JP4475751B2

JP4475751B2 - Potential detector

Info

Publication number: JP4475751B2
Application number: JP2000191346A
Authority: JP
Inventors: 真一赤沢; 誠斉藤; 裕子立松
Original assignee: DKK TOA Corp
Current assignee: DKK TOA Corp
Priority date: 2000-06-26
Filing date: 2000-06-26
Publication date: 2010-06-09
Anticipated expiration: 2020-06-26
Also published as: JP2002005871A

Description

【０００１】
【発明の属する技術分野】
本発明は電位検出装置に関するものであり、特に有機系汚水の生物処理装置に用いられる曝気槽内の試料の酸化還元電位や、溶存酸素量、あるいはｐＨ値の測定に好適に用いることのできる電位検出装置に関する。
【０００２】
【従来の技術】
下水等の有機性汚水の処理を行うにあたっては、脱窒、脱燐、有害化学物質の除去、希薄濃度排水および高濃度排水の処理等が重要な課題である。近年は、これらの処理を行うに際して、コストやエネルギーの点で優れている微生物を利用した生物処理装置を用いる方法が注目されている。
【０００３】
このような生物処理方法の代表的なものに、活性汚泥のフロック形成能と生化学的酸素要求量（ＢＯＤ）低下能を利用した活性汚泥法がある。活性汚泥法で生物処理を行うシステムには、曝気槽の前半部を嫌気性槽としたＡＯシステム、あるいはＡＯシステムの嫌気性槽と好気性槽の間に無酸素性の脱窒槽を設けたＡ^２Ｏシステムなどが知られている。これらのＡＯシステムやＡ^２Ｏシステムでは、好気性槽の前段に嫌気性槽を設けて、糸状性細菌の生育を阻害して、好気性槽内でのバルキングの発生を防ぐようにしている。
【０００４】
このような生物処理装置の処理能力を表す指針の一つに、曝気槽内の酸化還元電位がある。特に、嫌気性槽では、槽内の酸化還元電位を測定してその測定値に基づいて嫌気性層内に微散気を行ったり、あるいは接触曝気槽から嫌気性槽内に処理水を返送することによって、汚水処理能力を一定に保つようにしている。したがって、曝気槽の処理能力を一定以上のレベルに保つためには、酸化還元電位を所定の目標値に保つべく槽内の試料の酸化還元電位をモニタリングする必要がある。
【０００５】
この嫌気性槽内の酸化還元電位を測定するにあたっては、従来より槽内の嫌気状態を壊さないために長さ１〜２ｍの浸漬型の検出器が用いられている。しかし、嫌気槽内では試料の動きがなく、また試料中の溶存酸素量を低く保つ必要があるため槽内をエアレーションすることができないため、検出器の電極部分に汚れが付着しやすく、検出精度が低下してしまうという問題がある。
【０００６】
この付着した汚れを落とすため、従来は検出器先端の電極部分に水ジェット式洗浄装置、超音波洗浄装置、あるいはセラミックス研磨式洗浄装置などを設けて、連続的にあるいは間欠的に電極の洗浄を行うようにしている。
【０００７】
【発明が解決しようとする課題】
しかしながら、水ジェット方式では、溶存酸素がほぼ飽和状態にある洗浄水を吹き付けて洗浄を行うため、この溶存酸素による酸化還元反応への影響が懸念される。また、セラミックス研磨方式では、試料自体に動きがない嫌気性槽内では逆に電極部に汚れをなすりつけることになり、うまく洗浄できない。また、超音波を用いた洗浄方式も考えられるが、超音波の振動では電極部分に付いた汚れ、特にバルキングを振り落とすには不十分である。このように、従来の技術ではいずれの方法で洗浄しても電極の汚れを十分に汚れを落とすことができず、安定した状態で正確に測定ができないという問題があった。なお、電極を引き上げて洗浄することも行われているが、この方法では電極部分が好気状態にさらされることになるので、洗浄後、安定して測定できる状態に戻るまで時間がかかってしまうという問題がある。
【０００８】
特に酸化還元電位の測定では、金属電極の表面状態（汚れの付着状態）と、試料の溶存酸素とが測定結果に大きく影響するため、試料に流れがなく、溶存酸素の値が低い嫌気性槽内の試料の酸化還元電位を上記の方法で正確かつ安定した状態で連続的にモニタリングを行うのは困難である。
【０００９】
本発明は、これらの問題点を解決して、電極表面に汚れを付着させることなく、正確かつ安定した状態で試料の電位を連続的にモニタリングすることができる電位検出装置を提供することを目的とする。
【００１０】
【課題を解決するための手段】
上記課題を解決するために、本発明の電位検出器は、電極と、当該電極を支持する電極支持体と、前記電極で感知した電位を測定表示する測定表示部とを具え、前記電極を液体試料に接触させて当該試料の電位を検出する電位検出装置において、前記電極と前記液体試料とを相対的に移動させる手段を具えることを特徴とする。
【００１１】
このように、電極と液体試料とを相対的に移動させることによって電極表面に汚れが付着するのを防止することができ、安定かつ正確に試料の電位を連続モニタリングすることが可能となる。
【００１２】
より具体的には、前記電極と液体試料を相対的に移動させる手段が、試料吸排ポンプと、試料吸引路と、電極チャンバと、吸引した試料を元に戻す試料排出路とで構成した閉鎖試料循環系を具え、
試料吸排ポンプで液体試料を吸排して閉鎖試料循環系内で循環させて前記電極と試料の接触を図るようにした。
【００１３】
このように、閉鎖試料循環系を構築して試料を循環移動させて電極と接触させる構成では、試料に流速を与えることによって電極表面に汚れが付着するのを防止できると共に、閉鎖試料循環系中で測定を行っているため、試料中の溶存酸素の量を変化させることがなく電位を検出することができる。この構成は、生物処理装置の嫌気性槽において酸化還元電位を測定する場合に、特に好適に用いることができる。
【００１４】
ここで、前記電極チャンバが、試料流通路に対して斜めに設けた電極支持体保持部を具え、電極支持体先端に設けた電極を前記試料流通路を流れる試料に対向させることが好ましい。
このような構成により、電極表面に汚れが付着しにくくなり、より正確に電位の検出を行うことができる。また、例え電極表面に汚れが付いたとしても、対向して流れてくる試料でこれを除去することができる。
【００１５】
本発明の電位検出装置の他の実施形態においては、前記電極支持体が先端に電極を支持した棒状部材で構成されており、前記電極と液体試料を相対的に移動させる手段が、駆動モータと、前記棒状部材の電極支持側端部と反対側の端部を保持する軸受けとを具え、前記軸受けで保持している前記電極支持体の保持箇所を支点として、前記電極支持体を振り子運動、あるいは歳差運動させるようにしたことを特徴とする。
【００１６】
このように、試料に対して電極を移動させることによっても電極の自浄効果を得ることができる。この場合、電極支持体先端に設置した電極を駆動させる手段を更に設けて、支持体の振り子運動や歳差運動に加えて電極自体を振動させることによって、電極の自浄効果をより一層高めることができる。
【００１７】
なお、本発明の装置に用いる電極はディスク形状とするのが好ましい。生物処理装置の曝気槽等で使用する場合にピン型の電極に比べて汚れが付着しにくくなるためである。
【００１８】
【発明の実施の形態】
以下に図面を参照して本発明の電位検出装置の好適な実施形態について詳細に説明する。
【００１９】
図１は、本発明にかかる電位検出装置の第１実施形態の構成を示す図である。図１において、符号１はスクリューポンプ、２は電極を設置する電極チャンバ、３は吸引ホース、４は排出ホースであり、これらの要素を連結して試料流通路を形成している。符号５は、酸化還元電位測定表示部（図示せず）へ測定信号を送るための配線である。
【００２０】
吸引ホース３とポンプ１との間には抜管付きフランジ１１、ホースバンド１２、およびパッキン１３が配置されており、ホース３とポンプ１との間を水密に保っている。電極チャンバ２とポンプ１との間には、抜管付きフランジ１４と、パッキン１５を設け、また、電極チャンバ２と排出ホース４との間に、継手管１６とホースバンド１７を設けて、電極チャンバ２の上流側端部と下流側端部とをそれぞれ水密に保持している。電極チャンバ２内に電極支持体２１を装填して、この支持体２１の先端に設けた測定電極２２と対照電極２３を試料流通路内に位置させて試料と電極の接触を図る。
【００２１】
嫌気性槽３０内の試料をスクリューポンプ１で採水して試料流通路を循環させることにより、電極チャンバ２内に装填した電極２２、２３に試料を接触させて電位を検出すると共に、試料に適当に流速を与えることによって、電極（特に測定電極２２）の表面に汚れが付着しないようにしている。この試料は、排出ホース４を通って再び嫌気性層３０内に戻り、嫌気性槽３０、吸引ホース３、電極チャンバ２、排出ホース４にて閉ループ測定系が構築されている。
【００２２】
図２は、電極チャンバ２の詳細な構成を示す断面図である。電極チャンバ２は、筒状の試料通路２０１と電極支持部２０２とで構成されており、電極支持部２０２に電極支持体２１を挿入保持する。電極支持部２０２は試料通路２０１に対して下流側に向けて斜めに分岐しており、電極支持部２０２に支持体２１を取り付けたとき、先端に設けた測定電極２２表面が試料の流れに対向して位置するように構成されている。なお、測定電極２２は汚れが付着しにくくなるようにディスク形状とする。
【００２３】
なお、本例では、電極支持部２０２を試料通路に対して斜めに分岐させるようにしたが、試料通路の対向正面に電極支持部を設けて電極を試料の流れに対向させることもできる。
【００２４】
【表１】

【００２５】
上記の表１に、図１に示す本発明の第１実施形態において、ポンプの流量を５〜１５Ｌ／分とした場合の、電極チャンバ２の上流側における試料の線速度(mm/sec）を示す。本願人が実験を行った結果、上流側、すなわち測定電極２２の設定位置Ｐにおいて線速度が３００ｍｍ／分程度あれば、電極に汚れが付着することなく、かつ、安定して電位を測定できることがわかった。従って、電極を常にきれいな状態に保ち、安定して測定を行うためにはポンプの性能と、測定試料の粘性度等を考慮して、最適な径の電極チャンバを用いればよい。
【００２６】
図３は、本発明の電位測定装置の第２実施形態の構成を示す図である。第２実施形態は、電極支持体を棒状にした浸漬型の測定装置であり、支持体先端に測定電極と対照電極を設け、この支持体を試料に浸漬させて測定を行う。ここでは、電極支持体を測定試料内で振り子運動をさせることによって、支持体先端に設けた電極に付着した汚れを落とすようにしている。
【００２７】
測定電極４０および対照電極４１は、棒状の電極支持体４５の先端に支持されており、この支持体４５を測定試料の所定の深さまで挿入して試料の酸化還元電位を測定する。電極支持体４５の手元側の端部は、軸受け４２を介して支持台４３に保持されており、手元側端部を駆動モータ４４にて水平方向に駆動することによって、この軸受け４２の保持箇所を中心にして電極支持体４２を振り子運動させるようにしている。この動きによって電極４０および４１表面の汚れを落とすことができる。
【００２８】
なお、支持体４１先端の電極部にモータ（図示せず）で振動を与えて、より一層洗浄効果を高めるようにしている。
【００２９】
図４は、本発明の電位測定装置の第３実施形態の構成を示す図である。第３実施形態は、第２実施形態と同様に棒状の電極支持体を試料内に浸漬させて測定を行うが、支持体先端に設けた電極を測定試料内で歳差運動をさせることによって、電極に付着した汚れを落とすようにしている。
【００３０】
測定電極５０および対照電極５１を棒状の電極支持体５５の先端に支持して、支持体５５を測定試料の所定の深さまで挿入して試料の酸化還元電位を測定する。電極支持体５５の反対側の端部は、変形自在の軸受け５２を介して支持台５４に固定されており、電極支持体５５の手元側端部を駆動モータ５４によって回転運動させることによって、支持体５１を歳差運動させて、この動きによって電極５０および５１の表面の汚れを落とすようにしている。ここでも、先端の電極部にモータ（図示せず）で振動を与えるようにしている。
【００３１】
なお、第２、第３の実施形態では、電極支持体４５、５５の駆動部を試料外に設けるようにしているが、電極、電極支持体、駆動部ともに試料内に設けるように構成することも可能である。
【００３２】
上述の実施形態では、電極支持体２１の先端に設けた測定電極２２をディスク形状のものとしたが、ピン型のものを用いても良い。ただし、粘性が高い試料や、汚れが付着しやすい試料の電位を測定する場合はディスク形状とするのが好ましい。電極の材質には金またはプラチナを好適に用いることができるが、測定の安定性を考慮すると金を用いることが好ましい。
【００３３】
上述の実施形態では、試料の酸化還元電位の測定を例にとって説明したが、本発明の装置は、これに限らず、ｐＨ値の測定、試料内の溶存酸素量の測定等にも利用することができる。また、上述の実施形態では、嫌気性槽を測定対象としているが、本発明の装置は好気性槽においても好適に利用することができる。
【００３４】
【発明の効果】
上述したとおり、本発明の電位測定装置では、試料と電極を相対的に移動させるようにしているため、電極表面に汚れが付着しにくくなり、正確な測定を行うことができる。エアレーションを行わないため、試料内の溶存酸素の状態を変えることなく電位を測定することが可能であり、溶存酸素が測定に大きく影響する生物処理装置、特に嫌気性槽内の試料の電位を測定する場合に、好適に利用できる。更に、電極を外部に取り出すことなく洗浄できるため、試料の連続モニタリングを行う場合に好適に利用することができる。
【図面の簡単な説明】
【図１】本発明にかかる電位測定装置の第１実施形態の構成を示す図である。
【図２】図１に示す電位測定装置に好適に用いられる電極チャンバの構成を示す図である。
【図３】本発明にかかる電位測定装置の第２実施形態の構成を示す図である。
【図４】本発明にかかる電位測定装置の第３実施形態の構成を示す図である。
【符号の説明】
１スクリューポンプ
２電極チャンバ
３吸引ホース
４排出ホース
５配線
１１、１４抜管付きフランジ
１３、１５パッキン
１２、１７ホースバンド
１６継手管
２１、４５電極支持体
２２、４０、５０測定電極
２３、４１、５１対照電極
３０嫌気性槽
４２、５２軸受け
４３、５３支持台
４４、５４駆動モータ
２０１試料通路
２０２電極支持部
Ｐ電極設定位置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a potential detection device, and in particular, a potential that can be suitably used for measuring the oxidation-reduction potential, dissolved oxygen amount, or pH value of a sample in an aeration tank used in a biological treatment device for organic wastewater. The present invention relates to a detection device.
[0002]
[Prior art]
When treating organic sewage such as sewage, denitrification, dephosphorization, removal of hazardous chemicals, treatment of dilute wastewater and high concentration wastewater are important issues. In recent years, in performing these treatments, a method using a biological treatment apparatus using microorganisms, which is excellent in terms of cost and energy, has attracted attention.
[0003]
A representative example of such a biological treatment method is an activated sludge method that uses the floc-forming ability of activated sludge and the ability to reduce biochemical oxygen demand (BOD). The system that performs biological treatment by the activated sludge method is an AO system in which the first half of the aeration tank is an anaerobic tank, or an anoxic denitrification tank is provided between the anaerobic tank and the aerobic tank of the AO system. ² O systems are known. In these AO systems and A ² O systems, an anaerobic tank is provided in front of the aerobic tank to inhibit the growth of filamentous bacteria and prevent bulking in the aerobic tank.
[0004]
One guideline representing the treatment capacity of such a biological treatment apparatus is the oxidation-reduction potential in the aeration tank. In particular, in an anaerobic tank, the redox potential in the tank is measured and fine aeration is performed in the anaerobic layer based on the measured value, or treated water is returned from the contact aeration tank to the anaerobic tank. Therefore, the wastewater treatment capacity is kept constant. Therefore, in order to keep the processing capacity of the aeration tank at a certain level or higher, it is necessary to monitor the redox potential of the sample in the tank in order to keep the redox potential at a predetermined target value.
[0005]
In measuring the oxidation-reduction potential in the anaerobic tank, an immersion type detector having a length of 1 to 2 m is conventionally used in order not to break the anaerobic state in the tank. However, there is no movement of the sample in the anaerobic tank, and it is necessary to keep the dissolved oxygen amount in the sample low, so it is impossible to aerate the inside of the tank. There is a problem that will decrease.
[0006]
In order to remove this adhered dirt, conventionally, a water jet cleaning device, an ultrasonic cleaning device, or a ceramic polishing cleaning device has been provided on the electrode part at the tip of the detector to clean the electrode continuously or intermittently. Like to do.
[0007]
[Problems to be solved by the invention]
However, in the water jet method, since cleaning is performed by spraying cleaning water in which dissolved oxygen is almost saturated, there is a concern that the dissolved oxygen may affect the oxidation-reduction reaction. Also, in the ceramic polishing method, in an anaerobic tank where the sample itself does not move, dirt is rubbed on the electrode part, so that it cannot be cleaned well. A cleaning method using ultrasonic waves is also conceivable, but ultrasonic vibration is insufficient to shake off dirt on the electrode portion, particularly bulking. As described above, the conventional technique has a problem that the electrode cannot be sufficiently cleaned by any of the cleaning methods, and accurate measurement cannot be performed in a stable state. Although the electrode is lifted and cleaned, this method exposes the electrode part to an aerobic state, and thus it takes time to return to a state where it can be stably measured after cleaning. There is a problem.
[0008]
Especially in the measurement of oxidation-reduction potential, the surface condition of the metal electrode (dirt adhesion state) and the dissolved oxygen of the sample greatly affect the measurement results, so there is no flow in the sample and the anaerobic tank has a low dissolved oxygen value. It is difficult to continuously monitor the redox potential of the sample in the above method in an accurate and stable state.
[0009]
An object of the present invention is to solve these problems and to provide a potential detection device capable of continuously monitoring the potential of a sample in an accurate and stable state without attaching dirt to the electrode surface. And
[0010]
[Means for Solving the Problems]
In order to solve the above problems, an electric potential detector according to the present invention includes an electrode, an electrode support that supports the electrode, and a measurement display unit that measures and displays a potential sensed by the electrode. An electric potential detection apparatus for detecting the electric potential of a sample in contact with the sample is characterized by comprising means for relatively moving the electrode and the liquid sample.
[0011]
In this way, it is possible to prevent dirt from adhering to the electrode surface by relatively moving the electrode and the liquid sample, and it is possible to continuously and accurately monitor the potential of the sample.
[0012]
More specifically, the means for relatively moving the electrode and the liquid sample includes a sample suction / discharge pump, a sample suction path, an electrode chamber, and a sample discharge path for returning the sucked sample to the original position. With a circulatory system,
The liquid sample was sucked and discharged by the sample suction / discharge pump and circulated in the closed sample circulation system so as to contact the electrode and the sample.
[0013]
In this way, in the configuration in which the closed sample circulation system is constructed and the sample is circulated and brought into contact with the electrode, it is possible to prevent dirt from adhering to the electrode surface by giving a flow rate to the sample, and in the closed sample circulation system. Therefore, the potential can be detected without changing the amount of dissolved oxygen in the sample. This configuration can be particularly suitably used when measuring the oxidation-reduction potential in an anaerobic tank of a biological treatment apparatus.
[0014]
Here, it is preferable that the electrode chamber includes an electrode support holding portion provided obliquely with respect to the sample flow path, and an electrode provided at the tip of the electrode support is opposed to the sample flowing through the sample flow path.
With such a configuration, dirt is less likely to adhere to the electrode surface, and the potential can be detected more accurately. Moreover, even if the electrode surface is contaminated, it can be removed by the sample flowing oppositely.
[0015]
In another embodiment of the potential detection device of the present invention, the electrode support is composed of a rod-shaped member that supports an electrode at the tip, and the means for moving the electrode and the liquid sample relatively includes a drive motor, A bearing that holds the end opposite to the electrode support side end of the rod-shaped member, and the electrode support is held by the bearing as a fulcrum, with the electrode support being in a pendulum motion, Alternatively, it is characterized by precession.
[0016]
Thus, the self-cleaning effect of an electrode can be acquired also by moving an electrode with respect to a sample. In this case, it is possible to further enhance the self-cleaning effect of the electrode by further providing means for driving the electrode installed at the tip of the electrode support and vibrating the electrode itself in addition to the pendulum motion and precession motion of the support. it can.
[0017]
The electrodes used in the apparatus of the present invention are preferably disk-shaped. This is because when used in an aeration tank or the like of a biological treatment apparatus, dirt is less likely to adhere compared to a pin-type electrode.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a potential detection device of the present invention will be described in detail with reference to the drawings.
[0019]
FIG. 1 is a diagram showing a configuration of a first embodiment of a potential detection device according to the present invention. In FIG. 1, reference numeral 1 is a screw pump, 2 is an electrode chamber in which an electrode is installed, 3 is a suction hose, and 4 is a discharge hose, and these elements are connected to form a sample flow path. Reference numeral 5 denotes a wiring for sending a measurement signal to an oxidation-reduction potential measurement display unit (not shown).
[0020]
Between the suction hose 3 and the pump 1, a flange 11 with a drawn tube, a hose band 12, and a packing 13 are disposed, and the space between the hose 3 and the pump 1 is kept watertight. Between the electrode chamber 2 and the pump 1, a flange 14 with an extraction pipe and a packing 15 are provided, and between the electrode chamber 2 and the discharge hose 4, a joint pipe 16 and a hose band 17 are provided, The upstream end portion and the downstream end portion 2 are each kept watertight. An electrode support 21 is loaded into the electrode chamber 2, and the measurement electrode 22 and the reference electrode 23 provided at the tip of the support 21 are positioned in the sample flow path to make contact between the sample and the electrode.
[0021]
The sample in the anaerobic tank 30 is sampled with the screw pump 1 and circulated through the sample flow path, whereby the sample is brought into contact with the electrodes 22 and 23 loaded in the electrode chamber 2 and the potential is detected. By applying an appropriate flow rate, dirt is not attached to the surface of the electrode (particularly the measurement electrode 22). This sample returns to the anaerobic layer 30 again through the discharge hose 4, and a closed loop measurement system is constructed by the anaerobic tank 30, the suction hose 3, the electrode chamber 2, and the discharge hose 4.
[0022]
FIG. 2 is a cross-sectional view showing a detailed configuration of the electrode chamber 2. The electrode chamber 2 is composed of a cylindrical sample passage 201 and an electrode support portion 202, and the electrode support 21 is inserted and held in the electrode support portion 202. The electrode support 202 is obliquely branched toward the downstream side with respect to the sample passage 201. When the support 21 is attached to the electrode support 202, the surface of the measurement electrode 22 provided at the tip faces the sample flow. It is configured to be located. Note that the measurement electrode 22 has a disk shape so that dirt is difficult to adhere.
[0023]
In this example, the electrode support portion 202 is branched obliquely with respect to the sample passage. However, an electrode support portion may be provided in front of the sample passage so as to face the sample flow.
[0024]
[Table 1]

[0025]
Table 1 shows the linear velocity (mm / sec) of the sample on the upstream side of the electrode chamber 2 when the flow rate of the pump is 5 to 15 L / min in the first embodiment of the present invention shown in FIG. Show. As a result of the experiment conducted by the present applicant, if the linear velocity is about 300 mm / min on the upstream side, that is, the set position P of the measurement electrode 22, the potential can be measured stably without contamination on the electrode. all right. Accordingly, in order to keep the electrodes clean and perform measurement stably, an electrode chamber having an optimum diameter may be used in consideration of the performance of the pump and the viscosity of the measurement sample.
[0026]
FIG. 3 is a diagram showing the configuration of the second embodiment of the potential measuring apparatus of the present invention. The second embodiment is an immersion type measuring apparatus in which an electrode support is made into a rod shape, and a measurement electrode and a control electrode are provided at the tip of the support, and measurement is performed by immersing this support in a sample. Here, the electrode support is made to move in a pendulum within the measurement sample, so that the dirt attached to the electrode provided at the tip of the support is removed.
[0027]
The measurement electrode 40 and the reference electrode 41 are supported at the tip of a rod-shaped electrode support 45, and the support 45 is inserted to a predetermined depth of the measurement sample to measure the oxidation-reduction potential of the sample. The proximal end of the electrode support 45 is held by a support base 43 via a bearing 42, and the holding portion of the bearing 42 is held by driving the proximal end in the horizontal direction by a drive motor 44. The electrode support 42 is moved in a pendulum manner around the center. By this movement, the surfaces of the electrodes 40 and 41 can be cleaned.
[0028]
The electrode 41 at the tip of the support 41 is vibrated by a motor (not shown) to further enhance the cleaning effect.
[0029]
FIG. 4 is a diagram showing the configuration of the third embodiment of the potential measuring apparatus of the present invention. The third embodiment performs measurement by immersing a rod-shaped electrode support in the sample as in the second embodiment, but by precessing the electrode provided at the tip of the support in the measurement sample, The dirt attached to the electrode is removed.
[0030]
The measurement electrode 50 and the reference electrode 51 are supported on the tip of a rod-shaped electrode support 55, the support 55 is inserted to a predetermined depth of the measurement sample, and the oxidation-reduction potential of the sample is measured. The opposite end of the electrode support 55 is fixed to a support base 54 via a deformable bearing 52, and is supported by rotating the proximal end of the electrode support 55 with a drive motor 54. The body 51 is precessed, and this movement removes dirt on the surfaces of the electrodes 50 and 51. Again, vibration is applied to the tip electrode portion by a motor (not shown).
[0031]
In the second and third embodiments, the drive unit for the electrode supports 45 and 55 is provided outside the sample. However, the electrode, the electrode support, and the drive unit may be provided in the sample. Is also possible.
[0032]
In the above-described embodiment, the measurement electrode 22 provided at the tip of the electrode support 21 is a disk shape, but a pin type may be used. However, in the case of measuring the potential of a sample having a high viscosity or a sample to which dirt is likely to adhere, the disk shape is preferable. Gold or platinum can be suitably used as the material of the electrode, but it is preferable to use gold in consideration of measurement stability.
[0033]
In the above-described embodiment, the measurement of the oxidation-reduction potential of the sample has been described as an example. However, the apparatus of the present invention is not limited to this, and is also used for measuring the pH value, measuring the dissolved oxygen amount in the sample, and the like. Can do. Moreover, in the above-mentioned embodiment, although the anaerobic tank is made into the measuring object, the apparatus of this invention can be utilized suitably also in an aerobic tank.
[0034]
【The invention's effect】
As described above, in the potential measuring device of the present invention, the sample and the electrode are relatively moved, so that dirt hardly adheres to the electrode surface, and accurate measurement can be performed. Since aeration is not performed, the potential can be measured without changing the state of dissolved oxygen in the sample, and the potential of the sample in biological treatment equipment, particularly anaerobic tanks, where dissolved oxygen greatly affects the measurement is measured. In this case, it can be suitably used. Furthermore, since it can wash | clean without taking out an electrode outside, it can utilize suitably when performing continuous monitoring of a sample.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a first embodiment of a potential measuring device according to the present invention.
FIG. 2 is a diagram showing a configuration of an electrode chamber that is preferably used in the potential measuring apparatus shown in FIG. 1;
FIG. 3 is a diagram showing a configuration of a second embodiment of a potential measuring apparatus according to the present invention.
FIG. 4 is a diagram showing a configuration of a third embodiment of a potential measuring apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Screw pump 2 Electrode chamber 3 Suction hose 4 Exhaust hose 5 Wiring 11, 14 Flange 13, 15 Packing pipe 12, 17 Hose band 16 Joint pipe 21, 45 Electrode support 22, 40, 50 Measuring electrode 23, 41, 51 Control electrode 30 Anaerobic tank 42, 52 Bearing 43, 53 Support base 44, 54 Drive motor 201 Sample passage 202 Electrode support part P Electrode setting position

Claims

In a potential detection device comprising an electrode, an electrode support that supports the electrode, and a measurement display unit that measures and displays the potential sensed by the electrode, and detects the potential of the sample by bringing the electrode into contact with a liquid sample ,
Means for relatively moving the electrode and the liquid sample ;
The electrode support is composed of a rod-shaped member that supports an electrode at the tip,
The means for relatively moving the electrode and the liquid sample includes a drive motor and a bearing that holds an end of the rod-shaped member opposite to the electrode supporting side, and is held by the bearing. Using the holding point of the electrode support as a fulcrum, the electrode support is configured to perform a pendulum motion,
And a means for vibrating the electrode provided at the tip of the electrode support .

In a potential detection apparatus comprising an electrode, an electrode support that supports the electrode, and a measurement display unit that measures and displays the potential sensed by the electrode, and detects the potential of the sample by bringing the electrode into contact with a liquid sample ,
Means for relatively moving the electrode and the liquid sample;
The electrode support is composed of a rod-shaped member that supports an electrode at the tip,
The means for relatively moving the electrode and the liquid sample includes a drive motor and a bearing that holds an end of the rod-shaped member opposite to the electrode supporting side, and is held by the bearing. It is configured to precess the electrode support with the holding point of the electrode support as a fulcrum,
And a means for vibrating the electrode provided at the tip of the electrode support.

The potential detection device according to claim 1, wherein the electrode has a disk shape.

The potential detection apparatus according to claim 1, wherein the liquid sample contains an anaerobic microorganism.