JPH10277565A - Method for treating waste liquid - Google Patents
Method for treating waste liquidInfo
- Publication number
- JPH10277565A JPH10277565A JP8545797A JP8545797A JPH10277565A JP H10277565 A JPH10277565 A JP H10277565A JP 8545797 A JP8545797 A JP 8545797A JP 8545797 A JP8545797 A JP 8545797A JP H10277565 A JPH10277565 A JP H10277565A
- Authority
- JP
- Japan
- Prior art keywords
- waste liquid
- liquid
- dump
- chromium
- treatment
- 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- Withdrawn
Links
- 239000007788 liquid Substances 0.000 title claims abstract description 65
- 239000002699 waste material Substances 0.000 title claims abstract description 48
- 238000000034 method Methods 0.000 title claims abstract description 24
- 238000011282 treatment Methods 0.000 claims abstract description 45
- 239000002351 wastewater Substances 0.000 claims abstract description 31
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims abstract description 29
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 25
- 239000011651 chromium Substances 0.000 claims abstract description 25
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 22
- 239000010959 steel Substances 0.000 claims abstract description 22
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 14
- 239000003513 alkali Substances 0.000 claims abstract description 13
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 claims abstract description 10
- 150000004679 hydroxides Chemical class 0.000 claims abstract 3
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 claims description 14
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 claims description 14
- 238000007747 plating Methods 0.000 claims description 12
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 claims description 9
- 230000002378 acidificating effect Effects 0.000 claims description 8
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 7
- 229910000000 metal hydroxide Inorganic materials 0.000 claims description 6
- 150000004692 metal hydroxides Chemical class 0.000 claims description 6
- 230000001590 oxidative effect Effects 0.000 claims description 6
- 229910001385 heavy metal Inorganic materials 0.000 claims description 5
- 238000005406 washing Methods 0.000 claims description 4
- 230000001112 coagulating effect Effects 0.000 claims description 3
- 150000002739 metals Chemical class 0.000 claims description 2
- 230000003472 neutralizing effect Effects 0.000 claims description 2
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 abstract description 12
- 230000003647 oxidation Effects 0.000 abstract description 11
- 238000007254 oxidation reaction Methods 0.000 abstract description 11
- 229960002089 ferrous chloride Drugs 0.000 abstract description 7
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 abstract description 7
- 239000002253 acid Substances 0.000 abstract description 3
- 239000002244 precipitate Substances 0.000 abstract description 3
- 238000011284 combination treatment Methods 0.000 abstract 2
- 239000000243 solution Substances 0.000 description 33
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 26
- 238000006722 reduction reaction Methods 0.000 description 15
- 229910052742 iron Inorganic materials 0.000 description 13
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 12
- 238000004065 wastewater treatment Methods 0.000 description 8
- 238000006386 neutralization reaction Methods 0.000 description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 6
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 6
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 6
- 239000000920 calcium hydroxide Substances 0.000 description 6
- 235000011116 calcium hydroxide Nutrition 0.000 description 6
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 6
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 6
- 229910052725 zinc Inorganic materials 0.000 description 6
- 239000011701 zinc Substances 0.000 description 6
- 238000005345 coagulation Methods 0.000 description 5
- 230000015271 coagulation Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 5
- 239000000047 product Substances 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 239000003638 chemical reducing agent Substances 0.000 description 4
- 239000007800 oxidant agent Substances 0.000 description 4
- 235000011121 sodium hydroxide Nutrition 0.000 description 4
- 229910001335 Galvanized steel Inorganic materials 0.000 description 3
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 239000008397 galvanized steel Substances 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 description 3
- 238000004381 surface treatment Methods 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 229910001430 chromium ion Inorganic materials 0.000 description 2
- VQWFNAGFNGABOH-UHFFFAOYSA-K chromium(iii) hydroxide Chemical compound [OH-].[OH-].[OH-].[Cr+3] VQWFNAGFNGABOH-UHFFFAOYSA-K 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000013329 compounding Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 230000036632 reaction speed Effects 0.000 description 2
- 238000004062 sedimentation Methods 0.000 description 2
- 239000010802 sludge Substances 0.000 description 2
- KIEOKOFEPABQKJ-UHFFFAOYSA-N sodium dichromate Chemical compound [Na+].[Na+].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O KIEOKOFEPABQKJ-UHFFFAOYSA-N 0.000 description 2
- 229940079827 sodium hydrogen sulfite Drugs 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 description 1
- 241001465754 Metazoa Species 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 229910000423 chromium oxide Inorganic materials 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001784 detoxification Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- -1 etc. Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 235000014413 iron hydroxide Nutrition 0.000 description 1
- 229910000358 iron sulfate Inorganic materials 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- SURQXAFEQWPFPV-UHFFFAOYSA-L iron(2+) sulfate heptahydrate Chemical compound O.O.O.O.O.O.O.[Fe+2].[O-]S([O-])(=O)=O SURQXAFEQWPFPV-UHFFFAOYSA-L 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- NCNCGGDMXMBVIA-UHFFFAOYSA-L iron(ii) hydroxide Chemical compound [OH-].[OH-].[Fe+2] NCNCGGDMXMBVIA-UHFFFAOYSA-L 0.000 description 1
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000033116 oxidation-reduction process Effects 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 239000005028 tinplate Substances 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
Landscapes
- Separation Of Suspended Particles By Flocculating Agents (AREA)
- Removal Of Specific Substances (AREA)
- Treatment Of Water By Oxidation Or Reduction (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、鋼板等の酸洗廃
液、メッキ廃液等の重金属含有酸性廃液を無害化処理す
る方法に関し、特にクロム酸含有廃液の還元処理と第１
鉄含有廃液の酸化処理とを同時に行う、中和凝集沈殿処
理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 detoxifying an acidic waste liquid containing heavy metals such as a pickling waste liquid such as a steel plate and a plating waste liquid, and more particularly to a method for reducing a chromic acid-containing waste liquid and a first method.
The present invention relates to a neutralization coagulation sedimentation method for simultaneously performing an oxidation treatment of an iron-containing waste liquid.
【０００２】[0002]
【従来の技術】クロムメッキ処理工程やクロメート処理
工程からのクロム酸廃液等、６価クロムを含有する排水
は公害対策上、還元剤を用い３価クロムに還元した後、
中和・凝集沈殿装置を用いてクロムを分離し、排水を無
害化処理している。６価クロム化合物、一般的にクロム
酸及びその塩類は動物に対して毒性を示すので、その排
出は厳しく規制されている。金属製品工場ではクロム酸
と硫酸を含む溶液を用いてクロムメッキやクロメート処
理を行うので製品を洗浄した排水中にはクロム酸イオン
として数百〜数千ｍｇ／ｌ含まれている。また、処理に
使用する浴槽からの廃液は濃厚なクロム酸を含有するこ
とから、その処理には細心の技術と処理設備が必要であ
る。2. Description of the Related Art Wastewater containing hexavalent chromium, such as chromic acid waste liquid from a chromium plating process or a chromate treatment process, is reduced to trivalent chromium using a reducing agent for pollution control.
The chromium is separated using a neutralization / coagulation sedimentation device, and the effluent is detoxified. Since hexavalent chromium compounds, generally chromic acid and its salts, are toxic to animals, their emission is strictly regulated. In a metal product factory, chromium plating and chromate treatment are performed using a solution containing chromic acid and sulfuric acid. Therefore, the wastewater from which the product has been washed contains several hundred to several thousand mg / l as chromate ions. Further, since the waste liquid from the bathtub used for the treatment contains concentrated chromic acid, the treatment requires a meticulous technique and treatment equipment.
【０００３】クロム酸は酸性においてもアルカリ性にお
いても安定なイオンとして存在するので、他の金属と異
なり水酸化沈殿などで簡単に除去できない。クロム酸は
酸性域では強力な酸化剤であることから、溶液中に酸化
される物質があれば６価クロムは容易に還元され３価ク
ロムイオンとなる。３価クロムイオンになれば、他の金
属イオンと同様の挙動を示し、アルカリ剤の添加により
水酸化クロムとして沈殿する。また、クロム酸の還元剤
として硫酸鉄７水塩、亜硫酸水素ナトリウム、塩化第１
鉄、等が知られている。一般的に、６価クロム排水中に
亜硫酸水素ナトリウムを添加・還元し、苛性ソーダや消
石灰で水酸化クロムとして沈殿分離する方法が行われて
いる。[0003] Since chromic acid exists as a stable ion in both acidic and alkaline conditions, it cannot be easily removed by hydroxide precipitation or the like, unlike other metals. Since chromic acid is a strong oxidizing agent in an acidic region, hexavalent chromium is easily reduced to trivalent chromium ions if there is a substance oxidized in the solution. When it becomes trivalent chromium ions, it exhibits the same behavior as other metal ions, and precipitates as chromium hydroxide by the addition of an alkali agent. Further, as a reducing agent for chromic acid, iron sulfate heptahydrate, sodium hydrogen sulfite,
Iron, etc. are known. In general, sodium bisulfite is added and reduced to hexavalent chromium wastewater, and precipitated and separated as chromium hydroxide using caustic soda or slaked lime.
【０００４】一方、近年ブリキ（スズメッキ鋼板）に代
わる溶接用缶素材として、薄クロムメッキ鋼板が開発さ
れてきた。これは、鋼板の表面に錫またはニッケルの皮
膜をつくり、その上に金属クロム、水和酸化クロムの皮
膜を施して製造されている。上述のように薄クロムメッ
キ鋼板の製造にあたっては、重クロム酸ソーダ水溶液を
用い、電解クロメート処理を行っているが、クロメート
処理後の鋼板は大量の水で洗浄される。このときの排水
は６価クロムを含有する酸性排水である（以下、クロム
リンスと称する）。この排水の無害化処理法としては、
亜硫酸水素ナトリウムや塩化第１鉄溶液を用いての還元
処理と消石灰等のアルカリ剤による中和を行い、水酸化
物として沈殿・分離し、無害化処理を行なっている。On the other hand, in recent years, a thin chromium-plated steel sheet has been developed as a welding can material replacing tinplate (tin-plated steel sheet). It is manufactured by forming a coating of tin or nickel on the surface of a steel sheet, and then applying a coating of chromium metal or hydrated chromium oxide on it. As described above, in producing a thin chromium-plated steel sheet, an electrolytic chromate treatment is performed using an aqueous solution of sodium bichromate, but the steel sheet after the chromate treatment is washed with a large amount of water. The wastewater at this time is an acidic wastewater containing hexavalent chromium (hereinafter, referred to as chrome rinse). As a method of detoxifying this wastewater,
A reduction treatment using sodium hydrogen sulfite or a ferrous chloride solution and a neutralization with an alkali agent such as slaked lime are performed to precipitate and separate as a hydroxide, thereby performing a detoxification treatment.
【０００５】また、クロメート処理浴槽の重クロム酸ソ
ーダ水溶液は定期的に補充、入替えが必要となる。液の
補充、入替えに際し発生する濃厚廃液はクロムダンプ液
と呼ばれ水洗排水とは別に処理されている。すなわち、
クロムダンプ液をタンク、ピット等に受入れ、塩化第１
鉄溶液、硫酸鉄溶液等で還元処理を行った後、消石灰、
苛性ソーダ等のアルカリ剤にて中和し、金属水酸化物と
して沈殿・分離し、無害化処理を行なっている。Further, the aqueous solution of sodium bichromate in the chromate treatment bath needs to be periodically refilled and replaced. The concentrated waste liquid generated when replenishing and replacing the liquid is called a chrome dump liquid and is treated separately from the washing wastewater. That is,
Receive chromium dump solution into tanks, pits, etc.
After reduction treatment with iron solution, iron sulfate solution, etc., slaked lime,
Neutralized with an alkaline agent such as caustic soda, precipitated and separated as metal hydroxide, and detoxified.
【０００６】一方で自動車用鋼板等に用いられる鋼板の
電気亜鉛メッキ工程（以下、ＥＧＬと称する）において
は、メッキ浴として硫酸に亜鉛粒と鉄粒を溶解し、２価
の鉄・亜鉛共に飽和させた状態で使用している。亜鉛メ
ッキされた鋼板類は仕上げに水洗されるが、この水洗排
水はリンス排水と呼ばれ亜鉛及び２価の鉄を含んだ酸性
廃液である。また、メッキ浴は定期的に浴液交換を行う
必要があり、この交換時には亜鉛及び鉄が濃厚なダンプ
廃液と呼ばれる硫酸酸性廃液が排出される。金属製品工
場では電気亜鉛メッキ鋼板のみならず、電気合金亜鉛メ
ッキ鋼板、二層メッキ鋼板と呼ばれる種々の表面処理鋼
板が製造されている。以下に、これら表面処理鋼板の製
造工程において排出される水洗排水を総称してＥＧＬリ
ンス排水、濃厚なダンプ廃液をＥＧＬダンプ液と称す
る。On the other hand, in an electrogalvanizing step (hereinafter referred to as EGL) of a steel sheet used for a steel sheet for an automobile or the like, zinc particles and iron particles are dissolved in sulfuric acid as a plating bath, and both divalent iron and zinc are saturated. It is used in a state where it has been let. Galvanized steel sheets are washed with water in finishing, and the washing wastewater is called a rinse wastewater and is an acidic wastewater containing zinc and divalent iron. Further, it is necessary to periodically exchange the bath liquid for the plating bath, and at the time of this exchange, a sulfuric acid acid waste liquid called a dump waste liquid rich in zinc and iron is discharged. In metal products factories, not only electrogalvanized steel sheets but also various surface-treated steel sheets called electroalloy galvanized steel sheets and double-layer galvanized steel sheets are manufactured. Hereinafter, the washing wastewater discharged in the production process of these surface-treated steel sheets is collectively referred to as EGL rinse wastewater, and the concentrated dump wastewater is referred to as EGL dumpwater.
【０００７】リンス排水は空気ばっ気により２価の鉄を
酸化し、消石灰、苛性ソーダ等のアルカリ剤で中和して
３価の鉄水酸化物として沈殿分離している。濃厚なＥＧ
Ｌダンプ液においては空気ばっ気では酸化力が弱いこと
から、リンス排水処理設備に余力が十分あれば別だが、
リンス排水と併せて処理するには量的な制約がある。リ
ンス排水処理設備で処理困難なＥＧＬダンプ液は別途処
理をおこなっているのが現状である。すなわち、タンク
等に受け入れたＥＧＬダンプ液中の２価の鉄量を測定
し、過酸化水素等の強酸化剤を添加して酸化を行い、し
かる後に苛性ソーダ、消石灰等のアルカリ剤を添加して
水酸化物の沈殿を生成させた後、分類・脱水処理してい
る。[0007] Rinsing wastewater oxidizes divalent iron by aeration of air, and is neutralized with an alkaline agent such as slaked lime or caustic soda to precipitate and separate as trivalent iron hydroxide. Rich EG
Since the oxidizing power of L-dump solution is weak when air is aerated, it is not necessary if the rinsing wastewater treatment facilities have sufficient capacity.
There is a quantitative limitation to treat it together with rinse drainage. At present, the EGL dump solution that is difficult to treat in the rinse wastewater treatment facility is separately treated. That is, the amount of divalent iron in the EGL dump solution received in the tank or the like is measured, a strong oxidizing agent such as hydrogen peroxide is added to perform oxidation, and then an alkali agent such as caustic soda and slaked lime is added. After forming hydroxide precipitates, they are classified and dehydrated.
【０００８】このように従来においては、図２に示すよ
うに各々の工程より発生する廃液を各々の設備にて処理
を行っているものである。すなわち、図２は従来法によ
る各処理系統図であり、図２（ａ）はクロムダンプ液還
元中和処理系を示すもので、クロムダンプ液は塩化第１
鉄水溶液を用いて還元処理する。また、図２（ｂ）はＥ
ＧＬダンプ酸化中和処理系を示し、リンス排水処理設備
で処理不可能なＥＧＬダンプ液は過酸化水素で酸化処理
した後、アルカリ剤で中和し、金属水酸化物として析出
・凝集させて無害化処理を行い凝集汚泥は脱水処理して
いる。さらに、図２（ｃ）はリンス排水処理系統図であ
り、リンス排水にＥＧＬダンプ液を加え、空気酸化した
後にアルカリ剤で中和し、金属水酸化物として凝集沈澱
処理している。As described above, conventionally, as shown in FIG. 2, waste liquid generated from each process is processed in each facility. That is, FIG. 2 is a diagram of each treatment system according to the conventional method, and FIG. 2 (a) shows a chromium dump solution reduction neutralization treatment system.
Reduction treatment is performed using an aqueous iron solution. FIG. 2B shows E
Shows GL dump oxidation neutralization system. EGL dump solution that cannot be treated by rinsing wastewater treatment equipment is oxidized with hydrogen peroxide, then neutralized with an alkali agent, deposited and aggregated as metal hydroxide, and is harmless. Coagulation sludge is dehydrated. Further, FIG. 2 (c) is a rinse drainage treatment system diagram, in which an EGL dump solution is added to the rinse wastewater, air-oxidized, neutralized with an alkali agent, and subjected to coagulation and precipitation as a metal hydroxide.
【０００９】[0009]
【発明が解決しようとする課題】上述したように、溶接
用缶材料や自動車用鋼板を製造する金属製品工場におい
ては、それぞれの用途に応じた鋼板の表面処理を行なっ
ている。表面処理後の水洗排水はその性状に応じて、通
常のリンス排水処理施設で空気酸化処理及び薬剤による
還元処理を行った後、アルカリ剤を添加して水酸化物と
して重金属を沈殿分離することが容易であるが、メッキ
浴槽の入替え廃液等は濃厚な重金属を含有していること
から、リンス排水処理施設とは別に、各々の性状に応じ
た処理施設・処理方法をとらざるを得なかった。そこ
で、本発明はこのような問題を解消し、酸化処理と還元
処理の必要な濃厚廃液を同時に処理するとともに、リン
ス排水処理設備を利用して表面処理工程から発生するリ
ンス排水とダンプ廃液の全てを、一つの設備で処理する
方法を提供するものである。As described above, in metal products factories that manufacture welding can materials and steel plates for automobiles, the surface treatment of the steel plates is performed according to the respective applications. Depending on the properties of the rinse water after surface treatment, after performing air oxidation treatment and chemical reduction treatment in a normal rinse wastewater treatment facility, an alkali agent is added to precipitate and separate heavy metals as hydroxide. Although it is easy, since the waste liquid for replacing the plating bath contains a heavy metal, a treatment facility and a treatment method according to each property must be taken separately from the rinsing wastewater treatment facility. Therefore, the present invention solves such a problem, and simultaneously treats the concentrated waste liquid requiring oxidation treatment and reduction treatment, and uses the rinse waste water treatment equipment to remove all of the rinse waste water and dump waste liquid generated from the surface treatment process. In a single facility.
【００１０】[0010]
【課題を解決するための手段】本発明は、重金属含有酸
性廃液を酸化または還元し、金属類をアルカリ中和剤を
添加し金属水酸化物として、凝集沈殿させることにより
廃水を無害化処理する方法において、濃厚なクロム酸含
有廃液及び濃厚な第１鉄含有廃液とを相互に酸化・還元
反応させた複合処理液に、メッキ鋼板のリンス排水及び
第１鉄含有廃液とともに、アルカリ剤で中和し、水酸化
物として凝集沈殿させる、鋼板類のメッキ廃液の処理方
法である。また本発明は各種の表面処理鋼板を製造する
金属製品工場からの濃厚廃液、すなわち濃厚クロム酸含
有廃液がクロムメッキ処理工程またはクロメート処理工
程の浴槽から排出される廃液であり、濃厚な第１鉄含有
廃液が電気亜鉛メッキ浴廃液であることが特徴である。SUMMARY OF THE INVENTION The present invention oxidizes or reduces a heavy metal-containing acidic waste liquid and adds an alkali neutralizing agent to the metal to form a metal hydroxide, thereby coagulating and sedimenting the wastewater to detoxify the wastewater. In the method, the combined treatment liquid obtained by mutually oxidizing and reducing the concentrated chromic acid-containing waste liquid and the concentrated ferrous iron-containing waste liquid is neutralized with an alkali agent together with the rinse wastewater of the plated steel sheet and the ferrous iron-containing waste liquid. This is a method for treating a plating waste liquid for steel sheets, which is then coagulated and precipitated as a hydroxide. The present invention also relates to a concentrated waste liquid from a metal product factory for producing various surface-treated steel sheets, that is, a concentrated chromic acid-containing waste liquid discharged from a bathtub in a chromium plating step or a chromate treatment step. It is characterized in that the contained waste liquid is an electrogalvanizing bath waste liquid.
【００１１】[0011]
【発明の実施の形態】以下、本発明について詳細に説明
する。本発明においては、還元処理の必要なクロムダン
プ液と酸化処理の必要なＥＧＬダンプ液とを、同一のタ
ンクもしくはピットに受入れ、強力な酸化力をもつクロ
ムダンプ液を濃厚なＥＧＬダンプ液の第１鉄で相互に酸
化還元反応を行わせるものである。このように、クロム
ダンプ液の還元処理とＥＧＬダンプ液の酸化処理を両者
によって同時処理が可能となり、しかも、これらの両者
廃液の有する特有な成分がそれぞれ両者の反応速度を速
める相乗効果として働くことにある。そして、酸化還元
反応後の液については通常のリンス排水と併せて処理す
ることが可能であることから、消石灰、水酸化マグネシ
ウム等のアルカリ剤により中和し、金属水酸化物として
沈殿分離処理することができる。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, a chromium dump solution requiring a reduction treatment and an EGL dump solution requiring an oxidation treatment are received in the same tank or pit, and a chromium dump solution having a strong oxidizing power is converted into a concentrated EGL dump solution. The oxidation and reduction reactions are mutually performed with iron. As described above, both the reduction treatment of the chromium dump solution and the oxidation treatment of the EGL dump solution can be performed simultaneously, and the unique components of these waste liquids have a synergistic effect of increasing the reaction speed of both. It is in. Then, since the liquid after the oxidation-reduction reaction can be treated together with ordinary rinse wastewater, it is neutralized with an alkali agent such as slaked lime or magnesium hydroxide, and subjected to precipitation separation treatment as a metal hydroxide. be able to.
【００１２】このような処理をすることによって、従
来、濃厚なクロムダンプ液はリンス排水とは別に処理さ
れていたし、濃厚なＥＧＬダンプ液についても同様に、
リンス排水とは別に処理されている。また、クロムダン
プ液等は６価クロムを大量に含有しているため、中和凝
集処理に際して事前に還元処理を行う必要があり、ＥＧ
Ｌダンプ液は第１鉄を大量に含有しているので、中和凝
集処理に際して事前に強酸化剤を用いて第２鉄に酸化処
理を行う必要があったものが、本発明によって、このよ
うな処理は全く必要がなくなり、しかも、酸化・還元を
各々別々に行う場合に比べ、反応速度も速められ短時間
処理が可能となった。[0012] By performing such treatment, conventionally, the concentrated chromium dump solution has been treated separately from the rinse drainage.
It is treated separately from the rinse drainage. Further, since the chromium dump solution and the like contain a large amount of hexavalent chromium, it is necessary to perform a reduction treatment in advance during the neutralization aggregation treatment.
Since the L dump solution contains a large amount of ferrous iron, it was necessary to oxidize ferric iron using a strong oxidizing agent before neutralization and coagulation treatment. No treatment is required at all, and the reaction speed is increased as compared with the case where oxidation and reduction are performed separately, so that treatment can be performed in a short time.
【００１３】以下、実施例によって、さらに本発明につ
いて具体的に説明する。図１は本発明に係る処理系統図
である。この図１に示すように、クロメート処理浴槽か
ら発生するクロムダンプ液及び電気亜鉛めっき浴槽から
の濃厚なＥＧＬダンプ液を複合処理した廃液とを相互に
酸化・還元反応させるものである。この場合のクロムダ
ンプ液及びＥＧＬダンプ液を表１に示す。クロム酸は公
害対策上、全て３価のクロムに還元する必要があること
から、クロムダンプ液は全量を還元槽にてＥＧＬダンプ
液を添加して還元した（以下、複合処理と称する）。上
記複合処理液及び余剰分のＥＧＬダンプ液を従来同様に
リンス排水と併せ処理を行った。その結果を表２に示
す。従来はクロムダンプ液の還元に使用していた塩化第
１鉄及びＥＧＬダンプの酸化に使用していた過酸化水素
が不要となり、処理工程も簡略化することが可能となっ
た。また、塩化第１鉄の使用が不要となった分、塩化第
１鉄に起因する脱水ケーキ量も減少した。Hereinafter, the present invention will be described more specifically with reference to examples. FIG. 1 is a processing system diagram according to the present invention. As shown in FIG. 1, a chromium dump solution generated from a chromate treatment bath and a waste solution obtained by compounding a concentrated EGL dump solution from an electrogalvanizing bath are subjected to an oxidation and reduction reaction with each other. Table 1 shows the chromium dump solution and the EGL dump solution in this case. Since it is necessary to reduce all chromic acid to trivalent chromium for pollution control, the entire chromium dump solution was reduced by adding an EGL dump solution in a reduction tank (hereinafter, referred to as a composite treatment). The combined treatment solution and the excess EGL dump solution were treated together with the rinse drainage in the same manner as before. Table 2 shows the results. Conventionally, ferrous chloride which has been used for reducing the chromium dump solution and hydrogen peroxide which has been used for oxidizing the EGL dump have become unnecessary, and the processing steps can be simplified. In addition, the amount of dehydrated cake caused by ferrous chloride also decreased because the use of ferrous chloride became unnecessary.
【００１４】[0014]
【表１】 [Table 1]
【００１５】[0015]
【表２】 [Table 2]
【００１６】表２に示すように本発明の方法によれば、
濃厚なＥＧＬダンプ液及びクロムダンプ液を複合処理し
た廃液を、通常のリンス排水と混合処理することが可能
である。またリンス排水中の亜鉛分も濃厚な鉄分と共沈
することから、従来に比べ低ｐＨ域でも処理が可能とな
り、リンス排水処理性が向上した。処理水性状も排水基
準を十分に満たすことができた。そこで、従来の処理法
と本発明の方法を処理性で比較した結果を表３に示す。According to the method of the present invention as shown in Table 2,
It is possible to mix and treat the waste liquid obtained by compounding the concentrated EGL dump liquid and the chrome dump liquid with ordinary rinse drainage. Further, since zinc in the rinse wastewater is co-precipitated with the rich iron, treatment can be performed even in a low pH range as compared with the conventional method, and the rinse wastewater treatment property is improved. The treated water quality was able to sufficiently satisfy the drainage standard. Therefore, Table 3 shows the results of comparison between the conventional processing method and the method of the present invention in terms of processing performance.
【００１７】表３の結果から判るように、本発明の方法
によればクロムダンプ液還元用の塩化第１鉄及びＥＧＬ
ダンプ液酸化用の過酸化水素が不要となった結果、廃液
・排水の単位処理量あたりの薬剤使用量が減り、発生汚
泥（脱水ケーキ）の減量化及びコスト削減に寄与してい
る。また処理水の鉄及び亜鉛濃度も低くなり処理性が向
上した。As can be seen from the results in Table 3, according to the method of the present invention, ferrous chloride and EGL for reducing chromium dump solution are used.
As a result of the elimination of the need for hydrogen peroxide for oxidizing the dump liquid, the amount of chemicals used per unit treatment amount of waste liquid and wastewater is reduced, contributing to a reduction in the amount of generated sludge (dewatered cake) and cost reduction. Also, the iron and zinc concentrations of the treated water were reduced and the treatability was improved.
【００１８】[0018]
【表３】 [Table 3]
【００１９】[0019]
【発明の効果】以上述べたように、従来は濃厚なクロム
酸廃液と第１鉄系廃液を各々別々に還元処理、酸化処理
していたが、本発明によるメッキ廃液処理を行えば、濃
厚廃液どうしを相互に酸化還元処理することが可能であ
る。また、リンス排水と別個に処理していた濃厚廃液を
リンス排水と同時に処理することも可能となり、リンス
排水処理系、クロム酸還元処理系及び酸化中和処理系と
３系統のメッキ廃液処理設備が必要であったものが、酸
化還元同時処理タンクとリンス排水処理系設備のみで処
理することが可能である。さらに、還元剤として使用し
ていた塩化第１鉄及び酸化剤として使用していた過酸化
水素が不要となることから、経済効果があがることはい
うまでもない。As described above, conventionally, a concentrated chromic acid waste liquid and a ferrous waste liquid have been separately reduced and oxidized, but if the plating waste liquid treatment according to the present invention is performed, the concentrated waste liquid can be concentrated. It is possible to redox each other. In addition, it is possible to treat the concentrated waste liquid that had been treated separately from the rinsing wastewater at the same time as the rinsing wastewater. What was needed can be treated only by the simultaneous oxidation-reduction treatment tank and the rinse wastewater treatment system. Further, since ferrous chloride used as a reducing agent and hydrogen peroxide used as an oxidizing agent are not required, it goes without saying that the economic effect is improved.
【図１】本発明に係る処理系統図である。FIG. 1 is a processing system diagram according to the present invention.
【図２】従来法による各処理系統図である。FIG. 2 is a diagram of each processing system according to a conventional method.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 橋本 健二 愛知県東海市東海町５−３ 新日本製鐵株 式会社名古屋製鐵所内 (72)発明者 湯浅 武士 愛知県東海市東海町５−３ 新日本製鐵株 式会社名古屋製鐵所内 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kenji Hashimoto 5-3 Tokaicho, Tokai City, Aichi Prefecture Inside Nagoya Works, Nippon Steel Corporation (72) Inventor Takeshi Yuasa 5-3 Tokaicho, Tokai City, Aichi Prefecture Nippon Steel Corporation Nagoya Works
Claims (3)
し、金属類をアルカリ剤の添加により中和し、金属水酸
化物として凝集沈殿・分離させることにより廃水を無害
化処理する方法において、濃厚なクロム酸含有廃液及び
第１鉄含有廃液とを相互に酸化・還元反応させた複合処
理液に、メッキ鋼板の水洗弱酸性排水及び第１鉄含有廃
液とともに、アルカリで中和し、水酸化物として凝集沈
殿させることを特徴とする、鋼板類のメッキ廃液の処理
方法。A method for detoxifying wastewater by oxidizing or reducing heavy metal-containing acidic wastewater, neutralizing metals by adding an alkali agent, and coagulating, sedimenting and separating as metal hydroxide. A complex treatment solution, in which chromic acid-containing waste liquid and ferrous iron-containing waste liquid are mutually oxidized and reduced, is neutralized with alkali together with a weakly acidic wastewater and ferrous-containing waste liquid for washing of plated steel sheets to form hydroxides. A method for treating wastewater from plating of steel sheets, comprising coagulating and sedimenting.
理工程またはクロメート処理工程の浴槽から排出される
廃液である請求項１記載の鋼板類のメッキ廃液の処理方
法。2. The method according to claim 1, wherein the concentrated chromic acid-containing waste liquid is a waste liquid discharged from a bath in a chromium plating step or a chromate treatment step.
キ浴廃液である請求項２記載の鋼板類のメッキ廃液の処
理方法。3. The method for treating a steel plate plating waste liquid according to claim 2, wherein the concentrated ferrous iron-containing waste liquid is mainly an electrogalvanizing bath waste liquid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8545797A JPH10277565A (en) | 1997-04-04 | 1997-04-04 | Method for treating waste liquid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8545797A JPH10277565A (en) | 1997-04-04 | 1997-04-04 | Method for treating waste liquid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10277565A true JPH10277565A (en) | 1998-10-20 |
Family
ID=13859419
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8545797A Withdrawn JPH10277565A (en) | 1997-04-04 | 1997-04-04 | Method for treating waste liquid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10277565A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109052711A (en) * | 2018-08-16 | 2018-12-21 | 武汉钢铁有限公司 | The innoxious and resource utilization method of steel and iron industry chromate waste water |
| CN112062411A (en) * | 2020-09-11 | 2020-12-11 | 深圳市粤昆仑环保实业有限公司 | Electroplating sewage treatment method |
-
1997
- 1997-04-04 JP JP8545797A patent/JPH10277565A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109052711A (en) * | 2018-08-16 | 2018-12-21 | 武汉钢铁有限公司 | The innoxious and resource utilization method of steel and iron industry chromate waste water |
| CN112062411A (en) * | 2020-09-11 | 2020-12-11 | 深圳市粤昆仑环保实业有限公司 | Electroplating sewage treatment method |
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