JP2005193167A - Drainage purification method and purification method - Google Patents

Drainage purification method and purification method Download PDF

Info

Publication number
JP2005193167A
JP2005193167A JP2004002597A JP2004002597A JP2005193167A JP 2005193167 A JP2005193167 A JP 2005193167A JP 2004002597 A JP2004002597 A JP 2004002597A JP 2004002597 A JP2004002597 A JP 2004002597A JP 2005193167 A JP2005193167 A JP 2005193167A
Authority
JP
Japan
Prior art keywords
fluorine
hydrotalcite
adsorption
calcium fluoride
calcium
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Withdrawn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
JP2004002597A
Other languages
Japanese (ja)
Inventor
Hodaka Ikeda
穂高 池田
Kenichi Ito
健一 伊藤
Naseishi Akita
奈生子 秋田
Koji Kanekawa
浩司 金川
Tsutomu Sato
努 佐藤
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.)
Sophia Co Ltd
Original Assignee
Sophia 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 Sophia Co Ltd filed Critical Sophia Co Ltd
Priority to JP2004002597A priority Critical patent/JP2005193167A/en
Priority to PCT/JP2004/007315 priority patent/WO2005066080A1/en
Publication of JP2005193167A publication Critical patent/JP2005193167A/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/28—Treatment of water, waste water, or sewage by sorption
    • C02F1/281—Treatment of water, waste water, or sewage by sorption using inorganic sorbents
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F11/00—Treatment of sludge; Devices therefor
    • C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/12—Halogens or halogen-containing compounds
    • C02F2101/14—Fluorine or fluorine-containing compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2301/00—General aspects of water treatment
    • C02F2301/08—Multistage treatments, e.g. repetition of the same process step under different conditions
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2303/00—Specific treatment goals
    • C02F2303/16—Regeneration of sorbents, filters

Landscapes

  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Organic Chemistry (AREA)
  • Water Treatment By Sorption (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Removal Of Specific Substances (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drainage purification method by which treated water of very low fluorine concentration can be obtained by removing fluorine contained in fluorin-containing drainage to the utmost without necessitating a large quantity of a calcium compound such as calcium chloride and calcium hydroxide or a flocculant and discharging a large quantity of sludge. <P>SOLUTION: This drainage purification method comprises the steps of: adding the calcium compound to the fluorine-containing drainage to produce calcium fluoride; subjecting a calcium fluoride-containing reaction product to solid-liquid separation such as a flocculating/settling method to remove the calcium fluoride; adjusting the pH of the calcium fluoride-removed treated water; adding hydrotalcite to the pH-adjusted treated water to adsorb remaining fluorine on hydrotalcite (called a fluorine adsorption step); subjecting the treated water containing fluorine-adsorbed hydrotalcite to solid-liquid separation such as the flocculating/settling method to remove the fluorine-adsorbed hydrotalcite; desorbing fluorine from the fluorine-adsorbed hydrotalcite (called a fluorine desorption step); adding the fluorine-desorbed hydrotalcite again at the fluorine adsorption step and; mixing the fluorine-containing drainage before calcium fluoride is produced with the fluorine-containing water produced at the fluorine desorption step. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明は、例えば半導体工場や発電所等から排水されるフッ素含有排水からフッ素を除去する排水浄化方法及び浄化方法に関する。   The present invention relates to a wastewater purification method and a purification method for removing fluorine from fluorine-containing wastewater drained from, for example, a semiconductor factory or power plant.

例えば半導体工場や発電所等から排水されるフッ素含有排水からフッ素を除去する技術として、水酸化カルシウムや塩化カルシウムとフッ素を反応させてフッ化カルシウムを生成し、凝集・沈殿する方式が行われている。その除去工程は、例えばフッ素を含有する酸性排水にｐＨ調整剤を添加してｐＨ調整し、ｐＨ調整した排水を反応槽に送出し、反応槽で水酸化カルシウムや塩化カルシウムを添加してフッ化カルシウムを生成する。その後、フッ化カルシウムを有する反応液を凝集槽に送出し、凝集剤を添加してフッ化カルシウムを凝集し、更に、沈殿槽で凝集したフッ化カルシウムを含有する汚泥を沈殿して除去するものである。   For example, as a technology for removing fluorine from fluorine-containing wastewater discharged from semiconductor factories, power plants, etc., there is a method in which calcium fluoride is reacted with fluorine to produce calcium fluoride, and agglomerates and precipitates. Yes. For example, the pH is adjusted by adding a pH adjusting agent to acidic wastewater containing fluorine, and the pH-adjusted wastewater is sent to the reaction tank, and calcium hydroxide or calcium chloride is added in the reaction tank to fluorinate. Produces calcium. After that, the reaction liquid having calcium fluoride is sent to the coagulation tank, the coagulant is added to coagulate the calcium fluoride, and the sludge containing calcium fluoride coagulated in the precipitation tank is precipitated and removed. It is.

また、フッ素含有排水からフッ素を除去する技術に関連する公知文献としては特許文献１がある。特許文献１には、塩化カルシウムを用いて排水中のフッ素を除去する処理方法が記載され、塩化カルシウムの溶液を排水に添加する前に、塩化カルシウムの溶液の全量或いは一部のｐＨを予め１１．５以上に調整し、その溶液を排水と反応させるもので、塩化カルシウムの使用量を低減し、或いは凝集剤の多量使用を回避できることが開示されている。   Moreover, there is Patent Document 1 as a known document related to a technique for removing fluorine from fluorine-containing wastewater. Patent Document 1 describes a treatment method for removing fluorine in waste water using calcium chloride. Before adding the calcium chloride solution to the waste water, the total amount or a partial pH of the calcium chloride solution is set to 11 in advance. It is disclosed that the amount is adjusted to 5 or more and the solution is reacted with waste water, so that the amount of calcium chloride used can be reduced or a large amount of flocculant can be avoided.

特開平７−２１４０７２号公報JP-A-7-214072

ところで、上記塩化カルシウム等とフッ素の反応でフッ化カルシウムを生成し、フッ化カルシウムを含有する汚泥を除去する場合、高いレベルの基準値以下の処理水とするようにフッ素を除去するには、多量に塩化カルシウムや水酸化カルシウム等のカルシウム化合物を必要とし、加えて、凝集沈殿で回収する場合には多量な凝集剤等を必要とし、又、排出される汚泥量が極めて多量になるため、フッ素が高レベルの基準値以下の処理水となるようにフッ素を除去することは現実的に困難である。そのため、かような問題点を有せず、排水からフッ素を高レベルに除去することができる技術が切望されていた。   By the way, when calcium fluoride is generated by reaction of the above calcium chloride and the like and fluorine and sludge containing calcium fluoride is removed, in order to remove fluorine so as to be treated water of a high level or less, Calcium compounds such as calcium chloride and calcium hydroxide are required in large quantities. In addition, a large amount of flocculant is required to collect by coagulation sedimentation, and the amount of sludge discharged is extremely large. It is practically difficult to remove fluorine so that it becomes treated water below a high level reference value. Therefore, there has been a strong demand for a technique that can remove fluorine from wastewater to a high level without having such problems.

本発明は上記課題に鑑み提案するものであって、多量の塩化カルシウム若しくは水酸化カルシウム等のカルシウム化合物や、凝集剤を必要とせず、且つ多量な汚泥量を排出することが無く、フッ素含有排水のフッ素を高レベルに除去し、非常に低フッ素濃度の処理水とすることができる排水浄化方法を提供することを目的とする。また、他の目的は、ハイドロタルサイト類を再生して効率的に利用し、低コストで高度なフッ素の浄化を行うことができる排水浄化方法及び浄化方法を提供することにある。   The present invention is proposed in view of the above-mentioned problems, and does not require a large amount of calcium compound such as calcium chloride or calcium hydroxide or a flocculant, and does not discharge a large amount of sludge. An object of the present invention is to provide a method for purifying wastewater that can remove the fluorine at a high level and make treated water with a very low fluorine concentration. Another object of the present invention is to provide a wastewater purification method and a purification method that can regenerate and efficiently use hydrotalcites and can perform advanced fluorine purification at low cost.

本発明の排水浄化方法は、フッ素含有排水に、必要に応じてｐＨを調整し、カルシウム化合物を添加してフッ化カルシウムを生成する工程と、該フッ化カルシウム生成後の反応液を固液分離してフッ化カルシウムを除去する工程と、該フッ化カルシウム除去後の処理水のｐＨを調整し、ハイドロタルサイト類を添加してハイドロタルサイト類に残留するフッ素を吸着させる工程と、該吸着後の処理水を固液分離してフッ素吸着後のハイドロタルサイト類を除去する工程とを、少なくとも有することを特徴とする。   The wastewater purification method of the present invention includes a step of adjusting pH to fluorine-containing wastewater as needed, adding a calcium compound to produce calcium fluoride, and solid-liquid separation of the reaction solution after the calcium fluoride is produced Removing calcium fluoride, adjusting the pH of the treated water after removing calcium fluoride, adding hydrotalcite to adsorb fluorine remaining in hydrotalcite, and the adsorption And a process of removing hydrotalcite after adsorption of fluorine by solid-liquid separation of the subsequent treated water.

尚、本発明に於ける、フッ化カルシウムやフッ素吸着後のハイドロタルサイト類を固液分離して除去する場合の固液分離は、例えば凝集剤を添加して固相を凝集沈殿する、或いは空気のバブリングによる浮上分離で固相を回収する、或いはフィルター等を用いる膜濾過で固相を回収するなど適宜であり、又、カルシウム化合物は、塩化カルシウム若しくは水酸化カルシウムとすると好適であるが、フッ素と反応してフッ化カルシウムを生成できるものであれば適宜であり、例えば炭酸カルシウム等としてもよい。また、ハイドロタルサイト類にフッ素を吸着させる場合の処理水等のｐＨは、ｐＨ４〜１０とし、より好適にはｐＨ５〜７とするとよい。   In the present invention, solid-liquid separation in the case where calcium fluoride and hydrotalcite after adsorption of fluorine are removed by solid-liquid separation, for example, a flocculant is added to coagulate and precipitate the solid phase, or It is appropriate to recover the solid phase by flotation separation by air bubbling, or recover the solid phase by membrane filtration using a filter or the like, and the calcium compound is preferably calcium chloride or calcium hydroxide, Any material can be used as long as it can react with fluorine to produce calcium fluoride, and may be calcium carbonate, for example. In addition, the pH of the treated water or the like when fluorine is adsorbed to hydrotalcites is preferably 4 to 10, more preferably 5 to 7.

更に、本発明の排水浄化方法は、前記除去したフッ素吸着後のハイドロタルサイト類に対してフッ素脱離処理を施す工程と、該フッ素脱離処理後のハイドロタルサイト類をフッ素吸着工程で再度添加する工程を有すると共に、該フッ化カルシウム生成前のフッ素含有排水に該フッ素脱離処理で生成されるフッ素含有水を合わせる工程を有することを特徴とする。   Furthermore, the waste water purification method of the present invention comprises a step of subjecting the removed hydrotalcite after fluorine adsorption to a fluorine desorption treatment, and the hydrotalcite after fluorine desorption treatment is again performed in the fluorine adsorption step. And a step of adding fluorine-containing water produced by the fluorine desorption treatment to the fluorine-containing wastewater before the calcium fluoride is produced.

更に、本発明の排水浄化方法は、前記フッ素脱離処理工程が、前記フッ素吸着後のハイドロタルサイト類をｐＨが９＜ｐＨ＜１１の溶液中で攪拌してフッ素脱離処理を施すものであることを特徴とし、好適には前記フッ素脱離処理を施す溶液のｐＨは略１０とするとよい。   Furthermore, in the wastewater purification method of the present invention, the fluorine desorption treatment step performs the fluorine desorption treatment by stirring the hydrotalcite after fluorine adsorption in a solution having a pH of 9 <pH <11. Preferably, the pH of the solution to be subjected to the fluorine desorption treatment is preferably about 10.

また、本発明の排水浄化方法は、フッ素含有排水に、必要に応じてｐＨを調整し、カルシウム化合物を添加してフッ化カルシウムを生成する工程と、該フッ化カルシウム生成後の反応液にハイドロタルサイト類を添加してハイドロタルサイト類に残留するフッ素を吸着させる工程と、該吸着後の反応液を固液分離してフッ化カルシウム及びフッ素吸着後のハイドロタルサイト類を除去する工程とを、少なくとも有することを特徴とする。   In addition, the wastewater purification method of the present invention includes a step of adjusting the pH of fluorine-containing wastewater as necessary, adding a calcium compound to produce calcium fluoride, and hydrolyzing the reaction liquid after the calcium fluoride is produced. A step of adding talcite to adsorb fluorine remaining in hydrotalcite; a step of solid-liquid separation of the reaction liquid after the adsorption to remove calcium fluoride and hydrotalcite after fluorine adsorption; It is characterized by having at least.

更に、本発明の排水浄化方法は、前記ハイドロタルサイト類がハイドロタルサイトであることを特徴とする。ハイドロタルサイト類（層状複水酸化鉱物、ＬＤＨ）は良好な陰イオン吸着特性を示すことから、本発明のフッ素或いはフッ素イオンを吸着するハイドロタルサイト類には、一般式：［Ｍ２＋ １−ｘＭ３＋ ｘ（ＯＨ）２］［Ａｎ− ｘ／ｎ・ｚＨ２Ｏ］（Ｍ２＋は２価金属、Ｍ３＋は３価金属、Ａｎ−はｎ価の陰イオン）で表されるハイドロタルサイト類の適宜のものを用いることが可能であるが、例えばハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６ＣＯ３・４Ｈ２Ｏとすると好適である。 Furthermore, the waste water purification method of the present invention is characterized in that the hydrotalcite is hydrotalcite. Since hydrotalcites (layered double hydroxide mineral, LDH) exhibit good anion adsorption characteristics, the hydrotalcites that adsorb fluorine or fluorine ions of the present invention have the general formula: [M 2+ 1− represented by x M 3+ x (OH) 2 ] [a n- x / n · zH 2 O] (M 2+ is a divalent metal, M 3+ is a trivalent metal, a n-n-valent anion) An appropriate hydrotalcite can be used, but for example, hydrotalcite: Mg 6 Al 2 (OH) 16 CO 3 .4H 2 O is preferable.

また、本発明の浄化方法は、フッ素を含有する浄化対象にハイドロタルサイト類を添加してフッ素を吸着させる浄化方法に於いて、フッ素吸着後のハイドロタルサイト類を９＜ｐＨ＜１１の溶液中で攪拌してフッ素脱離処理を施し、該フッ素脱離処理後のハイドロタルサイト類を浄化対象に再度添加してフッ素を吸着させることを特徴とし、好適には前記フッ素脱離処理を施す溶液のｐＨは略１０とするとよい。尚、フッ素を含有する浄化対象は、排水以外に土壌等とすることも可能である。   The purification method of the present invention is a purification method in which hydrotalcite is adsorbed by adding hydrotalcite to a purification target containing fluorine, and the hydrotalcite after fluorine adsorption is a solution of 9 <pH <11. The fluorine desorption treatment is performed by stirring in the solution, and the hydrotalcite after the fluorine desorption treatment is added again to the purification target to adsorb fluorine, and preferably the fluorine desorption treatment is performed. The pH of the solution is preferably about 10. In addition, the purification | cleaning object containing a fluorine can also be soil etc. besides drainage.

本発明の排水浄化方法は、多量の塩化カルシウム若しくは水酸化カルシウム等のカルシウム化合物や、多量の凝集剤を用いること無く、且つ多量な汚泥を排出することが無く、フッ素含有排水のフッ素を非常に高レベルに除去することができる。例えばフッ素含有排水を公共用水域排出基準であり８ｐｐｍ以下にする等、フッ素含有排水を非常に低フッ素濃度の処理水にすることが可能である。更に、多量の塩化カルシウム等や凝集剤を用い無くても良く、又、多量の汚泥を排出することも無いことから、薬剤費や汚泥処理費等を削減し、高レベルのフッ素除去が低コストで効率的に可能である。   The method for purifying wastewater of the present invention does not use a large amount of calcium compound such as calcium chloride or calcium hydroxide, a large amount of flocculant, and does not discharge a large amount of sludge. Can be removed to a high level. For example, fluorine-containing wastewater can be made into treated water with a very low fluorine concentration, such as 8 ppm or less, which is a public water discharge standard. Furthermore, it is not necessary to use a large amount of calcium chloride or a flocculant, and since a large amount of sludge is not discharged, the cost of chemical treatment and sludge treatment is reduced, and high-level fluorine removal is low cost. Is possible efficiently.

また、本発明の排水浄化方法或いは浄化方法は、フッ素吸着後のハイドロタルサイト類からフッ素を脱離し、脱離処理後のハイドロタルサイト類で再度フッ素を吸着させることにより、ハイドロタルサイト類を再生して有効利用することが可能であり、非常に低コストで高度なフッ素の浄化を行うことができる。特に、フッ素吸着後のハイドロタルサイト類を９＜溶液ｐＨ＜１１の溶液中、より好適にはｐＨが略１０の溶液中で攪拌して脱離処理を行うことにより、非常に高い再生効率を実現することができる。   Moreover, the wastewater purification method or purification method of the present invention comprises desorbing fluorine from hydrotalcite after fluorine adsorption, and adsorbing fluorine again with hydrotalcite after desorption treatment, It is possible to recycle and effectively use it, and it is possible to perform advanced fluorine purification at a very low cost. In particular, the hydrotalcite after adsorption of fluorine is stirred in a solution of 9 <solution pH <11, more preferably in a solution having a pH of about 10, so as to perform a desorption treatment, thereby achieving a very high regeneration efficiency. Can be realized.

以下では、本発明について、第１、第２実施形態の排水浄化処理及び実施例に基づき具体的に説明するが、本発明は係る実施形態や実施例に限定されるものではない。   Below, although this invention is demonstrated concretely based on the waste water purification process and Example of 1st, 2nd embodiment, this invention is not limited to the embodiment and Example which concern.

先ず、ハイドロタルサイトを循環して再利用し、フッ素含有排水からフッ素を除去して浄化する第１実施形態の排水浄化処理について説明する。第１実施形態の排水浄化処理は、図１に示すように、フッ素を含有する排水を１次反応凝集沈殿槽１に導入し、１次反応凝集沈殿槽１にｐＨ調整剤を添加して、フッ素含有排水を所定のｐＨ、例えばｐＨ８〜１０程度に調整する。前記添加するｐＨ調整剤には酸やアルカリの適宜のものを用いることが可能であり、例えばフッ素含有排水が酸性排水である場合には、水酸化ナトリウム（ＮａＯＨ）等のアルカリをｐＨ調整剤として添加する。   First, the drainage purification process of the first embodiment in which hydrotalcite is circulated and reused to remove and purify fluorine from fluorine-containing wastewater will be described. As shown in FIG. 1, the waste water purification treatment of the first embodiment introduces fluorine-containing waste water into the primary reaction coagulation sedimentation tank 1, adds a pH adjuster to the primary reaction coagulation sedimentation tank 1, The fluorine-containing waste water is adjusted to a predetermined pH, for example, about pH 8-10. As the pH adjuster to be added, an appropriate acid or alkali can be used. For example, when the fluorine-containing wastewater is acidic wastewater, an alkali such as sodium hydroxide (NaOH) is used as the pH adjuster. Added.

そして、１次反応凝集沈殿槽１内のｐＨを調整したフッ素含有排水に塩化カルシウム（ＣａＣｌ２）を添加して、フッ素含有排水中のフッ素イオン（Ｆ−）と塩化カルシウムを反応させ、Ｃａ２＋＋２Ｆ−→ＣａＦ２ の反応によってフッ化カルシウム（ＣａＦ２）を生成する。更に、１次反応凝集沈殿槽１に硫酸バンドやＰＡＣ等の凝集剤を添加してフッ化カルシウムを凝集し、フッ化カルシウムを含む汚泥を沈殿させる。沈殿した汚泥は１次反応凝集沈殿槽１から脱水機４に導出され、脱水機４で汚泥を脱水し、脱水ケーキとして排出する。 Then, by adding calcium chloride (CaCl 2) in the fluorine-containing waste water to adjust the pH of the primary reaction coagulating sedimentation tank 1, the fluorine ion in the fluorine-containing waste water (F -) is reacted with calcium chloride, Ca 2+ Calcium fluoride (CaF 2 ) is generated by the reaction of + 2F − → CaF 2 . Further, a flocculant such as sulfuric acid band or PAC is added to the primary reaction coagulation sedimentation tank 1 to coagulate calcium fluoride and precipitate sludge containing calcium fluoride. The precipitated sludge is led out from the primary reaction coagulation sedimentation tank 1 to the dehydrator 4, where the sludge is dehydrated and discharged as a dehydrated cake.

また、１次反応凝集沈殿槽１で汚泥を除去して得られる１次処理水は、２次反応凝集沈殿槽２に導入され、２次反応凝集沈殿槽２にｐＨ調整剤を添加して、１次処理水を所定のｐＨ、例えば後述するハイドロタルサイトの吸着性能が最も効果を発揮するｐＨ６前後に調整する。前記添加するｐＨ調整剤には適宜のものを用いることが可能であり、例えば１次処理水に、塩酸（ＨＣｌ）等の酸をｐＨ調整剤として添加する。   Moreover, the primary treated water obtained by removing sludge in the primary reaction coagulation sedimentation tank 1 is introduced into the secondary reaction coagulation sedimentation tank 2, and a pH adjuster is added to the secondary reaction coagulation sedimentation tank 2, The primary treated water is adjusted to a predetermined pH, for example, around pH 6 at which the hydrotalcite adsorption performance described below is most effective. As the pH adjuster to be added, an appropriate one can be used. For example, an acid such as hydrochloric acid (HCl) is added as a pH adjuster to the primary treated water.

そして、２次反応凝集沈殿槽２内のｐＨを調整した１次処理水に、ハイドロタルサイトを添加し、１次処理水中に残留するフッ素イオン（Ｆ−）をハイドロタルサイトに吸着させる。前記添加するハイドロタルサイトは組成式：Ｍｇ６Ａｌ２（ＯＨ）１６ＣＯ３・４Ｈ２Ｏの層状複水酸化鉱物であり、アニオン交換性を有し、様々なアニオンを層間に挿入することが可能である。ハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６ＣＯ３・４Ｈ２Ｏの大部分は、前記フッ素イオン（Ｆ−）を層間に取り込こんで吸着し、フッ素イオンを吸着したハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６（Ｆ−１）２・４Ｈ２Ｏが生成される。 Then, hydrotalcite is added to the primary treated water whose pH in the secondary reaction coagulation sedimentation tank 2 is adjusted, and fluorine ions (F − ) remaining in the primary treated water are adsorbed on the hydrotalcite. The hydrotalcite to be added is a layered double hydroxide mineral having a composition formula: Mg 6 Al 2 (OH) 16 CO 3 .4H 2 O, has anion exchange properties, and various anions can be inserted between the layers. Is possible. Hydrotalcite: Most of Mg 6 Al 2 (OH) 16 CO 3 .4H 2 O takes in and adsorbs the fluorine ions (F − ) between the layers, and hydrotalcite adsorbs the fluorine ions: Mg 6 Al 2 (OH) 16 (F −1 ) 2 .4H 2 O is produced.

更に、２次反応凝集沈殿槽２に硫酸バンドやＰＡＣ等の凝集剤を添加して、フッ素イオンを吸着したハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６（Ｆ−１）２・４Ｈ２Ｏ、及びフッ素イオンを吸着できなかったハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６ＣＯ３・４Ｈ２Ｏを凝集して沈殿させる。前記凝集沈殿により、ハイドロタルサイトによるフッ素イオン吸着で一層フッ素濃度が低下した処理水が得られ、前記処理水は系外に排出され、又、フッ素を吸着したハイドロタルサイトを含むハイドロタルサイト或いは沈殿物はフッ素脱離槽３に送出される。 Further, a hydrotalcite: Mg 6 Al 2 (OH) 16 (F −1 ) 2 .4H 2 O in which a flocculant such as sulfuric acid band or PAC is added to the secondary reaction coagulation sedimentation tank 2 to adsorb fluorine ions. And hydrotalcite that could not adsorb fluorine ions: Mg 6 Al 2 (OH) 16 CO 3 .4H 2 O aggregates and precipitates. By the aggregation precipitation, treated water having a fluorine concentration further reduced by adsorption of fluorine ions by hydrotalcite is obtained, and the treated water is discharged out of the system, and hydrotalcite containing hydrotalcite that has adsorbed fluorine or The precipitate is sent to the fluorine desorption tank 3.

フッ素脱離槽３或いはフッ素脱離槽３へ至る送出経路に於いては、前記フッ素イオンを吸着したハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６（Ｆ−１）２・４Ｈ２Ｏを含むハイドロタルサイト或いは前記沈殿物を溶液に懸濁し、その溶液に水酸化ナトリウム（ＮａＯＨ）等のｐＨ調整剤を添加して、溶液のｐＨを所定のｐＨ、例えばｐＨ９〜１１、好適には１０前後に調整すると共に、フッ素を脱離しやすくするために二酸化炭素（ＣＯ２）を添加する。 The fluorine desorption tank 3 or the delivery path to the fluorine desorption tank 3 contains hydrotalcite adsorbed with the fluorine ions: Mg 6 Al 2 (OH) 16 (F −1 ) 2 .4H 2 O. The hydrotalcite or the precipitate is suspended in a solution, and a pH adjusting agent such as sodium hydroxide (NaOH) is added to the solution, and the pH of the solution is set to a predetermined pH, for example, pH 9 to 11, preferably around 10. And carbon dioxide (CO 2 ) is added to facilitate the elimination of fluorine.

そして、フッ素脱離槽３では、前記溶液を攪拌して、フッ素イオンを吸着したハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６（Ｆ−１）２・４Ｈ２Ｏからフッ素イオン（Ｆ−）を脱離してハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６ＣＯ３・４Ｈ２Ｏとし、フッ素を脱離した大部分のハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６ＣＯ３・４Ｈ２Ｏ、及びフッ素を脱離しきれなかったハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６（Ｆ−１）２・４Ｈ２Ｏで構成される固相と、フッ素イオン（Ｆ−１）を含む液相を固液分離する。 In the fluorine desorption tank 3, the solution is stirred and hydrotalcite adsorbed with fluorine ions: Mg 6 Al 2 (OH) 16 (F −1 ) 2 .4H 2 O to fluorine ions (F − ). And hydrotalcite: Mg 6 Al 2 (OH) 16 CO 3 .4H 2 O, and most of the hydrotalcite from which fluorine was eliminated: Mg 6 Al 2 (OH) 16 CO 3 .4H 2 O , And hydrotalcite that could not completely desorb fluorine: a liquid phase containing Mg 6 Al 2 (OH) 16 (F −1 ) 2 · 4H 2 O and a fluorine ion (F −1 ) Is separated into solid and liquid.

前記分離した固相は、フッ素脱離槽３から送出して２次反応凝集沈殿槽２に導入し、循環させて使用し、必要に応じて２次反応凝集沈殿槽２に新たなハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６ＣＯ３・４Ｈ２Ｏを導入する。また、前記分離したフッ素イオン（Ｆ−）を含む液相或いは溶液は、１次反応凝集沈殿槽１に返送し、１次反応凝集沈殿槽１で新たに導入されるフッ素含有排水と共に処理する。 The separated solid phase is sent out from the fluorine desorption tank 3 and introduced into the secondary reaction coagulation sedimentation tank 2 for circulation and used as needed in the secondary reaction coagulation sedimentation tank 2. : Mg 6 Al 2 (OH) 16 CO 3 .4H 2 O is introduced. The liquid phase or solution containing the separated fluorine ions (F − ) is returned to the primary reaction coagulation sedimentation tank 1 and treated with the fluorine-containing wastewater newly introduced in the primary reaction coagulation sedimentation tank 1.

上記第１実施形態の排水浄化処理は、１次反応凝集沈殿槽１及び２次反応凝集沈殿槽２とフッ素脱離槽３、脱水機４でフッ素含有排水からフッ素を除去し、フッ素脱離槽３で分離するハイドロタルサイトを再度利用するので、必要に応じてロス分のハイドロタルサイトを追加投入するのみで済み、ハイドロタルサイトの有効利用が可能である。更に、ハイドロタルサイトの消費量を低減し、低コスト化を図ることができる。更に、フッ化カルシウムの生成後に残留するフッ素イオンをハイドロタルサイトで吸着することにより、効率的にフッ素濃度が非常に低い処理水とすることができると共に、塩化カルシウム等や凝集剤を多量に用いる必要が無くなる。更に、フッ素を循環処理し、ハイドロタルサイトに吸着したフッ素も最終的にフッ化カルシウムとして回収することが可能である。   The waste water purification treatment of the first embodiment is performed by removing fluorine from fluorine-containing waste water with the primary reaction coagulation sedimentation tank 1 and the secondary reaction coagulation sedimentation tank 2, the fluorine desorption tank 3, and the dehydrator 4. Since the hydrotalcite separated in step 3 is reused, it is only necessary to add additional hydrotalcite for the loss if necessary, and the hydrotalcite can be used effectively. Furthermore, the consumption of hydrotalcite can be reduced and the cost can be reduced. Furthermore, by adsorbing the fluorine ions remaining after the formation of calcium fluoride with hydrotalcite, it is possible to efficiently make treated water with a very low fluorine concentration and to use a large amount of calcium chloride or a flocculant. There is no need. Furthermore, it is possible to finally recover the fluorine adsorbed on the hydrotalcite as calcium fluoride by circulating the fluorine.

尚、上記第１実施形態の排水浄化処理では、同一の１次反応凝集沈殿槽１で、ｐＨ調整処理、塩化カルシウムとの反応によるフッ化カルシウムの生成処理、凝集処理、沈殿処理を行う構成としたが、変形例として、例えばｐＨ調整槽、フッ化カルシウムを生成する反応槽、凝集槽、沈殿槽で各処理を行う構成、或いはこれらの適宜の処理の組み合わせを同一槽で行う構成等とすることが可能である。また、同様に、同一の２次反応凝集沈殿槽２で、ｐＨ調整処理、ハイドロタルサイトによるフッ素イオンの吸着処理、凝集処理、沈殿処理を行う構成としたが、例えばｐＨ調整槽、フッ素イオンの吸着処理を行う反応槽、凝集槽、沈殿槽で各処理を行う構成、或いはこれらの適宜の処理の組み合わせを同一槽で行う構成等とすることが可能である。   In the waste water purification process of the first embodiment, the same primary reaction coagulation sedimentation tank 1 is used to perform pH adjustment process, calcium fluoride production process by calcium chloride reaction, coagulation process, and precipitation process. However, as a modification, for example, a configuration in which each treatment is performed in a pH adjustment tank, a reaction tank for generating calcium fluoride, a coagulation tank, a precipitation tank, or a combination of these appropriate treatments in the same tank, etc. It is possible. Similarly, in the same secondary reaction coagulation sedimentation tank 2, pH adjustment treatment, fluorine ion adsorption treatment with hydrotalcite, coagulation treatment, and precipitation treatment are performed. A configuration in which each treatment is performed in a reaction tank, an agglomeration tank, and a precipitation tank in which adsorption treatment is performed, or a combination in which these appropriate treatments are performed in the same tank can be employed.

次に、一槽式の設備でハイドロタルサイトを利用し、フッ素含有排水からフッ素を除去して浄化する第２実施形態の排水浄化処理について説明する。   Next, the waste water purification process of the second embodiment in which hydrotalcite is used in one tank type equipment to remove and purify fluorine from fluorine-containing waste water will be described.

第２実施形態の排水浄化処理は、図２に示すように、フッ素を含有する排水を反応凝集沈殿槽５に導入し、反応凝集沈殿槽５にアルカリ又は酸のｐＨ調整剤を添加して、フッ素含有排水を所定のｐＨ、例えばｐＨ６程度に調整する。反応凝集沈殿槽５内のｐＨを調整したフッ素含有排水に塩化カルシウム（ＣａＣｌ２）を添加し、フッ素含有排水中のフッ素イオン（Ｆ−）と塩化カルシウムを反応させ、Ｃａ２＋＋２Ｆ−→ＣａＦ２ の反応によりフッ化カルシウム（ＣａＦ２）を生成する。 As shown in FIG. 2, the wastewater purification treatment of the second embodiment introduces fluorine-containing wastewater into the reaction coagulation sedimentation tank 5, adds an alkali or acid pH adjuster to the reaction coagulation sedimentation tank 5, The fluorine-containing waste water is adjusted to a predetermined pH, for example, about pH 6. Calcium chloride (CaCl 2 ) is added to the fluorine-containing wastewater whose pH in the reaction coagulation sedimentation tank 5 is adjusted, and the fluorine ions (F − ) and calcium chloride in the fluorine-containing wastewater are reacted to produce Ca 2+ + 2F − → CaF 2. To produce calcium fluoride (CaF 2 ).

更に、反応凝集沈殿槽５内にハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６ＣＯ３・４Ｈ２Ｏを添加し、フッ化カルシウム（ＣａＦ２）の生成後の排水中に残留するフッ素イオン（Ｆ−）をハイドロタルサイトに吸着させる。前記添加したハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６ＣＯ３・４Ｈ２Ｏの大部分は、前記フッ素イオン（Ｆ−）を層間に取り込こんで吸着し、フッ素イオンを吸着したハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６（Ｆ−１）２・４Ｈ２Ｏが生成される。 Further, hydrotalcite: Mg 6 Al 2 (OH) 16 CO 3 .4H 2 O is added to the reaction coagulation sedimentation tank 5 to leave the fluorine ions remaining in the waste water after the formation of calcium fluoride (CaF 2 ) ( F − ) is adsorbed on hydrotalcite. Most of the added hydrotalcite: Mg 6 Al 2 (OH) 16 CO 3 .4H 2 O is a hydrotalum in which the fluorine ions (F − ) are taken in and adsorbed between the layers, and the fluorine ions are adsorbed. Site: Mg 6 Al 2 (OH) 16 (F −1 ) 2 .4H 2 O is generated.

その後、反応凝集沈殿槽５に硫酸バンドやＰＡＣ等の凝集剤を添加して、フッ化カルシウム（ＣａＦ２）、及びフッ素を吸着したハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６（Ｆ−１）２・４Ｈ２Ｏ、及びフッ素を吸着できなかったハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６（Ｆ−１）２・４Ｈ２Ｏを凝集し、これらを含む汚泥を沈殿させる。沈殿した汚泥は反応凝集沈殿槽５から脱水機６に導出され、脱水機６で汚泥を脱水し、脱水ケーキとして排出すると共に、汚泥を除去して得られる処理水は系外に排出される。 Then, a hydrotalcite: Mg 6 Al 2 (OH) 16 (F −1 ) in which a flocculant such as a sulfate band or PAC is added to the reaction coagulation sedimentation tank 5 to adsorb calcium fluoride (CaF 2 ) and fluorine. ) 2 · 4H 2 O, and hydrotalcite could not adsorb fluorine: Mg 6 Al 2 (OH) 16 (F -1) agglomerating 2 · 4H 2 O, precipitating the sludge containing them. The precipitated sludge is led out from the reaction coagulation sedimentation tank 5 to the dehydrator 6, and the sludge is dehydrated by the dehydrator 6 and discharged as a dehydrated cake, and the treated water obtained by removing the sludge is discharged out of the system.

上記第２実施形態の排水浄化処理は、一基の反応凝集沈殿槽５と一基の脱水機６でフッ素含有排水からフッ素を除去し、小さな設備投資により低コストで、且つ省スペースでフッ素を除去することができる。更に、フッ化カルシウムの生成後に残留するフッ素イオンをハイドロタルサイトで吸着することにより、効率的にフッ素濃度が非常に低い処理水とすることができると共に、塩化カルシウム等や凝集剤を多量に用いる必要が無くなる。   The wastewater purification treatment of the second embodiment is to remove fluorine from fluorine-containing wastewater with a single reaction coagulation sedimentation tank 5 and a single dehydrator 6, and to save fluorine with a small capital investment at low cost and in a space-saving manner. Can be removed. Furthermore, by adsorbing the fluorine ions remaining after the formation of calcium fluoride with hydrotalcite, it is possible to efficiently make treated water with a very low fluorine concentration and to use a large amount of calcium chloride or a flocculant. There is no need.

尚、上記第２実施形態の排水浄化処理では、同一の反応凝集沈殿槽５に於いて、ｐＨ調整処理、塩化カルシウムとの反応によるフッ化カルシウムの生成処理、ハイドロタルサイトによるフッ素イオンの吸着処理、凝集処理、沈殿処理を行う構成としたが、第１実施形態の変形例等を適宜第２実施形態に用いることが可能であり、例えばｐＨ調整槽、フッ化カルシウムを生成する反応槽、フッ素イオンの吸着処理を行う反応槽、凝集槽、沈殿槽で各処理を行う構成、或いはこれらの適宜の処理の組み合わせを同一槽で行う構成、或いはフッ化カルシウムの生成処理の後に凝集や沈殿を行う槽を付加する構成等とすることが可能である。   In the wastewater purification treatment of the second embodiment, in the same reaction coagulation sedimentation tank 5, pH adjustment treatment, calcium fluoride production treatment by reaction with calcium chloride, fluoride ion adsorption treatment by hydrotalcite However, the modification of the first embodiment can be appropriately used in the second embodiment. For example, a pH adjustment tank, a reaction tank for generating calcium fluoride, fluorine A structure in which each treatment is performed in a reaction tank, an agglomeration tank, and a precipitation tank for performing ion adsorption treatment, or a structure in which these appropriate treatments are combined in the same tank, or agglomeration and precipitation are performed after the calcium fluoride production treatment It is possible to adopt a configuration in which a tank is added.

次に、上記第１実施形態の排水浄化処理過程に対応する、ハイドロタルサイトのフッ素の吸着、脱離、再吸着の模擬試験及びその結果について説明する。   Next, simulation tests and results of hydrotalcite fluorine adsorption, desorption, and resorption corresponding to the wastewater purification process of the first embodiment will be described.

先ず、ハイドロタルサイトのフッ素吸着試験では、約０．１ｍｏｌ／Ｌのフッ化カリウム溶液１Ｌ（イオンクロマトグラフィーによるフッ素含有量実測値：１８５０．０ｍｇ／Ｌ）を準備し、そこにハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６ＣＯ３・４Ｈ２Ｏを１０ｇ添加して、ＨＣｌを用いて溶液のｐＨを６前後に調整しながら１時間攪拌した。前記攪拌後に、その懸濁液を濾過し、残存した固相Ｋ１を定温乾燥器にて５０℃で乾燥させた。 First, in the hydrotalcite fluorine adsorption test, about 1 mol / L of potassium fluoride solution 1 L (measured fluorine content by ion chromatography: 1850.0 mg / L) was prepared, and hydrotalcite: 10 g of Mg 6 Al 2 (OH) 16 CO 3 .4H 2 O was added, and the mixture was stirred for 1 hour while adjusting the pH of the solution to around 6 using HCl. After the stirring, the suspension was filtered, and the remaining solid phase K1 was dried at 50 ° C. in a constant temperature dryer.

前記濾過による濾液Ｒ１のフッ素含有量をイオンクロマトグラフィーにより測定したところ、２３１．０ｍｇ／Ｌであり、添加したハイドロタルサイト１０ｇは１８５０．０−２３１．０＝１６１９．０ｍｇ／Ｌのフッ素イオンを吸着し、添加したハイドロタルサイト１ｇ当たりのフッ素吸着量は１６１．９ｍｇ／ｇであった（後記表２、(1)参照）。残存した固相Ｋ１は、フッ素を吸着したハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６（Ｆ−１）２・４Ｈ２Ｏと、通常のハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６ＣＯ３・４Ｈ２Ｏで構成される。 When the fluorine content of the filtrate R1 obtained by the filtration was measured by ion chromatography, it was 231.0 mg / L, and 10 g of the added hydrotalcite contained 1850.0-231.0 = 1619.0 mg / L of fluorine ions. The amount of fluorine adsorbed per 1 g of hydrotalcite adsorbed and added was 161.9 mg / g (see Table 2, (1) below). The remaining solid phase K1 is composed of hydrotalcite adsorbed with fluorine: Mg 6 Al 2 (OH) 16 (F −1 ) 2 .4H 2 O and normal hydrotalcite: Mg 6 Al 2 (OH) 16 CO. consisting of 3 · 4H 2 O.

次いで、フッ素を吸着したハイドロタルサイトのフッ素脱離試験では、先ず、ＮａＯＨを用い、それぞれｐＨを９、１０、１１に調節したＮａＯＨ溶液を各々５００ｍＬずつビーカーに準備し、固液比が１ｇ／Ｌになるようにして、各ビーカーにフッ素を吸着したハイドロタルサイトを含む固相Ｋ１を５００ｍｇずつ添加し、ＮａＯＨを用いてｐＨをそれぞれ９、１０、１１に維持するように調整しながら攪拌し、５分、１０分、１５分、３０分、６０分の攪拌時間毎にそれぞれ濾過を行った。   Next, in the fluorine desorption test of hydrotalcite that adsorbed fluorine, first, NaOH was used and 500 mL each of NaOH solutions adjusted to pH 9, 10, and 11 were prepared in a beaker, and the solid-liquid ratio was 1 g / Add 500 mg each of solid phase K1 containing hydrotalcite adsorbing fluorine to each beaker, and stir while adjusting the pH to be maintained at 9, 10 and 11 with NaOH, respectively. Filtration was performed every 5 minutes, 10 minutes, 15 minutes, 30 minutes, and 60 minutes of stirring time.

前記濾過による濾液Ｒ２のフッ素含有量を測定して得たフッ素脱離量と攪拌時間の関係を図３のグラフに示す。図３のグラフは、ｐＨ９、１０、１１の各ビーカーとも、全般的にｐＨが高ければ高い程、又、攪拌時間が長ければ長い程、フッ素の脱離量が増加することを示しており、例えばｐＨ９の５分攪拌では固相Ｋ：１ｇ当たりでフッ素：４４．２ｍｇ／ｇ、ｐＨ１１の６０分攪拌では固相Ｋ：１ｇ当たりでフッ素：１３２．０ｍｇが脱離した。尚、各ｐＨ９、１０、１１の攪拌時間６０分の場合のＦ脱離量を後記表２、(2)に示し、又、攪拌時間６０分の場合に於ける脱離後の固相を固相Ｋ２とする。   The relationship between the fluorine desorption amount obtained by measuring the fluorine content of the filtrate R2 by filtration and the stirring time is shown in the graph of FIG. The graph of FIG. 3 shows that the higher the pH as a whole and the longer the stirring time, the greater the amount of desorption of fluorine in each of the beakers of pH 9, 10, and 11. For example, in the case of stirring at pH 9 for 5 minutes, fluorine: 44.2 mg / g per 1 g of solid phase K was released, and in the case of stirring at pH 11 for 60 minutes, fluorine: 132.0 mg was released per 1 g of solid phase K. The amounts of F desorption when the stirring time is 60 minutes for each pH 9, 10, and 11 are shown in Table 2 (2) below, and the solid phase after desorption when the stirring time is 60 minutes is fixed. Let it be phase K2.

その後、ハイドロタルサイトのフッ素再吸着試験では、上記ハイドロタルサイトのフッ素吸着試験と基本的に同様の試験方法を行い、先ず、ｐＨ９、１０、１１のそれぞれに対応させ、約０．１ｍｏｌ／Ｌのフッ化カリウム溶液１Ｌ（イオンクロマトグラフィーによるフッ素含有量実測値：１８５０．０ｍｇ／Ｌ）を準備し、試料として脱離試験の攪拌時間６０分により濾過して得られたｐＨ９、１０、１１のそれぞれの固相Ｋ２を１０ｇ／Ｌの割合で添加し（後記表２、(2)参照）、ＨＣｌを用いて各溶液のｐＨを６前後に調整しながら１時間攪拌した。その後、メンブランフィルター（０．２μｍ）で固液分離を行って濾過し、液相の濾液Ｒ３と固相Ｋ３にし、分析を行った。   Thereafter, in the hydrotalcite fluorine resorption test, a test method basically similar to that of the hydrotalcite fluorine adsorption test is performed. First, it is made to correspond to each of pH 9, 10 and 11, and about 0.1 mol / L. Of potassium fluoride solution 1L (actually measured fluorine content by ion chromatography: 1850.0 mg / L) of pH 9, 10, and 11 obtained by filtering with a stirring time of 60 minutes as a sample in a desorption test. Each solid phase K2 was added at a rate of 10 g / L (see Table 2, (2) below), and stirred for 1 hour while adjusting the pH of each solution to around 6 using HCl. Thereafter, solid-liquid separation was performed using a membrane filter (0.2 μm), followed by filtration to obtain a liquid-phase filtrate R3 and a solid-phase K3 for analysis.

その結果を表１及び図４に示す。表１は、固相Ｋ２を添加する前の約０．１ｍｏｌ／Ｌのフッ化カリウム溶液１Ｌ当たりに於けるフッ素含有量：１８５０ｍｇ／Ｌに対する、ｐＨ９、１０、１１の各固相Ｋ２によるフッ素再吸着後の濾液Ｒ３のフッ素含有量（濾液：Ｆ）、固相Ｋ３のフッ素吸着量（固相：Ｆ）、及び固相Ｋ３の１ｇ当たりのフッ素吸着量を示し、図４は各ｐＨ９、１０、１１に於ける固相Ｋ３の１ｇ当たりのフッ素吸着量を示している。固相Ｋ３は、フッ素を吸着したハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６（Ｆ−１）２・４Ｈ２Ｏ、或いはフッ素を吸着したハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６（Ｆ−１）２・４Ｈ２Ｏ及び通常のハイドロタルサイト：Ｍｇ６Ａｌ２（ＯＨ）１６ＣＯ３・４Ｈ２Ｏで構成される。 The results are shown in Table 1 and FIG. Table 1 shows that the fluorine content per 1 L of potassium fluoride solution of about 0.1 mol / L before the addition of solid phase K2: The fluorine content (filtrate: F) of the filtrate R3 after adsorption, the fluorine adsorption amount of the solid phase K3 (solid phase: F), and the fluorine adsorption amount per gram of the solid phase K3 are shown in FIG. , 11 shows the amount of fluorine adsorbed per 1 g of the solid phase K3. The solid phase K3 is composed of hydrotalcite adsorbed with fluorine: Mg 6 Al 2 (OH) 16 (F −1 ) 2 .4H 2 O or hydrotalcite adsorbed with fluorine: Mg 6 Al 2 (OH) 16 ( F -1) 2 · 4H 2 O and normal hydrotalcite: Mg 6 Al 2 (OH) consists of 16 CO 3 · 4H 2 O.

Figure 2005193167
Figure 2005193167

そして、上記フッ素の吸着、脱離、再吸着の模擬試験により、前記各ｐＨ９、１０、１１のフッ素再吸着後に於けるフッ素吸着量を表２に示す。表２の再吸着後のフッ素吸着量は(1)の吸着試験によるフッ素吸着量から(2)のフッ素脱離試験のフッ素脱離量を減算し、(3)の再吸着試験によるフッ素吸着量を加算した数値である。   Table 2 shows the amount of fluorine adsorbed after the fluorine re-adsorption at each pH of 9, 10, and 11 by the above-described simulation test of fluorine adsorption, desorption, and re-adsorption. The amount of fluorine adsorbed after resorption in Table 2 is obtained by subtracting the amount of fluorine desorption from the fluorine desorption test in (2) from the amount of fluorine adsorption from the adsorption test in (1), and the amount of fluorine adsorption from the resorption test in (3). It is a numerical value obtained by adding.

Figure 2005193167
Figure 2005193167

表２が示すように、フッ素脱離時のｐＨが９、１０、１１へと高くなる程、フッ素の脱離量は増加するが、フッ素の再吸着時には脱離時のｐＨが９、１０、１１へと高くなる程、フッ素の吸着量は低下しており、その原因としては、例えば脱離時のアルカリの程度が異なるとハイドロタルサイトの層間に入るものがＯＨ−、ＣＯ３２−と異なるものになること等が考えられる。また、ｐＨ１１ではフッ素の再吸着時の吸着量が脱離時の脱離量より低下しているのに対し、ｐＨ９、１０ではフッ素の再吸着時の吸着量が脱離時の脱離量より多くなっており、これは(1)の吸着試験後のハイドロタルサイトの層間にはフッ素を吸着する余裕があったためと考えられる。 As Table 2 shows, the higher the pH at fluorine desorption, the higher the amount of fluorine desorption, the greater the amount of fluorine desorption, but at the time of fluorine resorption, the pH at desorption is 9, 10, The amount of adsorption of fluorine decreases as the value increases to 11, and the cause thereof is, for example, that when the degree of alkali at the time of desorption is different, what enters between the layers of hydrotalcite is different from OH − and CO 3 2−. It can be considered something. In addition, at pH 11, the adsorption amount at the time of fluorine re-adsorption is lower than the desorption amount at the time of desorption, whereas at pH 9, 10, the adsorption amount at fluorine re-adsorption is less than the desorption amount at the time of desorption. This is thought to be due to the fact that there was room for fluorine adsorption between the hydrotalcite layers after the adsorption test of (1).

更に、再吸着後の脱離した際に、その脱離割合が表２、(2)の脱離試験の脱離割合と同等と仮定した場合のフッ素脱離量を表３に示す。   Furthermore, when desorbing after re-adsorption, Table 3 shows the amount of fluorine desorption when the desorption ratio is assumed to be equivalent to the desorption ratio in the desorption test of (2).

Figure 2005193167
Figure 2005193167

表２、表３のフッ素吸着量やフッ素脱離量が示すように、ｐＨ９の場合には、再吸着する際の吸着量が多いが脱離量が少なくなるため、脱離と再吸着でフッ素除去にハイドロタルサイトを繰り返して使用する際の再生効率が低くなり、ｐＨ１１の場合には、脱離量が多いが再吸着する際の吸着量が少なくなるため、同様にハイドロタルサイトの再生効率が低くなる。これに対し、ｐＨ１０の場合には、再吸着する際の吸着量と脱離量が共に多いため、脱離と再吸着でフッ素除去にハイドロタルサイトを繰り返して使用する際の再生効率が最も高くなる。また、ｐＨ１０前後はハイドロタルサイトの合成に最適なｐＨであるため、溶解度が低く、再生して使用する際にハイドロタルサイトのロスが少ない。かかる観点からもｐＨ１０前後の脱離は、再生効率の向上に寄与する。   As shown in Tables 2 and 3, the amount of fluorine adsorbed and the amount of fluorine desorbed show that when pH is 9, the amount of adsorption during re-adsorption is large but the amount of desorption is small, so desorption and re-adsorption cause fluorine. Regeneration efficiency when hydrotalcite is repeatedly used for removal is low, and in the case of pH 11, since the amount of desorption is large but the amount of adsorption at the time of re-adsorption is small, similarly, the regeneration efficiency of hydrotalcite Becomes lower. On the other hand, in the case of pH 10, since both the adsorption amount and the desorption amount at the time of re-adsorption are large, the regeneration efficiency when using hydrotalcite repeatedly for fluorine removal by desorption and re-adsorption is the highest. Become. Moreover, since pH around 10 is the optimum pH for the synthesis of hydrotalcite, the solubility is low, and there is little loss of hydrotalcite when regenerated and used. From this point of view, desorption at around pH 10 contributes to improvement in regeneration efficiency.

尚、上記再吸着試験でｐＨ調整にＨＣｌを添加した際に、固相Ｋ２：１ｇ当たり換算のＨＣｌ添加量は、ｐＨ９の再吸着の場合：７６６．７μＬ、ｐＨ１０の再吸着の場合：３８４．６μＬ、ｐＨ１１の再吸着の場合：４５８．３μＬであり、ハイドロタルサイトの再生効率が高いｐＨ１０で必要なＨＣｌ添加量は最も少なかった。これは、ｐＨ１０で脱離後のハイドロタルサイト或いは固相Ｋ２が層間に弱酸のＣＯ３２−を多く有するためと考えられ、ｐＨ１０の再生効率の高さを示している。 In addition, when HCl is added for pH adjustment in the above resorption test, the amount of HCl added per 1 g of solid phase K2 is 766.7 μL for pH 9 resorption, and 384. In the case of 6 μL and pH 11 re-adsorption: 458.3 μL, and the required amount of HCl added was the smallest at pH 10 where hydrotalcite regeneration efficiency was high. This is thought to be because hydrotalcite or solid phase K2 after desorption at pH 10 has a large amount of weak acid CO 3 2− between the layers, indicating high regeneration efficiency at pH 10.

本発明の排水浄化方法或いは浄化方法を用いることにより、例えば半導体工場や発電所等から排出されるフッ素含有排水からフッ素を除去して、フッ素含有排水を効率的に低フッ素濃度の処理水、例えば環境保護に鑑み定められている排出基準以下の処理水にすることができる。   By using the wastewater purification method or purification method of the present invention, fluorine is removed from fluorine-containing wastewater discharged from, for example, a semiconductor factory or power plant, and the fluorine-containing wastewater is efficiently treated with low fluorine concentration, for example, Treated water below the emission standard established in view of environmental protection.

第１実施形態の排水浄化処理の流れを示す説明図。Explanatory drawing which shows the flow of the waste water purification process of 1st Embodiment. 第２実施形態の排水浄化処理の流れを示す説明図。Explanatory drawing which shows the flow of the waste water purification process of 2nd Embodiment. 攪拌時間とハイドロタルサイトからのフッ素イオン脱離量との関係を示すグラフ。The graph which shows the relationship between stirring time and the amount of fluorine ion desorption from hydrotalcite. ｐＨ９、１０、１１でフッ素を脱離した各ハイドロタルサイトの再吸着でのフッ素吸着量を示すグラフ。The graph which shows the amount of fluorine adsorption in the re-adsorption of each hydrotalcite from which fluorine was desorbed at pH 9, 10, and 11.

符号の説明Explanation of symbols

１ １次反応凝集沈殿槽
２ ２次反応凝集沈殿槽
３ フッ素脱離槽
４、６ 脱水機
５ 反応凝集沈殿槽 DESCRIPTION OF SYMBOLS 1 Primary reaction coagulation sedimentation tank 2 Secondary reaction coagulation sedimentation tank 3 Fluorine desorption tank 4, 6 Dehydrator 5 Reaction coagulation sedimentation tank

Claims (6)

フッ素含有排水にカルシウム化合物を添加してフッ化カルシウムを生成する工程と、該フッ化カルシウム生成後の反応液を固液分離してフッ化カルシウムを除去する工程と、該フッ化カルシウム除去後の処理水のｐＨを調整し、ハイドロタルサイト類を添加してハイドロタルサイト類に残留するフッ素を吸着させる工程と、該吸着後の処理水を固液分離してフッ素吸着後のハイドロタルサイト類を除去する工程とを、少なくとも有することを特徴とする排水浄化方法。 A step of adding calcium compound to fluorine-containing wastewater to produce calcium fluoride, a step of removing the calcium fluoride by solid-liquid separation of the reaction solution after the production of calcium fluoride, and a step of removing the calcium fluoride Adjusting the pH of treated water, adding hydrotalcite to adsorb fluorine remaining in hydrotalcite, and hydrotalcite after fluorine adsorption by solid-liquid separation of the treated water after adsorption And a step of removing water at least. 前記除去したフッ素吸着後のハイドロタルサイト類に対してフッ素脱離処理を施す工程と、該フッ素脱離処理後のハイドロタルサイト類をフッ素吸着工程で再度添加する工程を有すると共に、該フッ化カルシウム生成前のフッ素含有排水に該フッ素脱離処理で生成されるフッ素含有水を合わせる工程を有することを特徴とする請求項１記載の排水浄化方法。 A step of subjecting the removed hydrotalcite after the adsorption of fluorine to a fluorine desorption treatment; a step of adding the hydrotalcite after the fluorine desorption treatment again in a fluorine adsorption step; The drainage purification method according to claim 1, further comprising a step of combining fluorine-containing water generated by the fluorine desorption treatment with fluorine-containing wastewater before calcium generation. 前記フッ素脱離処理工程が、前記フッ素吸着後のハイドロタルサイト類をｐＨが９＜ｐＨ＜１１の溶液中で攪拌してフッ素脱離処理を施すものであることを特徴とする請求項２記載の排水浄化方法。 3. The fluorine desorption treatment step, wherein the hydrotalcite after fluorine adsorption is stirred in a solution having a pH of 9 <pH <11 to perform the fluorine desorption treatment. Wastewater purification method. フッ素含有排水にカルシウム化合物を添加してフッ化カルシウムを生成する工程と、該フッ化カルシウム生成後の反応液にハイドロタルサイト類を添加してハイドロタルサイト類に残留するフッ素を吸着させる工程と、該吸着後の反応液を固液分離してフッ化カルシウム及びフッ素吸着後のハイドロタルサイト類を除去する工程とを、少なくとも有することを特徴とする排水浄化方法。 Adding calcium compounds to fluorine-containing wastewater to generate calcium fluoride, adding hydrotalcite to the reaction solution after the calcium fluoride is generated, and adsorbing fluorine remaining in the hydrotalcite; And a step of solid-liquid separation of the reaction liquid after adsorption to remove calcium fluoride and hydrotalcite after fluorine adsorption. 前記ハイドロタルサイト類がハイドロタルサイトであることを特徴とする請求項１、２、３又は４記載の排水浄化方法。 The drainage purification method according to claim 1, 2, 3, or 4, wherein the hydrotalcite is hydrotalcite. フッ素を含有する浄化対象にハイドロタルサイト類を添加してフッ素を吸着させる浄化方法に於いて、フッ素吸着後のハイドロタルサイト類を９＜ｐＨ＜１１の溶液中で攪拌してフッ素脱離処理を施し、該フッ素脱離処理後のハイドロタルサイト類を浄化対象に再度添加してフッ素を吸着させることを特徴とする浄化方法。 In a purification method in which hydrotalcite is added to a purification target containing fluorine to adsorb fluorine, the hydrotalcite after fluorine adsorption is stirred in a solution of 9 <pH <11 to remove fluorine. And a hydrotalcite after the fluorine desorption treatment is added again to the purification target to adsorb fluorine.
JP2004002597A 2004-01-08 2004-01-08 Drainage purification method and purification method Withdrawn JP2005193167A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2004002597A JP2005193167A (en) 2004-01-08 2004-01-08 Drainage purification method and purification method
PCT/JP2004/007315 WO2005066080A1 (en) 2004-01-08 2004-05-21 Method of cleaning wastewater and cleaning method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2004002597A JP2005193167A (en) 2004-01-08 2004-01-08 Drainage purification method and purification method

Publications (1)

Publication Number Publication Date
JP2005193167A true JP2005193167A (en) 2005-07-21

Family

ID=34747051

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2004002597A Withdrawn JP2005193167A (en) 2004-01-08 2004-01-08 Drainage purification method and purification method

Country Status (2)

Country Link
JP (1) JP2005193167A (en)
WO (1) WO2005066080A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007203135A (en) * 2006-01-31 2007-08-16 Japan Ecology Corp Treatment method of waste liquid containing boron fluoride ion
JP2007209886A (en) * 2006-02-09 2007-08-23 Bokuto Kasei Kogyo Kk Fluorine removing agent, and method and apparatus for treating drain containing fluorine using the agent
JP2007244954A (en) * 2006-03-14 2007-09-27 Kyowa Chem Ind Co Ltd Wastewater treatment agent, and method for reducing fluorine ion in wastewater
WO2008015784A1 (en) * 2006-07-31 2008-02-07 Jdc Corporation Hydrotalcite-like particulate material and method for production thereof
WO2008059618A1 (en) * 2006-11-17 2008-05-22 Jdc Corporation Liquid treating apparatus, and liquid treating method, using hydrotalcite-like granular substance
JP2011115772A (en) * 2009-10-26 2011-06-16 Toshiba Corp Method and apparatus for treating waste liquid
JP2013075260A (en) * 2011-09-30 2013-04-25 Mitsubishi Materials Corp Treatment method and treatment apparatus for removing fluorine and harmful substance
JP7249602B1 (en) 2021-11-22 2023-03-31 栗田工業株式会社 Method for regenerating carbonate-type layered double hydroxide, method for treating acidic exhaust gas, and facility for treating acidic exhaust gas

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103303996B (en) * 2013-04-02 2014-09-17 中国科学院生态环境研究中心 Application of activated aluminum oxide defluorination adsorbing material with different surface features
CN103708679B (en) * 2013-12-26 2015-05-20 浙江工商大学 Treatment process for fluorine chemical wastewater
CN104193028B (en) * 2014-06-16 2016-02-17 江苏永冠给排水设备有限公司 A kind of compound drinking water defluorination method
CN104591435B (en) * 2015-01-04 2016-08-17 北京潮白环保科技有限公司 A kind of processing method of industrial wastewater
CN107252675A (en) * 2017-08-11 2017-10-17 江苏海普功能材料有限公司 A kind of support type defluorinating agent and preparation method thereof
CN114592125B (en) * 2022-02-28 2023-05-02 中南大学 Mineralization and fluorine removal method for fluorine-containing acid system

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58214338A (en) * 1982-06-04 1983-12-13 Kyowa Chem Ind Co Ltd Composite adsorbent
JPS59157035A (en) * 1983-02-28 1984-09-06 Kyowa Chem Ind Co Ltd Removal of halogen component from organic compound containing halogen-containing catalyst
JP3334142B2 (en) * 1991-10-01 2002-10-15 栗田工業株式会社 Treatment method for fluorine-containing water

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007203135A (en) * 2006-01-31 2007-08-16 Japan Ecology Corp Treatment method of waste liquid containing boron fluoride ion
JP2007209886A (en) * 2006-02-09 2007-08-23 Bokuto Kasei Kogyo Kk Fluorine removing agent, and method and apparatus for treating drain containing fluorine using the agent
JP2007244954A (en) * 2006-03-14 2007-09-27 Kyowa Chem Ind Co Ltd Wastewater treatment agent, and method for reducing fluorine ion in wastewater
US9718698B2 (en) 2006-07-31 2017-08-01 Jdc Corporation Hydrotalcite-like particulate material and method for production thereof
JP5201680B2 (en) * 2006-07-31 2013-06-05 日本国土開発株式会社 Hydrotalcite-like granular material and method for producing the same
WO2008015784A1 (en) * 2006-07-31 2008-02-07 Jdc Corporation Hydrotalcite-like particulate material and method for production thereof
WO2008059618A1 (en) * 2006-11-17 2008-05-22 Jdc Corporation Liquid treating apparatus, and liquid treating method, using hydrotalcite-like granular substance
JP5363817B2 (en) * 2006-11-17 2013-12-11 日本国土開発株式会社 Liquid processing apparatus and liquid processing method using hydrotalcite-like granular material
JP2011115772A (en) * 2009-10-26 2011-06-16 Toshiba Corp Method and apparatus for treating waste liquid
JP2013075260A (en) * 2011-09-30 2013-04-25 Mitsubishi Materials Corp Treatment method and treatment apparatus for removing fluorine and harmful substance
JP7249602B1 (en) 2021-11-22 2023-03-31 栗田工業株式会社 Method for regenerating carbonate-type layered double hydroxide, method for treating acidic exhaust gas, and facility for treating acidic exhaust gas
WO2023089913A1 (en) * 2021-11-22 2023-05-25 栗田工業株式会社 Method for regenerating carbonate-type layered double hydroxide, acidic exhaust gas treatment method, and acidic exhaust gas treatment equipment
JP2023076288A (en) * 2021-11-22 2023-06-01 栗田工業株式会社 Regeneration method for carbonate type layered double hydroxide, acidic exhaust gas treatment method, and acidic exhaust gas treatment facility

Also Published As

Publication number Publication date
WO2005066080A1 (en) 2005-07-21

Similar Documents

Publication Publication Date Title
US9242878B2 (en) Heavy metal removal from waste streams
JP2005193167A (en) Drainage purification method and purification method
WO2000003952A1 (en) Method for treating a fluorine-containing waste water and treating apparatus
JP2010082546A (en) Water treatment apparatus and method
JP2007209886A (en) Fluorine removing agent, and method and apparatus for treating drain containing fluorine using the agent
JP4693128B2 (en) Phosphorus recovery method and phosphorus recovery system
CN110330164B (en) Method for recovering fluorine resource and sodium resource from alkaline high-salt high-fluorine wastewater
JP3600458B2 (en) Treatment of flue gas desulfurization wastewater
JP4631425B2 (en) Method and apparatus for treating fluorine-containing wastewater containing phosphoric acid
JP3319053B2 (en) Treatment method for fluoride-containing water
JP2003305458A (en) Method for treating fluorine-containing waste water
CA3066212A1 (en) Method of adsorbing an anion of interest from an aqueous solution
JP4350078B2 (en) Treatment method for fluorine-containing wastewater
JP2005324137A (en) Method for removing fluoride ion in wastewater
JP2008029985A (en) Apparatus for regenerating anion adsorbent and method of regenerating anion adsorbent using the same
JP2004000846A (en) Treatment method for fluorine-containing water
JP4164681B2 (en) How to recover phosphorus
JP4543482B2 (en) Fluorine-containing water treatment method
JP2010069413A (en) Organic waste water treatment method
JP6888798B2 (en) Boron removal method and boron removal device
JP2009220063A (en) Method for regenerating phosphorus adsorbent for treating waste water
JP3888534B2 (en) Treatment method for fluorine-containing wastewater
JPS6230596A (en) Method for treating fluorine in waste water
JP4640149B2 (en) Fluorine-containing water treatment method
JP2004216312A (en) Composite metal hydroxide containing water of crystallization and phosphorus-containing waste water treatment method using it

Legal Events

Date Code Title Description
A300 Application deemed to be withdrawn because no request for examination was validly filed

Free format text: JAPANESE INTERMEDIATE CODE: A300

Effective date: 20070403