JP5077065B2 - Continuous treatment apparatus and continuous treatment method for waste water containing COD component - Google Patents

Continuous treatment apparatus and continuous treatment method for waste water containing COD component Download PDF

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JP5077065B2
JP5077065B2 JP2008134421A JP2008134421A JP5077065B2 JP 5077065 B2 JP5077065 B2 JP 5077065B2 JP 2008134421 A JP2008134421 A JP 2008134421A JP 2008134421 A JP2008134421 A JP 2008134421A JP 5077065 B2 JP5077065 B2 JP 5077065B2
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oxidant
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JP2009006316A (en
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洋平 冨田
俊明 局
知道 中村
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JFE Steel Corp
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Description

本発明は、ＣＯＤ成分を含有する廃水の連続処理装置および方法に関するものであり、特に、処理すべき廃水中のＣＯＤ濃度が大きく変動した場合であっても、タイムラグが少なく、ＣＯＤ濃度を排水基準以下の適正範囲内に安定させることができるイオウ系廃水の連続処理装置および連続処理方法に関するものである。   The present invention relates to a continuous treatment apparatus and method for wastewater containing a COD component, and in particular, even when the COD concentration in the wastewater to be treated fluctuates greatly, the time lag is small and the COD concentration is determined based on the drainage standard. The present invention relates to a continuous treatment apparatus and a continuous treatment method for sulfur wastewater that can be stabilized within the following appropriate range.

ＣＯＤ成分を含有する廃水処理には従来から酸化剤が広く用いられており、酸化剤の注入量制御に関しては、例えば、特許文献１には酸化剤として過酸化水素を用い、ＪＩＳ Ｋ０１０２：１９９８に規定する方法に準拠して測定した廃水のＣＯＤＭｎ濃度値に対して過酸化水素を０．５〜５０倍添加し、かつ紫外線を照射して廃水処理する方法が開示されている。
特開平８−１４１５８１号公報 Conventionally, an oxidizing agent has been widely used for the treatment of wastewater containing a COD component. Regarding control of the injection amount of the oxidizing agent, for example, Patent Document 1 uses hydrogen peroxide as an oxidizing agent, and JIS K0102: 1998. Disclosed is a method of treating wastewater by adding 0.5 to 50 times the hydrogen peroxide to the COD Mn concentration value measured in accordance with the prescribed method and irradiating with ultraviolet rays.
Japanese Patent Laid-Open No. 8-141581

また、特許文献２には、酸化剤として過酸化水素とオゾンの双方を用い、第１工程出口および／または第２工程出口の被処理水中の溶存オゾン濃度が実験的・経験的に算出した溶存オゾン濃度の目標値である０．１〜１０ｍｇ／Ｌとなるようオゾンを添加する２段のフィードバック制御による廃水処理方法が開示されている。
特開平１１−１０１７１号公報 Further, Patent Document 2 uses both hydrogen peroxide and ozone as oxidizing agents, and the dissolved ozone concentration calculated in the treated water at the first process outlet and / or second process outlet is experimentally and empirically calculated. A wastewater treatment method by two-stage feedback control in which ozone is added so as to be 0.1 to 10 mg / L that is a target value of ozone concentration is disclosed.
Japanese Patent Laid-Open No. 11-10171

しかし、特許文献１に記載の方法は、処理水質の分析を行っていないため、廃水のＣＯＤ濃度が急激に変動した場合に、ＣＯＤ濃度を排水基準以下に抑制する手段がない。また、特許文献２に記載の２段のフィードバック制御による方法は、流入する廃水のＣＯＤ濃度が大きく変動した場合に、フィードバック制御だけではタイムラグが生じて迅速にＣＯＤ濃度を排水基準以下に制御することができず、オゾン添加量に一時的に過不足が生じるという問題があった。   However, since the method described in Patent Document 1 does not analyze the quality of the treated water, there is no means for suppressing the COD concentration below the drainage standard when the COD concentration of wastewater fluctuates rapidly. Further, in the method based on the two-stage feedback control described in Patent Document 2, when the COD concentration of the inflowing wastewater largely fluctuates, a time lag occurs only with the feedback control, and the COD concentration is quickly controlled below the drainage standard. There was a problem that the amount of ozone added temporarily excessively or insufficiently.

本発明の目的は、処理すべき廃水中に所要量の酸化剤を、少なくとも２段の異なるフィードフォワード制御により決定することで、処理すべき廃水中のＣＯＤ濃度が大きく変動した場合であっても、タイムラグが少なく、ＣＯＤ濃度を排水基準以下の適正範囲内に安定させることができるイオウ系廃水の連続処理装置および連続処理方法を提供することにある。   The object of the present invention is to determine the required amount of oxidant in the wastewater to be treated by at least two different feedforward controls, so that even if the COD concentration in the wastewater to be treated varies greatly. Another object of the present invention is to provide a continuous treatment apparatus and a continuous treatment method for sulfur-based wastewater that have a small time lag and can stabilize the COD concentration within an appropriate range below the drainage standard.

上記目的を達成するため、本発明の要旨構成は以下の通りである。
（１）ＣＯＤ成分を含有する廃水を流入させる第１流入口と前記廃水の処理水である１次処理水を流出させる第１流出口とを有する第１処理槽、前記第１流入口の上流側に設けられた、廃水のＣＯＤ濃度と相関関係を有する第１の物性値を測定するＵＶ計からなる第１モニタリング手段、前記第１処理槽へ第１酸化剤を添加する第１酸化剤注入手段、および、前記第１物性値から前記第１モニタリング手段で予測した第１ＣＯＤ濃度予測値に基づいて前記第１処理槽へ添加する第１酸化剤の添加量を決定し、かつ前記第１酸化剤注入手段による前記第１処理槽への第１酸化剤の添加量を制御する第１制御手段を有する１つの前処理系装置、ならびに前記第１処理槽の第１流出口から流出する１次処理水を流入させる第２流入口と前記１次処理水の処理水である２次処理水を流出させる第２流出口とを有する第２処理槽、前記第２流入口の上流側に設けられた、１次処理水のＣＯＤ濃度を測定する１台または複数台のＣＯＤ計からなる第２モニタリング手段、前記第２処理槽へ第２酸化剤を添加する第２酸化剤注入手段、および、前記第２モニタリング手段で測定した第２ＣＯＤ濃度測定値に基づいて前記第２処理槽へ添加する第２酸化剤の添加量を決定し、かつ前記第２酸化剤注入手段による前記第２処理槽への第２酸化剤の添加量を制御する第２制御手段を有する少なくとも１つの後処理系装置を有することを特徴とするＣＯＤ成分を含有する廃水の連続処理装置。In order to achieve the above object, the gist of the present invention is as follows.
(1) A first treatment tank having a first inlet through which waste water containing a COD component flows in and a first outlet through which primary treated water that is treated water of the waste water flows out, upstream of the first inlet. A first monitoring means comprising a UV meter for measuring a first physical property value having a correlation with the COD concentration of wastewater provided on the side, a first oxidant injection for adding a first oxidant to the first treatment tank And an amount of the first oxidant added to the first treatment tank based on the first COD concentration predicted value predicted by the first monitoring means from the first physical property value, and the first oxidation One pretreatment system device having first control means for controlling the amount of the first oxidizing agent added to the first treatment tank by the agent injection means, and the primary flowing out from the first outlet of the first treatment tank A second inlet through which treated water flows and the primary treatment The second treatment tank having a second outlet for discharging the treated water at a secondary treated water, wherein provided upstream of the second inlet, one measures the COD concentration of the primary treated water or Based on a second monitoring means comprising a plurality of COD meters, a second oxidizing agent injection means for adding a second oxidizing agent to the second treatment tank, and a second COD concentration measurement value measured by the second monitoring means. Second control means for determining an addition amount of the second oxidant to be added to the second treatment tank and controlling an addition amount of the second oxidant to the second treatment tank by the second oxidant injection means; A continuous treatment apparatus for wastewater containing a COD component, comprising at least one aftertreatment system apparatus.

（２）ＣＯＤ成分を含有する廃水のＣＯＤ濃度と一次比例の相関関係を有する第１の物性値をＵＶ計で測定し、この測定値から予測した第１ＣＯＤ濃度予測値に基づいて目標ＣＯＤ濃度にするために必要な第１酸化剤の添加量を決定し、決定された量の第１酸化剤を前記廃水に添加して１次処理水とする、フィードフォワード制御による１つの前処理工程と、前記１次処理水のＣＯＤ濃度をＣＯＤ計で測定し、この測定した第２ＣＯＤ濃度測定値に基づいて目標ＣＯＤ濃度にするために必要な第２酸化剤の添加量を決定し、決定された量の第２酸化剤を前記１次処理水に添加して２次処理水とする、フィードフォワード制御による少なくとも１つの後処理工程とを有することを特徴とするＣＯＤ成分を含有する廃水の処理方法。( 2 ) The first physical property value having a linear proportional correlation with the COD concentration of the wastewater containing the COD component is measured with a UV meter, and the target COD concentration is obtained based on the predicted first COD concentration value predicted from the measured value. A pre-treatment step by feedforward control that determines the amount of the first oxidant necessary for the addition, and adds the determined amount of the first oxidant to the wastewater to form primary treated water; The COD concentration of the primary treated water is measured with a COD meter, and the addition amount of the second oxidant necessary for achieving the target COD concentration is determined based on the measured second COD concentration measurement value, and the determined amount A method for treating wastewater containing a COD component, comprising: adding at least one post-treatment step by feedforward control to add secondary oxidant to secondary treated water.

（３）前記第２ＣＯＤ濃度測定値が、２台以上のＣＯＤ計で所定時間ずらして測定し
た値であることを特徴とする上記（２）に記載のＣＯＤ成分を含有する廃水の連続処理
方法。( 3 ) The continuous treatment method for wastewater containing a COD component according to ( 2 ) above, wherein the second COD concentration measurement value is a value measured by shifting a predetermined time with two or more COD meters.

（１６）前記廃水がイオウ系の廃水であることを特徴とする上記（８）〜（１５）のいずれか一に記載のＣＯＤ成分を含有する廃水の連続処理方法。   (16) The continuous treatment method for wastewater containing a COD component according to any one of (8) to (15) above, wherein the wastewater is sulfur-based wastewater.

本発明によれば、処理すべき廃水中に所要量の酸化剤を、少なくとも２段の異なるフィードフォワード制御により決定することで、処理すべき廃水中のＣＯＤ濃度が大きく変動した場合であっても、タイムラグが少なく、ＣＯＤ濃度を排水基準以下の適正範囲内に安定させることができるイオウ系廃水の連続処理装置および連続処理方法の提供が可能になる。   According to the present invention, even if the COD concentration in the wastewater to be treated varies greatly by determining the required amount of oxidizer in the wastewater to be treated by at least two different feedforward controls. Therefore, it is possible to provide a continuous treatment apparatus and a continuous treatment method for sulfur-based wastewater with a small time lag and capable of stabilizing the COD concentration within an appropriate range below the drainage standard.

以下、本発明の実施形態を詳細に説明する。
図１は、本発明に係るＣＯＤ成分を含有する廃水の連続処理装置の実施形態を示す工程図である。ＣＯＤ成分を含有する廃水は、イオウ系廃水であるのが好ましい。図１に示す装置は、前処理系装置Iと後処理系装置IIとで主に構成されている。 Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a process diagram showing an embodiment of a continuous treatment apparatus for wastewater containing a COD component according to the present invention. The waste water containing the COD component is preferably a sulfur waste water. The apparatus shown in FIG. 1 is mainly composed of a pre-processing system apparatus I and a post-processing system apparatus II.

前処理系装置Iは、第１処理槽３と、第１モニタリング手段５と、第１酸化剤注入手段７と、第１制御手段６とで主に構成されている。
第１処理槽３は、ＣＯＤ成分を含有する廃水１を流入させる第１流入口２と前記廃水の処理水である１次処理水９を流出させる第１流出口４とを有する。
第１モニタリング手段５は、第１流入口２の上流側に設けられた廃水１のＣＯＤ濃度と相関関係を有する第１の物性値を測定する。
第１酸化剤注入手段７は、第１処理槽３へ第１酸化剤を添加する。第１酸化剤注入手段７としては、例えば、ポンプが挙げられる。
第１制御手段６は、第１物性値から第１モニタリング手段５で予測した第１ＣＯＤ濃度予測値に基づいて第１処理槽３へ添加する第１酸化剤の添加量を決定し、かつ第１酸化剤注入手段７による第１処理槽３への第１酸化剤の添加量を決定された添加量となる様に制御するフィードフォワード制御である。 The pretreatment system apparatus I is mainly composed of a first treatment tank 3, first monitoring means 5, first oxidant injection means 7, and first control means 6.
The 1st processing tank 3 has the 1st inflow port 2 which flows in the waste water 1 containing a COD component, and the 1st outflow port 4 which flows out the primary treated water 9 which is the treated water of the said waste water.
The first monitoring means 5 measures a first physical property value having a correlation with the COD concentration of the wastewater 1 provided on the upstream side of the first inflow port 2.
The first oxidant injection means 7 adds the first oxidant to the first treatment tank 3. An example of the first oxidant injection means 7 is a pump.
The first control means 6 determines the addition amount of the first oxidant to be added to the first treatment tank 3 based on the first COD concentration predicted value predicted by the first monitoring means 5 from the first physical property value, and the first This is feedforward control for controlling the amount of the first oxidant added to the first treatment tank 3 by the oxidant injection means 7 so as to be the determined amount added.

後処理系装置IIは、第２処理槽１１と、第２モニタリング手段１３と、第２酸化剤注入手段１５と、第２制御手段１４とで主に構成されている。
第２処理槽１１は、第１処理槽３の第１流出口４から流出する１次処理水９を流入させる第２流入口１０と１次処理水９の処理水である２次処理水１６を流出させる第２流出口１２とを有する。
第２モニタリング手段１３は、第２流入口１０の上流側に設けられた１次処理水９のＣＯＤ濃度を測定する。
第２酸化剤注入手段１５は、第２処理槽１１へ第２酸化剤を添加する。第２酸化剤注入手段１５としては、例えば、ポンプが挙げられる。
第２制御手段１４は、第２モニタリング手段１３で測定した第２ＣＯＤ濃度測定値に基づいて第２処理槽１１へ添加する第２酸化剤の添加量を決定し、かつ第２酸化剤注入手段１５による第２処理槽１１への第２酸化剤の添加量を決定された添加量となる様に制御するフィードフォワード制御である。 The post-treatment system apparatus II is mainly composed of a second treatment tank 11, second monitoring means 13, second oxidant injection means 15, and second control means 14.
The second treatment tank 11 is a second treated water 16 that is treated water of the second treated inlet 10 and the first treated water 9 for flowing in the first treated water 9 flowing out from the first outlet 4 of the first treating tank 3. And a second outlet 12 through which the gas flows out.
The second monitoring unit 13 measures the COD concentration of the primary treated water 9 provided on the upstream side of the second inlet 10.
The second oxidant injection means 15 adds the second oxidant to the second treatment tank 11. An example of the second oxidant injection means 15 is a pump.
The second control means 14 determines the amount of the second oxidant added to the second treatment tank 11 based on the second COD concentration measurement value measured by the second monitoring means 13, and the second oxidant injection means 15. Is a feedforward control for controlling the amount of the second oxidizing agent added to the second treatment tank 11 to be the determined amount added.

本発明によるＣＯＤ成分を含有する廃水の連続処理装置は、追加処理系装置IIをさらに有するのが好ましい。
追加処理系装置IIIは、第３モニタリング手段１７と、第３制御手段１８とで主に構成されている。
第３モニタリング手段１７は、最も後段に位置する後処理系装置IIの第２処理槽１１の第２流出口１２から流出する２次処理水１６のＣＯＤ濃度と所定の関係を有する第２の物性値を測定する。
第３制御手段１８は、第３モニタリング手段１７で測定した第２物性測定値に基づいて、最も後段に位置する後処理系装置IIの第２酸化剤注入手段１５による第２処理槽１１への第２酸化剤の添加量を制御するフィードバック制御、例えばＰＩＤ制御である。 The continuous treatment apparatus for wastewater containing a COD component according to the present invention preferably further includes an additional treatment system apparatus II.
The additional processing system apparatus III is mainly composed of third monitoring means 17 and third control means 18.
The third monitoring means 17 has a second physical property having a predetermined relationship with the COD concentration of the secondary treated water 16 flowing out from the second outlet 12 of the second treatment tank 11 of the post-treatment system apparatus II located at the most subsequent stage. Measure the value.
Based on the second physical property measurement value measured by the third monitoring means 17, the third control means 18 is supplied to the second treatment tank 11 by the second oxidant injection means 15 of the post-treatment system apparatus II located at the most rear stage. Feedback control for controlling the amount of the second oxidant added, for example, PID control.

第１酸化剤および第２酸化剤としては、例えば、次亜塩素酸ナトリウム水溶液、オゾン、過酸化水素等が挙げられるが、特に、反応速度が速く、大容量の反応槽を必要としない点から、次亜塩素酸ナトリウム水溶液であるのが好ましい。
また、次亜塩素酸ナトリウムの濃度は、適切な反応速度を確保するために２〜１５質量％とすることが好ましい。さらに好ましいのは５〜１２質量％である。 Examples of the first oxidizing agent and the second oxidizing agent include sodium hypochlorite aqueous solution, ozone, hydrogen peroxide, and the like. In particular, the reaction rate is fast and a large-capacity reaction tank is not required. A sodium hypochlorite aqueous solution is preferable.
Moreover, it is preferable that the density | concentration of sodium hypochlorite shall be 2-15 mass% in order to ensure a suitable reaction rate. More preferred is 5 to 12% by mass.

第１モニタリング手段５は、ＵＶ計である。ＵＶ計は、ＣＯＤ成分が紫外領域に吸収光を有するという特性から、吸光度とＣＯＤ濃度値に線形の相関関係があることを利用して、吸光度の測定値からＣＯＤ濃度値を予測することができ、比較的測定時間が短く、連続測定が可能である。The first monitoring means 5 is a UV meter . The UV meter can predict the COD concentration value from the measured value of absorbance by utilizing the fact that the COD component has absorption light in the ultraviolet region and utilizing the linear correlation between the absorbance and the COD concentration value. The measurement time is relatively short and continuous measurement is possible.

第２モニタリング手段１３は、１台または複数台のＣＯＤ計である。ＣＯＤ計は、ＪＩＳ Ｋ０１０２：１９９８に定められた方法、すなわち、試料（被処理水）に規定量の過マンガン酸カリウム、硫酸および硝酸銀を加え、沸騰水浴中で３０分間反応させたときに消費された過マンガン酸カリウム量から、酸素要求量（ＣＯＤ）を高精度で測定することができる。これは、１回の測定時間が約１時間と比較的長い測定時間となる。The second monitoring means 13 is one or a plurality of COD meters . The COD meter is consumed by the method specified in JIS K0102: 1998, that is, when a specified amount of potassium permanganate, sulfuric acid and silver nitrate is added to a sample (treated water) and reacted in a boiling water bath for 30 minutes. From the amount of potassium permanganate, the oxygen demand (COD) can be measured with high accuracy. This is a relatively long measurement time of about 1 hour for one measurement time.

第３モニタリング手段１７は、ＯＲＰ計および／または残留塩素計であるのが好ましい。
ＯＲＰ計は、金属電極（金、白金など）をセンサーとして用い、被処理水中の酸化還元電位を測定するものである。比較的測定時間が短く、連続的に予測することができる。また、ＯＲＰ計で測定した酸化還元電位は、ＣＯＤ濃度と所定の関係を有するので最終の後処理系装置の酸化剤添加へのフィードバックのためのモニタリング手段として好ましい。
残留塩素計は、酸化剤として次亜塩素酸ナトリウムを用いる場合に使用できる。残留した酸化剤である残留塩素濃度はＣＯＤ濃度と所定の関係を有する。
残留塩素計としては、以下の２つの方法が挙げられる。
１）ＤＰＤ試薬と混合して、５２８ｎｍの吸光度を測定することにより、残留塩素濃度を予測する方法。
２）ヨウ化カリウムを加え塩素とヨウ化カリウムを反応させ、ヨウ素を遊離させた後に、この遊離したヨウ素を還元剤で滴定し、この滴定した溶液に電極を浸したとき、残留塩素（酸化剤）がある場合には電流が流れ、残留塩素濃度の低下に伴い電流値も低下するという現象を利用し、電流の低下が起こらなくなるまでに要した還元剤の添加量を用いて、残留塩素濃度を測定する方法。
残留塩素計による１回の予測時間は、５分と短時間であるのが特徴である。したがって残留塩素計は最終の後処理系装置の酸化剤添加へのフィードバックのためのモニタリング手段として好ましい。 The third monitoring means 17 is preferably an ORP meter and / or a residual chlorine meter.
The ORP meter uses a metal electrode (gold, platinum, etc.) as a sensor and measures the oxidation-reduction potential in the water to be treated. The measurement time is relatively short and prediction can be made continuously. Further, the oxidation-reduction potential measured with the ORP meter has a predetermined relationship with the COD concentration, and therefore is preferable as a monitoring means for feedback to the addition of the oxidizing agent in the final post-treatment system.
The residual chlorine meter can be used when sodium hypochlorite is used as the oxidizing agent. The residual chlorine concentration which is the remaining oxidizing agent has a predetermined relationship with the COD concentration.
As the residual chlorine meter, the following two methods can be mentioned.
1) A method for predicting the residual chlorine concentration by mixing with a DPD reagent and measuring the absorbance at 528 nm.
2) After adding potassium iodide to react chlorine and potassium iodide to liberate iodine, titrate the liberated iodine with a reducing agent, and immerse the electrode in the titrated solution to obtain residual chlorine (oxidant) ), The current flows and the current value decreases as the residual chlorine concentration decreases. Using the amount of reducing agent added until the current does not decrease, the residual chlorine concentration How to measure.
One prediction time by the residual chlorine meter is characterized by being as short as 5 minutes. Therefore, the residual chlorine meter is preferable as a monitoring means for feedback to the oxidizer addition of the final aftertreatment system.

次に、本発明に係るＣＯＤ成分を含有する廃水の連続処理方法の実施形態について、イオウ系廃水を連続処理する場合を例として説明する。   Next, an embodiment of a continuous treatment method for wastewater containing a COD component according to the present invention will be described by taking as an example the case of continuously treating sulfur wastewater.

第２モニタリング手段１３は、１台または複数台のＣＯＤ計である。ＣＯＤ計は、ＪＩＳ Ｋ０１０２：１９９８に定められた方法、すなわち、試料（被処理水）に規定量の過マンガン酸カリウム、硫酸および硝酸銀を加え、沸騰水浴中で３０分間反応させたときに消費された過マンガン酸カリウム量から、酸素要求量（ＣＯＤ）を高精度で測定することができる。これは、１回の測定時間が約１時間と比較的長い測定時間となる。The second monitoring means 13 is one or a plurality of COD meters . The COD meter is consumed by the method specified in JIS K0102: 1998, that is, when a specified amount of potassium permanganate, sulfuric acid and silver nitrate is added to a sample (treated water) and reacted in a boiling water bath for 30 minutes. From the amount of potassium permanganate, the oxygen demand (COD) can be measured with high accuracy. This is a relatively long measurement time of about 1 hour for one measurement time.

前記１次処理水９は第２流入口１０から第２処理槽１１内へ流入する。第２流入口１０の上流側を流れる１次処理水９の一部を採取し、第２モニタリング手段１３により１次処理水９のＣＯＤ濃度を測定する。次に、この第２ＣＯＤ濃度測定値に基づいて目標ＣＯＤ濃度値にするために必要な第２酸化剤の添加量を決定し、決定された量の第２酸化剤を第２処理槽１１内の１次処理水９に添加する。このようにして２次処理水とするフィードフォワード制御による少なくとも１つの後処理工程を有する。第２酸化剤は酸化剤貯留手段８に保管されている。第２注入手段１５により前記第２酸化剤と１次処理水９とを第２処理槽１１内で混合して２次処理水１６を得、該２次処理水１６が第２処理槽１１の第２流出口１２より流出する。   The primary treated water 9 flows into the second treatment tank 11 from the second inlet 10. A part of the primary treated water 9 flowing upstream from the second inlet 10 is collected, and the COD concentration of the primary treated water 9 is measured by the second monitoring means 13. Next, the addition amount of the second oxidant necessary for achieving the target COD concentration value is determined based on the second COD concentration measurement value, and the determined amount of the second oxidant is stored in the second treatment tank 11. Add to primary treated water 9. Thus, it has at least 1 post-processing process by feedforward control made into secondary treated water. The second oxidant is stored in the oxidant storage means 8. The second injection means 15 mixes the second oxidant and the primary treated water 9 in the second treatment tank 11 to obtain the secondary treated water 16, and the secondary treated water 16 is added to the second treatment tank 11. It flows out from the second outlet 12.

最も後段に位置する後処理工程の２次処理水１６のＣＯＤ濃度と所定の関係を有する第２物性値を測定し、この測定した第２物性測定値と目標ＣＯＤ濃度との関係に基づいて最も後段に位置する後処理工程の第２酸化剤注入手段１５による第２処理槽１１内の１次処理水９への第２酸化剤の添加量を制御する、フィードバック制御による追加処理工程をさらに有するのが好ましい。ここで、後処理工程を複数段有する場合、追加処理工程において制御される第２酸化剤は、最も後段に位置する第２処理槽１１内の１次処理水９に添加するものであるが、この１次処理水は、最も後段に位置する後処理工程より前段の後処理工程により順次処理された処理水であって、便宜上、１次処理水と称するものである。   The second physical property value having a predetermined relationship with the COD concentration of the secondary treated water 16 in the post-treatment step located in the most subsequent stage is measured, and the most based on the relationship between the measured second physical property measured value and the target COD concentration. It further has an additional processing step by feedback control for controlling the amount of the second oxidant added to the primary treated water 9 in the second treatment tank 11 by the second oxidant injection means 15 of the post-treatment step located in the subsequent stage. Is preferred. Here, in the case of having a plurality of post-treatment steps, the second oxidant controlled in the additional treatment step is added to the primary treatment water 9 in the second treatment tank 11 located at the most subsequent stage, This primary treated water is treated water that has been sequentially treated in the post-treatment process preceding the post-treatment process located in the most subsequent stage, and is referred to as primary treated water for convenience.

第１酸化剤および第２酸化剤としては、例えば、次亜塩素酸ナトリウム水溶液、オゾン、過酸化水素等が挙げられるが、特に、反応速度が速く、大容量の反応槽を必要としない点から、次亜塩素酸ナトリウム水溶液であるのが好ましい。
また、次亜塩素酸ナトリウムの濃度は、適切な反応速度を確保するために２〜１５質量％とすることが好ましい。さらに好ましいのは５〜１２質量％である。 Examples of the first oxidizing agent and the second oxidizing agent include sodium hypochlorite aqueous solution, ozone, hydrogen peroxide, and the like. In particular, the reaction rate is fast and a large-capacity reaction tank is not required. A sodium hypochlorite aqueous solution is preferable.
Moreover, it is preferable that the density | concentration of sodium hypochlorite shall be 2-15 mass% in order to ensure a suitable reaction rate. More preferred is 5 to 12% by mass.

第１ＣＯＤ濃度予測値は、ＵＶ計によって予測した値である。ＵＶ計は比較的短時間で測定でき、ＣＯＤ濃度が急激に変動した場合にもモニタリングできるからである。The first COD concentration predicted value is a value predicted by a UV meter . This is because the UV meter can measure in a relatively short time and can monitor even when the COD concentration fluctuates rapidly.

第２ＣＯＤ濃度測定値は、ＣＯＤ計によって測定した値である。ＣＯＤ計は測定に比較的長時間を要するが高精度であり、第２処理槽で確実に処理するために必要な値となるからである。The second COD concentration measurement value is a value measured by a COD meter . This is because the COD meter requires a relatively long time for measurement but is highly accurate and has a value necessary for reliable processing in the second processing tank.

第２ＣＯＤ濃度測定値は、２台以上のＣＯＤ計で所定時間ずらして測定した値であるのが好ましい。２台以上のＣＯＤ計で測定することにより、より精密なＣＯＤ濃度の測定が可能となるからである。   The second COD concentration measurement value is preferably a value measured by shifting by a predetermined time with two or more COD meters. This is because a more precise measurement of COD concentration is possible by measuring with two or more COD meters.

第２物性測定値はＯＲＰ計および／または残留塩素計で測定した値であるのが好ましい。これらの値は連続的にモニタリング可能であり、最終処理として酸化剤添加へのフィードバックが可能となるからである。   The second physical property measurement value is preferably a value measured with an ORP meter and / or a residual chlorine meter. This is because these values can be continuously monitored, and feedback to the addition of the oxidizing agent can be performed as a final treatment.

第２物性測定値の測定にＯＲＰ計と残留塩素計を用いる場合、測定した残留塩素濃度値と目標ＣＯＤ濃度との関係に基づいて最も後段に位置する後処理工程の第２酸化剤注入手段による第２処理槽内の１次処理水への第２酸化剤の添加量を制御することが好ましい。   When an ORP meter and a residual chlorine meter are used to measure the second physical property measurement value, the second oxidant injection means in the post-processing step located at the most subsequent stage based on the relationship between the measured residual chlorine concentration value and the target COD concentration It is preferable to control the amount of the second oxidizing agent added to the primary treated water in the second treatment tank.

前記第２物性測定値の測定に残留塩素計を用いる場合は、第２酸化剤として、例えば、次亜塩素酸ナトリウム溶液のような塩素含有酸化剤を用いることが前提となるが、この場合は、残留塩素計で測定した２次処理水１６の残留塩素濃度が、設定した残留塩素濃度範囲よりも低い場合には第２酸化剤の添加量を増加させ、前記残留塩素濃度範囲よりも高い場合には第２酸化剤の添加量を減少させる。また、前記第２物性測定値の測定にＯＲＰ計を用いる場合、該ＯＲＰ計で測定した２次処理水１６の酸化還元電位が、設定した酸化還元電位範囲よりも低い場合には第２酸化剤の添加量を増加させ、前記酸化還元電位範囲よりも高い場合には第２酸化剤の添加量を減少させる。さらに、前記第２物性測定値の測定にＯＲＰ計と残留塩素計の双方を用いる場合、前記残留塩素計で測定した２次処理水１６の残留塩素濃度に応じて制御することが好ましい。 When a residual chlorine meter is used for measurement of the second physical property measurement value, it is assumed that a chlorine-containing oxidizing agent such as a sodium hypochlorite solution is used as the second oxidizing agent. When the residual chlorine concentration of the secondary treated water 16 measured by the residual chlorine meter is lower than the set residual chlorine concentration range, the amount of addition of the second oxidant is increased and is higher than the residual chlorine concentration range. The amount of the second oxidant added is decreased. When an ORP meter is used to measure the second physical property measurement value, the second oxidizing agent is used when the redox potential of the secondary treated water 16 measured by the ORP meter is lower than the set redox potential range. The amount of the second oxidant is decreased when the amount is higher than the range of the oxidation-reduction potential. Furthermore, when using both an ORP meter and a residual chlorine meter for the measurement of the second physical property measurement value, it is preferable to control according to the residual chlorine concentration of the secondary treated water 16 measured by the residual chlorine meter.

次に、ＣＯＤモニタリング手段による測定値の相関関係について説明する。
図２は、イオウ系廃水におけるＵＶ計の測定値（２５４ｎｍでの吸光度）とＣＯＤ計による測定値の相関を示す。廃水によって若干比例定数は異なるものの一次比例の相関が得られていることがわかる。
また、図３はＵＶ計の測定値（２５４ｎｍでの吸光度）とチオ硫酸イオン濃度の相関を示し、図４はＵＶ計の測定値（２５４ｎｍでの吸光度）と硫化物イオン濃度の相関を示す。これらの図より、両者共に一次比例の関係があることがわかる。しかし、硫化物イオンとチオ硫酸イオンの組成が変化すると、ＵＶ計の測定値とＣＯＤ計による測定値が一次比例関係からずれることおよび塩素が存在すると塩素がＵＶ計で検出され、誤差を生じるという特徴を考慮し、後処理槽への流入水である１次処理水を測定する第２モニタリング手段としては、高精度の測定が可能なＣＯＤ計を用いてＣＯＤ濃度を測定するのが好ましい。 Next, the correlation between measured values by the COD monitoring means will be described.
FIG. 2 shows the correlation between the measured value of the UV meter (absorbance at 254 nm) and the measured value of the COD meter in sulfur wastewater. It can be seen that a linear proportional correlation is obtained although the proportionality constant is slightly different depending on the wastewater.
3 shows the correlation between the measured value of the UV meter (absorbance at 254 nm) and the thiosulfate ion concentration, and FIG. 4 shows the correlation between the measured value of the UV meter (absorbance at 254 nm) and the sulfide ion concentration. From these figures, it can be seen that both have a linear proportional relationship. However, when the composition of sulfide ions and thiosulfate ions changes, the measured value of the UV meter and the measured value of the COD meter deviate from the linear proportional relationship, and if chlorine is present, chlorine is detected by the UV meter, resulting in an error. Considering the characteristics, it is preferable to measure the COD concentration using a COD meter capable of measuring with high accuracy as the second monitoring means for measuring the primary treated water which is the inflow water to the post-treatment tank.

しかし、ＣＯＤ計は１回の測定に約１時間を要するため、急激な水質変動に対してタイムラグをできるだけ小さくしてより正確に酸化剤添加量を決定するには、ＣＯＤ計を２台以上用いて交互に分析を行い、分析時間間隔を狭くするのが好ましい。   However, since the COD meter takes about one hour for one measurement, two or more COD meters are used to determine the amount of oxidizer added more accurately by making the time lag as small as possible against sudden water quality fluctuations. It is preferable to perform the analysis alternately to narrow the analysis time interval.

また、図５にＣＯＤ計による測定値とＯＲＰ計の測定値の相関関係を示す。なお、図５中の浸出水Ａはチオ硫酸ナトリウムを水に添加したもの、浸出水Ｂは硫化ナトリウムを水に添加したもの、そして、浸出水Ｃはイオウ系廃水である。この結果より、ＣＯＤ濃度が０ｍｇ／Ｌに近い値となると、ＯＲＰ計の測定値は急激に増加し、＋４００ｍＶ以上の値をとることが分かる。更に、図６に酸化剤として次亜塩素酸ナトリウム用いた場合のＣＯＤ計による測定値と残留塩素濃度値の相関を示す。ＣＯＤが残存している場合には、塩素が消費され、ＣＯＤ成分がなくなってくると次亜塩素酸ナトリウムが酸化還元反応に利用されずに、残留塩素として浸出水中に残るようになるため残留塩素が検出される。以上、図５および図６の結果から、ＯＲＰが＋４００ｍＶ以上もしくは残留塩素が検出された場合に、ＣＯＤは排水基準である２０ｍｇ／Ｌ以下を満たしていると予測できる。   FIG. 5 shows the correlation between the measured value by the COD meter and the measured value by the ORP meter. In addition, the leachate A in FIG. 5 is obtained by adding sodium thiosulfate to water, the leachate B is obtained by adding sodium sulfide to water, and the leachate C is sulfur waste water. From this result, it is understood that when the COD concentration is close to 0 mg / L, the measured value of the ORP meter increases rapidly and takes a value of +400 mV or more. Further, FIG. 6 shows the correlation between the measured value by the COD meter and the residual chlorine concentration value when sodium hypochlorite is used as the oxidizing agent. When COD remains, when chlorine is consumed and the COD component disappears, sodium hypochlorite is not used for the oxidation-reduction reaction and remains in the leachate as residual chlorine. Is detected. As described above, from the results of FIGS. 5 and 6, when the ORP is +400 mV or more or the residual chlorine is detected, it can be predicted that the COD satisfies the drainage standard of 20 mg / L or less.

（実施例１）
処理フローの検討
図７、図８および図９に、イオウ系廃水のモデルとして、廃水発生量１０Ｌ／ｈおよび表１に示すＣＯＤ濃度変動パターンをかけた例について検討する処理フローを示す。図７は本発明に従う処理フロー（実施例）、図８は１段のフィードフォワード制御のみを実施した処理フロー（比較例１）、図９は１段のフィードバック制御のみを実施した処理フロー（比較例２）である。なお、酸化剤として、濃度が１０質量％の次亜塩素酸ナトリウム水溶液を用いた。 Example 1
Examination of Treatment Flow FIGS. 7, 8 and 9 show the treatment flow for examining an example of applying the wastewater generation amount of 10 L / h and the COD concentration fluctuation pattern shown in Table 1 as a model of sulfur wastewater. 7 is a processing flow according to the present invention (Example), FIG. 8 is a processing flow (Comparative Example 1) in which only one-stage feedforward control is performed, and FIG. 9 is a processing flow (Comparison) in which only one-stage feedback control is performed. Example 2). In addition, the sodium hypochlorite aqueous solution whose density | concentration is 10 mass% was used as an oxidizing agent.

Figure 0005077065
Figure 0005077065

図７に示す実施例においては、第１処理槽２１および第２処理槽２７は内容積が２０Ｌのものを用いる。また、第１モニタリング手段としてはＵＶ計２２を用い、第１処理槽２１では予測されたＣＯＤ濃度値に対して１００％酸化されるよう酸化剤を添加するものとする。第２モニタリング手段としては測定間隔１回／１時間の１台のＣＯＤ計２８を用い、このＣＯＤ計２８の誤差は約０％である。第２処理槽２７では、ＣＯＤ計２８の最新の出力値に対して、２次処理水３１のＣＯＤ濃度値が１０ｍｇ／Ｌとなるように酸化剤を添加するものとする。また、前述したとおり、ＣＯＤ計２８は測定に約１時間要するため、実験開始後１時間は出力値が得られない。この間の第２処理槽２７での第２酸化剤は、ＵＶ計２２の出力値と第１処理槽２１での酸化剤添加量から計算される１次処理水２６のＣＯＤ濃度値に対して、２次処理水３１のＣＯＤ濃度値が１０ｍｇ／Ｌとなるように添加される。フィードバック制御用の第３モニタリング手段としてはＯＲＰ計３２を用い、設定値はＯＲＰ計３２の測定値から換算されるＣＯＤ濃度値が１０±５ｍｇ／Ｌとし、設定値の範囲から外れた場合には、ＣＯＤ濃度値が１０分あたり２ｍｇ／Ｌ変化するように第３酸化剤の添加量を設定する。   In the embodiment shown in FIG. 7, the first treatment tank 21 and the second treatment tank 27 have an internal volume of 20L. Further, a UV meter 22 is used as the first monitoring means, and an oxidizing agent is added in the first treatment tank 21 so as to be 100% oxidized with respect to the predicted COD concentration value. As the second monitoring means, one COD meter 28 with a measurement interval of once / hour is used, and the error of this COD meter 28 is about 0%. In the second treatment tank 27, an oxidizing agent is added so that the COD concentration value of the secondary treated water 31 becomes 10 mg / L with respect to the latest output value of the COD meter 28. As described above, since the COD meter 28 takes about 1 hour to measure, an output value cannot be obtained for 1 hour after the start of the experiment. During this time, the second oxidant in the second treatment tank 27 has a COD concentration value of the primary treatment water 26 calculated from the output value of the UV meter 22 and the oxidant addition amount in the first treatment tank 21. It is added so that the COD concentration value of the secondary treated water 31 is 10 mg / L. When the ORP meter 32 is used as the third monitoring means for feedback control and the set value is 10 ± 5 mg / L, the COD concentration value converted from the measured value of the ORP meter 32 is out of the set value range. The amount of the third oxidizing agent added is set so that the COD concentration value changes by 2 mg / L per 10 minutes.

図８に示す比較例１においては、イオウ系廃水１０１のＣＯＤ濃度値の測定をＣＯＤ計１０３により行い、処理水１０７のＣＯＤ濃度値が１０ｍｇ／Ｌとなるように酸化剤を添加する。この比較例１においても、ＣＯＤ計１０３の分析頻度は１回／１時間であり、実験開始後１時間は測定結果がでないため、発生した廃水のＣＯＤ初期値が既知のものであると仮定する。   In Comparative Example 1 shown in FIG. 8, the COD concentration value of the sulfur waste water 101 is measured by the COD meter 103, and an oxidizing agent is added so that the COD concentration value of the treated water 107 becomes 10 mg / L. Also in this comparative example 1, since the analysis frequency of the COD meter 103 is 1 time / 1 hour and there is no measurement result for 1 hour after the start of the experiment, it is assumed that the initial COD value of the generated wastewater is known. .

図９に示す比較例２においては、イオウ系廃水２０１のＣＯＤ濃度値の測定は行わず、処理水２０７のＣＯＤ濃度値が１０±５ｍｇ／Ｌとなるように、ＯＲＰ計２０６で酸化剤添加量を調整する。実施例に、ＯＲＰ計２０６による測定値から換算されるＣＯＤ濃度値が、設定範囲から外れた場合には、ＣＯＤ濃度値が１０分あたり、２ｍｇ／Ｌ変化するように添加量を設定する。   In Comparative Example 2 shown in FIG. 9, the COD concentration value of the sulfur-based wastewater 201 is not measured, and the oxidizer addition amount by the ORP meter 206 so that the COD concentration value of the treated water 207 becomes 10 ± 5 mg / L. Adjust. In the example, when the COD concentration value converted from the measured value by the ORP meter 206 is out of the set range, the addition amount is set so that the COD concentration value changes by 2 mg / L per 10 minutes.

図１０は、表１に示す廃水のＣＯＤ濃度変動パターン１における各例の処理水のＣＯＤ濃度を示し、同様に、図１１は表１に示す廃水のＣＯＤ濃度変動パターン２における各例の処理水のＣＯＤ濃度を示す。尚、図１０では、酸化剤を過剰に入れた場合には、酸化剤添加量から計算される酸化可能なＣＯＤ濃度を負の値として示す。図１０の結果から、ＣＯＤ濃度が急激に低い廃水が流入した場合であっても、本発明の実施例では、１段のフィードフォワード制御もしくはフィードバック制御の一方を行った場合である比較例１および２に比べて、ＣＯＤ濃度の負値が小さく、酸化剤の入れすぎを回避できることがわかる。また、図１１の結果から、ＣＯＤ濃度が急激に高い廃水が流入した場合であっても、１段のフィードフォワード制御もしくはフィードバック制御の一方を行った場合である比較例１および２に比べて、本発明では、ＣＯＤ濃度が目標値を大幅に上回る可能性も小さく抑えられている。   FIG. 10 shows the COD concentration of the treated water in each example in the COD concentration fluctuation pattern 1 of the wastewater shown in Table 1. Similarly, FIG. 11 shows the treated water of each example in the COD concentration fluctuation pattern 2 of the wastewater shown in Table 1. COD concentration is shown. In FIG. 10, when an oxidizing agent is excessively added, the oxidizable COD concentration calculated from the oxidizing agent addition amount is shown as a negative value. From the results of FIG. 10, even when waste water with a low COD concentration flows in, in the example of the present invention, the comparative example 1 and the case where either one-stage feedforward control or feedback control is performed and Compared to 2, the negative value of the COD concentration is small, and it can be seen that excessive addition of the oxidizing agent can be avoided. Further, from the results of FIG. 11, even when wastewater having a high COD concentration flows in, compared to Comparative Examples 1 and 2 in which one of the one-stage feedforward control or feedback control is performed, In the present invention, the possibility that the COD concentration greatly exceeds the target value is also kept small.

（実施例２）
処理槽での酸化剤添加量の検討
第１処理槽での第１酸化剤の添加方式について記載する。表２に第１酸化剤の添加方式を示す。実施例Ａとしては、廃水のＣＯＤ濃度に対して、１００％が酸化処理できるように添加した。実施例Ｂとしては、第１処理槽から流出する２次処理水のＣＯＤ濃度値が３０ｍｇ／Ｌとなるように酸化剤を注入するものとした。ここで、モデル廃水は、廃水発生量を１０Ｌ／ｈとし、ＣＯＤ濃度変動パターンは表３に示したとおりである。その他の運転項目(ＵＶ計の誤差、ＣＯＤ計の時間間隔、第２処理槽における酸化剤添加量の初期値の決定方法、処理水ＣＯＤ目標値、ＯＲＰ計設定値など)は実施例１と同様である。 (Example 2)
Examination of Addition Amount of Oxidant in Treatment Tank The method of adding the first oxidant in the first treatment tank is described. Table 2 shows the method of adding the first oxidizing agent. As Example A, it was added so that 100% of the COD concentration of wastewater could be oxidized. As Example B, the oxidizing agent was injected so that the COD concentration value of the secondary treated water flowing out from the first treatment tank was 30 mg / L. Here, the model wastewater has a wastewater generation amount of 10 L / h, and the COD concentration fluctuation pattern is as shown in Table 3. Other operation items (UV meter error, time interval of COD meter, determination method of initial value of oxidizer addition amount in second treatment tank, treated water COD target value, ORP meter set value, etc.) are the same as in Example 1. It is.

Figure 0005077065
Figure 0005077065

Figure 0005077065
Figure 0005077065

図１２に廃水のＣＯＤ濃度変動パターン３における各酸化剤添加方式での処理水のＣＯＤ濃度値を示し、同様に、図１３に廃水のＣＯＤ濃度変動パターン４における各酸化剤添加方式での処理水のＣＯＤ濃度値を示す。図１２より、実施例Ａでは、流入するＣＯＤ濃度が急激に低下した場合に、酸化剤を入れすぎてしまうことがわかる。また、図１３より、流入ＣＯＤ濃度が急激に増加した場合に、実施例Ａでは処理水ＣＯＤ濃度が高くなることがわかる。これらの原因としては、第２モニタリング手段にＣＯＤ計を用いていることが挙げられる。ＣＯＤ計は、測定精度は高いものの１時間に約１回の分析頻度でしか測定できないため、流入ＣＯＤに対して定率で酸化剤を投入した場合には、流入ＣＯＤの変動にあわせて第１処理槽中の処理水ＣＯＤ濃度が変動するために、ＣＯＤ計の測定間隔である１時間でのＣＯＤ濃度変化が影響することが挙げられる。一方で、実施例Ｂでは、廃水のＣＯＤ第１モニタリング手段であるＵＶ計の誤差が影響するだけとなるため、処理水濃度が一定となるように酸化剤を注入した場合の方が、処理水のＣＯＤ濃度値が安定して、目標値により近い値を得やすいことがわかる。   FIG. 12 shows the COD concentration value of the treated water in each oxidizer addition method in the COD concentration fluctuation pattern 3 of the wastewater. Similarly, FIG. 13 shows the treated water in each oxidizer addition method in the COD concentration fluctuation pattern 4 of the wastewater. The COD concentration value is shown. From FIG. 12, it can be seen that in Example A, when the inflowing COD concentration is drastically reduced, the oxidant is excessively added. In addition, FIG. 13 shows that the treated water COD concentration becomes higher in Example A when the inflow COD concentration increases rapidly. As these causes, a COD meter is used as the second monitoring means. Although the COD meter has high measurement accuracy, it can only measure with an analysis frequency of about once per hour. Therefore, when an oxidant is introduced at a constant rate with respect to the inflow COD, the first processing is performed in accordance with the fluctuation of the inflow COD. Since the treated water COD concentration in the tank fluctuates, a change in the COD concentration in one hour, which is the measurement interval of the COD meter, is affected. On the other hand, in Example B, since the error of the UV meter which is the COD first monitoring means of the wastewater is only affected, the treatment water is injected when the oxidizing agent is injected so that the treatment water concentration becomes constant. It can be seen that the COD concentration value is stable and a value closer to the target value can be easily obtained.

ただし、廃水のＣＯＤ測定予測値に対して、第１処理槽でのＣＯＤ除去率が設定値（目標除去率）となるように次亜塩素酸ナトリウム溶液を添加する方式についても、各処理槽流入水のＣＯＤ計台数を増やすことで、測定間隔が短くなり、目標値を満足できるようになる。さらに、廃水のＣＯＤ濃度が高い場合には、ＣＯＤ濃度予測値に誤差を生じやすくなるため、例えば、ＣＯＤ１０００ｍｇ／Ｌの廃水の処理において、方式１）第１処理槽の処理水ＣＯＤ濃度値を５０ｍｇ／Ｌ（一定）とする方式と方式２）第１処理槽で１００％のＣＯＤを処理する方式とを比較する。このときに、測定値に１０％誤差があり、実際の廃水ＣＯＤ濃度が９００ｍｇ／Ｌであった場合、実際の処理水ＣＯＤ濃度は方式１）では−５０ｍｇ／Ｌ、方式２）では−１００ｍｇ／Ｌとなる。つまり、ＣＯＤ測定値に対してＣＯＤ除去率を一定とした場合が有効となることがある。   However, the sodium hypochlorite solution is added to the treatment tank so that the COD removal rate in the first treatment tank becomes a set value (target removal rate) with respect to the COD measurement predicted value of the wastewater. By increasing the number of water COD meters, the measurement interval is shortened and the target value can be satisfied. Furthermore, when the COD concentration of wastewater is high, an error is likely to occur in the predicted COD concentration. For example, in the treatment of wastewater with a COD of 1000 mg / L, the method 1) the treated water COD concentration value of the first treatment tank is 50 mg. / L (constant) method and method 2) A method of treating 100% COD in the first treatment tank is compared. At this time, if the measured value has a 10% error and the actual wastewater COD concentration is 900 mg / L, the actual treated water COD concentration is -50 mg / L in Method 1) and -100 mg / L in Method 2). L. That is, the case where the COD removal rate is constant with respect to the COD measurement value may be effective.

図１は、ＣＯＤ成分を含有する廃水の連続処理装置の工程図である。FIG. 1 is a process diagram of a continuous treatment apparatus for wastewater containing a COD component. 図２は、ＣＯＤ成分を含有する廃水におけるＵＶ計の測定値とＣＯＤ計による測定値の相関を示すグラフである。FIG. 2 is a graph showing the correlation between the measured value of the UV meter and the measured value of the COD meter in wastewater containing a COD component. 図３は、ＵＶ計の測定値とチオ硫酸イオン濃度の相関を示すグラフである。FIG. 3 is a graph showing the correlation between the measured value of the UV meter and the thiosulfate ion concentration. 図４は、ＵＶ計の測定値と硫化物イオン濃度の相関を示すグラフである。FIG. 4 is a graph showing the correlation between the measured value of the UV meter and the sulfide ion concentration. 図５は、ＣＯＤ濃度とＯＲＰ計の測定値の相関を示すグラフである。FIG. 5 is a graph showing the correlation between the COD concentration and the measured value of the ORP meter. 図６は、ＣＯＤ濃度と残留塩素濃度値の相関を示すグラフである。FIG. 6 is a graph showing the correlation between the COD concentration and the residual chlorine concentration value. 図７は、実施例を示す工程図である。FIG. 7 is a process diagram showing an example. 図８は、１段のフィードフォワード制御のみを実施した比較例１を示す工程図である。FIG. 8 is a process diagram showing Comparative Example 1 in which only one-stage feedforward control is performed. 図９は、１段のフィードバック制御のみを実施した比較例２を示す工程図である。FIG. 9 is a process diagram showing a comparative example 2 in which only one-stage feedback control is performed. 図１０は、廃水のＣＯＤ濃度変動パターン１における実施例ならびに比較例１および２で処理したときのＣＯＤ濃度変化を示すグラフである。FIG. 10 is a graph showing the COD concentration change when the waste water is treated in the COD concentration fluctuation pattern 1 of the example and the comparative examples 1 and 2. 図１１は、廃水のＣＯＤ濃度変動パターン２における実施例ならびに比較例１および２で処理したときのＣＯＤ濃度変化を示すグラフである。FIG. 11 is a graph showing the COD concentration change when the wastewater is treated in the COD concentration fluctuation pattern 2 of the example and the comparative examples 1 and 2. 図１２は、廃水のＣＯＤ濃度変動パターン３における実施例ＡおよびＢで処理したときのＣＯＤ濃度変化を示すグラフである。FIG. 12 is a graph showing changes in COD concentration when treated in Examples A and B in the COD concentration fluctuation pattern 3 of wastewater. 図１３は、廃水のＣＯＤ濃度変動パターン４における実施例ＡおよびＢで処理したときのＣＯＤ濃度変化を示すグラフである。FIG. 13 is a graph showing changes in COD concentration when treated in Examples A and B in the COD concentration fluctuation pattern 4 of wastewater.

符号の説明Explanation of symbols

１ 廃水
２ 第１流入口
３ 第１処理槽
４ 第１流出口
５ 第１モニタリング手段
６ 第１制御手段
７ 第１酸化剤注入手段
８ 酸化剤貯留手段
９ １次処理水
１０ 第２流入口
１１ 第２処理槽
１２ 第２流出口
１３ 第２モニタリング手段
１４ 第２制御手段
１５ 第２酸化剤注入手段
１６ ２次処理水
１７ 第３モニタリング手段
１８ 第３制御手段
２０ 廃水
２１ 第１処理槽
２２ ＵＶ計
２３ 第１制御手段
２４ 第１酸化剤注入手段
２５ 酸化剤貯留手段
２６ １次処理水
２７ 第２処理槽
２８ ＣＯＤ計
２９ 第２制御手段
３０ 第２酸化剤注入手段
３１ ２次処理水
３２ ＯＲＰ計
３３ 第３制御手段
１０１ イオウ系廃水
１０２ 第１処理槽
１０３ ＣＯＤ計
１０４ 制御手段
１０５ 注入手段
１０６ 酸化剤貯留手段
１０７ 処理水
２０１ イオウ系廃水
２０２ 第１処理槽
２０３ 注入手段
２０４ 酸化剤貯留手段
２０５ 制御手段
２０６ ＯＲＰ計
２０７ 処理水 DESCRIPTION OF SYMBOLS 1 Waste water 2 1st inflow port 3 1st processing tank 4 1st outflow port 5 1st monitoring means 6 1st control means 7 1st oxidizing agent injection | pouring means 8 Oxidant storage means 9 Primary treated water 10 2nd inflow port 11 Second treatment tank 12 Second outlet 13 Second monitoring means 14 Second control means 15 Second oxidant injection means 16 Secondary treated water 17 Third monitoring means 18 Third control means 20 Waste water 21 First treatment tank 22 UV Total 23 First control means 24 First oxidant injection means 25 Oxidant storage means 26 Primary treated water 27 Second treatment tank 28 COD meter 29 Second control means 30 Second oxidant injection means 31 Secondary treated water 32 ORP Total 33 Third control means 101 Sulfur waste water 102 First treatment tank 103 COD meter 104 Control means 105 Injection means 106 Oxidant storage means 107 Treated water 201 Sulfur system Waste water 202 First treatment tank 203 Injection means 204 Oxidant storage means 205 Control means 206 ORP meter 207 Treated water

Claims (3)

ＣＯＤ成分を含有する廃水を流入させる第１流入口と前記廃水の処理水である１次処理水を流出させる第１流出口とを有する第１処理槽、前記第１流入口の上流側に設けられた、廃水のＣＯＤ濃度と相関関係を有する第１の物性値を測定するＵＶ計からなる第１モニタリング手段、前記第１処理槽へ第１酸化剤を添加する第１酸化剤注入手段、および、前記第１物性値から前記第１モニタリング手段で予測した第１ＣＯＤ濃度予測値に基づいて前記第１処理槽へ添加する第１酸化剤の添加量を決定し、かつ前記第１酸化剤注入手段による前記第１処理槽への第１酸化剤の添加量を制御する第１制御手段を有する１つの前処理系装置、ならびに
前記第１処理槽の第１流出口から流出する１次処理水を流入させる第２流入口と前記１次処理水の処理水である２次処理水を流出させる第２流出口とを有する第２処理槽、前記第２流入口の上流側に設けられた、１次処理水のＣＯＤ濃度を測定する１台または複数台 のＣＯＤ計からなる第２モニタリング手段、前記第２処理槽へ第２酸化剤を添加する第２酸化剤注入手段、および、前記第２モニタリング手段で測定した第２ＣＯＤ濃度測定値に基づいて前記第２処理槽へ添加する第２酸化剤の添加量を決定し、かつ前記第２酸化剤注入手段による前記第２処理槽への第２酸化剤の添加量を制御する第２制御手段を有する少なくとも１つの後処理系装置を有することを特徴とするＣＯＤ成分を含有する廃水の連続処理装置。A first treatment tank having a first inlet through which waste water containing a COD component flows in and a first outlet through which primary treated water, which is the treated water of the waste water, flows out, is provided upstream of the first inlet. A first monitoring means comprising a UV meter for measuring a first physical property value correlated with the COD concentration of the wastewater, a first oxidant injection means for adding a first oxidant to the first treatment tank, and Determining the addition amount of the first oxidant to be added to the first treatment tank based on the first COD concentration predicted value predicted by the first monitoring means from the first physical property value; and the first oxidant injection means. One pretreatment system device having a first control means for controlling the amount of the first oxidant added to the first treatment tank by the first treatment water, and primary treatment water flowing out from the first outlet of the first treatment tank The second inlet to be introduced and the treatment of the primary treated water A second treatment tank having a second outlet for discharging secondary treated water, which is water, and one or a plurality of units for measuring the COD concentration of the primary treated water provided on the upstream side of the second inlet. Based on the second COD concentration measurement value measured by the second monitoring means comprising a COD meter of the stage, the second oxidant injection means for adding the second oxidant to the second treatment tank, and the second monitoring means A second control unit configured to determine an addition amount of the second oxidant to be added to the second treatment tank and to control an addition amount of the second oxidant to the second treatment tank by the second oxidant injection unit; A continuous treatment apparatus for wastewater containing a COD component, comprising at least one aftertreatment system apparatus. ＣＯＤ成分を含有する廃水のＣＯＤ濃度と一次比例の相関関係を有する第１の物性値をＵＶ計で測定し、この測定値から予測した第１ＣＯＤ濃度予測値に基づいて目標ＣＯＤ濃度にするために必要な第１酸化剤の添加量を決定し、決定された量の第１酸化剤を前記廃水に添加して１次処理水とする、フィードフォワード制御による１つの前処理工程と、
前記１次処理水のＣＯＤ濃度をＣＯＤ計で測定し、この測定した第２ＣＯＤ濃度測定値に基づいて目標ＣＯＤ濃度にするために必要な第２酸化剤の添加量を決定し、決定された量の第２酸化剤を前記１次処理水に添加して２次処理水とする、フィードフォワード制御による少なくとも１つの後処理工程と
を有することを特徴とするＣＯＤ成分を含有する廃水の処理方法。To measure the first physical property value having a linear proportional correlation with the COD concentration of the wastewater containing the COD component with a UV meter, and to obtain the target COD concentration based on the predicted first COD concentration value predicted from this measured value One pretreatment step by feedforward control for determining a necessary amount of the first oxidant to be added, and adding the determined amount of the first oxidant to the waste water as primary treated water;
The COD concentration of the primary treated water is measured with a COD meter, and the addition amount of the second oxidant necessary for achieving the target COD concentration is determined based on the measured second COD concentration measurement value, and the determined amount A method for treating wastewater containing a COD component, comprising: adding at least one post-treatment step by feedforward control to add secondary oxidant to secondary treated water. 前記第２ＣＯＤ濃度測定値が、２台以上のＣＯＤ計で所定時間ずらして測定した値であることを特徴とする請求項２に記載のＣＯＤ成分を含有する廃水の連続処理方法。3. The continuous treatment method for wastewater containing a COD component according to claim 2 , wherein the second COD concentration measurement value is a value measured with two or more COD meters shifted by a predetermined time.
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