JP2019103989A - Cleaning classification processing method of contaminated soil - Google Patents

Cleaning classification processing method of contaminated soil Download PDF

Info

Publication number
JP2019103989A
JP2019103989A JP2017239666A JP2017239666A JP2019103989A JP 2019103989 A JP2019103989 A JP 2019103989A JP 2017239666 A JP2017239666 A JP 2017239666A JP 2017239666 A JP2017239666 A JP 2017239666A JP 2019103989 A JP2019103989 A JP 2019103989A
Authority
JP
Japan
Prior art keywords
contaminated soil
cation
sand
water
washing
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.)
Pending
Application number
JP2017239666A
Other languages
Japanese (ja)
Inventor
充 土田
Mitsuru Tsuchida
充 土田
公太 永野
Kota Nagano
公太 永野
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shimizu Construction Co Ltd
Shimizu Corp
Original Assignee
Shimizu Construction Co Ltd
Shimizu Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shimizu Construction Co Ltd, Shimizu Corp filed Critical Shimizu Construction Co Ltd
Priority to JP2017239666A priority Critical patent/JP2019103989A/en
Publication of JP2019103989A publication Critical patent/JP2019103989A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02WCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00Technologies for solid waste management
    • Y02W30/50Reuse, recycling or recovery technologies
    • Y02W30/52Mechanical processing of waste for the recovery of materials, e.g. crushing, shredding, separation or disassembly

Landscapes

  • Treatment Of Sludge (AREA)
  • Separation Of Solids By Using Liquids Or Pneumatic Power (AREA)
  • Processing Of Solid Wastes (AREA)
  • Separation Of Suspended Particles By Flocculating Agents (AREA)

Abstract

To provide a cleaning classification processing method of contaminated soil capable of performing cleaning classifying of a contaminated soil with good efficiency.SOLUTION: The method contains: a first step S1 of adding a water W1 to a contaminated soil 100, classifying by wet sieving 11 for separating a coarse grain fraction 102 and further classifying for a slurry of a sand 101 into a sand fraction 104 and a fine grain fraction 103; a second step S2 of cleaning of a sand fraction 104 classified in the first step S1; and a third step S3 of coagulation sedimentation of the fine grain fraction 103 classified in the first step S1 for separating into a sedimented sludge 105 and a treatment water W2, dehydrating the sedimented sludge 105 for separating into a concentrated residue 106 and a treatment water W3; in the first step S1, a cation addition step S12 of adding a cation I to the contaminated soil 100 is conducted.SELECTED DRAWING: Figure 1

Description

本発明は、汚染土壌の洗浄分級処理方法に関する。   The present invention relates to a method for cleaning and classifying contaminated soil.

各地から収集された放射能物質汚染土壌(汚染土壌)は、受入・分別処理施設(前処理施設)に搬入されて前処理され、前処理後に中間貯蔵施設へ搬送されて貯蔵されている。前処理施設では、膨大な量の汚染土壌に対応できるように、高い処理能力を確保する必要がある。このため、前処理施設では、各処理設備をベルトコンベアで接続し、汚染土壌の各処理設備間を移動をベルトコンベアで行いながら連続処理を行っている。
前処理施設では、汚染土壌を粒径別、汚染濃度別に分別する分別工程が行われている。分別工程では、汚染土壌をふるいにかけて粒径別に分別している。分別工程の前には、汚染土壌に改質材を投入し、分別工程においてふるいの目詰まりが生じないようにしている。
Radioactive substance contaminated soil (contaminated soil) collected from various places is carried into the receiving / separating treatment facility (pretreatment facility), pretreated and transported to the intermediate storage facility after storage and stored. In pretreatment facilities, it is necessary to secure high treatment capacity so that it can cope with a huge amount of contaminated soil. Therefore, in the pretreatment facility, each treatment facility is connected by a belt conveyor, and continuous treatment is performed while moving each treatment facility of the contaminated soil with the belt conveyor.
At the pre-treatment facility, a separation process is conducted to separate the contaminated soil according to particle size and concentration. In the separation step, the contaminated soil is sieved and separated according to particle size. Prior to the separation process, a modifier is added to the contaminated soil so that clogging of the sieve does not occur in the separation process.

中間貯蔵施設に貯蔵される汚染土壌は、膨大な量であるため、放射能濃度が8000Bq/kg以下の汚染土壌を再利用することが考えられている。また、放射能濃度が8000Bq/kgを超える汚染土壌についても、洗浄分級処理による浄化によって8000Bq/kg以下の土壌とし、再利用することも選択肢の一つと考えられている。
洗浄分級処理のフローは、例えば特許文献1乃至4などに開示されている。洗浄分級処理では、汚染土壌に加水して、遠心分離式湿式分級器や沈殿分離式分級器などで汚染された細粒子分と非汚染の砂分とを分別している。また、汚染された細粒子分については、凝集沈殿させて、凝集沈殿した残渣を脱水機にて脱水している。
Since the amount of contaminated soil stored in the intermediate storage facility is enormous, it is considered to reuse the contaminated soil having a radioactivity concentration of 8,000 Bq / kg or less. In addition, it is considered as one of the options to use contaminated soil with radioactivity concentration exceeding 8000 Bq / kg as soil with 8000 Bq / kg or less by purification by washing classification processing.
The flow of the washing classification process is disclosed, for example, in Patent Documents 1 to 4. In the washing and classification process, fine particles and non-contaminated sand are separated by adding water to the contaminated soil and using a centrifugal wet classifier or a precipitation classifier. The contaminated fine particles are coagulated and precipitated, and the coagulated and precipitated residue is dewatered by a dehydrator.

特開2013−092428号公報JP, 2013-092428, A 特開2013−178147号公報JP, 2013-178147, A 特開2013−178148号公報JP, 2013-178148, A 特開2013−238484号公報JP, 2013-238484, A

前処理施設での分別工程の前に汚染土壌に投入される改質材には、吸水性高分子ポリマーが含まれていることが多い。このため、洗浄分級処理において改質材が投入された汚染土壌に加水を行うと、改質材が水を大量(改質材中の吸水性高分子ポリマー自重の数十倍〜数百倍の量)に取り込んでしまい、洗浄分級処理、特に脱水工程に負担がかかることが想定される。
さらに、脱水工程の機能が低下すると、浄化できなかった土壌として残る汚染土量(残渣)も多くなり、洗浄分級処理による汚染土壌の減容化の効果が大きく低下する懸念がある。
また、水を含んだ吸水性高分子ポリマーが、汚染土壌の細粒子分と同様の挙動をしてしまい、各工程において悪影響が出ることがある。
The modifier introduced into the contaminated soil prior to the separation process at the pretreatment facility often contains a water-absorbing polymer. For this reason, when the contaminated soil to which the modifier has been added is subjected to water addition in the washing and classification treatment, the modifier has a large amount of water (a few dozen times to a few hundred times the weight of the water absorbing polymer in the modifier). Amount), and it is assumed that the washing classification process, in particular the dehydration step, is burdened.
Furthermore, if the function of the dewatering process is reduced, the amount of contaminated soil (residue) remaining as soil that could not be cleaned is increased, and there is a concern that the effect of volume reduction of the contaminated soil by the washing classification process is greatly reduced.
In addition, the water-absorbent polymeric polymer containing water behaves in the same manner as the fine particles in the contaminated soil, which may adversely affect each step.

そこで、本発明は、汚染土壌の洗浄分級処理を効率よく行うことができる汚染土壌の洗浄分級処理方法を提供することを目的とする。   Then, an object of this invention is to provide the washing classification processing method of the contaminated soil which can perform washing | cleaning classification processing of contaminated soil efficiently.

上記目的を達成するため、本発明に係る汚染土壌の洗浄分級処理方法は、汚染土壌に水を添加し、湿式ふるい分級処理して粗粒子分を分離したスラリー状の土砂を砂分と細粒子分とにさらに分級処理する第1工程と、前記第1工程で分級処理した砂分を洗浄処理する第2工程と、前記第1工程で分級処理した細粒子分を凝集沈殿させて沈殿汚泥と処理水とに分離し、沈殿汚泥を脱水処理して濃縮残渣と処理水とに分離する第3工程と、を有し、前記第1工程では、前記汚染土壌に陽イオンを添加する陽イオン添加工程を行うことを特徴とする。   In order to achieve the above object, the method for washing and classifying contaminated soil according to the present invention comprises adding water to the contaminated soil and carrying out wet sieving classification to separate coarse particles from slurry-like sediment and sand and fine particles The first step of further classification treatment in the second step, the second step of washing treatment of the sand fraction classified in the first step, and the fine particle fraction classified in the first step are coagulated and precipitated to form precipitated sludge Separating the treated sludge into treated water and dewatering the sedimented sludge to separate it into concentrated residue and treated water; and adding cation to the contaminated soil in the first step. It is characterized by performing a process.

汚染土壌に吸水性高分子ポリマーを含む改質材が投入されていた場合に、吸水性高分子ポリマーの体積が吸水によって増大すると、増大した吸水性高分子ポリマーが細粒子分と同様の挙動をしてオーバーフロー側に移動するため、その後の工程に多大な負担を強いることになる。
これに対し、本発明では、第1分級工程において陽イオン添加工程を行うため、汚染土壌に吸水性高分子ポリマーを含む改質材が投入されていた場合に、吸水性高分子ポリマーの吸水機能を低下させて、吸水性高分子ポリマーの吸水量を少なくすることができる。
これにより、後の工程の負担が軽減でき、後の工程を効率よく行うことができる。特に、第3工程の脱水処理における負荷を少なくすることができる。
When the modifier containing the water absorbing polymer is added to the contaminated soil, when the volume of the water absorbing polymer increases due to water absorption, the increased water absorbing polymer behaves like fine particles. And move to the overflow side, which imposes a large burden on the subsequent steps.
On the other hand, in the present invention, since the cation addition step is carried out in the first classification step, the water absorbing function of the water absorbing polymer when the modifier containing the water absorbing polymer is added to the contaminated soil. Can be reduced to reduce the amount of water absorption of the water-absorbent polymer.
As a result, the burden on the subsequent steps can be reduced, and the subsequent steps can be performed efficiently. In particular, the load in the dehydration process of the third step can be reduced.

また、本発明に係る汚染土壌の洗浄分級処理方法では、前記陽イオン添加工程は、前記汚染土壌に前記水とともに前記陽イオンを添加してもよい。
このようにすることにより、陽イオンが汚染土壌に含まれる吸水性高分子ポリマーの吸水機能を初期段階で阻害することができるため、各工程を効率よく行うことができる。
Further, in the method for washing and classifying contaminated soil according to the present invention, the cation addition step may add the cation together with the water to the contaminated soil.
By doing so, since the cation can inhibit the water absorption function of the water-absorbent polymer contained in the contaminated soil at an early stage, each step can be performed efficiently.

また、本発明に係る汚染土壌の洗浄分級処理方法では、前記陽イオン添加工程は、前記汚染土壌のうちの湿式ふるい分級処理して前記粗粒子分を分離した後の前記スラリー状の土砂に前記陽イオンを添加してもよい。
このようにすることにより、汚染土壌全体ではなく粗粒子分を分離したスラリー状の土砂に陽イオンを添加するため、汚染土壌全体に陽イオンを添加する場合と比べて、陽イオンの使用量を減らすことができる。また、粗粒子分を分離したスラリー状の土砂に陽イオンを確実に添加することができるため、スラリー状の土砂を細粒子分と砂分とにさらに分級する処理の負荷を少なくすることができる。
Further, in the method for washing and classifying contaminated soil according to the present invention, the cation addition step is carried out in the slurry-like soil after the coarse particle is separated by wet sieving classification of the contaminated soil. Cations may be added.
In this way, since cations are added to the slurry-like soil from which coarse particles have been separated rather than the entire contaminated soil, the amount of cations used is greater than when cations are added to the entire contaminated soil. It can be reduced. In addition, since cations can be reliably added to slurry-like earth and sand from which coarse particles have been separated, the load of processing for further classifying slurry-like earth and sand into fine particles and sand can be reduced. .

また、本発明に係る汚染土壌の洗浄分級処理方法では、前記陽イオン添加工程は、前記汚染土壌のうちの前記砂分と前記細粒子分とに分級処理された後の前記細粒子分に前記陽イオンを添加してもよい。
このようにすることにより、汚染土壌全体ではなく細粒子分のみに陽イオンを添加するため、汚染土壌全体に陽イオンを添加する場合と比べて、陽イオンの使用量を減らすことができる。また、細粒子分に陽イオンを確実に添加することができるため、第3工程の脱水処理における負荷を確実に少なくすることができる。
Further, in the method for washing and classifying contaminated soil according to the present invention, the cation addition step is carried out for the fine particles after being classified into the sand and the fine particles in the contaminated soil. Cations may be added.
By doing so, the amount of cations used can be reduced as compared to the case where cations are added to the entire contaminated soil, since cations are added only to the fine particles instead of the entire contaminated soil. In addition, since cations can be reliably added to the fine particles, the load in the dehydration treatment of the third step can be surely reduced.

本発明によれば、汚染土壌の洗浄分級処理を効率よく行うことができる。   ADVANTAGE OF THE INVENTION According to this invention, the washing classification process of contaminated soil can be performed efficiently.

本発明の実施形態による汚染土壌の洗浄分級処理方法の一例を示す模式図である。It is a schematic diagram which shows an example of the washing classification processing method of the contaminated soil by embodiment of this invention.

以下、本発明の実施形態による汚染土壌の洗浄分級処理方法について、図1に基づいて説明する。
図1に示すように、本実施形態による汚染土壌の洗浄分級処理方法は、セシウムなどの放射能物質により汚染された汚染土壌100を中間貯蔵施設で貯蔵する前に洗浄分級する方法である。
本実施形態では、各地から搬送された汚染土壌100は、受入・分別処理施設(前処理施設)で粒径別、濃度別に分別された後に洗浄分級施設において洗浄分級され、放射能濃度が8000Bq/kg以下の土壌は再利用され、放射能濃度が8000Bq/kgを超える汚染土壌100は中間貯蔵施設で貯蔵されるように設定されている。
Hereinafter, a method of washing and classifying contaminated soil according to an embodiment of the present invention will be described based on FIG.
As shown in FIG. 1, the method of the present invention for cleaning and classifying contaminated soil according to the present embodiment is a method of cleaning and classifying contaminated soil 100 contaminated with a radioactive substance such as cesium prior to storage in an intermediate storage facility.
In this embodiment, the contaminated soil 100 transported from various places is separated by particle size and concentration by the receiving and separating treatment facility (pretreatment facility) and then classified by washing and classification facility, and the radioactivity concentration is 8000 Bq / The soil of kg or less is recycled, and the contaminated soil 100 having a radioactivity concentration of more than 8000 Bq / kg is set to be stored at an intermediate storage facility.

受入・分別処理施設では、ふるいによって汚染土壌100を粒径別に分別している。このとき、ふるいの目詰まりを防止するために汚染土壌100に吸水性高分子ポリマーを含む改質材を投入している。このため。洗浄分級施設において洗浄分級される汚染土壌100には、吸水性高分子ポリマーを含む改質材が含まれている。   In the receiving / separating treatment facility, the contaminated soil 100 is sorted according to the particle size by a sieve. At this time, in order to prevent clogging of the sieve, a modifier including a water absorbing polymer is introduced into the contaminated soil 100. For this reason. The contaminated soil 100 to be washed and classified in the washing and classification facility contains a modifier containing a water absorbing polymer.

本実施形態による汚染土壌の洗浄分級処理方法は、汚染土壌100に水W1を添加し、湿式ふるい11で分級処理して粗粒子分102を分離したスラリー状の土砂101を細粒子分103と砂分104とにさらに分級処理する第1工程S1と、第1工程S1で分級処理した砂分104を洗浄処理する第2工程S2と、第1工程S1で分級処理した細粒子分103を凝集沈殿させて沈殿汚泥105と処理水W2とに分離し、沈殿汚泥105を脱水処理して濃縮残渣106と処理水W3とに分離する第3工程S3と、を有している。   In the method for washing and classifying contaminated soil according to the present embodiment, water W1 is added to the contaminated soil 100, and classification processing with a wet sieve 11 is performed to separate coarse particles 102 by separating slurry coarse sediments 101 into fine particles 103 and sand. The first step S1 of further classification to the portion 104, the second step S2 of washing the sand portion 104 classified in the first step S1, and the fine particle portion 103 classified in the first step S1 are aggregated and precipitated. And the third step S3 of separating the sedimented sludge 105 into the treated water W2 and dewatering the sedimented sludge 105 to separate it into the concentrated residue 106 and the treated water W3.

(第1工程S1)
第1工程S1は、汚染土壌100に水W1を添加する加水工程S11と、加水工程S11と同時または加水工程S11を前後して汚染土壌100に陽イオンIを添加する陽イオン添加工程S12と、加水工程S11および陽イオン添加工程S12の後に湿式ふるい11を用いて汚染土壌100から粗粒子分102を分離し、スラリー状の土砂101とする第1分級工程S13と、第1分級工程S13の後に遠心分離式湿式分級器12を用いてスラリー状の土砂101を砂分104と細粒子分103とに分級する第2分級工程S14と、を有している。
(First step S1)
The first step S1 includes a water adding step S11 in which water W1 is added to the contaminated soil 100, and a cation adding step S12 in which a cation I is added to the contaminated soil 100 simultaneously with or after the water adding step S11. After the water addition step S11 and the cation addition step S12, the coarse particle fraction 102 is separated from the contaminated soil 100 using the wet sieve 11 to make a slurry-like soil 101, and after the first classification step S13 There is a second classification step S14 in which the slurry-like sediment 101 is classified into the sand component 104 and the fine particle component 103 using the centrifugal wet type classifier 12.

加水工程S11では、汚染土壌100の重量、粒径、放射能濃度などに応じて算出された量の水W1を汚染土壌100に添加する。
陽イオン添加工程S12では、加水工程S11で加水される水W1の量に応じて算出された量の陽イオンIを汚染土壌100に添加する。汚染土壌100への陽イオンIの添加は、例えば、消石灰などを汚染土壌100に添加することで行われている。
In the water addition step S11, water W1 of an amount calculated according to the weight, particle size, radioactivity concentration and the like of the contaminated soil 100 is added to the contaminated soil 100.
In the cation addition step S12, the cation I in an amount calculated according to the amount of water W1 to be hydrolyzed in the water addition step S11 is added to the contaminated soil 100. The addition of the cation I to the contaminated soil 100 is performed, for example, by adding slaked lime or the like to the contaminated soil 100.

第1分級工程S13では、湿式ふるい11として、例えば、振動ふるいを用いている。湿式ふるい11は、異物を選別して、礫・粗砂とそれ以下のスラリー状の土砂101とに分級するように構成されており、網面を内部に備えている。湿式ふるい11には、公知の装置を使用することができる。なお、湿式ふるい11によって粗粒子分102を分離しておくことにより、表面処理工程S21、スクラビング工程S22および洗浄工程S23の効率を向上させることができる。   In the first classification step S13, as the wet sieve 11, for example, a vibrating sieve is used. The wet sifter 11 is configured to sort foreign matter and classify it into coarse sand and coarse sand and slurry-like earth and sand 101 below it, and has a mesh surface inside. A well-known apparatus can be used for the wet sieve 11. In addition, the efficiency of surface treatment process S21, scrubbing process S22, and washing | cleaning process S23 can be improved by separating the coarse particle part 102 by the wet sieve 11. FIG.

第2分級工程S14では、遠心分離式湿式分級器12を用いて、粗粒子分102を除いたスラリー状の土砂101を砂分104と細粒子分103とに分級処理する。このとき砂分104および細粒子分103には、放射能物質が含まれている。なお、遠心分離式湿式分級器12に代えて沈降分離式分級器を用いてもよい。   In the second classification step S14, the slurry-like sediment 101 excluding the coarse particle content 102 is classified into a sand content 104 and a fine particle content 103 using the centrifugal wet type classifier 12. At this time, the sand portion 104 and the fine particle portion 103 contain radioactive substances. In place of the centrifugal wet-type classifier 12, a sedimentation-type classifier may be used.

遠心分離式湿式分級器12は、例えば、円筒状に形成されるとともに、その底部が円錐形状に形成された容器からなり、スラリー状の土砂101を導入する上部流入口と、アンダーフローを取り出す下部流出口と、オーバーフローを取り出す上部流出口とを備えている。上部流入口から入ったスラリー状の土砂101は、円筒容器の円周方向に高速で供給されることにより、回転運動を起こし、回転流となって、円錐頂部に向かって進む。この時、スラリー状の土砂101中の比重の重い粒子は遠心力により周壁に集まり、次第にアンダーフロー出口(下部流出口)に向かい、濃縮して排出される。
一方、液体と比重の軽い粒子は、円筒容器の中央部を渦流となって上昇し、オーバーフロー出口(上部流出口)から排出される。なお、遠心分離式湿式分級器12としては、公知の装置を使用することができる。そして、放射性物質は細粒子分103に多く付着・吸着しているため、遠心分離式湿式分級器12で分級することにより、多くの放射性物質を洗浄処理土から除去することができる。この分級の処理回数は、適宜設定されるが、1回以上行うのが好ましい。
The centrifugal wet type classifier 12 is, for example, formed in a cylindrical shape, and is formed of a container whose bottom is formed in a conical shape, and is an upper inlet for introducing the slurry-like earth and sand 101 and a lower portion for taking out underflow. An outlet and an upper outlet for taking out the overflow are provided. The slurry-like earth and sand 101 which has entered from the upper inlet port is supplied at high speed in the circumferential direction of the cylindrical container to cause rotational movement to become a rotational flow and to advance toward the conical top. At this time, heavy particles having a specific gravity in the slurry-like soil 101 gather on the peripheral wall by centrifugal force, and gradually travel toward the underflow outlet (lower outlet), and are concentrated and discharged.
On the other hand, the liquid and light specific gravity particles rise in a swirling manner in the central portion of the cylindrical container and are discharged from the overflow outlet (upper outlet). In addition, as a centrifugal-type wet-type classifier 12, a well-known apparatus can be used. Then, since a large amount of radioactive substance adheres to and adsorbs to the fine particle portion 103, by classifying it with the centrifugal wet classifier 12, many radioactive substances can be removed from the treated soil. The number of classification processes is appropriately set, but is preferably performed once or more.

(第2工程S2)
第2工程S2は、第2分級工程S14で分級された砂分104の土壌粒子の表面に付着している放射能物質を剥離し易くさせる表面処理工程S21と、表面処理工程S21の後に砂分104の表面の放射能物質を剥離させるスクラビング工程S22と、スクラビング工程S22の後に砂分104の表面から剥離された放射能物質を含む細粒子分などを回収するとともに砂分104から細粒子分が剥離された洗浄処理砂107を取り出す洗浄工程S23と、洗浄工程S23で取り出された洗浄処理砂107に残った放射能物質を含む細粒子分を、脱水処理装置を用いて抽出する放射能物質抽出工程S24と、を有している。
(2nd process S2)
The second step S2 includes a surface treatment step S21 for facilitating exfoliation of the radioactive substance adhering to the surface of the soil particles of the sand fraction 104 classified in the second classification step S14, and a sand fraction after the surface treatment step S21 In the scrubbing step S22 for peeling radioactive substances on the surface of the surface 104 and the fine particles containing radioactive substances peeled off from the surface of the sand portion 104 after the scrubbing step S22, the fine particles are removed from the sand portion 104 Radioactive substance extraction which extracts fine particles including radioactive substances remaining in the washed sand 107 taken out in the washing step S23 for taking out the washed treated sand 107 and the washed step S23 using the dehydration processing device And S24.

表面処理工程S21では、第2分級工程S14で分級処理した砂分104を表面処理槽21に溜め、この表面処理槽21内で砂分104に分散剤を添加することで、砂分104の土壌粒子の表面に付着している放射能物質を細粒子分とともに剥離し易くさせる。
スクラビング工程S22では、スクラバー22を用いて、表面処理工程S21で表面処理された砂分104の表面の放射能物質を含んだ細粒子分を攪拌することによるもみ洗いにより剥離させて離脱処理することで、砂分104に付着している放射能物質を含んだ細粒子分を離脱させる。
洗浄工程S23では、フローテーション装置23を用いて、スクラバー22からフローテーション装置23に投入された砂分104のうちスクラビング工程S22による離脱物(放射能物質および放射能物質を含んだ細粒子分など)108をフローテーション処理によって発生させたフロスにより回収するとともに、離脱物が除去された洗浄処理砂107を取り出す。
放射能物質抽出工程S24では、洗浄工程S23で取り出された洗浄処理砂107に残った放射能物質110を、抽出槽24において、例えば、セシウム抽出薬剤の溶液などにより抽出し、脱水処理装置25を用いてさらに濃度の低い2次洗浄処理砂(低濃度洗浄処理砂)109を脱水処理する。
In the surface treatment step S21, the sand component 104 classified in the second classification step S14 is stored in the surface treatment tank 21 and a dispersant is added to the sand component 104 in the surface treatment tank 21, whereby the soil of the sand component 104 is obtained. The radioactive substance adhering to the surface of the particles is made easy to exfoliate with the fine particles.
In the scrubbing step S22, the fine particles containing the radioactive substance on the surface of the sand 104 surface-treated in the surface treatment step S21 are stirred off using a scrubber 22 so that the particles are peeled off and removed by rubbing. Thus, the fine particles containing radioactive substances adhering to the sand 104 are released.
In the washing step S23, the flotation device 23 is used to separate the sand components 104 introduced from the scrubber 22 into the flotation device 23 in the scrubbing step S22 (such as radioactive material and fine particles containing radioactive material) ) 108 is recovered by floss generated by flotation, and the washed sand 107 from which the separated material has been removed is taken out.
In the radioactive substance extraction step S24, the radioactive substance 110 remaining in the washed sand 107 taken out in the washing step S23 is extracted in the extraction tank 24 with, for example, a solution of a cesium-extracted drug, etc. The secondary cleaning treated sand (low density washed treated sand) 109 having a lower density is dewatered using this.

(第3工程S3)
第3工程S3では、第2分級工程S14で分級された細粒子分103を凝集沈殿装置31で処理水W2と沈殿汚泥105とに分離する分離工程S31と、分離工程S31で分離された沈殿汚泥105を脱水する脱水工程S32と、を有している。
本実施形態の第3工程S3では、第2分級工程S14で分級された細粒子分103に加え、洗浄工程S23における洗浄工程S23によるフロス、および放射能物質抽出工程S24による処理溶液が凝集沈殿装置31に送られるように構成されている。
(Third step S3)
In the third step S3, a separation step S31 in which the fine particle fraction 103 classified in the second classification step S14 is separated into the treated water W2 and the settling sludge 105 by the coagulation settling apparatus 31, and the settling sludge separated in the separation step S31 And dewatering step S 32 for dewatering 105.
In the third step S3 of this embodiment, in addition to the fine particle fraction 103 classified in the second classification step S14, the floss in the washing step S23 in the washing step S23, and the treatment solution in the radioactive substance extraction step S24 is an aggregation and precipitation device It is configured to be sent to 31.

分離工程S31では、凝集沈殿装置31を使用し、細粒子分103を含んだ懸濁水に凝集剤を添加・撹拌し、懸濁水中の微細な浮遊物を大きな沈殿汚泥105として沈殿させ、沈殿汚泥105と清澄な処理水W2とに分離する。このとき、細粒子分103が放射能物質(フロス、処理溶液)を吸着し、凝集沈殿により沈殿汚泥105となる。
脱水工程S32では、プレス脱水装置32を使用し、沈殿汚泥105を脱水処理し、濃縮残渣106と処理水W3とに分離する。このプレス脱水装置32は、公知の加圧式濾過装置(ベルトプレスやフィルタープレス)等であり、濾布等からなるフィルターとプレス機を備えている。
In the separation step S31, the flocculating agent is added to the suspension water containing the fine particle content 103 and stirred using the flocculating and settling apparatus 31 to precipitate fine suspended solids in the suspension water as large settling sludge 105, and settling sludge It separates into 105 and the clear treated water W2. At this time, the fine particle portion 103 adsorbs a radioactive substance (floss, treatment solution), and becomes coagulated sedimentation to form a sedimented sludge 105.
In the dewatering step S32, the precipitated sludge 105 is dewatered using the press dewatering device 32, and separated into the concentrated residue 106 and the treated water W3. The press dewatering device 32 is a known pressure type filtration device (belt press or filter press) or the like, and includes a filter made of a filter cloth or the like and a press.

次に、上述した本発明の実施形態による汚染土壌の洗浄分級処理方法の作用・効果について図面を用いて説明する。   Next, the operation and effects of the method for the cleaning and classifying treatment method for the contaminated soil according to the embodiment of the present invention described above will be described using the drawings.

汚染土壌100に吸水性高分子ポリマーを含む改質材が投入されていた場合に、吸水性高分子ポリマーの体積が吸水によって増大すると、増大した吸水性高分子ポリマーが細粒子分と同様の挙動をしてオーバーフロー側に移動するため、その後の工程に多大な負担を強いることになる。
これに対し、上述した本実施形態による汚染土壌の洗浄分級処理方法では、第1分級工程S13において陽イオン添加工程S12を行うため、汚染土壌100に吸水性高分子ポリマーを含む改質材が投入されていた場合に、吸水性高分子ポリマーの吸水機能を低下させて、吸水性高分子ポリマーの吸水量を少なくすることができる。
これにより、後の工程の負担が軽減でき、後の工程を効率よく行うことができる。特に、第3工程S3の脱水処理における負荷を少なくすることができる。
When the modifier containing the water absorbing polymer is added to the contaminated soil 100, when the volume of the water absorbing polymer increases due to water absorption, the increased water absorbing polymer behaves like fine particles. And move to the overflow side, which imposes a great burden on the subsequent steps.
On the other hand, in the method of the present invention for washing and classifying contaminated soil according to the present embodiment described above, since the cation addition step S12 is performed in the first classification step S13, a modifier containing a water absorbing polymer is added to the contaminated soil 100. If the water absorption property of the water absorbent polymer is reduced, the water absorption capacity of the water absorbent polymer can be reduced.
As a result, the burden on the subsequent steps can be reduced, and the subsequent steps can be performed efficiently. In particular, the load in the dehydration process of the third step S3 can be reduced.

また、本実施形態に係る汚染土壌の洗浄分級処理方法では、陽イオン添加工程S12は、汚染土壌100に水W1とともに陽イオンIを添加していることにより、陽イオンIが汚染土壌100に含まれる吸水性高分子ポリマーの吸水機能を初期段階で阻害することができるため、各工程を効率よく行うことができる。   In addition, in the method for washing and classifying contaminated soil according to the present embodiment, the cation addition step S12 includes the cation I in the contaminated soil 100 by adding the cation I to the contaminated soil 100 together with the water W1. Each step can be performed efficiently because the water absorption function of the water-absorbent polymer can be inhibited at an early stage.

以上、本発明による汚染土壌の洗浄分級処理方法の実施形態について説明したが、本発明は上記の実施形態に限定されるものではなく、その趣旨を逸脱しない範囲で適宜変更可能である。
例えば、上記の実施形態では、陽イオン添加工程S12は、汚染土壌100に水W1とともに陽イオンIを添加しているが、以下のようにしてもよい。
例えば、陽イオン添加工程S12は、第1分級工程S13の後のスラリー状の土砂101に陽イオンIを添加してもよい。
このようにすることにより、汚染土壌100全体ではなく粗粒子分102を分離したスラリー状の土砂101に陽イオンIを添加するため、汚染土壌100全体に陽イオンIを添加する場合と比べて、陽イオンIの使用量を減らすことができる。
As mentioned above, although embodiment of the washing classification processing method of the contaminated soil by this invention was described, this invention is not limited to said embodiment, It can change suitably in the range which does not deviate from the meaning.
For example, in the above embodiment, the cation I is added to the contaminated soil 100 together with the water W1 in the cation addition step S12, but may be as follows.
For example, in the cation addition step S12, the cation I may be added to the slurry-like soil 101 after the first classification step S13.
In this way, cation I is added to the slurry-like soil 101 from which the coarse particle portion 102 has been separated instead of the whole contaminated soil 100, so compared to the case where cation I is added to the whole contaminated soil 100, The amount of cation I used can be reduced.

また、例えば、陽イオン添加工程S12は、第2分級工程S14の後の細粒子分103に陽イオンIを添加してもよい。
このようにすることにより、汚染土壌100全体ではなく細粒子分103のみに陽イオンを添加するため、汚染土壌100全体に陽イオンIを添加する場合と比べて、陽イオンIの使用量を減らすことができる。また、細粒子分103に陽イオンを確実に添加することができるため、第3工程の脱水工程S32における負荷を確実に少なくすることができる。
Also, for example, in the cation addition step S12, the cation I may be added to the fine particle fraction 103 after the second classification step S14.
By doing this, the amount of cation I used is reduced as compared with the case where cation I is added to the entire contaminated soil 100, since cations are added only to the fine particle portion 103 instead of the entire contaminated soil 100. be able to. Further, since cations can be reliably added to the fine particle portion 103, the load in the dehydration step S32 of the third step can be surely reduced.

100 汚染土壌
102 粗粒子分
101 スラリー状の土砂
103 細粒子分
104 砂分
105 沈殿汚泥
106 濃縮残渣
I 陽イオン
W1 水
W2 処理水
W3 処理水
S1 第1工程
S2 第2工程
S3 第3工程
S12 陽イオン添加工程
100 Contaminated soil 102 Coarse particle content 101 Slurry-like sediment 103 Fine particle content 104 Sand content 105 Sedimented sludge 106 Concentrated residue I Cation W1 Water W2 Treated water W3 Treated water S1 First process S2 Second process S2 Second process S3 Third process S12 Ion addition process

Claims (4)

汚染土壌に水を添加し、湿式ふるい分級処理して粗粒子分を分離したスラリー状の土砂を砂分と細粒子分とにさらに分級処理する第1工程と、
前記第1工程で分級処理した砂分を洗浄処理する第2工程と、
前記第1工程で分級処理した細粒子分を凝集沈殿させて沈殿汚泥と処理水とに分離し、沈殿汚泥を脱水処理して濃縮残渣と処理水とに分離する第3工程と、を有し、
前記第1工程では、前記汚染土壌に陽イオンを添加する陽イオン添加工程を行うことを特徴とする汚染土壌の洗浄分級処理方法。
A first step of adding water to the contaminated soil and further classifying the slurry-like sediment from which coarse particles have been separated by wet sieve classification, into sand and fine particles;
A second step of washing the sand classified in the first step;
The fine particles fractionated in the first step are coagulated and precipitated to be separated into precipitated sludge and treated water, and the sedimented sludge is dewatered to be separated into concentrated residue and treated water, and the third step ,
In the first step, there is provided a cation addition step of adding a cation to the contaminated soil, and the method for washing and classifying contaminated soil.
前記陽イオン添加工程は、前記汚染土壌に前記水とともに前記陽イオンを添加する請求項1に記載の汚染土壌の洗浄分級処理方法。   The said cation addition process adds the said cation to the said contaminated soil with the said water, The washing classification processing method of the contaminated soil of Claim 1 characterized by the above-mentioned. 前記陽イオン添加工程は、前記汚染土壌のうちの湿式ふるい分級処理して前記粗粒子分を分離した後の前記スラリー状の土砂に前記陽イオンを添加する請求項1に記載の汚染土壌の洗浄分級処理方法。   The said cation addition process adds the said cation to the said slurry-like earth and sand after the wet sieve classification process of the said contaminated soil and isolate | separating the said coarse particle part. Classification processing method. 前記陽イオン添加工程は、前記汚染土壌のうちの前記砂分と前記細粒子分とに分級処理された後の前記細粒子分に前記陽イオンを添加する請求項1に記載の汚染土壌の洗浄分級処理方法。   The said cation addition process adds the said cation to the said fine particle fraction after the classification process to the said sand component and the said fine particle fraction of the said contaminated soil, The cleaning of the contaminated soil of Claim 1 characterized by the above-mentioned. Classification processing method.
JP2017239666A 2017-12-14 2017-12-14 Cleaning classification processing method of contaminated soil Pending JP2019103989A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2017239666A JP2019103989A (en) 2017-12-14 2017-12-14 Cleaning classification processing method of contaminated soil

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2017239666A JP2019103989A (en) 2017-12-14 2017-12-14 Cleaning classification processing method of contaminated soil

Publications (1)

Publication Number Publication Date
JP2019103989A true JP2019103989A (en) 2019-06-27

Family

ID=67062607

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2017239666A Pending JP2019103989A (en) 2017-12-14 2017-12-14 Cleaning classification processing method of contaminated soil

Country Status (1)

Country Link
JP (1) JP2019103989A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2020127915A (en) * 2019-02-08 2020-08-27 株式会社大林組 Modified soil classification method
JP2020163265A (en) * 2019-03-29 2020-10-08 株式会社奥村組 Classification cleaning treatment method of contaminated soil
CN113578749A (en) * 2021-07-22 2021-11-02 中国热带农业科学院热带作物品种资源研究所 Grading method for grain size of rice soil
JP7496088B2 (en) 2020-11-26 2024-06-06 鹿島建設株式会社 Soil treatment and classification methods
JP7500003B2 (en) 2020-03-27 2024-06-17 清水建設株式会社 Contaminated soil cleaning and classification treatment system and contaminated soil cleaning and classification treatment method

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2020127915A (en) * 2019-02-08 2020-08-27 株式会社大林組 Modified soil classification method
JP2020163265A (en) * 2019-03-29 2020-10-08 株式会社奥村組 Classification cleaning treatment method of contaminated soil
JP7500003B2 (en) 2020-03-27 2024-06-17 清水建設株式会社 Contaminated soil cleaning and classification treatment system and contaminated soil cleaning and classification treatment method
JP7496088B2 (en) 2020-11-26 2024-06-06 鹿島建設株式会社 Soil treatment and classification methods
CN113578749A (en) * 2021-07-22 2021-11-02 中国热带农业科学院热带作物品种资源研究所 Grading method for grain size of rice soil

Similar Documents

Publication Publication Date Title
JP2019103989A (en) Cleaning classification processing method of contaminated soil
JP5769082B2 (en) Cleaning treatment method for radioactive material contaminated soil
JP2006116397A (en) Washing method and washing apparatus of contaminated soil
US20190329267A1 (en) Method and apparatus for washing and grading silica sand for glass production
RU2407594C1 (en) Gravity method of removing high-ash slime from coal dressing muddy water circuit
CN103002998A (en) Soil cleaning method
JP5990442B2 (en) Volume reduction treatment method for contaminated soil
JP5155487B1 (en) Classification method of contaminated soil
US4325819A (en) Coal washing plant
US10351454B2 (en) Mining apparatus with water reclamation system
JP6027921B2 (en) Treatment method of contaminated soil
TWI549764B (en) A treating method of removing heavy metals in soil grains with mobility
JP5818096B2 (en) Cleaning treatment method for cesium contaminated soil
JP5818095B2 (en) Cleaning treatment method for cesium contaminated soil
JP4697719B2 (en) Method for purifying contaminated soil and separation apparatus used therefor
JP2013140021A (en) Cleaning and volume reduction method of radioactive substance-contaminated soil
JP6312016B2 (en) Contaminated soil treatment equipment
US20220001391A1 (en) System and method for recovering desired materials using a ball mill or rod mill
JP5276779B2 (en) Purification method for sediment and soil contaminated with dioxins
UA127651C2 (en) Method and arrangement for process water treatment
KR101129876B1 (en) Complex method for remediation of soil being contaminated by highly concentrated heavy metal
JP6618039B2 (en) Decontamination soil treatment apparatus and method
JP2005262076A (en) Method for cleaning soil contaminated with oil
JP7500003B2 (en) Contaminated soil cleaning and classification treatment system and contaminated soil cleaning and classification treatment method
JP5983992B2 (en) Cleaning treatment method for cesium contaminated soil