JP2023090374A

JP2023090374A - Water treatment apparatus

Info

Publication number: JP2023090374A
Application number: JP2021205305A
Authority: JP
Inventors: 修金井; Osamu Kanai; 伸一大橋; Shinichi Ohashi; 徹中野; Toru Nakano; 勇規中村; Yuki Nakamura; 淳中円尾; Atsushi Nakamaruo
Original assignee: Organo Corp; Japan Organo Co Ltd
Current assignee: Organo Corp
Priority date: 2021-12-17
Filing date: 2021-12-17
Publication date: 2023-06-29

Abstract

To provide a water treatment apparatus capable of removing a predetermined substance and increasing the volume of treated water that can be discharged.SOLUTION: A water treatment apparatus 1 includes: a raw water tank 2 for storing raw water containing a predetermined substance; at least one reverse osmosis membrane device 6 for separating raw water pumped from the raw water tank 2 into permeated water and concentrated water; a concentrated water circulation line L5 for returning concentrated water to the raw water tank 2; a treated water tank 7 for storing the permeated water as the treated water; and concentration acquiring means 10 for acquiring the concentration of a predetermined substance in the treated water stored in the treated water tank 7. When the concentration acquired by the concentration acquisition means 10 reaches a predetermined value, at least a part of the treated water stored in the treated water tank 7 is discharged from the treated water tank 7.SELECTED DRAWING: Figure 1

Description

本発明は水処理装置に関し、特にホウ素含有水からホウ素を除去する水処理装置に関する。 The present invention relates to water treatment equipment, and more particularly to water treatment equipment for removing boron from boron-containing water.

産業排水や発電所の排水に含まれるホウ素を逆浸透膜装置で除去する水処理装置が知られている。ホウ素は、飲料水基準（ＷＨＯ、国内）が設けられ（１ｍｇ／Ｌ）、排水規制でも排出基準が設けられている（国内では海域２３０ｍｇ／Ｌ、陸域１０ｍｇ／Ｌ）。ホウ素は海水中にも含まれている（４～５ｍｇ／Ｌ程度）。ホウ素はホウ酸とホウ酸イオンの平衡状態で水中に存在し、特にホウ酸の状態で存在しているホウ素（イオン化していないホウ素）は、逆浸透膜を透過しやすい特質がある。従って、ホウ素は排水中に多く含まれることがある物質であるが、除去しにくい物質でもある。そこで、ホウ素の除去率を高めるために、逆浸透膜装置の濃縮水を逆浸透膜装置に戻す再循環方式が採用されることがある（特許文献１，２）。濃縮水を逆浸透膜装置に戻すことで、濃縮水中のホウ素濃度が高められ、濃縮水の減容処理も容易となる。 A water treatment apparatus is known that removes boron contained in industrial wastewater and power plant wastewater using a reverse osmosis membrane device. For boron, drinking water standards (WHO, Japan) are established (1 mg/L), and discharge standards are also established in wastewater regulations (in Japan, 230 mg/L for sea areas and 10 mg/L for land areas). Boron is also contained in seawater (approximately 4 to 5 mg/L). Boron exists in water in an equilibrium state of boric acid and borate ions, and in particular, boron that exists in the state of boric acid (boron that is not ionized) has the property of easily permeating a reverse osmosis membrane. Therefore, boron is a substance that is often contained in waste water, but it is also a substance that is difficult to remove. Therefore, in order to increase the boron removal rate, a recirculation system is sometimes adopted in which the concentrated water of the reverse osmosis membrane device is returned to the reverse osmosis membrane device (Patent Documents 1 and 2). By returning the concentrated water to the reverse osmosis membrane device, the boron concentration in the concentrated water is increased, and the volume reduction treatment of the concentrated water is facilitated.

特開２０１５－１４４９９７号公報JP 2015-144997 A 特開２００８－２３７９８６号公報JP-A-2008-237986

特許文献１，２に開示された水処理装置においては、逆浸透膜装置の入口水のホウ素濃度が時間ともに増加する。しかし、逆浸透膜装置のホウ素阻止率、すなわち、逆浸透膜装置の１次側（濃縮側）と２次側（透過側）におけるホウ素濃度の比率は、原水中のホウ素濃度によらずほぼ一定であるため、逆浸透膜の２次側のホウ素濃度も時間とともに増加する。上述の通り、処理水中のホウ素濃度が所定の放水基準値に達すると放水ができなくため、１次側の原水を抜き、ホウ素濃度の低い原水に入れ替えるといった作業が必要となる。従って、従来の技術では、放水可能な処理水の水量を増やすことは困難である。ホウ素以外の物質についても同様の課題が存在する。 In the water treatment apparatuses disclosed in Patent Documents 1 and 2, the concentration of boron in the inlet water of the reverse osmosis membrane apparatus increases with time. However, the boron rejection rate of the reverse osmosis membrane device, that is, the ratio of the boron concentration on the primary side (concentration side) and the secondary side (permeation side) of the reverse osmosis membrane device, is almost constant regardless of the boron concentration in the raw water. Therefore, the boron concentration on the secondary side of the reverse osmosis membrane also increases with time. As described above, when the boron concentration in the treated water reaches a predetermined water discharge standard value, water cannot be discharged. Therefore, it is difficult to increase the amount of treated water that can be discharged with the conventional technology. Similar problems exist for substances other than boron.

本発明は、所定の物質の除去が可能で、放水可能な処理水の水量を増やすことのできる水処理装置を提供することを目的とする。 SUMMARY OF THE INVENTION An object of the present invention is to provide a water treatment apparatus capable of removing a predetermined substance and increasing the amount of treated water that can be discharged.

本発明の水処理装置は、所定の物質を含む原水を貯留する原水タンクと、原水タンクから送水された原水を透過水と濃縮水とに分離する少なくとも一つの逆浸透膜装置と、濃縮水を原水タンクに戻す濃縮水循環ラインと、透過水を処理水として貯留する処理水タンクと、処理水タンクに貯留された処理水中の所定の物質の濃度を取得する濃度取得手段と、を有している。そして、濃度取得手段で取得された濃度が所定の値に達したときに、処理水タンクに貯留された処理水の少なくとも一部が処理水タンクから排出される。 The water treatment apparatus of the present invention comprises a raw water tank for storing raw water containing a predetermined substance, at least one reverse osmosis membrane device for separating raw water fed from the raw water tank into permeated water and concentrated water, and concentrated water. It has a concentrated water circulation line that returns to the raw water tank, a treated water tank that stores permeated water as treated water, and a concentration acquisition means that acquires the concentration of a predetermined substance in the treated water stored in the treated water tank. . At least part of the treated water stored in the treated water tank is discharged from the treated water tank when the concentration obtained by the concentration obtaining means reaches a predetermined value.

本発明によれば、所定の物質の除去が可能で、放水可能な処理水の水量を増やすことのできる水処理装置を提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, the removal of a predetermined|prescribed substance is possible and the water treatment apparatus which can increase the water quantity of the treated water which can be discharged can be provided.

本発明の第１の実施形態に係る水処理装置の概略構成図である。BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the water treatment apparatus which concerns on the 1st Embodiment of this invention. 処理時間と濃度相関パラメータとの関係の一例を示す図である。FIG. 5 is a diagram showing an example of the relationship between processing time and concentration correlation parameter; 本発明の第２の実施形態に係る水処理装置の概略構成図である。It is a schematic block diagram of the water treatment apparatus which concerns on the 2nd Embodiment of this invention. 本発明の第３の実施形態に係る水処理装置の概略構成図である。It is a schematic block diagram of the water treatment apparatus which concerns on the 3rd Embodiment of this invention. 本発明の第３の実施形態の第１の変形例に係る水処理装置の概略構成図である。It is a schematic block diagram of the water treatment apparatus which concerns on the 1st modification of the 3rd Embodiment of this invention. 本発明の第３の実施形態の第２の変形例に係る水処理装置の概略構成図である。It is a schematic block diagram of the water treatment apparatus which concerns on the 2nd modification of the 3rd Embodiment of this invention. 本発明の第４の実施形態に係る水処理装置の概略構成図である。It is a schematic block diagram of the water treatment apparatus which concerns on the 4th Embodiment of this invention.

以下、図面を参照して本発明の水処理装置のいくつかの実施形態について説明する。以下の実施形態において、逆浸透膜装置は原水中のホウ素を除去するために設けられているが、原水は逆浸透膜装置が除去可能な所定の物質を含んでいればよい。本実施形態では所定の物質はホウ素であるが、所定の物質はホウ素に限定されない。対象とする原水のホウ素濃度は限定されないが、例えば数十～数千ｐｐｍオーダーである。 Hereinafter, some embodiments of the water treatment apparatus of the present invention will be described with reference to the drawings. In the following embodiments, the reverse osmosis membrane device is provided to remove boron in raw water, but the raw water may contain a predetermined substance that can be removed by the reverse osmosis membrane device. Although the predetermined substance is boron in this embodiment, the predetermined substance is not limited to boron. Although the boron concentration of the target raw water is not limited, it is, for example, on the order of several tens to several thousand ppm.

（第１の実施形態）
図１に、本発明の第１の実施形態に係る水処理装置１の概略構成を示す。水処理装置１は、ホウ素を含む原水を貯留する原水タンク２を有している。原水は、ホウ素を取り扱う工場、発電所、温泉施設、廃棄物の埋立場、鉱山などから排出されるホウ素含有排水である。原水タンク２には原水の供給ライン（以下、原水供給ラインＬ１という）が接続され、原水供給ラインＬ１には第１の弁Ｖ１が設けられている。水処理装置１は、原水タンク２から供給される原水を透過水と濃縮水とに分離する、少なくとも一つ（本実施形態では一つ）の逆浸透膜装置６を有している。逆浸透膜装置６は逆浸透膜６１によって、原水が濃縮される濃縮側空間６２と、透過水が透過する透過側空間６３とに分けられる。逆浸透膜６１は、膜に作用する圧力によって高圧用、中圧用、低圧用、超低圧用などに分類されるが、本実施形態ではどのタイプも利用可能である。しかし、ホウ素阻止率は高圧用の逆浸透膜の方が高いため、特に原水のホウ素濃度が高い場合は、高圧用の逆浸透膜を用いることがより好ましい。高圧用逆浸透膜とは、一般に、２５℃条件下において、膜面有効圧力１．０ＭＰａあたりの透過流束が０．３～０．６５ｍ^３／ｍ^２／ｄａｙであり、ＮａＣｌ除去率が９９．５％以上のものである。原水タンク２と逆浸透膜装置６との間には、原水の供給方向に沿って上流から下流に向けて、原水を圧送するポンプ３と、原水中の夾雑物や塵埃を除去するフィルタ４と、原水のｐＨを調整するｐＨ調整手段５とが、直列に設けられている。フィルタ４としては、メッシュストレーナ、限外濾過膜（ＵＦ膜）、精密ろ過膜（ＭＦ膜）、安全フィルタなどを使用することができる。ホウ素の除去効率はｐＨを高くすることで向上する。ｐＨは５～９が好ましいが、これに限定されない。フィルタ４とｐＨ調整手段５の設置は任意であり、いずれかまたは両方を省略することもできる。また、フィルタ４とｐＨ調整手段５は、原水タンク２の前段に設置しても構わない。 (First embodiment)
FIG. 1 shows a schematic configuration of a water treatment device 1 according to a first embodiment of the present invention. The water treatment device 1 has a raw water tank 2 that stores raw water containing boron. Raw water is boron-containing wastewater discharged from factories, power plants, hot spring facilities, waste landfills, mines, etc. that handle boron. A raw water supply line (hereinafter referred to as a raw water supply line L1) is connected to the raw water tank 2, and the raw water supply line L1 is provided with a first valve V1. The water treatment apparatus 1 has at least one (one in this embodiment) reverse osmosis membrane device 6 that separates raw water supplied from the raw water tank 2 into permeated water and concentrated water. The reverse osmosis membrane device 6 is divided by a reverse osmosis membrane 61 into a concentration side space 62 in which raw water is concentrated and a permeate side space 63 in which permeated water passes. The reverse osmosis membrane 61 is classified into high-pressure, medium-pressure, low-pressure, ultra-low-pressure, etc. according to the pressure acting on the membrane, and any type can be used in this embodiment. However, since the reverse osmosis membrane for high pressure has a higher boron rejection rate, it is more preferable to use the reverse osmosis membrane for high pressure especially when the raw water has a high boron concentration. A high-pressure reverse osmosis membrane generally has a permeation flux of 0.3 to 0.65 m ³ /m ² /day per 1.0 MPa of membrane surface effective pressure at 25 ° C., and a NaCl removal rate of 99. .5% or more. Between the raw water tank 2 and the reverse osmosis membrane device 6, a pump 3 for pumping the raw water and a filter 4 for removing contaminants and dust in the raw water are provided from upstream to downstream along the raw water supply direction. , and a pH adjusting means 5 for adjusting the pH of the raw water are provided in series. As the filter 4, a mesh strainer, an ultrafiltration membrane (UF membrane), a microfiltration membrane (MF membrane), a safety filter, or the like can be used. Boron removal efficiency improves with increasing pH. The pH is preferably 5 to 9, but is not limited to this. Installation of the filter 4 and the pH adjusting means 5 is optional, and either or both of them can be omitted. Moreover, the filter 4 and the pH adjusting means 5 may be installed before the raw water tank 2 .

水処理装置１は、透過水を貯留する処理水タンク７を有している。逆浸透膜装置６の透過側空間６３は透過水ラインＬ２によって、処理水タンク７に接続されている。透過水ラインＬ２には第２の弁Ｖ２が設けられている。後で詳しく説明するように、処理水タンク７は本実施形態における特徴的な設備であり、逆浸透膜装置６を透過した透過水はそのまま放水されずに、一旦処理水タンク７に貯留される。処理水タンク７は放水ラインＬ３に接続され、放水ラインＬ３には第３の弁Ｖ３が設けられている。原水タンク２には濃縮水排出ラインＬ４が接続され、濃縮水排出ラインＬ４には第４の弁Ｖ４が設けられている。逆浸透膜装置６の濃縮側空間６２と原水タンク２は、濃縮水を原水タンク２に戻す濃縮水循環ラインＬ５で接続されている。原水タンク２が小さい場合、ポンプ３の吐出圧が高い場合、透過水量を少なく設定した場合などは、濃縮水の循環により原水の温度が高くなる可能性がある。このため、濃縮水循環ラインＬ５には、濃縮水を冷却するための熱交換器Ｌ１３が設けられ、濃縮水の温度が高くなる場合は、温度を下げることができる。熱交換器Ｌ１３は、シェル＆チューブ型やプレート型などを使用することができる。熱交換器Ｌ１３は、省略することもできる。図１に示す弁Ｖ１～Ｖ４は、水処理装置１のバッチ運転中の状態を示している。なお、以下の説明において透過水は逆浸透膜装置６の透過側空間６３内の水であり、逆浸透膜装置６の出口水と同義である。処理水は処理水タンク７に貯蔵されている水を意味する。後述するように、透過水と処理水は異なる。 The water treatment apparatus 1 has a treated water tank 7 that stores permeated water. A permeate-side space 63 of the reverse osmosis membrane device 6 is connected to the treated water tank 7 by a permeated water line L2. A second valve V2 is provided in the permeate line L2. As will be described in detail later, the treated water tank 7 is a characteristic facility in this embodiment, and the permeated water that has passed through the reverse osmosis membrane device 6 is not discharged as it is, but is temporarily stored in the treated water tank 7. . The treated water tank 7 is connected to a water discharge line L3, and the water discharge line L3 is provided with a third valve V3. A concentrated water discharge line L4 is connected to the raw water tank 2, and the concentrated water discharge line L4 is provided with a fourth valve V4. The concentration side space 62 of the reverse osmosis membrane device 6 and the raw water tank 2 are connected by a concentrated water circulation line L5 that returns the concentrated water to the raw water tank 2 . When the raw water tank 2 is small, when the discharge pressure of the pump 3 is high, or when the amount of permeated water is set small, the temperature of the raw water may rise due to the circulation of the concentrated water. Therefore, the concentrated water circulation line L5 is provided with a heat exchanger L13 for cooling the concentrated water, and when the temperature of the concentrated water becomes high, the temperature can be lowered. A shell-and-tube type, a plate type, or the like can be used for the heat exchanger L13. The heat exchanger L13 can also be omitted. The valves V1 to V4 shown in FIG. 1 show the state during the batch operation of the water treatment apparatus 1. As shown in FIG. In the following description, the permeated water is the water in the permeate-side space 63 of the reverse osmosis membrane device 6 and is synonymous with the outlet water of the reverse osmosis membrane device 6 . Treated water means water stored in the treated water tank 7 . As described below, permeate and treated water are different.

水処理装置１は、処理水タンク７に貯留された処理水中のホウ素濃度を取得する濃度取得手段１０を有している。濃度取得手段１０は処理水タンク７に設けたホウ素濃度計であってもよいが、本実施形態では他の測定値から間接的に処理水中のホウ素濃度を算定する方法を採用している。後述するように、処理水中のホウ素濃度は所定の濃度相関パラメータと相関関係にある。濃度相関パラメータは、原水タンク２の水量、処理水タンク７の水量、逆浸透膜装置６での処理を開始してからの経過時間（以下、処理時間という）の、少なくともいずれかである。濃度相関パラメータは、濃度相関パラメータの測定手段８，９によって測定することができる。濃度相関パラメータの測定手段８，９は、原水タンク２の水量を得るために原水タンク２の水位を測定する第１の水位計８、処理水タンク７の水量を得るために処理水タンク７の水位を測定する第２の水位計９を有している。また、逆浸透膜装置６での処理時間を測定するためのタイマー（図示せず）を有していてもよい。図中には、濃度相関パラメータの測定手段８，９の例として、第１の水位計８と第２の水位計９を示している。濃度取得手段１０は、濃度相関パラメータの測定手段８，９の測定値を処理水タンク７の処理水中のホウ素濃度に換算する手段を有している。そして、濃度取得手段１０は、濃度相関パラメータの測定手段８，９で測定された濃度相関パラメータに基づき、処理水タンク７に貯留された処理水中の平均ホウ素濃度を算出し、算出した平均ホウ素濃度が所定の値に達したか否かを判定する。濃度取得手段１０は、例えば、水処理装置１の制御装置にプログラムとして組み込まれるが、運転員が濃度相関パラメータの測定値と換算表から処理水中の平均ホウ素濃度を求めることもできる。 The water treatment apparatus 1 has a concentration acquisition means 10 for acquiring the boron concentration in the treated water stored in the treated water tank 7 . The concentration acquisition means 10 may be a boron concentration meter provided in the treated water tank 7, but this embodiment adopts a method of indirectly calculating the boron concentration in the treated water from other measured values. As will be described later, the boron concentration in the treated water has a correlation with a predetermined concentration correlation parameter. The concentration correlation parameter is at least one of the amount of water in the raw water tank 2, the amount of water in the treated water tank 7, and the elapsed time from the start of treatment in the reverse osmosis membrane device 6 (hereinafter referred to as treatment time). The concentration correlation parameter can be measured by concentration correlation parameter measurement means 8 and 9 . Concentration correlation parameter measurement means 8 and 9 include a first water level gauge 8 for measuring the water level of the raw water tank 2 to obtain the amount of water in the raw water tank 2, It has a second water gauge 9 for measuring the water level. Also, a timer (not shown) for measuring the processing time in the reverse osmosis membrane device 6 may be provided. In the drawing, a first water level gauge 8 and a second water level gauge 9 are shown as examples of measuring means 8 and 9 for the concentration correlation parameter. The concentration acquisition means 10 has means for converting the measured values of the concentration correlation parameter measurement means 8 and 9 into the boron concentration in the treated water in the treated water tank 7 . Then, the concentration acquisition means 10 calculates the average boron concentration in the treated water stored in the treated water tank 7 based on the concentration correlation parameters measured by the concentration correlation parameter measuring means 8 and 9, and the calculated average boron concentration has reached a predetermined value. The concentration acquisition means 10 is incorporated as a program in the control device of the water treatment apparatus 1, for example, but the operator can obtain the average boron concentration in the treated water from the measured values of the concentration correlation parameters and the conversion table.

（水処理装置１の運転方法）
次に、水処理装置１の運転方法について説明する。まず、第１の弁Ｖ１、第２の弁Ｖ２を開き、第３の弁Ｖ３、第４の弁Ｖ４を閉じる。原水供給ラインＬ１から原水を原水タンク２に供給し、所定量の原水が原水タンク２に貯留されると第１の弁Ｖ１を閉じる。原水は、ホウ素含有水を多量に貯留している原水槽、排水槽などの塔槽類や、その他の水処理施設等（図示せず）から送水される。本実施形態において、水処理装置１はバッチ運転（回分式処理）で運転される。このため、バッチ運転中は第１の弁Ｖ１、第３の弁Ｖ３、第４の弁Ｖ４は閉じられており、水処理装置１の外部との水の出入りはない。 (Operating method of water treatment device 1)
Next, a method of operating the water treatment device 1 will be described. First, the first valve V1 and the second valve V2 are opened, and the third valve V3 and the fourth valve V4 are closed. Raw water is supplied from the raw water supply line L1 to the raw water tank 2, and when a predetermined amount of raw water is stored in the raw water tank 2, the first valve V1 is closed. The raw water is fed from towers and tanks such as a raw water tank, a waste water tank, and other water treatment facilities (not shown) that store a large amount of boron-containing water. In this embodiment, the water treatment apparatus 1 is operated by batch operation (batch type treatment). Therefore, the first valve V1, the third valve V3, and the fourth valve V4 are closed during the batch operation, and water does not flow into or out of the water treatment apparatus 1 .

次に、ポンプ３を起動し、逆浸透膜装置６に原水を送水し、原水を逆浸透膜装置６で処理する。送水流量と循環水流量（濃縮水循環ラインＬ５の流量）は、逆浸透膜装置６の膜種ごとに定められた最低必要流量が確保されるように選定する。透過水流量（透過水ラインＬ２の流量）は、膜の通水条件を逸脱しないように第２の弁Ｖ２の開度で調整する。第２の弁Ｖ２は定流量弁または調整弁でもよい。あるいは、ポンプ３の回転数で透過水流量を制御してもよい。原水に含まれるホウ素のうち、逆浸透膜６１のホウ素阻止率に相当する量が除去され、残りが透過側空間６３に透過する。ホウ素阻止率は、逆浸透膜装置６の入口水のホウ素濃度をＡ、逆浸透膜装置６の出口水のホウ素濃度をＢとしたときに、（Ａ－Ｂ）／Ａで求められる。透過側空間６３に透過した透過水は透過水ラインＬ２を通って、処理水として処理水タンク７に貯蔵される。濃縮側６２に残った原水は、濃縮水として濃縮水循環ラインＬ５を通って原水タンク２に戻され、ポンプ３によって再び逆浸透膜装置６に送水される。 Next, the pump 3 is started to feed raw water to the reverse osmosis membrane device 6 , and the raw water is treated by the reverse osmosis membrane device 6 . The water supply flow rate and the circulating water flow rate (the flow rate of the concentrated water circulation line L5) are selected so that the minimum required flow rate determined for each type of membrane of the reverse osmosis membrane device 6 is ensured. The flow rate of permeated water (flow rate of the permeated water line L2) is adjusted by the opening of the second valve V2 so as not to deviate from the water flow conditions of the membrane. The second valve V2 may be a constant flow valve or a regulating valve. Alternatively, the permeate flow rate may be controlled by the rotation speed of the pump 3 . Of the boron contained in the raw water, an amount corresponding to the boron rejection rate of the reverse osmosis membrane 61 is removed, and the remainder permeates into the permeation side space 63 . The boron blocking rate is obtained by (AB)/A, where A is the boron concentration in the inlet water of the reverse osmosis membrane device 6 and B is the boron concentration in the outlet water of the reverse osmosis membrane device 6 . The permeated water that permeates the permeate-side space 63 passes through the permeated water line L2 and is stored in the treated water tank 7 as treated water. The raw water remaining on the concentration side 62 is returned to the raw water tank 2 as concentrated water through the concentrated water circulation line L5, and is sent to the reverse osmosis membrane device 6 again by the pump 3.

以上のプロセスを繰り返すに従い、原水タンク２の原水が徐々に減少し、処理水タンク７の処理水が徐々に増えていく。また、濃縮水は原水タンク２に戻されるため、原水タンク２のホウ素濃度は、徐々に高くなる。すなわち、原水中に含まれるホウ素の総量は徐々に減っていくが、原水の量もそれ以上の割合で減っていくため、原水中のホウ素濃度は徐々に増加する。そのため、処理を継続していくに従い、透過水中のホウ素濃度も徐々に増加する。 As the above process is repeated, the raw water in the raw water tank 2 gradually decreases, and the treated water in the treated water tank 7 gradually increases. Further, since the concentrated water is returned to the raw water tank 2, the boron concentration in the raw water tank 2 gradually increases. That is, the total amount of boron contained in raw water gradually decreases, but the amount of raw water also decreases at a rate higher than that, so the boron concentration in raw water gradually increases. Therefore, as the treatment continues, the boron concentration in the permeated water gradually increases.

図２は、原水タンク２の水位、原水タンク２の原水中のホウ素濃度、逆浸透膜装置６の透過水中のホウ素濃度及び処理水タンク７の処理水中の平均ホウ素濃度と、処理時間との関係の計算例を示している。この計算は、ホウ素濃度５００ｍｇ／Ｌ（ｐｐｍ）の原水を原水タンク２に水位３．９ｍ（容積１００００Ｌ）まで供給し、一定の透過水量１．５ｍ^３／ｈで原水を逆浸透膜装置６で処理した場合の計算例である。処理水タンク７の初期水位は０ｍである。逆浸透膜装置６のホウ素阻止率は８０％とした。処理水タンク７の処理水中の平均ホウ素濃度が２００ｍｇ／Ｌ（放水可能なホウ素濃度の基準値の例）に達したときの通水時間は約５．６ｈ、原水タンク２の水位は約０．７ｍ、原水タンク２の原水中のホウ素濃度は約２１００ｍｇ／Ｌ（ｐｐｍ）であった。 FIG. 2 shows the relationship between the water level of the raw water tank 2, the boron concentration in the raw water in the raw water tank 2, the boron concentration in the permeated water of the reverse osmosis membrane device 6, the average boron concentration in the treated water in the treated water tank 7, and the treatment time. shows a calculation example of In this calculation, raw water with a boron concentration of 500 mg / L (ppm) is supplied to the raw water tank 2 up to a water level of 3.9 m (volume 10000 L), and the raw water is supplied to the reverse osmosis membrane device 6 at a constant permeation amount of ^1.5 m / h. It is a calculation example when processed. The initial water level of the treated water tank 7 is 0 m. The boron rejection rate of the reverse osmosis membrane device 6 was set to 80%. When the average boron concentration in the treated water in the treated water tank 7 reached 200 mg/L (an example of the reference value for the boron concentration that can be discharged), the water flow time was about 5.6 hours, and the water level in the raw water tank 2 was about 0.00. 7 m, the concentration of boron in the raw water in the raw water tank 2 was about 2100 mg/L (ppm).

この図からわかるように、処理が進むにつれ原水タンク２の水位（水量）が減少し、原水タンク２の原水中のホウ素濃度、逆浸透膜装置６の透過水中のホウ素濃度、処理水タンク７の処理水中の平均ホウ素濃度が増加していく。ホウ素濃度は原水タンク２で最も大きく、処理水タンク７で最も小さく、逆浸透膜装置６の透過水がその中間である。そして、重要なことは、原水タンク２の水位（水量）、原水タンク２の原水中のホウ素濃度、逆浸透膜装置６の透過水中のホウ素濃度、処理水タンク７の処理水中の平均ホウ素濃度、処理時間は相互に相関しており、いずれか一つが分かれば他の値が推定可能ということである。また、バッチ処理を行っているため、原水タンク２と処理水タンク７の貯蔵水の総量は一定である。従って、原水タンク２の水位（水量）の代わりに、または原水タンク２の水位（水量）とともに、処理水タンク７の水位（水量）を用いることも可能である。 As can be seen from this figure, as the treatment progresses, the water level (water volume) in the raw water tank 2 decreases, the boron concentration in the raw water in the raw water tank 2, the The average boron concentration in the treated water increases. The boron concentration is the highest in the raw water tank 2, the lowest in the treated water tank 7, and the permeated water of the reverse osmosis membrane device 6 is in between. What is important is the water level (water volume) of the raw water tank 2, the boron concentration in the raw water in the raw water tank 2, the boron concentration in the permeated water of the reverse osmosis membrane device 6, the average boron concentration in the treated water in the treated water tank 7, The processing times are mutually correlated, and if one of them is known, the other can be estimated. Further, since batch processing is performed, the total amount of water stored in the raw water tank 2 and the treated water tank 7 is constant. Therefore, it is possible to use the water level (water volume) of the treated water tank 7 instead of the water level (water volume) of the raw water tank 2 or together with the water level (water volume) of the raw water tank 2 .

ホウ素濃度はホウ素濃度計で測定するのが最も確実である。しかし、ホウ素濃度計は非常に高価である。そこで、本実施形態では、ホウ素濃度計の代わりに原水タンク２の水位（水量）、処理水タンク７の水位（水量）、処理時間を濃度相関パラメータとして用いている。処理時間を濃度相関パラメータとして用いる場合、透過処理量が一定であることが必要である。図２の例においては、濃度取得手段１０は、通水時間約５．６ｈ、原水タンク２の水位約０．７ｍ、処理水タンク７の水位約３．２ｍ（３．９ｍ－０．７ｍ）に達したときに、ホウ素濃度が放出可能濃度の上限（２００ｍｇ／Ｌ（ｐｐｍ））に達したと判定する。この時、濃度取得手段１０がアラームを出し、運転員がそれに応じて水処理装置１を停止してもよいし、濃度取得手段１０で取得したホウ素濃度をポンプ３の制御装置に送信し、制御装置がポンプ３を自動停止するようにしてもよい。いずれの場合も、放水基準値に対して余裕を見込み、放水基準値より多少低いホウ素濃度に達したときに水処理装置１のバッチ運転を停止することが好ましい。 Boron concentration is most reliably measured with a boron densitometer. However, boron densitometers are very expensive. Therefore, in this embodiment, the water level (water volume) of the raw water tank 2, the water level (water volume) of the treated water tank 7, and the treatment time are used as concentration correlation parameters instead of the boron concentration meter. If the treatment time is used as the concentration correlation parameter, the permeation throughput should be constant. In the example of FIG. 2, the concentration acquisition means 10 has a water flow time of about 5.6 hours, a water level of the raw water tank 2 of about 0.7 m, and a water level of the treated water tank 7 of about 3.2 m (3.9 m-0.7 m). , it is determined that the boron concentration has reached the upper limit of the releasable concentration (200 mg/L (ppm)). At this time, the concentration acquisition means 10 issues an alarm, and the operator may stop the water treatment apparatus 1 accordingly, or the boron concentration acquired by the concentration acquisition means 10 is transmitted to the control device of the pump 3 and controlled The device may automatically stop the pump 3 . In either case, it is preferable to allow a margin for the water discharge standard value and to stop the batch operation of the water treatment apparatus 1 when the boron concentration reaches a slightly lower level than the water discharge standard value.

上述の制御を行うためには、原水のホウ素濃度をあらかじめ把握しておくことが望ましい。また、ホウ素阻止率に影響する原水の線速度ＬＶ、ｐＨ、温度等も事前に把握することが望ましい。具体的には、まず、原水のホウ素濃度、ｐＨ、温度を測定し、原水の水質を把握する。次に必要とする処理量から逆浸透膜６１の膜面積を設定し、逆浸透膜装置６に供給される原水のＬＶを計算する。次に、これら水質やＬＶの条件から、使用する逆浸透膜６１のホウ素阻止率を設定する。ホウ素阻止率はこれらの条件に対して予め求められている。ホウ素阻止率は、ＬＶやｐＨ、温度により異なるが、通常は５０～９５％程度である。これらの条件から、例えば１時間後の処理水の水量が計算でき、ホウ素阻止率から処理水中のホウ素濃度が計算でき、更に阻止されたホウ素の量から濃縮水中のホウ素濃度が計算できる。２，３，４時間後について同様の計算をすることで、処理水の水量及び処理水に含まれるホウ素の総量が算出でき、処理水中の平均ホウ素濃度が算出できる。この計算をより細かく行えば、より精度を高くすることができる。このようにして、図２に相当する、濃度相関パラメータと処理水中の平均ホウ素濃度との関係を事前に把握し、水処理装置１の運転管理を行うことができる。複数の濃度相関パラメータを複合的に監視し、水処理装置１の運転管理を行ってもよい。 In order to perform the above control, it is desirable to know the boron concentration of raw water in advance. It is also desirable to know in advance the linear velocity LV, pH, temperature, etc. of the raw water that affect the boron rejection rate. Specifically, first, the boron concentration, pH, and temperature of the raw water are measured to determine the quality of the raw water. Next, the membrane area of the reverse osmosis membrane 61 is set from the required throughput, and the LV of the raw water to be supplied to the reverse osmosis membrane device 6 is calculated. Next, the boron blocking rate of the reverse osmosis membrane 61 to be used is set from these water quality and LV conditions. Boron rejection has been previously determined for these conditions. The boron blocking rate varies depending on LV, pH and temperature, but is usually about 50 to 95%. From these conditions, for example, the amount of treated water after 1 hour can be calculated, the boron concentration in the treated water can be calculated from the boron blocking rate, and the boron concentration in the concentrated water can be calculated from the amount of boron blocked. By performing similar calculations after 2, 3, and 4 hours, the amount of treated water and the total amount of boron contained in the treated water can be calculated, and the average boron concentration in the treated water can be calculated. If this calculation is performed more finely, the accuracy can be increased. In this manner, the relationship between the concentration correlation parameter and the average boron concentration in the treated water, which corresponds to FIG. A plurality of concentration correlation parameters may be monitored in combination to manage the operation of the water treatment device 1 .

なお、ホウ素濃度計を用いることも可能である。その場合は、濃度相関パラメータを使う必要はなく、ホウ素濃度計で測定されたホウ素濃度が放水基準値に達したとき、または達する前にバッチ運転を停止する。ホウ素濃度はホウ素濃度計によって常時監視することが好ましい。 It is also possible to use a boron concentration meter. In that case, there is no need to use the concentration correlation parameter, and the batch operation is stopped when or before the boron concentration measured by the boron concentration meter reaches the discharge standard value. The boron concentration is preferably constantly monitored with a boron concentration meter.

水処理装置１のバッチ運転が終了したら（すなわち、濃度取得手段１０で取得されたホウ素濃度が所定の値に達したら）、第３の弁Ｖ３を開き、処理水タンク７に貯留された処理水の少なくとも一部（本実施形態では全量）を処理水タンク７から排出する。処理水タンク７の処理水は、別の処理水槽（図示せず）へ送水して、水質を確認後放出してもよいし、排水処理設備（図示せず）に送水してもよい。これと同時に、またはこれと前後して、第４の弁Ｖ４を開き、原水タンク２に貯留された水（濃縮水）の少なくとも一部（本実施形態では全量）を原水タンク２から排出する。濃縮水は濃縮水槽（図示せず）に送り、凝集沈殿処理を行う。ホウ素濃度が高められているため、効率よく処理ができる。または、濃縮水を蒸発濃縮装置を用いて濃縮して、処理水の更なる濃縮を行ってもよい。濃縮水が既に濃縮減容化されているため、凝集沈殿処理装置や蒸発濃縮装置の設備規模や運転コストを低減することができる。蒸発濃縮処理の後、固化処理を行ってもよい。 When the batch operation of the water treatment device 1 is completed (that is, when the boron concentration obtained by the concentration obtaining means 10 reaches a predetermined value), the third valve V3 is opened, and the treated water stored in the treated water tank 7 At least a portion of (the entire amount in this embodiment) is discharged from the treated water tank 7 . The treated water in the treated water tank 7 may be sent to another treated water tank (not shown) and discharged after checking the water quality, or may be sent to a waste water treatment facility (not shown). Simultaneously with this, or before or after this, the fourth valve V4 is opened, and at least a portion (in this embodiment, the entire amount) of the water (concentrated water) stored in the raw water tank 2 is discharged from the raw water tank 2. The concentrated water is sent to a concentrated water tank (not shown) and subjected to coagulation sedimentation treatment. Since the boron concentration is increased, the treatment can be performed efficiently. Alternatively, the concentrated water may be concentrated using an evaporative concentration device to further concentrate the treated water. Since the concentrated water has already been concentrated and reduced in volume, it is possible to reduce the equipment scale and operating costs of the coagulating sedimentation treatment apparatus and the evaporative concentration apparatus. A solidification treatment may be performed after the evaporative concentration treatment.

次に本実施形態の効果について説明する。ホウ素を含む透過水を放水する場合、ホウ素濃度が放水基準値を上回ると放水が不可能となる。本実施形態の水処理装置１は再循環方式を用いているため、上述したように逆浸透膜６１の透過水中のホウ素濃度は徐々に増加する。ここで、本実施形態から処理水タンク７を省略したものを比較例とする。比較例では、ホウ素濃度が放水基準値を超えていないことを確認しながら、逆浸透膜装置６の透過水を順次放水する。この場合、図２において、４ｈ程度の時間が経過すると、逆浸透膜装置６の透過水中のホウ素濃度が放水基準値（２００ｐｐｍ）に達し、放水ができなくなる。 Next, the effects of this embodiment will be described. When permeated water containing boron is discharged, discharge becomes impossible if the concentration of boron exceeds the standard value for discharged water. Since the water treatment apparatus 1 of this embodiment uses the recirculation system, the concentration of boron in the permeated water of the reverse osmosis membrane 61 gradually increases as described above. Here, a comparative example is obtained by omitting the treated water tank 7 from the present embodiment. In the comparative example, the permeated water of the reverse osmosis membrane device 6 is sequentially discharged while confirming that the boron concentration does not exceed the water discharge standard value. In this case, in FIG. 2, after about 4 hours have passed, the concentration of boron in the permeated water of the reverse osmosis membrane device 6 reaches the water discharge standard value (200 ppm), and water discharge becomes impossible.

これに対して、本実施形態では、逆浸透膜装置６の透過水を一旦処理水タンク７に溜めている。処理水タンク７の処理水中のホウ素濃度は処理開始後の初期段階では低いため、後から処理水タンク７に流入した、ホウ素濃度の高い透過水が、先に処理水タンク７に流入した、ホウ素濃度の低い透過水によって、いわば「希釈」ないし「平均化」される。この結果、処理水タンク７の処理水中の平均ホウ素濃度は、平均ホウ素濃度算出時における逆浸透膜装置６の透過水中のホウ素濃度と比べて、低い値に抑えられる。それでも、逆浸透膜装置６の透過水中のホウ素濃度は徐々に増加するので、処理水タンク７の処理水中の平均ホウ素濃度も徐々に増加するが、放水基準値（２００ｐｐｍ）に達するのは、前述の通り５．６ｈ後である。従って、比較例では約４ｈ分の透過水しか放水できないのに対し、本実施形態では５．６ｈ分、つまり約４割多い透過水を、規制を遵守しつつ、放水することが可能となる。換言すれば、ホウ素濃度が放水基準値を超えた透過水も、「希釈」ないし「平均化」することによって放水が可能となる。また、逆浸透膜装置６の透過水中のホウ素濃度が放水基準値を超えても水処理装置１の運転を継続することができ、比較例よりも長時間バッチ運転を行える結果、原水タンク２の水位が低下し、濃縮水のさらなる減容化が可能となる。原水中に含まれるホウ素以外の成分も、逆浸透膜装置６で阻止可能な成分であれば、濃縮水側に残すことができる。濃縮水が減容化されているため、当該成分の回収や後処理が必要である場合に、回収や後処理の負荷を低減できる。 On the other hand, in this embodiment, the permeated water of the reverse osmosis membrane device 6 is once stored in the treated water tank 7 . Since the boron concentration in the treated water in the treated water tank 7 is low in the initial stage after the start of treatment, the permeated water with a high boron concentration that flows into the treated water tank 7 later flows into the treated water tank 7 first. It is, so to speak, "diluted" or "averaged" by the low-concentration permeate. As a result, the average boron concentration in the treated water of the treated water tank 7 is suppressed to a lower value than the boron concentration in the permeated water of the reverse osmosis membrane device 6 when calculating the average boron concentration. Still, since the boron concentration in the permeated water of the reverse osmosis membrane device 6 gradually increases, the average boron concentration in the treated water of the treated water tank 7 also gradually increases, but the discharge standard value (200 ppm) is reached as described above. 5.6 hours later. Therefore, while the comparative example can discharge only about 4 hours of permeated water, the present embodiment can discharge 5.6 hours of permeated water, that is, about 40% more permeated water, while complying with regulations. In other words, even the permeated water whose boron concentration exceeds the water discharge standard value can be discharged by "diluting" or "averaging". In addition, even if the boron concentration in the permeated water of the reverse osmosis membrane device 6 exceeds the water discharge standard value, the operation of the water treatment device 1 can be continued, and the batch operation can be performed for a longer time than in the comparative example. The water level will drop, making it possible to further reduce the volume of the concentrated water. Components other than boron contained in the raw water can be left in the concentrated water side as long as they can be blocked by the reverse osmosis membrane device 6 . Since the concentrated water is reduced in volume, the burden of recovery and post-treatment can be reduced when recovery and post-treatment of the component are required.

逆浸透膜装置でホウ素含有水を処理する際にホウ素が逆浸透膜を透過することは、これまでも知られており、従来はホウ素除去率の向上を課題として、装置や素材の開発が行われてきた。しかし、ホウ素が透過することを許容した上で、透過水中のホウ素濃度を調整するという発想はこれまでになかったものである。また、透過水中のホウ素濃度が放水基準値を超えた後に水処理装置１の運転継続を許容するという発想もなかった。本実施形態は、処理水タンク７を設置し、処理水タンク７の処理水中の平均ホウ素濃度を放水基準値に収めるという新規な発想に基づくものである。この結果、逆浸透膜装置６の透過水中のホウ素濃度が放水基準値を超えた後に、その透過水に含まれるホウ素を別処理で除去したり、透過水を純水等で希釈して目的の濃度に調整したりする必要がなくなる。本実施形態は、処理水タンク７を設けるだけでよいので、コストへの影響も限定的である。 It has been known that boron permeates the reverse osmosis membrane when treating boron-containing water with a reverse osmosis membrane device, and conventionally, devices and materials have been developed with the goal of improving the boron removal rate. It's been broken However, the concept of adjusting the concentration of boron in the permeated water while allowing permeation of boron has never been done before. Moreover, there was no concept of permitting the continued operation of the water treatment apparatus 1 after the concentration of boron in the permeated water exceeds the discharge standard value. This embodiment is based on a novel idea of installing a treated water tank 7 and setting the average boron concentration in the treated water in the treated water tank 7 within the water discharge standard value. As a result, after the boron concentration in the permeated water of the reverse osmosis membrane device 6 exceeds the discharge standard value, the boron contained in the permeated water is removed by separate treatment, or the permeated water is diluted with pure water or the like to obtain the desired concentration. There is no need to adjust the concentration. In this embodiment, only the treated water tank 7 needs to be provided, so the impact on cost is also limited.

（第２の実施形態）
図３に、本発明の第２の実施形態に係る水処理装置１の概略構成を示す。水処理装置１は、処理水タンク７に接続されたイオン交換装置１１を有している。処理水タンク７とイオン交換装置１１は処理水循環ラインＬ６で接続され、処理水タンク７に貯留された処理水が処理水循環ラインＬ６に沿って、イオン交換装置１１との間で循環する。これによって、処理水に含まれるホウ素をイオン交換樹脂に吸着させ、処理水中のホウ素濃度を低減することができる。処理水を放出する際は、ホウ素濃度が放出基準値を満たしていることを最終確認することが望ましいが、万が一ホウ素濃度が放出基準値を上回った場合は、イオン交換装置１１で処理水中のホウ素濃度を放出基準値以下まで下げてから放出する。ホウ素濃度は連続的に監視する必要がないため、処理水タンク７の処理水をサンプリングして、市販のホウ素濃度測定キット等を用いて測定することができる（高価なホウ素濃度計は不要である）。イオン交換装置１１に充填するイオン交換樹脂は、陰イオン交換樹脂であれば特に限定されないが、多価アルコールの官能基を持った塩基性陰イオン交換樹脂（例えば、Ｄｕｐｏｎｔ社製ＩＲＡ－７４３）等の、ホウ素を選択的に吸着するものが好ましい。イオン交換装置１１は常時運転するものではなく、処理水中のホウ素濃度が放出基準値を上回った場合に一時的に運転するだけであるため、非再生型が好ましい。再生型を用いると再生設備が必要となり、水処理装置１が複雑となり、コストも高くなる。 (Second embodiment)
FIG. 3 shows a schematic configuration of a water treatment device 1 according to a second embodiment of the present invention. The water treatment device 1 has an ion exchanger 11 connected to a treated water tank 7 . The treated water tank 7 and the ion exchange device 11 are connected by a treated water circulation line L6, and the treated water stored in the treated water tank 7 circulates between the ion exchange device 11 and the treated water circulation line L6. As a result, boron contained in the treated water can be adsorbed on the ion exchange resin, and the boron concentration in the treated water can be reduced. When discharging the treated water, it is desirable to make a final confirmation that the boron concentration satisfies the release standard value. Release after reducing the concentration to below the release standard value. Since there is no need to continuously monitor the boron concentration, the treated water in the treated water tank 7 can be sampled and measured using a commercially available boron concentration measurement kit (an expensive boron concentration meter is not required. ). The ion exchange resin to be filled in the ion exchange device 11 is not particularly limited as long as it is an anion exchange resin, but a basic anion exchange resin having a polyhydric alcohol functional group (eg, IRA-743 manufactured by Dupont) or the like. Of these, those that selectively adsorb boron are preferred. The ion exchanger 11 is preferably non-regenerative type because it is not always operated, but only temporarily operated when the boron concentration in the treated water exceeds the release standard value. Use of the regenerative type requires regenerative equipment, complicates the water treatment apparatus 1, and increases the cost.

（第３の実施形態）
図４に、本発明の第３の実施形態に係る水処理装置１の概略構成を示す。本実施形態の水処理装置１は、直列に接続された複数の逆浸透膜装置６Ａ，６Ｂを有する。以降の各実施形態において、逆浸透膜装置６Ａ，６Ｂのそれぞれに対応するポンプ３、フィルタ４、ｐＨ調整手段５、熱交換器１３、弁等がある場合、図面中の符号にＡ，Ｂを追加して説明を省略する場合がある。 (Third Embodiment)
FIG. 4 shows a schematic configuration of a water treatment device 1 according to a third embodiment of the present invention. The water treatment device 1 of this embodiment has a plurality of reverse osmosis membrane devices 6A and 6B connected in series. In the following embodiments, when there are pumps 3, filters 4, pH adjusting means 5, heat exchangers 13, valves, etc. corresponding to the reverse osmosis membrane devices 6A and 6B, A and B are added to the symbols in the drawings. Additional description may be omitted.

原水のホウ素濃度が高い場合、１段の逆浸透膜処理ではホウ素濃度を十分に下げることができない可能性がある。本実施形態では２段の逆浸透膜装置６Ａ，６Ｂを設けているため、１段当たりのホウ素阻止率が８０％の場合、２段の逆浸透膜装置６Ａ，６Ｂ全体でのホウ素阻止率は９６％となり、ホウ素阻止率の大幅な向上が可能である。逆浸透膜装置６Ａ，６Ｂの段数は限定されない。逆浸透膜装置６Ａと逆浸透膜装置６Ｂとの間に中間貯蔵タンク１２が設けられている。中間貯蔵タンク１２は上流側の逆浸透膜装置６Ａの透過水を貯蔵し、下流側の逆浸透膜装置６Ｂに透過水を送水する。中間貯蔵タンク１２は逆浸透膜装置６Ａと逆浸透膜装置６Ｂの透過水量の差を吸収することができるため、水処理装置１の制御を容易にする。中間貯蔵タンク１２は省略することもできる。２段の逆浸透膜装置６Ａ，６Ｂの濃縮水はそれぞれの濃縮水循環ラインＬ５Ａ，Ｌ５Ｂを通って原水タンク２に戻されるが、後段の逆浸透膜装置６Ｂの濃縮水の一部を中間貯蔵タンク１２に戻し、残りを原水タンク２に戻すことも可能である。この目的で、濃縮水循環ラインＬ５Ｂから分岐して中間貯蔵タンク１２に接続される濃縮水戻りラインＬ７が設けられている。濃縮水戻りラインＬ７は省略することもできる。 If the raw water has a high boron concentration, it may not be possible to sufficiently lower the boron concentration with a single-stage reverse osmosis membrane treatment. In this embodiment, since the two-stage reverse osmosis membrane devices 6A and 6B are provided, when the boron rejection rate per stage is 80%, the boron rejection rate of the entire two-stage reverse osmosis membrane devices 6A and 6B is It is 96%, and a significant improvement in the boron rejection rate is possible. The number of stages of the reverse osmosis membrane devices 6A, 6B is not limited. An intermediate storage tank 12 is provided between the reverse osmosis membrane device 6A and the reverse osmosis membrane device 6B. The intermediate storage tank 12 stores the permeated water of the reverse osmosis membrane device 6A on the upstream side and sends the permeated water to the reverse osmosis membrane device 6B on the downstream side. The intermediate storage tank 12 can absorb the difference in the amount of permeated water between the reverse osmosis membrane device 6A and the reverse osmosis membrane device 6B, thus facilitating the control of the water treatment device 1 . The intermediate storage tank 12 can also be omitted. The concentrated water from the two-stage reverse osmosis membrane devices 6A and 6B is returned to the raw water tank 2 through the respective concentrated water circulation lines L5A and L5B, but part of the concentrated water from the latter-stage reverse osmosis membrane device 6B is stored in the intermediate storage tank. 12 and the remainder to the raw water tank 2. For this purpose, a concentrated water return line L7 branched from the concentrated water circulation line L5B and connected to the intermediate storage tank 12 is provided. The concentrated water return line L7 can also be omitted.

図５に、第３の実施形態の第１の変形例に係る水処理装置１の概略構成を示す。本変形例の水処理装置１は、第１の実施形態の水処理装置１を一つのユニットとしたときに、複数のユニットＵＡ，ＵＢを直列に配置した構成となっている。ただし、１段目のユニットＵＡの処理水タンク７と２段目のユニットＵＢの原水タンク２は中間貯蔵タンク１２に統合されている。すなわち、複数の逆浸透膜装置６Ａ，６Ｂの間に中間貯蔵タンク１２が配置されている。中間貯蔵タンク１２は中間貯蔵タンク１２の上流側の逆浸透膜装置６Ａの透過水を貯留するとともに、中間貯蔵タンク１２の下流側の逆浸透膜装置６Ｂに透過水を送水する。中間貯蔵タンク１２の水位は、中間貯蔵タンク１２に設けられた第３の水位計１３（濃度相関パラメータの測定手段）で測定される。１段目のユニットＵＡは第３の弁Ｖ３を有しておらず、２段目のユニットＵＢは第１の弁Ｖ１を有していない。 FIG. 5 shows a schematic configuration of a water treatment device 1 according to a first modified example of the third embodiment. The water treatment apparatus 1 of this modification has a configuration in which a plurality of units UA and UB are arranged in series when the water treatment apparatus 1 of the first embodiment is made into one unit. However, the treated water tank 7 of the unit UA on the first stage and the raw water tank 2 of the unit UB on the second stage are integrated into the intermediate storage tank 12 . That is, the intermediate storage tank 12 is arranged between the multiple reverse osmosis membrane devices 6A and 6B. The intermediate storage tank 12 stores the permeated water of the reverse osmosis membrane device 6A on the upstream side of the intermediate storage tank 12 and sends the permeated water to the reverse osmosis membrane device 6B on the downstream side of the intermediate storage tank 12 . The water level of the intermediate storage tank 12 is measured by a third water level gauge 13 (concentration correlation parameter measuring means) provided in the intermediate storage tank 12 . The first stage unit UA does not have the third valve V3, and the second stage unit UB does not have the first valve V1.

１段目のユニットＵＡと２段目のユニットＵＢは選択的に稼働する。図５は１段目のユニットＵＡが稼働し、２段目のユニットＵＢが停止している状態を示している。１段目のユニットＵＡが稼働する場合は、第１の弁Ｖ１Ａと第４の弁Ｖ４Ａを閉め、第２の弁Ｖ２Ａを開く。２段目のユニットＵＢの第２～第４の弁Ｖ２Ｂ,Ｖ３,Ｖ４Ｂは閉めておく（但し、第３の弁Ｖ３は開いていてもよい）。これによって、１段目のユニットＵＡは外部と水の出入りがない状態となる。１段目のユニットＵＡを運転することで、中間処理水が中間貯蔵タンク１２に貯蔵される。中間貯蔵タンク１２の中間処理水中の平均ホウ素濃度の目安値は、原水中のホウ素濃度、放出基準値、逆浸透膜装置６Ａのホウ素阻止率等から予め求めておき、平均ホウ素濃度が目安値に達したときに１段目のユニットＵＡの運転を停止する。濃度取得手段１０Ａは、濃度相関パラメータの測定手段８，１３の測定値を中間貯蔵タンク１２の処理水中のホウ素濃度に換算する。 The unit UA on the first stage and the unit UB on the second stage are selectively operated. FIG. 5 shows a state in which the unit UA on the first stage is in operation and the unit UB on the second stage is stopped. When the unit UA of the first stage operates, the first valve V1A and the fourth valve V4A are closed and the second valve V2A is opened. The second to fourth valves V2B, V3, V4B of the second stage unit UB are closed (however, the third valve V3 may be open). As a result, the first-stage unit UA is in a state where water does not flow in and out of the outside. Intermediate treated water is stored in the intermediate storage tank 12 by operating the first stage unit UA. The standard value of the average boron concentration in the intermediate treated water of the intermediate storage tank 12 is obtained in advance from the boron concentration in the raw water, the release standard value, the boron rejection rate of the reverse osmosis membrane device 6A, etc., and the average boron concentration reaches the standard value. When it reaches, the operation of the first stage unit UA is stopped. The concentration acquisition means 10A converts the measured values of the concentration correlation parameter measurement means 8 and 13 into the boron concentration in the treated water in the intermediate storage tank 12 .

次に、２段目のユニットＵＢの第２の弁Ｖ２Ｂを開く（第３の弁Ｖ３が開いている場合は閉める）。これによって、２段目のユニットＵＢは外部と水の出入りがない状態となる。そして、２段目のユニットＵＢを１段目のユニットＵＡと同様に運転する。処理水タンク７の処理水中の平均ホウ素濃度が目安値に達したとき、またはその前に２段目のユニットＵＢの運転を停止する。濃度取得手段１０Ｂは、濃度相関パラメータの測定手段９，１３の測定値を処理水タンク７の処理水中のホウ素濃度に換算する。その後、第３の弁Ｖ３を開き、処理水タンク７から処理水を放出する。 Next, the second valve V2B of the second stage unit UB is opened (if the third valve V3 is open, it is closed). As a result, the second-stage unit UB is in a state where water does not flow in and out of the outside. Then, the second stage unit UB is operated in the same manner as the first stage unit UA. When or before the average boron concentration in the treated water in the treated water tank 7 reaches a reference value, the operation of the second stage unit UB is stopped. The concentration acquisition means 10B converts the measured values of the concentration correlation parameter measurement means 9 and 13 into the boron concentration in the treated water in the treated water tank 7 . After that, the third valve V3 is opened to discharge the treated water from the treated water tank 7 .

本変形例も、直列に接続された複数の逆浸透膜装置６Ａ，６Ｂを有しているので、第３の実施形態と同様の効果を奏する。本変形例では、２段目のユニットＵＢの運転中に１段目のユニットＵＡの原水タンク２に原水を供給することができるので、１段目のユニットＵＡへの切り替え後、速やかに１段目のユニットＵＡの運転を開始できる。また、１段目（２段目）のユニットＵＡ（ＵＢ）からの濃縮水の取り出しは２段目（１段目）のユニットＵＢ（ＵＡ）の運転中に可能であるので、濃縮水の取り出しが水処理装置１の稼働率を下げることもない。 Since this modification also has a plurality of reverse osmosis membrane devices 6A and 6B connected in series, it has the same effect as the third embodiment. In this modification, raw water can be supplied to the raw water tank 2 of the first-stage unit UA while the second-stage unit UB is in operation. Operation of the second unit UA can be started. In addition, since it is possible to take out the concentrated water from the first-stage (second-stage) unit UA (UB) while the second-stage (first-stage) unit UB (UA) is in operation, However, the operation rate of the water treatment device 1 is not lowered.

図６に、第３の実施形態の第２の変形例に係る水処理装置１の概略構成を示す。本変形例の水処理装置１は、複数の逆浸透膜装置６の間に直列に配置された２つの中間貯蔵タンク１２Ａ，１２Ｂを有している。上流側の中間貯蔵タンク１２Ａは第１の実施形態の処理水タンク７に相当し、下流側の中間貯蔵タンク１２Ｂは第１の実施形態の原水タンク２に相当する。上流側の中間貯蔵タンク１２Ａは、その上流側の逆浸透膜装置６Ａの透過水を貯留し、下流側の中間貯蔵タンク１２Ｂは、その下流側の逆浸透膜装置６Ｂに透過水を送水する。つまり、本変形例も、第１の実施形態の水処理装置１を一つのユニットとしたときに、複数のユニットＵＡ，ＵＢを直列に配置した構成となっている。 FIG. 6 shows a schematic configuration of a water treatment device 1 according to a second modification of the third embodiment. The water treatment device 1 of this modified example has two intermediate storage tanks 12A and 12B arranged in series between a plurality of reverse osmosis membrane devices 6 . The upstream intermediate storage tank 12A corresponds to the treated water tank 7 of the first embodiment, and the downstream intermediate storage tank 12B corresponds to the raw water tank 2 of the first embodiment. The upstream intermediate storage tank 12A stores the permeated water of the upstream reverse osmosis membrane device 6A, and the downstream intermediate storage tank 12B sends the permeated water to the downstream reverse osmosis membrane device 6B. That is, this modification also has a configuration in which a plurality of units UA and UB are arranged in series when the water treatment apparatus 1 of the first embodiment is made into one unit.

本変形例の水処理装置１は第１の変形例の水処理装置１と同様に作動する。ただし、上流側の中間貯蔵タンク１２Ａと下流側の中間貯蔵タンク１２Ｂとの間の第３の弁Ｖ３Ａを閉じることで、１段目のユニットＵＡと２段目のユニットＵＢを同時に運転することができる。１段目のユニットＵＡの中間貯蔵タンク１２Ａの処理水中のホウ素濃度が所定の目安に達したら、１段目のユニットＵＡの運転を停止する。そして、第３の弁Ｖ３Ａを開き、処理水を２段目のユニットＵＢの中間貯蔵タンク１２Ｂに移送する。２段目のユニットＵＢは運転を開始し、１段目のユニットＵＡの中間貯蔵タンク１２Ａに貯蔵されていた処理水の処理を行う。２段目のユニットＵＢの処理水タンク７の処理水中のホウ素濃度が所定の目安に達したら、２段目のユニットＵＢの運転を停止する。この間、１段目のユニットＵＡは新たな原水を受け入れ、運転を開始し、新たな原水の処理を行う。この様にして、１段目のユニットＵＡと２段目のユニットＵＢを同時に運転することができるため、処理効率が大きく向上する。１段目のユニットＵＡと２段目のユニットＵＢは同じタイミングで運転を開始し、運転を停止することが好ましい。 The water treatment device 1 of this modified example operates in the same manner as the water treatment device 1 of the first modified example. However, by closing the third valve V3A between the upstream intermediate storage tank 12A and the downstream intermediate storage tank 12B, the first stage unit UA and the second stage unit UB can be operated simultaneously. can. When the concentration of boron in the treated water in the intermediate storage tank 12A of the first stage unit UA reaches a predetermined standard, the operation of the first stage unit UA is stopped. Then, the third valve V3A is opened to transfer the treated water to the intermediate storage tank 12B of the second stage unit UB. The second-stage unit UB starts operation and treats the treated water stored in the intermediate storage tank 12A of the first-stage unit UA. When the concentration of boron in the treated water in the treated water tank 7 of the second-stage unit UB reaches a predetermined standard, the operation of the second-stage unit UB is stopped. During this time, the first-stage unit UA receives new raw water, starts operation, and processes the new raw water. In this manner, the first-stage unit UA and the second-stage unit UB can be operated at the same time, thereby greatly improving the processing efficiency. It is preferable that the first-stage unit UA and the second-stage unit UB start operating and stop operating at the same timing.

（第４の実施形態）
図７に、本発明の第４の実施形態に係る水処理装置１の概略構成を示す。本実施形態の水処理装置１は、第１の実施形態の水処理装置１を一つのユニットとしたときに、複数のユニットＵＡ，ＵＢを並列に配置した構成となっている。１段目のユニットＵＡと２段目のユニットＵＢはそれぞれ、原水タンク２Ａ,２Ｂと、少なくとも一つの逆浸透膜装置６Ａ,６Ｂと、濃縮水循環ラインＬ５Ａ，Ｌ５Ｂと、処理水タンク７Ａ，７Ｂと、原水供給ラインＬ１Ａ，Ｌ１Ｂと、原水供給ラインＬ１Ａ，Ｌ１Ｂに設けられた第１の弁Ｖ１Ａ，Ｖ１Ｂと、を有している。水処理装置１は、原水の主供給ラインＬ８を有し、主供給ラインＬ８が１段目のユニットＵＡの供給ラインＬ１Ａと、２段目のユニットＵＢの原水の供給ラインＬ１Ｂに接続されている。 (Fourth embodiment)
FIG. 7 shows a schematic configuration of a water treatment device 1 according to a fourth embodiment of the present invention. The water treatment apparatus 1 of this embodiment has a configuration in which a plurality of units UA and UB are arranged in parallel when the water treatment apparatus 1 of the first embodiment is made into one unit. The first-stage unit UA and the second-stage unit UB respectively include raw water tanks 2A and 2B, at least one reverse osmosis membrane device 6A and 6B, concentrated water circulation lines L5A and L5B, and treated water tanks 7A and 7B. , raw water supply lines L1A and L1B, and first valves V1A and V1B provided in the raw water supply lines L1A and L1B. The water treatment apparatus 1 has a main supply line L8 of raw water, and the main supply line L8 is connected to the supply line L1A of the unit UA on the first stage and to the supply line L1B of the raw water of the unit UB on the second stage. .

本実施形態の水処理装置１では、１段目のユニットＵＡと２段目のユニットＵＢは完全に独立して運転することができる。例えば、１段目のユニットＵＡの運転中は２段目のユニットＵＢが原水を受け入れ、２段目のユニットＵＢの運転中は１段目のユニットＵＡが原水を受け入れるようにすることができる。これによって、水処理装置１全体としては、常に原水を受け入れることができるので、実質的に連続処理が可能となる。この場合、複数のユニットＵＡ，ＵＢの第１の弁Ｖ１Ａ，Ｖ１Ｂは同時に一つしか開かない。また、一時的に大量の原水が発生する場合は１段目のユニットＵＡと２段目のユニットＵＢが同時に原水を受け入れるようにすることができる。本実施形態は１段目のユニットＵＡと２段目のユニットＵＢが相互に影響しないため、原水の発生状況に合わせて様々な運転方法が可能である。 In the water treatment apparatus 1 of this embodiment, the unit UA on the first stage and the unit UB on the second stage can be operated completely independently. For example, the second-stage unit UB may receive raw water while the first-stage unit UA is in operation, and the first-stage unit UA may receive raw water while the second-stage unit UB is in operation. As a result, the water treatment apparatus 1 as a whole can receive raw water at all times, so that it is possible to perform substantially continuous treatment. In this case, only one of the first valves V1A, V1B of the plurality of units UA, UB is opened at the same time. Also, when a large amount of raw water is temporarily generated, the unit UA on the first stage and the unit UB on the second stage can receive the raw water at the same time. In this embodiment, since the first-stage unit UA and the second-stage unit UB do not affect each other, various operation methods are possible according to the generation of raw water.

以上本発明のいくつかの実施形態によって説明したが、本発明はこれらの実施形態に限定されない。例えば、濃縮水の戻し先を原水タンク２の上流側の原水槽とすることもできる。原水槽が十分に大きく、仮に濃縮水を原水槽に戻しても、原水タンク２に供給される原水中のホウ素濃度が大きく変動しない場合は、このような構成も可能である。また、第１～第４の実施形態（第１、第２の変形例も含む）は相互に組み合わせることが可能である。例えば、第２の実施形態のイオン交換装置１１は他の任意の実施形態または変形例と組み合わせることができる。個々のユニットＵＡ，ＵＢを第３の実施形態またはその変形例（図４～６）に示すように構成し、これらのユニットＵＡ，ＵＢを第４の実施形態（図７）に示すように並列に組み合わせることができる。この場合、複数の逆浸透膜装置６Ａ,６Ｂが各々直列接続された複数のユニットＵＡ，ＵＢが並列に接続されるため、ホウ素濃度の高い原水を高効率で処理することができる。 Although several embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, the concentrated water can be returned to the raw water tank on the upstream side of the raw water tank 2 . Such a configuration is also possible when the raw water tank is sufficiently large and even if the concentrated water is returned to the raw water tank, the boron concentration in the raw water supplied to the raw water tank 2 does not change significantly. Also, the first to fourth embodiments (including the first and second modifications) can be combined with each other. For example, the ion exchange device 11 of the second embodiment can be combined with any other embodiment or modification. Individual units UA and UB are configured as shown in the third embodiment or its modifications (FIGS. 4-6), and these units UA and UB are arranged in parallel as shown in the fourth embodiment (FIG. 7). can be combined with In this case, since a plurality of units UA and UB each having a plurality of reverse osmosis membrane devices 6A and 6B connected in series are connected in parallel, raw water with a high boron concentration can be treated with high efficiency.

１水処理装置
２原水タンク
６，６Ａ，６Ｂ逆浸透膜装置
７、７Ａ，７Ｂ処理水タンク
８，９，８Ａ，８Ｂ，９Ａ，９Ｂ，１３濃度相関パラメータの測定手段
１０濃度取得手段
１１イオン交換装置
１２、１２Ａ，１２Ｂ中間貯蔵タンク
１３、１３Ａ、１３Ｂ熱交換器
Ｌ５、Ｌ５Ａ，Ｌ５Ｂ濃縮水循環ライン
Ｌ６処理水循環ライン
Ｌ７濃縮水戻りライン
Ｌ８原水の主供給ライン
Ｖ１～Ｖ４弁 1 water treatment device 2 raw water tank 6, 6A, 6B reverse osmosis membrane device 7, 7A, 7B treated water tank 8, 9, 8A, 8B, 9A, 9B, 13 concentration correlation parameter measurement means 10 concentration acquisition means 11 ion exchange Apparatus 12, 12A, 12B Intermediate storage tank 13, 13A, 13B Heat exchanger L5, L5A, L5B Concentrated water circulation line L6 Treated water circulation line L7 Concentrated water return line L8 Raw water main supply line V1 to V4 Valve

Claims

A raw water tank for storing raw water containing a predetermined substance;
at least one reverse osmosis membrane device for separating raw water fed from the raw water tank into permeated water and concentrated water;
a concentrated water circulation line returning the concentrated water to the raw water tank;
A treated water tank for storing the permeated water as treated water;
a concentration acquiring means for acquiring the concentration of the predetermined substance in the treated water stored in the treated water tank;
A water treatment apparatus, wherein at least part of the treated water stored in the treated water tank is discharged from the treated water tank when the concentration obtained by the concentration obtaining means reaches a predetermined value.

2. The water treatment according to claim 1, wherein at least part of the water stored in said raw water tank is discharged from said raw water tank when said concentration obtained by said concentration obtaining means reaches said predetermined value. Device.

measuring means for measuring a concentration correlation parameter that correlates with the concentration of the predetermined substance in the treated water stored in the treated water tank;
The concentration obtaining means determines whether the concentration of the predetermined substance in the treated water stored in the treated water tank has reached the predetermined value based on the concentration correlation parameter measured by the measuring means. 3. The water treatment device according to claim 1 or 2, wherein the water treatment device determines.

4. The water treatment apparatus according to claim 3, wherein said concentration correlation parameter is at least one of the amount of water in said raw water tank, the amount of water in said treated water tank, and the elapsed time after starting treatment in said reverse osmosis membrane apparatus.

an ion exchange device;
A treated water circulation line that connects the treated water tank and the ion exchange device and circulates the treated water stored in the treated water tank between the ion exchange device and the treated water tank;
The water treatment device according to any one of claims 1 to 4, comprising:

6. The water treatment system according to any one of claims 1 to 5, wherein said at least one reverse osmosis membrane device comprises a plurality of reverse osmosis membrane devices connected in series.

An intermediate storage tank is provided between the plurality of reverse osmosis membrane devices, and the intermediate storage tank stores the permeated water of the reverse osmosis membrane device on the upstream side of the intermediate storage tank, and the downstream side of the intermediate storage tank. 7. The water treatment apparatus according to claim 6, wherein said permeated water is fed to said reverse osmosis membrane apparatus of.

having two intermediate storage tanks arranged in series between the plurality of reverse osmosis membrane devices, wherein the upstream intermediate storage tank permeates the reverse osmosis membrane device upstream of the upstream intermediate storage tank; 7. The water treatment apparatus according to claim 6, wherein water is stored, and said downstream intermediate storage tank feeds said permeated water to said reverse osmosis membrane apparatus downstream of said downstream intermediate storage tank.

a main supply line for the raw water;
The raw water tank, the at least one reverse osmosis membrane device, the concentrated water circulation line, the treated water tank, a raw water supply line to the raw water tank, and a valve provided in the supply line, respectively. a plurality of units having
9. A water treatment apparatus as claimed in any preceding claim, wherein the main supply line is connected to the supply lines of the plurality of units.

10. A water treatment device according to any one of claims 1 to 9, wherein said predetermined substance is boron.