JP2019188279A - Construction control method, and decontamination method - Google Patents
Construction control method, and decontamination method Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 181
- 238000010276 construction Methods 0.000 title claims abstract description 49
- 238000005202 decontamination Methods 0.000 title abstract 9
- 238000004458 analytical method Methods 0.000 claims abstract description 138
- 239000002689 soil Substances 0.000 claims abstract description 126
- 229910001385 heavy metal Inorganic materials 0.000 claims abstract description 90
- 239000000696 magnetic material Substances 0.000 claims abstract description 28
- 230000000694 effects Effects 0.000 claims abstract description 23
- 238000000746 purification Methods 0.000 claims description 167
- 238000012360 testing method Methods 0.000 claims description 67
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 60
- 238000009430 construction management Methods 0.000 claims description 44
- 238000010828 elution Methods 0.000 claims description 33
- 239000000126 substance Substances 0.000 claims description 24
- 239000002002 slurry Substances 0.000 claims description 16
- 238000010790 dilution Methods 0.000 claims description 10
- 239000012895 dilution Substances 0.000 claims description 10
- 238000012545 processing Methods 0.000 claims description 9
- 238000002441 X-ray diffraction Methods 0.000 claims description 8
- 230000018044 dehydration Effects 0.000 claims description 8
- 238000006297 dehydration reaction Methods 0.000 claims description 8
- 239000011499 joint compound Substances 0.000 claims description 8
- 238000011084 recovery Methods 0.000 claims description 7
- 238000003756 stirring Methods 0.000 claims description 6
- 238000007726 management method Methods 0.000 claims description 5
- 239000007788 liquid Substances 0.000 claims description 4
- 239000010802 sludge Substances 0.000 claims description 4
- 239000010865 sewage Substances 0.000 claims description 3
- 230000003588 decontaminative effect Effects 0.000 abstract 7
- 238000000926 separation method Methods 0.000 abstract 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 76
- 238000007792 addition Methods 0.000 description 16
- 229910052785 arsenic Inorganic materials 0.000 description 16
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 16
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 14
- 229910052753 mercury Inorganic materials 0.000 description 14
- 238000012937 correction Methods 0.000 description 13
- 239000002245 particle Substances 0.000 description 11
- 238000013461 design Methods 0.000 description 10
- 238000009533 lab test Methods 0.000 description 10
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- 230000000052 comparative effect Effects 0.000 description 7
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- 238000012790 confirmation Methods 0.000 description 6
- 238000011109 contamination Methods 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- 238000004140 cleaning Methods 0.000 description 5
- 230000002354 daily effect Effects 0.000 description 5
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- 238000001179 sorption measurement Methods 0.000 description 4
- 238000010979 pH adjustment Methods 0.000 description 3
- 238000010998 test method Methods 0.000 description 3
- 238000007605 air drying Methods 0.000 description 2
- 239000012670 alkaline solution Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000006148 magnetic separator Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000003929 acidic solution Substances 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000009412 basement excavation Methods 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
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- 238000001095 inductively coupled plasma mass spectrometry Methods 0.000 description 1
- 238000004255 ion exchange chromatography Methods 0.000 description 1
- 238000007885 magnetic separation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
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- 239000008213 purified water Substances 0.000 description 1
- 238000005067 remediation Methods 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
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- 238000003950 stripping voltammetry Methods 0.000 description 1
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- 238000004876 x-ray fluorescence Methods 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
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Classifications
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- 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
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/52—Mechanical processing of waste for the recovery of materials, e.g. crushing, shredding, separation or disassembly
Landscapes
- Analysing Materials By The Use Of Radiation (AREA)
- Processing Of Solid Wastes (AREA)
- Treatment Of Sludge (AREA)
- Water Treatment By Sorption (AREA)
Abstract
Description
本発明は、重金属を含有する土壌等の浄化処理を管理するための施工管理方法及びこの施工管理方法を用いた浄化方法に関する。 The present invention relates to a construction management method for managing a purification treatment of soil or the like containing heavy metals, and a purification method using this construction management method.
従来、重金属に汚染された土壌の浄化を、重金属の吸着能を有する鉄粉等の磁性体を用いて行う技術が知られている（例えば、特許文献１〜３参照）。 Conventionally, a technique for purifying soil contaminated with heavy metals using a magnetic material such as iron powder having an ability to adsorb heavy metals is known (for example, see Patent Documents 1 to 3).
特許文献１には、土壌に対して１〜１０質量％の鉄粉と水と重金属の移動を促す薬剤を添加して撹拌し、土壌中の重金属を鉄粉に吸着させ、重金属を担持した鉄粉を磁選機によって土壌から分離する浄化方法が開示されている。特許文献２には、シールド工法で発生した掘削土に、鉄粉等の吸着剤を添加し、重金属を掘削土から分離する浄化方法及びシステムが開示されている。特許文献３には、１回の利用で鉄粉を廃棄する場合に比べてコストの低減を図る目的で、磁力選別にて土壌から回収した鉄粉を、再度重金属を含む土壌に返送して、鉄粉を再使用する浄化方法及びシステムが開示されている。 In Patent Document 1, 1 to 10% by mass of iron powder and an agent that promotes the movement of water and heavy metals are added to the soil and stirred to adsorb the heavy metals in the soil to the iron powder, thereby supporting heavy metals. A purification method for separating powder from soil by a magnetic separator is disclosed. Patent Document 2 discloses a purification method and system in which an adsorbent such as iron powder is added to excavated soil generated by the shield method to separate heavy metals from the excavated soil. In Patent Document 3, the iron powder collected from the soil by magnetic sorting is returned to the soil containing heavy metal again for the purpose of reducing the cost compared to the case of discarding the iron powder in one use, A purification method and system for reusing iron powder is disclosed.
また、浄化の効果確認には、環境省が定める公定分析法が用いられている。この公定分析法では、浄化対象の土壌のサンプルを２〜３日風乾し、１０倍希釈して６時間振とうした後、ＩＣＰ／ＭＳ分析法により重金属の量を測定しているため、分析処理の結果が得られるまでに数日間を要している。 The official analysis method established by the Ministry of the Environment is used to confirm the purification effect. In this official analysis method, the soil sample to be purified is air-dried for 2 to 3 days, diluted 10 times and shaken for 6 hours, and then the amount of heavy metal is measured by ICP / MS analysis method. It takes several days to get the result.
ここで、土壌等の浄化に使用する鉄粉の添加量や処理時間等、浄化の施工計画は、土壌等の事前分析によって決定している。しかし、実際に現地で浄化作業を行う際の土壌等の汚染濃度や土質条件が、事前分析に用いたサンプルの汚染濃度や土質条件とは異なる場合がある。そのため、浄化の効率化やコストを考えると、鉄粉の使用量等を土壌等の状態に応じて適切に調整できることが望ましい。また、鉄粉を繰り返し使用すると、吸着能力がなくなる「破過」という現象が起こる。この破過が起こる時期（タイミング）も、土壌等の状態に応じて変化する場合があるため、破過の時期についても現地で管理できることが望ましい。このように、鉄粉の使用量、処理時間、破過のタイミングなどの施工管理の調整を、現地で簡易に行うことができる技術の開発が望まれている。 Here, the construction plan for the purification, such as the amount of iron powder used for the purification of the soil and the processing time, is determined by prior analysis of the soil and the like. However, there are cases where the contamination concentration and soil conditions of soil and the like when actually performing the purification work on site are different from the contamination concentration and soil conditions of the sample used for the preliminary analysis. For this reason, considering the efficiency and cost of purification, it is desirable that the amount of iron powder used can be appropriately adjusted according to the state of the soil and the like. Moreover, when iron powder is repeatedly used, a phenomenon called “breakthrough” occurs in which the adsorption capacity is lost. Since the timing (timing) at which this breakthrough occurs may change depending on the state of the soil or the like, it is desirable that the breakthrough timing can be managed locally. As described above, it is desired to develop a technique capable of easily performing on-site adjustment of construction management such as the amount of iron powder used, processing time, and timing of breakthrough.
本発明は、上記の事情に鑑みて為されたもので、重金属を含有する土壌等の浄化処理を効率的に行うための施工管理を、現地で容易に行うことを目的としている。 This invention is made | formed in view of said situation, and it aims at performing construction management for performing the purification process of the soil etc. which contain heavy metal efficiently on-site easily.
前記目的を達成するために、本発明の施工管理方法は予め決められた施工条件に従って、重金属を含有する浄化対象に磁性体を添加し、前記重金属を吸着した前記磁性体を所定の選別法により回収することで、前記浄化対象から前記重金属を除去する浄化処理を、管理するための施工管理方法であって、前記浄化対象から採取したサンプルから溶出される前記重金属を迅速分析法によりオンサイトの試験室内で分析する現地分析工程と、前記現地分析工程での分析結果に基づいて、前記浄化対象の浄化効果を確認し、前記施工条件の調整を行う運転管理工程と、を有することを特徴とする。 In order to achieve the above object, according to the construction management method of the present invention, a magnetic material is added to a purification target containing heavy metal according to a predetermined construction condition, and the magnetic material adsorbing the heavy metal is subjected to a predetermined sorting method. A construction management method for managing a purification process for removing the heavy metal from the purification target by collecting the heavy metal eluted from the sample collected from the purification target by an on-site analysis method. A field analysis process for analyzing in a test room, and an operation management process for confirming the purification effect of the purification target and adjusting the construction conditions based on the analysis result in the field analysis process, To do.
ここで、前記施工条件が、前記浄化対象への前記磁性体の添加量、前記磁性体の繰り返しの使用回数、及び前記磁性体による前記浄化対象の処理時間の少なくともいずれか１つを含むものとすることができる。また、前記サンプルが、前記重金属を含有する前記浄化対象としての土壌、汚泥、汚水及び泥水のいずれかから採取した浄化前サンプル、及び前記浄化対象を所定の浄化法で浄化した浄化後サンプルのいずれかであり、前記現地分析工程では、前記浄化前サンプルに対しては、オンサイトの前記試験室内で前記磁性体を添加して浄化し、前記磁性体を回収した後に迅速分析法によって分析し、前記浄化後サンプルに対しては、直接に迅速分析法によって分析するものとすることができる。 Here, the construction conditions include at least one of the addition amount of the magnetic material to the purification target, the number of times the magnetic material is repeatedly used, and the processing time of the purification target by the magnetic material. Can do. Further, any of the pre-purification sample collected from any of soil, sludge, sewage and mud water as the purification target containing the heavy metal, and the post-purification sample obtained by purifying the purification target by a predetermined purification method. In the on-site analysis step, the sample before purification is purified by adding the magnetic substance in the on-site test chamber, and the magnetic substance is collected and analyzed by a rapid analysis method. The sample after purification can be directly analyzed by a rapid analysis method.
さらに、前記現地分析工程では、前記サンプルを所定の希釈状態となるように水で希釈し、所定時間の振とう後に、蛍光Ｘ線分析により前記サンプル中の前記重金属の溶出量を測定するものとすることができる。また、前記現地分析工程は、前記サンプルとの固液比が１：１〜１：２０となるように水を加えて前記サンプルをスラリー化してスラリーを得る第一工程と、前記スラリーに前記磁性体を添加して撹拌する第二工程と、前記磁性体が添加された前記スラリーに磁石体を直接に接触させて前記磁性体を回収する第三工程と、前記磁性体の回収後の前記スラリーを脱水する第四工程と、脱水後の前記サンプル中の前記重金属を迅速分析法によって分析する第五工程と、を有するものとすることができる。 Further, in the on-site analysis step, the sample is diluted with water so as to be in a predetermined dilution state, and after shaking for a predetermined time, the elution amount of the heavy metal in the sample is measured by fluorescent X-ray analysis; can do. The on-site analysis step includes a first step of obtaining a slurry by adding water so that a solid-liquid ratio with the sample is 1: 1 to 1:20 and obtaining a slurry, and the magnetic to the slurry. A second step of adding and stirring the body, a third step of bringing the magnet body into direct contact with the slurry to which the magnetic body has been added and collecting the magnetic body, and the slurry after the recovery of the magnetic body And a fifth step of analyzing the heavy metal in the sample after dehydration by a rapid analysis method.
また、本発明の浄化方法は、予め決められた施工条件に従って、重金属を含有する浄化対象に磁性体を添加し、前記重金属を吸着した前記磁性体を所定の選別法により回収することで、前記浄化対象から前記重金属を除去する浄化処理であって、上述のような施工管理方法により、前記施工条件を調整する工程を有することを特徴とする。 In addition, the purification method of the present invention adds a magnetic material to a purification object containing heavy metal according to a predetermined construction condition, and recovers the magnetic material adsorbing the heavy metal by a predetermined sorting method, A purification process for removing the heavy metal from the purification target, characterized by having a step of adjusting the construction conditions by the construction management method as described above.
このように構成された本発明によれば、現地で採取した浄化対象のサンプルから溶出される重金属を、現地の室内試験での迅速分析によって迅速かつ精度よく分析することができる。この分析結果に基づいて、浄化効果の確認を簡易に行うことができるとともに、浄化処理の施工条件を土壌等の状態に応じて適切に調整することができる。したがって、重金属を含有する土壌等の浄化処理を効率的に行うための施工管理を、現地で容易に行うことができる。 According to the present invention configured as described above, heavy metals eluted from a sample to be purified collected on-site can be analyzed quickly and accurately by a rapid analysis in an on-site laboratory test. Based on the analysis result, the purification effect can be easily confirmed, and the construction conditions for the purification treatment can be appropriately adjusted according to the state of the soil and the like. Therefore, construction management for efficiently purifying the soil containing heavy metals can be easily performed locally.
以下、本発明の一実施形態に係る浄化処理の施工管理方法を用いた浄化方法について、図面を参照しながら説明する。本実施形態の浄化方法は、重金属を含有する浄化対象に磁性体を添加し、その後に磁性体を回収することで、浄化対象から重金属を除去して浄化する方法である。また、この浄化方法で用いられる施工管理方法は、浄化対象から採取した所定のサンプル中の重金属をオンサイトで迅速分析によって分析し、浄化対象の浄化が適切に行われたか否か等を簡易に確認するとともに、分析結果に応じて浄化処理の施工条件を調整することで、浄化処理が効率的かつコスト性よく行えるように管理する方法である。 Hereinafter, a purification method using a purification processing construction management method according to an embodiment of the present invention will be described with reference to the drawings. The purification method of this embodiment is a method of removing and purifying heavy metal from the purification target by adding a magnetic substance to the purification target containing heavy metal and then collecting the magnetic substance. In addition, the construction management method used in this purification method is to analyze the heavy metal in a predetermined sample collected from the purification target by on-site rapid analysis, and to easily determine whether or not the purification target has been properly purified. It is a method of managing so that the purification process can be performed efficiently and cost-effectively by confirming and adjusting the construction condition of the purification process according to the analysis result.
本明細書でいう「重金属を含有する浄化対象」とは、「重金属を含有する浄化対象」は勿論、「重金属を溶出する浄化対象」、さらには「重金属を含有し、かつ溶出する浄化対象」も含む意味で用いている。本明細書では、特に断りのない場合は「含有」は、「含有」若しくは「溶出」、又は「含有及び溶出」を意味するものとする。 The “purification object containing heavy metal” as used herein means “purification object that elutes heavy metal” as well as “purification object that elutes heavy metal”, and further “purification object that contains and dissolves heavy metal” Is also used to mean. In this specification, unless otherwise specified, “containing” means “containing” or “elution”, or “containing and eluted”.
重金属を含有する浄化対象としては、例えば、重金属を含有する土壌、汚泥、水、泥水などが挙げられ、これらの浄化に本実施形態の施工管理方法と浄化方法を好適に適用することができる。なお、本実施形態では、浄化対象として重金属を含有し、溶出する土壌を浄化する際の施工管理方法と浄化方法について主に説明する。 Examples of the purification target containing heavy metals include soil, sludge, water, mud water and the like containing heavy metals, and the construction management method and purification method of this embodiment can be suitably applied to these purifications. In the present embodiment, a construction management method and a purification method for purifying soil that contains heavy metal as a purification target and elutes will be mainly described.
重金属としては、砒素、水銀、鉛、カドミウム、六価クロム、セレン、アンチモン、銅、亜鉛などが挙げられる。磁性体としては、鉄粉や、鉄を含む粒子等が好適に挙げられるが、これらに限定されるものではなく、重金属の吸着能を有し、土壌から回収可能であればよい。これらの磁性体の中でも、鉄粉が最も好適に挙げられ、上記のような重金属を含有する土壌等から、重金属を効率的に除去することができる。 Examples of heavy metals include arsenic, mercury, lead, cadmium, hexavalent chromium, selenium, antimony, copper, and zinc. Suitable examples of the magnetic material include iron powder and iron-containing particles, but the magnetic material is not limited to these, and any magnetic material may be used as long as it has an ability to adsorb heavy metals and can be recovered from soil. Among these magnetic materials, iron powder is most preferably mentioned, and heavy metals can be efficiently removed from the soil containing heavy metals as described above.
また、施工管理方法で用いる「浄化対象から採取したサンプル」は、いわゆる「浄化対象由来のサンプル」であり、浄化前の浄化対象から採取したサンプル、浄化後の浄化対象から採取したサンプルも含む意味である。より具体的には、浄化対象の土壌等そのものから採取したサンプルや、浄化対象の土壌等から採取したサンプルに対して、オンサイトで磁性体を添加して浄化し、磁性体を回収した後のサンプルが挙げられる。また、浄化装置を用いて適宜の浄化方法により浄化した後の土壌等から採取したサンプルが挙げられるが、これらに限定されるものではない。 The “sample collected from the purification target” used in the construction management method is a so-called “sample derived from the purification target” and includes a sample collected from the purification target before purification and a sample collected from the purification target after purification. It is. More specifically, a sample collected from the soil to be purified itself, or a sample collected from the soil to be purified, etc., after adding a magnetic substance and purifying it after collecting the magnetic substance A sample is given. Moreover, although the sample extract | collected from the soil etc. after having refine | purified with the suitable purification method using the purification apparatus is mentioned, It is not limited to these.
本実施形態の浄化方法を実行するための浄化システムは、事前室内試験を行うために分析センターや工場等の事前試験室内に設けられた事前試験装置と、施工管理のための現地試験を行う現地（オンサイト）の現地試験室内に設けられた現地試験装置、及び実際に浄化処理を行う浄化装置（浄化プラント）と、を備えて構成される。 The purification system for carrying out the purification method of the present embodiment includes a pre-test apparatus provided in a pre-test room such as an analysis center or a factory for performing a pre-in-house test, and a site for conducting a field test for construction management. It is configured to include a field test apparatus provided in a field test room (on-site) and a purification apparatus (purification plant) that actually performs a purification process.
事前室内試験のための事前試験装置と、現地試験のための現地試験装置とは、同等のものを用いることができる。例えば、土壌を解砕するためのハンマーや簡易な解砕機等の解砕手段、スラリー化や攪拌のための卓上ボールミル装置、磁性体を回収するための磁石棒等の簡易な回収具、吸引ろ過器等の簡易な脱水装置、蛍光Ｘ線分析機、各種容器や器具などが挙げられる。 The same thing can be used for the prior test apparatus for a prior laboratory test, and the local test apparatus for a field test. For example, a crushing means such as a hammer or a simple crusher for crushing soil, a desktop ball mill device for slurrying or stirring, a simple collection tool such as a magnet bar for collecting magnetic material, suction filtration Simple dehydrator such as a vacuum vessel, fluorescent X-ray analyzer, various containers and instruments.
浄化装置は、従来公知の何れのものを用いてもよく、特に限定されないが、例えば、解砕機、分級装置、ｐＨ調整槽、鉄粉混合槽、鉄粉回収装置、脱水機、水や土壌の供給手段、配管などを備えて構成される（図３参照）。 Any known purification device may be used, and is not particularly limited. For example, a crusher, a classification device, a pH adjustment tank, an iron powder mixing tank, an iron powder recovery device, a dehydrator, water and soil A supply means, piping and the like are provided (see FIG. 3).
以下、上記浄化システムで実行される本実施形態の施工管理方法及び浄化方法について、図１〜図３のフローチャート及び図４の概略図を参照しながら説明する。 Hereinafter, the construction management method and the purification method of the present embodiment executed in the purification system will be described with reference to the flowcharts of FIGS. 1 to 3 and the schematic diagram of FIG. 4.
図１のフローチャートに示すように、本実施形態に係る浄化方法は、土質試験工程（ステップＳ１）と、公定分析工程（ステップＳ２）と、浄化処理適用の可否の判定公定（ステップＳ３）と、事前室内試験工程（ステップＳ４）と、設計・計画工程（ステップＳ５）と、本施工工程（ステップＳ６）と、を有している。 As shown in the flowchart of FIG. 1, the purification method according to the present embodiment includes a soil test process (step S1), an official analysis process (step S2), and a determination official decision (step S3) on whether or not the purification process can be applied. It has a preliminary indoor test process (step S4), a design / planning process (step S5), and a main construction process (step S6).
ステップＳ１の土質試験工程では、浄化対象から採取したサンプルに対して、粒度試験、ｐＨ測定等の土質試験を行って、粒度組成、ｐＨ等の土質条件を取得する。この土質試験工程と並行して、ステップＳ２の公定分析工程を行って、サンプルに対する公定分析を行う。公定分析は、計量証明事業登録されている分析機関で、公定分析法（平成３年環境庁告示第４６号）に基づいて行われる。 In the soil test process in step S1, soil samples such as a particle size test and pH measurement are performed on the sample collected from the purification target, and soil conditions such as particle size composition and pH are acquired. In parallel with this soil test process, the official analysis process of step S2 is performed to perform official analysis on the sample. The official analysis is conducted by an analysis organization registered in the metrology certification business based on the official analysis method (Environmental Agency Notification No. 46 of 1991).
図２紙面左側のフローチャートに従って分析機関で行われる公定分析の流れの概略を説明する。浄化対象の土壌からサンプルを採取し（ステップＳ１１）、このサンプルに対して２〜３日間の風乾を行う（ステップＳ１２）。次に、風乾を行ったサンプルに水を加えて１０倍希釈し、振とう装置を用いて６時間振とうする（ステップＳ１３）。振とうが終わったら、分析装置（例えば、ＩＣＰ／ＭＳ、イオンクロマトグラフィー、原子吸光等）によって、サンプル中に含有される重金属を分析し、その含有量や溶出量（濃度）を測定する（ステップＳ１４）。公定分析法では、分析開始から数日後に分析結果が得られる。 An outline of the flow of the official analysis performed in the analysis organization will be described according to the flowchart on the left side of FIG. A sample is collected from the soil to be purified (step S11), and the sample is air-dried for 2 to 3 days (step S12). Next, water is added to the air-dried sample to dilute it 10 times, and shaken for 6 hours using a shaker (step S13). When the shaking is finished, the heavy metal contained in the sample is analyzed by an analyzer (for example, ICP / MS, ion chromatography, atomic absorption, etc.), and the content and elution amount (concentration) are measured (step) S14). In the official analysis method, analysis results are obtained several days after the start of analysis.
次に、ステップＳ１で取得した土質条件や、ステップＳ２で分析機関から報告される分析結果に基づいて、浄化処理が適用可能な土壌か否か判断する（ステップＳ３）。例えば、土壌汚染対策法で定められている重金属の基準値に基づいて、浄化の必要がある土壌か否か、磁性体による浄化が可能であるか否かなどを判断する。 Next, based on the soil condition acquired in step S1 and the analysis result reported from the analysis organization in step S2, it is determined whether the soil is applicable to the purification process (step S3). For example, based on the reference value of heavy metals defined by the Soil Contamination Countermeasures Law, it is determined whether or not the soil needs to be cleaned, whether or not it can be cleaned with a magnetic material.
浄化処理の適用が可能と判断した場合は（ＹＥＳ）、次のステップＳ４の事前室内試験工程に進む。これに対して、浄化処理の適用外と判断した場合は（ＮＯ）、浄化は不可として、その後のステップＳ４〜Ｓ６の工程をスキップし、終了する。 If it is determined that the purification process can be applied (YES), the process proceeds to the next indoor test process in step S4. On the other hand, if it is determined that the purification process is not applicable (NO), the purification is not possible, and the subsequent steps S4 to S6 are skipped and the process ends.
ステップＳ４の事前室内試験工程の処理の流れを、図２紙面右側のフローチャートに従って説明する。まず、事前試験室内にて、土壌のサンプルの室内試験と迅速分析を行う（ステップＳ２１）。この室内試験と迅速分析の各工程は、現地試験室内と同等の事前試験装置と迅速分析法を用いて、後述の現地分析工程の現地室内試験工程（ステップＳ４０）と迅速分析工程（ステップＳ５０）と同様の手順で行う。そのため、ここでは詳細な説明は省略する。 The flow of the preliminary indoor test process in step S4 will be described with reference to the flowchart on the right side of FIG. First, a laboratory test and quick analysis of a soil sample are performed in a pre-test room (step S21). Each process of the laboratory test and the rapid analysis is performed by using a pre-test apparatus and a rapid analysis method equivalent to those of the local laboratory, a local laboratory test process (step S40) and a rapid analysis process (step S50) of the local analysis process described later. Follow the same procedure. Therefore, detailed description is omitted here.
次に、迅速分析後のサンプルに対して粒度試験等の土質試験を行って、粒度組成、ｐＨ等の土質条件を取得する（ステップＳ２２）。これと並行して、迅速分析後のサンプルに対して分析機関での公定分析を行い（ステップＳ２３）、この公定分析の結果に基づいて、迅速分析の検証を行う。また、迅速分析の結果、公定分析の結果及び土質条件に基づいて、鉄粉洗浄の条件（添加量、処理時間など）、浄化処理を管理するための公定分析法と迅速分析法の相関、及び鉄粉の破過時期など、浄化処理の設計・計画のための基礎データを取得する（ステップＳ２４）。 Next, a soil test such as a particle size test is performed on the sample after the rapid analysis to acquire soil conditions such as a particle size composition and pH (step S22). In parallel with this, the official analysis at the analysis organization is performed on the sample after the quick analysis (step S23), and the quick analysis is verified based on the result of the official analysis. In addition, based on the results of rapid analysis, official analysis results and soil conditions, iron powder washing conditions (addition amount, treatment time, etc.), correlation between official analysis method and rapid analysis method for managing purification treatment, and Basic data for design / planning of the purification process such as the breakthrough time of the iron powder is acquired (step S24).
次のステップＳ５の設計・計画工程では、ステップＳ１の土質試験工程で取得した土質条件、ステップＳ２の公定分析工程での公定分析結果、ステップＳ４で取得した基準データに基づいて、実際の環境（実プラント）での土壌の浄化処理手順の設計と計画を行う。具体的には、土壌中の重金属の種類、含有量や溶出量及び事前室内試験の結果に基づいて、好適な鉄粉の添加量や処理時間などを決定する。鉄粉の添加量は、特に限定されないが、添加量が少なすぎると重金属の吸着が十分に行えなくなり、添加量が多すぎると無駄が生じてコスト高となるため好ましくない。例えば、土壌に対して１〜２０重量％とすることが好ましく、１〜１０％とすることがより好ましい。添加量をこの範囲内で設定することで、重金属の吸着能に優れ、しかも無駄のない使用が可能となり、コストを低減することができる。 In the next design / planning process of step S5, the actual environment (based on the soil conditions acquired in the soil test process of step S1, the official analysis result in the official analysis process of step S2, and the reference data acquired in step S4) Design and plan soil remediation procedures in actual plant. Specifically, a suitable iron powder addition amount, treatment time, and the like are determined based on the type, content and elution amount of heavy metal in the soil, and the results of a prior laboratory test. The addition amount of the iron powder is not particularly limited. However, if the addition amount is too small, the heavy metal cannot be sufficiently adsorbed, and if the addition amount is too large, waste is generated and the cost is increased. For example, it is preferable to set it as 1-20 weight% with respect to soil, and it is more preferable to set it as 1-10%. By setting the addition amount within this range, it is possible to use the metal with excellent heavy metal adsorption capacity without waste, and to reduce the cost.
また、このステップＳ５では、公定分析法と迅速分析法の相関に基づいて、現地で行う迅速分析の検証を行うとともに、迅速分析でのサンプルの好適な処理条件（例えば、希釈率、分析結果の含水率補正の方法、振とう時間、振とう方法等）や、公定分析と、迅速分析による現地分析工程のそれぞれの実行タイミングなどを決定する。 Further, in this step S5, on the basis of the correlation between the official analysis method and the rapid analysis method, verification of the rapid analysis performed locally is performed, and suitable processing conditions (for example, dilution rate, analysis result) of the sample in the rapid analysis are performed. Moisture content correction method, shaking time, shaking method, etc.), official analysis and execution timing of each field analysis process by rapid analysis.
公定分析法では、固体に対し１０倍（重量）の水量で溶出することが決められているため、これに対応させて、本実施形態の現地分析工程での土壌の希釈率を１０倍とした。また、含水率補正の方法としては、事前含水率補正と試験後含水率補正とが挙げられる。事前含水率補正を用いた際の分析手順としては、例えば、サンプルが土壌等の固体の場合、振とう前にサンプルの含水量を電子レンジ法で迅速に測定し、測定結果に基づいてサンプルに水を加えて、希釈率が１０倍になるように調整する。その後、サンプルを振とうし、蛍光Ｘ線分析により迅速分析する。 In the official analysis method, it is determined that the amount of water to be eluted is 10 times (weight) with respect to the solid, and accordingly, the soil dilution rate in the field analysis process of the present embodiment is 10 times corresponding to this. . In addition, examples of the moisture content correction method include pre-water content correction and post-test moisture content correction. For example, if the sample is a solid such as soil, the moisture content of the sample is quickly measured by a microwave method before shaking, and the sample is converted into a sample based on the measurement result. Add water and adjust the dilution ratio to 10 times. Thereafter, the sample is shaken and rapidly analyzed by X-ray fluorescence analysis.
また、試験後含水率補正を用いた際の分析手順としては、例えば、振とう前に、湿潤状態でサンプルに１０倍量の水を加えた後、振とうして迅速分析する。この作業と並行して、電子レンジ法にてサンプルの含水量を測定し、迅速分析での分析結果を含水量で補正する。なお、サンプルが泥水状の場合は、そのまま迅速分析するか、又は泥水の比重を測定して、１０倍量になるよう水を加えて調整した後、迅速分析する。また、サンプルが水の場合は、希釈等せずにそのまま迅速分析する。 Moreover, as an analysis procedure at the time of using the moisture content correction after the test, for example, before shaking, a 10-fold amount of water is added to the sample in a wet state, and then shaken to quickly analyze. In parallel with this work, the moisture content of the sample is measured by the microwave oven method, and the analysis result in the rapid analysis is corrected with the moisture content. In addition, when a sample is a muddy water state, it analyzes quickly as it is, or measures the specific gravity of muddy water, adjusts it by adding water so that it may become 10 times amount, and then analyzes quickly. When the sample is water, the sample is quickly analyzed without dilution.
サンプルの振とう時間は、サンプルと水との混合状態が平衡状態となればよく、１０分以内が好ましく、５分以内がより好ましく、５分程度が最も好ましい。振とう方法としては、超音波振とうや一般的な振とう器を用いた振とう（以下、「通常振とう」という）などが挙げられるが、より簡易であることから通常振とうが好適に挙げられる。このような振とう時間及び振とう方法によって土壌と水とを混合することで、簡易かつ迅速に平衡状態とすることができる。また、鉄粉の破過時期に基づいて、鉄粉の繰り返し使用の際の使用回数を決定する。 The sample shaking time is sufficient if the mixed state of the sample and water is in an equilibrium state, preferably within 10 minutes, more preferably within 5 minutes, and most preferably about 5 minutes. Examples of the shaking method include ultrasonic shaking and shaking using a general shaker (hereinafter referred to as “normal shaking”). However, normal shaking is preferable because it is simpler. It is done. By mixing soil and water by such a shaking time and shaking method, an equilibrium state can be achieved easily and quickly. Moreover, based on the breakthrough time of the iron powder, the number of times of use when the iron powder is repeatedly used is determined.
上記のようにステップＳ５で決定した設計・計画に基づいて、現地（オンサイト）での土壌の浄化処理の本施工工程を実行する（ステップＳ６）。この本施工工程中の浄化の効果確認は、公定分析と迅速分析にて行う。日々の効果確認や、施工条件の調整等による施工管理は、迅速分析結果に基づいて行う。以下、ステップＳ６の本施工工程の詳細について、図３のフローチャート及び図４の概略図を参照しながら説明する。 Based on the design / plan determined in step S5 as described above, the actual construction process of the soil purification process at the site (on-site) is executed (step S6). The effect of purification during this construction process is confirmed by official analysis and quick analysis. Construction management by checking daily effects and adjusting construction conditions is performed based on the results of quick analysis. Hereinafter, the details of the main construction process in step S6 will be described with reference to the flowchart of FIG. 3 and the schematic diagram of FIG.
図３に示すように、本施工工程は、現地（オンサイト）で行われ、浄化装置を用いて土壌の浄化を行う浄化処理工程（ステップＳ３０）と、現地で土壌中の重金属を分析する現地分析工程（ステップＳ４０及びＳ５０）と、現地分析工程での分析結果に基づいて浄化処理工程を管理する運転管理工程（ステップＳ６０）と、を有している。以下では、浄化処理前の、重金属によって汚染された土壌を「汚染土壌」ということがあり、浄化処理後の土壌を「浄化土壌」又は「浄化土」ということがあり、浄化後に土壌から分離された水分を「浄化水」又は「ろ水」ということがある。 As shown in FIG. 3, this construction process is performed on site (on-site), and a purification process (step S30) that purifies the soil using a purification device, and a site where heavy metals in the soil are analyzed locally. It has an analysis process (steps S40 and S50) and an operation management process (step S60) for managing the purification treatment process based on the analysis result in the field analysis process. In the following, soil contaminated with heavy metals before purification treatment is sometimes referred to as “contaminated soil”, and soil after purification treatment is sometimes referred to as “purified soil” or “purified soil”. The water is sometimes referred to as “purified water” or “filtered water”.
ステップＳ３０の浄化工程は、設計・計画工程で設定された施工条件（施工条件が調整された場合は調整後の施工条件）に従って、浄化装置によって汚染土壌の浄化を実際に行う工程である。図３に示すように、掘削し運搬した後の汚染土壌から異物を除去した後、汚染土壌と水を土壌解砕機に投入して、解砕を行う（ステップＳ３１）。次に、解砕物に対して分級装置によって分級を行う（ステップＳ３２）。この分級では、例えば、粒径２ｍｍ以下と、２ｍｍ超のものに分級する。粒径２ｍｍ超の土壌に関しては、現地室内試験で分析した上で浄化済みとして処理することができる。 The purification process of step S30 is a process of actually purifying the contaminated soil by the purification device according to the construction conditions set in the design / planning process (the construction conditions after adjustment when the construction conditions are adjusted). As shown in FIG. 3, after removing foreign substances from the contaminated soil after being excavated and transported, the contaminated soil and water are put into a soil crusher and crushed (step S31). Next, classification is performed on the crushed material by a classification device (step S32). In this classification, for example, the particle size is 2 mm or less and more than 2 mm. Soil having a particle size of more than 2 mm can be treated as having been purified after being analyzed by an on-site laboratory test.
次に、粒径２ｍｍ以下の土壌（細粒分）をｐＨ調整槽に移送し、汚染土壌のｐＨに応じて酸性溶液又はアルカリ性溶液を適宜注入し、汚染土壌のｐＨを、例えば６〜８の中性域に調整する（ステップＳ３３）。ｐＨ調整後の汚染土壌を鉄粉混合槽に移送し、鉄粉を添加して混合することで、汚染土壌中の重金属を鉄粉に付着させる（ステップＳ３４）。このとき、設計・計画工程にて予め設定された添加量（施工管理によって添加量が調整された場合は、調整後の添加量）に基づいて鉄粉が添加される。次に、鉄粉が混入した土壌を、鉄粉回収装置に移送し、土壌中から鉄粉を回収する（ステップＳ３５）。鉄粉の回収の方法は、特に限定されることはなく、例えば、磁選機等を用いて磁力によって選別する磁力選別、重力選別機等を用いた重力選別、篩等を用いた篩選別のいずれかの選別法、又はこれらを複数組み合わせた選別法などが挙げられる。この中でも、磁力選別を用いた回収方法が好適であり、効率的な回収が可能である。 Next, the soil having a particle size of 2 mm or less (fine particles) is transferred to a pH adjusting tank, and an acidic solution or an alkaline solution is appropriately injected according to the pH of the contaminated soil. The neutral range is adjusted (step S33). The contaminated soil after pH adjustment is transferred to an iron powder mixing tank, and iron powder is added and mixed to attach heavy metal in the contaminated soil to the iron powder (step S34). At this time, iron powder is added based on an addition amount set in advance in the design / planning process (when the addition amount is adjusted by construction management, the addition amount after adjustment). Next, the soil mixed with the iron powder is transferred to the iron powder collecting device, and the iron powder is collected from the soil (step S35). The method for recovering the iron powder is not particularly limited. For example, any of magnetic selection using a magnetic separator or the like, magnetic selection using a gravity separator, or sieve selection using a sieve, etc. Or a sorting method combining a plurality of these. Among these, a recovery method using magnetic sorting is suitable, and efficient recovery is possible.
回収された鉄粉は、繰り返しの使用回数以内であれば、鉄粉投入前に戻され、再び鉄粉混合槽に投入されて、繰り返し使用される（図３の点線矢印参照）。使用回数を超えたときは破過が起こったとして廃棄される。この使用回数も、前述したステップＳ５の設計・計画工程で、繰り返し使用試験により得た鉄粉の破過時期に基づいて設定された使用回数、又は施工管理により土壌の状態等に応じて適切に調整された使用回数である。 If the recovered iron powder is within the number of times of repeated use, it is returned before the iron powder is charged, is again put into the iron powder mixing tank, and is repeatedly used (see the dotted line arrow in FIG. 3). When the number of uses is exceeded, it is discarded as a breakthrough. The number of times of use is also appropriately set according to the number of times of use set based on the breakthrough time of the iron powder obtained by repeated use tests in the design / planning process of step S5 described above, or according to the state of the soil, etc. Adjusted number of uses.
鉄粉が回収された後の土壌は、フィルタープレス等の脱水機に移送されて脱水され、浄化土壌と、ろ水とに分離される。この浄化土壌と、ろ水に対して、定期的に（例えば、土壌の処理量１００ｍ3ごとに１回）公定分析され、浄化の効果確認が行われる。 The soil from which the iron powder has been collected is transferred to a dehydrator such as a filter press, dehydrated, and separated into purified soil and filtered water. An official analysis is periodically performed on the purified soil and filtered water (for example, once every 100 m 3 of soil treated) to confirm the effect of the purification.
また、本実施形態では、浄化後であって脱水前の泥水と、浄化土壌から、それぞれサンプルを採取し、後述の迅速分析工程（ステップＳ５０）で迅速分析する。迅速分析工程では、簡易な装置や手順と迅速分析法によって、より手軽に重金属の溶出量を分析することができるため、公定分析での厳密な効果確認とは別に、日々の浄化の効果を簡易に確認することができる。 In the present embodiment, samples are collected from the muddy water after purification and before dehydration and the purified soil, respectively, and quickly analyzed in a rapid analysis step (step S50) described later. In the rapid analysis process, the amount of elution of heavy metals can be analyzed more easily with simple equipment, procedures and rapid analysis methods. Therefore, the effect of daily purification can be simplified separately from the exact effect confirmation in official analysis. Can be confirmed.
次に、現地分析工程（ステップＳ４０、Ｓ５０）について説明する。この現地分析工程は、施工管理のために、現地での実際の土壌の汚染濃度や土質条件を確認したり、日々の浄化の効果確認を行ったりするための工程であり、現地室内試験工程（ステップＳ４０）と、迅速分析工程（ステップＳ５０）と、を有している。 Next, the on-site analysis process (steps S40 and S50) will be described. This on-site analysis process is a process for confirming the actual soil contamination concentration and soil conditions in the field for construction management, and confirming the effects of daily purification. Step S40) and a quick analysis step (Step S50).
ステップＳ４０の現地室内試験工程では、分析試験を行う前の準備処理を行う。まず、現地の汚染土壌から所定量のサンプルを採取する（ステップＳ４１）。 In the on-site laboratory test process of step S40, a preparatory process before performing an analytical test is performed. First, a predetermined amount of sample is collected from local contaminated soil (step S41).
次に、現地に設けた試験室（例えば、作業用の建物の室内やトラック車両内）において、採取したサンプルのスラリー化と分級を行う（ステップＳ４２）。より具体的には、サンプルが泥岩等の塊状のものである場合は、サンプルを袋等に収容して、ハンマー等の解砕具で細かく砕く。次いで、解砕されたサンプルに水を加えて、卓上ボールミル装置等の簡易な装置を用いてスラリー化する。このとき、サンプルとの固液比が、１：１〜１：２０となるように、水の添加量を調整しながらスラリー化する。そして、スラリー化したサンプルを、篩等の簡易な分級器具によって粒径２ｍｍ以下と、２ｍｍ超に分級する。 Next, the collected sample is slurried and classified in a test room provided at the site (for example, inside a building for work or inside a truck vehicle) (step S42). More specifically, when the sample is a lump such as mudstone, the sample is accommodated in a bag or the like and finely crushed with a crushing tool such as a hammer. Next, water is added to the crushed sample and slurried using a simple device such as a table-top ball mill device. At this time, the slurry is made while adjusting the amount of water added so that the solid-liquid ratio with the sample is 1: 1 to 1:20. Then, the slurry sample is classified into a particle size of 2 mm or less and more than 2 mm by a simple classification device such as a sieve.
次に、粒径２ｍｍ以下のサンプルに対して、鉄粉混合工程（ステップＳ４３）、鉄粉回収工程（ステップＳ４４）、脱水工程（ステップＳ４５）を行う。これらの工程の手順を、図４を参照しながら説明する。適宜の容器内にスラリー化した粒径２ｍｍ以下のサンプルを投入し（ステップＳ４３１）、容器内のサンプルに鉄粉を添加する（ステップＳ４３２）。この添加量は、設計・計画工程にて予め設定された添加量であるが、施工管理によって調整された添加量であってもよい。 Next, an iron powder mixing process (step S43), an iron powder recovery process (step S44), and a dehydration process (step S45) are performed on a sample having a particle size of 2 mm or less. The procedure of these steps will be described with reference to FIG. A sample with a particle size of 2 mm or less slurried is put into an appropriate container (step S431), and iron powder is added to the sample in the container (step S432). This addition amount is an addition amount set in advance in the design / planning process, but may be an addition amount adjusted by construction management.
次に、鉄粉とサンプルを投入して密閉した容器を、卓上ボールミル装置等で振とうさせて、鉄粉とサンプルとを十分に混合し、鉄粉に重金属を吸着させる（ステップＳ４３３）。混合が完了したら、容器内に磁石棒を挿入して攪拌することで、磁石棒に鉄粉を付着させる（ステップＳ４４１）。容器から磁石棒を取り出して、周囲に付着した鉄粉（重金属を吸着した鉄粉）を、ヘラ等を用いてこすり落として鉄粉を回収する（ステップＳ４４２）。回収した鉄粉は、破過時期を確認するための繰り返し使用試験などに用いることができる。破過が起こった後の鉄粉は廃棄される。 Next, the container sealed with iron powder and the sample is shaken with a desktop ball mill device or the like, and the iron powder and the sample are sufficiently mixed to adsorb heavy metal to the iron powder (step S433). When the mixing is completed, the iron bar is attached to the magnet bar by inserting and stirring the magnet bar in the container (step S441). The magnet bar is taken out from the container, and the iron powder (iron powder adsorbing heavy metal) adhering to the periphery is scraped off with a spatula or the like to recover the iron powder (step S442). The recovered iron powder can be used for repeated use tests for confirming the breakthrough time. The iron powder after breakthrough occurs is discarded.
次に、容器内の浄化のサンプルを、必要に応じて篩等による分級した後に、吸引ろ過器等によって脱水し（ステップＳ４５１）、浄化土壌と、ろ水とに分離する（ステップＳ４５２）。浄化土壌とろ水は、次の迅速分析工程（ステップＳ５０）によって分析されるが、以下では浄化土壌の分析手順について説明する。 Next, the purification sample in the container is classified with a sieve or the like as necessary, and then dehydrated with a suction filter or the like (step S451), and separated into purified soil and filtered water (step S452). The purified soil and filtered water are analyzed by the following rapid analysis step (step S50). Hereinafter, the procedure for analyzing the purified soil will be described.
ステップＳ５０の迅速分析工程では、上記ステップＳ４０の現地室内試験工程で浄化し脱水して得られた浄化土から、サンプルを採取する（ステップＳ５１）。採取したサンプルを、試験管等に入れて水で１０倍に希釈し、５分間通常振とうする（ステップＳ５２）。振とうが完了したら、蛍光Ｘ線分析機を用いて、重金属の迅速分析・測定を行う（ステップＳ５３）。 In the quick analysis process of step S50, a sample is collected from the purified soil obtained by purification and dehydration in the on-site laboratory test process of step S40 (step S51). The collected sample is put in a test tube or the like, diluted 10 times with water, and shaken normally for 5 minutes (step S52). When the shaking is completed, rapid analysis / measurement of heavy metals is performed using a fluorescent X-ray analyzer (step S53).
本実施形態では、振とう前に、浄化土壌のサンプルに対して、湿潤状態で１０倍量の水を加えて希釈した後、５分間振とうして分析し、この作業と並行して、電子レンジ法にてサンプルの含水量を測定し、分析結果を含水量で補正している（試験後含水率補正）。そのため、厳密な脱水や水分調整が不要で、簡易に作業することができる。また、公定分析では振とう時間が６時間と定められているが、本実施形態では、通常振とうで５分間振とうしている。本実施形態では、風乾したサンプルではなく、泥土・泥水の状態のサンプルを用いていることから、このような振とう条件であってもサンプルと水とを十分に混合して平衡状態とすることができ、振とう作業をより効率的に行うことができる。 In this embodiment, before shaking, the sample of the purified soil is diluted by adding 10 times the amount of water in a wet state, and then shaken for 5 minutes for analysis. The moisture content of the sample is measured by the range method, and the analysis result is corrected with the moisture content (after-test moisture content correction). Therefore, strict dehydration and moisture adjustment are unnecessary, and the operation can be easily performed. Further, in the official analysis, the shaking time is determined to be 6 hours, but in this embodiment, the shaking is performed for 5 minutes by normal shaking. In this embodiment, since the sample in the state of mud and muddy water is used instead of the air-dried sample, even under such shaking conditions, the sample and water are sufficiently mixed to be in an equilibrium state. And the shaking work can be performed more efficiently.
また、蛍光Ｘ線分析機を用いることで、ＩＣＰ／ＭＳ等を用いた公定分析と比較して、より簡易な設備での分析・測定が可能となる。また、風乾の手間がなく、振とう時間も６時間から５分に短縮できるので、公定分析と比較して、より迅速で、しかも精度よく重金属の分析・測定が可能となる。 In addition, by using a fluorescent X-ray analyzer, analysis and measurement can be performed with simpler equipment as compared with official analysis using ICP / MS or the like. In addition, since there is no need for air drying and the shaking time can be shortened from 6 hours to 5 minutes, it is possible to analyze and measure heavy metals more quickly and more accurately than official analysis.
なお、ここでは試験後含水率補正を適用した分析手順を説明しているが、これに限定されるものではない。事前室内試験で相関を確認し、確認結果によっては事前含水率補正を適用することもできる。また、泥水状の場合は、比重に基づいて１０倍量になるように希釈し、５分間振とうして分析する。水（ろ水）の場合は希釈等せずにそのまま分析する。 In addition, although the analysis procedure which applied the moisture content correction after a test is demonstrated here, it is not limited to this. Correlation can be confirmed in a prior laboratory test, and a prior moisture content correction can be applied depending on the confirmation result. In the case of muddy water, the sample is diluted to 10 times based on the specific gravity and analyzed by shaking for 5 minutes. In the case of water (filtered water), analyze without dilution.
上記のような現地分析工程で取得した重金属の測定結果に基づいて、次のステップＳ６０の運転管理工程で、施工条件の調整を行う。具体的には、例えば、土壌中の重金属の溶出量濃度が基準値を超えている場合は、鉄粉の添加量を増加したり、処理時間を長くしたりする等、浄化条件を適宜調整する。逆に、土壌の汚染度が低い場合は、鉄粉の添加量を少なくしたり、処理時間を短くしたりする。また、鉄粉の繰り返し使用の試験を行った場合は、分析結果に基づいて破過が起こったか否かを確認し、そのときの使用回数に基づいて、本施工での使用回数を調整する。この他にも、分析結果に基づいて、本施工での水の添加量の調整、ｐＨの調整のための酸・アルカリ性溶液等の投入量など、現地での各種施工条件を調整することができる。 Based on the heavy metal measurement results obtained in the field analysis process as described above, the construction conditions are adjusted in the operation management process of the next step S60. Specifically, for example, if the elution concentration of heavy metals in the soil exceeds the reference value, the purification conditions are adjusted as appropriate, such as increasing the amount of iron powder added or increasing the treatment time. . Conversely, when the degree of soil contamination is low, the amount of iron powder added is reduced or the treatment time is shortened. Moreover, when the test of repeated use of iron powder is performed, it is confirmed whether or not breakthrough has occurred based on the analysis result, and the number of times of use in this construction is adjusted based on the number of times of use at that time. In addition, based on the analysis results, it is possible to adjust various on-site construction conditions such as adjustment of the amount of water added in the main construction and the amount of acid / alkaline solution etc. for pH adjustment. .
また、前述したように、ステップＳ３０の実際の浄化工程で浄化して得られた浄化土壌や泥水から採取したサンプルに対して、ステップＳ５０の迅速分析工程を行うこともできる。この場合、浄化の効果確認を、簡易に行うことができる。そして、効果の状態に応じて、再度浄化処理を行うよう運転スケジュールを調整したり、翌日の浄化処理で用いる鉄粉の添加量を調整したりするなど、施工条件を調整することができる。 Further, as described above, the quick analysis step of Step S50 can be performed on the sample collected from the purified soil and mud obtained by purification in the actual purification step of Step S30. In this case, the effect of purification can be easily confirmed. And according to the state of an effect, construction conditions can be adjusted, such as adjusting an operation schedule to perform a purification process again, or adjusting the addition amount of the iron powder used by the purification process on the next day.
以下、本実施形態に係る施工管理方法及び浄化方法の効果を説明する。本実施形態に係る施工管理方法は、予め決められた施工条件に従って、重金属を含有する浄化対象に磁性体を添加し、重金属を吸着した磁性体を所定の選別法により回収することで、浄化対象から重金属を除去する浄化処理を、管理するための施工管理方法である。この施工管理方法は、浄化対象から採取したサンプルから溶出される重金属を迅速分析法によりオンサイトの試験室内で分析する現地分析工程と、現地分析工程での分析結果に基づいて、浄化対象の浄化効果を確認し、施工条件の調整を行う運転管理工程と、を有している。 Hereinafter, effects of the construction management method and the purification method according to the present embodiment will be described. The construction management method according to the present embodiment adds a magnetic substance to a purification target containing heavy metal according to a predetermined construction condition, and collects the magnetic substance that has adsorbed heavy metal by a predetermined sorting method. It is a construction management method for managing the purification process for removing heavy metals from the steel. This construction management method is based on an on-site laboratory that analyzes heavy metals eluted from samples collected from the purification target in an on-site laboratory, and based on the results of the analysis in the local analysis process. And an operation management process for confirming the effect and adjusting the construction conditions.
このように、浄化対象のサンプルに対して、オンサイトの試験室（現地試験室）内で迅速分析法によって重金属を分析するため、公定分析法を用いたときに比べて、より短い時間でより簡易に分析することができる。そのため、日々の浄化の効果確認を、手軽に行うことができる。また、サンプルのバラつき等によって浄化対象の含有量濃度や溶出量濃度や質が流動的に変化する浄化対象の状態を、容易に把握して、その状態や浄化効果に応じて、浄化処理の施工条件を調整することができ、浄化処理を効率的に行うことができる。したがって、重金属を含有、溶出する土壌等の浄化処理を効率的に行うための施工管理を、現地で容易に行うことができる。 In this way, because heavy metals are analyzed in the on-site laboratory (on-site laboratory) by the rapid analysis method for the sample to be purified, it takes less time than the official analysis method. It can be easily analyzed. Therefore, daily purification effects can be confirmed easily. In addition, it is possible to easily grasp the condition of the purification target in which the content concentration, elution concentration, and quality of the purification target are fluidly changed due to sample variation, etc., and implement the purification process according to the state and purification effect. The conditions can be adjusted, and the purification process can be performed efficiently. Therefore, construction management for efficiently performing purification treatment of soil or the like containing or eluting heavy metals can be easily performed locally.
また、本実施形態では、施工条件が、浄化対象への磁性体の添加量、磁性体の繰り返しの使用回数、及び磁性体による浄化対象の処理時間の少なくともいずれか１つを含んでいる。浄化対象の状態や浄化効果に応じて浄化対象への磁性体の添加量を調整することで、磁性体の無駄な使用を抑制できる。また、磁性体の繰り返しの使用回数を調整することで、磁性体が破過を起こす前まで、効率的に使用することができる。その結果、磁性体の使用コストを削減することが可能となる。また、磁性体による浄化対象の処理時間を調整することで、重金属の含有量や溶出量、磁性体の使用量等に応じた処理時間とすることで、浄化の効率化を図ることができる。 In the present embodiment, the construction condition includes at least one of the addition amount of the magnetic substance to the purification target, the number of times the magnetic substance is repeatedly used, and the processing time of the purification target by the magnetic substance. By adjusting the amount of magnetic substance added to the purification target in accordance with the state of the purification target and the purification effect, useless use of the magnetic substance can be suppressed. Further, by adjusting the number of times the magnetic material is used repeatedly, the magnetic material can be used efficiently before breakthrough occurs. As a result, the use cost of the magnetic material can be reduced. Further, by adjusting the treatment time of the object to be purified by the magnetic material, the purification time can be increased by setting the treatment time according to the heavy metal content and elution amount, the usage amount of the magnetic material, and the like.
また、本実施形態では、サンプルが、重金属を含有する浄化対象としての土壌、汚泥、汚水及び泥水のいずれかから採取した浄化前サンプルの場合は、現地分析工程では、オンサイトの試験室内で磁性体を添加して浄化し、磁性体を回収した後に迅速分析法によって分析する。これにより、現地の実際の浄化対象中の重金属の濃度や浄化対象の状態に応じて、適切に施工条件を調整することができる。また、サンプルが、浄化対象を所定の浄化法で浄化した後に採取した浄化後サンプルの場合は、直接に迅速分析法によって分析することができ、日々の浄化の効果確認を、簡易に行うことができるとともに、効果確認の結果に応じて施工条件を好適に調整することができる。 In this embodiment, when the sample is a pre-purification sample collected from any of soil, sludge, sewage, and mud as a purification target containing heavy metals, in the field analysis process, the sample is magnetic in the on-site laboratory. The body is added and purified, and the magnetic substance is collected and analyzed by a rapid analysis method. Thereby, according to the density | concentration of the heavy metal in the actual actual purification object, and the state of purification object, construction conditions can be adjusted appropriately. In addition, if the sample is a post-purification sample collected after purifying the target to be purified by a predetermined purification method, it can be analyzed directly by a rapid analysis method, and daily purification effects can be easily confirmed. In addition, the construction conditions can be suitably adjusted according to the result of the effect confirmation.
また、本実施形態では、現地分析工程では、サンプルを所定の希釈状態となるように水で希釈し、所定時間の振とう後に、蛍光Ｘ線分析によりサンプル中の重金属の溶出量を測定している。このとき、サンプルが土壌等の固体であれば１０倍希釈とすることが好ましい。一方、サンプルが泥水等の固体と水分との混合物の場合は、希釈しないか、または比重が１０倍量となるように水で希釈することが好ましく、サンプルが水の場合は、希釈は不要である。また、振とう時間を１０分以下にすることが好ましく、５分程度とすることがより好ましい。これにより、浄化対象中の重金属を、より迅速かつより簡易に、しかも精度よく分析することができる。なお、現地分析工程における迅速分析法が、蛍光Ｘ線分析機を用いた蛍光Ｘ線分析法に限定されるものではなく、現地に手軽に携帯できる装置で精度よく分析できればよい。例えば、吸光光度法、ストリッピング・ボルタンメトリー法等、重金属の種類や条件等に応じて適宜の手法を用いることができる。 In this embodiment, in the on-site analysis step, the sample is diluted with water so as to be in a predetermined dilution state, and after shaking for a predetermined time, the amount of elution of heavy metal in the sample is measured by fluorescent X-ray analysis. Yes. At this time, if the sample is a solid such as soil, it is preferable to use a 10-fold dilution. On the other hand, when the sample is a mixture of a solid such as muddy water and moisture, it is preferable not to dilute or to dilute with water so that the specific gravity is 10 times, and when the sample is water, dilution is not necessary. is there. The shaking time is preferably 10 minutes or less, more preferably about 5 minutes. Thereby, the heavy metal in the purification target can be analyzed more quickly, more simply, and with high accuracy. The rapid analysis method in the on-site analysis process is not limited to the fluorescent X-ray analysis method using a fluorescent X-ray analyzer, and it is sufficient that the analysis can be performed with high accuracy by a device that can be easily carried on-site. For example, an appropriate method can be used according to the type and conditions of heavy metal, such as an absorptiometric method and a stripping voltammetry method.
また、現地分析工程は、以下のような工程を有するものであってもよい。この工程により、サンプル中の重金属を、より迅速かつより簡易に、しかも精度よく分析することができる。なお、このような工程からなる現地分析工程は、浄化対象が重金属を含有する土壌である場合に好適である。 Moreover, the on-site analysis process may have the following processes. By this step, the heavy metal in the sample can be analyzed more quickly, more easily, and with high accuracy. In addition, the field analysis process which consists of such a process is suitable when the purification | cleaning object is the soil containing a heavy metal.
第一工程：サンプルとの固液比が１：１〜１：２０となるように水を加えてサンプルをスラリー化してスラリーを得る工程。
第二工程：スラリーに磁性体を添加して撹拌する工程。
第三工程：磁性体が添加されたスラリーに磁石体を直接に接触させて磁性体を回収する工程。
第四工程：磁性体の回収後のスラリーを脱水する工程。
第五工程：脱水後のサンプル中の重金属を迅速分析法によって分析する工程。
1st process: The process of adding water and making a sample slurry so that solid-liquid ratio with a sample may be 1: 1-1: 20, and obtaining a slurry.
Second step: A step of adding a magnetic substance to the slurry and stirring.
Third step: A step of bringing the magnetic body into direct contact with the slurry to which the magnetic body has been added to recover the magnetic body.
Fourth step: A step of dehydrating the slurry after collecting the magnetic material.
Fifth step: a step of analyzing heavy metals in the sample after dehydration by a rapid analysis method.
また、本実施形態の浄化方法は、予め決められた施工条件に従って、重金属を含有する浄化対象に磁性体を添加し、重金属を吸着した磁性体を所定の選別法により回収することで、浄化対象から重金属を除去する浄化処理である。具体的には、上述のような本実施形態の施工管理方法により、施工条件を調整する工程を有している。また、浄化対象に含有される重金属を、公定分析法により分析する工程、分析結果に基づいて、施工条件を設定する工程、施工条件に基づいて浄化を行う工程等を有している。 Further, the purification method of the present embodiment adds a magnetic substance to a purification target containing heavy metal according to a predetermined construction condition, and recovers the magnetic substance adsorbing the heavy metal by a predetermined sorting method. It is a purification process that removes heavy metals from. Specifically, it has the process of adjusting construction conditions by the construction management method of this embodiment as described above. Moreover, it has the process of analyzing the heavy metal contained in the purification | cleaning object by a formal analysis method, the process of setting construction conditions based on an analysis result, the process of purifying based on construction conditions, etc.
これにより、現地の実際の重金属の含有状態や溶出状態、浄化対象の状態に応じて、本実施形態の施工管理方法によって適切に調整された施工条件に従って、より効率的に浄化処理することが可能となる。 This makes it possible to purify more efficiently according to the construction conditions appropriately adjusted by the construction management method of the present embodiment according to the actual heavy metal content state, elution state, and state to be purified. It becomes.
本実施形態に係る施工管理方法で行われる迅速分析の効果確認試験と、鉄粉の繰り返し使用での浄化試験を行った。以下、それぞれの試験方法と試験結果を説明する。 The effect confirmation test of the quick analysis performed by the construction management method according to the present embodiment and the purification test by repeated use of iron powder were performed. Hereinafter, each test method and test results will be described.
［迅速分析の効果確認試験］
＜試験方法＞
重金属として砒素を含有し、溶出する土壌（泥岩）の掘削時に得られた泥状の浄化対象土壌に対して、下記表１に示すＣＡＳＥ−１〜ＣＡＳＥ−７の条件で、サンプルを採取し、加水して振とうし、砒素の溶出量（ｍｇ／Ｌ）を測定した。ＣＡＳＥ−１〜ＣＡＳＥ−７について、それぞれ３検体の試験を行った。
[Rapid analysis effect confirmation test]
<Test method>
Samples were collected under the conditions of CASE-1 to CASE-7 shown in Table 1 below, for mud-like soil to be purified that contained arsenic as a heavy metal and eluted during excavation of the soil (mudstone) that eluted. The mixture was shaken with water, and the elution amount of arsenic (mg / L) was measured. Each of CASE-1 to CASE-7 was tested on three specimens.
ＣＡＳＥ−１では、公定分析の振とう条件（風乾＋６時間振とう）とＩＣＰ−ＭＳ装置により分析試験を行った（比較例１）。ＣＡＳＥ−２〜ＣＡＳＥ−７では、本実施形態に係る施工管理方法の上記ステップＳ５１〜Ｓ５３に基づいて、振とう方法、振とう時間及び含水率補正方法を変えて、蛍光Ｘ線分析により分析試験を行った。 In CASE-1, an analytical test was performed using a shake condition of official analysis (air drying + shaking for 6 hours) and an ICP-MS apparatus (Comparative Example 1). In CASE-2 to CASE-7, based on the steps S51 to S53 of the construction management method according to this embodiment, the shaking method, shaking time, and moisture content correction method are changed, and an analytical test is performed by fluorescent X-ray analysis. Went.
下記表１中の「試験後含水率補正」によるＣＡＳＥ−２、４、６の試験例が、実施例１、２、３であり、振とう前にサンプルに対して１０倍量の水を加えて希釈し、振とう後に砒素の溶出量を蛍光Ｘ線分析により測定し、これと並行してサンプルの含水量を電子レンジ法にて測定し、溶出量の測定結果に対して含水率補正を行った。下記表１中の「事前含水率補正」によるＣＡＳＥ−３、５、７の試験例が、参考例１、２、３であり、振とう前にサンプルの含水量を電子レンジ法で迅速に測定し、含水量が１０倍量になるようにサンプルに水を加えて調整し、その後、振とうして砒素の溶出量を蛍光Ｘ線分析により測定した。 The test examples of CASE-2, 4, and 6 by “correction of moisture content after test” in Table 1 below are Examples 1, 2, and 3, and 10 times the amount of water is added to the sample before shaking. The amount of arsenic elution is measured by fluorescent X-ray analysis after shaking. In parallel with this, the moisture content of the sample is measured by the microwave method, and the moisture content correction is performed on the measurement result of the elution amount. went. The test examples of CASE-3, 5, and 7 according to “Preliminary moisture content correction” in Table 1 below are Reference Examples 1, 2, and 3, and the moisture content of the sample is quickly measured by the microwave method before shaking. The sample was adjusted by adding water so that the water content was 10 times, and then shaken, and the elution amount of arsenic was measured by fluorescent X-ray analysis.
＜試験結果＞
試験結果を、図５のグラフに示す。図５は、ＣＡＳＥ−１の公定分析による砒素溶出量の測定値と、ＣＡＳＥ−２〜ＣＡＳＥ−７の迅速分析による測定値の相関を示したものである。この図５のグラフに破線で示す「基準値：０．０１ｍｇ／Ｌ」は、土壌汚染対策法で定められた砒素の濃度の上限値（土壌溶出量基準）である。
<Test results>
The test results are shown in the graph of FIG. FIG. 5 shows the correlation between measured values of arsenic elution amount by official analysis of CASE-1 and measured values by rapid analysis of CASE-2 to CASE-7. The “reference value: 0.01 mg / L” indicated by a broken line in the graph of FIG. 5 is the upper limit value of arsenic concentration (soil elution standard) determined by the Soil Contamination Countermeasures Law.
図５のグラフによれば、迅速分析によるＣＡＳＥ−２、４、６（試験後含水率補正の実施例１、２、３）では、公定分析（比較例１）に近い結果が得られた。この中でも、風乾せず、泥状のまま１０倍の水を加えて５分間の振とう後、蛍光Ｘ線分析により砒素の溶出量を測定し、並行してサンプルの含水量を測定し、測定結果を含水率補正したＣＡＳＥ−６（実施例３）では、公定分析とほぼ同じ結果が得られた。処理土壌は泥状であるため、長時間の振とう時間を必要とせず、５分間の通常振とう後の測定値にて公定分析の結果とほぼ同じ値となったと考えられる。 According to the graph of FIG. 5, in CASE-2, 4, and 6 (Examples 1, 2, and 3 of water content correction after the test) by rapid analysis, a result close to the official analysis (Comparative Example 1) was obtained. Among these, after 10 minutes of water is added in the mud without being air-dried and shaken for 5 minutes, the elution amount of arsenic is measured by fluorescent X-ray analysis, and the moisture content of the sample is measured in parallel. In CASE-6 (Example 3) which corrected the moisture content, the result almost the same as the official analysis was obtained. Since the treated soil is mud, it does not require a long shaking time, and the measured value after the normal shaking for 5 minutes is considered to be almost the same as the result of the official analysis.
以上より、本実施形態の施工管理方法における迅速分析が、公定分析に近い測定精度が得られ、しかもごく短時間での分析が可能であることがわかった。したがって、この迅速分析での結果に基づいて、施工条件を調整することで、浄化処理を、簡易かつ効率的に行うことが可能な施工管理方法及び浄化方法を提供できることがわかった。 From the above, it has been found that the rapid analysis in the construction management method of the present embodiment can obtain measurement accuracy close to the official analysis and can be analyzed in a very short time. Therefore, it was found that a construction management method and a purification method capable of performing the purification process simply and efficiently can be provided by adjusting the construction conditions based on the result of the rapid analysis.
［鉄粉の繰り返し使用での浄化試験］
＜試験方法＞
砒素を含有し、溶出する泥状土壌に対して、所定ｐＨの水溶液と鉄粉を所定量添加し、撹拌後に磁力選別にて鉄粉を回収して泥状土壌を浄化（洗浄）した。その後、遠心分離にて洗浄土と洗浄水とを分離し、それぞれの砒素溶出量（濃度）を測定した。その後、同じ鉄粉を１０回繰返し使用して浄化処理を行い、その都度浄化効果の確認を行った。
[Purification test with repeated use of iron powder]
<Test method>
A predetermined amount of aqueous solution and iron powder having a predetermined pH was added to the muddy soil containing and eluting arsenic, and after stirring, the iron powder was recovered by magnetic separation to purify (wash) the muddy soil. Thereafter, the washing soil and washing water were separated by centrifugation, and the amount of arsenic elution (concentration) was measured. Thereafter, the same iron powder was repeatedly used 10 times for purification treatment, and the purification effect was confirmed each time.
＜試験結果＞
図６に、鉄粉の繰返し使用の浄化試験結果を示す。図６のグラフ中、破線で示す初期値は、浄化前の泥状土壌中の砒素の濃度（溶出量）（ｍｇ／Ｌ）を示す。初期値は、０．０１５ｍｇ／Ｌであった。
<Test results>
FIG. 6 shows the purification test results of repeated use of iron powder. In the graph of FIG. 6, the initial value indicated by a broken line indicates the concentration (elution amount) (mg / L) of arsenic in the muddy soil before purification. The initial value was 0.015 mg / L.
この図６のグラフに示すように、繰り返し使用回数１０回目までは、洗浄土の砒素濃度は、すべて土壌溶出量基準（０．０１ｍｇ／Ｌ）以下であり、大きな変化は見られなかった。しかし、８回目頃から砒素濃度の上昇が見られた。また、洗浄水の砒素濃度は、繰り返し回数の後半（６回目以降）で上昇が見られた。この結果から、鉄粉の吸着能の低下が確認できる。よって、この試験では、使用回数を５回とすることで、鉄粉の吸着能の低下と、鉄粉の使用コストの上昇の双方を抑制しつつ、効率的な浄化処理を行えることがわかる。 As shown in the graph of FIG. 6, the arsenic concentration of the washed soil was not more than the soil elution standard (0.01 mg / L) until the 10th repeated use, and no significant change was observed. However, the arsenic concentration increased from the 8th time. In addition, the arsenic concentration in the cleaning water increased in the second half of the repetition (after the sixth). From this result, it is possible to confirm a decrease in iron powder adsorption capacity. Therefore, in this test, it can be seen that by setting the number of times of use to 5 times, it is possible to perform an efficient purification process while suppressing both a decrease in iron powder adsorption capacity and an increase in iron powder usage cost.
以上のような鉄粉の繰り返し試験を、事前室内試験工程（ステップＳ４）で実行することで、繰り返し使用回数の基準データを取得することができる。また、本施工工程（ステップＳ６）の現地分析工程（ステップＳ４０及びＳ５０）で実行することで、現地の浄化対象の重金属の含有量濃度や溶出量濃度、土質条件等の変化に応じて、繰り返し使用回数を調整することができる。 By executing the repetition test of iron powder as described above in the preliminary indoor test process (step S4), it is possible to acquire reference data on the number of repeated uses. In addition, by executing it in the local analysis process (steps S40 and S50) of this construction process (step S6), it is repeated according to changes in the content concentration, elution amount concentration, soil condition, etc. of the local metal to be purified. The number of uses can be adjusted.
以上、本願の施工管理方法及び浄化方法を、実施形態に基づいて説明してきたが、具体的な構成は、これらの実施形態に限定されるものではなく、特許請求の範囲の各請求項に係る発明の要旨を逸脱しない限り、設計の変更や追加等は許容される。 As mentioned above, although the construction management method and the purification method of this application have been demonstrated based on embodiment, a specific structure is not limited to these embodiment, It concerns on each claim of a claim Design changes and additions are allowed without departing from the scope of the invention.
例えば、上記実施形態では、砒素を含有し、溶出する土壌の浄化とその施工管理に、施工管理方法及び浄化方法を適用した例を示しているが、これに限定されるものではない。鉄粉等の磁性体に吸着される重金属であれば、砒素以外の重金属の浄化とその施工管理にも適用することができる。 For example, in the above-described embodiment, an example in which the construction management method and the purification method are applied to the purification of the soil containing and eluting arsenic and the construction management thereof is not limited to this. Any heavy metal adsorbed on a magnetic material such as iron powder can be applied to purification of heavy metals other than arsenic and construction management thereof.
下記表２に、水銀を含有し、溶出する土壌を鉄粉によって浄化したときの、浄化前後の水銀の溶出量を測定した試験結果を示す。ここでは、２つの試料について試験を行った。下記表２中、「原土水銀溶出量」は、試料１、２の浄化前の汚染土壌（原土）の水銀の溶出量を示す。「試験」は浄化処理の方法を示し、「水洗分級処理」は水のみで洗浄して、篩で分級した比較試験である。「水洗分級＋鉄粉５％」は、土壌に水と５重量％の鉄粉を添加して浄化し、篩で分級したものである。また、脱水して、洗浄土と洗浄水（排水）とに分け、それぞれの水銀の溶出量（濃度）を測定した。土壌と排水の水銀の基準値（土壌溶出量基準）も、下記表２に示した。 Table 2 below shows the test results of measuring the mercury elution amount before and after purification when the soil containing and eluting mercury was purified with iron powder. Here, two samples were tested. In Table 2 below, “rough mercury elution amount” indicates the elution amount of mercury in the contaminated soil (raw soil) before purification of samples 1 and 2. “Test” indicates a purification treatment method, and “water washing classification treatment” is a comparative test in which washing is performed only with water and classification is performed with a sieve. “Washing classification + iron powder 5%” is the result of purifying by adding water and 5% by weight of iron powder to the soil, and classifying with a sieve. Moreover, it dehydrated and divided into washing | cleaning soil and washing water (drainage), and measured the elution amount (concentration) of each mercury. The standard values of mercury for soil and drainage (soil elution standard) are also shown in Table 2 below.
上記表２の結果から、試料１では、原土中の水銀の量が少なかったため、水洗分級処理した比較試験１でも、鉄粉を用いた試験１でも、浄化後土壌及び排水の水銀溶出量（濃度）は基準値未満であった。これに対して、試料２は、原土中の水銀の量が多く、水洗分級処理した比較試験２では、浄化土壌中の水銀溶出量は基準値を超えていた。鉄粉を用いた試験２では、浄化土壌及び排水の水銀溶出量（濃度）は基準値未満であった。 From the results of Table 2 above, in Sample 1, the amount of mercury in the raw soil was small. Therefore, in the comparative test 1 that was subjected to the water washing classification test and the test 1 that used iron powder, Concentration) was less than the standard value. On the other hand, Sample 2 had a large amount of mercury in the raw soil, and in Comparative Test 2 in which the water was classified, the mercury elution amount in the purified soil exceeded the reference value. In Test 2 using iron powder, the mercury elution amount (concentration) of the purified soil and drainage was less than the standard value.
また、下記表３に、鉛を含有し、溶出する土壌を鉄粉によって浄化したときの、浄化前後の鉛の溶出量を測定した試験結果を示す。鉛を含有し、溶出する１つの試料について試験を行ったこと以外、比較試験３、試験３とも、上記水銀を含有し、溶出する土壌を用いた試験と同様にして行った。 Table 3 below shows the test results of measuring the amount of lead elution before and after purification when the soil containing lead and elution was purified with iron powder. Except that the test was conducted on one sample containing and eluting lead, both Comparative Test 3 and Test 3 were conducted in the same manner as the test using the soil containing and eluting mercury.
上記表３の結果から、水洗分級処理した比較試験３では、浄化土壌の鉛溶出量（濃度）が基準値を超えていた。これに対して、鉄粉を用いた試験３では、浄化土壌及び排水の鉛溶出量（濃度）は基準値未満であった。 From the results of Table 3 above, in Comparative Test 3 in which the water washing classification treatment was performed, the lead elution amount (concentration) of the purified soil exceeded the reference value. On the other hand, in Test 3 using iron powder, the amount of lead elution (concentration) in the purified soil and drainage was less than the standard value.
表２、表３の結果から、鉄粉を用いた浄化処理は、水銀、鉛の浄化に好適であることがわかった。したがって、鉄粉等の磁性体を用いた本願の施工管理方法及び浄化方法は、水銀、鉛を含有し、溶出する土壌等の浄化にも適用できることがわかった。また、これら以外の磁性体で吸着可能な重金属を含有、溶出する土壌等の浄化にも適用できることがわかった。 From the results of Tables 2 and 3, it was found that the purification treatment using iron powder is suitable for the purification of mercury and lead. Therefore, it was found that the construction management method and purification method of the present application using a magnetic material such as iron powder can be applied to purification of soil and the like that contain mercury and lead and elute. In addition, it was found that the present invention can also be applied to the purification of soil containing and eluting heavy metals that can be adsorbed by other magnetic substances.
また、本願の施工管理方法及び浄化方法は、汚染土壌処理施設、シールドトンネルの施工現場、山岳トンネル工事現場、杭工事現場等における汚染土壌等の処理に好適に用いることができる。 Moreover, the construction management method and the purification method of the present application can be suitably used for the treatment of contaminated soil at a contaminated soil treatment facility, a shield tunnel construction site, a mountain tunnel construction site, a pile construction site, and the like.
Claims (6)
前記浄化対象から採取したサンプルから溶出される前記重金属を迅速分析法によりオンサイトの試験室内で分析する現地分析工程と、
前記現地分析工程での分析結果に基づいて、前記浄化対象の浄化効果を確認し、前記施工条件の調整を行う運転管理工程と、
を有することを特徴とする施工管理方法。 Purifying that removes the heavy metal from the purification target by adding a magnetic substance to the purification target containing heavy metal and recovering the magnetic body adsorbing the heavy metal by a predetermined sorting method in accordance with predetermined construction conditions A construction management method for managing processing,
An on-site analysis step of analyzing the heavy metal eluted from the sample collected from the purification target in an on-site laboratory by a rapid analysis method;
Based on the analysis result in the on-site analysis process, confirming the purification effect of the purification target, an operation management process for adjusting the construction conditions,
The construction management method characterized by having.
前記サンプルとの固液比が１：１〜１：２０となるように水を加えて前記サンプルをスラリー化してスラリーを得る第一工程と、
前記スラリーに前記磁性体を添加して撹拌する第二工程と、
前記磁性体が添加された前記スラリーに磁石体を直接に接触させて前記磁性体を回収する第三工程と、
前記磁性体の回収後の前記スラリーを脱水する第四工程と、
脱水後の前記サンプル中の前記重金属を迅速分析法によって分析する第五工程と、を有することを特徴とする請求項１〜４のいずれか一項に記載の施工管理方法。 The on-site analysis process includes
A first step for obtaining a slurry by adding water so that the solid-liquid ratio with the sample is 1: 1 to 1:20, and slurrying the sample;
A second step of adding and stirring the magnetic substance to the slurry;
A third step of recovering the magnetic body by bringing the magnet body into direct contact with the slurry to which the magnetic body has been added;
A fourth step of dehydrating the slurry after recovery of the magnetic material;
The construction management method according to claim 1, further comprising a fifth step of analyzing the heavy metal in the sample after dehydration by a rapid analysis method.
請求項１〜５のいずれか一項に記載の施工管理方法により、前記施工条件を調整する工程を有することを特徴とする浄化方法。 Purifying that removes the heavy metal from the purification target by adding a magnetic substance to the purification target containing heavy metal and recovering the magnetic body adsorbing the heavy metal by a predetermined sorting method in accordance with predetermined construction conditions Processing,
The purification method characterized by having the process of adjusting the said construction conditions by the construction management method as described in any one of Claims 1-5.
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