JP3977656B2 - How to repair contaminated soil - Google Patents
How to repair contaminated soil Download PDFInfo
- Publication number
- JP3977656B2 JP3977656B2 JP2002040986A JP2002040986A JP3977656B2 JP 3977656 B2 JP3977656 B2 JP 3977656B2 JP 2002040986 A JP2002040986 A JP 2002040986A JP 2002040986 A JP2002040986 A JP 2002040986A JP 3977656 B2 JP3977656 B2 JP 3977656B2
- Authority
- JP
- Japan
- Prior art keywords
- contaminated soil
- soil
- contaminated
- microorganisms
- cleaning
- 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 - Fee Related
Links
- 239000002689 soil Substances 0.000 title claims description 71
- 230000008439 repair process Effects 0.000 title description 4
- 238000000034 method Methods 0.000 claims description 37
- 244000005700 microbiome Species 0.000 claims description 33
- 239000010802 sludge Substances 0.000 claims description 19
- 238000005406 washing Methods 0.000 claims description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 14
- 150000002894 organic compounds Chemical class 0.000 claims description 13
- 235000015097 nutrients Nutrition 0.000 claims description 12
- 238000004140 cleaning Methods 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 10
- 239000002351 wastewater Substances 0.000 claims description 6
- 239000000356 contaminant Substances 0.000 claims description 5
- 239000006227 byproduct Substances 0.000 claims description 4
- 238000004065 wastewater treatment Methods 0.000 claims description 4
- 238000005067 remediation Methods 0.000 claims description 3
- 238000010030 laminating Methods 0.000 claims description 2
- 239000013543 active substance Substances 0.000 claims 1
- 239000003344 environmental pollutant Substances 0.000 description 16
- 231100000719 pollutant Toxicity 0.000 description 16
- 239000000295 fuel oil Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 6
- 241000894006 Bacteria Species 0.000 description 5
- 150000003839 salts Chemical class 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 239000007864 aqueous solution Substances 0.000 description 3
- 238000009412 basement excavation Methods 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 238000005119 centrifugation Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- -1 heavy oil Chemical class 0.000 description 2
- 239000002440 industrial waste Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 239000012190 activator Substances 0.000 description 1
- 239000003570 air Substances 0.000 description 1
- 150000005215 alkyl ethers Chemical class 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 230000001580 bacterial effect Effects 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 230000001143 conditioned effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000012258 culturing Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- VUZPPFZMUPKLLV-UHFFFAOYSA-N methane;hydrate Chemical compound C.O VUZPPFZMUPKLLV-UHFFFAOYSA-N 0.000 description 1
- 230000000813 microbial effect Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 239000003802 soil pollutant Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/10—Biological treatment of water, waste water, or sewage
Landscapes
- Micro-Organisms Or Cultivation Processes Thereof (AREA)
- Biological Treatment Of Waste Water (AREA)
- Processing Of Solid Wastes (AREA)
- Treatment Of Sludge (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、汚染土壌修復を効率よく修復する汚染土壌修復方法に関する。
【０００２】
【従来の技術】
近年、環境汚染問題の解決策として、有機物質等で汚染された土壌の汚染物質を除去し、土壌を修復するための種々の試みがなされており、例えば、汚染された土壌を掘削して表面に露出させ、汚染物質を分解する機能を有する微生物に有用な水や栄養素を注入し、微生物の機能により汚染物質を分解除去するいわゆるオンサイト（ｏｎ−ｓｉｔｅ）法が広く用いられてきた。
オンサイト法による処理においては、土壌を一旦掘削して処理するものであるが、土壌は地上にパイル状に積み上げられ、パイルには窒素、リンなどの微生物にとっての栄養塩、及び空気（Ｏ2）が注入され、元々の土壌に存在していた土着の微生物が増殖し、増殖した微生物により汚染物質が炭酸ガスと水にまで分解されるのである。
【０００３】
特に重油などにより高濃度の有機化合物に汚染された土壌では、そのまま上記のような処理を行うことが困難であり、一旦、土壌を洗浄し、汚染物質を低濃度化してからオンサイト法を行うことが一般的である。
この場合掘削された土壌中には、汚染物質の分解に有用な土着の微生物の数は少なく、さらに、土壌の洗浄工程を経ることで、土壌中の分解微生物は一層少なくなり、菌数でいえば１ｇの土壌中には１００個程度となってしまう。このような土壌に対して、空気、栄養塩等を注入することにより、分解性の微生物を徐々に増殖させ、最大菌数（１０7〜１０8個程度）に達した時点より汚染物質の多くが分解され始めるのである。ところが、実際には分解能を発揮する菌数に達するまでには、一般的に１ヶ月〜２ヶ月の増殖期間が必要であり、土壌の浄化が始まるまでに時間がかかるという欠点があった。
また、オンサイト法の他の態様として、パイル状の土壌中に分解性の微生物を分散させた分散液を直接供給する方法もあるが、分解性の微生物を選択して増殖させ、所定の数に保持し、使用時まで安定的に保存する必要があり、工程が煩雑で、微生物培養或いは保管のための設備を要するため、コストがかかるという問題があった。
【０００４】
【発明が解決しようとする課題】
本発明の目的は、高濃度の有機化合物に汚染された土壌の処理を、微生物を使用して、効率よく短時間で行うことができる汚染土壌修復方法を提供することにある。
【０００５】
【課題を解決するための手段】
本発明の汚染土壌修復方法は、有機化合物により汚染された汚染土壌を掘削し、水又は活性剤を含む水により掘削した汚染土壌を洗浄する洗浄工程と、洗浄に使用された廃水を生物処理法により処理する洗浄廃水処理工程と、該洗浄廃水処理工程において副生された生物汚泥と、洗浄処理された汚染土壌とを混合した混合物を地上に積み上げる積層工程と、該混合物に栄養塩、水、及び空気を注入して混合物内の微生物を増殖させ、微生物の働きにより土壌中の汚染物質を分解する汚染物質分解工程と、を有することを特徴とする。
【０００６】
本発明においては、有機化合物により高濃度汚染された土壌を洗浄する際に排出される廃水の処理に用いた後の残存物である生物汚泥を洗浄後の土壌と混合するため、生物汚泥中に残存する微生物が直ちに土壌中の汚染物質の分解機能を発揮することになり、従来法である、元々の土壌に存在していた土着の微生物の増殖活性化による汚染物質の分解開始までに係る時間を大幅に短縮できる。さらに、従来であれば、それ自体産業廃棄物として処理されるべき生物汚泥を活用しうるため、環境保護性が高く、経済的な土壌修復処理を効率よく行うことができる。
【０００７】
【発明の実施の形態】
以下、本発明を更に詳しく説明する。
本発明においては、高濃度の有機化合物により汚染された汚染土壌はまず掘削により地表へと搬出される。この掘削は公知の方法により行われ、汚染土壌の量、存在位置などにより、例えば、ボーリング装置などの公知の掘削装置を適宜選択して用いて行う。
搬出された汚染土壌は汚染物質の種類や濃度を測定したのち、汚染物質の濃度が所定の値より高い場合、特に、重油などの有機化合物の含有量が５％以上である場合には、洗浄槽に投入して洗浄処理を行う。洗浄は水、あるいは水性溶剤や界面活性剤を所定量含有する水溶液などにより行われる。
【０００８】
汚染土壌中の油分の含有量が多い場合には、例えば、特開平８−３０９３３０号公報や、同８−３１８２９５号公報に記載のような、加熱処理、或いは溶剤処理と加熱とを組み合わせた処理を行って油分の含有量を低減させた後、洗浄処理を行うこともできる。
洗浄処理後、遠心分離などの方法により、洗浄水（廃水）と土壌とを分離する。分離された土壌にはなお、汚染物質が残存しているため、その後、汚染土壌パイルを形成し、微生物による有機化合物の分解処理を行う。この処理については、後述する。
【０００９】
土壌と分離された洗浄水は、高濃度の汚染物質を含有し、そのままでは排水できないため、生物処理法により汚染物質を除去した後、放流する。生物処理法としては、公知の方法を適宜用いることができるが、処理の容易性、効果の観点から生物膜法を適用するのが好ましい。
生物膜法では微生物が膜に固定されているので、攪拌式を用いるにしろ、濾過床式を用いるにしろ、生物汚泥の発生が少ないのが特徴である。ここで発生した生物汚泥は通常、産業廃棄物として処理されるが、有機化合物を分解する特性を有する微生物を高濃度で含有しているため、本発明では、先に洗浄処理した汚染土壌と混合される。
【００１０】
洗浄後の汚染土壌と生物汚泥との混合比（重量比）は、生物汚泥中の活性微生物の数により異なるが、一般的な処理法を行った場合には、汚染土壌１に対して１０-4以上となることが好ましく、１０-3以上となることががさらに好ましい。本発明の方法によれば、ここで用いられる生物汚泥（活性汚泥）は処理中に副生され、上記の有効量は副生された生物汚泥で充足することができるという利点をも有する。汚染土壌と生物汚泥とからなる混合物は、地上にパイル状に積み上げられ、微生物を活性化する空気及び窒素、リンなどの微生物にとっての栄養塩を含有する液体を供給される。空気や栄養塩の供給は、まず、栄養塩水溶液供給装置から栄養塩を含む液体がポンプにより圧送され、コンプレッサーにより供給される空気とともにパイプを経由してパイプ先端より土壌内に噴出されることにより行われる。
この方法によれば、オンサイト法で微生物分散液を供給するよりも低コストで、また、土壌中の微生物を活性化させる数まで増殖させる方法よりも短時間で効果的な汚染土壌の処理を行うことができる。
【００１１】
【実施例】
以下に、実施例を挙げて本発明を具体的に説明するが、本発明はこれに制限されるものではない。
（実施例１）
汚染土壌として、Ａ重油を約５％程度含有するものを処理対象とする。まず、この汚染土壌１トンを、ポリオキシエチレンアルキルエーテル系の生分解性の高い界面活性剤を０．５重量％含有する水溶液で攪拌手段を備えた洗浄槽で洗浄する。洗浄後の汚染土壌の重油の含有量は約１．５％であった。
洗浄水を遠心分離で除去し、分離された洗浄水はＡ重油にて馴養した汚泥を用いた生物膜装置で処理することで清浄化し、排水する。洗浄水を分離することで約２００ｇの生物汚泥（活性汚泥）を得た。次に、前記汚染土壌と生物汚泥とを重量比で５０００：１の割合で混合して混合物を得て、地上に積み上げる。この積層された混合物に対して、ポンプにより栄養塩水溶液が、コンプレッサーにより空気が、それぞれ供給され、これらはパイプを経由してパイプ先端より土壌内に噴出される。この空気と栄養塩により微生物が増殖し、最大菌数（１０7〜１０8個程度）に達した時点より汚染物質の多くが分解され始める。
【００１２】
図１は、混合物中に含有する微生物の増殖状況を経時的に菌体をカウントすることで算出した結果により表示するグラフである。図１のグラフより、本実施例１においては、微生物が汚染物質の多くが分解され始める最大菌数（１０7〜１０8個程度）に達するまでに要する時間が１０日未満であることがわかる。
図２は、本発明の汚染土壌中に含有された汚染物質である重油の残存濃度を示すグラフである。図２のグラフより、本実施例１の方法によれば、重油の残存濃度が周囲に影響を与えないレベルである０．５％になるのに２５日間を要し、その後３０日目で０．３５％程度に減少し、さらに９０日に達するまで処理を継続したが、それ以上の現象は見られなかった。
【００１３】
（比較例１）
前記実施例１と同様の汚染土壌を用い、洗浄処理廃水の生物膜処理で副生された活性汚泥を土壌に混合せず、洗浄後の汚染土壌をパイル状に積み上げて、実施例１におけるとの同様にして、栄養塩と空気とを供給し、土壌中の微生物を増殖させて処理を行った。実施例１におけるのと同様にして、土壌中の菌体数と汚染物質（重油）の残存濃度を測定した。結果を図１、図２のグラフに破線で併記する。
【００１４】
図１のグラフより、比較例１においては、微生物が汚染物質の多くが分解され始める最大菌数（１０7〜１０8個程度）に達するまでに要する時間が２５日であることがわかる。
また、図２のグラフより、比較例１の方法によれば、重油の残存濃度が周囲に影響を与えないレベルである０．５％になるのに５０日以上を要し、その後０．３５％程度に減少したのは９０日後であった。
【００１５】
実施例と比較例の対比により、本発明の如く、廃水処理により副生された微生物を含む生物汚泥を利用することで、汚染土壌の修復が短時間で効率よく進行することがわかる。
【００１６】
【発明の効果】
本発明の汚染土壌修復方法によれば、高濃度の有機化合物に汚染された土壌の処理を、微生物を使用して、効率よく短時間で行うことができる。
【図面の簡単な説明】
【図１】 実施例１及び比較例１の方法における汚染土壌中の微生物の菌体数の変化を示すグラフである。
【図２】 実施例１及び比較例１の方法における汚染土壌中の重油の残存濃度の変化を示すグラフである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a contaminated soil remediation method that efficiently repairs contaminated soil.
[0002]
[Prior art]
In recent years, as a solution to environmental pollution problems, various attempts have been made to remove soil pollutants contaminated with organic substances, etc., and repair the soil. A so-called on-site method has been widely used in which water and nutrients that are useful for microorganisms having a function of decomposing pollutants are injected, and the pollutants are decomposed and removed by the function of the microorganisms.
In the treatment by the on-site method, the soil is once excavated and treated, and the soil is piled up on the ground, and the pile contains nutrients for microorganisms such as nitrogen and phosphorus, and air (O 2). ) Is injected, the native microorganisms that were originally present in the soil grow, and the pollutants are decomposed into carbon dioxide and water by the grown microorganisms.
[0003]
In particular, in soil contaminated with high concentrations of organic compounds such as heavy oil, it is difficult to perform the above treatment as it is, and once the soil is washed to reduce the concentration of contaminants, the on-site method is performed. It is common.
In this case, the excavated soil has a small number of indigenous microorganisms that are useful for decomposing pollutants, and the soil washing process further reduces the number of microorganisms decomposed in the soil. For example, it will be about 100 in 1 g of soil. By injecting air, nutrient salts, etc. into such soil, degradable microorganisms are gradually grown and more pollutants than when the maximum number of bacteria (about 10 7 to 10 8 ) is reached. Will begin to break down. However, in practice, a growth period of 1 to 2 months is generally required to reach the number of bacteria exhibiting resolution, and there is a drawback that it takes time to start soil purification.
As another embodiment of the on-site method, there is a method of directly supplying a dispersion liquid in which degradable microorganisms are dispersed in a pile-like soil. However, a predetermined number of the degradable microorganisms are selected and grown. In other words, the process is complicated and the equipment for culturing or storing microorganisms is required.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for repairing contaminated soil that can efficiently and quickly perform treatment of soil contaminated with high-concentration organic compounds using microorganisms.
[0005]
[Means for Solving the Problems]
The method for repairing contaminated soil according to the present invention includes a cleaning step of excavating contaminated soil contaminated with an organic compound and cleaning the contaminated soil excavated with water containing water or an activator, and a biological treatment method of wastewater used for cleaning. Washing wastewater treatment process treated by the above, a laminating step of stacking a mixture of the mixed sludge and the biological sludge produced as a by-product in the washing wastewater treatment process, and the mixture, nutrient salts, water, And a process for decomposing pollutants in the soil by injecting air to grow microorganisms in the mixture and decomposing pollutants in the soil by the action of the microorganisms.
[0006]
In the present invention, in order to mix the biological sludge, which is a residue after being used for the treatment of wastewater discharged when washing soil highly contaminated with organic compounds, with the washed soil, The remaining microorganisms immediately exert the function of decomposing pollutants in the soil, and the time required until the start of decomposition of pollutants by the activation of indigenous microorganisms that existed in the original soil, which is the conventional method. Can be greatly shortened. Furthermore, conventionally, since biological sludge that should be treated as industrial waste itself can be used, environmental protection is high and economical soil remediation treatment can be performed efficiently.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
In the present invention, contaminated soil contaminated with a high concentration organic compound is first transported to the surface by excavation. This excavation is performed by a known method. For example, a known excavation device such as a boring device is appropriately selected and used depending on the amount of contaminated soil, the location of the soil, and the like.
After removing the contaminated soil, the type and concentration of the pollutant are measured, and if the concentration of the pollutant is higher than a predetermined value, especially if the content of organic compounds such as heavy oil is 5% or more, washing It is put into the tank and washed. Cleaning is performed with water or an aqueous solution containing a predetermined amount of an aqueous solvent or a surfactant.
[0008]
When the content of oil in the contaminated soil is large, for example, as described in JP-A-8-309330 and JP-A-8-318295, a treatment or a combination of solvent treatment and heating. After the oil content has been reduced to reduce the oil content, a washing treatment can also be performed.
After the washing treatment, washing water (waste water) and soil are separated by a method such as centrifugation. Since the pollutants still remain in the separated soil, a contaminated soil pile is formed thereafter, and the organic compound is decomposed by microorganisms. This process will be described later.
[0009]
The wash water separated from the soil contains a high concentration of pollutants and cannot be drained as it is, so it is discharged after removing the pollutants by the biological treatment method. As the biological treatment method, a known method can be appropriately used, but it is preferable to apply the biofilm method from the viewpoint of ease of treatment and effects.
In the biofilm method, since microorganisms are fixed to the membrane, the generation of biological sludge is characterized by using a stirring method or a filtration bed method. The biological sludge generated here is usually treated as industrial waste, but it contains a high concentration of microorganisms that have the property of decomposing organic compounds. Therefore, in the present invention, it is mixed with the contaminated soil previously washed. Is done.
[0010]
The mixing ratio of contaminated soil and the biological sludge after washing (weight ratio) may vary depending on the number of active microorganisms in biological sludge, when performing general processing method, contaminated soil 1 for 10 - It is preferably 4 or more, and more preferably 10 −3 or more. According to the method of the present invention, the biological sludge (activated sludge) used here is produced as a by-product during treatment, and the above-mentioned effective amount can also be satisfied by the produced bio-sludge. A mixture of contaminated soil and biological sludge is piled up on the ground, and supplied with air that activates microorganisms and a liquid containing nutrient salts for microorganisms such as nitrogen and phosphorus. Air and nutrient salts are supplied by first feeding a liquid containing nutrient salts from a nutrient aqueous solution supply device by a pump and ejecting it into the soil from the pipe tip through the pipe together with the air supplied by the compressor. Done.
According to this method, the contaminated soil can be treated more effectively at a lower cost than in the case of supplying a microbial dispersion by the on-site method, and in a shorter time than a method in which the microorganisms in the soil are activated to a number that activates them. It can be carried out.
[0011]
【Example】
Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
Example 1
Contaminated soil containing about 5% A heavy oil is treated. First, 1 ton of this contaminated soil is washed in a washing tank equipped with a stirring means with an aqueous solution containing 0.5% by weight of a polyoxyethylene alkyl ether-based highly biodegradable surfactant. The content of heavy oil in the contaminated soil after washing was about 1.5%.
The washing water is removed by centrifugation, and the separated washing water is cleaned and drained by treating it with a biofilm apparatus using sludge conditioned with heavy oil A. About 200 g of biological sludge (activated sludge) was obtained by separating the washing water. Next, the contaminated soil and the biological sludge are mixed at a weight ratio of 5000: 1 to obtain a mixture and stacked on the ground. The laminated mixture is supplied with an aqueous nutrient salt solution by a pump and air by a compressor, and these are ejected from the pipe tip into the soil via the pipe. Microorganisms grow by this air and nutrients, and many of the pollutants begin to be decomposed when the maximum number of bacteria (about 10 7 to 10 8 ) is reached.
[0012]
FIG. 1 is a graph displaying the growth status of microorganisms contained in a mixture based on the results calculated by counting the cells over time. From the graph of FIG. 1, in the present embodiment 1, the time required to reach the maximum number of bacteria microorganism begins to decompose many contaminants (10 7 to 10 8 or so) is found to be less than 10 days .
FIG. 2 is a graph showing the residual concentration of heavy oil, which is a contaminant contained in the contaminated soil of the present invention. From the graph of FIG. 2, according to the method of Example 1, 25 days were required for the residual concentration of heavy oil to reach 0.5%, which is a level that does not affect the surroundings. It decreased to about 35%, and the treatment was continued until 90 days were reached, but no further phenomenon was observed.
[0013]
(Comparative Example 1)
Using the same contaminated soil as in Example 1 above, the activated sludge produced as a by-product in the biofilm treatment of the cleaning wastewater is not mixed with the soil, and the contaminated soil after cleaning is piled up in a pile. In the same manner as described above, nutrients and air were supplied, and the microorganisms in the soil were propagated for treatment. In the same manner as in Example 1, the number of bacterial cells in the soil and the residual concentration of contaminants (heavy oil) were measured. The results are shown with broken lines in the graphs of FIGS.
[0014]
From the graph of FIG. 1, it can be seen that in Comparative Example 1, it takes 25 days for the microorganisms to reach the maximum number of bacteria (about 10 7 to 10 8 ) at which many of the pollutants start to be decomposed.
From the graph of FIG. 2, according to the method of Comparative Example 1, it takes 50 days or more for the residual concentration of heavy oil to reach 0.5%, which does not affect the surroundings, and thereafter 0.35. It decreased after 90 days when it decreased to about%.
[0015]
By comparing the examples and the comparative examples, it can be seen that, as in the present invention, by using biological sludge containing microorganisms by-produced by wastewater treatment, the repair of contaminated soil proceeds efficiently in a short time.
[0016]
【The invention's effect】
According to the method for repairing contaminated soil of the present invention, treatment of soil contaminated with a high concentration organic compound can be efficiently performed in a short time using microorganisms.
[Brief description of the drawings]
FIG. 1 is a graph showing changes in the number of microorganisms in a contaminated soil in the methods of Example 1 and Comparative Example 1.
FIG. 2 is a graph showing changes in residual concentration of heavy oil in contaminated soil in the methods of Example 1 and Comparative Example 1.
Claims (3)
洗浄に使用された廃水を生物処理法により処理する洗浄廃水処理工程と、
該洗浄廃水の生物処理時に副生された生物汚泥と、洗浄処理された汚染土壌とを混合した混合物を地上に積み上げる積層工程と、
該混合物に栄養塩、水、及び空気を注入して混合物内の微生物を増殖させ、微生物の働きにより土壌中の汚染物質を分解する汚染物質分解工程と、を有する汚染土壌修復方法。A cleaning step of excavating contaminated soil contaminated with an organic compound and cleaning the contaminated soil excavated with water or water containing an active agent;
A cleaning wastewater treatment process for treating the wastewater used for cleaning by a biological treatment method;
A laminating step of stacking a mixture of the biological sludge produced as a by-product during the biological treatment of the washing wastewater and the contaminated soil that has been washed;
A contaminated soil remediation method comprising: injecting nutrients, water, and air into the mixture to grow microorganisms in the mixture and decomposing contaminants in the soil by the action of the microorganisms.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002040986A JP3977656B2 (en) | 2002-02-19 | 2002-02-19 | How to repair contaminated soil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002040986A JP3977656B2 (en) | 2002-02-19 | 2002-02-19 | How to repair contaminated soil |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003236524A JP2003236524A (en) | 2003-08-26 |
| JP3977656B2 true JP3977656B2 (en) | 2007-09-19 |
Family
ID=27781508
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002040986A Expired - Fee Related JP3977656B2 (en) | 2002-02-19 | 2002-02-19 | How to repair contaminated soil |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3977656B2 (en) |
-
2002
- 2002-02-19 JP JP2002040986A patent/JP3977656B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2003236524A (en) | 2003-08-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5631160A (en) | Method for in situ soil remediation | |
| JP5865166B2 (en) | Purification method and apparatus for water containing oils and / or volatile organic compounds | |
| KR101768006B1 (en) | Soil Treatment System Using Nanobubble and Multi-Stage Washing of Inorganic Acid | |
| JP4380020B2 (en) | Ozone treatment method for contaminated soil | |
| Ross | Slurry‐phase bioremediation: Case studies and cost comparisons | |
| JP3977656B2 (en) | How to repair contaminated soil | |
| JP2009039616A (en) | Cleaning accelerator and cleaning method of soil and underground water | |
| US7497948B2 (en) | Method for remediation of soil and groundwater | |
| JP2007253075A (en) | Soil purifying method | |
| JP2879808B2 (en) | How to clean contaminated soil | |
| KR100476134B1 (en) | Remediation method of contaminated soil and groundwater by the sequentially combined treatment of hydrogen peroxide, ultraviolet ray and biological treatment | |
| JP2003010834A (en) | Bioremediation method for polluted soil | |
| JP3221558B2 (en) | Soil purification method and equipment | |
| JP2004025070A (en) | Cleaning method of polluted soil | |
| JP2005262174A (en) | Method for decontaminating contaminated bottom sediment | |
| KR20010105915A (en) | Process for the decontamination of soil containing toxic organic materials and heavy metal | |
| JPH11216457A (en) | Purification of contaminated soil | |
| JP2563010B2 (en) | Method of treating organic chlorine compounds | |
| JPH11179336A (en) | Restoration method and apparatus for oil-contaminated soil | |
| JP2002018400A (en) | Method for decomposing contaminant | |
| EP0671223B1 (en) | Process for the treatment of contaminated sediments | |
| JP2005111461A (en) | Method for cleaning soil contaminated with oil by oil degradation bacterium culture reactor and feeder of rotary nozzle type | |
| JPH09253688A (en) | Method for purifying stratum and ground water polluted with organic chlorine compound | |
| JP2002307051A (en) | Polluted soil cleaning system by biological remediation | |
| JP2000005741A (en) | Original site purifying system of contaminated soil by microorganisms |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20041201 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20060303 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20060322 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20060519 |
|
| 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: 20070619 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20070621 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100629 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 Ref document number: 3977656 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: 20100629 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110629 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110629 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120629 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120629 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130629 Year of fee payment: 6 |
|
| LAPS | Cancellation because of no payment of annual fees |