JP3902069B2 - Method for treating wastewater containing N, N-dimethylformamide - Google Patents
Method for treating wastewater containing N, N-dimethylformamide Download PDFInfo
- Publication number
- JP3902069B2 JP3902069B2 JP2002153572A JP2002153572A JP3902069B2 JP 3902069 B2 JP3902069 B2 JP 3902069B2 JP 2002153572 A JP2002153572 A JP 2002153572A JP 2002153572 A JP2002153572 A JP 2002153572A JP 3902069 B2 JP3902069 B2 JP 3902069B2
- Authority
- JP
- Japan
- Prior art keywords
- dimethylformamide
- waste water
- wastewater
- dmf
- extraction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Description
【０００１】
【発明の属する技術分野】
本発明は、溶剤や反応溶媒等に広く用いられているＮ，Ｎ−ジメチルホルムアミドを含む廃水を処理し、Ｎ，Ｎ−ジメチルホルムアミドを回収し、Ｎ，Ｎ−ジメチルホルムアミド含有廃水の化学的酸素要求量と全窒素濃度とを低減させる処理方法に関する。
【０００２】
【従来の技術】
Ｎ，Ｎ−ジメチルホルムアミド（以下、ＤＭＦと略記することがある。）は、水に可溶な有機溶媒として、工業的に広く利用されている。ＤＭＦを製造あるいは使用した工程においては、排出される廃水にＤＭＦが含まれる場合があるが、ＤＭＦを含んだ廃水は化学的酸素要求量（以下、ＣＯＤと略記することがある。）及び全窒素濃度が高く、環境汚染防止の観点から何らかの浄化処理を行う必要がある。
【０００３】
一般的な廃水の浄化処理方法としては、微生物に分解を行わせる活性汚泥処理法があるが、ＤＭＦ濃度の変化に対して極めて鋭敏であり管理が難しい上に、ＤＭＦを回収・再利用することができないという欠点がある。
【０００４】
また、ＤＭＦを含有する廃水をそのまま燃焼する処理方法もあるが、一般に廃水中のＤＭＦ濃度は低く、燃焼過程において水分の蒸発に多大なエネルギーを要し経済的でない上に、ＤＭＦを回収することもできず、有利な方法といえない。
【０００５】
さらに、水分を蒸留除去することにより、有機物を廃水より除去すると同時にＤＭＦも回収する方法が知られている。この方法であれば、ＤＭＦの回収はできるものの、やはり水分の蒸発に多大なエネルギーを要し経済的でない。
【０００６】
上記の技術が有する問題点を解消する方法として、水不溶の抽出剤を用いて、廃水中のＤＭＦを抽出し、その後抽出剤とＤＭＦとを蒸留分離することにより、廃水を浄化処理するとともにＤＭＦを回収する方法が知られており、特開昭５３−７７００６号公報には、水溶液中のＤＭＦを置換フェノールにより抽出する方法が開示され、特開昭５５−１４１４５０号公報には、ピロール、アニリン、ペンタノール等を抽出剤として、アルキルアミドを抽出する方法が開示されている。しかしながら、これらの抽出方法を用い、抽出による浄化処理を繰り返しても充分に浄化することができないという問題があった。
【０００７】
【発明が解決しようとする課題】
本発明の目的は、上記従来技術が有していた問題を解決し、Ｎ，Ｎ−ジメチルホルムアミド含有廃水を溶剤抽出法にて処理して、該廃水のＣＯＤ及び全窒素濃度を効果的に低減させる方法を提供することにある。
【０００８】
【課題を解決するための手段】
本発明者らは、上記従来技術に鑑み鋭意検討を重ねた結果、廃水中には、Ｎ，Ｎ−ジメチルホルムアミドの加水分解によって、ジメチルアミン、ジメチルアンモニウムイオン、ギ酸及びギ酸イオンが生じており、これらの存在がＣＯＤ及び全窒素濃度の低減を妨げていたことを見出し、本発明を完成するに至った。
【０００９】
すなわち、本発明の目的は、
ジメチルアミン、ジメチルアンモニウムイオン、ギ酸及びギ酸イオンからなる群から選ばれた少なくとも一種の有機化合物並びにＮ，Ｎ−ジメチルホルムアミドを含有する廃水の化学的酸素要求量と全窒素濃度とを低減させる処理方法であって、該廃水中の有機化合物濃度を予め０．０５重量％以下となるように調整した後、溶媒抽出を実施して、廃水からＮ，Ｎ−ジメチルホルムアミドを除去することを特徴とする、Ｎ，Ｎ−ジメチルホルムアミド含有廃水の化学的酸素要求量と全窒素濃度とを低減させる処理方法によって達成することができる。
【００１０】
【発明の実施の形態】
以下、本発明につき、詳細に説明する。
本発明の処理方法を適用しようとする処理対象廃水は、ＤＭＦと、ジメチルアミン及び／又はギ酸を含有しているものである。ここで、ジメチルアミンは廃水中でジメチルアンモニウムイオン、ギ酸は廃水中でギ酸イオンの形態で存在していてもよい。
【００１１】
これら、ジメチルアミン、ジメチルアンモニウムイオン、ギ酸及びギ酸イオンの合計濃度が０．０５重量％を超える廃水に対して本発明の処理方法を適用すればよく、該濃度が０．０５重量％以下の場合は本発明の処理方法を用いる必要はない。また、処理すべき廃水は、ＤＭＦ、ジメチルアミン、ジメチルアンモニウムイオン、ギ酸及びギ酸イオン以外の有機物及び／又は無機物を含んでいても良い。
【００１２】
本発明の処理方法においては、上記廃水を、ジメチルアミン、ジメチルアンモニウムイオン、ギ酸及びギ酸イオンの合計濃度を０．０５重量％以下となるよう調整することが必要である。この調整によって、続く抽出操作による廃水の浄化効率を上げることが可能になるのである。
【００１３】
ジメチルアミン、ジメチルアンモニウムイオン、ギ酸及びギ酸イオンの合計濃度を予め０．０５重量％以下となるよう調整するには、既知の種々の方法を用いることができるが、該廃水を陽イオン交換樹脂及び／又は陰イオン交換樹脂で処理することによってジメチルアミン、ジメチルアンモニウムイオン、ギ酸及びギ酸イオンを廃水より除去する方法が特に好ましい。
【００１４】
次いで、上記のようにして調整された廃水を、抽出処理して廃水を浄化するとともにＤＭＦを回収する。抽出処理に用いる抽出剤としては、水不溶の有機溶媒ならばいずれも使用できるが、有機酸エステル、ケトン、有機ハロゲン化物からなる群から選ばれた少なくとも一種の有機溶媒を使用することが好ましい。
【００１５】
ここで、抽出処理を行うための抽出装置としては、一般的に抽出処理に用いられる形式、例えばミキサーセトラー型、多孔板型、充填塔型、バッフル型、振動多孔板型、撹拌混合型等をいずれも採用することができる。また回分式、連続式いずれも採用することができる。
【００１６】
また、１回の抽出操作では廃水が環境上の観点から要求されるＣＯＤ及び全窒素濃度までに低減できなかった場合は、適宜抽出操作を繰り返せばよい。
【００１７】
本発明の処理方法における抽出処理に際しての抽出剤の使用量、抽出温度、抽出圧力等は特に制限はなく、浄化効率及びコストを考慮して適宜決定すれば良い。
【００１８】
上記の抽出処理を行い、環境上の観点から決定されるＣＯＤ及び全窒素濃度以下に浄化された処理済み液は、そのまま工程外に排出することができる。
【００１９】
本発明においては、廃水中に含まれていたＤＭＦは抽出処理により抽出剤中に移動するが、このＤＭＦを含む抽出剤からＤＭＦのみを回収するには、例えば蒸留のような既知の方法で可能である。
【００２０】
以下、図面をもって本発明の処理方法の一実施態様を具体的に説明するが本発明はこれにより何等限定を受けるものでは無い。
図１は本発明の処理方法の流れを模式的に示した概略図である。
まず、処理すべき廃水をポンプ（図中１）により送液して陰イオン交換樹脂を充填したジメチルアミン除去槽（図中２）に導入する。次いで陰イオン交換樹脂を充填したギ酸除去槽（図中３）に通じることにより、ジメチルアミン、ジメチルアンモニウムイオン、ギ酸及びギ酸イオンの合計濃度を予め０．０５重量％となるよう調整された廃水を得る。
【００２１】
続いて調整した廃水をポンプ（図中４）により抽出装置（図中５）に導入し、他方、抽出剤を抽出剤タンク（図中１２）からポンプ（図中１３）により（図中５）に供給する。抽出装置（図中５）内部にて廃水と抽出剤とを向流接触させて、廃水を浄化するとともにＤＭＦを抽出剤中に抽出する。
【００２２】
抽出装置（図中５）から抜き出したＤＭＦを含む抽出剤はポンプ（図中６）によりＤＭＦ回収塔（図中７）に送り、抽出剤とＤＭＦとを蒸留分離する。ＤＭＦはＤＭＦ回収塔（図中７）の上部より抜き出され、冷却器（図中８）で凝縮させた後、回収ＤＭＦとして再利用する。一方、抽出剤は回収塔（図中７）の下部より抜き出され、ポンプ（図中９）により冷却器（図中１０）を経由して抽出剤タンク（図中１２）に戻し循環使用する。
一方抽出装置（図中５）から抜き出した浄化された廃水は、ポンプ（図中１１）を経由して排出する。
【００２３】
【実施例】
以下、実施例により本発明の内容をさらに具体的に説明するが本発明はこれにより何等限定を受けるものではない。なお、実施例中の各値は以下の方法に従って求めた。
１）ＣＯＤ（化学的酸素要求量）：
常法に従い、過マンガン酸カリウム酸化滴定法によって求めた。
２）ＤＭＦ濃度及びジメチルアミン濃度：
常法に従って、ガスクロマトグラフィー法（装置：ジーエルサイエンス株式会社製ＧＣ−３８０、カラム：ＴＣ−１７０１）によって求めた。
３）ギ酸濃度：
常法に従って、イオンクロマトグラフィー法（装置：株式会社日立製作所製Ｌ−５０３０）によって求めた。
４）全窒素：
常法に従って、自動窒素測定装置（装置：三菱化学株式会社製ＴＮ−１１０微量全窒素分析装置）によって求めた。
【００２４】
［実施例１］
Ｎ，Ｎ―ジメチルホルムアミド５．０重量％、ジメチルアミン１．０重量％、ギ酸１．０重量％を含む廃水（Ａ）１２０ｇを、陽イオン交換樹脂（ＤＯＷＥＸ５０Ｗ×８ Ｈ型）４０ｇに投入し２時間静置した。静置処理後、廃水を陽イオン交換樹脂と分離した。この処理廃水を廃水（Ｂ）とする。
【００２５】
次いで、廃水（Ｂ）９０ｇを陰イオン交換樹脂（Ａｍｂｅｒｌｉｔｅ ＩＲ−２１０Ｂ ＯＨ型）３０ｇに投入し、２時間静置した。静置処理後、廃水を陽イオン交換樹脂と分離した。この処理廃水を廃水（Ｃ）とする。
【００２６】
廃水（Ｃ）のＮ，Ｎ−ジメチルホルムアミドは３．６重量％、ジメチルアミンは０．０１重量％未満、ギ酸は０．０２重量％であり、ジメチルアミン、ジメチルアンモニウムイオン、ギ酸及びギ酸イオンの合計濃度（以下ＤＭＡ＋ＦＡ濃度と略記することがある。）は０．０２重量％であった。
【００２７】
次いで、廃水（Ｃ）のうち５０ｇを分液漏斗に投入し、続いて抽出剤として塩化メチレン（試薬特級）１００ｇを該分液漏斗に投入し、充分振とう後静置し塩化メチレン層を分離した。残った水層に対して上記の塩化メチレン抽出操作をさらに４回繰り返し、計５回の抽出操作後の、水層中のＣＯＤ及び全窒素分を測定した。同様にして、廃水（Ｃ）に対し、抽出剤として塩化メチレンから代えて、表１記載の抽出剤（安息香酸メチル、２−ヘプタノン）を使用して抽出処理を行った。以上の結果を表１に示す。
【００２８】
［実施例２］
実施例１において、陽イオン交換樹脂及び陰イオン交換樹脂に投入し静置する時間を各２時間から変更し、各１時間としたこと以外は、同様の操作を行った。抽出処理を実施する前のイオン交換樹脂処理廃水（Ｃ）のＮ，Ｎ−ジメチルホルムアミドは４．０重量％、ジメチルアミンは０．０２重量％、ギ酸は０．０２重量％であり、ＤＭＡ＋ＦＡ濃度は０．０４重量％であった。結果を表１に示した。
【００２９】
［比較例１］
実施例１において、イオン交換樹脂で処理をする前の廃水（Ａ）をそのまま抽出処理に供したこと以外は同様の操作を行った。結果を表１に示す。充分な廃水の浄化効果を得ることができなかった。
【００３０】
［比較例２］
実施例１において、陽イオン交換樹脂及び陰イオン交換樹脂に投入し静置する時間を各２時間から変更し、各０．５時間としたこと以外は、同様の操作を行った。廃水（Ｃ）のＮ，Ｎ−ジメチルホルムアミドは４．５重量％、ジメチルアミンは０．２２重量％、ギ酸は０．２６重量％であり、ＤＭＡ＋ＦＡ濃度は０．４９重量％であった。結果を表１に示す。
【００３１】
【表１】
【発明の効果】
本発明によれば、Ｎ，Ｎ−ジメチルホルムアミド含有廃水を溶剤抽出法にて処理して、該廃水のＣＯＤ及び全窒素濃度を効果的に低減させる方法を提供することができる。
【図面の簡単な説明】
【図１】本発明を実施するための一態様を模式的に示したフロー図である。
【符号の説明】
１ 排水送液ポンプ
２ ジメチルアミン除去槽
３ ギ酸除去槽
４ 廃水抽出塔送液ポンプ
５ 抽出装置
６ ＤＭＦ回収塔送液ポンプ
７ ＤＭＦ回収塔
８ 冷却器
９ 抽出剤抜き出しポンプ
１０ 冷却器
１１ 浄化廃水送液ポンプ
１２ 抽出剤タンク
１３ 抽出剤ポンプ[0001]
BACKGROUND OF THE INVENTION
The present invention treats waste water containing N, N-dimethylformamide, which is widely used in solvents, reaction solvents, etc., recovers N, N-dimethylformamide, and chemically oxygenates waste water containing N, N-dimethylformamide. The present invention relates to a processing method for reducing the required amount and the total nitrogen concentration .
[0002]
[Prior art]
N, N-dimethylformamide (hereinafter sometimes abbreviated as DMF) is widely used industrially as an organic solvent soluble in water. In a process in which DMF is manufactured or used, DMF may be contained in the discharged wastewater. However, wastewater containing DMF contains chemical oxygen demand (hereinafter sometimes abbreviated as COD) and total nitrogen. Since the concentration is high, it is necessary to perform some purification treatment from the viewpoint of preventing environmental pollution.
[0003]
As a general wastewater purification treatment method, there is an activated sludge treatment method that causes microorganisms to decompose, but it is extremely sensitive to changes in DMF concentration and difficult to manage, and DMF is recovered and reused. There is a disadvantage that can not be.
[0004]
In addition, there is a treatment method in which wastewater containing DMF is burned as it is, but generally the DMF concentration in the wastewater is low, and it takes much energy to evaporate water in the combustion process, and it is not economical, and DMF is recovered. This is not an advantageous method.
[0005]
Further, a method is known in which DMF is recovered at the same time that organic substances are removed from wastewater by distilling off water. Although this method can recover DMF, it still requires a great deal of energy to evaporate water and is not economical.
[0006]
As a method for solving the problems of the above-mentioned technology, DMF in wastewater is extracted using a water-insoluble extractant, and then the wastewater is purified and distilled by separating the extractant and DMF by distillation. JP-A-53-77006 discloses a method for extracting DMF in an aqueous solution with a substituted phenol, and JP-A-55-141450 discloses pyrrole and aniline. A method for extracting alkylamide using pentanol or the like as an extractant is disclosed. However, there has been a problem that even if these extraction methods are used and purification processing by extraction is repeated, the purification cannot be sufficiently performed.
[0007]
[Problems to be solved by the invention]
The object of the present invention is to solve the above-mentioned problems of the prior art and to treat N, N-dimethylformamide-containing wastewater by a solvent extraction method to effectively reduce the COD and total nitrogen concentration of the wastewater. It is to provide a method of making it happen.
[0008]
[Means for Solving the Problems]
As a result of intensive studies in view of the above-described prior art, the present inventors have produced dimethylamine, dimethylammonium ions, formic acid and formate ions in the wastewater by hydrolysis of N, N-dimethylformamide, It was found that their presence prevented the reduction of COD and total nitrogen concentration, and the present invention was completed.
[0009]
That is, the object of the present invention is to
Process for reducing chemical oxygen demand and total nitrogen concentration of wastewater containing at least one organic compound selected from the group consisting of dimethylamine, dimethylammonium ion, formic acid and formate ion and N, N-dimethylformamide The organic compound concentration in the wastewater is adjusted to be 0.05% by weight or less in advance, and then solvent extraction is performed to remove N, N-dimethylformamide from the wastewater. , N, N-dimethylformamide containing wastewater can be achieved by a treatment method that reduces chemical oxygen demand and total nitrogen concentration .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
The wastewater to be treated to which the treatment method of the present invention is applied contains DMF and dimethylamine and / or formic acid. Here, dimethylamine may exist in the form of dimethylammonium ions in the wastewater, and formic acid in the form of formate ions in the wastewater.
[0011]
The treatment method of the present invention may be applied to waste water in which the total concentration of dimethylamine, dimethylammonium ion, formic acid and formate ion exceeds 0.05% by weight, and the concentration is 0.05% by weight or less. Need not use the processing method of the present invention. The wastewater to be treated may contain organic substances and / or inorganic substances other than DMF, dimethylamine, dimethylammonium ions, formic acid and formate ions.
[0012]
In the treatment method of the present invention, it is necessary to adjust the waste water so that the total concentration of dimethylamine, dimethylammonium ion, formic acid and formate ion is 0.05% by weight or less. By this adjustment, it becomes possible to increase the purification efficiency of the wastewater by the subsequent extraction operation.
[0013]
In order to adjust the total concentration of dimethylamine, dimethylammonium ion, formic acid and formate ion to 0.05% by weight or less in advance, various known methods can be used. A method in which dimethylamine, dimethylammonium ions, formic acid and formate ions are removed from wastewater by treatment with an / ion exchange resin is particularly preferred.
[0014]
Next, the wastewater adjusted as described above is extracted to purify the wastewater and recover DMF. As the extractant used in the extraction treatment, any water-insoluble organic solvent can be used, but it is preferable to use at least one organic solvent selected from the group consisting of organic acid esters, ketones, and organic halides.
[0015]
Here, as an extraction apparatus for performing the extraction process, a type generally used for the extraction process, for example, a mixer-settler type, a perforated plate type, a packed tower type, a baffle type, a vibrating perforated plate type, a stirring and mixing type, etc. Either can be adopted. Both batch type and continuous type can be adopted.
[0016]
In addition, if the wastewater cannot be reduced to the COD and total nitrogen concentrations required from an environmental viewpoint in one extraction operation, the extraction operation may be repeated as appropriate.
[0017]
There are no particular restrictions on the amount of extraction agent used, the extraction temperature, the extraction pressure, etc. during the extraction process in the treatment method of the present invention, and it may be determined as appropriate in consideration of purification efficiency and cost.
[0018]
The extracted liquid that has been subjected to the above-described extraction process and purified to be equal to or less than the COD and total nitrogen concentration determined from an environmental point of view can be directly discharged out of the process.
[0019]
In the present invention, DMF contained in the wastewater is transferred into the extractant by the extraction process, but only DMF can be recovered from the extractant containing DMF by a known method such as distillation. It is.
[0020]
Hereinafter, although one embodiment of the processing method of the present invention will be described in detail with reference to the drawings, the present invention is not limited thereto.
FIG. 1 is a schematic view schematically showing the flow of the processing method of the present invention.
First, waste water to be treated is fed by a pump (1 in the figure) and introduced into a dimethylamine removal tank (2 in the figure) filled with an anion exchange resin. Next, by passing through a formic acid removal tank (3 in the figure) filled with an anion exchange resin, waste water whose total concentration of dimethylamine, dimethylammonium ion, formic acid and formate ion was adjusted to 0.05% by weight in advance was removed. obtain.
[0021]
Subsequently, the adjusted waste water is introduced into the extraction device (5 in the figure) by the pump (4 in the figure), while the extractant is extracted from the extractant tank (12 in the figure) by the pump (13 in the figure (5 in the figure)). To supply. The wastewater and the extractant are brought into countercurrent contact with each other inside the extraction device (5 in the figure) to purify the wastewater and extract DMF into the extractant.
[0022]
The extractant containing DMF extracted from the extractor (5 in the figure) is sent to the DMF recovery tower (7 in the figure) by a pump (6 in the figure), and the extractant and DMF are separated by distillation. DMF is extracted from the upper part of the DMF recovery tower (7 in the figure), condensed in a cooler (8 in the figure), and then reused as recovered DMF. On the other hand, the extractant is extracted from the lower part of the recovery tower (7 in the figure), and returned to the extractant tank (12 in the figure) via the cooler (9 in the figure) by the pump (9 in the figure) for circulation. .
On the other hand, the purified waste water extracted from the extraction device (5 in the figure) is discharged via a pump (11 in the figure).
[0023]
【Example】
Hereinafter, the contents of the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In addition, each value in an Example was calculated | required according to the following method.
1) COD (chemical oxygen demand):
According to a conventional method, it was determined by a potassium permanganate oxidation titration method.
2) DMF concentration and dimethylamine concentration:
According to a conventional method, it was determined by a gas chromatography method (apparatus: GC-380 manufactured by GL Sciences Inc., column: TC-1701).
3) Formic acid concentration:
According to a conventional method, it was determined by an ion chromatography method (apparatus: L-5030 manufactured by Hitachi, Ltd.).
4) Total nitrogen:
According to a conventional method, it was determined by an automatic nitrogen measuring device (device: TN-110 trace total nitrogen analyzer manufactured by Mitsubishi Chemical Corporation).
[0024]
[Example 1]
120 g of waste water (A) containing 5.0% by weight of N, N-dimethylformamide, 1.0% by weight of dimethylamine and 1.0% by weight of formic acid was added to 40 g of cation exchange resin (DOWEX 50W × 8H type). Let stand for 2 hours. After the standing treatment, the waste water was separated from the cation exchange resin. This treated wastewater is defined as wastewater (B).
[0025]
Next, 90 g of waste water (B) was added to 30 g of an anion exchange resin (Amberlite IR-210B OH type) and allowed to stand for 2 hours. After the standing treatment, the waste water was separated from the cation exchange resin. This treated wastewater is defined as wastewater (C).
[0026]
The waste water (C) is 3.6% by weight of N, N-dimethylformamide, less than 0.01% by weight of dimethylamine and 0.02% by weight of formic acid, and contains dimethylamine, dimethylammonium ion, formic acid and formate ion. The total concentration (hereinafter sometimes abbreviated as DMA + FA concentration) was 0.02% by weight.
[0027]
Next, 50 g of waste water (C) was put into a separatory funnel, and then 100 g of methylene chloride (special grade reagent) as an extractant was put into the separatory funnel. After sufficiently shaking, the methylene chloride layer was separated. did. The above methylene chloride extraction operation was further repeated four times for the remaining aqueous layer, and the COD and total nitrogen content in the aqueous layer after a total of five extraction operations were measured. Similarly, the waste water (C) was subjected to an extraction treatment using the extractant (methyl benzoate, 2-heptanone) shown in Table 1 instead of methylene chloride as the extractant. The results are shown in Table 1.
[0028]
[Example 2]
In Example 1, the same operation was performed except that the time for charging and leaving the cation exchange resin and the anion exchange resin was changed from 2 hours to 1 hour. N, N-dimethylformamide is 4.0% by weight, dimethylamine is 0.02% by weight, formic acid is 0.02% by weight, and DMA + FA concentration in the waste water (C) treated with the ion exchange resin before the extraction treatment Was 0.04% by weight. The results are shown in Table 1.
[0029]
[Comparative Example 1]
In Example 1, the same operation was performed except that the waste water (A) before being treated with the ion exchange resin was directly subjected to the extraction treatment. The results are shown in Table 1. Sufficient wastewater purification effect could not be obtained.
[0030]
[Comparative Example 2]
In Example 1, the same operation was performed except that the time for putting into and leaving the cation exchange resin and the anion exchange resin was changed from 2 hours to 0.5 hours. In the waste water (C), N, N-dimethylformamide was 4.5% by weight, dimethylamine was 0.22% by weight, formic acid was 0.26% by weight, and the DMA + FA concentration was 0.49% by weight. The results are shown in Table 1.
[0031]
[Table 1]
【The invention's effect】
According to the present invention, it is possible to provide a method for treating N, N-dimethylformamide-containing wastewater by a solvent extraction method to effectively reduce the COD and total nitrogen concentration of the wastewater.
[Brief description of the drawings]
FIG. 1 is a flowchart schematically showing an embodiment for carrying out the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wastewater feed pump 2 Dimethylamine removal tank 3 Formic acid removal tank 4 Waste water extraction tower
Claims (5)
該廃水中の有機化合物濃度を予め０．０５重量％以下となるように調整した後、溶媒抽出を実施して、廃水からＮ，Ｎ−ジメチルホルムアミドを除去することを特徴とする、Ｎ，Ｎ−ジメチルホルムアミド含有廃水の化学的酸素要求量と全窒素濃度とを低減させる処理方法。 Process for reducing chemical oxygen demand and total nitrogen concentration of wastewater containing at least one organic compound selected from the group consisting of dimethylamine, dimethylammonium ion, formic acid and formate ion and N, N-dimethylformamide Because
N, N-dimethylformamide is characterized by removing N, N-dimethylformamide from waste water by adjusting the organic compound concentration in the waste water to 0.05 wt% or less in advance and then performing solvent extraction. -A treatment method for reducing chemical oxygen demand and total nitrogen concentration of dimethylformamide-containing wastewater.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002153572A JP3902069B2 (en) | 2002-05-28 | 2002-05-28 | Method for treating wastewater containing N, N-dimethylformamide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002153572A JP3902069B2 (en) | 2002-05-28 | 2002-05-28 | Method for treating wastewater containing N, N-dimethylformamide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003340441A JP2003340441A (en) | 2003-12-02 |
| JP3902069B2 true JP3902069B2 (en) | 2007-04-04 |
Family
ID=29770579
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002153572A Expired - Fee Related JP3902069B2 (en) | 2002-05-28 | 2002-05-28 | Method for treating wastewater containing N, N-dimethylformamide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3902069B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10370398B2 (en) | 2016-06-23 | 2019-08-06 | Tate & Lyle Technology Limited | Liquid-liquid extraction of DMF |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104003566B (en) * | 2014-05-28 | 2015-08-05 | 东莞市灿森新材料有限公司 | The recovery method of many components waste liquid in high-performance aramid fiber fibrid production process |
| CN104163526B (en) * | 2014-08-28 | 2016-07-06 | 清华大学 | A kind of pH that regulates strengthens the method for nitrosamine precursor in ion exchange removal water |
| CN108793553A (en) * | 2018-06-09 | 2018-11-13 | 石家庄市绿丰化工有限公司 | A kind of method of DMF Sewage treatments |
| CN111054203B (en) * | 2019-12-30 | 2023-12-22 | 陕西鼓风机（集团）有限公司 | Tail gas treatment method and system for DMF wastewater |
| CN111470997A (en) * | 2020-04-26 | 2020-07-31 | 安庆市鑫祥瑞环保科技有限公司 | Method for recovering DMF waste liquid |
| CN113636705A (en) * | 2021-09-10 | 2021-11-12 | 江苏大彭环保科技有限公司 | Method for controlling total nitrogen of waste water containing DMF (dimethyl formamide) |
-
2002
- 2002-05-28 JP JP2002153572A patent/JP3902069B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10370398B2 (en) | 2016-06-23 | 2019-08-06 | Tate & Lyle Technology Limited | Liquid-liquid extraction of DMF |
| US10899783B2 (en) | 2016-06-23 | 2021-01-26 | Tate & Lyle Technology Limited | Liquid-liquid extraction of DMF |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2003340441A (en) | 2003-12-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4611378B2 (en) | Extraction of phenol-containing effluent stream | |
| CN109911918A (en) | The resource utilization method of industrial mixed salt containing organic solvent | |
| CA1316942C (en) | Process for extracting and disposing of nitrophenolic by-products | |
| JP3902069B2 (en) | Method for treating wastewater containing N, N-dimethylformamide | |
| US4374283A (en) | Purification of aqueous effluent streams containing BPA and phenol | |
| EP0396790A1 (en) | Process for the removal of nitrate and organic pollutants from effluents | |
| JPH11347536A (en) | Method for treating wastewater containing phenols | |
| CN103014338A (en) | Method for processing poor organic phase after solvent extraction indium extracting | |
| CN102417265B (en) | Method for effectively removing organic matters in wastewater from nitrochlorobenzene production | |
| KR100899777B1 (en) | Enhancement of the recovery efficiency in the waste photoresist stripper recycling process | |
| KR100367356B1 (en) | Method for Purifying Liquid Medium by Extraction | |
| CN109368859B (en) | Zero-discharge treatment process for fluoride-applying wastewater in steroid drug production | |
| JP3692497B2 (en) | Method for recovering dimethyl sulfoxide | |
| JP2004043434A (en) | Method for refining high-purity dimethyl sulfoxide and mixture of dimethyl sulfoxide with amines | |
| CN102295380A (en) | Processing and recovering method of aromatic nitro-compound wastewater | |
| CN1162335C (en) | Process of recovering organic acid from waste alkali liquor | |
| KR100433826B1 (en) | Solvent recovery facility by the combination of extraction and distillation | |
| KR20090083119A (en) | Recovery of acid from lcd mixed waste acid | |
| JPH10249330A (en) | Treatment of boron-containing waste water | |
| WO2022239847A1 (en) | Method for collecting carboxylic acid | |
| JP2003047953A (en) | Method for recovering solvent in wastewater | |
| KR102252883B1 (en) | Method for purifying organic acids | |
| CN111943297A (en) | Method for resourceful treatment of high-salinity high-organic wastewater | |
| JP3966934B2 (en) | Carbon monoxide gas purification method | |
| KR100243061B1 (en) | A recycling method of low boiling point organic matter in waste water |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A711 | Notification of change in applicant |
Free format text: JAPANESE INTERMEDIATE CODE: A712 Effective date: 20041028 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20041119 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20061002 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20061010 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20061113 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20061205 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20061227 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100112 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110112 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120112 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120112 Year of fee payment: 5 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120112 Year of fee payment: 5 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130112 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130112 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140112 Year of fee payment: 7 |
|
| LAPS | Cancellation because of no payment of annual fees |