JP4586325B2

JP4586325B2 - Detoxification treatment agent for object contaminated with organic halogen compound and detoxification treatment method using the same

Info

Publication number: JP4586325B2
Application number: JP2001297991A
Authority: JP
Inventors: 要樹清水; 俊二阿萬; 康行長井
Original assignee: Tosoh Corp
Current assignee: Tosoh Corp
Priority date: 2001-09-27
Filing date: 2001-09-27
Publication date: 2010-11-24
Anticipated expiration: 2021-09-27
Also published as: JP2003105313A

Description

【０００１】
【発明の属する技術分野】
本発明は、有機ハロゲン化合物で汚染された土壌、産業廃棄物、汚泥、スラッジ、排水、地下水等の被処理物に対する無害化処理剤及びそれを用いた無害化処理方法に関するものである。
【０００２】
【従来の技術】
近年、世界各地でトリクロロエチレン、テトラクロロエチレン、ジクロロメタン、ＰＣＢ（ポリ塩化ビフェニル）及びダイオキシン類等の有機ハロゲン化合物による環境汚染問題が顕在化し大きな問題となっている。
【０００３】
これらの問題に対し、特に有機ハロゲン化合物により汚染された土壌、排水、地下水等に対する無害化用処理剤およびその処理方法が検討され、いくつかの技術報告や特許出願がされている。
【０００４】
１）汚染排水、地下水の場合、真空抽出・吸着法や揚水曝気法等が知られているが、地上への引き上げ装置、さらに引き上げた前記汚染物質の吸着設備、活性炭吸着剤の再生処理や廃棄処理が必要となる。近年、金属系処理剤を混合、散布するだけで汚染物質を分解し無害化する処理法が報告されている。鉄系処理剤により無害化する方法として、例えば特許第２６３６１７１号公報、特公平２−４９１５８号公報、特公平２−４９７９８号公報があるが，汚染排水、地下水のｐＨ調整、水素ガスや還元剤等を供給する脱酸素処理が必要であり、実工法としては困難である。また、先崎ら［工業用水、ＶＯＬ３９１，（１９９１），２９．］によるとトリクロロエチレンで汚染された排水、用水を鉄粉やＮｉまたはＣｕ化学メッキ鉄粉により還元脱塩素処理する技術がある。しかし、これら処理剤自体の経時的性能劣化を抑制するため汚染排水、用水中の溶存酸素を除去することが必要であり、さらに活性を示すニッケルメッキ量の範囲が限られており、再現性が問題として残る。特表平１０−５１３１０３号公報はジクロロメタンをＦｅ−Ｐｄ触媒により分解する技術であるが，比較例として塩化ニッケル溶液でメッキ処理した鉄粉はその分解速度は遅く無害化には長時間を要し、完全に分解できない。
【０００５】
２）汚染土壌、スラッジ、汚泥等の処理法としては掘削土壌または直接土壌中に加熱用電極を挿入し加熱処理する熱脱着法および熱分解法が知られている。この方法では電極近傍は熱分解されるが、その他は揮発性の有機塩素化合物を中心に地上に揮散するだけで根本的な処理法ではない。微生物を経由した還元物質により無害化処理するバイオレメデイエ−ション法があるが、無害化には長時間必要であり、しかも全種類の土壌に対応できず完全な無害化は不可能である。また、汚染土壌に鉄系処理剤を添加した特開平１１−２３５５７７号公報、鉄系を含む卑金属系処理剤と微生物を併用した特開平１１−２５３９２６号公報があるが、短時間に分解されないため、より高性能化が必要である。
【０００６】
【発明が解決しようとする課題】
以上述べたように有機ハロゲン化合物で汚染された被処理物に対する従来の処理法は処理時間が長い、高コスト、処理法が複雑で実用性に乏しいといった課題を抱えている。特に、卑金属系処理剤を添加し、無害化する技術としては、汚染排水、地下水に対するｐＨ調整、脱溶存酸素処理が必要であり、汚染土壌に対しては短時間に分解されないため、高性能化が必要である。
【０００７】
【課題を解決するための手段】
発明者等は、これらの課題を解決するために鋭意検討した結果、本発明を完成するに至ったものであり、有機ハロゲン化合物で汚染された被処理物用無害化処理剤およびそれを用いた処理方法を提供するもので、短期間において汚染有機ハロゲン化合物濃度が法的規制値をクリアすることができる。また、本発明の特徴として難分解性と言われるＣｉｓ−ＤＣＥ（ｃｉｓ−１，２−ジクロロエチレン）、ＭＣ（メチルクロロホルム、１，１，１−トリクロロエタン）、ＰＣＥ（テトラクロロエチレン）をも分解する無害化処理剤を提供するものである。すなわち、本発明は、黒鉛とＦｅ−Ｎｉから成り、黒鉛含有量が２〜１７．３重量％であり、粒径が２００μｍ以下、さらに好ましくは黒鉛相を示す黒鉛面積率がＪＩＳＧ０５５５の顕微鏡試験方法において２〜３０％である被処理物用無害化処理剤である。
【０００８】
以下、本発明についてさらに詳細に説明する。
【０００９】
本発明の無害化処理剤が処理する被処理物は、有機ハロゲン化合物で汚染されたものである。ここに、有機ハロゲン化合物の例としては、ジクロロメタン、四塩化炭素、クロロホルム、１，２−ジクロロエタン、１，１−ジクロロエチレン、Ｃｉｓ−ＤＣＥ（ｃｉｓ−１，２−ジクロロエチレン）、Ｔｒａｎｓ−ＤＣＥ（ｔｒａｎｓ−１，２−ジクロロエチレン）、ＭＣ（メチルクロロホルム、１，１，１−トリクロロエタン）、１，１，２−トリクロロエタン、ＴＣＥ（トリクロロエチレン）、ＰＣＥ（テトラクロロエチレン）、１，３−ジクロロプロペン等の有機塩素系化合物、またはこれらの有機臭素系化合物等が挙げられる。
【００１０】
本発明の無害化処理剤は、黒鉛とＦｅ−Ｎｉから成るものである。ここで述べる黒鉛とは、武井，河嶋［新しい工業材料の科学，炭素と黒鉛製品，金原出版（１９６７），８９］によるとダイヤモンド，無定形炭素とは結晶性等が異なり、結晶構造としては１個の炭素原子が同一平面内で３個の炭素原子と結びつき六角板状偏平な形状をとり，この分子面が３次元的に規則正しく積み重なっている。また、例えば西沢、佐久間［（社）日本金属学会、金属組織写真集、鉄鋼材料編（１９９０）、１６］によると炭化鉄の準安定相であるスフェロイダイト、ソルパイト、トルスタイト、マルテンサイト等のセメンタイトやパ−ライトが熱分解により黒鉛化したものや溶湯状態から冷却時に直接、生成する結晶性炭素を含むとしている。また、発明者らは炭素の内、黒鉛がレ−ザ−ラマン法でラマンシフトとして１５８０ｃｍ^−１に、Ｘ線回折法では２θ＝２６．５゜（１０１面）に他の炭素とは異なる特有のピ−クがあることを確認している。
【００１１】
本発明の無害化処理剤により有機ハロゲン化合物を無害化する場合、１）処理剤中のα−鉄等の卑な部分が酸化反応場として溶解（イオン化）し電子放出、２）処理剤中の主に黒鉛相部分の貴な部分が電子を受け還元反応場として有機ハロゲン化合物を脱ハロゲン分解する。
【００１２】
この酸化還元反応速度を上げるためにはα−鉄などの卑な部分と黒鉛相部分の接触面積を大きくする組織が必要であり、黒鉛量を増加し言い換えれば黒鉛相の形状を問わず黒鉛相の占める面積率が大きく、ミクロ的に分散配列し反応場を増やすことが望ましい。
【００１３】
そのため、本発明の無害化処理剤は、レ−ザ−ラマン法またはＸ線回折法により黒鉛結晶性を示すピ−ク強度比より黒鉛含有量が２〜１７．３重量％であり、残部がＦｅまたはＦｅ−Ｎｉである組織を有する。黒鉛含有量が２重量％未満であると有機ハロゲン化合物を脱塩素分解する場の面積が少なすぎるため分解能は低下する。また、黒鉛含有量が１７．３重量％を超えても分解能は低下する。処理剤のコスト面，分解能から特に２〜１５重量％が望ましい。
【００１４】
さらに、処理剤中の黒鉛面積率としてＪＩＳ−Ｇ０５５５に示す顕微鏡試験方法による測定において２〜３０％であると高分解性を示す。この顕微鏡試験方法は点算法による顕微鏡試験方法であり、顕微鏡の倍率を通常４００倍とし、測定視野数を通常６０とし、顕微鏡接眼鏡に縦、横各々２０本の格子線を有するガラス板を挿入して、被検面をランダムに繰り返し検鏡し、黒鉛相によって占められる格子点中心の数を数えるものである。土壌環境基準項目に該当する有機ハロゲン化合物を生成することなく短時間に分解を終了することができ、処理コストを考慮すると黒鉛面積率は、２〜３０％が好ましく、特に１０〜２０％がより好ましい。
【００１５】
また、本発明の無害化処理剤は、黒鉛の他は残部がＦｅまたはＦｅ−Ｎｉである。特にニッケル含有量の測定はＪＩＳ−Ｇ１２１６のニッケル定量方法に基づき測定し、０．１〜１５重量％、特に０．１〜５重量％であることが望ましい。ニッケル含有量が０．１〜１５重量％であれば、無害化処理剤中の黒鉛化に寄与し、分解能は黒鉛−Ｆｅ系に比べ増加する。また経済的にも有利である。
【００１６】
本発明の無害化処理剤の製造方法例としては、１）黒鉛とＦｅ原料（α−鉄，鋼，鋳鉄，海綿状鉄粉を含む）またはＦｅ−Ｎｉ原料（Ｆｅ原料と純Ｎｉの混合品，鉄ニッケル合金含む）を機械的に混合・合金化するメカニカルアロイ法。２）１）の原料をホットプレスやＨＩＰ等で板状，柱状に整形し、必要に応じては粉末化する方法。３）所定の炭素，Ｆｅ，およびＮｉ量からなる溶湯より黒鉛含有板，棒等を鋳こみ、必要に応じて熱処理する方法、例えば、１１５０℃以上に加熱した該溶融金属を所定の冷却速度を保ち、所定の形状に鋳込む。さらに第一段焼戻として９３０℃〜９５０℃、２０〜２５分間、第二段焼戻として６９０℃〜７４０℃、２５〜４０分間を行う。さらに、必要に応じて粉砕処理後、篩処理を行う方法。４）３）の溶解板等をジョークラッシャー，ジャイレ−トリクラッシャ−等の粗粉砕、必要であればスタンプミル，ボ−ルミル，過流ミルを用いて機械的微粉砕し粉末にする方法。５）所定の炭素，鉄，およびＮｉ量を含有する溶湯から直接黒鉛含有粒末を製造する粒状化法またはアトマイズ法であり、必要に応じて焼鈍処理を行う。６）黒鉛粒を添加した金属塩溶液から電解採取し、電極から剥離、粉砕する方法等があるが、これらの製法に限定されるものではない。
【００１７】
本発明における処理剤の形状は特に限定するものではなく、汚染地下水や汚泥水には板状、棒状、網目状、粉末状、汚染土壌には粉末状が好ましく球形状、樹枝状、片状、針状、角状、積層状、海綿状、板状等が含まれる。また粉末状の場合には、比表面積は０．０５ｍ^２／ｇ以上、好ましくは０．２〜１０ｍ^２／ｇ、また２００μｍのふるいを通過する粒径を用いる。特に実施例のうち比表面積が０．５ｍ^２／ｇ以上、粒径７５μｍ以下の分解剤は難分解性と言われているＣｉｓ−ＤＣＥ、ＭＣ、ＰＣＥをも、短時間に分解することができるのでより好ましい。
【００１８】
本発明の無害化処理剤は、以上に説明したような黒鉛を含むものであるが、その効果を損なわない程度で添加剤を含んでいてもよい。添加剤としては特に限定するものではなく、例えば、酸化防止剤、反応促進剤、分散剤、ｐＨ調整剤、脱酸素処理剤等があげられる。酸化防止剤としては亜硫酸ナトリウム、硫酸第一鉄、硫化鉄、アスコルビン酸等、反応促進剤としては塩化ナトリウム、硫酸ナトリウム等、分散剤としては、活性炭素、アルミナ、ゼオライト、シリカゲル、シリカ−アルミナ等があげられる。
【００１９】
また、本発明の無害化処理剤は還元的脱ハロゲンにより無害化するものであるが、従来技術であるフェントン酸化法の触媒剤としても使用することができる。
【００２０】
無害化処理剤の添加、混合方法例としては、１）掘削した土壌をパイル状に積み上げ本発明の無害化処理剤を添加しドラム型スクラバ−、改質ミキサ−、ニ−ダ−等による連続均一混合処理やバックホウ等による回分混合処理後埋め戻す方法、またはパイル状に積み上げ養生する方法。２）汚染土壌中に縦または横井戸を堀り、無害化処理剤を高圧空気または高圧水で注入する原位置処理法。３）無害化処理剤、分散剤、反応促進剤等をスラリ−状にして土壌に注入する方法。４）揚水した汚染地下水等に対しては無害化処理剤を充填した処理塔を通す連続処理法。５）処理井戸を掘削する際に発生した砂利、石、岩等をジョ−クラッシャ−等で粉砕し、無害化処理剤と混合し井戸に埋め戻す透過壁法。６）汚染地下水位置より低い部分に無害化処理剤層を設けた浄化ピット法等を用いることができる。
【００２１】
無害化処理剤の添加量は、被処理物中の有機ハロゲン化合物と接触確率を高くして分解速度の増加、また経済性を考慮すると、粉末状では湿体土壌や地下水等の被処理物に対して０．１〜１０重量％であることが好ましい。
【００２２】
【実施例】
次に、本発明を実施例にさらに具体的に説明するが、本発明はこれらによって限定されるものではない。
【００２３】
実施例１〜５、参考例１〜４、および比較例１〜８
ＴＣＥ含有汚染溶液に対する本発明の無害化処理剤の試験を行った。１２５ｍｌバイアル瓶に１００ｐｐｍのＴＣＥ水溶液、メタノ−ルに溶解した内標ベンゼン、そして本発明の処理剤を素早く入れて密封した。反応条件として３０℃、２００ｒｐｍ浸とうを維持した。尚、この水溶液は脱溶存酸素処理、ｐＨ調整は行っていない。
【００２４】
用いた処理剤はレ−ザ−ラマン法によるピ−ク強度比より黒鉛含有量を測定した。また、ＪＩＳＧ０５５５の顕微鏡試験方法による測定で黒鉛面積率を求めた。なお、比表面積は０．２〜１．２ｍ²／ｇ、７５μｍのふるいを通過した粉末を用いた。
【００２５】
参考例１〜４はＦｅ−黒鉛系粉末（黒鉛量２．７〜１７．３重量％、黒鉛面積率１４〜２３％）、実施例１〜５はＦｅ−Ｎｉ−黒鉛系粉末（黒鉛量３．３〜１７．１重量％、黒鉛面積率１３〜２９％、Ｎｉ含有量０．９１〜１２．２重量％）である。
【００２６】
比較例２，６は黒鉛含有量が１重量％未満の処理剤であり、比較例３〜５、７〜８は黒鉛含有量が２０重量％を超える処理剤であり、そのうち比較例６〜８はＮｉを含有する処理剤（Ｎｉ量１．８３〜１２．３重量％）を用いた。
【００２７】
比較例１、参考例２〜３、実施例１〜４、比較例２，６は溶解金属を棒状に鋳込み後、粉末化したもの、その他の処理剤はメカニカルアロイ法による粉末である。各処理剤の添加量は全て１ｇ（対水溶液１重量％）である。
【００２８】
ＴＣＥ濃度の分析方法としては、ＪＩＳＫ０１２５（用水、排水中の揮発性有機化合物試験方法）に基づいたヘッドスペース法を用い、ＴＣＥ濃度を経時的に定量分析した。これらの測定結果を表１、図１（Ｆｅ−黒鉛系）および表２、図２（Ｆｅ−Ｎｉ−黒鉛系）に示す。
【００２９】
【表１】

【表２】

参考例１〜４のＦｅ−黒鉛系において７〜１０日後、実施例１〜５のＦｅ−Ｎｉ−黒鉛系においては２〜１３日後のＴＣＥ濃度は土壌環境基準０．０３ｐｐｍ未満となった。分解生成物はエチレンが主成分であるが、その他の環境基準項目の有機塩素系化合物は生成していないことを確認した。
【００３０】
これに対し、比較例２，６は黒鉛含有量が１重量％未満の処理剤であるが、２０日後もＴＣＥ濃度が０．０３ｐｐｍ未満にならなかった。比較例３〜５および比較例７，８は黒鉛含有量が２０重量％を超えた処理剤であり、２０日後ＴＣＥ濃度は０．０３ｐｐｍ未満にならなかった。
【００３１】
図１は処理剤中の黒鉛含有量とＴＣＥ溶液濃度の関係を示すが、黒鉛含有量が１〜２０重量％間でＴＣＥ濃度が０．０３ｐｐｍ未満となることが分かる。図２は分解時間とＴＣＥ溶液濃度の関係を示し、主な分解挙動として参考例２，４，実施例１，５、比較例２，４を示す。実施例は短時間にＴＣＥが分解し環境基準値０．０３ｐｐｍ未満になっていることが分かる。
【００３２】
従って、実施例１〜５で用いた無害化処理剤を用いればＴＣＥ汚染水溶液を分解する能力は顕著であり、短期間に法的規制値をクリアすることができることが分かった。
【００３３】
参考例５〜８、実施例６〜１０、および比較例９〜１６
揮発性有機ハロゲン化合物を含有する汚染土壌における無害化処理剤の効果を調べた。１２５ｍｌバイアル瓶に１００ｐｐｍのＴＣＥ汚染土壌１０ｇ、純水１００ｍｌ、メタノ−ルに溶解した内標ベンゼン、そして処理剤を素早く入れて密封した。反応条件として３０℃、２００ｒｐｍ浸とうを維持した。この水溶液は脱溶存酸素処理、ｐＨ調整は行っていない。
【００３４】
用いた処理剤の黒鉛含有量、黒鉛面積率の測定方法、また用いた粉末の比表面積、粒径は参考例１〜４、実施例１〜５、比較例１と同様な粉末を用いた。
【００３５】
参考例５〜８はＦｅ−黒鉛系粉末（黒鉛量２．７〜１７．３重量％、黒鉛面積率１４〜２３％）、実施例６〜１０はＦｅ−Ｎｉ−黒鉛系粉末（黒鉛量３．３〜１７．１重量％、黒鉛面積率１３〜２９％、Ｎｉ含有量０．９１〜１２．２重量％）である。
【００３６】
比較例１１，１４は黒鉛含有量が１重量％未満の処理剤であり、比較例１２，１３、１５，１６は黒鉛含有量が２０重量％を超える処理剤であり、そのうち比較例１４〜１６はＮｉを含有する処理剤（Ｎｉ量２．１〜１２．３重量％）を用いた。
【００３７】
比較例９、参考例５〜６、実施例６〜９、比較例１０，１４は溶解金属を棒状に鋳込み後、粉末化したもの、その他な剤はメカニカルアロイ法による粉末である。各処理剤の添加量は全て１ｇ（対泥状１重量％）である。
【００３８】
ＴＣＥ濃度の分析方法としては、ヘッドスペ−ス法を用い、ＴＣＥ濃度を経時的に定量分析した。その測定結果を表３、図３（Ｆｅ−黒鉛系）および表４、図４（Ｆｅ−Ｎｉ−黒鉛系）に示す。
【００３９】
【表３】

【表４】

参考例５〜８のＦｅ−黒鉛系において１１〜１５日後、実施例６〜１０のＦｅ−Ｎｉ−黒鉛系においては４〜２１日後のＴＣＥ濃度は土壌環境基準０．０３ｐｐｍ未満となった。分解生成物はエチレンが主成分であるが、その他の環境基準項目の有機塩素系化合物は生成していないことを確認した。
【００４０】
これに対し、比較例１１，１４は黒鉛含有量が１重量％未満の処理剤であるが、３０日後もＴＣＥ濃度が０．０３ｐｐｍ未満にならなかった。比較例１２，１３および比較例１５，１６は黒鉛含有量が２０重量％を超えた処理剤であり、３０日後ＴＣＥ濃度が０．０３ｐｐｍ未満にならなかった。
【００４１】
図３は処理剤中の黒鉛含有量と土壌中ＴＣＥ濃度の関係を示すが、黒鉛含有量が１〜２０重量％間でＴＣＥ濃度が０．０３ｐｐｍ未満となることが分かる。図４は分解時間と土壌中ＴＣＥ濃度の関係を示し、主な分解挙動として参考例６，８，実施例８，１０、比較例１０，１４を示す。実施例は短時間にＴＣＥが分解し環境基準値０．０３ｐｐｍ未満になっていることが分かる。
【００４２】
従って、実施例６〜１０で用いた無害化処理剤を用いれば土壌、汚泥中に含有するＴＣＥを分解する能力は顕著であり、短期間に法的規制値をクリアすることができることが分かった。
【００４３】
参考例９〜１１、実施例１１〜１４、および比較例１７〜２４
ＰＣＥ含有汚染溶液に対する本発明の無害化処理剤の試験を行った。１２５ｍｌバイアル瓶に１００ｐｐｍのＰＣＥ水溶液、メタノ−ルに溶解した内標ベンゼン、そして本発明処理剤を素早く入れて密封した。反応条件として３０℃、２００ｒｐｍ浸とうを維持した。尚、この水溶液は脱溶存酸素処理、ｐＨ調整は行っていない。
【００４４】
用いた処理剤の黒鉛含有量、黒鉛面積率の測定は参考例１〜４、実施例１〜５、比較例１と同様である。また、用いた処理剤粉末の比表面積は０．２〜１．２ｍ^２／ｇ、７５μｍのふるいを通過した粉末を用いた。
【００４５】
参考例９〜１１はＦｅ−黒鉛系粉末（黒鉛量３．７〜１７．３重量％、黒鉛面積率１３〜２３％）、実施例１１〜１４はＦｅ−Ｎｉ−黒鉛系粉末（黒鉛量３．３〜１７．１重量％、黒鉛面積率１３〜２９％、Ｎｉ含有量０．９１〜１２．２重量％）である。
【００４６】
比較例１８，２２は黒鉛含有量が１重量％未満の処理剤であり、比較例１９〜２１、２３〜２４は黒鉛含有量が２０重量％を超える処理剤であり、そのうち比較例２２〜２４はＮｉを含有する処理剤（Ｎｉ量２．１〜１２．３重量％）を用いた。
【００４７】
比較例１７、参考例９、実施例１１〜１３、比較例１８，２２は溶解金属を棒状に鋳込み後、粉末化したもの、その他の剤はメカニカルアロイ法による粉末である。各処理剤の添加量は全て１ｇ（対水溶液１重量％）である。
【００４８】
ＰＣＥ濃度の分析方法としては、ＪＩＳＫ０１２５（用水、排水中の揮発性有機化合物試験方法）に基づいたヘッドスペ−ス法を用い、ＰＣＥ濃度を経時的に定量分析した。これらの測定結果を表５、図５（Ｆｅ−黒鉛系）および表６、図６（Ｆｅ−Ｎｉ−黒鉛系）に示す。
【００４９】
【表５】

【表６】

参考例９〜１１のＦｅ−黒鉛系において７４〜８１日後、実施例２２〜２５のＦｅ−Ｎｉ−黒鉛系においては１１〜５９日後のＰＣＥ濃度は土壌環境基準０．０１ｐｐｍ未満となった。分解生成物はエチレンが主成分であるが、その他の環境基準項目の有機塩素系化合物は生成していないことを確認した。
【００５０】
これに対し、比較例１８，２２は黒鉛含有量が１重量％未満の処理剤であるが、９０日後もＰＣＥ濃度が０．０１ｐｐｍ未満にならない。比較例１９〜２１および比較例２３，２４は黒鉛含有量が２０重量％を超えた処理剤であり、９０日後ＰＣＥ濃度は０．０１ｐｐｍ未満にならなかった。
【００５１】
図５は処理剤中の黒鉛含有量とＰＣＥ溶液濃度の関係を示すが、黒鉛含有量が１〜２０重量％間でＴＣＥ濃度が０．０１ｐｐｍ未満となることが分かる。図６は分解時間とＰＣＥ溶液濃度の関係を示し、主な分解挙動として比較例１７，参考例１１，実施例１２，１４、比較例１８，２２を示す。実施例は短時間にＰＣＥが分解し環境基準値０．０１ｐｐｍ未満になっていることが分かる。
【００５２】
従って、実施例１１〜１４で用いた無害化処理剤を用いれば難分解性と言われるＰＣＥを含む汚染水溶液を分解する能力は顕著であり、短期間で法的規制値をクリアすることができることが分かった。
【００５３】
参考例１２〜１４、実施例１５〜１８、および比較例２５〜３２
Ｃｉｓ−ＤＣＥ含有汚染溶液に対する本発明の無害化処理剤の試験を行った。１２５ｍｌバイアル瓶に１０ｐｐｍのＣｉｓ−ＤＣＥ水溶液、メタノ−ルに溶解した内標ベンゼン、そして本発明処理剤を素早く入れて密封した。反応条件として３０℃、２００ｒｐｍ浸とうを維持した。尚、この水溶液は脱溶存酸素処理、ｐＨ調整は行っていない。
【００５４】
用いた処理剤の黒鉛含有量、黒鉛面積率の測定は参考例１〜４、実施例１〜５、比較例１と同様である。また、用いた処理剤粉末の比表面積は０．２〜１．２ｍ^２／ｇ、７５μｍのふるいを通過した粉末を用いた。
【００５５】
参考例１２〜１４はＦｅ−黒鉛系粉末（黒鉛量３．７〜１７．３重量％、黒鉛面積率１５〜２３％）、実施例１５〜１８はＦｅ−Ｎｉ−黒鉛系粉末（黒鉛量３．３〜１７．１重量％、黒鉛面積率１３〜２９％、Ｎｉ含有量０．９１〜１２．２重量％）である。
【００５６】
比較例２６，３０は黒鉛含有量が１重量％未満の処理剤であり、比較例２７〜２９、３１，３２は黒鉛含有量が２０重量％を超える処理剤であり、そのうち比較例３０〜３２はＮｉを含有する処理剤（Ｎｉ量２．１〜１２．３重量％）であり、比表面積および粒径は実施例と同程度を用いた。
【００５７】
比較例２５、参考例１２，実施例１５〜１８、比較例２６，３０は溶解金属を棒状に鋳込み後、粉末化したもの、その他の処理剤はメカニカルアロイ法による粉末である。各処理剤の添加量は全て１ｇ（対水溶液１重量％）である。
【００５８】
Ｃｉｓ−ＤＣＥ濃度の分析方法としては、ＪＩＳＫ０１２５（用水、排水中の揮発性有機化合物試験方法）に基づいたヘッドスペ−ス法を用い、Ｃｉｓ−ＤＣＥ濃度を経時的に定量分析した。これらの測定結果を表７、図７（Ｆｅ−黒鉛系）および表８、図８（Ｆｅ−Ｎｉ−黒鉛系）に示す。
【００５９】
【表７】

【表８】

参考例１２〜１４のＦｅ−黒鉛系において１４〜１８日後、実施例２９〜３２のＦｅ−Ｎｉ−黒鉛系においては５〜２２日後のＣｉｓ−ＤＣＥ濃度は土壌環境基準０．０４ｐｐｍ未満となった。分解生成物はエチレンが主成分であるが、その他の環境基準項目の有機塩素系化合物は生成していないことを確認した。
【００６０】
これに対し、比較例２６，３０は黒鉛含有量が１重量％未満の処理剤であるが、４０日後もＣｉｓ−ＤＣＥ濃度が０．０４ｐｐｍ未満にならない。比較例２７〜２９および比較例３１，３２は黒鉛含有量が２０重量％を超えた処理剤であり、４０日後Ｃｉｓ−ＤＣＥ濃度が０．０４ｐｐｍ未満にならなかった。
【００６１】
図７は処理剤中の黒鉛含有量とＣｉｓ−ＤＣＥ溶液濃度の関係を示すが、黒鉛含有量が１〜２０重量％間でＣｉｓ−ＤＣＥ濃度が０．０４ｐｐｍ未満となることが分かった。図８は分解時間とＣｉｓ−ＤＣＥ溶液濃度の関係を示し、主な分解挙動として参考例１２，１４，実施例１６，１８、比較例２６，３０を示す。実施例は短時間にＣｉｓ−ＤＣＥが分解し環境基準値０．０４ｐｐｍ未満になっていることが分かる。
【００６２】
従って、実施例１５〜１８で用いた無害化処理剤を用いれば難分解性と言われるＣｉｓ−ＤＣＥを含む水溶液を分解する能力は顕著であり、短期間に法的規制値をクリアすることができることが分かった。
【００６３】
参考例１５〜１７、実施例１９〜２２、および比較例３３〜４０
ＭＣ（１，１，１−トリクロロエタン）含有汚染溶液に対する本発明の無害化処理剤の試験を行った。１２５ｍｌバイアル瓶に１０ｐｐｍのＭＣ水溶液、メタノ−ルに溶解した内標ベンゼン、そして本発明処理剤を素早く入れて密封した。反応条件として３０℃、２００ｒｐｍ浸とうを維持した。尚、この水溶液は脱溶存酸素処理、ｐＨ調整は行っていない。
【００６４】
用いた処理剤の黒鉛含有量、黒鉛面積率の測定は参考例１〜４、実施例１〜５、比較例１と同様である。また、用いた処理剤粉末の比表面積は０．２〜１．２ｍ^２／ｇ、７５μｍのふるいを通過した粉末を用いた。
【００６５】
参考例１５〜１７はＦｅ−黒鉛系粉末（黒鉛量３．７〜１７．３重量％、黒鉛面積率１５〜２３％）、実施例１９〜２２はＦｅ−Ｎｉ−黒鉛系粉末（黒鉛量３．３〜１７．１重量％、黒鉛面積率１４〜２９％、Ｎｉ含有量０．９１〜１２．２重量％）である。
【００６６】
比較例３４，３９は黒鉛含有量が１重量％未満の処理剤であり、比較例３５〜３７，３９，４０は黒鉛含有量が２０重量％を超える処理剤であり、そのうち比較例３８〜４０はＮｉを含有する処理剤（Ｎｉ量２．１〜１２．３重量％）であり、比表面積および粒径は実施例と同程度を用いた。
【００６７】
比較例３３、参考例１５、実施例１９〜２２、比較例３４，３８は溶解金属を棒状に鋳込み後、粉末化したもの、その他の処理剤はメカニカルアロイ法による粉末である。各処理剤の添加量は全て１ｇ（対水溶液１重量％）である。
【００６８】
ＭＣ濃度の分析方法としては、ＪＩＳＫ０１２５（用水、排水中の揮発性有機化合物試験方法）に基づいたヘッドスペ−ス法を用い、ＭＣ濃度を経時的に定量分析した。これらの測定結果を表９、図９（Ｆｅ−黒鉛系）および表１０、図１０（Ｆｅ−Ｎｉ−黒鉛系）に示す。
【００６９】
【表９】

【表１０】

参考例１５〜１７のＦｅ−黒鉛系において３〜７日後、実施例１９〜２２のＦｅ−Ｎｉ−黒鉛系においては２〜６日後のＭＣ（１，１，１−トリクロロエタン）濃度は土壌環境基準１ｐｐｍ未満となった。分解生成物はエタンが主成分であるが、その他の環境基準項目の有機塩素系化合物は生成していないことを確認した。また傾向としてはＮｉ含有した処理剤の方が高分解能であることが認められた。これに対し、比較例３４，３８は黒鉛含有量が１重量％未満の処理剤であるが、７日後もＭＣ（１，１，１−トリクロロエタン）濃度が１ｐｐｍ未満にならなかった。比較例３６，３７および比較例３９、４０は黒鉛含有量が２０重量％を超えた処理剤であり、７日後ＭＣ（１，１，１−トリクロロエタン）濃度が１ｐｐｍ未満にはならなかった。
【００７０】
図９は処理剤中の黒鉛含有量とＭＣ溶液濃度の関係を示すが、黒鉛含有量が１〜２０重量％間でＭＣ濃度が１ｐｐｍ未満となることが分かった。図１０は分解時間とＭＣ溶液濃度の関係を示し、主な分解挙動として参考例１５，１７，実施例１９，２２、比較例３４，３８を示す。実施例は短時間にＭＣが分解し環境基準値１ｐｐｍ未満になっていることが分かる。
【００７１】
従って、実施例１９〜２２で用いた無害化処理剤を用いれば難分解性と言われるＭＣ（１，１，１−トリクロロエタン）を含む水溶液を分解する能力は顕著であり、短期間に法的規制値をクリアすることができることが分かった。
【００７２】
【発明の効果】
以上の説明から明らかなように、本発明の無害化処理剤と無害化処理法によれば、土壌、汚泥、水溶液中の有機ハロゲン化合物を短時間に分解し、有害な副生物を生成せず無害化処理できる効果を有するものである。
【図面の簡単な説明】
【図１】ＴＣＥ含有水溶液における処理剤中の黒鉛含有量とＴＣＥ濃度の関係を示した図。
【図２】ＴＣＥ含有水溶液におけるＦｅ−黒鉛系処理剤およびＦｅ−Ｎｉ−黒鉛系処理剤のＴＣＥ挙動の経時変化を示した図。
【図３】ＴＣＥ含有汚染土壌における処理剤中の黒鉛含有量とＴＣＥ濃度の関係を示した図。
【図４】ＴＣＥ含有汚染土壌におけるＦｅ−黒鉛系処理剤およびＦｅ−Ｎｉ−黒鉛系処理剤のＴＣＥ挙動の経時変化を示した図。
【図５】ＰＣＥ含有水溶液における処理剤中の黒鉛含有量とＰＣＥ濃度の関係を示した図。
【図６】ＰＣＥ含有水溶液におけるＦｅ−黒鉛系処理剤およびＦｅ−Ｎｉ−黒鉛系処理剤のＰＣＥ挙動の経時変化を示した図。
【図７】Ｃｉｓ−ＤＣＥ含有水溶液における処理剤中の黒鉛含有量とＣｉｓ−ＤＣＥ濃度の関係を示した図。
【図８】Ｃｉｓ−ＤＣＥ含有水溶液におけるＦｅ−黒鉛系処理剤およびＦｅ−Ｎｉ−黒鉛系処理剤のＣｉｓ−ＤＣＥ挙動の経時変化を示した図。
【図９】ＭＣ含有水溶液における処理剤中の黒鉛含有量とＭＣ濃度の関係を示した図。
【図１０】ＭＣ含有水溶液におけるＦｅ−黒鉛系処理剤およびＦｅ−Ｎｉ−黒鉛系処理剤のＭＣ挙動の経時変化示した図。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a detoxifying agent for an object to be treated such as soil, industrial waste, sludge, sludge, waste water, and groundwater contaminated with an organic halogen compound, and a detoxifying treatment method using the same.
[0002]
[Prior art]
In recent years, environmental pollution problems due to organic halogen compounds such as trichlorethylene, tetrachloroethylene, dichloromethane, PCB (polychlorinated biphenyl) and dioxins have become apparent and become a serious problem in various parts of the world.
[0003]
In response to these problems, treatment agents for detoxification of soil, wastewater, groundwater, etc. contaminated with organic halogen compounds and treatment methods thereof have been studied, and several technical reports and patent applications have been filed.
[0004]
1) In the case of contaminated wastewater and groundwater, vacuum extraction / adsorption method, pumped water aeration method, etc. are known, but the lifting device to the ground, the adsorption equipment for the raised pollutant, regeneration treatment and disposal of activated carbon adsorbent Processing is required. In recent years, treatment methods have been reported that decompose and detoxify pollutants simply by mixing and spraying metal-based treatment agents. As a method of detoxifying with an iron-based treatment agent, for example, there are Japanese Patent No. 2636171, Japanese Patent Publication No. 2-49158, and Japanese Patent Publication No. 2-49798, but there are polluted wastewater, pH adjustment of groundwater, hydrogen gas and a reducing agent. It is difficult as an actual construction method to perform deoxygenation treatment for supplying the like. Also, Sakizaki et al. [Industrial water, VOL 391, (1991), 29. ], There is a technology for reducing and dechlorinating waste water and water contaminated with trichlorethylene with iron powder, Ni or Cu chemical plating iron powder. However, it is necessary to remove the dissolved oxygen from contaminated wastewater and irrigation water in order to suppress the deterioration of performance over time of these treatment agents themselves, and the range of nickel plating amount showing activity is limited, and reproducibility is high. It remains as a problem. Japanese National Patent Publication No. 10-513103 is a technique for decomposing dichloromethane using an Fe-Pd catalyst. As a comparative example, iron powder plated with a nickel chloride solution has a slow decomposition rate and requires a long time to be harmless. Cannot be completely disassembled.
[0005]
2) Thermal desorption methods and thermal decomposition methods are known as treatment methods for contaminated soil, sludge, sludge, etc., in which a heating electrode is inserted into excavated soil or directly into the soil. In this method, the vicinity of the electrode is thermally decomposed, but the others are not fundamental treatment methods because they are volatilized on the ground mainly with volatile organochlorine compounds. There is a bioremediation method in which a detoxification treatment is performed with a reducing substance via microorganisms, but the detoxification requires a long time, and it cannot be applied to all types of soils, so complete detoxification is impossible. Moreover, although there exists Unexamined-Japanese-Patent No. 11-235577 which added the iron-type processing agent to contaminated soil, and Unexamined-Japanese-Patent No. 11-253926 which used the base metal type processing agent containing an iron type, and microorganisms, since it does not decompose | disassemble in a short time There is a need for higher performance.
[0006]
[Problems to be solved by the invention]
As described above, conventional processing methods for an object contaminated with an organic halogen compound have problems that the processing time is long, the cost is high, the processing method is complicated, and the practicality is poor. In particular, as a technology for detoxifying by adding a base metal-based treatment agent, it is necessary to adjust the pH of polluted wastewater and groundwater, and to perform de-dissolved oxygen treatment. is required.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to solve these problems, the inventors have completed the present invention, and used a detoxification treatment agent for an object to be treated contaminated with an organic halogen compound and the same. A treatment method is provided, and the concentration of contaminating organic halogen compounds can clear the legal regulation value in a short period of time. Further, detoxification that also decomposes Cis-DCE (cis-1,2-dichloroethylene), MC (methyl chloroform, 1,1,1-trichloroethane), PCE (tetrachloroethylene), which is said to be hardly decomposable as a feature of the present invention. A treatment agent is provided. That is, the present invention ,black It is composed of lead and Fe—Ni, the graphite content is 2 to 17.3% by weight, the particle size is 200 μm or less, more preferably the graphite area ratio indicating the graphite phase is 2 to 30% in the microscope test method of JISG0555. It is a detoxifying agent for a certain object.
[0008]
Hereinafter, the present invention will be described in more detail.
[0009]
An object to be treated to be treated by the detoxifying agent of the present invention is contaminated with an organic halogen compound. Examples of the organic halogen compound include dichloromethane, carbon tetrachloride, chloroform, 1,2-dichloroethane, 1,1-dichloroethylene, Cis-DCE (cis-1,2-dichloroethylene), Trans-DCE (trans- Organochlorine series such as 1,2-dichloroethylene), MC (methyl chloroform, 1,1,1-trichloroethane), 1,1,2-trichloroethane, TCE (trichloroethylene), PCE (tetrachloroethylene), 1,3-dichloropropene Compounds, or these organic bromine-based compounds.
[0010]
The detoxification treatment agent of the present invention is ,black It consists of lead and Fe-Ni. According to Takei and Kawashima [Science of New Industrial Materials, Carbon and Graphite Products, Kanbara Publishing (1967), 89], the graphite described here is different in crystallinity from diamond and amorphous carbon, and the crystal structure is 1 Each carbon atom is connected to three carbon atoms in the same plane to form a flat hexagonal plate shape, and the molecular planes are regularly stacked three-dimensionally. Moreover, according to Nishizawa, Sakuma [Metal Society of Japan, Metallographic Photographs Collection, Steel Materials (1990), 16], cementite such as spheroidite, solpite, torstatite, martensite, etc., which are metastable phases of iron carbide, It is said that the pearlite contains graphitized carbon by pyrolysis or crystalline carbon that is generated directly from the molten state during cooling. In addition, the inventors of the present invention used graphite as a Raman shift by a laser-Raman method in 1580 cm of carbon. ^-1 In addition, in the X-ray diffraction method, it has been confirmed that there is a unique peak different from other carbons at 2θ = 26.5 ° (101 plane).
[0011]
When detoxifying an organic halogen compound with the detoxifying treatment agent of the present invention, 1) a base portion such as α-iron in the treating agent is dissolved (ionized) as an oxidation reaction field to release electrons, and 2) in the treating agent. The noble part of the graphite phase mainly receives electrons and dehalogenates and decomposes the organic halogen compound as a reduction reaction field.
[0012]
In order to increase the oxidation-reduction reaction rate, a structure that increases the contact area between the base portion such as α-iron and the graphite phase portion is required. In other words, the amount of graphite is increased, in other words, regardless of the shape of the graphite phase. It is desirable to increase the reaction field by microscopically dispersing and arranging the area ratio.
[0013]
Therefore, the detoxifying agent of the present invention has a graphite content from the peak strength ratio showing graphite crystallinity by laser Raman method or X-ray diffraction method. 2-17.3 It has a structure in which the weight is% and the balance is Fe or Fe-Ni. Graphite content 2 If it is less than% by weight, the resolution decreases because the area of the field for dechlorinating the organic halogen compound is too small. Also, the graphite content is 17.3 The resolution decreases even if the weight percentage is exceeded. From the viewpoint of cost and resolution of the treatment agent, 2 to 15% by weight is particularly desirable.
[0014]
Furthermore, it shows high decomposability when it is 2 to 30% in the measurement by the microscope test method shown in JIS-G0555 as the graphite area ratio in the treatment agent. This microscopic test method is a microscopic test method based on a point calculation method. The microscope magnification is usually 400 times, the number of measurement fields is usually 60, and a glass plate having 20 grid lines in the vertical and horizontal directions is inserted into the microscope eyepiece. Then, the surface to be tested is repeatedly and randomly examined, and the number of lattice point centers occupied by the graphite phase is counted. Decomposition can be completed in a short time without producing an organic halogen compound corresponding to the soil environment standard item, and considering the treatment cost, the graphite area ratio is preferably 2 to 30%, more preferably 10 to 20%. preferable.
[0015]
Further, the detoxification treatment agent of the present invention has a balance of Fe or Fe—Ni other than graphite. In particular, the nickel content is measured based on the nickel determination method of JIS-G1216, and is preferably 0.1 to 15% by weight, particularly 0.1 to 5% by weight. When the nickel content is 0.1 to 15% by weight, it contributes to graphitization in the detoxifying treatment agent, and the resolution increases as compared with the graphite-Fe system. It is also economically advantageous.
[0016]
Examples of the method for producing the detoxifying agent of the present invention include 1) graphite and Fe raw material (including α-iron, steel, cast iron, sponge iron powder) or Fe-Ni raw material (mixed product of Fe raw material and pure Ni) Mechanical alloy method that mechanically mixes and alloys (including iron-nickel alloy). 2) A method in which the raw material of 1) is shaped into a plate shape or a column shape by a hot press, HIP or the like, and pulverized as necessary. 3) A method in which a graphite-containing plate, rod, or the like is cast from a molten metal composed of a predetermined amount of carbon, Fe, and Ni and heat-treated as necessary, for example, the molten metal heated to 1150 ° C. or higher has a predetermined cooling rate. Keep and cast into a predetermined shape. Further, 930 ° C. to 950 ° C. for 20 to 25 minutes is performed as the first stage tempering, and 690 ° C. to 740 ° C. and 25 to 40 minutes are performed as the second stage tempering. Furthermore, a method of performing sieving after pulverization if necessary. 4) A method in which the melting plate or the like of 3) is coarsely pulverized by a jaw crusher, a gyratory tricrusher or the like, and if necessary, mechanically pulverized using a stamp mill, a ball mill, or a vortex mill to form a powder. 5) A granulation method or an atomization method in which a graphite-containing particle powder is directly produced from a molten metal containing a predetermined amount of carbon, iron, and Ni, and an annealing treatment is performed as necessary. 6) There are methods such as electrolytic extraction from a metal salt solution to which graphite particles have been added, separation from the electrode, and pulverization, but the method is not limited to these methods.
[0017]
The shape of the treatment agent in the present invention is not particularly limited, plate-like, rod-like, mesh-like, powdery for contaminated groundwater and sludge water, preferably powdery for contaminated soil, spherical, dendritic, piece-like, Needle-shaped, square-shaped, laminated, sponge-like, plate-like and the like are included. In the case of powder, the specific surface area is 0.05m. ² / G or more, preferably 0.2 to 10 m ² / G, and use a particle size that passes through a 200 μm sieve. . Especially in the examples, the specific surface area is 0.5 m. ² A decomposition agent having a particle size of not less than / g and a particle size of not more than 75 μm is more preferable because it can also decompose Cis-DCE, MC and PCE, which are said to be hardly decomposable, in a short time.
[0018]
The detoxification treatment agent of the present invention contains graphite as described above, but may contain additives to such an extent that the effect is not impaired. The additive is not particularly limited, and examples thereof include an antioxidant, a reaction accelerator, a dispersant, a pH adjuster, and a deoxygenating agent. Sodium sulfite, ferrous sulfate, iron sulfide, ascorbic acid, etc. as antioxidants, sodium chloride, sodium sulfate, etc. as reaction accelerators, activated carbon, alumina, zeolite, silica gel, silica-alumina, etc. as dispersants Can be given.
[0019]
The detoxification treatment agent of the present invention is detoxified by reductive dehalogenation, but can also be used as a catalyst agent for the conventional Fenton oxidation method.
[0020]
Examples of methods for adding and mixing the detoxifying agent include 1) piled up the excavated soil in a pile and added with the detoxifying agent of the present invention, and continuously using a drum type scrubber, a reforming mixer, a kneader or the like. A method of backfilling after a batch mixing process using a uniform mixing process or a backhoe, or a method of stacking and curing a pile. 2) An in-situ treatment method in which vertical or horizontal wells are dug in contaminated soil and a detoxifying agent is injected with high-pressure air or high-pressure water. 3) A method in which a detoxifying agent, a dispersant, a reaction accelerator and the like are made into a slurry and injected into soil. 4) A continuous treatment method in which the pumped contaminated groundwater is passed through a treatment tower filled with a detoxifying agent. 5) A permeation wall method in which gravel, stones, rocks, etc. generated during excavation of a treatment well are crushed with a jockey crusher, etc., mixed with a detoxifying treatment agent, and buried in the well. 6) A purification pit method or the like in which a detoxification treatment agent layer is provided in a portion lower than the contaminated groundwater position can be used.
[0021]
The addition amount of the detoxifying agent increases the probability of contact with the organic halogen compound in the treatment object, increases the decomposition rate, and in consideration of economy, the powder is applied to the treatment object such as wet soil or groundwater. The content is preferably 0.1 to 10% by weight.
[0022]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited by these.
[0023]
Example 1 5, Reference Examples 1 to 4, And Comparative Examples 1-8
The detoxification treatment agent of the present invention was tested against a TCE-containing contaminated solution. In a 125 ml vial, 100 ppm of TCE aqueous solution, internal standard benzene dissolved in methanol, and the treatment agent of the present invention were quickly put and sealed. The reaction conditions were maintained at 30 ° C. and 200 rpm immersion. This aqueous solution was not subjected to de-dissolved oxygen treatment and pH adjustment.
[0024]
The used processing agent measured the graphite content from the peak strength ratio by a laser Raman method. Moreover, the graphite area ratio was calculated | required by the measurement by the microscope test method of JISG0555. The specific surface area is 0.2-1.2m. ² / G, powder that passed through a 75 μm sieve was used.
[0025]
reference Examples 1-4 are Fe-graphite-based powders (graphite amount: 2.7-17.3% by weight, graphite area ratio: 14-23%), Examples 1 ~ 5 Is Fe-Ni-graphite-based powder (graphite amount 3.3 to 17.1% by weight, graphite area ratio 13 to 29%, Ni content 0.91 to 12.2% by weight).
[0026]
Comparative example 2 , 6 Is a treatment agent with a graphite content of less than 1% by weight, a comparative example 3 ~ 5 7 ~ 8 Is a treatment agent with a graphite content exceeding 20% by weight, of which a comparative example 6 ~ 8 Used a treatment agent containing Ni (Ni amount: 1.83 to 12.3% by weight).
[0027]
Comparative Example 1, reference Examples 2-3 Example 1 ~ 4 In Comparative Examples 2 and 6, the molten metal was cast into a rod shape and then powdered, and the other treatment agents were powders by a mechanical alloy method. The amount of each treatment agent added is 1 g (1% by weight with respect to the aqueous solution).
[0028]
As a method for analyzing the TCE concentration, a headspace method based on JIS K 0125 (test method for volatile organic compounds in water and wastewater) was used, and the TCE concentration was quantitatively analyzed over time. The measurement results are shown in Table 1, FIG. 1 (Fe-graphite system), Table 2, and FIG. 2 (Fe-Ni-graphite system).
[0029]
[Table 1]

[Table 2]

reference Examples after 7-10 days in the Fe-graphite systems of Examples 1-4 1 ~ 5 In the Fe-Ni-graphite system, the TCE concentration after 2 to 13 days was less than 0.03 ppm based on the soil environment. It was confirmed that the decomposition products are mainly composed of ethylene, but no other organic chlorinated compounds of environmental standard were generated.
[0030]
In contrast, the comparative example 2 , 6 Is a treatment agent having a graphite content of less than 1% by weight, but the TCE concentration did not become less than 0.03 ppm even after 20 days. Comparative example 3 ~ 5 And comparative examples 7 , 8 Is a treating agent having a graphite content exceeding 20% by weight, and after 20 days, the TCE concentration did not become less than 0.03 ppm.
[0031]
FIG. 1 shows the relationship between the graphite content in the treating agent and the TCE solution concentration. It can be seen that the TCE concentration is less than 0.03 ppm when the graphite content is between 1 and 20% by weight. Figure 2 shows the relationship between decomposition time and TCE solution concentration. reference Example 2, 4, Example 1 , 5 Comparative Examples 2 and 4 are shown. In the examples, it can be seen that TCE decomposes in a short time and the environmental standard value is less than 0.03 ppm.
[0032]
Therefore, Examples 1-5 It was found that the use of the detoxifying agent used in 1) has a remarkable ability to decompose the TCE-contaminated aqueous solution, and can clear the legal regulation value in a short time.
[0033]
reference Example 5 ~ 8, Examples 6-10, And Comparative Examples 9-16
The effect of detoxifying agent in contaminated soil containing volatile organic halogen compounds was investigated. In a 125 ml vial, 10 g of 100 ppm TCE-contaminated soil, 100 ml of pure water, internal standard benzene dissolved in methanol, and a treating agent were quickly put and sealed. The reaction conditions were maintained at 30 ° C. and 200 rpm immersion. This aqueous solution was not subjected to de-dissolved oxygen treatment and pH adjustment.
[0034]
The graphite content of the treatment agent used, the method for measuring the graphite area ratio, and the specific surface area and particle size of the powder used were reference Example 1 4. Examples 1-5 The same powder as in Comparative Example 1 was used.
[0035]
reference Example 5 ~ 8 Is Fe-graphite-based powder (graphite amount 2.7 to 17.3% by weight, graphite area ratio 14 to 23%), Examples 6 ~ 1 0 Is Fe-Ni-graphite-based powder (graphite amount 3.3 to 17.1% by weight, graphite area ratio 13 to 29%, Ni content 0.91 to 12.2% by weight).
[0036]
Comparative example 11 , 1 4 Is a treating agent having a graphite content of less than 1% by weight. 2 , 1 3 1 5 , 1 6 Is a treating agent having a graphite content exceeding 20% by weight, of which Comparative Example 1 4 ~ 1 6 Used a treatment agent containing Ni (Ni amount: 2.1 to 12.3% by weight).
[0037]
Comparative Example 9, reference Example 5 ~ 6 , Example 6 ~ 9 In Comparative Examples 10 and 14, the molten metal was cast into a rod shape and then powdered, and the other agents were powders by a mechanical alloy method. The amount of each processing agent added is 1 g (1% by weight with respect to mud).
[0038]
As a method for analyzing the TCE concentration, a head space method was used, and the TCE concentration was quantitatively analyzed over time. The measurement results are shown in Table 3, FIG. 3 (Fe-graphite system), Table 4, and FIG. 4 (Fe-Ni-graphite system).
[0039]
[Table 3]

[Table 4]

reference Example 5 ~ 8 Examples after 11-15 days in the Fe-graphite system 6 ~ 1 0 In the Fe-Ni-graphite system, the TCE concentration after 4 to 21 days was less than 0.03 ppm of the soil environment standard. It was confirmed that the decomposition products are mainly composed of ethylene, but no other organic chlorinated compounds of environmental standard were generated.
[0040]
In contrast, the comparative example 11 , 1 4 Is a treating agent with a graphite content of less than 1% by weight, but the TCE concentration did not become less than 0.03 ppm even after 30 days. Comparative Example 1 2 , 1 3 And Comparative Example 1 5 , 1 6 Was a treating agent having a graphite content exceeding 20% by weight, and after 30 days, the TCE concentration did not become less than 0.03 ppm.
[0041]
FIG. 3 shows the relationship between the graphite content in the treatment agent and the TCE concentration in the soil. It can be seen that the TCE concentration is less than 0.03 ppm when the graphite content is between 1 and 20% by weight. Fig. 4 shows the relationship between decomposition time and TCE concentration in soil. reference Example 6 , 8 , Example 8 , 1 0 Comparative Examples 10 and 14 are shown. In the examples, it can be seen that TCE decomposes in a short time and the environmental standard value is less than 0.03 ppm.
[0042]
Therefore, Examples 6-10 It was found that the use of the detoxification treatment agent used in No. 1 has a remarkable ability to decompose TCE contained in soil and sludge, and can clear legal regulation values in a short time.
[0043]
reference Example 9 ~ 11, Examples 11-14, And Comparative Examples 17-24
The detoxification treatment agent of the present invention against a PCE-containing contaminated solution was tested. In a 125 ml vial, 100 ppm of PCE aqueous solution, internal standard benzene dissolved in methanol, and the treating agent of the present invention were quickly put and sealed. The reaction conditions were maintained at 30 ° C. and 200 rpm immersion. This aqueous solution was not subjected to de-dissolved oxygen treatment and pH adjustment.
[0044]
Measurement of graphite content and graphite area ratio of the treatment agent used reference Example 1 4. Examples 1-5 This is the same as Comparative Example 1. Moreover, the specific surface area of the used processing agent powder is 0.2 to 1.2 m. ² / G, powder that passed through a 75 μm sieve was used.
[0045]
reference Example 9 ~ 1 1 is Fe-graphite-based powder (graphite amount 3.7 to 17.3% by weight, graphite area ratio 13 to 23%), Examples 11 ~ 14 Is Fe-Ni-graphite-based powder (graphite amount 3.3 to 17.1% by weight, graphite area ratio 13 to 29%, Ni content 0.91 to 12.2% by weight).
[0046]
Comparative Example 1 8 , 22 Is a treatment agent with a graphite content of less than 1% by weight, a comparative example 19 ~ 21 2 3 ~ 2 4 Is a treatment agent with a graphite content exceeding 20% by weight, of which a comparative example 22 ~ 2 4 Used a treatment agent containing Ni (Ni amount: 2.1 to 12.3% by weight).
[0047]
Comparative Example 17, reference Example 9 , Example 11 ~ 13 In Comparative Examples 18 and 22, the molten metal was cast into a rod shape and then powdered, and the other agents were powders by mechanical alloying. The amount of each treatment agent added is 1 g (1% by weight with respect to the aqueous solution).
[0048]
As a PCE concentration analysis method, a head space method based on JIS K 0125 (test method for volatile organic compounds in water and wastewater) was used, and the PCE concentration was quantitatively analyzed over time. The measurement results are shown in Table 5, FIG. 5 (Fe-graphite system), Table 6, and FIG. 6 (Fe-Ni-graphite system).
[0049]
[Table 5]

[Table 6]

reference Example 9 ~ 1 After 74 to 81 days in the Fe-graphite system of No. 1 and in the Fe-Ni-graphite systems of Examples 22 to 25, the PCE concentration after 11 to 59 days was less than 0.01 ppm of the soil environment standard. It was confirmed that the decomposition products are mainly composed of ethylene, but no other organic chlorinated compounds of environmental standard were generated.
[0050]
In contrast, Comparative Example 1 8 , 22 Is a treating agent having a graphite content of less than 1% by weight, but the PCE concentration does not become less than 0.01 ppm even after 90 days. Comparative Example 1 9 ~ 21 And Comparative Example 2 3 , 2 4 Is a treating agent having a graphite content exceeding 20% by weight, and after 90 days, the PCE concentration did not become less than 0.01 ppm.
[0051]
FIG. 5 shows the relationship between the graphite content in the treatment agent and the PCE solution concentration. It can be seen that the TCE concentration is less than 0.01 ppm when the graphite content is between 1 and 20% by weight. FIG. 6 shows the relationship between the decomposition time and the PCE solution concentration. As the main decomposition behavior, Comparative Example 17, reference Example 1 1, Example 12 , 14 Comparative Examples 18 and 22 are shown. In the example, PCE decomposes in a short time and the environmental standard value is less than 0.01 ppm. Toga I understand.
[0052]
Therefore, Example 1 1 ~ 14 It was found that the use of the detoxification treatment agent used in 1) remarkably has the ability to decompose a contaminated aqueous solution containing PCE, which is said to be hardly decomposable, and can clear legal regulation values in a short period of time.
[0053]
reference Example 12 ~ 14, Examples 15-18 And Comparative Examples 25-32
The detoxification treatment agent of the present invention was tested against a cis-DCE-containing contaminated solution. In a 125 ml vial, 10 ppm of Cis-DCE aqueous solution, internal standard benzene dissolved in methanol, and the treating agent of the present invention were quickly put and sealed. The reaction conditions were maintained at 30 ° C. and 200 rpm immersion. This aqueous solution was not subjected to de-dissolved oxygen treatment and pH adjustment.
[0054]
Measurement of graphite content and graphite area ratio of the treatment agent used reference Example 1 4. Examples 1-5 This is the same as Comparative Example 1. Moreover, the specific surface area of the used processing agent powder is 0.2 to 1.2 m. ² / G, powder that passed through a 75 μm sieve was used.
[0055]
reference Example 12 ~ 14 Is Fe-graphite-based powder (graphite amount 3.7 to 17.3% by weight, graphite area ratio 15 to 23%), Examples 15 ~ 18 Is Fe-Ni-graphite-based powder (graphite amount 3.3 to 17.1% by weight, graphite area ratio 13 to 29%, Ni content 0.91 to 12.2% by weight).
[0056]
Comparative Example 2 6 , 30 Is a treating agent having a graphite content of less than 1% by weight. 7 ~ 2 9 , 31 , 32 Is a treatment agent with a graphite content exceeding 20% by weight, of which a comparative example 30 ~ 32 Is a treatment agent containing Ni (Ni amount: 2.1 to 12.3% by weight), and the specific surface area and particle size were the same as in the examples.
[0057]
Comparative Example 25, reference Example 12 , Example 15 ~ 18 In Comparative Examples 26 and 30, the molten metal was cast into a rod shape and then pulverized, and the other treatment agents were powders by a mechanical alloy method. The amount of each treatment agent added is 1 g (1% by weight with respect to the aqueous solution).
[0058]
As a method for analyzing the Cis-DCE concentration, a head space method based on JIS K 0125 (Test method for volatile organic compounds in water and wastewater) was used, and the Cis-DCE concentration was quantitatively analyzed over time. The measurement results are shown in Table 7, FIG. 7 (Fe-graphite system), Table 8, and FIG. 8 (Fe-Ni-graphite system).
[0059]
[Table 7]

[Table 8]

reference Example 12 ~ 14 After 14 to 18 days in the Fe-graphite system, and in the Fe-Ni-graphite systems of Examples 29 to 32, the Cis-DCE concentration after 5 to 22 days was less than 0.04 ppm of the soil environment standard. It was confirmed that the decomposition products are mainly composed of ethylene, but no other organic chlorinated compounds of environmental standard were generated.
[0060]
In contrast, Comparative Example 2 6 , 30 Is a treatment agent having a graphite content of less than 1% by weight, but the Cis-DCE concentration does not become less than 0.04 ppm even after 40 days. Comparative Example 2 7 ~ 2 9 And comparative examples 31 , 32 Is a treating agent having a graphite content exceeding 20% by weight, and after 40 days, the Cis-DCE concentration did not become less than 0.04 ppm.
[0061]
FIG. 7 shows the relationship between the graphite content in the treatment agent and the Cis-DCE solution concentration. It was found that the Cis-DCE concentration was less than 0.04 ppm when the graphite content was 1 to 20% by weight. Fig. 8 shows the relationship between decomposition time and Cis-DCE solution concentration. reference Example 12 , 14 , Example 16 , 18 Comparative Examples 26 and 30 are shown. In the example, it can be seen that Cis-DCE decomposes in a short time and is less than the environmental standard value of 0.04 ppm.
[0062]
Therefore, Examples 15-18 It was found that the use of the detoxification treatment agent used in 1) has a remarkable ability to decompose an aqueous solution containing Cis-DCE, which is said to be hardly decomposable, and can clear legal regulation values in a short time.
[0063]
reference Example 15 ~ 17, Examples 19-22, And Comparative Examples 33-40
The detoxification treatment agent of the present invention was tested on a contaminated solution containing MC (1,1,1-trichloroethane). In a 125 ml vial, 10 ppm of MC aqueous solution, internal standard benzene dissolved in methanol, and the treating agent of the present invention were quickly put and sealed. The reaction conditions were maintained at 30 ° C. and 200 rpm immersion. This aqueous solution was not subjected to de-dissolved oxygen treatment and pH adjustment.
[0064]
Measurement of graphite content and graphite area ratio of the treatment agent used reference Example 1 4. Examples 1-5 This is the same as Comparative Example 1. Moreover, the specific surface area of the used processing agent powder is 0.2 to 1.2 m. ² / G, powder that passed through a 75 μm sieve was used.
[0065]
reference Example 15 ~ 17 Is Fe-graphite-based powder (graphite amount 3.7 to 17.3% by weight, graphite area ratio 15 to 23%), Examples 19 ~ 22 Is Fe-Ni-graphite-based powder (graphite amount: 3.3 to 17.1% by weight, graphite area ratio: 14 to 29%, Ni content: 0.91 to 12.2% by weight).
[0066]
Comparative example 34 , 3 9 Is a treating agent having a graphite content of less than 1% by weight. Comparative Example 3 5 ~ 3 7 , 3 9 , 40 Is a treating agent having a graphite content exceeding 20% by weight, of which Comparative Example 3 8 ~ 40 Is a treatment agent containing Ni (Ni amount: 2.1 to 12.3% by weight), and the specific surface area and particle size were the same as in the examples.
[0067]
Comparative Example 33, reference Example 15 , Example 19 ~ 22 In Comparative Examples 34 and 38, the molten metal was cast into a rod shape and then pulverized, and the other treatment agents were powders by a mechanical alloy method. The amount of each treatment agent added is 1 g (1% by weight with respect to the aqueous solution).
[0068]
As a method for analyzing the MC concentration, a head space method based on JIS K0125 (test method for volatile organic compounds in water and wastewater) was used, and the MC concentration was quantitatively analyzed over time. The measurement results are shown in Table 9, FIG. 9 (Fe-graphite system), Table 10, and FIG. 10 (Fe-Ni-graphite system).
[0069]
[Table 9]

[Table 10]

reference Example 15 ~ 17 After 3-7 days in the Fe-graphite system of Example 19 ~ 22 In the Fe-Ni-graphite system, the MC (1,1,1-trichloroethane) concentration after 2 to 6 days was less than 1 ppm of the soil environment standard. The decomposition product was mainly composed of ethane, but it was confirmed that no other organic chlorinated compounds of environmental standards were produced. Further, as a tendency, it was recognized that the treatment agent containing Ni has higher resolution. In contrast, Comparative Examples 34 and 38 were treatment agents having a graphite content of less than 1% by weight, but the MC (1,1,1-trichloroethane) concentration did not become less than 1 ppm even after 7 days. Comparative Examples 36 and 37 and Comparative Examples 39 and 40 were treatment agents having a graphite content exceeding 20% by weight, and the MC (1,1,1-trichloroethane) concentration did not become less than 1 ppm after 7 days.
[0070]
FIG. 9 shows the relationship between the graphite content in the treating agent and the MC solution concentration. It was found that the MC concentration was less than 1 ppm when the graphite content was 1 to 20% by weight. Fig. 10 shows the relationship between decomposition time and MC solution concentration. reference Example 15 , 17 , Example 19 , 22 Comparative Examples 34 and 38 are shown. It turns out that MC decomposes | disassembles in the Example for a short time, and the environmental standard value is less than 1 ppm.
[0071]
Therefore, Examples 19-22 The ability to decompose an aqueous solution containing MC (1,1,1-trichloroethane), which is said to be hardly degradable, is remarkable if the detoxifying agent used in the above is used, and the legal regulation value can be cleared in a short period of time. I understood that I could do it.
[0072]
【The invention's effect】
As is clear from the above description, according to the detoxification agent and detoxification treatment method of the present invention, organic halogen compounds in soil, sludge, and aqueous solution are decomposed in a short time, and no harmful by-products are generated. It has the effect of detoxifying treatment.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the TCE concentration and the graphite content in a treating agent in a TCE-containing aqueous solution.
FIG. 2 is a graph showing the change over time in the TCE behavior of Fe-graphite processing agents and Fe-Ni-graphite processing agents in a TCE-containing aqueous solution.
FIG. 3 is a graph showing the relationship between the TCE concentration and the graphite content in the treatment agent in the TCE-containing contaminated soil.
FIG. 4 is a graph showing changes over time in TCE behavior of Fe-graphite processing agents and Fe-Ni-graphite processing agents in TCE-containing contaminated soil.
FIG. 5 is a graph showing the relationship between the graphite content in the treating agent and the PCE concentration in the PCE-containing aqueous solution.
FIG. 6 is a graph showing changes over time in PCE behavior of an Fe-graphite processing agent and an Fe—Ni-graphite processing agent in a PCE-containing aqueous solution.
FIG. 7 is a graph showing the relationship between the graphite content in the treatment agent and the Cis-DCE concentration in the aqueous solution containing Cis-DCE.
FIG. 8 is a graph showing changes over time in the Cis-DCE behavior of the Fe-graphite processing agent and the Fe-Ni-graphite processing agent in a Cis-DCE-containing aqueous solution.
FIG. 9 is a graph showing the relationship between the graphite content in the treating agent and the MC concentration in the MC-containing aqueous solution.
FIG. 10 is a graph showing time-dependent changes in MC behavior of Fe-graphite processing agents and Fe-Ni-graphite processing agents in an MC-containing aqueous solution.

Claims

A detoxifying agent for an object to be treated, which is made of graphite and Fe—Ni, contaminated with an organic halogen compound having a graphite content of 2 to 17.3% by weight and a particle size of 200 μm or less.

Detoxifying agents for the treatment of claim 1, wherein the Ni content is 0.1 to 15 wt%.

Detoxifying agents for the treatment of the claims 1 or claim 2, wherein the graphite area ratio is 2 to 30% in the measurement by microscope test method shown in JIS-G0555.

An object to be treated contaminated with an organic halogen compound is treated with the detoxifying agent according to any one of claims 1 to 3 , and the object to be treated contaminated with an organic halogen compound is detoxified. Method.

Detoxifying agent according to any one of claims 1 to 3 is a powder, according to claim 4, wherein the amount of its addition is 0.1 to 10% by weight relative to the object to be processed A detoxification method for an object to be treated contaminated with an organic halogen compound.