JPH05329486A - Method for treating waste water of alkali reduction treatment for polyester fiber - Google Patents

Method for treating waste water of alkali reduction treatment for polyester fiber

Info

Publication number
JPH05329486A
JPH05329486A JP13859492A JP13859492A JPH05329486A JP H05329486 A JPH05329486 A JP H05329486A JP 13859492 A JP13859492 A JP 13859492A JP 13859492 A JP13859492 A JP 13859492A JP H05329486 A JPH05329486 A JP H05329486A
Authority
JP
Japan
Prior art keywords
polyester fiber
terephthalate
waste liquid
earth metal
waste water
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.)
Withdrawn
Application number
JP13859492A
Other languages
Japanese (ja)
Inventor
Kenji Maki
健治 真木
Akio Takeuchi
昭男 竹内
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Asahi Chemical Industry Co Ltd
Original Assignee
Asahi Chemical Industry Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Asahi Chemical Industry Co Ltd filed Critical Asahi Chemical Industry Co Ltd
Priority to JP13859492A priority Critical patent/JPH05329486A/en
Publication of JPH05329486A publication Critical patent/JPH05329486A/en
Withdrawn legal-status Critical Current

Links

Abstract

PURPOSE:To provide a method for recovering a solid matter low in water content easily and at high yield, and easy in dumping and little in the damage of an incinerator in the case of incineration. CONSTITUTION:In the case of treating the waste water of the alkali reduction treatment of polyester fiber, the waste water is allowed to react with alkaline earth metal oxide at pH7-14 to deposite as alkali earth metal terephthalate and is separated into solid and liquid.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明はポリエステル繊維のアル
カリ減量加工廃液を処理する方法に関するものであり、
詳しくは、ポリエステル繊維のアルカリ減量加工工程か
らの廃液中より苛性ソーダ、テレフタル酸ジアルカリ、
エチレングリコ−ル等を処理する方法に関するものであ
る。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating waste liquid of alkaline reduction processing of polyester fiber,
Specifically, from the waste solution from the alkali weight reduction process of polyester fiber, caustic soda, dialkali terephthalate,
The present invention relates to a method for treating ethylene glycol and the like.

【0002】[0002]

【従来の技術】ポリエステル繊維は通常、繊維の風合い
を改善するため、ポリエステルの一部を加水分解する処
理が施されている。この処理は、ポリエステル繊維を苛
性アルカリ水溶液と接触させることにより実施され、い
わゆる、ポリエステル繊維のアルカリ減量加工と呼ばれ
ている。この工程から排出される廃液は通常、pH10
〜14の苛性アルカリ水溶液であるが、その液中には加
水分解で生成したテレフタル酸ジアルカリ塩及びエチレ
ングリコ−ルが含まれている。この廃液は、アルカリ性
なので、通常は、pH約7に中和して、生物化学的活性
汚泥等の排水処理設備で処理されているのが現状であ
る。また、テレフタル酸ジアルカリは、COD値が大で
あるため、硫酸等を用いてテレフタル酸を酸析し、濾過
してテレフタル酸を回収する方法も採用されている。
2. Description of the Related Art Polyester fibers are usually treated to hydrolyze a part of the polyester in order to improve the texture of the fibers. This treatment is carried out by bringing the polyester fiber into contact with a caustic aqueous solution, which is called so-called alkali weight reduction processing of the polyester fiber. The waste liquid discharged from this process usually has a pH of 10
It is a caustic aqueous solution of about 14 but the solution contains diallyzed terephthalic acid salt and ethylene glycol produced by hydrolysis. Since this waste liquid is alkaline, it is currently neutralized to a pH of about 7 and treated in a wastewater treatment facility such as biochemical activated sludge. Further, since dialkali terephthalate has a large COD value, a method of acidifying terephthalic acid with sulfuric acid or the like and recovering it by filtration is also adopted.

【0003】しかし、回収されたテレフタル酸には硫酸
ナトリウム及び硫酸が多く含まれており、pHは、2〜
3の値を示している。このテレフタル酸をジメチルテレ
フタレ−ト製造の原料として利用することを考えた場
合、テレフタル酸の精製に多くの労力及びコストがかさ
むことになる。また、酸析、濾過後のテレフタル酸をそ
のまま焼却処理を施す場合は、焼却時に焼却炉が損傷す
る等の問題があった。また、テレフタル酸化合物を分離
する技術としては、電気透析により、テレフタル酸ジア
ルカリを濃縮することが試みられている(特開昭60−
216884号公報)が、濃縮後pH約7に調整しても
テレフタル酸ジアルカリは溶解したままであるため、分
離できないという問題があった。
However, the recovered terephthalic acid contains a large amount of sodium sulfate and sulfuric acid and has a pH of 2 to 2.
A value of 3 is shown. Considering the use of this terephthalic acid as a raw material for the production of dimethyl terephthalate, a lot of labor and cost are required for refining terephthalic acid. Further, when terephthalic acid after acid precipitation and filtration is directly incinerated, there is a problem that the incinerator is damaged during incineration. As a technique for separating terephthalic acid compounds, it has been attempted to concentrate dialkali terephthalate by electrodialysis (JP-A-60-
No. 216884), there is a problem in that the dialkali terephthalate remains dissolved even if the pH is adjusted to about 7 after concentration, so that it cannot be separated.

【0004】[0004]

【発明が解決しようとする課題】本発明の目的は、ポリ
エステル繊維のアメカリ減量加工廃液中に含まれるテレ
フタル酸ジアルカリを水分率が少なく廃棄が容易であ
り、焼却処分を施す場合でも、焼却処理時に焼却炉を損
傷させることのないアルカリ減量加工廃液を処理する方
法を提供することにある。
DISCLOSURE OF THE INVENTION An object of the present invention is to reduce the moisture content of dialkali terephthalate contained in the waste liquid for the mechanical reduction of polyester fiber, which has a low water content and can be easily discarded. It is an object of the present invention to provide a method for treating an alkali weight loss processing waste liquid without damaging an incinerator.

【0005】[0005]

【課題を解決するための手段】上記問題を解決するため
に、本発明者らは、苛性ソ−タ及びテレフタル酸ジアル
カリの新たな処理方法を鋭意検討した結果、本発明を完
成した。本発明は、ポリエステル繊維のアルカリ減量加
工工程の廃液を、pH7〜14に於て、アルカリ土類金
属水酸化物と反応させ、テレフタル酸アルカリ土類金属
塩として析出せしめ、次いで固液分離を行うことを特徴
とするポリエステル繊維のアルカリ減量加工廃液を処理
する方法である。
In order to solve the above problems, the present inventors have conducted extensive studies on a new treatment method for caustic soda and dialkali terephthalate, and have completed the present invention. In the present invention, the waste liquid of the alkaline weight reduction processing step of polyester fiber is reacted with an alkaline earth metal hydroxide at pH 7-14 to precipitate it as an alkaline earth metal terephthalate salt, and then solid-liquid separation is performed. A method for treating an alkali weight loss processing waste liquid of polyester fiber, which is characterized by the above.

【0006】本発明で対象となるテレフタル酸のアルカ
リ塩を含む廃液としては、通常、ポリエステル織物のア
ルカリ減量加工工程から排出されるpH10〜14程度
の苛性ソ−ダまたは苛性カリなどの苛性アルカリ性水溶
液である。この廃液中にはテレフタル酸ジアルカリ塩が
テレフタル酸として0.5〜10重量%及びこのテレフ
タル酸と略等モルのエチレングリコ−ルを主成分として
含んでいる。本発明では、この廃液に対して直接アルカ
リ土類金属水酸化物あるいはその水溶液またはスラリ−
を加えテレフタル酸アルカリ土類金属塩の結晶を含んだ
スラリ−と成し、そのまま、もしくは濃縮し次の中和処
理を行う。
The waste liquid containing an alkali salt of terephthalic acid, which is the object of the present invention, is usually a caustic soda having a pH of about 10 to 14 or a caustic alkaline aqueous solution such as caustic potash, which is discharged from the alkaline weight reduction processing step of polyester fabric. is there. The waste liquid contains 0.5 to 10% by weight of terephthalic acid dialkali salt as terephthalic acid and ethylene glycol in an approximately equimolar amount to the terephthalic acid as main components. In the present invention, an alkaline earth metal hydroxide or its aqueous solution or slurry is directly added to this waste liquid.
Is added to form a slurry containing crystals of an alkaline earth metal terephthalate salt, and the slurry is left as it is or concentrated to perform the next neutralization treatment.

【0007】本発明で使用するアルカリ土類金属水酸化
物としては、水酸化カルシウム、水酸化バリウム等が挙
げられる。これらのアルカリ土類金属水酸化物によりテ
レフタル酸アルカリ土類金属塩結晶を析出せしめたスラ
リ−状の溶液をそのまま、または上澄液を約80%分離
し、無機酸又は有機酸を使用してpHを5〜9に調整す
る。無機酸としては、硫酸、塩酸、硝酸、燐酸等が挙げ
られる。有機酸としては、酢酸、酒石酸、クエン酸、ポ
リアクリル酸等が挙げられる。これらの酸を用いてテレ
フタル酸アルカリ土類金属塩スラリ−のpH調節を行
い、フィルタ−プレス或は、セントル型の遠心分離機を
用いて、ケ−キと濾液に分離する。炉液中の苛性ソ−ダ
は、電気透析や電気分解により精製するすることができ
る。
Examples of the alkaline earth metal hydroxide used in the present invention include calcium hydroxide and barium hydroxide. A slurry-like solution in which terephthalic acid alkaline earth metal salt crystals are precipitated by these alkaline earth metal hydroxides is used as it is, or about 80% of the supernatant is separated, and an inorganic acid or an organic acid is used. Adjust pH to 5-9. Examples of the inorganic acid include sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid and the like. Examples of the organic acid include acetic acid, tartaric acid, citric acid, polyacrylic acid and the like. The pH of the alkaline earth metal terephthalate salt slurry is adjusted using these acids, and the cake and the filtrate are separated using a filter press or a centrifuge. The caustic soda in the furnace liquid can be purified by electrodialysis or electrolysis.

【0008】アルカリ土類金属水酸化物として水酸化カ
ルシウムを使用する場合を例にとり説明すると、廃液中
のテレフタル酸ジアルカリは水酸化カルシウムと反応し
てテレフタル酸カルシウムの白色沈澱を生成する。溶液
の方には、苛性ソ−ダが新たに生成し、より高濃度とな
った苛性ソ−ダの溶液となる。このスラリ−状溶液を濾
過し、テレフタル酸カルシウムと濃厚苛性ソ−ダ溶液に
分離する。したがって、苛性ソ−ダの回収を主体に考え
る場合は、テレフタル酸ジアルカリと水酸化カルシウム
が反応したスラリ−を直接濾過して高濃度の苛性ソ−ダ
を含んだ濾液を得ることができる。この苛性ソ−ダはイ
オン交換膜による電気透析によって、高収率で精製苛性
ソ−ダとして回収することができる。
The case of using calcium hydroxide as the alkaline earth metal hydroxide will be described as an example. The dialkali terephthalate in the waste liquid reacts with the calcium hydroxide to form a white precipitate of calcium terephthalate. In the solution, caustic soda is newly generated, and becomes a solution of caustic soda having a higher concentration. The slurry solution is filtered and separated into calcium terephthalate and concentrated caustic soda solution. Therefore, when the recovery of caustic soda is mainly considered, the slurry in which dialkali terephthalate and calcium hydroxide are reacted can be directly filtered to obtain a filtrate containing a high concentration of caustic soda. This caustic soda can be recovered in high yield as purified caustic soda by electrodialysis using an ion exchange membrane.

【0009】[0009]

【実施例】次に、本発明を実施例により具体的に説明す
る。
EXAMPLES Next, the present invention will be specifically described by way of examples.

【0010】[0010]

【実施例1】ポリエステル繊維をバッチ方式でアルカリ
減量加工を施した廃液についての処理を下記の通り行っ
た。廃液の苛性ソ−ダの濃度は、1.08モル/L、テ
レフタル酸ジナトリウムの濃度は、0.16モル/Lで
あった(エチレングリコ−ルの濃度は、0.18モル/
L)。この廃液に対して水酸化カルシウムスラリ−をテ
レフタル酸と当モルになるように加え撹拌し、0.16
モル/Lのテレフタル酸カルシウムの白色沈澱を得た。
このスラリ−状溶液を濾過し、テレフタル酸カルシウム
結晶ケ−キ及び苛性ソ−ダ1.4モル/Lの濾液をえ
た。テレフタル酸カルシウム結晶ケ−キは、10倍量の
水に分散させ、クエン酸にてpH8に中和し再び濾過し
た。このテレフタル酸カルシウム結晶ケ−キは、約55
%の水分を含んでいる。このケ−キは、天日に晒して乾
燥して、燃料として用いた。苛性ソ−ダ1.4モル/L
を含んだ濾液は、フッソ系カチオン交換膜をつかって電
気透析を行い、90%の回収率で精製苛性ソ−ダを得
た。
Example 1 A waste liquid obtained by subjecting polyester fiber to alkali reduction processing in a batch system was treated as follows. The concentration of caustic soda in the waste liquid was 1.08 mol / L and the concentration of disodium terephthalate was 0.16 mol / L (the concentration of ethylene glycol was 0.18 mol / L).
L). Calcium hydroxide slurry was added to this waste liquid so as to be equimolar to terephthalic acid, and stirred to give 0.16
A white precipitate of mol / L calcium terephthalate was obtained.
The slurry-like solution was filtered to obtain a calcium terephthalate crystal cake and a caustic soda 1.4 mol / L filtrate. The calcium terephthalate crystal cake was dispersed in 10 times the amount of water, neutralized to pH 8 with citric acid, and filtered again. This calcium terephthalate crystal cake is about 55
Contains% moisture. The cake was exposed to the sun and dried to be used as a fuel. Caustic soda 1.4 mol / L
The filtrate containing was subjected to electrodialysis using a fluorine-based cation exchange membrane to obtain purified caustic soda with a recovery rate of 90%.

【0011】[0011]

【実施例2】ポリエステル繊維を連続式パッドスチ−ム
法でアルカリ減量加工を施した廃液について下記の処理
を行った。廃液の苛性ソ−ダの濃度は、0.24モル/
L、テレフタル酸ジナトリウムの濃度は、0.16モル
/Lであった(エチレングリコ−ルの濃度は、0.19
モル/L)。この廃液に対して水酸化バリウム水溶液を
テレフタル酸と当モルになるように加え撹拌し、0.1
6モル/Lのテレフタル酸カルシウムの白色沈澱を得
た。このスラリ−状溶液を一昼夜放置し、上澄液を80
%傾瀉し、濃縮したスラリ−を硫酸でpH8まで中和
し、次いで濾過し、テレフタル酸カルシウム結晶ケ−キ
を得た。傾瀉した上澄液は、フッソ系カチオン交換膜を
使用して電気透析を行い、92%の回収率で精製苛性ソ
−ダを得た。
Example 2 A waste liquid obtained by subjecting polyester fiber to alkali reduction processing by a continuous pad steam method was subjected to the following treatment. The concentration of caustic soda in the waste liquid is 0.24 mol /
The concentration of L and disodium terephthalate was 0.16 mol / L (the concentration of ethylene glycol was 0.19
Mol / L). An aqueous solution of barium hydroxide is added to this waste liquid so as to be equimolar to terephthalic acid and stirred,
A white precipitate of 6 mol / L calcium terephthalate was obtained. The slurry-like solution is left to stand overnight and the supernatant liquid is
The% decanted and concentrated slurry was neutralized to pH 8 with sulfuric acid and then filtered to give a calcium terephthalate crystal cake. The decanted supernatant was electrodialyzed using a fluorine-based cation exchange membrane to obtain purified caustic soda with a recovery rate of 92%.

【0012】[0012]

【実施例3、4、比較例1〜2】実施例2と同じ廃液を
用いてテレフタル酸ジナトリウムに対してアルカリ土類
金属水酸化物を反応させ、生成したスラリ−を一日放置
し、上澄みを傾瀉し、濃縮されたスラリ−を硫酸でもっ
てpH8に中和し濾過しテレフタル酸アルカリ土類金属
塩を得た。比較のため、実施例2の廃液を硫酸または塩
酸で酸析してテレフタル酸の白色沈殿物を含んだスラリ
ーを得た。その上澄液を傾瀉して濃縮し、カセイソーダ
水溶液でpH7に調節したところ、大部分が再び溶解
し、濾過分離することができなかった。これらの結果を
表1に示す。
Examples 3 and 4, Comparative Examples 1-2 Using the same waste liquid as in Example 2, disodium terephthalate was reacted with an alkaline earth metal hydroxide, and the resulting slurry was allowed to stand for one day. The supernatant was decanted and the concentrated slurry was neutralized to pH 8 with sulfuric acid and filtered to obtain an alkaline earth metal terephthalate salt. For comparison, the waste liquid of Example 2 was acidified with sulfuric acid or hydrochloric acid to obtain a slurry containing a white precipitate of terephthalic acid. When the supernatant was decanted and concentrated, and the pH was adjusted to 7 with an aqueous caustic soda solution, most of it was dissolved again and could not be separated by filtration. The results are shown in Table 1.

【0013】[0013]

【表1】 [Table 1]

【0014】本発明によると、水分率85%以下、pH
が5〜9のテレフタル酸ジアルカリ土類金属塩が高収率
で回収でき、廃棄する場合も取扱が容易であった。ま
た、5cm×10cm×1cmの耐火レンガのピ−スに
実施例3、4および比較例1〜2の塩析沈殿物および酸
析沈殿物の各5gを3cm×8cmの大きさに塗り付け
750℃の電気炉中で8Hr/日焼却、16時間放冷を
5日間繰り返し、塩析物および酸析物による焼却炉の損
傷の程度を調べた結果、本発明の場合、損傷が殆ど認め
られなかった。
According to the present invention, the water content is 85% or less, the pH is
It was possible to recover a dialkaline earth metal terephthalate salt of 5 to 9 in a high yield, and it was easy to handle even when it was discarded. Further, 5 g of each of the salted-out precipitates and acid-deposited precipitates of Examples 3 and 4 and Comparative Examples 1 and 2 was applied on a piece of 5 cm × 10 cm × 1 cm refractory brick in a size of 3 cm × 8 cm 750. Incinerating in an electric furnace at ℃ for 8 hours / day, cooling for 16 hours was repeated for 5 days, and the degree of damage to the incinerator due to salting out and acid depositing substances was examined. It was

【0015】[0015]

【発明の効果】本発明によると、ポリエステル繊維のア
ルカリ減量加工廃液からのテレフタル酸アルカリ土類金
属塩を析出、濾過することにより、廃棄が容易な低水分
率の固形物を容易に得ることができ、焼却処分わ施す場
合でも、焼却炉を損傷させることのないアルカリ減量加
工廃液の処理方法を有効に提供することができる。ま
た、ポリエステル繊維のアルカリ減量加工廃液を有効に
処理できるため、回収再利用できる部分と産業廃棄物と
する部分および排水処理設備で処理する部分に分け全体
として有用な処理する方法をも提供することができる。
EFFECTS OF THE INVENTION According to the present invention, it is possible to easily obtain a solid substance having a low water content which can be easily discarded by precipitating and filtering an alkaline earth metal terephthalate salt from a waste liquid for alkaline reduction processing of polyester fiber. Therefore, it is possible to effectively provide a method for treating an alkali weight loss processing waste liquid that does not damage the incinerator even when it is subjected to incineration disposal. Also, since it is possible to effectively treat the alkali reduction processing waste liquid of the polyester fiber, it is necessary to provide a useful treatment method as a whole by dividing it into a portion that can be recovered and reused, an industrial waste portion and a wastewater treatment facility. You can

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 ポリエステル繊維のアルカリ減量加工工
程の廃液を、pH7〜14のアルカリ性下に於て、アル
カリ土類金属水酸化物と反応させ、テレフタル酸アルカ
リ土類金属塩として析出せしめ、次いで固液分離を行う
ことを特徴とするポリエステル繊維のアルカリ減量加工
廃液を処理する方法。
1. A waste liquid from the alkaline weight reduction processing step of polyester fiber is reacted with an alkaline earth metal hydroxide under an alkaline condition of pH 7 to 14 to precipitate it as an alkaline earth metal salt of terephthalic acid, which is then solidified. A method for treating waste liquid of alkali reduction processing of polyester fiber, which comprises performing liquid separation.
JP13859492A 1992-05-29 1992-05-29 Method for treating waste water of alkali reduction treatment for polyester fiber Withdrawn JPH05329486A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP13859492A JPH05329486A (en) 1992-05-29 1992-05-29 Method for treating waste water of alkali reduction treatment for polyester fiber

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP13859492A JPH05329486A (en) 1992-05-29 1992-05-29 Method for treating waste water of alkali reduction treatment for polyester fiber

Publications (1)

Publication Number Publication Date
JPH05329486A true JPH05329486A (en) 1993-12-14

Family

ID=15225748

Family Applications (1)

Application Number Title Priority Date Filing Date
JP13859492A Withdrawn JPH05329486A (en) 1992-05-29 1992-05-29 Method for treating waste water of alkali reduction treatment for polyester fiber

Country Status (1)

Country Link
JP (1) JPH05329486A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103848521A (en) * 2014-03-17 2014-06-11 佛山市金铭机械制造有限公司 Alkali deweighting wastewater recycling device
JP2016160171A (en) * 2015-03-05 2016-09-05 株式会社豊田中央研究所 Carbon porous body and manufacturing method therefor

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103848521A (en) * 2014-03-17 2014-06-11 佛山市金铭机械制造有限公司 Alkali deweighting wastewater recycling device
JP2016160171A (en) * 2015-03-05 2016-09-05 株式会社豊田中央研究所 Carbon porous body and manufacturing method therefor

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