JPH0782005B2 - Free chlorine measuring device - Google Patents
Free chlorine measuring deviceInfo
- Publication number
- JPH0782005B2 JPH0782005B2 JP17594589A JP17594589A JPH0782005B2 JP H0782005 B2 JPH0782005 B2 JP H0782005B2 JP 17594589 A JP17594589 A JP 17594589A JP 17594589 A JP17594589 A JP 17594589A JP H0782005 B2 JPH0782005 B2 JP H0782005B2
- Authority
- JP
- Japan
- Prior art keywords
- hypochlorous acid
- sample water
- free chlorine
- water
- concentration
- 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.)
- Expired - Lifetime
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Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は上下水道水，工業用水，河川水等に存在する
遊離塩素の測定装置に係り、特に試料水中の全遊離塩素
濃度を正確に測定する遊離塩素測定装置に関する。TECHNICAL FIELD The present invention relates to an apparatus for measuring free chlorine existing in water and sewage water, industrial water, river water, etc., and particularly accurately measuring the total free chlorine concentration in sample water. The present invention relates to a free chlorine measuring device.
水の消毒には一般に塩素（Cl2）が用いられる。塩素を
水中に注入した場合、次亜塩素酸（HOCl）および次亜塩
素酸イオン（OCl-）を生じる。Chlorine (Cl 2 ) is generally used to disinfect water. When injected chlorine into water, hypochlorite (HOCl) and hypochlorite ions - resulting in (OCl).
Cl2＋H2OHOCl＋H+＋Cl- （１） HOClOCl-＋H+ （２） ここで塩素，次亜塩素酸及び次亜塩素酸イオンを総称し
て遊離塩素といい、これらは強い殺菌力を持つ。Cl 2 + H 2 OHOCl + H + + Cl − (1) HOClOCl − + H + (2) Here, chlorine, hypochlorous acid and hypochlorite ion are collectively called free chlorine, which has a strong bactericidal activity.
さて、この殺菌処理における塩素の注入量は、例えば水
道法では「給水せんにおける水が、遊離残留塩素を0.1p
pm以上保持するように塩素消毒をすること」と義務付け
られているので、遊離塩素の監視は不可欠である。Now, the chlorine injection amount in this sterilization treatment is, for example, in the Water Supply Act, "
It is mandatory to sterilize the chlorine so that it is maintained at pm or more. Therefore, monitoring of free chlorine is indispensable.
遊離塩素の存在割合、つまり塩素，次亜塩素酸，次亜塩
素酸イオンの存在割合は試料水のpHの影響を大きく受け
る。pHを通常のpH範囲、例えば飲料水基準のpH＝5.8〜
8.6に限定してみても次亜塩素酸と次亜塩素酸イオンが
混在している領域であり、その割合は大きく異なる。し
たがって塩素殺菌を行う場合には次亜塩素酸，次亜塩素
酸イオンの各濃度、あるいはその合計濃度を知ることが
重要である。The abundance of free chlorine, that is, the abundance of chlorine, hypochlorous acid, and hypochlorite ions, is greatly influenced by the pH of the sample water. The pH is in the normal pH range, for example, the pH based on drinking water = 5.8-
Even if it is limited to 8.6, it is a region in which hypochlorous acid and hypochlorite ions coexist, and the ratio is greatly different. Therefore, when performing chlorine sterilization, it is important to know the respective concentrations of hypochlorous acid and hypochlorite ion, or their total concentrations.
このための手段が実公昭59−42693号公報および特開昭6
3−27745号公報に開示されている。Means for this are disclosed in Japanese Utility Model Publication No. 59-42693 and Japanese Patent Laid-Open Publication No.
It is disclosed in Japanese Patent Publication No. 327745.
実公昭59−42693号公報に開示された考案は式（２）の
解離平衡がpHに依存するとともに、その解離定数は水温
が既知になれば定まることに着目し、隔膜式次亜塩素酸
電極で試料水中の次亜塩素酸濃度を測定すると同時に試
料水のpH及び水温を検出し、下記の式（３） 〔OCl-〕＝Ｋ（Ｔ）＊〔HOCl〕＊10pH （３） により演算で次亜塩素酸イオン濃度を求め、これにより
次亜塩素酸と次亜塩素酸イオンとの合計濃度を求める。The device disclosed in Japanese Utility Model Publication No. 59-42693 discloses that the dissociation equilibrium of formula (2) depends on pH and that the dissociation constant is determined when the water temperature becomes known. in the hypochlorous acid concentration of sample water to detect the pH and temperature of which at the same time the sample water measurement, the following equation (3) [OCl -] = calculated by K (T) * [HOCl] * 10 pH (3) Then, the hypochlorite ion concentration is obtained, and thereby the total concentration of hypochlorous acid and hypochlorite ion is obtained.
特開昭63−27745号公報に開示された発明は、試料水のp
Hが３〜５であれば遊離塩素はほぼ100％次亜塩素酸の形
態で存在することに着目したもので、試料水を実質的に
希釈することなくpHを３〜５に調整し、この試料水中の
次亜塩素酸を隔膜式次亜塩素酸電極で測定し、全遊離塩
素濃度を求めるものである。The invention disclosed in Japanese Patent Application Laid-Open No. 63-27745 is based on p
When H was 3-5, we paid attention to the fact that free chlorine exists in the form of almost 100% hypochlorous acid, and the pH was adjusted to 3-5 without substantially diluting the sample water. Hypochlorous acid in sample water is measured with a diaphragm type hypochlorous acid electrode to obtain the total free chlorine concentration.
実公昭59−42693号公報に開示された考案及び特開昭63
−27745号公報に開示された発明のいずれも、試料水中
の次亜塩素酸の測定に隔膜式次亜塩素酸電極を用いてい
る。この隔膜式次亜塩素酸電極は電解液が封入され、一
部に次亜塩素酸を透過する隔膜（例えば、多孔質テフロ
ン膜（テフロンはデュポンの商品名））を持ち、内部に
アノード及びカソードが収容された構造のものである。The device disclosed in Japanese Utility Model Publication No. 59-42693 and Japanese Patent Laid-Open No. 63-63
In any of the inventions disclosed in Japanese Patent Publication No. 27745, a diaphragm-type hypochlorous acid electrode is used for measuring hypochlorous acid in sample water. This diaphragm type hypochlorous acid electrode has an electrolytic solution enclosed therein and has a diaphragm (for example, a porous Teflon membrane (Teflon is a DuPont brand name)) that partially permeates hypochlorous acid, and has an anode and a cathode inside. It is of a structure that accommodates.
この隔膜は試料水に浸漬されている内に、試料水中の微
粒子の隔膜内の細孔への侵入や表面への汚れの付着によ
り次第に汚染される。このため試料水中の次亜塩素酸の
隔膜の透過特性が変化し、測定誤差が生じるという問題
がある。さらに隔膜式次亜塩素酸電極は定期的に内部電
解液の交換を行わなければならないという問題もある。While being immersed in the sample water, this diaphragm is gradually contaminated by the intrusion of fine particles in the sample water into the pores in the diaphragm and the adhesion of dirt to the surface. For this reason, there is a problem that the permeation characteristics of the hypochlorous acid diaphragm in the sample water change, resulting in a measurement error. Further, the diaphragm type hypochlorous acid electrode has a problem that the internal electrolytic solution must be periodically replaced.
この発明は上述の点に鑑みなされ、その目的は汚染され
ることがない次亜塩素酸の検知手段を用いることによ
り、信頼性に優れる全遊離塩素測定装置を提供すること
にある。The present invention has been made in view of the above points, and an object thereof is to provide an apparatus for measuring total free chlorine, which is excellent in reliability, by using a hypochlorous acid detection unit that is not contaminated.
上述の目的はこの発明によれば、 １）試料水中の次亜塩素酸を気相に移行させて行う遊離
塩素測定装置において、 （１）試料水中の次亜塩素酸をキャリアガス中に移行さ
せる気相抽出手段1,2,3,4と、 （２）キャリアガス中に移行した次亜塩素酸を検知して
試料水中の次亜塩素酸濃度〔HOCl〕を測定するIn2O3を
主成分とする金属酸化物半導体式ガス検知手段15と、 （３）試料水のpHを検知する手段５と、 （４）試料水の温度（Ｔ）を測定する手段６と、 （５）次亜塩素酸イオン濃度を〔OCl-〕,K2（Ｔ）を温
度によって決まる酸解離定数とするときに次式 〔OCl-〕＝K2（Ｔ）＊〔HOCl〕＊10pH および〔OCl-〕＋〔HOCl〕の計算を行う演算部９、とを
備えること、または ２）試料水中の次亜塩素酸を気相に移行させて行う遊離
塩素測定装置において、 （１）試料水中の次亜塩素酸をキャリアガス中に移行さ
せる気相抽出手段1,2,3,4と、 （２）キャリアガス中に移行した次亜塩素酸を検知して
試料水中の次亜塩素酸濃度を測定するIn2O3を主成分と
する金属酸化物半導体式ガス検知手段15と、 （３）試料水の塩素イオン濃度を〔Cl-〕とするときに
試料水のpHを下記範囲内にする pH調節手段31,33とを備えることにより達成される。The above-mentioned objects are according to the present invention: 1) In a free chlorine measuring apparatus for transferring hypochlorous acid in sample water to a gas phase, (1) transferring hypochlorous acid in sample water into a carrier gas Gas phase extraction means 1, 2, 3, 4 and (2) Mainly In 2 O 3 which measures the hypochlorous acid concentration [HOCl] in the sample water by detecting the hypochlorous acid transferred to the carrier gas. Metal oxide semiconductor gas detecting means 15 as a component, (3) means 5 for detecting the pH of sample water, (4) means 6 for measuring the temperature (T) of the sample water, (5) hypothesis the chlorate ion concentration [OCl -], the following equation when the acid dissociation constant determined K 2 (T) is the temperature [OCl -] = K 2 (T) * [HOCl] * 10 pH and [OCl -] Or [2] a free chlorine measuring apparatus for moving hypochlorous acid in the sample water to the gas phase, or , (1) Gas phase extraction means 1, 2, 3, 4 for migrating hypochlorous acid in the sample water into the carrier gas, and (2) Detecting the hypochlorous acid migrated in the carrier gas, the sample water A metal oxide semiconductor type gas detection means 15 containing In 2 O 3 as a main component for measuring the hypochlorous acid concentration of (3), and (3) when the chlorine ion concentration of the sample water is [Cl − ], Adjust the pH within the following range This is achieved by including the pH adjusting means 31 and 33.
試料水中の次亜塩素酸はキャリアガスとの接触によりキ
ャリアガス中に移行する。試料水からキャリアガス中に
移行した次亜塩素酸は、そのままの形であるいは分解し
た状態でIn2O3を主成分とする金属酸化物半導体式ガス
センサの抵抗を変化させるものと推定される。Hypochlorous acid in the sample water is transferred to the carrier gas by contact with the carrier gas. It is presumed that the hypochlorous acid transferred from the sample water into the carrier gas changes the resistance of the metal oxide semiconductor gas sensor containing In 2 O 3 as a main component in the form as it is or in the state of being decomposed.
請求項１に係る発明においてはIn2O3を主成分とする金
属酸化物半導体式ガスセンサで次亜塩素酸濃度が測定さ
れ、この次亜塩素酸濃度と試料水のpHと試料水の温度Ｔ
とから計算によって次亜塩素酸イオン濃度が求められる
ので〔HOCl〕＋〔OCl-〕により遊離塩素の総量が求ま
る。In the invention according to claim 1, the hypochlorous acid concentration is measured by a metal oxide semiconductor gas sensor containing In 2 O 3 as a main component, and the hypochlorous acid concentration, the pH of the sample water and the temperature T of the sample water are measured.
Since the hypochlorite ion concentration can be calculated from the above, the total amount of free chlorine can be calculated by [HOCl] + [OCl − ].
請求項２に係る発明においては試料水を所定のpHにする
と遊離塩素のうち次亜塩素酸の占める割合が95％以上に
なる。In the invention according to claim 2, when the sample water is brought to a predetermined pH, the proportion of hypochlorous acid in free chlorine becomes 95% or more.
以下にこの発明の実施例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.
第１図は請求項１の発明の実施例に係る装置の構成を示
す配置図である。第１図において、１は清浄な除湿空気
を得るための活性炭とシリカゲルが充填されたフィル
タ、２及び３はそれぞれ乾燥ガス，キャリアガス用の流
量計、４は抽出槽で内部に試料水があり、pH計５及び水
温計６が試料水中に浸漬されている。７は気相部の次亜
塩素酸を検出するためのIn2O3を主成分とする金属酸化
物半導体式ガスセンサを内蔵した測定チャンバ、８は乾
燥ガス及びキャリアガスを吸引するためのエアポンプ、
９は演算装置、10はサンプリングポンプである。測定チ
ャンバ７に内蔵されたIn2O3を主成分とする金属酸化物
半導体式ガスセンサ15の詳細が第２図に示される。In2O
3を主成分とする金属酸化物半導体式ガスセンサは電気
絶縁性基板、例えばアルミナ基板11、アルミナ基板11の
表面に蒸着により形成されたIn2O3を主成分とする金属
酸化物In2O3を主成分とする金属酸化物半導体薄膜12の
抵抗変化を測定するPt膜電極13A,13B、アルミナ基板11
の裏面に形成された気相中の水分、油脂分による感度の
経時的劣化を避けるためのPt膜ヒータ14により構成され
る。FIG. 1 is a layout diagram showing a configuration of an apparatus according to an embodiment of the present invention. In Fig. 1, 1 is a filter filled with activated carbon and silica gel for obtaining clean dehumidified air, 2 and 3 are dry gas, a flowmeter for carrier gas, 4 is an extraction tank with sample water inside , PH meter 5 and water temperature meter 6 are immersed in the sample water. 7 is a measurement chamber containing a metal oxide semiconductor gas sensor containing In 2 O 3 as a main component for detecting hypochlorous acid in the gas phase, 8 is an air pump for sucking dry gas and carrier gas,
Reference numeral 9 is an arithmetic unit, and 10 is a sampling pump. The details of the metal oxide semiconductor type gas sensor 15 containing In 2 O 3 as a main component built in the measurement chamber 7 are shown in FIG. In 2 O
Metal oxide semiconductor gas sensor is electrically insulating substrate 3 as a main component, such as alumina substrate 11, a metal oxide In 2 O 3 whose main component is In 2 O 3 formed by vapor deposition on the surface of the alumina substrate 11 Pt film electrodes 13A and 13B for measuring the resistance change of the metal oxide semiconductor thin film 12 containing as a main component, the alumina substrate 11
The Pt film heater 14 is formed on the back surface of the Pt film heater 14 for avoiding deterioration of sensitivity with time due to moisture and oil in the gas phase.
次に第１図，第２図に示した装置において、どのように
して遊離塩素の測定が行われるかについて述べる。Next, how the free chlorine is measured in the apparatus shown in FIGS. 1 and 2 will be described.
エアポンプ８によって周囲空気が装置内に吸引される。
この空気はフィルタ１で除湿，清浄化され、一方は流量
計２を通って乾燥ガスに、もう一方は流量計３を通って
キャリアガスになる。キャリアガスは抽出槽４内の気相
部に流入し、試料水中の次亜塩素酸は水面からキャリア
ガス中に拡散してくる。このキャリアガス中には次亜塩
素酸だけでなく、水蒸気も拡散してくる。抽出槽４から
測定チャンバ７に至る配管の温度が低ければこの水蒸気
は凝縮し、液滴になる。このようにして液滴ができれ
ば、キャリアガス中に抽出された次亜塩素酸が液滴部分
で再び気液平衡を起こし気相部の次亜塩素酸濃度が変化
するから、測定誤差の原因になる。この装置では水蒸気
が凝縮しないように、抽出槽４から測定チャンバ７に至
る配管の途中で、流量計２を経由してきた乾燥ガスと混
合している。この混合する箇所は抽出槽４になるべく近
いところが望ましい。Ambient air is sucked into the device by the air pump 8.
This air is dehumidified and purified by the filter 1, one of which becomes a dry gas through the flow meter 2 and the other of which becomes a carrier gas through the flow meter 3. The carrier gas flows into the gas phase in the extraction tank 4, and hypochlorous acid in the sample water diffuses into the carrier gas from the water surface. Not only hypochlorous acid but also water vapor diffuses into this carrier gas. If the temperature of the pipe from the extraction tank 4 to the measurement chamber 7 is low, this water vapor will condense into droplets. If droplets are formed in this way, hypochlorous acid extracted in the carrier gas causes vapor-liquid equilibrium again in the droplet portion, and the hypochlorous acid concentration in the gas phase portion changes, causing measurement error. Become. In this device, in order to prevent water vapor from condensing, it is mixed with the dry gas that has passed through the flow meter 2 in the middle of the pipe from the extraction tank 4 to the measurement chamber 7. It is desirable that this mixing position be as close as possible to the extraction tank 4.
乾燥ガスと混合された次亜塩素酸を含有するキャリアガ
スは、ついで測定チャンバ７に導かれてIn2O3を主成分
とする金属酸化物半導体式ガスセンサ15で次亜塩素酸濃
度が測定され、その濃度は演算装置９に入力される。演
算装置９にはさらに、抽出槽４内の試料水のpHおよび水
温がそれぞれpH計５、水温計６から入力される。The carrier gas containing hypochlorous acid mixed with the dry gas is then introduced into the measurement chamber 7 and the concentration of hypochlorous acid is measured by the metal oxide semiconductor gas sensor 15 containing In 2 O 3 as a main component. , Its concentration is input to the arithmetic unit 9. Further, the pH and the water temperature of the sample water in the extraction tank 4 are input to the arithmetic unit 9 from the pH meter 5 and the water temperature meter 6, respectively.
演算装置９では次亜塩素算濃度,pH,水温から次亜塩素酸
イオン濃度さらには全遊離塩素濃度の演算を行う。以下
に演算内容を説明する。The computing unit 9 computes the hypochlorite ion concentration and the total free chlorine concentration from the calculated hypochlorite concentration, pH and water temperature. The details of the calculation will be described below.
式（２）の解離平衡は平衡定数をK2（Ｔ）とすると次の
式で示される。The dissociation equilibrium of the equation (2) is represented by the following equation when the equilibrium constant is K 2 (T).
解離定数K2（Ｔ）は水温Ｔの関数であり、−log K
2（Ｔ）≒5097/T−92.77＋33.63＊log Tである。また
〔H+〕とpHの間には、pH＝−log〔H+〕の関係がある。
よって式（４）より〔OCl-〕は以下のように表現でき
る。 The dissociation constant K 2 (T) is a function of the water temperature T, and −log K
2 (T) ≈ 5097 / T-92.77 + 33.63 * log T. Further, there is a relation of pH = −log [H + ] between [H + ] and pH.
Therefore, from equation (4), [OCl − ] can be expressed as follows.
〔OCl-〕＝K2（Ｔ）＊〔HOCl〕＊10pH （５） したがって次亜塩素酸濃度,pH,水温が測定されれば、演
算により次亜塩素酸イオン濃度が求まり、さらには次亜
塩素酸と次亜塩素酸イオンの合計濃度、つまり全遊離塩
素濃度が求まる。[OCl − ] = K 2 (T) * [HOCl] * 10 pH (5) Therefore, if the hypochlorous acid concentration, pH, and water temperature are measured, the hypochlorite ion concentration can be calculated, and The total concentration of chlorous acid and hypochlorite ion, that is, the total free chlorine concentration can be obtained.
以上、この実施例では試料水中の次亜塩素酸の抽出方法
としてヘッドスペース法を用いた測定方法について説明
してきたが、この発明の抽出方法はヘッドスペース法に
限定さるものではなく、試料水中の次亜塩素酸を気相中
に拡散させ抽出する方法であればその方法を問わない。As described above, in this example, the measurement method using the headspace method as the extraction method of hypochlorous acid in the sample water has been described, but the extraction method of the present invention is not limited to the headspace method, and Any method may be used as long as it is a method of diffusing hypochlorous acid in the gas phase and extracting it.
第３図には抽出方法としてバブリング法を用いたときの
装置構成を示した。エアポンプ８でガスを吸引すると抽
出槽４内は減圧になるから、ボールディフューザー21か
らキャリアガスが試料水中に吹き込まれ、試料水中の次
亜塩素酸は気相部に抽出される。したがって第１図に示
した装置と同様に試料水中の次亜塩素酸濃度が測定され
る。このバブリング法は試料水中に強制的にキャリアガ
スを吹き込んでいることから、応答速度が速く、低濃度
まで測定可能であるという利点がある。FIG. 3 shows the apparatus configuration when the bubbling method is used as the extraction method. When the gas is sucked by the air pump 8, the inside of the extraction tank 4 is depressurized, so that the carrier gas is blown into the sample water from the ball diffuser 21 and the hypochlorous acid in the sample water is extracted to the gas phase part. Therefore, the concentration of hypochlorous acid in the sample water is measured in the same manner as the device shown in FIG. This bubbling method has an advantage that the carrier gas is forcibly blown into the sample water, so that the response speed is fast and it is possible to measure even a low concentration.
第４図は請求項２の発明の実施例に係る装置の構成を示
す配置図である。この発明は試料水に緩衝液を注入して
次亜塩素酸の存在割合をほぼ100％にしてから次亜塩素
酸を測定するもので、緩衝液33を試料水に注入するため
の薬液ポンプ31を備え、さらに演算の必要がないため測
定チャンバ７内のIn2O3を主成分とする金属酸化物半導
体式ガスセンサの出力は直接レコーダ32に接続されてい
る。FIG. 4 is a layout diagram showing a configuration of an apparatus according to an embodiment of the invention of claim 2. This invention is to measure hypochlorous acid after injecting a buffer solution into the sample water to make the existing ratio of hypochlorous acid almost 100%, and to pump the buffer solution 33 into the sample water. The output of the metal oxide semiconductor type gas sensor containing In 2 O 3 as a main component in the measurement chamber 7 is directly connected to the recorder 32 because there is no further calculation.
この装置において、抽出槽４内の試料水には薬液ポンプ
31によって緩衝液が添加され、pHの上限が6.15、下限が
水素イオン濃度と塩素イオン濃度の積〔H+〕＊〔Cl-〕
が3.84＊10-6になるように調節される。この条件を満た
せば試料水中の遊離塩素の95％以上が次亜塩素酸として
存在する。In this device, a chemical liquid pump is used for the sample water in the extraction tank 4.
31 buffer is added by, the upper limit of the pH is 6.15, the lower limit of hydrogen ion concentration and the chloride ion concentration product [H +] * [Cl -]
Is adjusted to 3.84 * 10 -6 . If this condition is satisfied, 95% or more of free chlorine in the sample water exists as hypochlorous acid.
理由を以下に説明する。式（１），式（２）の解離平衡
は第５図のようになり、次亜塩素酸としてほぼ100％存
在するためにはpHは所定の範囲に限定される。いま上
限，下限を次亜塩素酸として95％以上存在する範囲と定
義する。次亜塩素酸として95％以上存在するためには、
上限は次式を満たせばよい。The reason will be described below. The dissociation equilibrium of the formulas (1) and (2) is as shown in FIG. 5, and the pH is limited to a predetermined range in order that almost 100% of hypochlorous acid exists. Now, the upper and lower limits are defined as the range where 95% or more of hypochlorous acid exists. In order for 95% or more of hypochlorous acid to exist,
The upper limit should satisfy the following formula.
〔OCl-〕は、 であるから、式（７）を式（６）に代入して整理する
と、 〔H+〕≧19＊K2（Ｔ） （８） となる。通常、上下水道水，工業用水，河川水等の水温
は０〜25℃であるから、式（８）に結果的に値が大きく
なるK2（25）＝3.7＊10-8を代入すると、〔H+〕≧7.0＊
10-7、pHで表わすと6.15以下にすればよい。 [OCl -] is, Therefore, by substituting equation (7) into equation (6) and rearranging, [H + ] ≧ 19 * K 2 (T) (8). Normally, the water temperature of water for sewage, industrial water, river water, etc. is 0 to 25 ° C, so if we substitute K 2 (25) = 3.7 * 10 -8 , which results in a large value in equation (8), [H + ] ≧ 7.0 *
When expressed in 10 -7 and pH, it should be 6.15 or less.
一方、下限は次の条件を満たす必要がある。On the other hand, the lower limit must satisfy the following condition.
〔Cl2〕は、 K1（Ｔ）：式（１）の平衡定数 であるから、式（10）を式（９）に代入して整理する
と、 〔H+〕＊〔Cl-〕≦2.63＊10-2＊K1（Ｔ） （11） となる。上限を求めた時と同様に、上下水道水，工業用
水，河川水等の水温は０〜25℃であるから結果的に値が
小さくなるK1（０）＝1.46＊10-4を代入して、〔H+〕＊
〔Cl-〕≦3.84＊10-6となる。 [Cl 2 ] is K 1 (T): Since it is the equilibrium constant of equation (1), when equation (10) is substituted into equation (9) and rearranged, [H + ] * [Cl − ] ≦ 2.63 * 10 −2 * K It becomes 1 (T) (11). As in the case of obtaining the upper limit, since the water temperature of water and sewage water, industrial water, river water, etc. is 0 to 25 ° C, the value becomes smaller as a result, K 1 (0) = 1.46 * 10 -4 is substituted. [H + ] *
A ≦ 3.84 * 10 -6 - [Cl].
よってpH≦6.15でかつ〔H+〕＊〔Cl-〕≦3.84＊10-6の
条件を満たせば、遊離塩素は常に次亜塩素酸の形態で95
％以上が存在する。したがって、このように調整された
試料水の次亜塩素酸を測定すれば、試料水中の次亜塩素
酸と次亜塩素酸イオンの合計濃度が求まる。Therefore and a pH ≦ 6.15 [H +] * [Cl -] satisfies the condition of ≦ 3.84 * 10 -6, free chlorine is always in the form of hypochlorous acid 95
% Or more exists. Therefore, by measuring the hypochlorous acid in the sample water thus adjusted, the total concentration of hypochlorous acid and hypochlorite ion in the sample water can be obtained.
第４図の実施例では次亜塩素酸の抽出方法としてヘッド
スペース法を示したが、請求項１の発明と同様にこれに
限定されるものではなく、バブリング法を用いてもよ
い。Although the headspace method is shown as the method for extracting hypochlorous acid in the embodiment of FIG. 4, the invention is not limited to this as in the invention of claim 1, and a bubbling method may be used.
この発明によれば、 １）試料水中の次亜塩素酸を気相に移行させて行う遊離
塩素測定装置において、 （１）試料水中の次亜塩素酸をキャリアガス中に移行さ
せる気相抽出手段と、 （２）キャリアガス中に移行した次亜塩素酸を検知して
試料水中の次亜塩素酸濃度〔HOCl〕を測定するIn2O3を
主成分とする金属酸化物半導体式ガス検知手段と、 （３）試料水のpHを検知する手段と、 （４）試料水の温度（Ｔ）を測定する手段と、 （５）次亜塩素酸イオン濃度を〔OCl-〕,K2（Ｔ）を温
度によって決まる酸解離定数とするときに次式 〔OCl-〕＝K2（Ｔ）＊〔HOCl〕＊10pH および〔OCl-〕＋〔HOCl〕の計算を行う演算部、とを備
え、または ２）試料水中の次亜塩素酸を気相に移行させて行う遊離
塩素測定装置において、 （１）試料水中の次亜塩素酸をキャリアガス中に移行さ
せる気相抽出手段と、 （２）キャリアガス中に移行した次亜塩素酸を検知して
試料水中の次亜塩素酸濃度を測定するIn2O3を主成分と
する金属酸化物半導体式ガス検知手段と、 （３）試料水の塩素イオン濃度を〔Cl-〕とするときに
試料水のpHを下記範囲内にする pH調節手段、とを備えるので、 イ）試料水中の次亜塩素酸は汚染を受けることのないIn
2O3を主成分とする金属酸化物半導体式ガスセンサによ
って高信頼性の測定がなされる。In2O3を主成分とする
金属酸化物半導体式ガスセンサで検知されない次亜塩素
酸イオンは試料水のpHと温度をもとにして計算され、こ
れらの結果として遊離塩素を高い信頼性で測定すること
が可能となる。According to the present invention, 1) in a free chlorine measuring apparatus for transferring hypochlorous acid in sample water to a gas phase, (1) gas phase extraction means for transferring hypochlorous acid in sample water into a carrier gas And (2) a metal oxide semiconductor gas detection means containing In 2 O 3 as a main component, which detects hypochlorous acid transferred into a carrier gas to measure a hypochlorous acid concentration [HOCl] in sample water. And (3) means for detecting the pH of the sample water, (4) means for measuring the temperature (T) of the sample water, and (5) the hypochlorite ion concentration as [OCl − ], K 2 (T following equation when) the acid dissociation constant determined by the temperature [OCl -] = K 2 (T) * [HOCl] * 10 pH and [OCl -] + calculator calculating performing the [HOCl], comprises a capital , Or 2) In a free chlorine measuring device which transfers hypochlorous acid in sample water to a gas phase, (1) hypochlorous acid in sample water Metal and vapor extraction means for shifting the carrier gas, mainly composed of In 2 O 3 to measure the concentration of hypochlorous acid in sample water by detecting hypochlorous acid the process proceeds to (2) carrier gas the pH of the sample water into the following ranges when the - the oxide semiconductor type gas detection means, the concentration of chlorine ions (3) sample water [Cl] Since the pH adjusting means is provided, a) hypochlorous acid in the sample water is not contaminated In
Highly reliable measurement is performed by a metal oxide semiconductor gas sensor whose main component is 2 O 3 . Hypochlorite ion, which is not detected by the metal oxide semiconductor gas sensor whose main component is In 2 O 3 , is calculated based on the pH and temperature of the sample water, and as a result, free chlorine can be measured with high reliability. It becomes possible to do.
ロ）試料水のpHが所定範囲に調整されると、遊離塩素の
95％以上が次亜塩素酸となり、半導体式ガスセンサによ
りこれを検知して遊離塩素を高い信頼性で測定すること
ができる。B) When the pH of the sample water is adjusted within the specified range, free chlorine
95% or more becomes hypochlorous acid, and this can be detected by a semiconductor gas sensor to measure free chlorine with high reliability.
【図面の簡単な説明】 第１図は請求項１の発明の実施例に係る遊離塩素測定装
置を示す配置図、第２図は請求項１または２の発明の実
施例に係る装置のうちのIn2O3を主成分とする金属酸化
物半導体式ガスセンサを示し、第２図（ａ）は斜視図、
第２図（ｂ）は断面図、第３図は請求項１の発明の異な
る実施例に係る遊離塩素測定装置を示す配置図、第４図
は請求項２の発明の実施例に係る遊離塩素測定装置を示
す配置図、第５図は試料水pHとHOCl存在割合を示す線図
である。 1:フィルタ、2,3:流量計、4:抽出槽、5:pH計、6:水温
計、7:測定チャンバ、8:エアポンプ、9:演算装置、31:
薬液ポンプ、32:レコーダ。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a layout view showing a free chlorine measuring device according to an embodiment of the invention of claim 1, and FIG. 2 is a device showing an embodiment of the invention of claim 1 or 2. FIG. 2 (a) is a perspective view showing a metal oxide semiconductor type gas sensor containing In 2 O 3 as a main component.
2 (b) is a sectional view, FIG. 3 is a layout showing a free chlorine measuring device according to a different embodiment of the invention of claim 1, and FIG. 4 is a free chlorine according to the embodiment of the invention of claim 2. FIG. 5 is a diagram showing the arrangement of the measuring device, and FIG. 5 is a diagram showing the pH of the sample water and the proportion of HOCl present. 1: Filter, 2, 3: Flow meter, 4: Extraction tank, 5: pH meter, 6: Water temperature meter, 7: Measuring chamber, 8: Air pump, 9: Computing device, 31:
Chemical pump, 32: recorder.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 伊藤 晴夫 神奈川県川崎市川崎区田辺新田１番１号 富士電機株式会社内 (72)発明者 高田 義 大阪府大阪市淀川区三津屋中２丁目５番４ 号 新コスモス電機株式会社内 (72)発明者 酒井 才 大阪府大阪市淀川区三津屋中２丁目５番４ 号 新コスモス電機株式会社内 (72)発明者 青木 豊明 大阪府枚方市楠葉野田３丁目37番32号 (56)参考文献 特開 昭58−169049（ＪＰ，Ａ) 実開 昭55−81759（ＪＰ，Ｕ) ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Haruo Ito 1-1 Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Fuji Electric Co., Ltd. (72) Inventor Yoshitaka Takada 2-5, Mitsuyanaka, Yodogawa-ku, Osaka-shi, Osaka No. 4 Inside New Cosmos Electric Co., Ltd. (72) Inventor Sakai Satoshi 2-5-4 Mitsuyanaka, Yodogawa-ku, Osaka City, Osaka Prefecture (72) Inside New Cosmos Electric Co., Ltd. (72) Toyoaki Aoki, Kusunoki Noda, Hirakata, Osaka Reference 37-32 (56) References JP-A-58-169049 (JP, A) Actual development: S55-81759 (JP, U)
Claims (2)
行う遊離塩素測定装置において、 （１）試料水中の次亜塩素酸をキャリアガス中に移行さ
せる気相抽出手段と、 （２）キャリアガス中に移行した次亜塩素酸を検知し
て、試料水中の次亜塩素酸濃度〔HOCl〕を測定するIn2O
3を主成分とする金属酸化物半導体式ガス検出手段と、 （３）試料水のpHを検知する手段と、 （４）試料水の温度（Ｔ）を測定する手段と、 （５）次亜塩素酸イオン濃度を〔OCl-〕,K2（Ｔ）を温
度によって決まる酸解離定数とするときに次式 〔OCl-〕＝K2（Ｔ）＊〔HOCl〕＊10pH および〔OCl-〕＋〔HOCl〕の計算を行う演算部、とを備
えることを特徴とする遊離塩素測定装置。1. A free chlorine measuring apparatus for transferring hypochlorous acid in sample water to a gas phase, comprising: (1) gas phase extraction means for transferring hypochlorous acid in sample water into a carrier gas; 2) In 2 O which detects the hypochlorous acid transferred to the carrier gas and measures the hypochlorous acid concentration [HOCl] in the sample water.
A metal oxide semiconductor type gas detection means containing 3 as a main component; (3) a means for detecting the pH of the sample water; (4) a means for measuring the temperature (T) of the sample water; the chlorate ion concentration [OCl -], the following equation when the acid dissociation constant determined K 2 (T) is the temperature [OCl -] = K 2 (T) * [HOCl] * 10 pH and [OCl -] A free chlorine measuring device comprising: a calculation unit that calculates + [HOCl].
行う遊離塩素測定装置において、 （１）試料水中の次亜塩素酸をキャリアガス中に移行さ
せる気相抽出手段と、 （２）キャリアガス中に移行した次亜塩素酸を検知し
て、試料水中の次亜塩素酸濃度を測定するIn2O3を主成
分とする金属酸化物半導体式ガス検出手段と、 （３）試料水の塩素イオン濃度を〔Cl-〕とするときに
試料水のpHを下記範囲内にする pH調節手段、とを備えることを特徴とする遊離塩素測定
装置。2. A free chlorine measuring apparatus for transferring hypochlorous acid in sample water to a gas phase, comprising: (1) gas phase extraction means for transferring hypochlorous acid in sample water into a carrier gas; 2) A metal oxide semiconductor type gas detection means containing In 2 O 3 as a main component, which detects hypochlorous acid transferred to a carrier gas to measure the concentration of hypochlorous acid in the sample water, (3) the pH of the sample water into the following ranges when the - chlorine ion concentration of the sample water [Cl] A free chlorine measuring device comprising: a pH adjusting means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17594589A JPH0782005B2 (en) | 1989-07-07 | 1989-07-07 | Free chlorine measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17594589A JPH0782005B2 (en) | 1989-07-07 | 1989-07-07 | Free chlorine measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0341360A JPH0341360A (en) | 1991-02-21 |
| JPH0782005B2 true JPH0782005B2 (en) | 1995-09-06 |
Family
ID=16005003
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17594589A Expired - Lifetime JPH0782005B2 (en) | 1989-07-07 | 1989-07-07 | Free chlorine measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0782005B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111135332A (en) * | 2019-12-23 | 2020-05-12 | 浙江吉叶生物科技有限公司 | Method and system for testing disinfection effect of disinfectant |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58169049A (en) * | 1982-03-31 | 1983-10-05 | Kanegafuchi Chem Ind Co Ltd | Method and apparatus for measuring concentration of substance in liquid |
-
1989
- 1989-07-07 JP JP17594589A patent/JPH0782005B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0341360A (en) | 1991-02-21 |
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