JP2003112917A - Method for recovering boron in waste water and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate and recover boron compounds contained in waste water and to effectively utilize these. SOLUTION: Boron in waste water is adsorbed and separated using a boron adsorption tower packed with a boron adsorbing resin, the boron adsorbing resin is then regenerated with acidic and alkaline resin regenerating aqueous solutions and the boron is desorbed from the adsorbing resin and transferred to the resin regenerating aqueous solution side to produce regenerative waste water. This regenerative waste water containing the desorbed boron is passed through an activated carbon adsorption bed to adsorb and remove impurities such as a coloring component, and boron compounds remaining in the regenerative waste water are refined, recovered and reutilized.

Description

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

【０００１】[0001]

【発明が属する技術分野】本発明は、排水中等に溶存す
るホウ素化合物を、ホウ素吸着樹脂の利用により吸着分
離し、回収する方法、及び装置に関する。TECHNICAL FIELD The present invention relates to a method and an apparatus for adsorbing and separating a boron compound dissolved in wastewater or the like by using a boron adsorbing resin and collecting the boron compound.

【０００２】[0002]

【従来の技術】各種製造工場のプラント排水、清掃工場
排水等には、ホウ酸塩、ホウ酸、もしくはホウ酸イオン
の形態で溶存している溶存ホウ素化合物は、環境汚染物
質としてその排出が厳しく規制されている。このため、
溶存ホウ素化合物の分離、除去手段も多く提案され、た
とえば、逆浸透膜を利用する方法、ホウ素吸着樹脂を利
用する方法、希土類元素の含水酸化物を利用する方法、
アルミニウム化合物、カルシウム化合物等によりホウ素
化合物を凝集、分離する方法があげられる。通常はこれ
らの方法の中から適宜に選択して、排水からホウ素を分
離し除去している。このうち、ホウ素吸着樹脂を利用す
る方法は、凝集、分離法に較べ大量の汚泥物質を発生す
ることがなく、逆浸透膜法に較べても低濃度にまでホウ
素化合物を除去することができる利点があって、広く利
用されている。2. Description of the Related Art Dissolved boron compounds, which are dissolved in the form of borate, boric acid, or borate ions, are severely polluted as environmental pollutants in plant wastewater of various manufacturing plants and wastewater of cleaning plants. It is regulated. For this reason,
Many means for separating and removing dissolved boron compounds have also been proposed, for example, a method using a reverse osmosis membrane, a method using a boron adsorbing resin, a method using a hydroxide of a rare earth element,
Examples thereof include a method of aggregating and separating a boron compound with an aluminum compound, a calcium compound or the like. Usually, boron is separated and removed from wastewater by appropriately selecting from these methods. Among them, the method using the boron adsorbing resin does not generate a large amount of sludge substance as compared with the coagulation and separation methods, and has an advantage that the boron compound can be removed to a lower concentration than the reverse osmosis membrane method. Therefore, it is widely used.

【０００３】しかし、ホウ素吸着樹脂の利用は樹脂の再
生を伴うものであり、再生の際に発生する大量の再生廃
液中には分離されたホウ素化合物が高濃度に含まれ、そ
の処分に要するコストを無視できないという問題があ
る。However, the use of the boron-adsorbed resin involves the regeneration of the resin, and a large amount of the recycled waste liquid generated during the regeneration contains the separated boron compound in a high concentration, and the cost required for its disposal. There is a problem that cannot be ignored.

【０００４】その対策として、たとえば、特開平１１−
２３５５９４号公報には、前記再生廃液をホウ素吸着分
離工程の前処理工程として付設した不溶性沈殿物生成工
程に還流して処理する方法が、特開平１１−１６９８６
４号公報には、前処理工程である蒸発濃縮成工程に還
流、処理する方法が記載されている。このほか、再生廃
液中のホウ素化合物を凝集・分離する方法、再生条件を
徹底的に再検討して再生廃液の発生量を極力少なくする
方法等も考えられているが、いずれも一長一短がある。As a countermeasure, for example, Japanese Patent Laid-Open No. 11-
Japanese Patent Laid-Open No. 11-16986 discloses a method in which the recycled waste liquid is treated by refluxing it to an insoluble precipitate forming step attached as a pretreatment step of a boron adsorption separation step.
Japanese Patent Publication No. 4 discloses a method of refluxing and treating in an evaporative concentration step which is a pretreatment step. In addition, a method of aggregating and separating the boron compound in the waste liquid for recycling, a method of thoroughly reconsidering the recycling conditions to reduce the amount of waste liquid generated as much as possible have been considered, but both have advantages and disadvantages.

【０００５】[0005]

【発明が解決しようとする課題】さて、前記の排水中の
ホウ素分離、除去手段は、いずれもホウ素を環境有害物
質として分離、除去することを目的とする。本発明で
は、この問題を前記の方法とは別の観点、すなわち、ホ
ウ素の分離、除去とともにホウ素の有効利用を目的とし
て検討した結果、完成されたものである。The above-mentioned means for separating and removing boron in wastewater are intended to separate and remove boron as an environmentally harmful substance. The present invention has been completed as a result of studying this problem from a viewpoint different from the above method, that is, for the purpose of effective use of boron as well as separation and removal of boron.

【０００６】[0006]

【課題を解決するための手段】本発明は、前記課題を解
決するために、ホウ素吸着樹脂を充填したホウ素吸着塔
を用いて排水中のホウ素を吸着分離し、酸性及びアルカ
リ性の樹脂再生水溶液を用いてホウ素吸着樹脂を再生す
るとともに、吸着樹脂からホウ素を脱着して樹脂再生水
溶液側に移行させ再生排水とし、脱着したホウ素を含む
再生排水を活性炭吸着層を通過させることにより着色物
質等の不純物を除去し、再生排水中に残ったホウ素化合
物を精製して、回収することを特徴とする排水中のホウ
素を回収する方法を提供する。前記の再生排水は、中和
した後、活性炭吸着層を通過させることが望ましい。[Means for Solving the Problems] In order to solve the above problems, the present invention uses a boron adsorption tower filled with a boron adsorption resin to adsorb and separate boron in wastewater to obtain an acidic and alkaline resin regeneration aqueous solution. Impurities such as coloring substances by regenerating the boron adsorption resin by using it, desorbing the boron from the adsorption resin and transferring it to the resin regeneration aqueous solution side for regeneration wastewater, and passing the regeneration wastewater containing the desorbed boron through the activated carbon adsorption layer. The present invention provides a method for recovering boron in wastewater, characterized in that the boron compound remaining in the recycled wastewater is purified and recovered. It is desirable that the regenerated waste water be passed through the activated carbon adsorption layer after being neutralized.

【０００７】また本発明は、ホウ素吸着樹脂を充填した
ホウ素吸着塔と、吸着樹脂の再生排水の排出系統に設け
た活性炭吸着処理装置と活性炭吸着処理装置の下流に設
けたホウ素化合物の精製、回収装置とからなることを特
徴とする排水中のホウ素を回収する装置を提供する。前
記装置において、活性炭吸着処理装置の上流側に再生排
水の中和装置を設けておくことが好ましい。The present invention is also directed to a boron adsorption tower filled with a boron adsorption resin, an activated carbon adsorption treatment device provided in a drainage system for regenerating the adsorption resin, and a purification and recovery of a boron compound provided downstream of the activated carbon adsorption treatment device. An apparatus for recovering boron in wastewater is provided. In the above device, it is preferable to provide a neutralization device for the recycled waste water on the upstream side of the activated carbon adsorption treatment device.

【０００８】[0008]

【発明の実施の形態】本発明について説明する。もとも
とホウ素化合物は種々の産業分野や日常生活において広
く利用されている有用な物質である。従って再生排水中
のホウ素を回収して有効利用することができれば一挙両
得となり、甚だ好都合である。前記したホウ素の分離方
法のうち、ホウ素化合物を汚泥として凝集、分離する方
法はホウ素化合物を取得するためには汚泥から抽出等で
再度分離する必要があり、多くの工程が必要になるの
で、好ましくない。その点、ホウ素を吸着分離する方法
は必ずしも凝集、汚泥化して分離する必要はないが、再
生廃水が茶褐色に着色しており、例えばホウ酸として回
収し有効利用するにも、この着色成分が支障になってホ
ウ素の有効利用が阻害される。BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described. Originally, boron compounds are useful substances that are widely used in various industrial fields and everyday life. Therefore, if boron in the recycled wastewater can be recovered and used effectively, it would be a great advantage, and it would be very convenient. Of the above-mentioned boron separation methods, a method of aggregating and separating a boron compound as sludge requires separation again from the sludge by extraction or the like in order to obtain the boron compound, and many steps are required, which is preferable. Absent. In that respect, the method of adsorbing and separating boron does not necessarily require coagulation and sludge separation, but the recycled wastewater is colored brown, and even if it is recovered and effectively used as boric acid, for example, this coloring component interferes. Therefore, the effective use of boron is hindered.

【０００９】さて、ホウ素を含む排水は、通常、ｐＨを
調整された後、Ｎ−メチルグルカミンを官能基とするス
チレン系キレート樹脂等のホウ素吸着樹脂を充填したホ
ウ素吸着・分離装置に供給され、含有するホウ素は吸着
によって分離される。吸着樹脂へのホウ素の吸着量が飽
和又は飽和近くになると、排水の供給を停止してホウ素
吸着樹脂の再生工程に切り替えられる。再生工程におい
ては、逆洗水によりホウ素吸着樹脂を逆洗し、ついで、
逆洗水を塩酸又は硫酸などの再生溶液に切り替え、ホウ
素吸着樹脂に通液して吸着したホウ素を脱着させ、再生
排水として導出する。脱着が終了した時点で再生溶液の
供給を停止し、吸着・分離装置内に押出水を供給して装
置内を置換し、水洗する。さらに、アルカリ水溶液又は
酸性水溶液に切り替えてホウ素吸着樹脂を中和し、再生
する。そして再度、吸着装置内に押出水を供給し、装置
内を置換、水洗して再生工程を終了し、再び排水処理操
作に戻る。The wastewater containing boron is usually adjusted in pH and then supplied to a boron adsorption / separation device filled with a boron adsorption resin such as a styrene chelate resin having N-methylglucamine as a functional group. , Contained boron is separated by adsorption. When the amount of boron adsorbed on the adsorption resin becomes saturated or near saturation, the supply of waste water is stopped and the process is switched to the step of regenerating the boron adsorption resin. In the regeneration process, the boron adsorption resin is backwashed with backwash water, and then
The backwash water is switched to a regeneration solution such as hydrochloric acid or sulfuric acid, and the solution is passed through a boron adsorbing resin to desorb the adsorbed boron, which is then discharged as regeneration wastewater. When the desorption is completed, the supply of the regeneration solution is stopped, the extruded water is supplied into the adsorption / separation device to replace the inside of the device, and the water is washed. Further, the boron adsorbing resin is neutralized and regenerated by switching to an alkaline aqueous solution or an acidic aqueous solution. Then, the extruded water is supplied again into the adsorption device, the inside of the device is replaced, and the device is washed with water to end the regeneration process, and the drainage treatment operation is again performed.

【００１０】本発明において上記の導出した再生排水
は、活性炭吸着槽を通過させることにより着色成分等の
不純物を吸着除去する。活性炭吸着処理に先立って、再
生廃水にアルカリを添加して中和しておくと、吸着操作
を円滑に進行させることができて好ましい。活性炭吸着
処理条件、例えば総吸着容量等は、再生廃水の操作条
件、着色物質濃度等により適宜に決めればよい。活性炭
吸着法を用いることで、排水中に含まれる多様な不純物
を同時に除去することができ、操作の簡単さやコスト面
で有利となる。不純物を取り除いた再生排水中のホウ素
化合物は、公知の手段により容易に精製、回収すること
ができる。In the present invention, the above-mentioned reclaimed drainage water is passed through an activated carbon adsorption tank to adsorb and remove impurities such as coloring components. It is preferable to add an alkali to the regenerated wastewater to neutralize it before the activated carbon adsorption treatment, because the adsorption operation can proceed smoothly. The activated carbon adsorption treatment conditions, such as the total adsorption capacity, may be appropriately determined depending on the operating conditions of the recycled wastewater, the concentration of the coloring substance, and the like. By using the activated carbon adsorption method, various impurities contained in the waste water can be removed at the same time, which is advantageous in terms of easiness of operation and cost. The boron compound in the recycled wastewater from which impurities have been removed can be easily purified and recovered by known means.

【００１１】[0011]

【発明の効果】本発明を利用すれば、排水中に含まれる
ホウ素を、従来のように汚泥等の形態で含有させて廃棄
物処理するものではなく、利用可能な資源として分離、
回収することができるので、環境保護、資源有効利用の
両面からの効果を期待できる。EFFECTS OF THE INVENTION According to the present invention, boron contained in wastewater is not contained in the form of sludge or the like as in the conventional case and treated as waste, but separated as an available resource,
Since they can be collected, the effects from both aspects of environmental protection and effective use of resources can be expected.

───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 4D024 AA04 AB14 BA02 BA18 BC01 CA01 DA08 DB20 4G066 AC14B AC33B CA21 DA08 GA11    ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4D024 AA04 AB14 BA02 BA18 BC01                       CA01 DA08 DB20                 4G066 AC14B AC33B CA21 DA08                       GA11

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】ホウ素吸着樹脂を充填したホウ素吸着塔を
用いて排水中のホウ素を吸着分離し、酸性およびアルカ
リ性の樹脂再生水溶液を用いてホウ素吸着樹脂を再生す
るとともに、吸着樹脂からホウ素を脱着して樹脂再生水
溶液側に移行させて再生排水とし、脱着したホウ素を含
む再生排水を活性炭吸着層を通過させて着色物質等を分
離し、再生排水中に残ったホウ素化合物を精製して、回
収することを特徴とする排水中のホウ素を回収する方
法。1. A boron adsorption tower filled with a boron adsorption resin is used to adsorb and separate boron in wastewater, an acidic and alkaline resin regeneration aqueous solution is used to regenerate the boron adsorption resin, and the boron is desorbed from the adsorption resin. Then, it is transferred to the resin regeneration aqueous solution side to be recycled wastewater, and the recycled wastewater containing desorbed boron is passed through the activated carbon adsorption layer to separate coloring substances, etc., and the boron compound remaining in the recycled wastewater is purified and recovered. A method for recovering boron in wastewater, comprising: 【請求項２】前記再生排水を、中和した後、活性炭吸着
層を通過させることを特徴とする請求項１記載の排水中
のホウ素を回収する方法。2. The method for recovering boron in wastewater according to claim 1, wherein the recycled wastewater is neutralized and then passed through an activated carbon adsorption layer. 【請求項３】ホウ素吸着樹脂を充填したホウ素吸着塔
と、吸着樹脂の再生排水の排出系統に設けた活性炭吸着
処理装置と、活性炭吸着処理装置の下流に設けたホウ素
化合物の精製、回収装置とからなることを特徴とする排
水中のホウ素を回収する装置。3. A boron adsorption tower filled with a boron adsorption resin, an activated carbon adsorption treatment device provided in a drainage system for regenerating the adsorption resin, and a boron compound purification and recovery device provided downstream of the activated carbon adsorption treatment device. A device for recovering boron in wastewater, which comprises: 【請求項４】活性炭吸着処理装置の上流側に再生排水の
中和装置を設けたことを特徴とする請求項３記載の排水
中のホウ素を回収する装置。4. An apparatus for recovering boron in wastewater according to claim 3, further comprising a neutralization apparatus for reclaimed wastewater provided upstream of the activated carbon adsorption treatment apparatus.