溶液を用いてｐＨを６．８〜７．２の範囲に調整した。
引き続き、ｐＨ調整後の懸濁混合液に対して、硝化阻害物質としてアリルチオウレアを０．１ｍｇ／Ｌとなるように添加し、２５℃で盪とう培養（盪とう速度１２０ｒｐｍ）を行なった。
培養直後（初期）および２４時間後に懸濁混合液を採取し、０．４５μｍのディスクフィルターでろ過し、ろ過液を収集して、全窒素濃度および全有機体炭素濃度を以下のようにして測定し、下記式（１）より全窒素除去率を求め、下記式（２）より全有機体炭素除去率を求めた。また、４８時間後のろ過液中の硝酸態窒素濃度を以下のようにして測定した。これらの結果を表１に示す。
全窒素除去率（％）＝（初期の全窒素濃度−２４時間後の全窒素濃度）／初期の全窒素濃度×１００・・・（１）
全有機体炭素除去率（％）＝（初期の全有機体炭素濃度−２４時間後の全有機体炭素濃度）／初期の全有機体炭素濃度×１００・・・（２）
なお、酢酸ナトリウム３，０００ｍｇ／Ｌ溶液の全有機体炭素濃度（初期の全有機体炭素濃度）を測定した結果、全有機体炭素濃度は８７０ｍｇ／Ｌであった。 "Example 1"
Alcaligenes pure water culture solution was added to the treatment tank as the first sludge, and the wastewater was treated in an open system as follows. It is assumed that the abundance ratio of Alcaligenes faecalis No. 4 strain (FERM P-21814) is 50% due to contamination with various germs.
First, a cell suspension was prepared so that the culture solution of Alcaligenes faecalis No. 4 strain (FERM P-21814) had a dry weight concentration of cells of 2,000 mg / L.
Separately, standard activated sludge was collected from a standard activated sludge facility treating domestic wastewater, and a sludge suspension was prepared so that the dry weight concentration was 2,000 mg / L.
100 mL each of the cell suspension and the sludge suspension was put into a 1000 mL volume Erlenmeyer flask and mixed to obtain a suspension mixture.
To the obtained suspension mixture, ammonium sulfate was added as ammonia nitrogen at 500 mg / L and sodium acetate was added at 3,000 mg / L, and the pH was further adjusted to 6 using a sulfuric acid solution or a sodium hydroxide solution. Adjusted to the range of .8 to 7.2.
Subsequently, allylthiourea as a nitrification inhibitor was added to the pH-adjusted suspension mixture so as to be 0.1 mg / L, and ablation culture (abrasion speed 120 rpm) was carried out at 25 ° C.
Immediately after culturing (initial) and 24 hours later, the suspension mixture is collected, filtered through a 0.45 μm disk filter, the filtrate is collected, and the total nitrogen concentration and total organic carbon concentration are measured as follows. Then, the total nitrogen removal rate was obtained from the following formula (1), and the total organic carbon removal rate was obtained from the following formula (2). Moreover, the nitrate nitrogen concentration in the filtrate after 48 hours was measured as follows. These results are shown in Table 1.
Total nitrogen removal rate (%) = (Initial total nitrogen concentration-24 hours later total nitrogen concentration) / Initial total nitrogen concentration x 100 ... (1)
Total organic carbon removal rate (%) = (Initial total organic carbon concentration-24 hours later total organic carbon concentration) / Initial total organic carbon concentration x 100 ... (2)
As a result of measuring the total organic carbon concentration (initial total organic carbon concentration) of the sodium acetate 3,000 mg / L solution, the total organic carbon concentration was 870 mg / L.

（全有機体炭素濃度の測定）
全有機体炭素濃度は、全有機体炭素分析装置（株式会社三菱化学アナリテック製、「ＴＯＣ−３００Ｖ」）を用いて測定した。本装置の測定方式は、燃焼触媒酸化／ＮＤＩＲ検出とした。 (Measurement of total organic carbon concentration)
The total organic carbon concentration was measured using an total organic carbon analyzer (“TOC-300V” manufactured by Mitsubishi Chemical Analytech Co., Ltd.). The measurement method of this device was combustion catalyst oxidation / NDIR detection.

（全窒素濃度の測定）
全窒素濃度は、前記の全有機体炭素分析装置（ＴＯＣ−３００Ｖ）の後段に接続した、窒素検出器（株式会社三菱化学アナリテック製、「ＮＤ−２１０型」）を用いて測定した。本装置の測定方法は、酸化分解−化学発光法（減圧法）とした。 (Measurement of total nitrogen concentration)
The total nitrogen concentration was measured using a nitrogen detector (manufactured by Mitsubishi Chemical Analytech Co., Ltd., "ND-210 type") connected to the subsequent stage of the total organic carbon analyzer (TOC-300V). The measurement method of this device was the oxidative decomposition-chemiluminescence method (decompression method).

（硝酸態窒素濃度の測定）
硝酸態窒素濃度は、簡易水分析装置（ＨＡＣＨ社製、「ＤＲ−２７００」）を用いて測定した。測定用試薬としては、硝酸塩測定試薬パウダーピローＮｉｔｒａＶｅｒ５（Ｃａｔ．Ｎｏ２１０６１−６９）を用いた。 (Measurement of nitrate nitrogen concentration)
The nitrate nitrogen concentration was measured using a simple water analyzer ("DR-2700" manufactured by HACH). As the measurement reagent, a nitrate measurement reagent powder pillow Nitra Ver5 (Cat. No21061-69) was used.

「実施例２〜７、比較例１」
アリルチオウレアの添加量を表１に示すように変更した以外は、実施例１と同様にして廃水の処理を行い、全窒素除去率、全有機体炭素除去率および硝酸態窒素濃度を測定した。結果を表１に示す。 "Examples 2 to 7, Comparative Example 1"
Wastewater was treated in the same manner as in Example 1 except that the amount of allylthiourea added was changed as shown in Table 1, and the total nitrogen removal rate, the total organic carbon removal rate, and the nitrate nitrogen concentration were measured. The results are shown in Table 1.

「実施例８〜１４、比較例２」
硝化阻害物質として硝化阻害抑制剤（三菱レイヨン株式会社製、「ノンライザー（ＮＯＮＲＩＳＥＲ）」を用い、ノンライザーの添加量を表２に示すように変更した以外は、実施例１と同様にして廃水の処理を行い、全窒素除去率、全有機体炭素除去率および硝酸態窒素濃度を測定した。結果を表２に示す。
なお、ノンライザーは、ＴＯＣ分析値から計算した結果、硝化阻害物質である１−アミジノ−２−チオウレアを総質量に対して９５質量％含んでいた。 "Examples 8 to 14, Comparative Example 2"
Wastewater was used in the same manner as in Example 1 except that a nitrification inhibitor (manufactured by Mitsubishi Rayon Co., Ltd., "NONRISER") was used as a nitrification inhibitor and the amount of non-riser added was changed as shown in Table 2. The total nitrogen removal rate, the total organic carbon removal rate, and the nitrate nitrogen concentration were measured. The results are shown in Table 2.
As a result of calculation from the TOC analysis value, the non-riser contained 95% by mass of 1-amidine-2-thiourea, which is a nitrification inhibitor, with respect to the total mass.

実施例１〜７は、比較例１に比べて全窒素除去率が高かった。また、４８時間後のろ過液中の硝酸態窒素濃度が低く、アンモニアの硝化が抑制されていた。特に、アリルチオウレアを０．５ｍｇ／Ｌ以上添加した実施例２〜７は、全窒素除去率がより高く、硝酸態窒素濃度がより低かった。 Examples 1 to 7 had a higher total nitrogen removal rate than Comparative Example 1. In addition, the concentration of nitrate nitrogen in the filtrate after 48 hours was low, and nitrification of ammonia was suppressed. In particular, in Examples 2 to 7 to which 0.5 mg / L or more of allylthiourea was added, the total nitrogen removal rate was higher and the nitrate nitrogen concentration was lower.

実施例８〜１４は、比較例２に比べて全窒素除去率が高かった。また、４８時間後のろ過液中の硝酸態窒素濃度が低く、アンモニアの硝化が抑制されていた。特に、ノンライザーを０．５ｍｇ／Ｌ以上添加した実施例９〜１４は、全窒素除去率がより高く、硝酸態窒素濃度がより低かった。 Examples 8 to 14 had a higher total nitrogen removal rate than Comparative Example 2. In addition, the concentration of nitrate nitrogen in the filtrate after 48 hours was low, and nitrification of ammonia was suppressed. In particular, in Examples 9 to 14 in which 0.5 mg / L or more of the non-riser was added, the total nitrogen removal rate was higher and the nitrate nitrogen concentration was lower.

１廃水の処理装置
２廃水の処理装置
１１処理槽
１２第一の添加手段
１２ａ第一のタンク
１２ｂ第一の供給流路
１２ｃ第一のポンプ
１３第二の添加手段
１３ａ第二のタンク
１３ｂ第二の供給流路
１３ｃ第二のポンプ
１４処理水貯留槽
１５第一の廃水流路
１６処理水流路
１７散気装置
１７ａブロア
１８原水貯留槽
１８ａ撹拌機
１９第二の廃水流路
２１第三の廃水流路 1 Wastewater treatment device 2 Wastewater treatment device 11 Treatment tank 12 First addition means 12a First tank 12b First supply flow path 12c First pump 13 Second addition means 13a Second tank 13b Second Supply flow path 13c Second pump 14 Treated water storage tank 15 First wastewater flow path 16 Treated water flow path 17 Disperser 17a Blower 18 Raw water storage tank 18a Stirrer 19 Second wastewater flow path 21 Third wastewater Channel

Claims

The waste water containing ammonia Tai窒element, a device for processing using aerobic direct nitrogen gas bacterium,
A treatment tank for treating the wastewater and
A first adding means for adding the aerobic direct nitrogen gas bacterium into the waste water,
A second addition means for adding a nitrification inhibitor to the wastewater,
Equipped with a,
The treatment tank is a treatment tank in which the inside of the tank is maintained under aerobic conditions.
The aerobic direct nitrogen gasifying bacterium is Alcaligenes faecalis.
The nitrification inhibitor, Ru least one der of allyl thiourea and 1-amidino-2-thiourea, wastewater treatment apparatus.

The wastewater treatment apparatus according to claim 1, further comprising a raw water storage tank for storing the wastewater upstream of the treatment tank.

The first addition means is a means for directly adding aerobic nitrogen gasifying bacteria to the wastewater in the treatment tank, and the second addition means is a means for adding a nitrification inhibitor to the wastewater in the treatment tank. , The wastewater treatment apparatus according to claim 1.

The first addition means is a means for directly adding aerobic nitrogen gasifying bacteria to the wastewater in the treatment tank, and the second addition means is a means for adding a nitrification inhibitor to the wastewater in the raw water storage tank. The wastewater treatment apparatus according to claim 2.

The wastewater treatment apparatus according to any one of claims 1 to 4, wherein the aerobic direct nitrogen gasifying bacterium is Alcaligenes faecalis No. 4 strain (FERM P-21814).

The waste water containing ammonia Tai窒element, a method for processing a processing tank with aerobic direct nitrogen gas bacterium,
A first adding step of adding the aerobic direct nitrogen gas bacterium into the waste water,
The second addition step of adding the nitrification inhibitor to the wastewater, and
Have a,
The treatment tank is a treatment tank in which the inside of the tank is maintained under aerobic conditions.
The aerobic direct nitrogen gasifying bacterium is Alcaligenes faecalis.
The nitrification inhibitor, Ru least one der of allyl thiourea and 1-amidino-2-thiourea, processing method of the waste water.

The wastewater treatment method according to claim 6 , wherein the wastewater before treatment is stored in a raw water storage tank.

The first addition step is a step of adding aerobic direct nitrogen gasifying bacteria to the wastewater in the treatment tank, and the second addition step is a step of adding a nitrification inhibitor to the wastewater in the treatment tank. , The method for treating wastewater according to claim 6 .

The first addition step is a step of adding aerobic direct nitrogen gasifying bacteria to the wastewater in the treatment tank, and the second addition step is a step of adding a nitrification inhibitor to the wastewater in the raw water storage tank. The wastewater treatment method according to claim 7 .

The method for treating wastewater according to any one of claims 6 to 9 , wherein 0.3 to 80 mg of a nitrification inhibitor is added to 1 L of wastewater.

The method for treating wastewater according to claim 10 , wherein 0.75 to 55 mg of a nitrification inhibitor is added to 1 L of wastewater.

The method for treating wastewater according to any one of claims 6 to 11 , wherein the aerobic direct nitrogen gasifying bacterium is Alcaligenes faecalis No. 4 strain (FERM P-21814).