JP4114763B2 - Method for removing germanium in aqueous solution - Google Patents

Description

［式中、Ｒ¹は水素原子、炭素数１〜４のアルキル基、ヒドロキシエチル基、またはヒドロキシプロピル基、Ｒ²は炭素数１〜４のアルキル基、ヒドロキシエチル基、またはヒドロキシプロピル基を表し、Ｒ¹とＲ²とは同一もしくは異なる基であってもよい］。
【０００６】
上記式（１）で示される基の中でも好ましいのは、該式（１）中のＲ¹およびＲ²がいずれもヒドロキシエチル基であるもの、或いはＲ¹が水素原子またはメチル基、Ｒ²がヒドロキシエチル基であるものである。
【０００７】
上記式（１）で示される基は、繊維分子中の反応性官能基（ヒドロキシル基、アミノ基、イミノ基、アルデヒド基、カルボキシル基、チオール基など）等に直接結合していてもよく、あるいは繊維分子中にエポキシ基、反応性二重結合、ハロゲン基、酸無水物から選ばれる２個以上の官能基を有する架橋剤を介して間接的に結合していても構わない。
【０００８】
上記除去法を実施することによってゲルマニウムを捕捉したキレート形成性繊維は、酸水溶液を用いて処理することによってゲルマニウムを簡単に溶離させることができるので、この方法を採用すれば、キレート形成性繊維を簡単に再生できるばかりでなく、溶離液からゲルマニウムを高濃度で回収することも可能となる。
【０００９】
【発明の実施の形態】
本発明にかかるゲルマニウムの除去法は、上記の様に、繊維分子中に前記式（１）で示される基、より好ましくは、式（１）中のＲ¹およびＲ²がいずれもヒドロキシエチル基、あるいはＲ¹が水素原子またはメチル基で、Ｒ²がヒドロキシエチル基である基が導入されたキレート形成性繊維を、ゲルマニウムを含有するｐＨ３〜１２の水溶液と接触させ、水溶液中のゲルマニウムを捕捉除去するところに特徴を有している。
【００１０】
即ち本発明では、前記式（１）で示される基が、特定ｐＨ領域でゲルマニウムに対して高いキレート形成能を発揮することを活用し、該基を繊維分子中に導入することによって、水溶液中のゲルマニウムを効率よく捕捉除去することに成功したものである。
【００１１】
本発明で用いる前記式（１）で示される基が導入される繊維の種類は特に制限されず、例えば綿、麻などを始めとする種々の植物繊維；絹、羊毛などを始めとする種々の動物性繊維；ビスコースレーヨンなどを始めとする種々の再生繊維；ポリアミド、アクリル、ポリエステルなどを始めとする様々の合成繊維を使用することができ、これらの繊維は必要に応じて各種の変性を加えたものであっても構わないが、前記式（１）で示される基の導入のし易さ、被処理液の濡れ性、強度、安定性を考慮して最も好ましいのはセルロース系繊維である。
【００１２】
上記ベース繊維の性状にも格別の制限はなく、長繊維のモノフィラメント、マルチフィラメント、短繊維の紡績糸あるいはこれらを織物状もしくは編物状に製織もしくは製編した布帛、更には不織布であってもよい。また、２種以上の繊維を複合もしくは混紡した繊維や織・編物であってもよい。
【００１３】
更に該キレート形成性繊維と被処理水溶液との接触効率を上げるため、上記基材繊維を短繊維状の粉末あるいはフィルター状の素材として使用することも有効である。
【００１４】
ここで用いられる短繊維状粉末の好ましい形状は、長さ０．０１〜５ｍｍ、より好ましくは０．０３〜３ｍｍで、単繊維径が１〜５０μｍ程度、より好ましくは５〜３０μｍであり、アスペクト比としては１〜６００程度、より好ましくは１〜１００程度のものである。
【００１５】
この様な短繊維状の粉末素材を使用すれば、ゲルマニウムを含む水性液に該短繊維粉末状のキレート形成性繊維を添加して攪拌し、通常の濾過処理を行うという非常に簡単な方法で、且つ短時間の処理で被処理水中に含まれるゲルマニウムを効率よく捕捉して清浄化することができる。また場合によっては、該短繊維粉末状のキレート形成性繊維をカラム等に充填して被処理水を通過させることによっても、同様にゲルマニウムを捕捉できる。
【００１６】
またフィルター状の素材も格別特殊なものではなく、その用途に応じて任意の繊維間隙を有する織・編物もしくは不織布などからなる単層もしくは複層構造のマット状に成形して適当な支持体に組み付けた構造、あるいは通水性支持筒の外周側に紐状の繊維を綾巻状に複数層巻回した構造、または同繊維からなる織・編物もしくは不織布シートをプリーツ状に折り曲げて支持部材に装着した構造、同繊維を用いて作製した織・編物や不織布を袋状に成形したバグフィルタータイプなど、公知のあらゆる形態のものが使用できる。
【００１７】
本発明において、ベース繊維に前記式（１）で示される基を導入する際に使用するアミノ化合物としては、前記式（２）で示されるアミノ化合物が使用され、例えば各種アミンにエチレンオキサイドやプロピレンオキサイドを付加させたものを用いることができる。しかし、ゲルマニウムとのキレート形成能や繊維分子との反応性、コスト等を総合的に考えて最も実用的なのは、ジエタノールアミン、モノエタノールアミン、Ｎ−メチルエタノールアミンである。
【００１８】
これらキレート形成能を与えるため繊維分子中に導入される基は、繊維分子中の反応性官能基（例えば、ヒドロキシル基、アミノ基、イミノ基、カルボキシル基、アルデヒド基、チオール基など）等に直接結合していてもよく、あるいは架橋剤を介して間接的に結合していても構わないが、繊維分子への導入の容易性を考えると、後述する様な架橋剤を介して間接的に導入したものが、実用性の高いものとして推奨される。
【００１９】
本発明で用いる上記キレート形成性繊維を製造する方法としては、繊維分子が元々有している前述の様な反応性官能基もしくは変性によって導入した反応性官能基に、前記アミノ化合物を直接反応させ、あるいは、該反応性官能基に、架橋剤として分子中にエポキシ基、反応性二重結合、ハロゲン基、酸無水物基から選ばれる２個以上の官能基を有する化合物を反応させた後、前記アミノ化合物を反応させる方法などが採用される。
【００２０】
これらの架橋剤を用いて前記式（１）で示される基を繊維に導入する際の反応は特に制限されないが、好ましい方法を挙げると、ベース繊維と前記架橋剤を水あるいはＮ，Ｎ’−ジメチルホルムアミドやジメチルスルホキシド等の極性溶媒中で、必要により反応触媒や乳化剤などを併用して、６０〜１００℃程度で３０分〜数十時間程度反応させる方法であり、この反応により、架橋剤が繊維分子中の反応性官能基（例えば、ヒドロキシル基やアミノ基など）と反応して繊維と結合し、前記アミノ化合物と容易に反応する官能基を繊維分子中に導入することができる。次いで、該官能基を導入した繊維と前記アミノ化合物を、水やＮ，Ｎ’−ジメチルホルムアミド、ジメチルスルホキシド等の極性溶媒中で、必要により反応触媒を用いて６０〜１００℃で３０分〜数十時間程度反応させると、前記アミノ化合物のアミノ基が架橋剤の反応性官能基（例えばエポキシ基やハロゲン基など）と反応し、ゲルマニウムに対してキレート形成能を有する基が繊維分子中にペンダント状に導入される。
【００２１】
上記の様にして得られるキレート形成性繊維は、用いるベース繊維の性状に応じてモノフィラメント状、マルチフィラメント状、紡績糸状、不織布状、繊維織・編物状など任意の性状のものとして得ることができるが、いずれにしても細径の繊維分子表面にペンダント状に導入された前述のキレート形成性を有する基の実質的に全てが、ゲルマニウム捕捉性能を有効に発揮するので、例えば顆粒状やフィルム状などのキレート形成性樹脂に比べると非常に優れた除去性能を発揮する。
【００２２】
従ってこの繊維をゲルマニウムを含む水溶液と接触させ、具体的には該繊維を任意の厚さで積層したり或はカラム内に充填して被処理液を通す方法、あるいは短繊維粉末状の該繊維を被処理液に添加して攪拌し、通常の濾過処理を行うという非常に簡単な方法で、且つ短時間の処理で被処理水中に含まれるゲルマニウムを効率よく捕捉して清浄化することができる。
【００２３】
なお本発明を実施するに当たり、水溶液中に含まれるゲルマニウムイオンもしくはその化合物を前記キレート形成性繊維によって効率よく除去するには、該水溶液のｐＨを３〜１２に調整することが必須となる。ちなみに該水溶液のｐＨが３未満の酸性側でも、またｐＨが１２を超える強アルカリ側でも、前記キレート形成性繊維のゲルマニウムイオンに対するキレート形成能が有効に発揮されず、満足のいくゲルマニウム除去効果が得られないからである。
【００２４】
上記の様にしてゲルマニウムを捕捉したキレート形成性繊維は、例えば塩酸水溶液や硫酸水溶液で処理すると、キレートを形成して捕捉されたゲルマニウム成分は簡単に離脱するので、こうした特性を利用すれば該繊維を簡単に再生することができ、更に溶出液からゲルマニウムを有価成分として有効に回収することも可能となる。
【００２５】
【実施例】
次に本発明の実施例を示すが、本発明はもとより下記実施例によって制限を受けるものではなく、前後記の趣旨に適合し得る範囲で適当に変更を加えて実施することも勿論可能であり、それらはいずれも本発明の技術的範囲に含まれる。
【００２６】
（キレート形成性繊維の合成例１）
蒸留水１０００ｍｌに、硫酸第一鉄アンモニウム六水和物０．０２５ｇを溶解後、綿糸（染色試材社製 ４０／１綿単糸晒品）５０ｇを添加し、室温で３０分撹拌後、メタクリル酸グリシジル５０ｇ、非イオン系界面活性剤（日本油脂社製ノニオン「ＯＴ−２２１」）１ｇ、３１％Ｈ₂Ｏ₂水０．８１ｇ、二酸化チオ尿素０．３１ｇを添加し、６０℃で1時間撹拌する。次いで、処理を終えた綿糸を蒸留水で洗浄し、脱液した後５０℃で１５時間乾燥することにより、グリシジルメタクリレートがグラフトしたグラフト繊維６８．０ｇを得た。
【００２７】
次に、蒸留水３５０ｇ、ジメチルスルホキシド３５０ｇの混合溶媒にモノエタールアミン３００ｇを溶解させた溶液に上記グラフト繊維を浸漬し、８０℃で２時間加熱処理する。次いで十分に水洗し脱液した後、５０℃で１５時間乾燥することにより、キレート形成性繊維（キレート繊維Ａ）７３．２ｇ（置換率：４６．４質量％）を得た。
【００２８】
（キレート形成性繊維の合成例２）
前記合成例１において、モノエタノールアミンをジエタノールアミンに代えた以外はすべて同様にして、キレート形成性繊維（キレート繊維Ｂ）７８．０ｇ（置換率：５６．０質量％）を得た。
【００２９】
実施例１
（バッチ式でのゲルマニウム吸着性能試験１）
前記合成例１で得たキレート繊維Ａ５０ｍｇを、１０ｍｍｏｌ／ｌのゲルマニウム(IV)、ほう素(III)およびテルル(VI)を含む０．１ｍｏｌ／ｌの塩化カリウム溶液２５ｍｌに添加し、更に塩酸または水酸化ナトリウム水溶液を用いてｐＨを変化させ２５℃で２４時間攪拌を行った後、水溶液中に残存するゲルマニウムを定量することによって、各ｐＨでの吸着量を確認した。結果は図１に示す通りであり、水溶液ｐＨを３〜１２の範囲、より好ましくはｐＨが５〜１０の範囲に調整して処理することにより、ゲルマニウムを選択的に効率よく吸着・除去できることが分かる。
【００３０】
実施例２
（バッチ式でのゲルマニウム吸着性能試験２）
前記実施例１のキレート繊維Ａに代えてキレート繊維Ｂを用いた以外は同様にして、吸着試験を行なった。結果は図２に示す通りであり、水溶液ｐＨを５〜１２の範囲、より好ましくはｐＨが６〜１１の範囲に調整して処理することにより、ゲルマニウムを選択的に効率よく吸着・除去できることが確認された。
【００３１】
実施例３
（破過曲線測定試験）
前記合成例で得られたキレート繊維Ｂを内径５ｍｍのガラスカラム内に１．８ｍｌ充填し、１ｍｍｏｌ／ｌのゲルマニウム(IV)、ほう素(III)、テルル(VI)をそれぞれ含んだ０．１ｍｏｌ／ｌの塩化アンモニウム−アンモニア緩衝液（ｐＨを８．６に調整）をＳＶ＝７５ｈｒ^-1の流速で流し、流出液中の各元素の濃度を測定することによって破過曲線を求め、図３に示す結果を得た。
【００３２】
また比較のため、キレート繊維Ｂに代えて市販のビーズ状スチレン系グルカミン型キレート樹脂（三菱化学社製商品名「ダイヤイオンＣＲＢ０２」）１．３ｍｌを用いて同様の試験を行った。市販キレート樹脂の場合は、キレート繊維Ｂの条件に合わせたＳＶ＝７５ｈｒ‐¹の流速と、実際の使用条件に合わせたＳＶ＝１０ｈｒ‐¹の流速でそれぞれ試験を行ない、図４、図５に示す結果を得た。
【００３３】
破過曲線を示す図３と図４、図５を比較すれば明らかな様に、市販のキレート樹脂を用いたカラム式除去法では、ＳＶ＝７５ｈｒ^-1という高流速においてはゲルマニウム、ほう素、テルルのいずれもほとんど吸着されずに流出してしまい、またＳＶ＝１０ｈｒ‐¹においてはゲルマニウム、ほう素、テルルのいずれも保持されてしまうのに対し、本発明のキレート繊維Ｂを用いたカラム式除去法では、ＳＶ＝７５ｈｒ^-1という高流速においても、ほう素およびテルルは全く吸着されないうちに流出するが、ゲルマニウムは吸着量が飽和に達するまでは完全に吸着除去されており、この結果からも明らかな様に本発明のキレート形成性繊維は、ゲルマニウムに対して特に優れた選択吸着性能を有していることがわかる。
【００３４】
【発明の効果】
本発明は以上の様に構成されており、本発明の除去方法を用いれば、ゲルマニウムを高い選択吸着性で除去できるばかりでなく、吸着速度も格段に優れており、従来のイオン交換樹脂やキレート樹脂に較べて用排水中のゲルマニウムを極めて効率よく捕捉・除去することができ、それらを極めて効率よく清浄化することができる。しかも、該成分を捕捉した本発明のキレート形成性繊維は、酸水溶液による処理によって簡単に該成分を離脱するので、その再生が簡単で繰り返し使用できるばかりでなく、該成分の濃縮採取にも利用することができる。また不織布状もしくは布帛状等のキレート形成性繊維を使用すれば、これらをカートリッジ方式として交換その他の作業性を高めることも容易であり、更には繰り返し使用によって捕捉性能を失った場合は、通常の焼却炉などによって簡単に焼却処分することができる。
【図面の簡単な説明】
【図１】実施例１で得た元素吸着量とｐＨの関係を示すグラフである。
【図２】実施例２で得た元素吸着量とｐＨの関係を示すグラフである。
【図３】実施例３で得た処理液量と元素濃度の関係を示すグラフである。
【図４】実施例３で対照例として用いた市販のキレート樹脂を用いた場合の処理液量と元素濃度の関係を示すグラフである。
【図５】実施例３で対照例として用いた市販のキレート樹脂を使用し、処理流速を変えた場合の処理液量と元素濃度の関係を示すグラフである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for efficiently removing germanium in an aqueous solution using a chelate-forming fiber into which a specific chelate-forming functional group has been introduced. With this removal method, germanium that is present in a trace amount in water is selected. It can be removed efficiently, for example, industrial and agricultural water, wastewater purification, and resource recovery can be widely applied industrially.
[Prior art]
Germanium is widely used in various fields as an industrial raw material, such as polyester polymerization catalysts, semiconductor materials such as transistors and diodes, and synthetic silica doping materials for optical fibers. As a rare element, recovery technology is required in each field. ing. In addition, in the electrolytic refining process of zinc, germanium contained in zinc ore as an impurity significantly reduces the current efficiency during electrolysis, and therefore it is desired to remove germanium from the electrolytic solution.
[0003]
Conventionally, as a simple method for separating germanium in an aqueous solution, D.I. A. Everest and J.M. E. Salmon, J.M. Chem. Soc. , 1954, 2438, or G. Kraft, H .; Doshand K.K. Gabbent, Z .; Anal. Chem. , 267, 106 (1973) and J. Org. Seidl, J .; Stamberg and E.M. Hrbkova, J .; Appl. Chem. , 12,500 (1962). Although it is possible to adsorb germanium according to these methods, the selective adsorption property of germanium is poor, and since the resin as the base material is in the form of beads or particles, the liquid containing germanium is contained inside the base material. Since it takes a long time to impregnate, the adsorption rate was low, and efficient germanium capture was not possible.
[0004]
[Problems to be solved by the invention]
The present invention has been made paying attention to the above-described circumstances, and an object of the present invention is to provide a method capable of efficiently removing germanium contained in a trace amount in an aqueous solution by a simple method.
[0005]
[Means for Solving the Problems]
The method for removing germanium according to the present invention that has solved the above problems uses a chelate-forming fiber having a group represented by the following formula (1) in the molecule, and this is adjusted to pH 3-12. The present invention is summarized in that germanium is removed by contacting with an aqueous solution containing germanium.

[Wherein, R ¹ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyethyl group, or a hydroxypropyl group, and R ² represents an alkyl group having 1 to 4 carbon atoms, a hydroxyethyl group, or a hydroxypropyl group. R ¹ and R ² may be the same or different groups.
[0006]
Among the groups represented by the formula (1), R ¹ and R ² in the formula (1) are both hydroxyethyl groups, or R ¹ is a hydrogen atom or a methyl group, and R ² is It is a hydroxyethyl group.
[0007]
The group represented by the above formula (1) may be directly bonded to a reactive functional group (hydroxyl group, amino group, imino group, aldehyde group, carboxyl group, thiol group, etc.) in the fiber molecule, or The fiber molecule may be indirectly bonded via a crosslinking agent having two or more functional groups selected from an epoxy group, a reactive double bond, a halogen group, and an acid anhydride.
[0008]
Since the chelate-forming fiber capturing germanium by carrying out the above removal method can be easily eluted by treating with an acid aqueous solution, if this method is employed, the chelate-forming fiber is In addition to being easily regenerated, germanium can be recovered from the eluent at a high concentration.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In the method for removing germanium according to the present invention, as described above, the group represented by the formula (1) in the fiber molecule, more preferably, R ¹ and R ² in the formula (1) are both hydroxyethyl groups. Alternatively, the chelate-forming fiber into which R ¹ is a hydrogen atom or a methyl group and R ² is a hydroxyethyl group is brought into contact with an aqueous solution containing germanium and having a pH of 3 to 12 to trap germanium in the aqueous solution. It is characterized by its removal.
[0010]
That is, in the present invention, utilizing the fact that the group represented by the formula (1) exhibits a high chelate-forming ability with respect to germanium in a specific pH region, and introducing the group into the fiber molecule, The germanium was successfully captured and removed.
[0011]
The type of fiber into which the group represented by the formula (1) used in the present invention is introduced is not particularly limited, and various plant fibers such as cotton and hemp; various types including silk and wool Animal fibers; various recycled fibers including viscose rayon; various synthetic fibers including polyamide, acrylic, polyester, etc. can be used, and these fibers can be modified as required. Cellulose fibers are the most preferable in consideration of the ease of introduction of the group represented by the formula (1), the wettability, strength, and stability of the liquid to be treated. is there.
[0012]
The properties of the base fiber are not particularly limited, and may be a long-fiber monofilament, multifilament, short-fiber spun yarn, a fabric woven or knitted into a woven or knitted shape, or a non-woven fabric. . Further, it may be a fiber or a woven / knitted fabric obtained by combining or blending two or more kinds of fibers.
[0013]
Furthermore, in order to increase the contact efficiency between the chelate-forming fiber and the aqueous solution to be treated, it is also effective to use the base fiber as a short fiber powder or a filter material.
[0014]
The preferred shape of the short fibrous powder used here is 0.01 to 5 mm in length, more preferably 0.03 to 3 mm, and the single fiber diameter is about 1 to 50 μm, more preferably 5 to 30 μm. The ratio is about 1 to 600, more preferably about 1 to 100.
[0015]
If such a short fiber powder material is used, the chelate-forming fiber in the form of short fiber powder is added to an aqueous liquid containing germanium, stirred, and subjected to a normal filtration process. In addition, germanium contained in the water to be treated can be efficiently captured and cleaned in a short time treatment. In some cases, germanium can be captured in the same manner by filling the chelate-forming fibers in the form of short fiber powder into a column or the like and allowing the water to be treated to pass through.
[0016]
In addition, the filter-like material is not particularly special, and depending on its use, it is formed into a single-layer or multi-layer mat made of woven, knitted or non-woven fabric having an arbitrary fiber gap to form an appropriate support. An assembled structure, or a structure in which multiple layers of string-like fibers are wound around the outer periphery of a water-permeable support cylinder, or a woven / knitted or non-woven sheet made of the same fiber is folded into a pleat shape and attached to a support member Any known form such as a bag filter type in which the structure, a woven or knitted fabric produced using the same fiber, and a nonwoven fabric formed into a bag shape can be used.
[0017]
In the present invention, as the amino compound used when the group represented by the formula (1) is introduced into the base fiber, the amino compound represented by the formula (2) is used. For example, various amines include ethylene oxide and propylene. What added the oxide can be used. However, diethanolamine, monoethanolamine, and N-methylethanolamine are the most practical in terms of chelate-forming ability with germanium, reactivity with fiber molecules, cost, and the like.
[0018]
The group introduced into the fiber molecule to give these chelate forming ability is directly connected to a reactive functional group (for example, hydroxyl group, amino group, imino group, carboxyl group, aldehyde group, thiol group, etc.) in the fiber molecule. It may be bonded or indirectly bonded via a cross-linking agent, but considering the ease of introduction into the fiber molecule, it is indirectly introduced via a cross-linking agent as described below. Is recommended as a highly practical one.
[0019]
As a method for producing the chelate-forming fiber used in the present invention, the amino compound is directly reacted with the reactive functional group originally contained in the fiber molecule or the reactive functional group introduced by modification. Alternatively, after reacting the reactive functional group with a compound having two or more functional groups selected from an epoxy group, a reactive double bond, a halogen group, and an acid anhydride group in the molecule as a crosslinking agent, A method of reacting the amino compound is employed.
[0020]
The reaction when the group represented by the formula (1) is introduced into the fiber using these cross-linking agents is not particularly limited. However, when a preferable method is mentioned, the base fiber and the cross-linking agent are mixed with water or N, N′— In a polar solvent such as dimethylformamide or dimethyl sulfoxide, a reaction catalyst or an emulsifier is used in combination, if necessary, and the reaction is carried out at about 60 to 100 ° C. for about 30 minutes to several tens of hours. A functional group that reacts with a reactive functional group (for example, a hydroxyl group or an amino group) in the fiber molecule to bind to the fiber and easily reacts with the amino compound can be introduced into the fiber molecule. Subsequently, the fiber into which the functional group is introduced and the amino compound are mixed in water, a polar solvent such as N, N′-dimethylformamide, dimethyl sulfoxide, and the like at 60 to 100 ° C. for 30 minutes to several times using a reaction catalyst as necessary. When reacted for about 10 hours, the amino group of the amino compound reacts with a reactive functional group of the cross-linking agent (for example, epoxy group or halogen group), and a group capable of forming a chelate with respect to germanium is pendant in the fiber molecule. Introduced into the shape.
[0021]
The chelate-forming fiber obtained as described above can be obtained as an arbitrary property such as a monofilament shape, a multifilament shape, a spun yarn shape, a nonwoven fabric shape, a fiber woven or knitted shape, depending on the properties of the base fiber to be used. However, in any case, substantially all of the aforementioned chelate-forming groups introduced in a pendant form on the surface of the fine fiber molecule effectively exhibit germanium scavenging performance. It exhibits very good removal performance compared to chelate-forming resins such as
[0022]
Therefore, this fiber is brought into contact with an aqueous solution containing germanium, specifically, the fiber is laminated at an arbitrary thickness, or the column is filled into the column and the liquid to be treated is passed, or the fiber in the form of short fiber powder Can be efficiently trapped and cleaned of germanium contained in the water to be treated by a very simple method of adding and stirring the liquid to the liquid to be treated and performing a normal filtration treatment, and in a short time treatment. .
[0023]
In carrying out the present invention, it is essential to adjust the pH of the aqueous solution to 3 to 12 in order to efficiently remove germanium ions or compounds thereof contained in the aqueous solution by the chelate-forming fibers. Incidentally, the chelate-forming ability of the chelate-forming fiber with respect to germanium ions is not exhibited effectively even on the acidic side of the aqueous solution having a pH of less than 3 or on the strong alkali side having a pH of more than 12, and a satisfactory germanium removal effect is obtained. It is because it cannot be obtained.
[0024]
When the chelate-forming fiber capturing germanium as described above is treated with, for example, an aqueous hydrochloric acid solution or an aqueous sulfuric acid solution, the germanium component captured by forming a chelate is easily released. Can be easily regenerated, and germanium can be effectively recovered from the eluate as a valuable component.
[0025]
【Example】
Next, examples of the present invention will be shown. However, the present invention is not limited by the following examples as a matter of course, and it is needless to say that the present invention can be implemented with appropriate modifications within a range that can meet the gist of the preceding and following descriptions. These are all included in the technical scope of the present invention.
[0026]
(Synthesis example 1 of chelate-forming fiber)
After dissolving 0.025 g of ferrous ammonium sulfate hexahydrate in 1000 ml of distilled water, 50 g of cotton yarn (40/1 cotton single yarn bleached product manufactured by Dyeing Materials Co., Ltd.) is added, stirred at room temperature for 30 minutes, and then methacrylic. Add 50 g of glycidyl acid, 1 g of nonionic surfactant (Nonion “OT-221” manufactured by NOF Corporation), 0.81 g of 31% H ₂ O ₂ water, 0.31 g of thiourea dioxide and add at 60 ° C. for 1 hour. Stir. Next, the treated cotton yarn was washed with distilled water, drained, and dried at 50 ° C. for 15 hours to obtain 68.0 g of graft fiber grafted with glycidyl methacrylate.
[0027]
Next, the graft fiber is immersed in a solution in which 300 g of monoethalamine is dissolved in a mixed solvent of 350 g of distilled water and 350 g of dimethyl sulfoxide, and heat-treated at 80 ° C. for 2 hours. Next, after sufficiently washing with water and draining, it was dried at 50 ° C. for 15 hours to obtain 73.2 g (substitution rate: 46.4% by mass) of a chelate-forming fiber (chelate fiber A).
[0028]
(Synthesis example 2 of chelate-forming fiber)
Except that monoethanolamine was replaced with diethanolamine in Synthesis Example 1, 78.0 g of chelate-forming fiber (chelate fiber B) (substitution rate: 56.0% by mass) was obtained.
[0029]
Example 1
(Batch type germanium adsorption performance test 1)
50 mg of the chelate fiber A obtained in Synthesis Example 1 was added to 25 ml of a 0.1 mol / l potassium chloride solution containing 10 mmol / l germanium (IV), boron (III), and tellurium (VI), and further hydrochloric acid or After changing the pH using an aqueous sodium hydroxide solution and stirring at 25 ° C. for 24 hours, the amount of germanium remaining in the aqueous solution was quantified to confirm the amount of adsorption at each pH. The results are as shown in FIG. 1, and germanium can be selectively adsorbed and removed efficiently by adjusting the aqueous solution pH in the range of 3 to 12, more preferably in the range of 5 to 10. I understand.
[0030]
Example 2
(Batch type germanium adsorption performance test 2)
An adsorption test was performed in the same manner except that the chelate fiber B was used instead of the chelate fiber A of Example 1. The results are as shown in FIG. 2, and germanium can be selectively adsorbed and removed efficiently by adjusting the aqueous solution pH in the range of 5 to 12, more preferably in the range of 6 to 11. confirmed.
[0031]
Example 3
(Breakthrough curve measurement test)
The chelate fiber B obtained in the above synthesis example was packed in 1.8 ml in a glass column having an inner diameter of 5 mm, and 0.1 mol each containing 1 mmol / l germanium (IV), boron (III), and tellurium (VI). / L ammonium chloride-ammonia buffer (pH adjusted to 8.6) was flowed at a flow rate of SV = 75 hr ⁻¹ , and the breakthrough curve was determined by measuring the concentration of each element in the effluent. The result shown in was obtained.
[0032]
For comparison, a similar test was performed using 1.3 ml of a commercially available bead-like styrene-based glucamine type chelate resin (trade name “Diaion CRB02” manufactured by Mitsubishi Chemical Corporation) instead of the chelate fiber B. For commercial chelating resin, it was used as an SV = 75hr- ¹ flow rate to match the conditions of the chelate fiber B, and each test with combined SV = 10hr- ¹ flow rate in actual use conditions, Fig. 4, FIG. 5 The results shown are obtained.
[0033]
As is clear from comparison between FIG. 3 showing the breakthrough curve, FIG. 4, and FIG. 5, in the column-type removal method using a commercially available chelate resin, at a high flow rate of SV = 75 hr ⁻¹ , germanium, boron, All of the tellurium flows out without being adsorbed, and at SV = 10 hr- ¹ , all of germanium, boron and tellurium are retained, whereas the column type using the chelate fiber B of the present invention is used. In the removal method, even at a high flow rate of SV = 75 hr ⁻¹ , boron and tellurium flow out before being adsorbed at all, but germanium is completely adsorbed and removed until the adsorption amount reaches saturation. As is apparent, the chelate-forming fiber of the present invention has a particularly excellent selective adsorption performance with respect to germanium.
[0034]
【The invention's effect】
The present invention is configured as described above. If the removal method of the present invention is used, germanium can be removed with a high selective adsorption property, and the adsorption rate is remarkably excellent. As compared with the resin, germanium in the effluent can be captured and removed very efficiently, and they can be cleaned very efficiently. In addition, the chelate-forming fiber of the present invention that captures the component can be easily and repeatedly used because it is easily removed by treatment with an aqueous acid solution, and can also be used for concentration and collection of the component. can do. If chelating fibers such as non-woven fabrics or fabrics are used, it is easy to replace them with a cartridge system and improve other workability. Furthermore, if the capture performance is lost by repeated use, It can be easily incinerated with an incinerator.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the amount of element adsorption obtained in Example 1 and pH.
2 is a graph showing the relationship between the amount of element adsorption obtained in Example 2 and pH. FIG.
FIG. 3 is a graph showing the relationship between the amount of treatment liquid obtained in Example 3 and the element concentration.
4 is a graph showing the relationship between the amount of treatment liquid and element concentration when a commercially available chelate resin used as a control example in Example 3 is used. FIG.
FIG. 5 is a graph showing the relationship between the amount of treatment liquid and the element concentration when a commercially available chelate resin used as a control example in Example 3 is used and the treatment flow rate is changed.

Claims (5)

Have a group represented by the following formula in the cellulose fiber molecules (1), the reactive functional groups of the group in the fiber molecule represented by the following formula (1), epoxy groups in the molecule and a reactive double the chelate-forming fiber that has been introduced through the cross-linking agent having a binding, is contacted with germanium-containing aqueous solution is adjusted to PH3～12, germanium in aqueous solution, characterized in that the removal of the germanium in the aqueous solution Removal method.
-N-R ²
｜ …… (1)
R ¹
[Wherein, R ¹ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyethyl group, or a hydroxypropyl group, and R ² represents an alkyl group having 1 to 4 carbon atoms, a hydroxyethyl group, or a hydroxypropyl group. R ¹ and R ² may be the same or different groups] The removal method according to claim 1, wherein R ¹ and R ² in the formula (1) are both hydroxyethyl groups. The removal method according to claim 1, wherein R ¹ in the formula (1) is a hydrogen atom or a methyl group, and R ² is a hydroxyethyl group. The crosslinking agent is, removal method according to claim 1 is at least one selected glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether by Li Cheng group. After performing removal method according to any one of claims 1 to 4, eluting the germanium from the chelate-forming fiber with an aqueous acid solution, reproducing method of chelate forming fiber.

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