JP4233923B2 - Treatment agent for heavy metal contaminated soil and soil treatment method using the same - Google Patents
Treatment agent for heavy metal contaminated soil and soil treatment method using the same Download PDFInfo
- Publication number
- JP4233923B2 JP4233923B2 JP2003152253A JP2003152253A JP4233923B2 JP 4233923 B2 JP4233923 B2 JP 4233923B2 JP 2003152253 A JP2003152253 A JP 2003152253A JP 2003152253 A JP2003152253 A JP 2003152253A JP 4233923 B2 JP4233923 B2 JP 4233923B2
- Authority
- JP
- Japan
- Prior art keywords
- solidifying agent
- cement
- gypsum
- lime
- agent
- 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.)
- Expired - Lifetime
Links
Landscapes
- Processing Of Solid Wastes (AREA)
- Soil Conditioners And Soil-Stabilizing Materials (AREA)
Description
【0001】
【発明の属する技術分野】
本発明は、重金属を含有する土壌に添加して用いる重金属含有汚染土壌用処理剤、及びそれを用いて重金属の溶出量を環境基準値以下にする土壌処理方法に関する。
【0002】
【従来の技術】
従来、重金属例えば水銀、鉛、クロム、砒素、カドミウム、セレンによる汚染土壌を薬剤添加によって処理方法としては、ジチオカルバミン酸塩に代表される合成キレート剤を用いる方法、硫化ナトリウム、及び各種燐酸塩、鉄塩に代表される無機塩を用いる方法、あるいはセメントなどの固化剤を用いる方法が行われている。
【0003】
しかし、上述の処理方法によっても、土壌からの重金属の溶出を確実に抑えることが出来なかった。その原因は、多くの汚染土壌が、シルト及び粘土分を含有しており、これらの含有成分は活性度の高い表面積の大きいコロイド粒子を含んでおり、その表面に、重金属類が吸着あるいはイオン交換した状態で存在しているため、添加された合成キレート剤が重金属類と有効に反応しないこと、及び土壌中の有機物と重金属が複合体を形成しているために、重金属と合成キレート剤の反応が進行し難くなっていることがあると考えられている。
【0004】
これを解決するために、多量の酸化剤で土壌を酸化したのちに、キレート剤で処理するという処理方法が提案されている。しかし、この方法は、コストが非常に高く、また、合成キレート剤は、高価格であり、かつ多量の汚染土壌を処理するには問題が有る。例えばチオカルバミン酸系キレート剤及び硫化ナトリウムを用いると、土壌が弱酸性の場合に、二硫化炭素、硫化水素臭が発生したり、セメント等の高アルカリ固化剤と併用した場合に、アミンガスを発生するので、環境上の問題が生じることも指摘されている。
また、無機塩、固化剤を用いる単独処理方法によると、特定の金属に対する効果が低いなどの問題がある。
【0005】
【発明が解決しようとする課題】
本発明は、重金属汚染土壌から重金属が溶出することを効率よく防止することができる重金属汚染土壌用の処理剤を提供することを目的とする。
【0006】
【課題を解決するための手段】
本発明者らは、鋭意検討した結果、この目的を達成しうる重金属汚染土壌処理剤を見い出した。本発明の処理剤は、フミン酸と特定の固化剤を主成分とするか、またはフミン酸と固化剤を配合し、これに特定の二酸化珪素、水溶性燐酸、水溶性燐酸塩から選ばれる1種類以上含むものである。中でも、フミン酸、二酸化珪素、固化剤からなるもの、及びフミン酸、水溶性燐酸塩、固化剤からなるものが好ましい。
本発明の処理剤の対象となるのは土壌であり、重金属、例えば水銀、鉛、クロム、砒素、カドミウム、セレン、フッ素、ホウ素で汚染された土壌である。
【0007】
本発明の処理剤の特徴は、フミン酸及びその塩(フミン酸と総称する)と固化剤を併用することにある。フミン酸は、その分子内にはヒドロキシル基、ニトロソ基、カルボキシル基を有しており、キレート能とイオン交換能を持ち合わせた化合物であると推定される。その一部は、水可溶のフルボン酸等の低分子量化合物を含むが、殆ど水不溶の化合物である。
フミン酸を単独で汚染土壌処理に用いた場合、フミン酸は水不溶の重金属錯体を形成し、土壌中に固定化されるが、フミン酸に含まれる低分子量の化合物が水に溶け出し、フミン酸塩を用いた場合は、その一部が水に溶け出すために、重金属の溶出量を増加させることもあった。
【0008】
しかし、このような可溶性のフミン酸であっても重金属と反応し、金属錯体を形成していることは分かっている。また、金属錯体を形成しているフミン酸溶液にカルシウム、アルミニウムを含む無機塩を添加することにより、フミン酸重金属錯体が、不溶性の凝集コロイドを形成することは知られている。
【0009】
したがって、汚染土壌にフミン酸を添加し、錯体を形成した状態において、これに固化剤を併用すれば、固化剤中のカルシウム、アルミニウムの影響で、フミン酸重金属錯体が、不溶性のコロイドになり、固化剤のエトリンガイト、ポゾラン反応により、形成される結晶構造に錯体の状態で封じ込められると推定される。また、フミン酸に固化剤を併用すると、従来、セメント、石灰で固化処理できなかった鉛汚染土壌を処理することができ、即効性と長期安定性の両方を兼ね備えた処理物を得ることができる。
【0010】
上記のフミン酸と固化剤に対して、比表面積の大きい二酸化珪素を併用すると、二酸化珪素が直接重金属を吸着したり、フミン酸−重金属錯体を吸着した状態で、固化剤のエトリンガイト・ポゾラン反応により形成される結晶構造に封じ込められると思われ、フミン酸と二酸化珪素によって、処理直後の重金属固定化を達成し、固化剤で長期的に安定化を図ることができる。
燐酸塩を併用した場合は、混合されている燐酸と重金属とが直接反応し、不溶性化合物を形成するばかりでなく、これに石灰系固化剤を併用することにより、長期的には、ヒドロキシアパタイト鉱物を形成し、フミン酸重金属錯体を鉱物中に取りこみ、重金属の固定化を長期的に安定化させる。
鉄塩を併用した場合は、フミン酸と鉄イオンが反応し、フミン酸及び低分子量のフルボ酸などが重金属と結合したまま凝集し不溶化するため、再溶出を防ぐ効果がある。また、汚染物質である砒素及びセレンが砒酸、亜ヒ酸、セレン酸の形でイオン化している場合は、鉄イオンと反応し、不溶性の砒酸鉄などの鉄化含物を形成し、フミン酸に吸着し、固化剤により土粒子と共に固化される。
【0011】
本発明で、使用するフミン酸は、天然フミン酸、ニトロフミン酸、ニトロフミン酸ナトリウム塩、ニトロフミン酸カリウム塩、ニトロフミン酸マグネシウム塩に代表されるフミン酸化合物であれば何れを用いても良い。中でもニトロフミン酸を使用することが最も好ましい。
固化剤は、ポルトランドセメント、高炉セメント、早強セメント、無水石膏、二水石膏、半水石膏、消石灰、石灰、セメント系固化剤である。セメント系固化剤としては、例えば住友大阪セメント(株)の「タフロック」、石膏系固化剤としては、例えば石原産業(株)の「ジプサンダー」、石灰系固化剤としては、例えば奥多摩工業(株)の「マスターズ」の何れかであればよく、特に制限されない。(括弧内は、いずれも商品名)
二酸化珪素は、嵩比重0.05(g/ml)以上で、かつ、比表面積30(m2/g)以上の粉体状のものであれば何れでも良いが、比表面積が200(m2/g)以上の粉末品を使用することが最も好ましい。
【0012】
燐酸塩は、燐酸水素2ナトリウム、燐酸ナトリウム、燐酸2水素ナトリウム、ポリ燐酸ナトリウムに代表される水溶性燐酸塩であれば、特に制限されるものではない。中でも、燐酸水素2ナトリウムを使用するのが最も好ましい。
鉄塩は、塩化第一鉄、塩化第二鉄、硫酸第一鉄、硫酸第二鉄を含む水溶性鉄塩であれば特に制限されるものではないが、硫酸第一鉄を使用することが好ましい。
【0013】
本発明の重金属含有汚染土壌用処理剤(以下処理剤ともいう)の添加に当っては、汚染土壌に処理剤とともに水を加えて処理することが、土壌と処理剤の接触効率を高める上で有効である。使用する処理剤の種類及び配合比は、請求項1、3〜7に記載されているとおりであり、以下の添加量範囲で使用することが最も好ましい。
【0014】
(1)フミン酸と固化剤を併用する場合
フミン酸と固化剤を重量比で1/35から1/3の範囲で使用する。固化剤の配合量が、これ以下になると処理土から、フミン酸が溶出してくる場合がある。また、固化剤の配合量がこれ以上になると、フミン酸の配合量が少くなり、重金属の固定化効果が低下する。
(2)フミン酸と二酸化珪素混合物と固化剤を併用する場合
フミン酸と二酸化珪素の2成分からなり、フミン酸と二酸化珪素の配合比が重量比で3/1〜1/1であり、この2成分混合物と固化剤を、重量比で1/35〜2/1の範囲で使用する。この範囲から外れた場合は、処理土から、フミン酸が溶出してきたり、重金属の固定化効果が低下する場合がある。
【0015】
(3)フミン酸と燐酸塩混合物と固化剤を併用する場合
フミン酸と水溶性燐酸塩の2成分からなり、フミン酸と水溶性燐酸塩の配合比が重量比6/1〜1/1であり、この2成分混合物と固化剤を、重量比で1/35〜2/1の範囲で使用する。この範囲から外れた場合は、処理土から、フミン酸が溶出してきたり、重金属の固定化効果が低下する場合がある。
(4)フミン酸と鉄塩と固化剤を併用する場合
フミン酸と水溶性鉄塩の2成分からなり、フミン酸と水溶性鉄塩の配合比が重量比で6/1〜1/1であり、この2成分混合物と固化剤を、重量比で1/35から2/1の範囲で使用する。この範囲を外れた場合は、処理土から、フミン酸が溶出してきたり、重金属の固定化効果が低下する場合がある。
(5)フミン酸、二酸化珪素、燐酸塩混合物と固化剤を併用する場合
フミン酸、二酸化珪素、水溶性燐酸塩の3成分配合比が、フミン酸の含有量5重量部〜60重量部、他の2成分の含有量が95重量部〜40重量部の範囲で任意に設定される。この3成分混合物と固化剤は、配合比が重量比で1/35から2/1の範囲で使用する。この範囲から外れた場合は、処理土から、フミン酸が溶出したり、重金属の固定化効果が低下する場合がある。
(6)フミン酸、燐酸塩、鉄塩混合物と固化剤を併用する場合
フミン酸、水溶性燐酸塩、水溶性鉄塩の3成分配合比が、フミン酸含有量5重量部〜60重量部、他の2成分の含有量が95重量部〜40重量部の範囲で任意に設定される。この3成分混合物と固化剤は、配合比が重量比で1/35から2/1の範囲で使用する。この範囲から外れた場合は、処理土から、フミン酸が溶出してきたり、重金属の固定化効果が低下する場合がある。
【0016】
【実施例】
以下に実施例及び比較例を挙げて本発明についてさらに具体的に説明するが、本発明は、これに限定されるものではない。
なお、実施例や比較例において、フミン酸は、ニトロフミン酸を使用し、二酸化珪素は、日本シリカ工業(株)の「ニップシールCX200」(商品名)を使用した。「ニップシールCX2000」は、嵩比重0.05(g/ml)以上で比表面積30(m 2 /g)以上の粉末状のものである。また、固化剤、燐酸塩は、工業用製品を用いた。
【0017】
【実施例1〜4】
【比較例1,2】
模擬鉛汚染土壌に本発明の土壌用処理剤を添加、混合した。その結果を表−1に示す。試験手順及び模擬汚染土壌の配合割合は、以下の通りである。
汚染土壌配合組成:
関東ローム層と砂を重量比5:5で混合した土壌を使用し、混合土壌1kg当りの鉛含有量を40mg(硝酸鉛で調整)、含水率27%とした。
試験手順:
(1)汚染土壌に処理剤を所定量添加し、ガラス棒で良く混合したのち、一晩放置した。(2) 環境庁告示46号の方法に基づいて溶出試験を実施し、原子吸光光度法により鉛溶出量(mg/L)を求めた。
【表1】
本発明の処理剤を用いた場合、鉛の溶出量は、鉛の土壌環境基準値である0.01(mg/L)以下を十分に満足しているのに対し、セメント単独処理した場合は、基準値を大幅に上まわる値になり、本固定化剤が優れた性能を有することが分かる。
【0018】
【実施例5〜6】
【比較例3〜4】
模擬カドミウム汚染土壌に本発明の処理剤を添加、混合した。結果を表−2に示す。なお、模擬汚染土壌配合は、以下の通りである。また、測定手順は実施例1と同様である。汚染土壌配合組成:
関東ローム層と砂を重量比4:6で混合した土壌を使用し、混合土壌1kg当りのカドミウム含有量を500mg(硝酸カドミウム四水和物で調整)、含水率27%とした。
【表2】
本発明の処理剤を用いた場合、カドミウムの溶出量は、カドミウムの土壌環境基準値である0.01(mg/L)以下を十分に満足しているのに対し、石膏単独処理又はフミン酸を用いなかった場合は、基準値を大幅に上まわる値になり、本固定化剤が優れた性能をもつことが分かる。
【0019】
【実施例7〜9】
【比較例5〜6】
模擬鉛汚染土壌に本発明の処理剤を添加、混合した。その結果を表−3に示す。模擬汚染土壌配合は、以下の通りである。また、測定手順は実施例1と同様である。
汚染土壌配合組成:
関東ローム層と砂を重量比5:5で混合した土壌を使用し、混合土壌1kg当りの鉛含有量を4000mg(硝酸鉛で調整)、含水率27%とした。
【表3】
本発明の処理剤を用いた場合、鉛の溶出量は、鉛の土壌環境基準値である0.01(mg/L)以下を十分に満足しているのに対し、セメント単独処理し又はフミン酸を用いなかった場合は、基準値を大幅に上まる値になり、本固定化剤が優れた性能を有することが分かる。
【0020】
【実施例10〜11】
【比較例7〜11】
A市現場土壌に対する重金属固定化剤の効果に関する試験結果を表−4に示す。なお、測定手順は実施例1と同様である。
比較例として、O社液体キレート品、二酸化珪素単独、二酸化珪素+石膏系固化剤、二酸化珪素+セメント及びセメント単独処理を用いた試験結果も併せて示す。表4中、石膏系固化剤として、石原産業(株)の「ジプサンダー」を用いた。
【0021】
【表4】
本発明の処理剤を用いた場合、総水銀、鉛、砒素の溶出量は、総水銀、鉛、砒素の土壌環境基準値である0.0005、0.01、0.01(mg/L)以下を十分に満足しているのに対し、液体キレート剤及びセメント単独処理した場合は、基準値を大幅に上まわる値になり、本固定化剤が優れた性能を有することが分かる。
【0022】
【実施例12、13】
【比較例12、13】
T市現場土壌に対する重金属固定化剤の効果に関する試験結果を表−5に示す。なお、測定手順は実施例1と同様である。比較例として硫酸第一鉄単独処理の試験結果も併せて記す。
表5中、石膏系固化剤としては、石原産業(株)の「ジプサンダー」を用いた。
【表5】
本発明の処理剤を用いた場合は、砒素の溶出量が多い汚染土壌に対しても土壌環境基準値以下に処理できることが分かる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a treatment agent for heavy metal-containing contaminated soil used by adding to soil containing heavy metal, and a soil treatment method using the amount of elution of heavy metal below an environmental standard value.
[0002]
[Prior art]
Conventionally, methods for treating soil contaminated with heavy metals such as mercury, lead, chromium, arsenic, cadmium and selenium by adding chemicals include methods using synthetic chelating agents typified by dithiocarbamate, sodium sulfide, and various phosphates, iron A method using an inorganic salt typified by a salt or a method using a solidifying agent such as cement has been performed.
[0003]
However, even with the above-described treatment method, elution of heavy metals from the soil could not be reliably suppressed. The cause is that many contaminated soils contain silt and clay, and these components contain highly active colloidal particles with a large surface area, and heavy metals are adsorbed or ion-exchanged on the surface. Since the added synthetic chelating agent does not react effectively with heavy metals and the organic matter and heavy metal in the soil form a complex, the reaction between the heavy metal and the synthetic chelating agent Is thought to be difficult to progress.
[0004]
In order to solve this, a treatment method has been proposed in which the soil is oxidized with a large amount of an oxidizing agent and then treated with a chelating agent. However, this method is very expensive, and synthetic chelating agents are expensive and problematic for treating large amounts of contaminated soil. For example, when a thiocarbamic acid chelating agent and sodium sulfide are used, when the soil is weakly acidic, carbon disulfide and hydrogen sulfide odors are generated, or when combined with a highly alkaline solidifying agent such as cement, amine gas is generated. Therefore, it has been pointed out that environmental problems will occur.
In addition, according to the single treatment method using an inorganic salt and a solidifying agent, there are problems such as low effect on a specific metal.
[0005]
[Problems to be solved by the invention]
An object of this invention is to provide the processing agent for heavy metal pollution soil which can prevent that a heavy metal elutes from heavy metal pollution soil efficiently.
[0006]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have found a heavy metal contaminated soil treatment agent that can achieve this object. The treatment agent of the present invention contains humic acid and a specific solidifying agent as main components, or contains humic acid and a solidifying agent, and is selected from specific silicon dioxide, water-soluble phosphoric acid, and water-soluble phosphate. Includes more than one type. Among these, those composed of humic acid, silicon dioxide and a solidifying agent, and those composed of humic acid, a water-soluble phosphate and a solidifying agent are preferable.
The target of the treatment agent of the present invention is soil, which is soil contaminated with heavy metals such as mercury, lead, chromium, arsenic, cadmium, selenium, fluorine and boron.
[0007]
The feature of the treatment agent of the present invention is that humic acid and a salt thereof (collectively referred to as humic acid) and a solidifying agent are used in combination. Humic acid has a hydroxyl group, a nitroso group, and a carboxyl group in the molecule, and is presumed to be a compound having both chelate ability and ion exchange ability. Some of them contain low molecular weight compounds such as water-soluble fulvic acid, but are almost water-insoluble compounds.
When humic acid is used alone for the treatment of contaminated soil, humic acid forms a water-insoluble heavy metal complex and is immobilized in the soil, but the low molecular weight compounds contained in humic acid dissolve in water and When an acid salt is used, a part of the acid salt dissolves in water, so that the amount of elution of heavy metal may be increased.
[0008]
However, it has been found that even such soluble humic acids react with heavy metals to form metal complexes. It is also known that a humic acid heavy metal complex forms an insoluble aggregated colloid by adding an inorganic salt containing calcium and aluminum to a humic acid solution forming a metal complex.
[0009]
Therefore, when humic acid is added to contaminated soil and a complex is formed, if a solidifying agent is used in combination with this, the heavy metal complex of humic acid becomes an insoluble colloid due to the influence of calcium and aluminum in the solidifying agent, It is presumed that the solidification agent ettringite and pozzolanic reaction can be contained in a complex state in the formed crystal structure. In addition, when a solidifying agent is used in combination with humic acid, it is possible to treat lead-contaminated soil that could not be solidified with cement and lime, and obtain a treated product that has both immediate effect and long-term stability. .
[0010]
When silicon dioxide with a large specific surface area is used in combination with the above humic acid and solidifying agent, silicon dioxide directly adsorbs heavy metals or adsorbs humic acid-heavy metal complexes by the ettringite-pozzolane reaction of the solidifying agent. It seems that it is confined in the formed crystal structure, and humic acid and silicon dioxide can achieve heavy metal immobilization immediately after the treatment and can be stabilized in the long term with a solidifying agent.
When the phosphate is used in combination, the mixed phosphoric acid and heavy metal react directly to form an insoluble compound, and in combination with a lime-based solidifying agent, a long-term hydroxyapatite mineral The humic acid heavy metal complex is incorporated into the mineral to stabilize the heavy metal for a long time.
When an iron salt is used in combination, humic acid and iron ions react, and humic acid and low molecular weight fulvic acid are aggregated and insolubilized while bound to heavy metal, so that there is an effect of preventing re-elution. In addition, when the pollutants arsenic and selenium are ionized in the form of arsenic acid, arsenous acid, and selenic acid, they react with iron ions to form iron-containing inclusions such as insoluble iron arsenate. And is solidified together with the soil particles by a solidifying agent.
[0011]
In the present invention, the humic acid to be used may be any humic acid compound represented by natural humic acid, nitrohumic acid, nitrohumic acid sodium salt, nitrohumic acid potassium salt, and nitrohumic acid magnesium salt. Of these, nitrohumic acid is most preferably used.
The solidifying agent is Portland cement, blast furnace cement, early strong cement, anhydrous gypsum, dihydrate gypsum, hemihydrate gypsum, slaked lime, lime, cement-based solidifying agent. For example, “Tough Rock” from Sumitomo Osaka Cement Co., Ltd., for example, “Gypsander” from Ishihara Sangyo Co., Ltd., for example, Okutama Kogyo Co., Ltd. Any of “Masters” in the above may be used, and there is no particular limitation. (All items in parentheses are product names)
The silicon dioxide may be any powdery material having a bulk specific gravity of 0.05 (g / ml) or more and a specific surface area of 30 (m 2 / g) or more, but the specific surface area is 200 (m 2). / G) It is most preferable to use a powder product of the above.
[0012]
The phosphate is not particularly limited as long as it is a water-soluble phosphate represented by disodium hydrogen phosphate, sodium phosphate, sodium dihydrogen phosphate, and sodium polyphosphate. Among them, it is most preferable to use disodium hydrogen phosphate.
The iron salt is not particularly limited as long as it is a water-soluble iron salt containing ferrous chloride, ferric chloride, ferrous sulfate, and ferric sulfate, but it is possible to use ferrous sulfate. preferable.
[0013]
When adding the treatment agent for heavy metal-containing contaminated soil (hereinafter also referred to as treatment agent) of the present invention, treating the contaminated soil with water together with the treatment agent increases the contact efficiency between the soil and the treatment agent. It is valid. The kind and compounding ratio of the processing agent to be used are as having described in Claim 1, 3-7 , and it is most preferable to use in the following addition amount ranges.
[0014]
(1) When humic acid and solidifying agent are used together Humic acid and solidifying agent are used in the range of 1/35 to 1/3 by weight. If the blending amount of the solidifying agent is less than this, humic acid may be eluted from the treated soil. Moreover, when the compounding quantity of a solidifying agent becomes more than this, the compounding quantity of humic acid will decrease and the fixing effect of a heavy metal will fall.
(2) When using a mixture of humic acid and silicon dioxide and a solidifying agent, it consists of two components, humic acid and silicon dioxide, and the mixing ratio of humic acid and silicon dioxide is 3/1 to 1/1 by weight. The two-component mixture and the solidifying agent are used in a weight ratio range of 1/35 to 2/1. If it is out of this range, humic acid may be eluted from the treated soil or the effect of immobilizing heavy metals may be reduced.
[0015]
(3) When used in combination humic acid and phosphate salt mixture with a solidifying agent made of two components humic acid and water-soluble phosphate, the compounding ratio of humic acids and water-soluble phosphate is in a weight ratio of 6 / 1-1 / 1 There, the a solidifying agent the two component mixture is used in a range of 1 / 35-2 / 1 by weight. If it is out of this range, humic acid may be eluted from the treated soil or the effect of immobilizing heavy metals may be reduced.
(4) When used in combination humic acid and iron salt and solidifying agent comprises two components of humic acid and water-soluble iron salt, the compounding ratio of humic acids and water-soluble iron salt is in the 6 / 1-1 / 1 in weight ratio Yes , this two-component mixture and solidifying agent are used in a weight ratio in the range of 1/35 to 2/1. If it is out of this range, humic acid may be eluted from the treated soil or the effect of immobilizing heavy metals may be reduced.
(5) When humic acid, silicon dioxide, phosphate mixture and solidifying agent are used in combination, the humic acid, silicon dioxide, and water-soluble phosphate are mixed in three components, and the humic acid content is 5 to 60 parts by weight. The content of these two components is arbitrarily set in the range of 95 to 40 parts by weight. The three component mixture and the solidifying agent are used in a weight ratio of 1/35 to 2/1. If it is out of this range, humic acid may be eluted from the treated soil or the effect of immobilizing heavy metals may be reduced.
(6) When the humic acid, phosphate, iron salt mixture and solidifying agent are used in combination, the humic acid, water-soluble phosphate , and water-soluble iron salt have a three-component composition ratio of humic acid content of 5 to 60 parts by weight, The content of the other two components is arbitrarily set in the range of 95 to 40 parts by weight. The three component mixture and the solidifying agent are used in a weight ratio of 1/35 to 2/1. If it is out of this range, humic acid may be eluted from the treated soil or the effect of immobilizing heavy metals may be reduced.
[0016]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited thereto.
In Examples and Comparative Examples, nitrohumic acid was used as humic acid, and “Nip Seal CX200” (trade name) manufactured by Nippon Silica Kogyo Co., Ltd. was used as silicon dioxide. “Nip seal CX2000” is a powder having a bulk specific gravity of 0.05 (g / ml) or more and a specific surface area of 30 (m 2 / g) or more. In addition, industrial products were used as the solidifying agent and phosphate.
[0017]
Examples 1 to 4
[Comparative Examples 1 and 2]
The soil treatment agent of the present invention was added to and mixed with simulated lead-contaminated soil. The results are shown in Table-1. The mixing ratio of the test procedure and the simulated contaminated soil is as follows.
Contaminated soil composition:
A soil in which the Kanto loam layer and sand were mixed at a weight ratio of 5: 5 was used. The lead content per 1 kg of the mixed soil was 40 mg (adjusted with lead nitrate) and the water content was 27%.
Test procedure:
(1) A predetermined amount of the treatment agent was added to the contaminated soil, mixed well with a glass rod, and left overnight. (2) An elution test was carried out based on the method of Environment Agency Notification No. 46, and the amount of lead elution (mg / L) was determined by atomic absorption spectrophotometry.
[Table 1]
When the treatment agent of the present invention is used, the lead elution amount sufficiently satisfies the lead soil environmental standard value of 0.01 (mg / L) or less, whereas when cement is treated alone. , The value greatly exceeds the reference value, and it can be seen that the present fixing agent has excellent performance.
[0018]
Examples 5 to 6
[Comparative Examples 3 to 4]
The treating agent of the present invention was added to and mixed with simulated cadmium-contaminated soil. The results are shown in Table-2. The simulated contaminated soil composition is as follows. The measurement procedure is the same as in Example 1. Contaminated soil composition:
A soil in which the Kanto loam layer and sand were mixed at a weight ratio of 4: 6 was used. The cadmium content per 1 kg of the mixed soil was 500 mg (adjusted with cadmium nitrate tetrahydrate) and the water content was 27%.
[Table 2]
When the treatment agent of the present invention is used, the cadmium elution amount sufficiently satisfies the cadmium soil environment standard value of 0.01 (mg / L) or less, whereas the treatment with gypsum alone or humic acid When no is used, the value greatly exceeds the reference value, indicating that this immobilizing agent has excellent performance.
[0019]
Examples 7 to 9
[Comparative Examples 5-6]
The treating agent of the present invention was added to and mixed with simulated lead-contaminated soil. The results are shown in Table-3. The simulated contaminated soil formulation is as follows. The measurement procedure is the same as in Example 1.
Contaminated soil composition:
A soil in which the Kanto loam layer and sand were mixed at a weight ratio of 5: 5 was used, the lead content per 1 kg of the mixed soil was 4000 mg (adjusted with lead nitrate), and the water content was 27%.
[Table 3]
When the treatment agent of the present invention is used, the elution amount of lead sufficiently satisfies the soil environmental standard value of 0.01 (mg / L) or less, whereas cement is treated alone or humic. When an acid is not used, it becomes a value which greatly exceeds the reference value, and it can be seen that the present fixing agent has excellent performance.
[0020]
Examples 10-11
[Comparative Examples 7 to 11]
The test result regarding the effect of the heavy metal fixing agent with respect to A city site soil is shown in Table-4. The measurement procedure is the same as in Example 1.
As a comparative example, the test results using the O company liquid chelate product, silicon dioxide alone, silicon dioxide + gypsum solidifying agent, silicon dioxide + cement and cement alone treatment are also shown. In Table 4, “Gypsander” of Ishihara Sangyo Co., Ltd. was used as the gypsum-based solidifying agent.
[0021]
[Table 4]
When the treatment agent of the present invention is used, the total mercury, lead and arsenic elution amounts are 0.0005, 0.01 and 0.01 (mg / L) which are soil mercury reference values for total mercury, lead and arsenic. While sufficiently satisfying the following, when the liquid chelating agent and the cement are treated alone, the value is significantly higher than the reference value, indicating that the present fixing agent has excellent performance.
[0022]
Examples 12 and 13
[Comparative Examples 12 and 13]
Table 5 shows the test results regarding the effect of the heavy metal fixing agent on the T city field soil. The measurement procedure is the same as in Example 1. As a comparative example, the test results of ferrous sulfate alone are also shown.
In Table 5, “Gypsander” of Ishihara Sangyo Co., Ltd. was used as the gypsum-based solidifying agent.
[Table 5]
It can be seen that when the treatment agent of the present invention is used, it is possible to treat the contaminated soil having a large amount of arsenic to a soil environment standard value or less.
Claims (13)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2003152253A JP4233923B2 (en) | 2003-04-18 | 2003-05-29 | Treatment agent for heavy metal contaminated soil and soil treatment method using the same |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2003113720 | 2003-04-18 | ||
JP2003152253A JP4233923B2 (en) | 2003-04-18 | 2003-05-29 | Treatment agent for heavy metal contaminated soil and soil treatment method using the same |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2005000712A JP2005000712A (en) | 2005-01-06 |
JP4233923B2 true JP4233923B2 (en) | 2009-03-04 |
Family
ID=34106240
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2003152253A Expired - Lifetime JP4233923B2 (en) | 2003-04-18 | 2003-05-29 | Treatment agent for heavy metal contaminated soil and soil treatment method using the same |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP4233923B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105344706A (en) * | 2015-12-15 | 2016-02-24 | 四川大学 | Curing agent for lead-contaminated soil remediation and remediation method |
Families Citing this family (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CZ298398B6 (en) * | 2004-04-09 | 2007-09-19 | Ester, Spol. S R. O. | Treatment and exploitation process of contaminated soils |
JP2007330884A (en) * | 2006-06-14 | 2007-12-27 | Hazama Corp | Fluorine insolubilization/stabilization treatment material and treatment method of fluorine contaminated soil or fluorine contaminated ash |
JP2008302333A (en) * | 2007-06-11 | 2008-12-18 | Hitachi Plant Technologies Ltd | Method and apparatus for production of fresh water |
JP4748608B2 (en) * | 2008-03-13 | 2011-08-17 | 独立行政法人国立高等専門学校機構 | Soil-solidifying agent and soil-solidifying method |
JP5448380B2 (en) * | 2008-07-17 | 2014-03-19 | 株式会社大林組 | Arsenic-contaminated soil treatment material |
RU2402511C1 (en) * | 2009-06-15 | 2010-10-27 | Закрытое Акционерное Общество "Твин Трейдинг Компани" | Method of preparing organomineral fertiliser mixture |
CN102379173A (en) * | 2011-08-18 | 2012-03-21 | 中国烟草总公司郑州烟草研究院 | Method for reducing content of cadmium in tobacco leaf produced in soil polluted by cadmium |
JP6286816B2 (en) * | 2011-09-28 | 2018-03-07 | 株式会社大林組 | Manufacturing method for artificial ground block |
CN103242110B (en) * | 2013-05-23 | 2015-03-04 | 四川师范大学 | Method for reducing content of water-soluble fluorine in soil |
JP6326246B2 (en) * | 2014-02-26 | 2018-05-16 | 石坂産業株式会社 | Recycling method of selected soil extracted from earth and sand mixed waste |
JP6296832B2 (en) * | 2014-03-05 | 2018-03-20 | 国立大学法人群馬大学 | Cadmium absorption suppression material and crop cultivation method using the same |
CN104190688B (en) * | 2014-08-01 | 2017-02-22 | 中国科学院生态环境研究中心 | Compound addition material for arsenic-containing waste solidification treatment and preparation method of compound addition material |
CN104624630A (en) * | 2015-01-14 | 2015-05-20 | 中节能六合天融环保科技有限公司 | Passivant for in-situ remediation of polluted farmland and application method of passivant |
CN104945200A (en) * | 2015-07-03 | 2015-09-30 | 刘彬 | Production method of linter pulp soil remediation agent |
CN106967440B (en) * | 2017-04-14 | 2020-09-11 | 东南大学 | Medicament suitable for repairing composite heavy metal polluted soil and production and use methods thereof |
CN108998042B (en) * | 2018-06-22 | 2021-03-09 | 武汉市秀谷科技有限公司 | Soil conditioner for passivating and restoring heavy metal pollution of farmland soil and preparation method thereof |
CN110079328A (en) * | 2018-11-03 | 2019-08-02 | 河南碧海生物科技有限公司 | A kind of soil conditioner reducing soil chloride ion and Heavy Metal Pollution |
CN109294599A (en) * | 2018-11-27 | 2019-02-01 | 宝武集团环境资源科技有限公司 | A kind of passivator for restoration of soil polluted by heavy metal |
CN109609131B (en) * | 2019-01-24 | 2020-06-02 | 中国科学院南京土壤研究所 | Iron-based conditioner for reducing cadmium enrichment of rice and preparation method and application thereof |
CN110144222A (en) * | 2019-04-15 | 2019-08-20 | 中国矿业大学(北京) | A kind of As contaminated soil passivation renovation agent and preparation method thereof |
CN110423624B (en) * | 2019-09-03 | 2021-05-25 | 森特士兴集团股份有限公司 | Soil pollution stabilizing and repairing agent, preparation and application |
CN114085677A (en) * | 2021-12-02 | 2022-02-25 | 南京大学环境规划设计研究院集团股份公司 | Preparation method and application of heavy metal passivation complexing agent |
CN114031362A (en) * | 2021-12-10 | 2022-02-11 | 吉林建筑科技学院 | High humic acid multi-solid waste coupling soft soil curing agent in cold region |
-
2003
- 2003-05-29 JP JP2003152253A patent/JP4233923B2/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105344706A (en) * | 2015-12-15 | 2016-02-24 | 四川大学 | Curing agent for lead-contaminated soil remediation and remediation method |
CN105344706B (en) * | 2015-12-15 | 2018-05-18 | 四川大学 | For the curing agent and restorative procedure of lead-contaminated soil reparation |
Also Published As
Publication number | Publication date |
---|---|
JP2005000712A (en) | 2005-01-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP4233923B2 (en) | Treatment agent for heavy metal contaminated soil and soil treatment method using the same | |
JP4712483B2 (en) | Treatment composition and treatment method for heavy metal contaminated soil | |
KR101801496B1 (en) | Insolubilizing material for specific hazardous substance and method for insolubilizing specific hazardous substance with same | |
CN107418582A (en) | A kind of heavy metals immobilization stabilization agent and application method | |
JP2011136311A (en) | Development of adsorbent-insolubilizer for arsenic and heavy metals using natural zeolite as main raw material, and contaminated-soil reforming method | |
JP5963177B2 (en) | Method for treating solid heavy metal contaminated material and method for producing cement solidified material | |
JP2009256593A (en) | Toxic substance elution reducing material and toxic substance elution reducing treatment method | |
JP3919648B2 (en) | Hazardous heavy metal collector | |
JP3274376B2 (en) | Agglomerating agent for mud, solidifying agent using it | |
JP2003290759A (en) | Heavy metal fixing agent and method for fixing heavy metal | |
JP5437589B2 (en) | Heavy metal insolubilizing agent and soil purification method using the same. | |
JP2007216069A (en) | Treating method of contaminated soil | |
JP4663905B2 (en) | Heavy metal elution inhibitor and heavy metal elution control method for heavy metal contaminated soil | |
JP2007222695A (en) | Harmful metal elution reduction material and elution reduction method for harmful metal using it | |
JP2005131574A (en) | Insolubilization method of heavy metal contaminated soil | |
JP5667376B2 (en) | Treatment agent for contaminated soil and method for treating contaminated soil | |
JP2003290741A (en) | Harmful heavy metal reducing material and harmful heavy metal reducing method using the same | |
JP3676672B2 (en) | Method for modifying contaminated soil and method for modifying sludge | |
JP4493159B2 (en) | Method for manufacturing ground improvement material | |
JP3818446B2 (en) | Heavy metal fixing agent | |
JP7089971B2 (en) | Insolubilization method for heavy metals and insolubilizer | |
JP3942404B2 (en) | Cement admixture | |
JP2012135727A (en) | Method for reducing elution of heavy metal from contaminated soil and composition and kit for reducing elution of heavy metal from contaminated material | |
JPH0268192A (en) | Harmful heavy metal trapping agent for waste water or industrial waste | |
JP5352339B2 (en) | Chemical treatment method for molten fly ash |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20050902 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20070726 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080502 |
|
A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080630 |
|
A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20080819 |
|
A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20081015 |
|
A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20081024 |
|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20081114 |
|
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20081210 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111219 Year of fee payment: 3 |
|
R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 Ref document number: 4233923 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111219 Year of fee payment: 3 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121219 Year of fee payment: 4 |
|
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: 20131219 Year of fee payment: 5 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
EXPY | Cancellation because of completion of term |