JPH09248580A - Removing method of ammonia in sea water and device therefor - Google Patents
Removing method of ammonia in sea water and device thereforInfo
- Publication number
- JPH09248580A JPH09248580A JP8057435A JP5743596A JPH09248580A JP H09248580 A JPH09248580 A JP H09248580A JP 8057435 A JP8057435 A JP 8057435A JP 5743596 A JP5743596 A JP 5743596A JP H09248580 A JPH09248580 A JP H09248580A
- Authority
- JP
- Japan
- Prior art keywords
- ozone
- seawater
- ammonia
- oxidant
- treated
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、水族館や水産試験
場等の水槽における飼育海水の浄化に関し、より詳しく
は、水生生物に対し強い毒性を示すアンモニアをオゾン
処理によって除去する方法およびこれに用いる装置に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to purification of breeding seawater in aquariums such as aquariums and aquatic laboratories, and more particularly to a method for removing ammonia, which is highly toxic to aquatic organisms, by ozone treatment and an apparatus used therefor. Regarding
【０００２】[0002]
【従来の技術】従来、飼育海水中に溶存するアンモニア
を除去する場合、濾材を充填した濾過器に海水を通し、
この際、濾材表面や濾材中に生育しているアンモニア酸
化細菌および亜硝酸酸化細菌の働きにより、海水中のア
ンモニアを最終的に硝酸に変換するアンモニア硝化が行
われる。この反応は次の式で示される。2. Description of the Related Art Conventionally, when removing ammonia dissolved in breeding seawater, seawater is passed through a filter filled with a filter medium,
At this time, ammonia nitrification, which finally converts ammonia in seawater to nitric acid, is performed by the action of the ammonia-oxidizing bacteria and the nitrite-oxidizing bacteria growing on the surface of the filter medium and in the filter medium. This reaction is shown by the following formula.
【０００３】[0003]
【式１】 ＮＨ4 ＋ ＋ ３／２Ｏ2 → ＮＯ2 − ＋ ２Ｈ＋ ＋ Ｈ2 Ｏ ＮＯ2 − ＋ １／２Ｏ2 → ＮＯ3 − [Formula 1] NH 4 + + 3 / 2O 2 → NO 2 − + 2H + + H 2 O NO 2 − + 1 / 2O 2 → NO 3 −
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、上記の
ようなアンモニア硝化を行うと、硝酸イオン濃度の上昇
に伴ってｐＨが低下することとなる。そして、この場
合、生じた硝酸イオンは、魚類、その他の水生生物に対
して、アンモニアほど強い毒性は示さないが、高濃度に
なると有害である。また、ｐＨの低下も飼育環境上好ま
しくない。However, when the above-mentioned ammonia nitrification is carried out, the pH is lowered as the nitrate ion concentration is increased. Then, in this case, the produced nitrate ions do not show as strong toxicity to fish and other aquatic organisms as ammonia does, but are harmful at high concentrations. In addition, lowering the pH is not preferable in terms of breeding environment.
【０００５】したがって、飼育環境をさらに向上させる
には、飼育海水中の硝酸イオンを除去する、いわゆる脱
窒が必要であるが、そのためには脱窒工程を行う設備を
新たに設けなければならず、設備コストの増大および海
水処理スペースの拡大を招くこととなる。[0005] Therefore, in order to further improve the breeding environment, it is necessary to remove nitrate ions in the breeding seawater, that is, so-called denitrification, but for that purpose, equipment for carrying out the denitrification step must be newly provided. This will increase the equipment cost and the seawater treatment space.
【０００６】このため、現在、殆どの水族館では、上記
アンモニア酸化細菌等の微生物によるアンモニア硝化に
よって生ずる硝酸イオンの除去は行われておらず、ごく
一部のところで、硝酸イオンを除去するための試験が行
われているにすぎない。For this reason, at present, most aquariums do not remove nitrate ions produced by ammonia nitrification by microorganisms such as the above-mentioned ammonia-oxidizing bacteria, and a test for removing nitrate ions at a small part is performed. Is only taking place.
【０００７】本発明の目的は、上記の点に鑑み、硝酸イ
オンを生ずることなく、またｐＨを低下させずに飼育海
水中におけるアンモニアを除去することができるアンモ
ニア除去法およびこれに用いる装置を提供することにあ
る。In view of the above points, an object of the present invention is to provide an ammonia removing method and an apparatus used therefor capable of removing ammonia in rearing seawater without generating nitrate ions and without lowering the pH. To do.
【０００８】[0008]
【課題を解決するための手段】本発明方法は、濾過処理
の前段または後段において、処理すべき海水の少なくと
も一部に、所要濃度のオゾンを含有するガスを吹き込ん
でオゾンと海水中の臭素イオンとを反応させ、生成した
残留性オキシダントによってアンモニアを分解すると共
に、オゾンと残留性オキシダントの殺菌性により海水中
の微生物の増殖を抑制して、微生物によるアンモニア硝
化を阻止することを特徴とするオゾン処理による海水中
のアンモニア除去法である。According to the method of the present invention, in a stage before or after a filtration process, a gas containing ozone at a required concentration is blown into at least a part of seawater to be treated so that ozone and bromine ions in the seawater are blown. The ozone is characterized by decomposing ammonia by the residual oxidant produced by reacting with and suppressing the growth of microorganisms in seawater by the bactericidal property of ozone and the residual oxidant, and preventing ammonia nitrification by microorganisms. It is a method of removing ammonia in seawater by treatment.
【０００９】本発明によるアンモニア除去法において、
濾過処理後の海水をオゾン処理した後、その処理水の一
部を濾過器に戻すことが好ましい。これによって濾過器
内での微生物の増殖を抑制しつつ、海水中のアンモニア
除去率を向上させることができる。In the method for removing ammonia according to the present invention,
After the seawater after the filtration treatment is subjected to ozone treatment, it is preferable to return a part of the treated water to the filter. This makes it possible to improve the removal rate of ammonia in seawater while suppressing the growth of microorganisms in the filter.
【００１０】本発明によるアンモニア除去法において、
オゾン処理した海水中に含まれる残留性オキシダントを
触媒によって分解除去するのが好ましい。オキシダント
を分解する触媒としては活性炭等が挙げられる。In the method for removing ammonia according to the present invention,
It is preferable to decompose and remove the residual oxidant contained in the ozone-treated seawater with a catalyst. Examples of the catalyst that decomposes the oxidant include activated carbon.
【００１１】例えば、海水におけるアンモニア濃度が
０．１〜１ｍｇ−Ｎ／リットルで、かつＣＯＤが２ｍｇ
／リットル以下のとき、残留性オキシダント濃度が２〜
６ｍｇ−Ｏ3 ／リットルとなるようにオゾンガス吹き込
み量を設定する。For example, the ammonia concentration in seawater is 0.1 to 1 mg-N / liter and the COD is 2 mg.
/ Liter or less, the residual oxidant concentration is 2 to
The amount of ozone gas blown is set so as to be 6 mg-O 3 / liter.
【００１２】本発明方法によれば、海水中のアンモニア
は下記のような作用によって除去せられる。According to the method of the present invention, ammonia in seawater can be removed by the following actions.
【００１３】すなわち、海水中には臭素イオンが６０ｐ
ｐｍ程度含まれており、これがオゾンと反応して次亜臭
素酸イオンを主成分とする残留性オキシダントが生成
し、該オキシダントによってアンモニアが分解される。That is, bromine ions of 60 p are present in seawater.
It is contained in about pm, and this reacts with ozone to generate a residual oxidant containing hypobromite ion as a main component, and ammonia is decomposed by the oxidant.
【００１４】 Ｂｒ− ＋ Ｏ3 → ＢｒＯ− ＋ Ｏ2 ３ＨＢｒＯ ＋ ２ＮＨ3 → Ｎ2 ＋ ３Ｂｒ ＋ ３Ｈ2 Ｏ また、オゾンと残留性オキシダントの殺菌性により海水
中の微生物の増殖が抑制され、微生物によるアンモニア
硝化が阻止されることから、硝酸イオンは生じず、ｐＨ
の低下も起こらないこととなる。Br − + O 3 → BrO − + O 2 3HBrO + 2NH 3 → N 2 + 3Br + 3H 2 O In addition, the bactericidal properties of ozone and residual oxidant suppress the growth of microorganisms in seawater, and Since nitrification of ammonia is blocked, nitrate ions do not occur and the pH
Will not occur.
【００１５】上述した海水中のアンモニア除去法に使用
する本発明装置は、オゾン発生器と、オゾン発生器から
供給されるオゾンガスによって海水の曝気処理を行うオ
ゾン曝気塔と、海水を濾過する濾過器とを備えている。The apparatus of the present invention used in the method for removing ammonia in seawater described above comprises an ozone generator, an ozone aeration tower for aerating seawater with ozone gas supplied from the ozone generator, and a filter for filtering seawater. It has and.
【００１６】また、オゾン処理した海水中に含まれる残
留性オキシダントを分解除去するための触媒が充填され
たオキシダント除去塔を設けるのが好ましい。Further, it is preferable to provide an oxidant removing column packed with a catalyst for decomposing and removing residual oxidant contained in the ozone-treated seawater.
【００１７】[0017]
【発明の実施の形態】次に、本発明の実施例について説
明する。 実施例１ 図１に示すように、水槽(1) から出たアンモニア濃度
０．５ｍｇ−Ｎ／リットルの海水をオゾン曝気塔(2) に
流入させ、残留性オキシダントが３．５ｍｇ−Ｏ3 ／リ
ットルとなるように、海水にオゾン発生器(3) からオゾ
ン含有ガスを吹き込んだ。ついで、オゾン曝気塔(2) か
ら出た海水を砂濾過器(4) で濾過し、この濾過海水を活
性炭が充填されたオキシダント除去塔(5) に流入させて
海水中のオキシダントを分解除去した。Next, embodiments of the present invention will be described. Example 1 As shown in FIG. 1, seawater having an ammonia concentration of 0.5 mg-N / liter discharged from a water tank (1) was allowed to flow into an ozone aeration tower (2), and residual oxidant was 3.5 mg-O 3 /. The ozone-containing gas was blown into the seawater from the ozone generator (3) so that the volume became 1 liter. Next, the seawater discharged from the ozone aeration tower (2) was filtered with a sand filter (4), and this filtered seawater was introduced into an oxidant removal tower (5) filled with activated carbon to decompose and remove the oxidant in the seawater. .
【００１８】このようにして、海水を水槽(1) →オゾン
曝気塔(2) →砂濾過器(4) →オキシダント除去塔(5) →
水槽(1) のように１時間循環処理したところ、図２に示
すように、海水中のアンモニア濃度は最終的に０．００
４ｍｇ−Ｎ／リットル以下となった。また、海水のｐＨ
を測定したところ、上述したオゾン処理によるアンモニ
ア除去の前後でｐＨの変化はほとんどなく、約８．１で
あった。さらに、上記砂濾過器(4) 中で硝化細菌の繁殖
の有無を調べたが、該細菌の繁殖は認められなかった。In this way, the seawater tank (1) → ozone aeration tower (2) → sand filter (4) → oxidant removal tower (5) →
When it was circulated for 1 hour like the water tank (1), the ammonia concentration in the seawater finally reached 0.000 as shown in Fig.2.
It became 4 mg-N / liter or less. Also, the pH of seawater
Was measured, and it was about 8.1 with almost no change in pH before and after the removal of ammonia by the ozone treatment. Furthermore, the presence or absence of breeding of nitrifying bacteria was examined in the sand filter (4), but the breeding of the bacteria was not observed.
【００１９】また、上記海水処理において、水槽(1) か
ら出た海水の一部をオゾン曝気塔(2) に流入させずに、
砂濾過器(4) へ流入させたが、この場合も上記と同様の
処理結果が得られた。In the above seawater treatment, a part of seawater discharged from the water tank (1) is not allowed to flow into the ozone aeration tower (2),
Although it was made to flow into the sand filter (4), the same treatment result as above was obtained in this case as well.
【００２０】なお、海水中のオキシダントのモニタリン
グおよび分析法は以下の通りである。The method of monitoring and analyzing oxidants in seawater is as follows.
【００２１】(1) オキシダントのモニタリング オキシダントはプロセス用全塩素分析計（ＤＰＤ）でモ
ニタすることができる。この場合、測定値の単位はｍｇ
−Ｃｌ／リットルとなる。本明細書中のデータはすべて
手分析（ＫＩ法）による測定値で、単位はｍｇ−Ｏ3 ／
リットルであるが、これらは分子量比で換算できる。
（ｍｇ−Ｃｌ／リットル）＝（ｍｇ−Ｏ3／リットル）
×１．４７７。例えば、「残留性オキシダント濃度が２
〜６ｍｇ−Ｏ3 ／リットル」となるようなオゾンガスを
注入する場合、上記「２〜６ｍｇ−Ｏ3 ／リットル」は
塩素換算で３〜９ｍｇ−Ｃｌ／リットルとなる。(1) Monitoring of oxidant The oxidant can be monitored by a process total chlorine analyzer (DPD). In this case, the unit of measurement is mg
-Cl / liter. The value measured by a data herein all manual analysis (KI method), the unit is mg-O 3 /
Although it is liter, these can be converted by the molecular weight ratio.
(Mg-Cl / L) = (mg-O 3 / L)
× 1.477. For example, "the residual oxidant concentration is 2
If injecting ~6mg-O 3 / liter "become such ozone gas, the" 2-6 mg-O 3 / l "becomes 3~9mg-Cl / liter chlorine terms.
【００２２】プロセス用全塩素分析計としては、ポンプ
カラリーメータ（ハック社製）、残留塩素分析計ＣＬ−
１７型（ハック社製）などが例示される。As the total chlorine analyzer for the process, a pump colorimeter (manufactured by Hack) and a residual chlorine analyzer CL-
Type 17 (manufactured by Hack) is exemplified.
【００２３】(2) 残留性オキシダント分析法（ＫＩ法） サンプル液にＫＩ水溶液を加え、２５℃で１０分間反応
させた後、３５２ｎｍで吸光度を測定する。(2) Persistent oxidant analysis method (KI method) A KI aqueous solution is added to the sample solution, and the mixture is reacted at 25 ° C for 10 minutes, and then the absorbance is measured at 352 nm.
【００２４】具体的には、サンプル濃度によって次の２
つの方法で測定をする。Specifically, depending on the sample concentration, the following 2
Measure in one of two ways.
【００２５】０．５ｍｇ−Ｏ3 ／リットル以上の場合 サンプル液１０ｍｌに２％ＫＩ水溶液１０ｍｌを加え、
混合する。２５℃で１０分間反応を行った後、３５２ｎ
ｍの吸光度を測定する。標準液としてＩ3 液を使用す
る。In case of 0.5 mg-O 3 / liter or more, 10 ml of 2% KI aqueous solution is added to 10 ml of sample solution,
Mix. After reacting at 25 ° C for 10 minutes, 352n
Measure absorbance at m. Solution I 3 is used as a standard solution.
【００２６】０．５ｍｇ−Ｏ3 ／リットル以下の場合 サンプル液２０ｍｌに２０％ＫＩ水溶液１ｍｌを加え、
混合する。２５℃で１０分間反応を行った後、３５２ｎ
ｍの吸光度を測定する。標準液としてＩ3 液を使用す
る。In the case of 0.5 mg-O 3 / liter or less, 1 ml of 20% KI aqueous solution was added to 20 ml of the sample solution,
Mix. After reacting at 25 ° C for 10 minutes, 352n
Measure absorbance at m. Solution I 3 is used as a standard solution.
【００２７】実施例２ 図３に示すように、水槽(1) から出たアンモニア濃度
０．５ｍｇ−Ｎ／リットルの海水を砂濾過器(4) で濾過
し、この濾過海水をオゾン曝気塔(2) に導いて、同海水
に、オゾン発生器(3) で得られたオゾン含有ガスを吹き
込んだ。この海水をオキシダント除去塔(5) に流入させ
てオキシダントを分解除去した。Example 2 As shown in FIG. 3, seawater having an ammonia concentration of 0.5 mg-N / liter discharged from the water tank (1) was filtered by a sand filter (4), and the filtered seawater was supplied to an ozone aeration tower ( After leading to 2), the ozone-containing gas obtained by the ozone generator (3) was blown into the seawater. The seawater was introduced into the oxidant removal tower (5) to decompose and remove the oxidant.
【００２８】このようにして、海水を水槽(1) →砂濾過
器(4) →オゾン曝気塔(2) →オキシダント除去塔(5) →
水槽(1) のように１時間循環処理したところ、実施例１
と同様の処理結果が得られた。また、オゾン曝気塔(2)
から出た海水の一部を砂濾過器(4) へ戻して循環させた
が、この場合も同様の処理結果が得られた。In this way, the seawater tank (1) → sand filter (4) → ozone aeration tower (2) → oxidant removal tower (5) →
After circulating treatment for 1 hour like the water tank (1), Example 1
Similar processing results were obtained. Also, ozone aeration tower (2)
A part of seawater discharged from the tank was returned to the sand filter (4) and circulated, and in this case, the same treatment result was obtained.
【００２９】このようにオゾン曝気塔を出た海水の一部
を砂濾過器に必ず戻す。そうしなければ砂濾過器中で微
生物が増殖する。In this way, a part of the seawater that has exited the ozone aeration tower must be returned to the sand filter. Otherwise, microorganisms will grow in the sand filter.
【００３０】[0030]
【発明の効果】本発明方法によれば、海水中の臭素イオ
ンがオゾンと反応して次亜臭素酸イオンを主とする残留
性オキシダントが生成され、該オキシダントによってア
ンモニアが分解される。According to the method of the present invention, bromine ions in seawater react with ozone to produce a residual oxidant mainly composed of hypobromite ion, and ammonia is decomposed by the oxidant.
【００３１】また、オゾンと残留性オキシダントの殺菌
性により海水中の微生物の増殖が抑制され、微生物によ
るアンモニア硝化が阻止されることから、硝酸イオンは
生じず、ｐＨの低下も起こらない。Since the bactericidal properties of ozone and residual oxidant suppress the growth of microorganisms in seawater and prevent ammonia nitrification by microorganisms, nitrate ions are not generated and the pH is not lowered.
【００３２】したがって、本発明方法によれば、硝酸イ
オン自体が生じないため、従来のような脱窒工程の設備
を設ける必要もなく、設備コストや海水処理スペースの
増大を招くこともない。Therefore, according to the method of the present invention, since nitrate ions themselves are not generated, there is no need to install equipment for the conventional denitrification process, and there is no increase in equipment cost and seawater treatment space.
【００３３】このように、本発明方法によれば、飼育海
水のアンモニアをコスト的に有利に除去することができ
る。As described above, according to the method of the present invention, ammonia in the breeding seawater can be removed cost effectively.
【図面の簡単な説明】[Brief description of drawings]
【図１】本発明の一実施例を示すフロースキームであ
る。FIG. 1 is a flow scheme showing an embodiment of the present invention.
【図２】アンモニア濃度の経時変化を示すグラフであ
る。FIG. 2 is a graph showing changes in ammonia concentration over time.
【図３】本発明の他の実施例を示すフロースキームであ
る。FIG. 3 is a flow scheme showing another embodiment of the present invention.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｃ０２Ｆ 1/76 Ｃ０２Ｆ 1/76 Ｃ Ｂ０１Ｄ 35/02 Ｃ ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification number Internal reference number FI Technical indication C02F 1/76 C02F 1/76 C B01D 35/02 C
Claims (6)
理すべき海水の少なくとも一部に、所要濃度のオゾンを
含有するガスを吹き込んでオゾンと海水中の臭素イオン
とを反応させ、生成した残留性オキシダントによってア
ンモニアを分解すると共に、オゾンと残留性オキシダン
トの殺菌性により海水中の微生物の増殖を抑制して、微
生物によるアンモニア硝化を阻止することを特徴とする
オゾン処理による海水中のアンモニア除去法。1. A residual property produced by blowing a gas containing a required concentration of ozone into at least a part of seawater to be treated to cause the ozone to react with bromine ions in the seawater before or after the filtration treatment. A method for removing ammonia in seawater by ozone treatment, characterized in that ammonia is decomposed by an oxidant, and the bactericidal properties of ozone and residual oxidant suppress the growth of microorganisms in seawater to prevent ammonia nitrification by microorganisms.
その処理水の一部を濾過器に戻す請求項１記載のアンモ
ニア除去法。2. Seawater after filtration is treated with ozone,
The ammonia removing method according to claim 1, wherein a part of the treated water is returned to the filter.
オキシダントを触媒によって分解除去する請求項１また
は２記載のアンモニア除去法。3. The ammonia removing method according to claim 1, wherein the residual oxidant contained in the ozone-treated seawater is decomposed and removed by a catalyst.
１ｍｇ−Ｎ／リットルで、かつＣＯＤが２ｍｇ／リット
ル以下のとき、残留性オキシダント濃度が２〜６ｍｇ−
Ｏ3 ／リットルとなるようにオゾンガス吹き込み量を設
定する請求項１〜３のうちのいずれかに記載のアンモニ
ア除去法。4. The concentration of ammonia in seawater is 0.1 to 10.
When the COD is 1 mg-N / liter and the COD is 2 mg / liter or less, the residual oxidant concentration is 2 to 6 mg-.
The ammonia removal method according to any one of claims 1 to 3, wherein the amount of ozone gas blown in is set to O 3 / liter.
されるオゾン含有ガスによって海水の曝気処理を行うオ
ゾン曝気塔と、海水を濾過する濾過器とを備えた海水中
のアンモニア除去装置。5. An apparatus for removing ammonia in seawater, comprising an ozone generator, an ozone aeration tower that performs aeration treatment of seawater with an ozone-containing gas supplied from the ozone generator, and a filter that filters seawater.
オキシダントを分解除去するための触媒が充填されたオ
キシダント除去塔を有する請求項５記載の装置。6. The apparatus according to claim 5, further comprising an oxidant removal column packed with a catalyst for decomposing and removing residual oxidant contained in the ozone-treated seawater.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05743596A JP3393282B2 (en) | 1996-03-14 | 1996-03-14 | Ammonia removal method from seawater |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05743596A JP3393282B2 (en) | 1996-03-14 | 1996-03-14 | Ammonia removal method from seawater |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09248580A true JPH09248580A (en) | 1997-09-22 |
| JP3393282B2 JP3393282B2 (en) | 2003-04-07 |
Family
ID=13055583
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP05743596A Expired - Fee Related JP3393282B2 (en) | 1996-03-14 | 1996-03-14 | Ammonia removal method from seawater |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3393282B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100296887B1 (en) * | 1998-10-09 | 2001-10-26 | 조현서 | Water purification system for marine fish farm constructed on land |
| JP2021000606A (en) * | 2019-06-21 | 2021-01-07 | オルガノ株式会社 | Water treatment method and water treatment apparatus |
-
1996
- 1996-03-14 JP JP05743596A patent/JP3393282B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100296887B1 (en) * | 1998-10-09 | 2001-10-26 | 조현서 | Water purification system for marine fish farm constructed on land |
| JP2021000606A (en) * | 2019-06-21 | 2021-01-07 | オルガノ株式会社 | Water treatment method and water treatment apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3393282B2 (en) | 2003-04-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20130048558A1 (en) | Water treatment method and ultrapure water producing method | |
| JP2015181973A (en) | Membrane filtration system, membrane filtration method, and apparatus of producing rearing water for aquatic organism | |
| JP2019068772A (en) | Water treatment device and water treatment method | |
| JP4092454B2 (en) | Water treatment method | |
| JP5259311B2 (en) | Water treatment method and water treatment system used therefor | |
| JPH07124593A (en) | Highly advanced water purifying treatment method | |
| JP3393282B2 (en) | Ammonia removal method from seawater | |
| JP7212478B2 (en) | MEMBRANE FILTRATION SYSTEM AND MEMBRANE FILTRATION METHOD | |
| JP5126926B2 (en) | Ultra-high water treatment method and water treatment system used therefor | |
| JP4334404B2 (en) | Water treatment method and water treatment system | |
| US20230322595A1 (en) | Wastewater Ozone Treatment | |
| JP5612364B2 (en) | Environmental water purification method | |
| JP3203291B2 (en) | Removal method of ammonia nitrogen from raw water for tap water | |
| JP3377346B2 (en) | Organic wastewater treatment method and apparatus | |
| Kutty et al. | Studies on THMs formation by various disinfectants in seawater desalination plants | |
| Ozawa et al. | Ozonation of seawater-Applicability of ozone for recycled hatchery cultivation | |
| JPH06154774A (en) | Cleaning method for water for raising fresh water fish | |
| JP2542292B2 (en) | Purification method for fish tank water | |
| JP2005046697A (en) | Activated sludge treatment method | |
| JP2004160349A (en) | Water cleaning apparatus for fish and shellfish | |
| JPH1043771A (en) | Denitrifying treatment and device therefor | |
| JPH03181391A (en) | Water treating device for decomposition ammoniacal nitrogen | |
| JP2007069190A (en) | Method and apparatus for treating nitrite nitrogen-containing water | |
| JPH06154787A (en) | Device for removing nitrogen | |
| JPH09141275A (en) | Treatment of organic waste water |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20021126 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090131 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090131 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100131 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110131 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110131 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120131 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130131 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140131 Year of fee payment: 11 |
|
| LAPS | Cancellation because of no payment of annual fees |