JPH0947790A - Treatment of waste stack gas desulfurization effluent - Google Patents

Treatment of waste stack gas desulfurization effluent

Info

Publication number
JPH0947790A
JPH0947790A JP7219765A JP21976595A JPH0947790A JP H0947790 A JPH0947790 A JP H0947790A JP 7219765 A JP7219765 A JP 7219765A JP 21976595 A JP21976595 A JP 21976595A JP H0947790 A JPH0947790 A JP H0947790A
Authority
JP
Japan
Prior art keywords
flue gas
gas desulfurization
desulfurization wastewater
wastewater
effluent
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.)
Granted
Application number
JP7219765A
Other languages
Japanese (ja)
Other versions
JP3385137B2 (en
Inventor
Kazushige Kawamura
和茂 川村
Akito Ishige
明人 石毛
Masaru Takeda
大 武田
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.)
Chiyoda Corp
Chiyoda Chemical Engineering and Construction Co Ltd
Original Assignee
Chiyoda Corp
Chiyoda Chemical Engineering and Construction 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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=16740657&utm_source=***_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=JPH0947790(A) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Chiyoda Corp, Chiyoda Chemical Engineering and Construction Co Ltd filed Critical Chiyoda Corp
Priority to JP21976595A priority Critical patent/JP3385137B2/en
Publication of JPH0947790A publication Critical patent/JPH0947790A/en
Application granted granted Critical
Publication of JP3385137B2 publication Critical patent/JP3385137B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Landscapes

  • Removal Of Specific Substances (AREA)

Abstract

PROBLEM TO BE SOLVED: To remove an oxidizing material and selenium from a waste stack gas desulfurization effluent in one process by bringing at least one kind of metal selected from Fe, Mn, Ni and Cu into contact with the effluent to remove the oxidizing material and selenium in the effluent. SOLUTION: The device 10 is formed with a reaction tank 12 wherein an introduced waste stack gas desulfurization effluent is allowed to react with at least one kind of metal selected from Fe, Mn, Ni and Cu or the metal compds., a pH regulating tank 14 and a settling tank 16. The effluent is introduced into the reaction tank 12, the pH is regulated, and ferrous chloride, e.g. powdery, is added to the effluent. The oxidizing material in the effluent is reduced by the ferrous chloride, and sulfur peroxide, for example, is converted into sulfate ion. The pH of the effluent is then regulated in the tank 14 to form iron hydroxide, and the effluent is introduced into the setting tank 16 to settle the iron hydroxide. The selenium is entrained by the iron hydroxide, coprecipitated and separated from the effluent.

Description

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

【０００１】[0001]

【発明の属する技術分野】本発明は、排煙脱硫排水の処
理方法に関し、更に詳細には排煙脱硫排水から酸化性物
質及びセレン（Ｓｅ）を同時に効率良く除去する排煙脱
硫排水の処理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 flue gas desulfurization wastewater, and more particularly to a method for treating flue gas desulfurization wastewater which efficiently removes oxidizing substances and selenium (Se) from the flue gas desulfurization wastewater. It is about.

【０００２】[0002]

【従来の技術】排ガスから亜硫酸ガス等の硫黄酸化物を
除去するために、排ガスと吸収液とを気液接触させ、硫
黄酸化物を除去する湿式排煙脱硫法が多用されている。
湿式排煙脱硫方法は、大別すると、ジェットバブリング
反応槽等の反応槽を設け、反応槽に収容した吸収液中に
排ガスを導入して気液接触させる方式と、スプレー式吸
収塔を設け、吸収塔に導入される排ガス中に吸収液をス
プレーして気液接触させる方式とがある。その他、充填
塔を用いて気液接触させる方法もある。従来の湿式排煙
脱硫方法では、反応槽又は吸収塔（以下、反応槽等と言
う）の上流に除塵塔を設け、反応槽等に導入する前に除
塵塔で排ガスと冷却液とを接触させて予め排ガスの冷却
及び除塵を行う２塔式が採用されていたが、近年の反応
槽等の性能の向上の結果、除塵塔を省略した、一塔式の
いわゆるスート混合型排煙脱硫装置も多用されている。
また、従来の湿式排煙脱硫方法では、反応槽等の後段に
酸化塔を設け、そこで酸化処理を行っていたが、現在で
は、酸化を反応槽等で行う方式が一般的である。2. Description of the Related Art In order to remove sulfur oxides such as sulfur dioxide from exhaust gas, a wet flue gas desulfurization method is widely used in which the exhaust gas is brought into gas-liquid contact with an absorbent to remove sulfur oxides.
The wet flue gas desulfurization method is roughly divided into a reaction tank such as a jet bubbling reaction tank, a method of introducing exhaust gas into the absorption liquid housed in the reaction tank for gas-liquid contact, and a spray absorption tower. There is a system in which the absorbing liquid is sprayed into the exhaust gas introduced into the absorption tower and brought into gas-liquid contact. In addition, there is also a method of contacting gas and liquid using a packed tower. In the conventional wet flue gas desulfurization method, a dust removing tower is provided upstream of a reaction tank or an absorption tower (hereinafter referred to as a reaction tank, etc.), and the exhaust gas and the cooling liquid are brought into contact with each other in the dust removing tower before being introduced into the reaction tank or the like. The two-column type that cools exhaust gas and removes dust has been adopted in advance, but as a result of improvements in the performance of reaction tanks in recent years, so-called soot-mixed flue gas desulfurization equipment that does not have a dust-removing tower is also used. It is used a lot.
Further, in the conventional wet flue gas desulfurization method, an oxidation tower was provided in the latter stage of the reaction tank and the like, and the oxidation treatment was carried out there, but at present, the method of carrying out the oxidation in the reaction tank or the like is general.

【０００３】使用される吸収液は、硫黄酸化物を固定化
する吸収剤を水に溶解及び／又は懸濁させた液で、一般
にはカルシウム化合物系の吸収剤、例えば石灰石を水に
溶解及び／又は懸濁させたスラリ状水溶液を使用する。
排ガス中の硫黄酸化物は、ジェットバブリング反応槽等
の反応槽に収容された吸収液或いはスプレー式吸収塔内
でスプレーされた吸収液と気液接触して吸収液に化学吸
収及び／又は物理吸収され、水、酸素及び石灰石と反応
し、石膏となって排ガスから除去される。生じた石膏
は、粒子となって晶析し、吸収液中に浮遊する。The absorption liquid used is a liquid obtained by dissolving and / or suspending an absorbent for immobilizing sulfur oxides in water. Generally, a calcium compound-based absorbent such as limestone is dissolved and / or dissolved in water. Alternatively, a suspended aqueous slurry is used.
Sulfur oxides in exhaust gas come into gas-liquid contact with the absorption liquid stored in a reaction tank such as a jet bubbling reaction tank or the absorption liquid sprayed in a spray type absorption tower to chemically and / or physically absorb the absorption liquid. It reacts with water, oxygen and limestone to form gypsum, which is removed from the exhaust gas. The generated gypsum crystallizes as particles and floats in the absorbing liquid.

【０００４】晶析した石膏を濃厚に含有するスラリは、
石膏分離装置に送液され、そこで石膏が分離される。図
３は、従来の石膏分離装置１の模式的フローシートであ
る。従来の石膏分離装置１では、図３に示すように、反
応槽等２の底部から排出ポンプ４により排出され、固液
分離装置又は石膏脱水機６に送液され、そこで石膏がス
ラリから分離される。次いで、母液の一部は、石灰石粉
末が添加された後、吸収剤スラリとして反応槽等２に戻
されて再び排ガスと気液接触し、母液の一部は、排煙脱
硫排水として排水処理装置８へ送られ、浄化処理された
後、河川等に放流される。浄化処理する排水処理装置８
は、処理排水を河川等に放流できる程度に排煙脱硫排水
を浄化する装置を言う。排水処理装置は、湿式排煙脱硫
装置に付属した装置である場合もあるし、また公共の排
水処理装置である場合もある。A slurry containing a large amount of crystallized gypsum is
The gypsum is sent to a gypsum separator, where the gypsum is separated. FIG. 3 is a schematic flow sheet of the conventional gypsum separating apparatus 1. In the conventional gypsum separating apparatus 1, as shown in FIG. 3, the gypsum is separated from the slurry by being discharged from the bottom of the reaction tank 2 by the discharge pump 4 and sent to the solid-liquid separator or the gypsum dehydrator 6. It Next, a part of the mother liquor is added to the limestone powder and then returned to the reaction tank 2 or the like as an absorbent slurry to come into gas-liquid contact with the exhaust gas again, and a part of the mother liquor is treated as a flue gas desulfurization wastewater to a waste water treatment device. It is sent to No. 8 for purification treatment and then discharged to rivers. Wastewater treatment device 8 for purification treatment
Is a device that purifies the flue gas desulfurization wastewater to the extent that the treated wastewater can be discharged into a river or the like. The wastewater treatment device may be a device attached to the wet flue gas desulfurization device, or may be a public wastewater treatment device.

【０００５】ところで、最近、湿式排煙脱硫装置から送
液される排煙脱硫排水に吸着処理及び／又は生物学的処
理を施して所定の水質に排煙脱硫排水を処理する排水処
理装置において、その性能の劣化が予想以上に速くしか
も急激に進行することが問題にされており、その原因が
湿式排煙脱硫装置から送液される排煙脱硫排水の水質に
あることが判った。ここで、吸着処理とは、吸着剤によ
る吸着のみならず、イオン交換樹脂によるイオン交換処
理をも含む概念であり、生物学的処理とは、硝化菌、脱
窒素菌等を使用して生物学的に排水処理することであ
る。その問題とは、例えば排煙脱硫排水の脱窒素工程で
利用されている硝化菌及び脱窒素菌の成長が阻害され、
そのために排水処理装置から放流される処理水の窒素量
が増大していることであり、また排煙脱硫排水中のＣＯ
Ｄを吸着させる吸着剤として使用されている有機物吸着
樹脂の劣化が予想外に速いことである。さらに、ホウ
素、フッ素を除去する樹脂についても同様の現象が起こ
る。By the way, recently, in a wastewater treatment equipment for treating the flue gas desulfurization wastewater to a predetermined water quality by subjecting the flue gas desulfurization wastewater sent from the wet flue gas desulfurization equipment to adsorption treatment and / or biological treatment, It has been known that the deterioration of the performance proceeds more rapidly and rapidly than expected, and the cause is the quality of the flue gas desulfurization wastewater sent from the wet flue gas desulfurization equipment. Here, the adsorption treatment is a concept that includes not only adsorption by an adsorbent but also ion exchange treatment by an ion exchange resin, and biological treatment means biological treatment using nitrifying bacteria, denitrifying bacteria, etc. Wastewater treatment. The problem is, for example, the growth of nitrifying bacteria and denitrifying bacteria used in the denitrification process of flue gas desulfurization wastewater is inhibited,
Therefore, the amount of nitrogen in the treated water discharged from the wastewater treatment equipment is increasing, and the CO in the flue gas desulfurization wastewater is increased.
The deterioration of the organic substance adsorption resin used as an adsorbent for adsorbing D is unexpectedly fast. Furthermore, the same phenomenon occurs with a resin that removes boron and fluorine.

【０００６】本発明者らは、前述した排水処理装置の性
能低下について研究した結果、湿式排煙脱硫装置から排
出される排煙脱硫排水に含まれている酸化性物質の濃度
が高いことに主としてその原因があることを突き止め
た。ここで、酸化性物質とは、排煙脱硫排水に含まれて
いる酸化能を有する物質を意味し、その中には硫黄過酸
化物、例えばＳ2 ０8 2-も含まれている。酸化性物質
は、ＪＩＳ Ｋ０１０２ 工業排水試験方法のジエチル
−Ｐ−フェニレンジアミン比色法において発色時間を長
くしたこと以外それに準じて操作し、安定した発色状態
になった時の比色による塩素換算値で定量できる成分で
ある。以下、この方法をＤＰＤ法と言う。また、例えば
イオンクロマトグラフィを使用することにより、酸化性
物質のうち硫黄過酸化物のみを定量することもできる。As a result of research on the performance deterioration of the above-mentioned wastewater treatment equipment, the present inventors mainly found that the concentration of oxidizing substances contained in the flue gas desulfurization wastewater discharged from the wet flue gas desulfurization equipment was high. I found out the cause. Here, the oxidizing agent means a substance having an oxidizing ability that is included in the waste water of flue gas desulfurization, among which sulfur peroxides, for example contained S 2 0 8 2-even. Oxidizing substances were operated according to JIS K0102 industrial wastewater test method in the diethyl-P-phenylenediamine colorimetric method except that the coloring time was lengthened, and the chlorine conversion value by colorimetry when a stable coloring state was obtained. It is a component that can be quantified by. Hereinafter, this method is called a DPD method. Further, for example, by using ion chromatography, it is possible to quantify only sulfur peroxide among oxidizing substances.

【０００７】また、排煙脱硫排水中には、微量のセレン
（以下、Ｓｅと元素記号で呼ぶ）が含まれている。それ
は、排ガス中に含まれていた微量のセレン化合物が湿式
排煙脱硫装置で吸収液と気液接触して吸収液に懸濁し、
またその一部は、セレン酸、亜セレン酸などのＳｅ化合
物として吸収液に溶解し、それが排煙脱硫排水に含まれ
て流出したものである。環境問題の関心の高まりと共
に、Ｓｅの流出を確実に防止することが要請され、Ｓｅ
の排出基準が設定され、今後も厳しいものになると予想
される。The flue gas desulfurization wastewater contains a trace amount of selenium (hereinafter referred to as Se by the element symbol). It is because the trace amount of selenium compound contained in the exhaust gas comes into gas-liquid contact with the absorbing liquid in the wet flue gas desulfurization device and is suspended in the absorbing liquid.
Further, a part thereof is dissolved in the absorbing solution as an Se compound such as selenic acid and selenious acid, and is contained in the flue gas desulfurization wastewater and flows out. With increasing concern about environmental issues, it is required to prevent Se from leaking out.
Emission standards have been set and are expected to become stricter in the future.

【０００８】[0008]

【発明が解決しようとする課題】ところで、排煙脱硫排
水から酸化性物質を除去する方法及び排煙脱硫排水から
Ｓｅを除去する方法は、従来からそれぞれ開発され、か
つ提案されている。しかし、従来の方法は、それぞれ個
別に排煙脱硫排水を処理して酸化性物質又はＳｅを除去
する方法である。そのために、従来の方法を適用して排
煙脱硫排水から酸化性物質及びＳｅの双方を除去しよう
とすると、処理プロセスが複雑になり、操作が煩雑にな
ると共に設備費及び運転費が嵩むと言う問題があった。By the way, a method for removing oxidizing substances from flue gas desulfurization wastewater and a method for removing Se from flue gas desulfurization wastewater have been developed and proposed, respectively. However, the conventional method is a method of individually treating the flue gas desulfurization wastewater to remove the oxidizing substances or Se. Therefore, if it is attempted to remove both oxidizing substances and Se from the flue gas desulfurization wastewater by applying the conventional method, the treatment process becomes complicated, the operation becomes complicated, and the equipment cost and the operating cost increase. There was a problem.

【０００９】そこで、本発明の目的は、一つのプロセス
で排煙脱硫排水から酸化性物質とセレン（Ｓｅ）の双方
を除去できる方法を提供することである。Therefore, an object of the present invention is to provide a method capable of removing both oxidizing substances and selenium (Se) from flue gas desulfurization wastewater in one process.

【００１０】[0010]

【課題を解決するための手段】本発明者らは、排煙脱硫
排水の処理方法を開発するための種々の実験の過程で、
次に示す実験例１で説明するように、特定の条件の下で
酸化性物質とＳｅとを合わせて除去できることを見い出
し、本発明方法を完成するに到った。尚、本明細書で
は、排煙脱硫排水とは、湿式又は乾式、スート混合式、
スート分離式又は同時酸化方式にかかわらず、排煙脱硫
装置より排出されて排水処理装置（排水処理装置は、湿
式排煙脱硫装置の一部として設けられている装置でも良
く、また湿式排煙脱硫装置とは独立して設けられている
装置でも良い。）に送水され、そこで処理される排水を
言う。更に言えば、排煙脱硫排水は、排煙脱硫装置より
排出される排水の全てを含む概念で、例えば、吸収液と
同一組成の排水、即ち石灰石等の亜硫酸ガス脱硫剤及び
石膏等の亜硫酸ガスを固定した生成物を含む吸収液を排
出した排水、その吸収液を固液分離した後の母液、更に
は除塵塔から排出された排水、その排水を固液分離した
後の母液、また定期的に排水される定期点検時の排水や
各種洗浄水も含む概念である。従って、排煙脱硫排水
は、亜硫酸、脱硫助剤を含むこともある。In the course of various experiments for developing a method for treating flue gas desulfurization wastewater, the present inventors have
As described in Experimental Example 1 below, it was found that the oxidizing substance and Se can be removed together under specific conditions, and the method of the present invention was completed. In the present specification, the flue gas desulfurization wastewater is a wet or dry type, soot mixing type,
Regardless of whether it is a soot separation system or a simultaneous oxidation system, wastewater treatment equipment that is discharged from the flue gas desulfurization equipment (the wastewater treatment equipment may be equipment provided as part of the wet flue gas desulfurization equipment, or wet flue gas desulfurization equipment) It may be a device provided independently of the device.) Wastewater that is sent to and treated there. Furthermore, the flue gas desulfurization wastewater is a concept that includes all the wastewater discharged from the flue gas desulfurization device.For example, wastewater having the same composition as the absorbing liquid, that is, a sulfurous acid gas desulfurizing agent such as limestone and a sulfurous acid gas such as gypsum. Wastewater that has discharged the absorption liquid containing the product with fixed, mother liquor after solid-liquid separation of the absorption liquid, wastewater discharged from the dust removal tower, mother liquor after solid-liquid separation of the wastewater, and also regularly It is a concept that also includes drainage water at the time of periodic inspection and various cleaning water. Therefore, the flue gas desulfurization wastewater may contain sulfurous acid and desulfurization aid.

【００１１】実験例１ ２〜３mm径の球状の純度９９％の鉄を重量４４０ｇ用意
し、嵩容積１００ccの固定床の形態で充填して実験用反
応槽を作製した。石灰石を吸収剤として使用したスート
混合型湿式排煙脱硫装置でもって石炭焚排ガスを処理し
て得た排煙脱硫排水を原水として実験用反応槽に通水す
ることにした。原水の酸化性物質濃度及びＳｅ濃度は、
原水採取時期の湿式排煙脱硫装置の運転条件によって異
なり、本実験に使用した原水の酸化性物質濃度は１５〜
１８mg-cl/L −原水（塩素換算値）、Ｓｅ濃度は０．６
mg/Lであった。また、原水のｐＨ及び温度は、それぞれ
３．５及び５０°C であった。次いで、図１に示す所定
の空塔速度（ＳＶ（１／ｈｒ））で原水を反応槽に通水
した。定常状態になったところで、反応槽出口の処理水
中の酸化性物質濃度及びＳｅ濃度を測定し、酸化性物質
及びＳｅの除去率をそれぞれ算出した。続いて、種々の
空塔速度で実験用反応槽に通水し、同じように酸化性物
質及びＳｅの除去率を算出し、その結果を図１に示し
た。なお、Ｓｅの除去率は排煙脱硫装置の運転条件によ
って変動することが確認された。 Experimental Example 1 440 g of spherical iron having a diameter of 2 to 3 mm and a purity of 99% was prepared and filled in the form of a fixed bed having a bulk volume of 100 cc to prepare an experimental reaction tank. Flue gas desulfurization wastewater obtained by treating coal-burning exhaust gas with a soot-mixing type wet flue gas desulfurization equipment using limestone as an absorbent was passed to the experimental reaction tank as raw water. The oxidant concentration and Se concentration of raw water are
Depending on the operating conditions of the wet flue gas desulfurizer at the time of raw water sampling, the concentration of oxidizing substances in the raw water used in this experiment was 15-
18mg-cl / L-raw water (chlorine conversion value), Se concentration is 0.6
It was mg / L. The pH and temperature of the raw water were 3.5 and 50 ° C, respectively. Then, raw water was passed through the reaction tank at a predetermined superficial velocity (SV (1 / hr)) shown in FIG. When the steady state was reached, the concentration of oxidizing substances and the concentration of Se in the treated water at the outlet of the reaction tank were measured, and the removal rates of the oxidizing substances and Se were calculated. Subsequently, water was passed through the experimental reaction tank at various superficial velocities, and the removal rates of the oxidizing substance and Se were calculated in the same manner, and the results are shown in FIG. It was confirmed that the Se removal rate varies depending on the operating conditions of the flue gas desulfurization apparatus.

【００１２】実験例２ 実験例１と同じ実験用反応槽と原水を使用し、ＳＶを６
〔１／Hr〕に設定し、原水のｐＨを種々に調整して、実
験を行い、表１の結果を得た。 Experimental Example 2 The same experimental reaction tank and raw water as in Experimental Example 1 were used, and the SV was 6
[1 / Hr] was set, the pH of the raw water was variously adjusted, experiments were conducted, and the results shown in Table 1 were obtained.

【表１】 [Table 1]

【００１３】実験例１の結果から、４０〔１／Hr〕以下
の空塔速度で、酸化性物質及びＳｅの除去率がそれぞれ
約１００％及び３５％以上になり、また、実験例２の結
果からｐＨの広い範囲で酸化性物質及びＳｅの高い除去
率を得ることができることが確認できた。From the results of Experimental Example 1, at superficial velocities of 40 [1 / Hr] or less, the removal rates of oxidizing substances and Se were about 100% and 35% or more, respectively. From this, it was confirmed that a high removal rate of oxidizing substances and Se can be obtained in a wide pH range.

【００１４】鉄に代えて、Ｍｎ、Ｎｉ及びＣｕの金属を
使用し、実験例１と同じ原水について酸化性物質とＳｅ
の除去実験を行ったところ、実験例１及び２と同じよう
な結果を得た。Metals of Mn, Ni and Cu were used in place of iron, and the same raw water as in Experimental Example 1 was mixed with an oxidizing substance and Se.
When the removal experiment was performed, the same results as in Experimental Examples 1 and 2 were obtained.

【００１５】上記知見に基づき、本発明の目的を達成す
るために、本発明に係る排煙脱硫排水の処理方法（以
下、第１発明方法と言う）は、排ガス中の硫黄酸化物を
除去する排煙脱硫装置から排出される排煙脱硫排水を処
理する方法であって、Ｆｅ、Ｍｎ、Ｎｉ及びＣｕから選
ばれた少なくとも１種類の金属を排煙脱硫排水に接触さ
せ、排煙脱硫排水中の酸化性物質及びセレン（Ｓｅ）を
除去することを特徴としている。Based on the above findings, in order to achieve the object of the present invention, the method for treating flue gas desulfurization wastewater according to the present invention (hereinafter referred to as the first invention method) removes sulfur oxides in exhaust gas. A method for treating flue gas desulfurization wastewater discharged from a flue gas desulfurization wastewater, comprising contacting at least one metal selected from Fe, Mn, Ni and Cu with the flue gas desulfurization wastewater The oxidizer and selenium (Se) are removed.

【００１６】実験例１及び実験例２から、ペルオキソニ
硫酸（Ｓ2 Ｏ8 2- ）を例にして、鉄（Ｆｅ）による酸化
性物質とＳｅの除去のメカニズムを説明する。尚、実際
的には、酸化性物質の主成分は、ペルオキソニ硫酸など
の硫黄過酸化物である。以下の反応式に示す反応が並列
で同時的に進行することにより、Ｓ2 Ｏ8 2- が硫酸イオ
ンに還元されて消滅し、Ｓｅは鉄金属から生成した鉄化
合物からなる沈殿物に随伴して沈殿し、例えば共沈の形
態で沈殿し、これによって原水中から除去される。ま
た、鉄金属の酸化還元反応により、原水のＳｅが共沈現
象等より沈殿し易いＳｅの形態、例えば亜セレン酸に転
化することにより、Ｓｅの除去率が向上している。ｐＨ
３．０以上の領域では、Ｆｅは、主として、次式（１）
から（７）に従って、酸化性物質を還元しつつ不溶性の
鉄水酸化物又は鉄酸化物などに転化し、沈殿する。From Experimental Example 1 and Experimental Example 2, the mechanism of removing the oxidizing substance and Se by iron (Fe) will be described by taking peroxodisulfate (S 2 O 8 2− ) as an example. Practically, the main component of the oxidizing substance is sulfur peroxide such as peroxodisulfuric acid. As the reactions shown in the following reaction formulas proceed in parallel and simultaneously, S 2 O 8 2− is reduced to sulfate ions and disappears, and Se is accompanied by a precipitate composed of an iron compound produced from iron metal. Precipitate, for example in the form of coprecipitation, by which it is removed from the raw water. Further, the removal rate of Se is improved by the conversion of Se in the raw water into a form of Se which is more likely to precipitate due to the coprecipitation phenomenon or the like, for example, selenious acid due to the redox reaction of iron metal. pH
In the region of 3.0 or more, Fe is mainly represented by the following formula (1)
According to (7) to (7), the oxidizable substance is reduced while being converted into insoluble iron hydroxide or iron oxide, and then precipitated.

【００１７】 Ｆｅ＋Ｓ2 Ｏ8 2- →Ｆｅ2+＋２ＳＯ4 2- （１） ２Ｆｅ2+＋Ｓ2 Ｏ8 2- →２Ｆｅ3+＋２ＳＯ4 2- （２） ２Ｆｅ3+＋Ｆｅ →３Ｆｅ2+ （３） Ｆｅ3+＋３ＯＨ- →Ｆｅ（ＯＨ）3 （４） Ｆｅ2+＋２ＯＨ- →Ｆｅ（ＯＨ）2 （５） Ｆｅ3+＋Ｏ2 →Ｆｅ2 Ｏ3 など （６） Ｆｅ2+＋Ｏ2 →ＦｅＯなど （７）Fe + S 2 O 8 2- → Fe 2+ + 2SO 4 2- (1) 2Fe 2+ + S 2 O 8 2- → 2Fe 3+ + 2SO 4 2- (2) 2Fe 3+ + Fe → 3Fe 2+ (3 ) Fe 3+ + 3OH − → Fe (OH) 3 (4) Fe 2+ + 2OH − → Fe (OH) 2 (5) Fe 3+ + O 2 → Fe 2 O 3 etc. (6) Fe 2+ + O 2 → FeO Etc. (7)

【００１８】Ｓｅは、以上の反応式（４）から（７）に
従って生じる鉄化合物からなる沈殿物に随伴して沈殿
し、例えば鉄化合物からなる沈殿物との共沈状態で沈殿
し、排煙脱硫排水から除去される。Se precipitates in association with a precipitate composed of an iron compound generated according to the above reaction formulas (4) to (7), for example, in a coprecipitation state with a precipitate composed of an iron compound, and smoke is emitted. Removed from desulfurization effluent.

【００１９】ｐＨ３．０以下の領域では、反応機構は明
確ではないが、ＦｅはＳ2 Ｏ8 2- （酸化性物質）と反応
して酸化性物質を還元し、かつＦｅは水素を発生しつつ
酸化され不溶性の鉄酸化物などに転化し、沈殿すると考
えられる。Ｓｅは、その時に生じる鉄酸化物等の鉄化合
物からなる沈殿物に随伴して沈殿し、例えば鉄化合物か
らなる沈殿物との共沈状態で沈殿し、排煙脱硫排水から
除去されると推定される。In the pH range of 3.0 or lower, the reaction mechanism is not clear, but Fe reacts with S 2 O 8 2− (oxidizing substance) to reduce the oxidizing substance, and Fe generates hydrogen. While being oxidized, it is considered to be converted to insoluble iron oxides and the like and precipitated. It is presumed that Se is precipitated along with a precipitate composed of an iron compound such as iron oxide generated at that time, for example, in a coprecipitation state with a precipitate composed of an iron compound, and is removed from flue gas desulfurization wastewater. To be done.

【００２０】Ｓｅを除去する場合、好適には、排煙脱硫
排水のｐＨを３から１０に調整する。それは、ｐＨが１
０以上では、式（５）による沈殿物生成に伴うＳｅ除去
効果が式（４）による効果より小さく、ｐＨが高いほ
ど、式（５）の寄与が式（４）より大きくなり、Ｓｅの
除去効果は大幅に低下するからである。また、Ｆｅ3+、
Ｓｅの水和状態などにより凝集、共沈効果が低下するの
で、Ｓｅの除去率は低下する傾向にある。以上のことか
ら、酸化性物質とＳｅとを除去する際に、Ｆｅを選択し
た場合には、排煙脱硫排水のｐＨを３．０以上が望まし
く、更に望ましくは３．０〜１０の範囲である。ｐＨの
調整は、Ｆｅに接触させている過程で行っても良く、ま
たその過程の前で行っても良い。When removing Se, the pH of the flue gas desulfurization wastewater is preferably adjusted to 3 to 10. It has a pH of 1
At 0 or more, the Se removal effect associated with the formation of the precipitate by the equation (5) is smaller than the effect by the equation (4), and the higher the pH, the larger the contribution of the equation (5) becomes than that of the equation (4), thus removing the Se. This is because the effect will be greatly reduced. In addition, Fe 3+ ,
Since the aggregation and co-precipitation effects are reduced due to the hydration state of Se, the removal rate of Se tends to decrease. From the above, when Fe is selected when removing the oxidizing substance and Se, the pH of the flue gas desulfurization effluent is preferably 3.0 or more, and more preferably in the range of 3.0 to 10. is there. The pH adjustment may be performed in the process of contacting with Fe, or may be performed before the process.

【００２１】また、鉄と接触している排煙脱硫排水中に
酸素含有気体、例えば空気を送入することにより、次の
反応式（８）及び反応式（３）、（６）、（７）に示す
ような反応によって、鉄化合物の生成、沈殿を促進し、
それによってＳｅの除去率を向上させることができる。 ２Ｆｅ2+＋１／２・Ｏ2 ＋２Ｈ+ →２Ｆｅ3+＋Ｈ2 Ｏ （８） 酸素含有気体の導入方法として、バブリング方式、スプ
レー方式等の通常の気液接触方法を採用できる。その
際、排煙脱硫排水の酸化還元状態により酸素含有気体の
導入量を調整することが望ましく、例えば排煙脱硫排水
の酸化還元電位（ＤＲＰ）を測定し、その測定値に基づ
いて空気の流入量を調整する。By feeding an oxygen-containing gas such as air into the flue gas desulfurization effluent which is in contact with iron, the following reaction equations (8) and (3), (6), (7) ) Promotes the production and precipitation of iron compounds by the reaction as shown in
Thereby, the removal rate of Se can be improved. 2Fe 2+ + 1/2 · O 2 + 2H + → 2Fe 3+ + H 2 O (8) As a method for introducing the oxygen-containing gas, a normal gas-liquid contact method such as a bubbling method or a spray method can be adopted. At that time, it is desirable to adjust the introduction amount of the oxygen-containing gas according to the redox state of the flue gas desulfurization wastewater. For example, the redox potential (DRP) of the flue gas desulfurization wastewater is measured, and the inflow of air is based on the measured value. Adjust the amount.

【００２２】その他の金属、例えばＭｎ、Ｃｕ、Ｎｉ等
の金属でも、Ｆｅと同様な反応により、酸化性物質の酸
化還元反応が進行する。例えば、Ｍｎを例に取ると、 Ｍｎ＋Ｓ2 Ｏ8 2- →Ｍｎ2+＋２ＳＯ4 2- Ｍｎ2+＋Ｓ2 Ｏ8 2- →Ｍｎ4+＋２ＳＯ4 2- Ｃｕでは、Ｃｕ+ →Ｃｕ2+→Ｃｕ3+ となって、Ｃｕ3+は不安定であるが、Ｃｕ、Ｃｕ+ 及び
Ｃｕ2+が還元剤として使用でき、 また、Ｎｉでは、Ｎｉ+ →Ｎｉ2+→Ｎｉ3+→Ｎｉ4+ となって、Ｎｉ、Ｎｉ+ 、Ｎｉ2+及びＮｉ3+が還元剤と
して使用できる。With other metals, for example, metals such as Mn, Cu, and Ni, the oxidation-reduction reaction of the oxidizing substance proceeds by the same reaction as Fe. For example, taking Mn as an example, Mn + S 2 O 8 2- → Mn 2+ + 2SO 4 2- Mn 2+ + S 2 O 8 2- → Mn 4+ + 2SO 4 2- Cu, Cu + → Cu 2+ → It becomes Cu 3+ and Cu 3+ is unstable, but Cu, Cu + and Cu 2+ can be used as a reducing agent, and in Ni, Ni + → Ni 2+ → Ni 3+ → Ni 4 Become + and Ni, Ni + , Ni 2+ and Ni 3+ can be used as reducing agents.

【００２３】実験例３ 更に、低価数の鉄化合物、即ち塩化第１鉄を使用し実験
例１と同様にして酸化性物質とＳｅの除去実験を行い、
図１に示す結果と同様な結果を得た。 Experimental Example 3 Further, an experiment for removing an oxidizing substance and Se was conducted in the same manner as in Experimental Example 1 using a low valence iron compound, ie, ferrous chloride.
Results similar to those shown in FIG. 1 were obtained.

【００２４】上記知見に基づいて、本発明に係る別の排
煙脱硫排水の処理方法（以下、第２発明方法と言う）
は、排ガス中の硫黄酸化物を除去する排煙脱硫装置から
排出される排煙脱硫排水を処理する方法であって、排煙
脱硫排水にＦｅ、Ｍｎ、Ｎｉ及びＣｕの低価数の化合物
から選ばれた少なくとも１種類の金属化合物を接触させ
るか、若しくは前記金属化合物の溶液又はスラリーを混
合して、排煙脱硫排水中の酸化性物質及びセレン（Ｓ
ｅ）を除去することを特徴としている。Based on the above findings, another flue gas desulfurization wastewater treatment method according to the present invention (hereinafter referred to as the second invention method)
Is a method for treating flue gas desulfurization effluent discharged from a flue gas desulfurization device for removing sulfur oxides in exhaust gas, wherein the flue gas desulfurization effluent is selected from compounds having low valences of Fe, Mn, Ni and Cu. At least one selected metal compound is brought into contact, or a solution or slurry of the metal compound is mixed, and an oxidizing substance and selenium (S) in flue gas desulfurization wastewater are mixed.
It is characterized in that e) is removed.

【００２５】排煙脱硫排水のｐＨは、金属の場合と同様
に、３．０以上が望ましく、更に望ましくは３．０〜１
０の範囲である。ｐＨの調整は、排煙脱硫排水が金属化
合物に接触する過程で又は金属化合物の溶液、スラリを
混合する過程で行っても良く、その過程の前で行っても
良い。Ｓｅの除去のためには、Ｓｅ濃度の２倍から１０
００倍の範囲の規定モル濃度になるように低価数の金属
化合物を排煙脱硫排水に添加する。一方、酸化性物質の
除去ためには、酸化性物質濃度の１倍から１００倍の範
囲の規定モル濃度になるように低価数の金属化合物を排
煙脱硫排水に添加する。従って、実際には、酸化性物質
及びＳｅの双方を除去できるモル濃度になるように過剰
量の低価数の金属化合物を排煙脱硫排水に添加する。The pH of the flue gas desulfurization wastewater is preferably 3.0 or more, more preferably 3.0 to 1 as in the case of metal.
It is in the range of 0. The pH may be adjusted in the process of contacting the flue gas desulfurization wastewater with the metal compound or in the process of mixing the solution of the metal compound and the slurry, or may be performed before the process. To remove Se, the concentration should be 2 to 10 times the Se concentration.
A low valence metal compound is added to the flue gas desulfurization effluent so that the specified molar concentration is in the range of 00 times. On the other hand, in order to remove the oxidizing substance, a low valence metal compound is added to the flue gas desulfurization wastewater so that the specified molar concentration is in the range of 1 to 100 times the oxidizing substance concentration. Therefore, in practice, an excessive amount of a low valence metal compound is added to the flue gas desulfurization wastewater so that the oxidizing agent and Se can be removed in a molar concentration.

【００２６】本明細書で低価数の金属化合物とは、酸化
されて価数の高い金属化合物に転化する金属化合物を言
う。鉄化合物を例にすると、塩化第２鉄（ＦｅＣｌ2 ）
は低価数の金属化合物である。また、Ｆｅ、Ｍｎ、Ｎｉ
及びＣｕの金属の低価数の化合物の例は、Ｆｅ2+、Ｍｎ
2+、Ｎｉ+ 、Ｎｉ2+、Ｎｉ3+、Ｃｕ+ 、Ｃｕ2+のそれぞ
れの酸化物、水酸化物、塩化物、硫酸塩、炭酸塩、硫酸
塩などである。In the present specification, the low valence metal compound means a metal compound which is oxidized to be converted into a high valence metal compound. Taking an iron compound as an example, ferric chloride (FeCl 2 )
Is a low valence metal compound. In addition, Fe, Mn, Ni
Examples of low valence compounds of the metals Cu and Cu include Fe 2+ , Mn
The oxides, hydroxides, chlorides, sulfates, carbonates, sulfates, etc. of 2+ , Ni + , Ni2 + , Ni3 + , Cu + , Cu2 + are included.

【００２７】本発明に係る排煙脱硫排水の処理方法（以
下、第３発明方法）は、排ガス中の硫黄酸化物を除去す
る排煙脱硫装置から排出される排煙脱硫排水を処理する
方法であって、Ｆｅ、Ｍｎ、Ｎｉ及びＣｕの金属並びに
それらの金属の低価数の化合物からなる群から選ばれた
少なくとも１種類の金属又は１種類の金属化合物を排煙
脱硫排水に接触させる工程及び前記金属化合物の溶液又
はスラリを排煙脱硫排水に混合する工程の少なくとも一
つからなる第１工程と、排煙脱硫排水のｐＨを調整し、
又は酸素含有ガスを送入して沈殿物を生成させる第２工
程とを備え、排煙脱硫排水中の酸化性物質及びセレン
（Ｓｅ）を除去することを特徴としている。The method for treating flue gas desulfurization wastewater according to the present invention (hereinafter referred to as the third invention method) is a method for treating flue gas desulfurization wastewater discharged from a flue gas desulfurization apparatus for removing sulfur oxides in exhaust gas. And a step of contacting at least one metal selected from the group consisting of Fe, Mn, Ni and Cu metals and compounds having a low valence of these metals, or one metal compound with flue gas desulfurization wastewater, Adjusting the pH of the flue gas desulfurization effluent, the first step comprising at least one step of mixing the solution or slurry of the metal compound with the flue gas desulfurization effluent;
Or a second step of feeding an oxygen-containing gas to generate a precipitate, and removing the oxidizing substance and selenium (Se) in the flue gas desulfurization wastewater.

【００２８】本発明方法では、積極的に沈殿物を生成さ
せる第２工程を設けることにより、酸化性物質に加えて
特にＳｅを高除去率にて排煙脱硫排水から除去できる。
好適な実施態様は、第２工程では排煙脱硫排水のｐＨを
４〜９の範囲に調整し、第１工程では排煙脱硫排水のｐ
Ｈを第２工程でのｐＨと同じか又はより低くすることを
特徴としている。ｐＨをこの範囲に調整することによ
り、酸化性物質及びＳｅの除去が促進されるからであ
る。In the method of the present invention, by providing the second step of positively forming a precipitate, Se can be removed from the flue gas desulfurization effluent particularly at a high removal rate in addition to the oxidizing substance.
A preferred embodiment adjusts the pH of the flue gas desulfurization wastewater in the range of 4 to 9 in the second step, and adjusts the pH of the flue gas desulfurization wastewater in the first step.
It is characterized in that H is equal to or lower than the pH in the second step. This is because adjusting the pH to this range accelerates the removal of oxidizing substances and Se.

【００２９】本発明方法の実施装置は、塩酸等の酸、又
は苛性ソーダ等のアルカリを添加してｐＨを調整する手
段と攪拌手段とを備えた反応槽と反応槽で生じた生成物
を沈殿させる沈殿槽とから構成される。反応槽内に、例
えば金属鉄を単に沈積させても良く、また金属鉄、塩化
鉄の粉粒体を添加して排煙脱硫排水中に流動層を形成し
ても良い。また、金属及び金属化合物の充填層を備えた
固定床式の反応槽でも良い。The apparatus for carrying out the method of the present invention comprises a reaction tank equipped with a means for adjusting the pH by adding an acid such as hydrochloric acid or an alkali such as caustic soda, and a product produced in the reaction tank. It consists of a settling tank. For example, metallic iron may be simply deposited in the reaction tank, or powdered particles of metallic iron or iron chloride may be added to form a fluidized bed in the flue gas desulfurization wastewater. Further, a fixed bed type reaction tank provided with a packed bed of metal and metal compound may be used.

【発明の実施の形態】BEST MODE FOR CARRYING OUT THE INVENTION

【００３０】以下に、添付図面を参照し、実施例を挙げ
て本発明の実施の形態を具体的かつ詳細に説明する。本
発明方法を実施する装置１０は、排煙脱硫排水（以下、
簡単に排水と言う）を導入して金属又は金属化合物と反
応させる反応槽１２と、ｐＨ調整槽１４と、沈殿槽１６
とから構成されている。反応槽１２は、酸、例えば塩
酸、又はアルカリ、例えばＮａＯＨを添加して排水のｐ
Ｈを３〜９に調整する手段１８と、金属鉄、又はＦｅＣ
ｌ2 、ＦｅＣｌ3等の鉄化合物の粉粒体を添加する手段
２０と、攪拌機２２と、槽に滞留する排水を５０°C か
ら８０°C の範囲の温度に加熱するスチームコイル２４
とを備えている。ｐＨ調整槽１４は、アルカリ、例えば
ＮａＯＨ、又は酸、例えば塩酸添加して排水のｐＨを３
〜７に調整する手段２６と攪拌機２８とを備えて、鉄の
水酸化物を生成する。また、酸化用空気を送入する空気
ノズル３０を設けて、鉄の酸化物を生成するようにして
も良い。沈殿槽１６は、常用の沈降分離型の沈殿槽で、
沈殿物を含む濃縮液と、処理水とに分離する。Hereinafter, embodiments of the present invention will be described specifically and in detail with reference to the accompanying drawings. The apparatus 10 for carrying out the method of the present invention is a flue gas desulfurization wastewater (hereinafter,
A reaction tank 12 for introducing waste water) to react with a metal or a metal compound, a pH adjusting tank 14, and a precipitation tank 16
It is composed of The reaction tank 12 is added with an acid, for example, hydrochloric acid, or an alkali, for example, NaOH, to remove waste water.
Means 18 for adjusting H to 3 to 9 and metallic iron or FeC
a means 20 for adding the powdery grains of l 2, FeCl 3, etc. iron compounds, steam coils 24 to heat the agitator 22, the waste water accumulated in the tank to a temperature in the range at 80 ° C for from 50 ° C
And The pH adjusting tank 14 adds alkali such as NaOH or acid such as hydrochloric acid to adjust the pH of the waste water to 3
A means 26 for adjusting to ˜7 and a stirrer 28 are provided to produce iron hydroxide. Further, an air nozzle 30 for feeding the oxidizing air may be provided to generate iron oxide. The settling tank 16 is a conventional settling separation type settling tank,
The concentrate containing the precipitate and the treated water are separated.

【００３１】反応槽１２では、添加された金属鉄等の粉
粒体を排水中で攪拌機２２で攪拌することにより、流動
層を形成することができる。攪拌機２２の攪拌により金
属鉄等の粉粒体の流動層を形成する代わりに、排水を噴
流状で反応槽１２内に送入し、排水の流体攪拌を利用し
て金属鉄等の粉粒体の流動層を形成することもできる。
また、反応槽１２として、既知の横型固定床式反応槽又
は縦型固定床式反応槽を使用することもできる。固定床
式反応槽では、還元剤として金属鉄を充填した固定床
（充填層）を備え、そこに排煙脱硫排水を通水する。金
属鉄として、大きな粒状又は塊状の鉄材を使用できる。
また、開放槽内の排水に金属鉄を沈積させただけのもの
でも良い。金属鉄に代えて鉄化合物を充填しても良い。
また、水素ガスが発生する場合には、開放型槽を使用す
るか、また固定床の下部から不活性ガスを送入して水素
ガスを同伴して排出させても良い。In the reaction tank 12, the fluidized bed can be formed by stirring the added powdered material such as metallic iron in the waste water with the stirrer 22. Instead of forming a fluidized bed of powdered metal such as metallic iron by the agitator 22, the wastewater is sent in the form of a jet into the reaction tank 12, and the powdered granular material such as metal iron is used by stirring the fluid of the wastewater. It is also possible to form a fluidized bed.
Further, as the reaction tank 12, a known horizontal fixed bed reaction tank or vertical fixed bed reaction tank can be used. The fixed bed reactor has a fixed bed (packed bed) filled with metallic iron as a reducing agent, through which flue gas desulfurization wastewater is passed. As the metallic iron, a large granular or massive iron material can be used.
Further, it may be one in which metallic iron is simply deposited in the drainage in the open tank. An iron compound may be filled instead of metallic iron.
When hydrogen gas is generated, an open tank may be used, or an inert gas may be fed in from the lower part of the fixed bed and hydrogen gas may be accompanied and discharged.

【００３２】本実施例では、上述した装置１０を使用し
て、先ず、排水を反応槽１２に導入して、ｐＨを３〜４
に調整しつつ粉体状の塩化第１鉄を約５０PPM （鉄重量
ppm）に成るように排水に添加する。これにより、塩化
第１鉄は排水中の酸化性物質を還元して、例えば硫黄過
酸化物を硫酸イオンに転化する。必要に応じて、スチー
ムコイル２４により排水を加熱し、鉄金属又は塩化第１
鉄の酸化還元反応を促進する。In this embodiment, using the apparatus 10 described above, first, waste water is introduced into the reaction tank 12 to adjust the pH to 3-4.
Adjust the powdered ferrous chloride to about 50 PPM (weight of iron
ppm) to be added to the wastewater. As a result, ferrous chloride reduces the oxidizing substances in the waste water and converts, for example, sulfur peroxide into sulfate ions. If necessary, the waste water is heated by the steam coil 24, and ferrous metal or chloride first
Promotes the redox reaction of iron.

【００３３】次いで、ｐＨ調整槽１４で８付近にｐＨを
調整して鉄水酸化物を生成し、次いで沈殿槽１６に導入
する。沈殿槽１６では、鉄水酸化物を沈殿させる。Ｓｅ
は鉄水酸化物に随伴して、例えば共沈状態で排水から分
離して沈殿する。これにより、Ｓｅを含む沈殿物を含有
する濃縮液と沈殿物の濃度が濃縮液より小さい処理排水
とに分離する。ｐＨ調整槽１４で鉄水酸化物に代えて、
空気により金属イオンを酸化した鉄酸化物を生成し、そ
れを沈殿槽１６で沈殿させても良い。処理排水及び濃縮
液はそれぞれライン３２、３４を経由して系外に送出さ
れる。Next, the pH is adjusted to around 8 in the pH adjusting tank 14 to produce iron hydroxide, which is then introduced into the precipitation tank 16. In the settling tank 16, iron hydroxide is settled. Se
Is associated with iron hydroxide and is separated from the wastewater and precipitated, for example, in a coprecipitation state. As a result, the concentrate containing the precipitate containing Se and the treated wastewater having a concentration of the precipitate smaller than that of the concentrate are separated. Instead of iron hydroxide in the pH adjusting tank 14,
Iron oxide may be generated by oxidizing metal ions with air, and the iron oxide may be precipitated in the precipitation tank 16. The treated wastewater and the concentrated liquid are sent out of the system via lines 32 and 34, respectively.

【００３４】[0034]

【実施例】実施例１ 上述した反応槽１２と同様な実験用反応槽を構成し、以
下の条件で、排煙脱硫排水を原水として通水し、第１発
明方法を実施し、その評価を行った。 １．原水 ：酸化性物質及びＳｅを含む排煙脱硫排水 酸化性物質の濃度 ：１１mg−cl/L−原水（塩素換算値） Ｓｅの濃度 ：０．６mg/L−原水 通水量 ：０．４L/Hr 温度 ：５０°C ２．本発明方法の実施条件 反応槽の容量 ：２７０ｃc 金属 ：鉄粒、６０ｃc の流動床 温度 ：５５°C ｐＨ ：４．５ Example 1 An experimental reaction tank similar to the above-mentioned reaction tank 12 was constructed, and the flue gas desulfurization waste water was passed as raw water under the following conditions, and the first invention method was carried out, and its evaluation was performed. went. 1. Raw water: Flue gas desulfurization wastewater containing oxidizing substances and Se Concentration of oxidizing substances: 11 mg-cl / L- Raw water (chlorine conversion value) Se concentration: 0.6 mg / L- Raw water Water flow rate: 0.4 L / Hr Temperature: 50 ° C 2. Conditions for carrying out the method of the present invention Volume of reactor: 270 cc Metal: Iron particles, fluid bed of 60 cc Temperature: 55 ° C pH: 4.5

【００３５】処理した原水をミリポアフィルタによる吸
引濾過により沈殿物を除去して試料処理水を得た後、分
析したところ、酸化性物質の濃度は０．１mg−cl/L−処
理水（塩素換算値）以下、Ｓｅの濃度は、０．３１mg/L
−処理水であった。実施例１の結果から判るように、第
１発明方法は、原水中の酸化性物質の９９％以上及びＳ
ｅの４８％を一つの工程で同時に除去できることを示し
ている。また、処理水の酸化性物質濃度及びＳｅ濃度は
極く低濃度にまで処理されている。The treated raw water was subjected to suction filtration with a Millipore filter to remove precipitates to obtain sample treated water, which was then analyzed to find that the concentration of oxidizing substances was 0.1 mg-cl / L-treated water (chlorine conversion). Value) or less, Se concentration is 0.31 mg / L
-Was treated water. As can be seen from the results of Example 1, the method of the first invention is 99% or more of the oxidizing substances in the raw water and S.
It shows that 48% of e can be removed simultaneously in one step. Further, the oxidant concentration and the Se concentration of the treated water are treated to be extremely low.

【００３６】実施例２ 実施例１と同じ構成の実験装置を使用して、以下の条件
で、実施例１と同じ排煙脱硫排水を原水として通水し、
第２発明方法を実施し、その評価を行った。 １．原水 ：実施例１と同じ ２．本発明方法の実施条件 反応槽の容量 ：２７０ｃc 金属化合物 ：ＦｅＣｌ2 を７０mg−Fe/L−原水の添加率で添加 温度 ：５０°C ｐＨ ：４．５ 処理した原水をミリポアフィルタによる吸引濾過により
沈殿物を除去して試料処理水を得た後、分析したとこ
ろ、酸化性物質の濃度は０．１mg−cl/L−処理水（塩素
換算値）以下、Ｓｅの濃度は、０．３mg/L−処理水であ
った。 Example 2 The same flue gas desulfurization wastewater as in Example 1 was passed as raw water under the following conditions using the experimental apparatus having the same configuration as in Example 1,
The second invention method was carried out and evaluated. 1. Raw water: same as in Example 1. Conditions for carrying out the method of the present invention Volume of reaction tank: 270 cc Metal compound: FeCl 2 was added at an addition rate of 70 mg-Fe / L-raw water Temperature: 50 ° C pH: 4.5 Treated raw water was filtered by suction with a Millipore filter After the precipitate was removed to obtain sample treated water, the sample was analyzed and found that the concentration of oxidizing substances was 0.1 mg-cl / L-treated water (chlorine conversion value) or less, and the concentration of Se was 0.3 mg / It was L-treated water.

【００３７】実施例２の結果から判るように、第２発明
方法は、原水中の酸化性物質の９９％以上及びＳｅの５
１％を一つの工程で同時に除去できることを示してい
る。As can be seen from the results of Example 2, the second method of the present invention uses 99% or more of the oxidizing substances in the raw water and 5% of Se.
It shows that 1% can be removed simultaneously in one step.

【００３８】実施例３ 上述した反応槽１２及びｐＨ調整槽１４と同様な実験装
置を構成し、以下の条件で、酸化性物質及びＳｅを含む
排煙脱硫排水を原水として通水し、種々のｐＨの下で第
３発明方法を実施し、その評価を行った。 １．原水 ：実施例１と同じ ２．第１工程の実施条件 反応槽の容量 ：２７０ｃc 金属 ：鉄粒、６０ｃc の流動床 温度 ：５５°C ｐＨ ：表２に示す通り ３．第２工程の実施条件 ｐＨ調整槽の容量 ：２４０ ｐＨ ：表２に示す通り ４．酸化性物質及びＳｅの除去率：表２に示す通り Example 3 An experimental apparatus similar to the above-mentioned reaction tank 12 and pH adjusting tank 14 was constructed, and flue gas desulfurization wastewater containing an oxidizing substance and Se was passed as raw water under the following conditions to obtain various water. The third invention method was carried out under pH and evaluated. 1. Raw water: same as in Example 1. Conditions for carrying out the first step Capacity of reaction tank: 270 cc Metal: Iron particles, fluid bed of 60 cc Temperature: 55 ° C pH: As shown in Table 2. 2. Implementation conditions of the second step Volume of pH adjusting tank: 240 pH: As shown in Table 2. Removal rate of oxidizing substances and Se: As shown in Table 2.

【表２】 [Table 2]

【００３９】実施例３の結果から判るように、第３発明
方法は、原水中の酸化性物質の約１００％及びＳｅの６
０％以上を一つのプロセスで同時に除去できることを示
している。また、処理水の酸化性物質及びＳｅは、十分
に除去され、低濃度になっている。As can be seen from the results of Example 3, the method of the third aspect of the present invention uses about 100% of the oxidizing substances in the raw water and 6% of Se.
It shows that 0% or more can be removed simultaneously by one process. In addition, the oxidizing substances and Se in the treated water are sufficiently removed to have a low concentration.

【００４０】[0040]

【発明の効果】第１発明方法によれば、特定した金属と
排煙脱硫排水とを接触させることにより、酸化性物質と
Ｓｅとを同時に除去することができる。また、第２発明
方法によれば、排煙脱硫排水に金属化合物を接触させ、
若しくはその溶液又はスラリを混合することにより、酸
化性物質とＳｅとを同時に除去できる。更に、第３発明
方法によれば、金属又は金属の低価数の化合物を排煙脱
硫排水に接触させる工程及び金属化合物の溶液又はスラ
リを排煙脱硫排水に混合する工程の少なくとも一つから
なる第１工程に加えて、排煙脱硫排水のｐＨを調整し、
又は酸素含有ガスを送入して、積極的に沈殿物を生成さ
せる第２工程を備えることにより、酸化性物質及びＳｅ
を更に高除去率で除去することができる。これにより、
一つのプロセスで酸化性物質とＳｅとを効率良く同時に
除去し、かつ排水処理装置に送水される排煙脱硫排水中
の金属イオンの量を低減させている。According to the method of the first invention, the oxidizing substance and Se can be simultaneously removed by bringing the specified metal into contact with the flue gas desulfurization wastewater. Further, according to the second invention method, the flue gas desulfurization wastewater is contacted with a metal compound,
Alternatively, the oxidizing substance and Se can be simultaneously removed by mixing the solution or the slurry. Furthermore, according to the method of the third aspect of the invention, it comprises at least one of a step of bringing a metal or a compound having a low valence of metal into contact with the flue gas desulfurization wastewater, and a step of mixing a solution or slurry of a metal compound with the flue gas desulfurization wastewater. In addition to the first step, adjust the pH of flue gas desulfurization wastewater,
Alternatively, by providing a second step of feeding in an oxygen-containing gas to positively generate a precipitate, the oxidizing substance and Se
Can be removed at a higher removal rate. This allows
In one process, oxidizing substances and Se are efficiently removed at the same time, and the amount of metal ions in the flue gas desulfurization wastewater sent to the wastewater treatment equipment is reduced.

【図面の簡単な説明】[Brief description of drawings]

【図１】還元剤として金属鉄を使用した実験例１で得た
空塔速度と酸化性物質除去率との関係を示すグラフであ
る。FIG. 1 is a graph showing the relationship between superficial velocity and oxidizing substance removal rate obtained in Experimental Example 1 using metallic iron as a reducing agent.

【図２】本発明方法を実施する装置の概略フローシート
である。FIG. 2 is a schematic flow sheet of an apparatus for carrying out the method of the present invention.

【図３】従来の石膏分離装置のフローシートである。FIG. 3 is a flow sheet of a conventional gypsum separating device.

【符号の説明】[Explanation of symbols]

１ 石膏分離装置 ２ 反応槽 ４ 排出ポンプ ６ 固液分離装置又は石膏脱水機 ８ 排水処理装置 １０ 本発明方法を実施する装置 １２ 反応槽 １４ ｐＨ調整槽 １６ 沈殿槽 １８ ｐＨ調整手段 ２０ 金属添加手段 ２２ 攪拌機 ２４ スチームコイル ２６ ｐＨ調整手段 ２８ 攪拌機 ３０ 空気ノズル ３２、３４ ライン DESCRIPTION OF SYMBOLS 1 Gypsum separation device 2 Reaction tank 4 Discharge pump 6 Solid-liquid separation device or gypsum dewatering machine 8 Waste water treatment device 10 Device for carrying out the method of the present invention 12 Reaction tank 14 pH adjustment tank 16 Precipitation tank 18 pH adjustment means 20 Metal addition means 22 Stirrer 24 Steam coil 26 pH adjusting means 28 Stirrer 30 Air nozzle 32, 34 line

Claims (8)

【特許請求の範囲】[Claims] 【請求項１】 排ガス中の硫黄酸化物を除去する排煙脱
硫装置から排出される排煙脱硫排水を処理する方法であ
って、 Ｆｅ、Ｍｎ、Ｎｉ及びＣｕから選ばれた少なくとも１種
類の金属を排煙脱硫排水に接触させ、排煙脱硫排水中の
酸化性物質及びセレン（Ｓｅ）を除去することを特徴と
する排煙脱硫排水の処理方法。1. A method for treating flue gas desulfurization wastewater discharged from a flue gas desulfurization apparatus for removing sulfur oxides in exhaust gas, comprising at least one metal selected from Fe, Mn, Ni and Cu. A method for treating flue gas desulfurization wastewater, which comprises contacting flue gas desulfurization wastewater to remove oxidizing substances and selenium (Se) in the flue gas desulfurization wastewater. 【請求項２】 排煙脱硫排水のｐＨを３．０以上に調整
することを特徴とする請求項１に記載の排煙脱硫排水の
処理方法。2. The method for treating flue gas desulfurization wastewater according to claim 1, wherein the pH of the flue gas desulfurization wastewater is adjusted to 3.0 or higher. 【請求項３】 前記金属と接触している排煙脱硫排水中
に酸素含有気体を送入することを特徴とする請求項１又
は２に記載の排煙脱硫排水の処理方法。3. The method for treating flue gas desulfurization wastewater according to claim 1, wherein an oxygen-containing gas is fed into the flue gas desulfurization wastewater which is in contact with the metal. 【請求項４】 排ガス中の硫黄酸化物を除去する排煙脱
硫装置から排出される排煙脱硫排水を処理する方法であ
って、 排煙脱硫排水にＦｅ、Ｍｎ、Ｎｉ及びＣｕの低価数の化
合物から選ばれた少なくとも１種類の金属化合物を接触
させるか、若しくは前記金属化合物の溶液又はスラリー
を混合して、排煙脱硫排水中の酸化性物質及びセレン
（Ｓｅ）を除去することを特徴とする排煙脱硫排水の処
理方法。4. A method for treating flue gas desulfurization wastewater discharged from a flue gas desulfurization apparatus for removing sulfur oxides in exhaust gas, wherein the flue gas desulfurization wastewater has a low valence of Fe, Mn, Ni and Cu. Of at least one metal compound selected from the compounds described above or mixed with a solution or slurry of the metal compound to remove oxidizing substances and selenium (Se) in the flue gas desulfurization wastewater. Flue gas desulfurization wastewater treatment method. 【請求項５】 排煙脱硫排水のｐＨを３．０以上に調整
することを特徴とする請求項４に記載の排煙脱硫排水の
処理方法。5. The method for treating flue gas desulfurization wastewater according to claim 4, wherein the pH of the flue gas desulfurization wastewater is adjusted to 3.0 or higher. 【請求項６】 前記金属化合物と接触している排煙脱硫
排水、若しくは前記金属化合物の溶液又はスラリが混合
された排煙脱硫排水に酸素含有気体を送入することを特
徴とする請求項５に記載の排煙脱硫排水の処理方法。6. An oxygen-containing gas is fed into the flue gas desulfurization wastewater in contact with the metal compound or the flue gas desulfurization wastewater mixed with a solution or slurry of the metal compound. The method for treating flue gas desulfurization wastewater described in. 【請求項７】 排ガス中の硫黄酸化物を除去する排煙脱
硫装置から排出される排煙脱硫排水を処理する方法であ
って、 Ｆｅ、Ｍｎ、Ｎｉ及びＣｕの金属並びにそれらの金属の
低価数の化合物からなる群から選ばれた少なくとも１種
類の金属又は１種類の金属化合物を排煙脱硫排水に接触
させる工程及び前記金属化合物の溶液又はスラリを排煙
脱硫排水に混合する工程の少なくとも一つからなる第１
工程と、 排煙脱硫排水のｐＨを調整し、又は酸素含有ガスを送入
して沈殿物を生成させる第２工程とを備え、 排煙脱硫排水中の酸化性物質及びセレン（Ｓｅ）を除去
することを特徴とする排煙脱硫排水の処理方法。7. A method for treating flue gas desulfurization effluent discharged from a flue gas desulfurization apparatus for removing sulfur oxides in exhaust gas, comprising metals of Fe, Mn, Ni and Cu and low prices of these metals. At least one of the step of contacting at least one metal selected from the group consisting of several compounds or one metal compound with the flue gas desulfurization wastewater, and the step of mixing the solution or slurry of the metal compound with the flue gas desulfurization wastewater. First consisting of two
A oxidant substance and selenium (Se) in the flue gas desulfurization wastewater are removed by providing a step and a second step of adjusting the pH of the flue gas desulfurization wastewater or feeding an oxygen-containing gas to generate a precipitate. A method for treating flue gas desulfurization wastewater, which comprises: 【請求項８】 第２工程では排煙脱硫排水のｐＨを４〜
９の範囲に調整し、第１工程では排煙脱硫排水のｐＨを
第２工程でのｐＨと同じか又はより低くすることを特徴
とする請求項７に記載の排煙脱硫排水の処理方法。8. In the second step, the pH of the flue gas desulfurization wastewater is adjusted to 4 to 4.
9. The method for treating flue gas desulfurization wastewater according to claim 7, wherein the pH of the flue gas desulfurization wastewater is adjusted to the range of 9 and the pH of the flue gas desulfurization wastewater is made equal to or lower than the pH in the second step in the first step.
JP21976595A 1995-08-04 1995-08-04 Treatment of flue gas desulfurization wastewater Expired - Lifetime JP3385137B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP21976595A JP3385137B2 (en) 1995-08-04 1995-08-04 Treatment of flue gas desulfurization wastewater

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP21976595A JP3385137B2 (en) 1995-08-04 1995-08-04 Treatment of flue gas desulfurization wastewater

Publications (2)

Publication Number Publication Date
JPH0947790A true JPH0947790A (en) 1997-02-18
JP3385137B2 JP3385137B2 (en) 2003-03-10

Family

ID=16740657

Family Applications (1)

Application Number Title Priority Date Filing Date
JP21976595A Expired - Lifetime JP3385137B2 (en) 1995-08-04 1995-08-04 Treatment of flue gas desulfurization wastewater

Country Status (1)

Country Link
JP (1) JP3385137B2 (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001025777A (en) * 1999-07-15 2001-01-30 Kurita Water Ind Ltd Water treating method
JP2002126757A (en) * 2000-10-30 2002-05-08 Chiyoda Corp Method for treatment of waste water containing selenium
JP2002126758A (en) * 2000-10-30 2002-05-08 Taiheiyo Cement Corp Method for treating water
JP2006116469A (en) * 2004-10-22 2006-05-11 Dowa Mining Co Ltd Treatment method for selenium-containing water
JP2006334492A (en) * 2005-06-01 2006-12-14 Dowa Holdings Co Ltd Method for treating selenium-containing water
JP2008540092A (en) * 2005-05-12 2008-11-20 マイクロドロップ・アクア・エイピーエス Method and apparatus for removing trace species, especially arsenic, from water
JP2009160568A (en) * 2007-09-11 2009-07-23 Central Res Inst Of Electric Power Ind Treating method of selenium-containing liquid
JP2011072940A (en) * 2009-09-30 2011-04-14 Chiyoda Kako Kensetsu Kk Treatment method of reducing selenium-containing waste water
JP2015128746A (en) * 2014-01-07 2015-07-16 オルガノ株式会社 Apparatus and method for treating selenium-containing water
KR20160003033A (en) 2013-06-28 2016-01-08 미츠비시 쥬고우 메카토로시스테무즈 가부시키가이샤 Method for removing selenium and apparatus for removing selenium
JP2019077567A (en) * 2017-10-19 2019-05-23 一般財団法人電力中央研究所 Method for separating selenium and tellurium dissolved in molten chloride

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001025777A (en) * 1999-07-15 2001-01-30 Kurita Water Ind Ltd Water treating method
JP4507267B2 (en) * 1999-07-15 2010-07-21 栗田工業株式会社 Water treatment method
JP4597346B2 (en) * 2000-10-30 2010-12-15 千代田化工建設株式会社 Treatment of selenium-containing wastewater
JP2002126757A (en) * 2000-10-30 2002-05-08 Chiyoda Corp Method for treatment of waste water containing selenium
JP2002126758A (en) * 2000-10-30 2002-05-08 Taiheiyo Cement Corp Method for treating water
JP2006116469A (en) * 2004-10-22 2006-05-11 Dowa Mining Co Ltd Treatment method for selenium-containing water
JP2008540092A (en) * 2005-05-12 2008-11-20 マイクロドロップ・アクア・エイピーエス Method and apparatus for removing trace species, especially arsenic, from water
JP2006334492A (en) * 2005-06-01 2006-12-14 Dowa Holdings Co Ltd Method for treating selenium-containing water
JP2009160568A (en) * 2007-09-11 2009-07-23 Central Res Inst Of Electric Power Ind Treating method of selenium-containing liquid
JP2011072940A (en) * 2009-09-30 2011-04-14 Chiyoda Kako Kensetsu Kk Treatment method of reducing selenium-containing waste water
KR20160003033A (en) 2013-06-28 2016-01-08 미츠비시 쥬고우 메카토로시스테무즈 가부시키가이샤 Method for removing selenium and apparatus for removing selenium
US10919790B2 (en) 2013-06-28 2021-02-16 Mitsubishi Power Environmental Solutions, Ltd. Method for removing selenium and apparatus for removing selenium
JP2015128746A (en) * 2014-01-07 2015-07-16 オルガノ株式会社 Apparatus and method for treating selenium-containing water
JP2019077567A (en) * 2017-10-19 2019-05-23 一般財団法人電力中央研究所 Method for separating selenium and tellurium dissolved in molten chloride

Also Published As

Publication number Publication date
JP3385137B2 (en) 2003-03-10

Similar Documents

Publication Publication Date Title
JP5417927B2 (en) Coal gasification wastewater treatment method
JPS5919757B2 (en) Wastewater treatment method
JP3385137B2 (en) Treatment of flue gas desulfurization wastewater
JP3573950B2 (en) Exhaust gas desulfurization method
KR0174794B1 (en) Exhaust gas desulfurization process
SK280506B6 (en) Anaerobic removal of sulphur compounds from wastewater
US5366710A (en) Process for removing nitrogen oxides and sulfur oxides from gaseous stream
US20240207785A1 (en) Process to continuously treat a hydrogen sulphide comprising gas
JP3572233B2 (en) Flue gas desulfurization method and flue gas desulfurization system
CN108137359B (en) Method for purifying hazardous substance-containing liquid and hazardous substance-containing liquid purification apparatus for carrying out the method
JP3577832B2 (en) Method for removing Se from Se-containing liquid
JP4014679B2 (en) Wastewater treatment method
JP4666275B2 (en) Treatment method for wastewater containing sulfite ions
JPH08192192A (en) Method for treating flue gas desulfurization drain
JP3504427B2 (en) Exhaust gas desulfurization method
JP6213044B2 (en) Method and apparatus for treating selenium-containing water
JP4177521B2 (en) Method for treating wastewater containing metal and ammonia
GB2163141A (en) Method for removing and recovering sulphur in elemental form from gases containing sulphur dioxide or sulphur dioxide and hydrogen sulphide
JP4597346B2 (en) Treatment of selenium-containing wastewater
JPH091160A (en) Removing method of oxidizing substance and wet type flue gas desulfurization equipment
JPH0947791A (en) Treatment of waste stack gas desulfurization effluent
JPS62225294A (en) Biological denitrification device
JP3902861B2 (en) Exhaust gas desulfurization method
JP3532028B2 (en) Exhaust gas desulfurization method
JPH07265870A (en) Treatment of dithionate ion-containing water

Legal Events

Date Code Title Description
R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20081227

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20081227

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20091227

Year of fee payment: 7

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20101227

Year of fee payment: 8

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111227

Year of fee payment: 9

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20121227

Year of fee payment: 10

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20131227

Year of fee payment: 11

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

EXPY Cancellation because of completion of term