JP2004313985A

JP2004313985A - Method for treating volatile organic compound and apparatus for the same

Info

Publication number: JP2004313985A
Application number: JP2003113670A
Authority: JP
Inventors: Yasuhiro Kato; 康弘加藤
Original assignee: Fuji Electric Systems Co Ltd
Current assignee: Fuji Electric Co Ltd
Priority date: 2003-04-18
Filing date: 2003-04-18
Publication date: 2004-11-11

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems that a method of directly bringing gaseous ozone into an object to be treated to bring the gaseous ozone into contact therewith, or a method of performing decomposition and removal by separating the objective substance to be treated into a gaseous phase, then bringing the objective substance to be treated into contact with the ozone and further a method of adsorbing a volatile organic substance in an adsorbent, then performing oxidation decomposition treatment in the treatment of the object to be treated containing the volatile organic compound are low in the efficiency of utilizing the ozone and therefore upsizing of an ozone generator and an increase of an equipment cost and running cost are resulted. <P>SOLUTION: The treatment method has a process of separating the volatile organic compound from the object to be treated and adsorbing the compound to thicken the compound and a process of adsorbing the gaseous ozone to thicken the compound, in which the treatment is performed by bringing the thickened volatile organic compound and the thickened ozone into contact after respectively thickening the volatile organic compound and the ozone. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、オゾンを用いた揮発性有機化合物の酸化分解処理に関する。
【０００２】
【従来の技術】
近年では、特に土壌・地下水におけるトリクロロエチレン、テトラクロロエチレン等の揮発性有機塩素化合物による汚染が深刻化しており、これら揮発性有機塩素化合物は難分解性であることから、オゾンの持つ強力な酸化力を利用した浄化装置が広く用いられている。
土壌・地下水中の例えばトリクロロエチレンやテトラクロロエチレンの処理において、オゾン処理を適用する場合には、大別して、以下の２通りの処理方式が用いられている。
【０００３】
第１は、汚染土壌や地下水にオゾンガスを直接吹き込み、接触させることで処理を行う方法がある（例えば、特許文献１参照）。
本構成は、図５に示すように、汚染土壌や地下水をオゾン接触反応槽１２に導入口１より流入させ、オゾン接触反応槽１２にオゾン発生器７から発生するオゾンガスを直接吹き込み、接触させることで処理が行なわれた処理水を排水口５より排出し、除去対象物質である揮発性有機塩素化合物等と反応後のオゾンガスが、活性炭や金属触媒を用いた排オゾン処理装置１１を通して系外に排出される。
第２は、汚染土壌や地下水を、熱処理あるいは曝気処理などを行うことで、揮発性である有機塩素化合物等を気相中に分離し、分離後の有機ハロゲン化合物をオゾンガスと接触させて分解除去を行う方法である（例えば、特許文献１参照）。
【０００４】
構成例としては、図６に示すように、汚染土壌や地下水を有機物分解装置２に導入口１より流入させ、有機物分解装置２内で曝気装置３による曝気処理により揮発性の有機塩素化合物を気相中に分離し、分離後の処理水は排水口５より排出され、気相中の有機塩素化合物は、オゾン接触反応槽１２に送られてオゾン処理される。
また、汚染成分とオゾンとを吸着できる高シリカ吸着剤を充填した吸着反応塔を用い、対象ガスを流して吸着剤表面に汚染成分を吸着濃縮させ、次いでオゾンガスを流して、酸化分解する方法がある（例えば、特許文献２参照）。
【０００５】
【特許文献１】
特開２０００−５５６２号公報（第３頁、第２−３図）
【特許文献２】
特開２０００−５５６３号公報（第２−５頁、第２−３図）
【０００６】
【発明が解決しようとする課題】
このように、従来におけるオゾンガスを被処理対象に直接吹き込み接触させる方法、あるいは被処理対象物質を気相中に分離した後にオゾンと接触させて分解除去を行う方法を用いた揮発性有機塩素化合物の処理、さらには揮発性有機化合物を吸着剤に吸着させた後に、オゾンによる酸化分解処理を行なう、従来の吸着工程と酸化工程とから構成される特許文献２に記載の方法は、いずれもオゾン利用効率を高めるための手段が開示されておらず、次の課題を有する。
先ず、最大濃度負荷を基準としたオゾン発生量により設計されるため、オゾン発生器が大型化し、設備コストの増大を招くという問題があった。
【０００７】
また、処理により土壌や地下水の浄化が進み、除去対象物質の濃度負荷が低下した場合には、必要なオゾン量が下がることから、装置が過大仕様となることで、効率的な運転が困難となり、運転コストの増加を招いていた。
この発明の目的は、上記課題を解決し、更には除去対象物質の濃度負荷変動が大きい場合においても、設備コストを抑えながら、オゾンの利用効率を高めることが可能な処理装置を提供することである。
【０００８】
【課題を解決するための手段】
上記課題を解決するために、オゾンによる揮発性有機化合物処理方法において、において、
被処理液から揮発性有機化合物を分離し、分離した前記揮発性有機化合物を濃縮する有機物濃縮工程と、オゾンガスを濃縮するオゾン濃縮工程とを有し、前記有機物濃縮工程と前記オゾン濃縮工程とを別々に実施し、前記有機物濃縮工程により濃縮された前記揮発性有機化合物を、前記オゾン濃縮工程で濃縮された濃縮オゾンに接触させることにする。
【０００９】
この際に、前記有機物濃縮工程と前記オゾン濃縮工程とは、冷却操作によるものであり、濃縮された前記揮発性有機化合物を加温操作によって脱離させ、前記濃縮オゾンに接触させることにする。
さらに、前記有機物濃縮工程で濃縮した前記揮発性有機化合物は、前記脱離後に前記オゾン濃縮工程へ注入し、前記濃縮オゾンと接触させることにする。
また、前記濃縮オゾンを、前記オゾン濃縮工程から脱離し、前記有機物濃縮工程へ注入し、濃縮した前記揮発性有機化合物と接触させることにする。
また、オゾンによる揮発性有機化合物処理装置において、
被処理液から揮発性有機化合物を分離する有機物分離装置と、前記揮発性有機化合物を濃縮する有機物濃縮装置と、オゾンガスを濃縮するオゾン濃縮装置とを有し、
前記有機物分離装置で分離した前記揮発性有機化合物を前記有機物濃縮装置に導入する第一の導入手段と、前記第一の導入手段に対して前記有機物濃縮装置を介して排出する第一の排出手段と、前記オゾン濃縮装置へのオゾン注入手段と、前記オゾン濃縮装置からの排出をする第二の排出手段とを有して、
前記第一の排出手段からの排出物と前記オゾンガスとを接触する手段からなることにする。
【００１０】
この際に、前記有機物濃縮装置は、前記揮発性有機化合物の吸着と脱離とを行なう脱着手段を有し、前記オゾン濃縮装置は、前記オゾンガスを吸着する吸着手段を有し、
前記脱着手段と前記吸着手段における吸着には冷却手段を設け、前記脱着手段における脱離には加温手段を設けることにする。
さらに、前記第一の排出手段に第一の切換弁からなる第一の分岐手段を設け、前記第一の分岐手段の一方には第三の排出手段を設け、前記第一の分岐手段の他方を前記オゾン濃縮装置の前記オゾン注入手段と同一側に導入部を設けて前記導入部に接続することにし、
前記有機物濃縮装置は、活性炭、ゼオライトおよびシリカゲルのうち少なくともいずれか一方を充填し、
前記オゾン濃縮装置は、ゼオライトおよびシリカゲルのうち少なくともいずれか一方を充填することにする。
【００１１】
また、前記第二の排出手段に第二の切換弁からなる第二の分岐手段を設け、前記第一の排出手段に第三の切換弁からなる第三の分岐手段を設け、前記第二の分岐手段の一方は前記第二の排出手段であって、前記第二の分岐手段の他方を前記第三の分岐手段の一方に接続し、前記第三の分岐手段の他方は前記有機物分離装置と前記第一の導入手段との間に位置することとし、
前記有機物濃縮装置および前記オゾン濃縮装置は、ゼオライトおよびシリカゲルのうち少なくともいずれか一方を充填することにする。
このように本発明による揮発性有機化合物処理装置によれば、除去対象物質濃度の負荷変動に対応し、効率的な揮発性有機化合物の分解除去を行うことができると同時に、オゾン利用効率を高めることが可能である。
【００１２】
【発明の実施の形態】
以下、本発明を実施例に基づき説明する。図１は、本発明の実施例に係る揮発性有機化合物処理装置である。本実施例において、例えば揮発性有機化合物を含有した被処理水を処理する場合には、被処理水が導入口１を経由して、有機物分離装置２に導入され、有機物分離装置２において、曝気装置３から導入された気体を被処理水中に散気することで、揮発性有機化合物を分離し、分離した揮発性有機化合物は、活性炭やゼオライト、シリカゲル等の吸着能力を有する担体が充填された有機物濃縮装置４に送られる。この時、揮発性有機化合物が分離除去された処理水は、排水口５から排出され、また、有機物濃縮装置４を通過して吸着処理された後の清浄なガスは、切り替え弁Ｖ１を経由して、系外に排出される。この時、切り替え弁Ｖ１からＶ３への経路は、閉じられている。有機物濃縮装置４には、脱着装置６が備えられ、揮発性有機化合物が吸着され続けている濃縮時には、有機物濃縮装置４を常温以下に冷却することで、吸着効率を高めることができる。
【００１３】
一方、揮発性有機化合物の分離と吸着処理に平行して、オゾン発生器７から生成されたオゾンガスを、切り替え弁Ｖ３と介して、ゼオライトやシリカゲル等の吸着能力を有する担体が充填されたオゾン濃縮装置８に送ることで、オゾンを吸収し続けて濃縮を行う。このオゾン吸着工程においては、切り替え弁Ｖ２によりオゾン循環経路９側に開放することで、未吸収のオゾンガス再度オゾン濃縮装置８に供給でき、余剰オゾンが発生しないように運転を行うことができる。オゾン濃縮装置８は、オゾンの吸収効率を高めるために、脱着装置１０が具備されており、オゾン吸着時には冷却をする。冷却温度は、ゼロ℃程度まで下げることが好ましく、さらに好ましくは、−２０〜−５０℃とすることで吸着したオゾンの自己分解を抑制することが可能である。
【００１４】
有機物濃縮装置４とオゾン濃縮装置８は、上記の状態で一定時間運転が行なわれた後、オゾンの供給を停止し、切り替え弁Ｖ１および切り替え弁Ｖ３を切り替え操作することで、切り替え弁Ｖ１とＶ３間の経路を導通させると共に切り替え弁Ｖ１から系外に排出する経路を遮断する。
次いで、有機物濃縮装置４から、濃縮吸着されている揮発性有機化合物を脱離させるために、脱着装置６により有機物濃縮装置４を加温する。有機物濃縮装置４から脱離した揮発性有機化合物は、切り替え弁Ｖ１と切り替え弁Ｖ３との経路を通って、オゾン濃縮装置８に導入され、オゾン濃縮装置８に濃縮されているオゾンと接触する。この時、ゼオライト等に吸着された高濃度オゾンを、効率良く脱離させて揮発性有機化合物と反応性を高めるためには、脱着装置１０を加温することが好ましい。有機物濃縮装置４から脱離された揮発性有機化合物は、オゾン濃縮装置８内の高濃度オゾンと反応することで、きわめて効率的に分解がなされ、処理後のガスを系外に排出するように、切り替え弁Ｖ２は大気側に開放する。
【００１５】
このように図１記載の方式を用いることで、揮発性有機化合物はきわめて高濃度のオゾンガスと接触するため、効率的な分解を行うことができる。また、除去対象物質の濃度変動が大きい場合でも、運転サイクルを変更、あるいは、有機物濃縮装置４を複数本設けることで、負荷に応じた運転が可能となる。さらに、本方式では一定時間かけて必要となるオゾンガスを生成、貯留する方式であるので、オゾン発生器の容量を縮小できるといったメリットが挙げられ、設備コスト、運転コストの削減が可能である。
図２は、本発明の実施例に係る揮発性有機化合物の連続処理装置である。図２においては、有機物濃縮装置４とオゾン濃縮装置８を複数本備えることで、連続処理運転を可能としている。すなわち、有機物濃縮装置４−１と４−２とにより、吸着工程と脱離工程とを交互に行い、それに応じて、オゾン濃縮装置８−１と８−２とにより、オゾンガスの吸着濃縮する工程と、揮発性有機化合物との反応処理とを交互に行うように動作させるものである。図１で示した反応工程を、連続的に実施することが可能となる。
【００１６】
図３は本発明の別の実施例に係る揮発性有機化合物処理装置である。図３に示した揮発性有機化合物処理装置と図１との相違点は、図１の実施例がオゾン濃縮装置８の内部で、揮発性有機化合物をオゾンと接触させて処理していたことに対し、図３に示す実施例では、濃縮された高濃度のオゾンを有機物濃縮装置４に送ることで、揮発性有機化合物が吸着濃縮された有機物濃縮装置４内での反応処理する構成を示す実施例である。
図３の構成においては、有機物濃縮装置４内に充填されている揮発性有機化合物の吸着能力を有する担体としては、ゼオライトやシリカゲル等を利用することができるが、図１の実施例の場合とは異なり、活性炭については、高濃度オゾンと接触すると燃焼する可能性があるため、使用は避けたほうが良い。
【００１７】
本実施例では、有機物濃縮装置４における揮発性有機化合物の吸着濃縮工程では、有機物分離装置２で分離された揮発性有機化合物は、切り替え弁Ｖ４を経由して有機物濃縮装置４に送られ、揮発性有機化合物は有機物濃縮装置４内に吸着され吸着処理後の清浄なガスは排出口４ｂから系外に排出される構成としている。また、オゾンガス吸着濃縮工程において、オゾン濃縮装置８に接続されている切り替え弁Ｖ２０は、オゾン循環経路９へと、切り替え弁Ｖ１への経路とに切り替えられるように配置されている。上記内容以外での揮発性有機化合物の吸着濃縮工程や、オゾンガス吸着濃縮工程については、図１で説明した通りであるので、説明は省略する。
【００１８】
有機物濃縮装置４とオゾン濃縮装置８は、上記の状態で一定時間運転が行なわれた後、オゾンの供給を停止し、切り替え弁Ｖ４および切り替え弁Ｖ２０を切り替え操作することで、切り替え弁Ｖ４とＶ２０間の経路を介して有機物濃縮装置４へ通じる経路を開き、有機物分離装置２への経路は遮断する。
次いで、オゾン濃縮装置８に濃縮されている高濃度オゾンは、脱着装置１０を冷却から加温に切り替えることにより、オゾン濃縮装置８内から脱離し、切り替え弁Ｖ２０からＶ４への経路を通り、有機物濃縮装置４内に送られることで、有機物濃縮装置４内に蓄積された揮発性有機化合物と反応し、きわめて効率的に分解がなされる。そして、オゾンによる揮発性有機化合物分解後の正常なガスは排出口４ｂから系外に排出される。また、オゾンと揮発性有機化合物とが接触して反応する工程では、脱着装置６により有機物濃縮装置４を加温し、オゾンと有機物との反応性を高めることが好ましい。
【００１９】
図４は本発明の別の実施例に係る揮発性有機化合物処理装置である。本実施例では、揮発性有機化合物とオゾンを接触させ分解する工程において、脱着装置１０によりオゾン濃縮装置８を加温すると共に、水蒸気供給装置１３を備え、加湿をすることで、オゾンの分解を促進してＯＨラジカル生成効率を高め、オゾンと有機物の反応性を高める機能を有しているものである。
図４の実施例においては、図１の揮発性有機化合物処理装置に対する応用として示したが、特にこの構成に限定されるものではなく、図２や図３にも適用可能なことは、言うまでもない。
【００２０】
一般に、オゾンガスを用いたときの効率は、オゾン利用効率として（１）式で定義をされる。

（１）式において、注入したオゾン量−排オゾン量は、オゾンが除去対象物質と反応して消費された量であり、オゾン消費量と呼ばれる。この、オゾン消費量は除去対象物質との反応量に依存するので、除去対象物質に対して、過小量のオゾンを供給した場合には、オゾンは速やかに消費される反面、十分な除去効率は得られず、逆に除去対象物質に対して、過大なオゾンを供給した場合には、除去対象物質は十分に分解されるが、オゾン利用効率は低下することになる。従って、これらのオゾン利用による水質浄化装置、気体浄化装置においては、十分な除去対象物質除去率を維持し、かつオゾン利用効率を高めるような運転制御を行うことが重要である。
【００２１】
【発明の効果】
この発明では、被処理対象物から、揮発性有機化合物を分離して、吸着させ濃縮する工程と、オゾンガスを吸着させ濃縮する工程とを有し、揮発性有機化合物とオゾンのそれぞれの濃縮後に、濃縮された揮発性有機化合物と、濃縮されたオゾンとを接触させることで、オゾン発生設備容量を縮小化でき、オゾン利用効率を高めることで、設備費の削減、および運転コストの低減を行うことができる。
【図面の簡単な説明】
【図１】本発明の実施例に係る揮発性有機化合物処理装置構成図
【図２】本発明の実施例に係る揮発性有機化合物の連続処理装置構成図
【図３】本発明の別の実施例に係る揮発性有機化合物処理装置構成図
【図４】本発明の別の実施例に係る揮発性有機化合物処理装置構成図
【図５】従来のオゾンガス直接吹き込み方式による揮発性有機化合物処理装置構成図
【図６】従来の揮発性有機塩素化合物気相中分離方式による処理装置構成図
【符号の説明】
１：導入口
２：有機物分離装置
３：曝気装置
４：有機物濃縮装置
５：排水口
６：脱着装置
７：オゾン発生器
８：オゾン濃縮装置
１０：脱着装置
１３：水蒸気供給装置[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an oxidative decomposition treatment of a volatile organic compound using ozone.
[0002]
[Prior art]
In recent years, the pollution of volatile organic chlorine compounds such as trichloroethylene and tetrachloroethylene in soil and groundwater has become serious, and these volatile organic chlorine compounds are hardly decomposable, so the strong oxidizing power of ozone is used. Purified devices are widely used.
When applying ozone treatment in the treatment of, for example, trichloroethylene or tetrachlorethylene in soil or groundwater, the following two treatment methods are roughly used.
[0003]
First, there is a method in which ozone gas is directly blown into and contaminated with contaminated soil or groundwater to perform treatment (for example, see Patent Document 1).
In this configuration, as shown in FIG. 5, contaminated soil or groundwater flows into the ozone contact reaction tank 12 from the inlet 1, and the ozone gas generated from the ozone generator 7 is directly blown into the ozone contact reaction tank 12 to make contact therewith. The treated water treated in the above is discharged from the drain port 5, and the ozone gas after the reaction with the volatile organic chlorine compound or the like to be removed is discharged outside the system through the waste ozone treatment device 11 using activated carbon or a metal catalyst. Is discharged.
The second is that the contaminated soil and groundwater are subjected to heat treatment or aeration treatment to separate volatile organic chlorine compounds and the like into the gas phase, and to separate and separate the separated organic halogen compounds with ozone gas to remove them. (For example, see Patent Document 1).
[0004]
As a configuration example, as shown in FIG. 6, contaminated soil and groundwater flow into the organic matter decomposer 2 from the inlet 1, and volatile organic chlorine compounds are removed from the organic matter decomposer 2 by aeration treatment by the aerator 3. The separated water is separated into phases, and the treated water after separation is discharged from the drain port 5, and the organic chlorine compound in the gas phase is sent to the ozone contact reaction tank 12 for ozone treatment.
In addition, an adsorption reaction tower filled with a high silica adsorbent capable of adsorbing contaminants and ozone is used, and the target gas is flowed to adsorb and concentrate the contaminants on the adsorbent surface, and then ozone gas is flown to perform oxidative decomposition. (For example, see Patent Document 2).
[0005]
[Patent Document 1]
JP 2000-5562 A (Page 3, FIG. 2-3)
[Patent Document 2]
Japanese Patent Application Laid-Open No. 2000-5563 (Page 2-5, FIG. 2-3)
[0006]
[Problems to be solved by the invention]
As described above, a conventional method of directly blowing and contacting ozone gas into a treatment target, or a method of separating a treatment target substance into a gas phase and then contacting with ozone to decompose and remove the volatile organic chlorine compound is used. The method described in Patent Literature 2, which comprises a conventional adsorption step and an oxidation step, in which the treatment and further the volatile organic compound is adsorbed on the adsorbent and then oxidized and decomposed with ozone, all of which use ozone. Means for increasing the efficiency are not disclosed, and have the following problems.
First, since the ozone generator is designed based on the amount of ozone generation based on the maximum concentration load, there is a problem that the ozone generator becomes large and the equipment cost increases.
[0007]
In addition, if the treatment promotes the purification of soil and groundwater, and the concentration load of the substance to be removed decreases, the required amount of ozone decreases. , Leading to an increase in operating costs.
An object of the present invention is to solve the above-mentioned problems, and further to provide a processing apparatus capable of increasing the use efficiency of ozone while suppressing equipment costs even when the concentration load fluctuation of the substance to be removed is large. is there.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, in a method for treating a volatile organic compound with ozone,
Separating the volatile organic compound from the liquid to be treated, comprising an organic substance concentration step of concentrating the separated volatile organic compound, and an ozone concentration step of concentrating ozone gas, wherein the organic substance concentration step and the ozone concentration step It is performed separately, and the volatile organic compound concentrated in the organic matter concentration step is brought into contact with the concentrated ozone concentrated in the ozone concentration step.
[0009]
At this time, the organic matter concentration step and the ozone concentration step are performed by a cooling operation, and the concentrated volatile organic compound is desorbed by a heating operation and brought into contact with the concentrated ozone.
Further, the volatile organic compound concentrated in the organic matter concentration step is injected into the ozone concentration step after the desorption, and is brought into contact with the concentrated ozone.
Further, the concentrated ozone is desorbed from the ozone concentration step, injected into the organic matter concentration step, and brought into contact with the concentrated volatile organic compound.
In addition, in a volatile organic compound processing apparatus using ozone,
An organic matter separation device that separates a volatile organic compound from a liquid to be treated, an organic matter concentration device that concentrates the volatile organic compound, and an ozone concentration device that concentrates ozone gas,
First introduction means for introducing the volatile organic compound separated by the organic matter separation device into the organic matter concentration device, and first discharge means for discharging the first introduction means to the first introduction means via the organic matter concentration device Having ozone injection means to the ozone concentrator, and second discharge means for discharging from the ozone concentrator,
Means for contacting the ozone gas with the effluent from the first discharging means.
[0010]
At this time, the organic substance concentrating apparatus has a desorbing means for performing adsorption and desorption of the volatile organic compound, and the ozone concentrating apparatus has an adsorbing means for adsorbing the ozone gas,
A cooling means is provided for the adsorption by the desorption means and the adsorption means, and a heating means is provided for the desorption by the desorption means.
Further, the first discharge means is provided with a first branch means comprising a first switching valve, one of the first branch means is provided with a third discharge means, and the other of the first branch means is provided with a third discharge means. Is provided on the same side of the ozone concentrator as the ozone injection means and connected to the introduction section,
The organic matter concentrator is filled with at least one of activated carbon, zeolite and silica gel,
The ozone concentrator is filled with at least one of zeolite and silica gel.
[0011]
Further, the second discharging means is provided with a second branching means comprising a second switching valve, the first discharging means is provided with a third branching means comprising a third switching valve, the second discharging means, One of the branching means is the second discharge means, and the other of the second branching means is connected to one of the third branching means, and the other of the third branching means is the organic matter separation device. It is located between the first introduction means,
The organic matter concentrator and the ozone concentrator are filled with at least one of zeolite and silica gel.
As described above, according to the volatile organic compound treating apparatus of the present invention, the volatile organic compound can be efficiently decomposed and removed in response to the load fluctuation of the concentration of the substance to be removed, and the ozone utilization efficiency is increased. It is possible.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described based on examples. FIG. 1 shows a volatile organic compound processing apparatus according to an embodiment of the present invention. In the present embodiment, for example, when treating the water to be treated containing a volatile organic compound, the water to be treated is introduced into the organic matter separation device 2 via the inlet 1, and aerated in the organic matter separation device 2. The volatile organic compound is separated by diffusing the gas introduced from the device 3 into the water to be treated, and the separated volatile organic compound is filled with a carrier having an adsorption ability such as activated carbon, zeolite, or silica gel. It is sent to the organic matter concentration device 4. At this time, the treated water from which the volatile organic compounds have been separated and removed is discharged from the drain port 5, and the clean gas that has passed through the organic matter concentrator 4 and has been subjected to the adsorption treatment passes through the switching valve V1. And is discharged out of the system. At this time, the path from the switching valve V1 to V3 is closed. The organic substance concentrating apparatus 4 is provided with a desorption apparatus 6, and during the concentration in which the volatile organic compound is continuously adsorbed, the adsorption efficiency can be increased by cooling the organic substance concentrating apparatus 4 to room temperature or lower.
[0013]
On the other hand, in parallel with the separation and adsorption treatment of the volatile organic compounds, the ozone gas generated from the ozone generator 7 is passed through the switching valve V3 to ozone concentration filled with a carrier having adsorption capacity such as zeolite or silica gel. By sending it to the device 8, the ozone is continuously absorbed and concentrated. In this ozone adsorption step, by opening the ozone circulation path 9 side by the switching valve V2, the unabsorbed ozone gas can be supplied again to the ozone concentrator 8, and the operation can be performed so that excess ozone is not generated. The ozone concentrating device 8 is provided with a desorbing device 10 in order to increase the absorption efficiency of ozone, and cools when ozone is adsorbed. The cooling temperature is preferably lowered to about 0 ° C., and more preferably, is set to −20 to −50 ° C., whereby the self-decomposition of the adsorbed ozone can be suppressed.
[0014]
After the organic substance concentrating device 4 and the ozone concentrating device 8 are operated for a certain period of time in the above-described state, the supply of ozone is stopped, and the switching valves V1 and V3 are switched by switching the switching valves V1 and V3. Between the switching valve V1 and the outside of the system.
Next, the organic matter concentrating device 4 is heated by the desorbing device 6 in order to desorb the volatile organic compound concentrated and adsorbed from the organic matter concentrating device 4. The volatile organic compound desorbed from the organic substance concentrating device 4 is introduced into the ozone concentrating device 8 through a path between the switching valve V1 and the switching valve V3, and comes into contact with the ozone concentrated in the ozone concentrating device 8. At this time, it is preferable to heat the desorption device 10 in order to efficiently desorb the high-concentration ozone adsorbed on the zeolite or the like and increase the reactivity with the volatile organic compound. Volatile organic compounds from the organic concentrator 4 is desorbed, by reacting with high concentrations of ozone in the ozone concentrating apparatus 8, an extremely efficient decomposition is made, so as to exhaust gas after treatment to the outside of the system The switching valve V2 opens to the atmosphere.
[0015]
In this manner, by using the method shown in FIG. 1, the volatile organic compound comes into contact with an extremely high concentration of ozone gas, so that efficient decomposition can be performed. Further, even when the concentration fluctuation of the substance to be removed is large, the operation according to the load can be performed by changing the operation cycle or providing a plurality of the organic substance concentration devices 4. Furthermore, since this method is a method of generating and storing the required ozone gas over a certain period of time, there is an advantage that the capacity of the ozone generator can be reduced, and equipment costs and operation costs can be reduced.
FIG. 2 is an apparatus for continuously treating volatile organic compounds according to an embodiment of the present invention. In FIG. 2, continuous processing operation is enabled by providing a plurality of the organic matter concentrating devices 4 and the ozone concentrating devices 8. That is, the adsorption step and the desorption step are alternately performed by the organic substance concentrators 4-1 and 4-2, and the ozone gas is condensed and absorbed by the ozone concentrators 8-1 and 8-2. And a reaction treatment with a volatile organic compound. The reaction steps shown in FIG. 1 can be performed continuously.
[0016]
FIG. 3 shows a volatile organic compound treating apparatus according to another embodiment of the present invention. The difference between the volatile organic compound treatment apparatus shown in FIG. 3 and FIG. 1 is that the embodiment of FIG. 1 treats the volatile organic compound with ozone in the interior of the ozone concentrator 8. On the other hand, in the embodiment shown in FIG. 3, the concentrated high-concentration ozone is sent to the organic matter concentrator 4 to perform the reaction treatment in the organic matter concentrator 4 in which the volatile organic compound is adsorbed and concentrated. It is an example.
In the configuration of FIG. 3, zeolite, silica gel, or the like can be used as the carrier that has the ability to adsorb the volatile organic compound filled in the organic substance concentrating device 4. Unlike activated carbon, it is better to avoid using it because it may burn when it comes in contact with high-concentration ozone.
[0017]
In the present embodiment, in the step of adsorbing and concentrating volatile organic compounds in the organic matter concentrating device 4, the volatile organic compounds separated by the organic matter separating device 2 are sent to the organic matter concentrating device 4 via the switching valve V4 and volatilized. The volatile organic compound is adsorbed in the organic matter concentrating device 4, and the clean gas after the adsorption treatment is discharged from the outlet 4b to the outside of the system. Further, in the ozone gas adsorption / concentration step, the switching valve V20 connected to the ozone concentrating device 8 is disposed so as to be switched between the ozone circulation path 9 and the path to the switching valve V1. The step of adsorbing and concentrating volatile organic compounds and the step of adsorbing and concentrating ozone gas other than those described above are the same as those described with reference to FIG.
[0018]
After the organic matter concentrating device 4 and the ozone concentrating device 8 are operated for a certain period of time in the above state, the supply of ozone is stopped, and the switching valves V4 and V20 are switched by operating the switching valves V4 and V20. The path leading to the organic matter concentrating device 4 is opened via the path between them, and the path to the organic matter separating device 2 is shut off.
Next, the high-concentration ozone concentrated in the ozone concentrating device 8 is desorbed from the inside of the ozone concentrating device 8 by switching the desorbing device 10 from cooling to heating, and passes through the path from the switching valve V20 to V4 to remove organic matter. By being sent into the concentration device 4, it reacts with the volatile organic compound accumulated in the organic matter concentration device 4, and is extremely efficiently decomposed. Then, the normal gas after the decomposition of the volatile organic compound by ozone is discharged out of the system from the discharge port 4b. In the step in which the ozone and the volatile organic compound are brought into contact with each other and reacted, it is preferable that the desorption device 6 heats the organic matter concentrating device 4 to increase the reactivity between the ozone and the organic matter.
[0019]
FIG. 4 shows a volatile organic compound treating apparatus according to another embodiment of the present invention. In the present embodiment, in the step of bringing the volatile organic compound into contact with ozone and decomposing the ozone, the desorption device 10 heats the ozone concentrator 8 and includes a steam supply device 13 to humidify the ozone. It has a function of enhancing the efficiency of generating OH radicals and increasing the reactivity between ozone and organic substances.
In the embodiment shown in FIG. 4, the application to the volatile organic compound processing apparatus shown in FIG. 1 is shown. However, it is needless to say that the present invention is not particularly limited to this configuration and can be applied to FIG. 2 and FIG. .
[0020]
Generally, the efficiency when ozone gas is used is defined by the equation (1) as the ozone utilization efficiency.

In the equation (1), the amount of injected ozone minus the amount of exhausted ozone is the amount of ozone consumed by reacting with the substance to be removed, and is referred to as ozone consumption. Since the amount of ozone consumed depends on the amount of reaction with the substance to be removed, if an excessively small amount of ozone is supplied to the substance to be removed, the ozone will be consumed quickly, but sufficient removal efficiency will not be obtained. On the contrary, if excessive ozone is supplied to the substance to be removed, the substance to be removed is sufficiently decomposed, but the ozone utilization efficiency is reduced. Therefore, it is important for such a water purification apparatus and a gas purification apparatus that uses ozone to perform operation control that maintains a sufficient removal rate of a substance to be removed and increases ozone utilization efficiency.
[0021]
【The invention's effect】
In the present invention, a step of separating a volatile organic compound from an object to be treated, adsorbing and concentrating, and a step of adsorbing and concentrating ozone gas, after each concentration of the volatile organic compound and ozone, Contacting the concentrated volatile organic compound with the concentrated ozone can reduce the installed capacity of ozone generation equipment, and reduce the equipment cost and operating cost by increasing the ozone utilization efficiency. Can be.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a volatile organic compound processing apparatus according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a continuous processing apparatus of a volatile organic compound according to an embodiment of the present invention. FIG. 3 is another embodiment of the present invention. FIG. 4 is a configuration diagram of a volatile organic compound processing apparatus according to another example. FIG. 4 is a configuration diagram of a volatile organic compound processing apparatus according to another embodiment of the present invention. FIG. 6: Configuration of a conventional processing apparatus using a volatile organic chlorine compound in the gas phase separation system [Description of symbols]
1: Inlet 2: Organic substance separator 3: Aerator 4: Organic substance concentrator 5: Drain port 6: Desorber 7: Ozone generator 8: Ozone concentrator 10: Desorber 13: Steam supply device

Claims

In the method of treating volatile organic compounds with ozone,
Separating the volatile organic compound from the liquid to be treated, comprising an organic matter concentration step of concentrating the separated volatile organic compound, and an ozone concentration step of concentrating ozone gas, the organic matter concentration step and the ozone concentration step A method for treating a volatile organic compound, wherein the method is performed separately, and the volatile organic compound concentrated in the organic matter concentration step is brought into contact with the concentrated ozone concentrated in the ozone concentration step.

The organic matter concentrating step and the ozone concentrating step are performed by a cooling operation, and the concentrated volatile organic compound is desorbed by a heating operation and brought into contact with the concentrated ozone. 4. The method for treating a volatile organic compound according to item 1.

The volatile organic compound treatment according to claim 1 or 2, wherein the volatile organic compound concentrated in the organic matter concentration step is injected into the ozone concentration step after the desorption, and is brought into contact with the concentrated ozone. Method.

The method according to claim 1, wherein the concentrated ozone is desorbed from the ozone concentration step, injected into the organic matter concentration step, and brought into contact with the concentrated volatile organic compound. 4. .

In a volatile organic compound treatment device using ozone,
An organic matter separation device for separating volatile organic compounds from the liquid to be treated, an organic matter concentration device for concentrating the volatile organic compounds, and an ozone concentration device for concentrating ozone gas,
First introduction means for introducing the volatile organic compound separated by the organic matter separation device into the organic matter concentration device, and first discharge means for discharging the first introduction means through the organic matter concentration device to the first introduction means Having ozone injection means to the ozone concentrator, and second discharge means for discharging from the ozone concentrator,
A volatile organic compound treatment apparatus, comprising: means for contacting the ozone gas with the discharge from the first discharge means.

The organic matter concentrating device includes a desorbing unit that performs adsorption and desorption of the volatile organic compound, and the ozone concentrating device includes an adsorbing unit that adsorbs the ozone gas. Volatile organic compound processing equipment.

The volatile organic compound treating apparatus according to claim 6, wherein a cooling unit is provided for the adsorption by the desorption unit and the adsorption unit, and a heating unit is provided for the desorption by the desorption unit.

The first discharge means is provided with a first branch means comprising a first switching valve, one of the first branch means is provided with a third discharge means, and the other of the first branch means is provided with the other 8. The volatile organic compound treating apparatus according to claim 5, wherein an introduction section is provided on the same side of the ozone concentrating apparatus as the ozone injection means and connected to the introduction section.

The second discharging means is provided with a second branching means comprising a second switching valve, the first discharging means is provided with a third branching means comprising a third switching valve, and the second branching means is provided. One of the second branching means is connected to one of the third branching means, and the other of the third branching means is connected to the organic matter separation device and the second The volatile organic compound treating apparatus according to any one of claims 5 to 7, wherein the apparatus is located between the volatile organic compound and one introducing means.

The volatile organic compound treating apparatus according to any one of claims 5 to 9, wherein the organic matter concentrating apparatus and the ozone concentrating apparatus are filled with at least one of zeolite and silica gel.

The volatile organic compound treating apparatus according to claim 8, wherein the organic matter concentrating apparatus is filled with at least one of activated carbon, zeolite, and silica gel.