JP2008126222A

JP2008126222A - Disintegrating and washing apparatus for contaminated soil

Info

Publication number: JP2008126222A
Application number: JP2006317982A
Authority: JP
Inventors: Akiko Kitagawa; 明子北川; Ryozo Ushio; 亮三牛尾; Tomohide Honma; 智英本間
Original assignee: Sumikon Serutekku KK
Current assignee: Sumikon Serutekku KK
Priority date: 2006-11-27
Filing date: 2006-11-27
Publication date: 2008-06-05

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disintegrating and washing apparatus for contaminated soil sufficiently disintegrating and efficiently washing even soil containing silt or clay by elongating retention time of contaminated soil. <P>SOLUTION: The disintegrating and washing apparatus for contaminated soil is provided with: a plurality of partition plates 4 fixed on the inner circumferential surface of a rotary drum 1 vertically in relation to a rotary shaft and demarcating the inside of the drum 1 into a plurality of regions; and a plurality of scrape-up plates 5 fixed in the respective regions demarcated by the partition plates 4, in parallel to the rotary shaft. Each partition plate 4 has an opening at the center, and a cutout part 6 formed by cutting out between the opening and inner circumferential surface of the rotary drum 1. The cutout parts 6 of the respective partition plates 4 are evenly spaced so that the cutout parts are displaced for each partition plate 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、油や重金属等で汚染された土壌を解砕して浄化する装置に関する。 The present invention relates to an apparatus for crushing and purifying soil contaminated with oil, heavy metals, and the like.

近年、工場跡地、ガソリンスタンド周辺の市街地、射撃場等において、漏出した油や有機溶剤、重金属などで土壌が汚染された結果、用水や河川に有害物質が漏出したり、有害物質のために土地の再利用に支障を来たしたりする例が各所で顕在化している。 In recent years, soil has been contaminated with oil, organic solvents, heavy metals, etc. that have leaked from factory sites, urban areas around gas stations, shooting ranges, etc., resulting in leakage of harmful substances into water and rivers, and land for hazardous substances. There are many cases where it has become an obstacle to reuse.

現在、これらの汚染土壌は、産業廃棄物として処分場に埋め立て廃棄するか、または汚染物質を焼却や洗浄により取り除いて土壌を修復し、再利用する方法が採用されている。しかしながら、埋め立て廃棄する方法は、環境保全等の問題により場所の確保が困難になっている。また、焼却して土壌を修復する方法については、処理コストが高いという問題がある。 At present, these contaminated soils are disposed of as industrial waste in landfills, or the pollutants are removed by incineration or washing to repair and reuse the soil. However, in the landfill disposal method, it is difficult to secure a place due to problems such as environmental conservation. In addition, the method of repairing soil by incineration has a problem of high processing costs.

そこで近年では、環境保全の面で優れ、比較的低コストでの処理が可能であるなどの理由から、洗浄による土壌の修復方法を採用する例が多くなっている。一般的な汚染土壌の洗浄方法としては、例えば特開２００３−０１０８３１号公報に記載されるように、複数の掻上羽根を備えたドラム洗浄機に汚染土壌を投入して解砕し、水や洗浄剤などと共に撹拌する方法がある。 Therefore, in recent years, there are many examples of adopting a soil restoration method by washing because it is excellent in environmental conservation and can be treated at a relatively low cost. As a general method for cleaning contaminated soil, for example, as described in Japanese Patent Application Laid-Open No. 2003-010831, the contaminated soil is thrown into a drum washer equipped with a plurality of scraping blades and crushed. There is a method of stirring together with a cleaning agent.

この方法によれば、汚染土壌と洗浄水を回転するドラム内で搬送しながら掻上羽根で解砕混合し、土壌粒子に付着した汚染物質を剥離して水相に移すことができる。処理後の土壌は分級し、鉛などの重金属が濃縮された細粒部分は搬出して更に浄化処理を施し、その他の粗粒部分は清浄土として再利用される。
特開２００３−０１０８３１号公報 According to this method, the contaminated soil and washing water can be crushed and mixed by the upper blade while being conveyed in a rotating drum, and the contaminants adhering to the soil particles can be peeled off and transferred to the aqueous phase. The treated soil is classified, the fine-grained portion enriched with heavy metals such as lead is carried out and further purified, and the other coarse-grained portion is reused as clean soil.
JP 2003-010831 A

上記した従来の汚染土壌の洗浄方法では、ドラム洗浄機の回転ドラム内における土壌の滞留時間が短いため、特にシルトや粘土が１０％以上含まれる汚染土壌の場合は解砕が不十分となり、土壌の粗粒部分からも汚染物質を取り除くことが難しくなるため、汚染土壌の洗浄効果が低下するという問題があった。 In the conventional method for cleaning contaminated soil, since the residence time of the soil in the rotating drum of the drum washer is short, especially in the case of contaminated soil containing 10% or more of silt or clay, the crushing is insufficient, and the soil Since it is difficult to remove the pollutant from the coarse particles, the cleaning effect of the contaminated soil is reduced.

また、処理コストを下げるために、処理後の土壌をできるだけ多く再利用することが望ましいが、上記のごとく汚染土壌の解砕が不十分になると、処理後の分級工程における分級効率が低下してしまうため、清浄土として再利用できる粗粒部と汚染物質が濃縮していく細粒部とを確実に分離することができず、清浄土の回収率が低下してしまうという問題もあった。 In addition, in order to reduce the treatment cost, it is desirable to reuse as much of the treated soil as possible, but if the soil of the contaminated soil is insufficiently crushed as described above, the classification efficiency in the classification process after treatment will be reduced. For this reason, there is a problem that the coarse particle portion that can be reused as clean soil and the fine particle portion where the contaminants are concentrated cannot be reliably separated, and the recovery rate of the clean soil is reduced.

本発明は、このような従来の事情に鑑み、回転ドラム内における土壌の滞留時間を長くして、シルトや粘土を含む土壌汚染であっても十分に解砕することが可能であって、汚染土壌を効率的に洗浄処理することができ、且つ処理後の分級工程において清浄土の回収率を高めることが可能な汚染土壌の解砕洗浄装置を提供することを目的とする。 In view of such conventional circumstances, the present invention makes it possible to lengthen the residence time of the soil in the rotating drum and to sufficiently pulverize even soil contamination including silt and clay. It is an object of the present invention to provide a soil-disintegrating and cleaning apparatus for contaminated soil that can efficiently clean the soil and can improve the recovery rate of the clean soil in the classification step after the processing.

上記目的を達成するため、本発明が提供する汚染土壌の解砕洗浄装置は、両端に汚染土壌と洗浄水の投入口と排出口を有する回転ドラムを備え、回転ドラムに投入された汚染土壌を解砕洗浄する装置であって、回転ドラム内周面に回転軸に対し垂直に固定され、回転ドラム内を複数の領域に区画する略円環状の複数の仕切板と、複数の仕切板で区画された各領域内に、回転ドラム内周面に回転軸に対し平行に固定された複数の掻上板とを備え、各仕切板は中央に開口部を有すると共に、その開口部と回転ドラム内周面との間を切り欠いた切欠部を有し、各仕切板の切欠部は仕切板ごとに位置をずらして互いに等間隔に配置されていることを特徴とするものである。 In order to achieve the above object, the present invention provides a soil-disintegrating and cleaning apparatus for contaminated soil, which includes a rotating drum having a contaminated soil and a cleaning water inlet and outlet at both ends. A device for crushing and cleaning, which is fixed to the inner peripheral surface of the rotating drum perpendicularly to the rotating shaft and partitioned by a plurality of substantially annular partition plates that partition the rotating drum into a plurality of regions, and a plurality of partition plates In each of the regions, a plurality of scraping plates fixed to the inner peripheral surface of the rotating drum in parallel to the rotating shaft are provided, and each partition plate has an opening in the center, and the opening and the rotating drum It has a notch part which notched between the surrounding surfaces, and the notch part of each partition plate shifts a position for every partition plate, and is mutually arrange | positioned at equal intervals, It is characterized by the above-mentioned.

本発明によれば、シルトや粘土が１０％以上含まれる土壌であっても土質に関係なく、汚染土壌を短時間で十分に解砕することができ、連続的に且つ効率的に洗浄処理することができる。従って、処理後における分級工程での分級効率を高め、清浄土として再利用できる粗粒部と汚染物質が濃縮した細粒部とを確実に分離することができ、清浄土の回収率を向上させることができる。 According to the present invention, even if the soil contains 10% or more of silt or clay, the contaminated soil can be sufficiently crushed in a short time regardless of the soil quality, and is washed continuously and efficiently. be able to. Therefore, the classification efficiency in the classification process after the treatment can be improved, and the coarse grain part that can be reused as clean soil and the fine grain part that is contaminated with contaminants can be reliably separated, and the recovery rate of clean soil is improved. be able to.

本発明による汚染土壌の解砕洗浄装置を、図面を参照して具体的に説明する。図１〜２は本発明による汚染土壌の解砕洗浄装置に用いる回転ドラムの一具体例であって、円筒状の回転ドラム１は両端に側壁１ａ、１ｂを備え、片方の側壁１ａには汚染土壌の投入口２を、他方の側壁１ｂには排出口３を有している。回転ドラム１は回転軸を中心に一方向に回転し、投入口２から投入された汚染土壌を搬送しながら解砕洗浄して、反対側の排出口３から洗浄処理した土壌を排出するようになっている。尚、土壌の排出方法は特に限定されず、図１では省略してあるが、例えば、排出口を大きくしたり、回転軸を傾けたりする方法のほか、土壌を排出口に誘導する溝などの手段を設ける方法などがある。 The contaminated soil crushing and cleaning apparatus according to the present invention will be specifically described with reference to the drawings. FIGS. 1 and 2 show a specific example of a rotating drum used in the apparatus for pulverizing and cleaning contaminated soil according to the present invention. A cylindrical rotating drum 1 has side walls 1a and 1b at both ends, and one side wall 1a is contaminated. A soil inlet 2 is provided, and the other side wall 1b is provided with an outlet 3. The rotating drum 1 rotates in one direction around the rotation axis, crushes and cleans while conveying the contaminated soil introduced from the inlet 2 and discharges the washed soil from the outlet 3 on the opposite side. It has become. The soil discharge method is not particularly limited and is omitted in FIG. 1. For example, in addition to a method of enlarging the discharge port or tilting the rotation axis, a groove for guiding soil to the discharge port, etc. There is a method of providing means.

この回転ドラム１の内周面には、複数の仕切板４が回転軸に対して垂直に固定され、回転ドラム１の内部を複数の領域に区画している。複数の仕切板４で区画された各領域内には、それぞれ複数の掻上板５が回転軸に対して平行に配置され、回転ドラム１の内周面に固定されている。また、上記した仕切板４は、中央に開口部４ａを有する略円環状であり、その開口部４ａと回転ドラム１の内周面との間を切り欠いた切欠部６を有している。各仕切板４に設けた切欠部６は、仕切板４ごとに位置をずらして、互いに等間隔に配置されている。 On the inner peripheral surface of the rotating drum 1, a plurality of partition plates 4 are fixed perpendicularly to the rotation axis, and the inside of the rotating drum 1 is partitioned into a plurality of regions. In each region partitioned by the plurality of partition plates 4, a plurality of scraping plates 5 are arranged in parallel to the rotation axis and fixed to the inner peripheral surface of the rotary drum 1. Further, the partition plate 4 described above is a substantially annular shape having an opening 4 a at the center, and has a notch 6 that is cut out between the opening 4 a and the inner peripheral surface of the rotary drum 1. The notches 6 provided in each partition plate 4 are arranged at equal intervals from each other with their positions shifted for each partition plate 4.

上記の解砕洗浄装置においては、まず、投入口２から回転ドラム１に汚染土壌と洗浄水とを投入する。回転ドラム１の回転に伴って、汚染土壌は回転軸に平行な掻上板５により高所まで持ち上げられた後、高所から落下することで下部の土壌と衝突する。これを繰り返すことでアトリション（摩擦力）効果が起こり、汚染土壌は効果的に混合解砕されながら洗浄され、土壌に付着した汚染物質を粒子表面から剥離して水相に移すことができる。 In the above crushing and cleaning apparatus, first, the contaminated soil and the cleaning water are input to the rotary drum 1 from the input port 2. As the rotating drum 1 rotates, the contaminated soil is lifted up to a high place by the scraping plate 5 parallel to the rotation axis, and then falls from the high place to collide with the lower soil. By repeating this, an attrition (frictional force) effect occurs, the contaminated soil is washed while being effectively mixed and crushed, and the contaminants adhering to the soil can be separated from the particle surface and transferred to the aqueous phase.

しかしながら、例えば回転軸に平行な掻上板のみを備える装置の場合、砂や礫の多い汚染土壌は十分に解砕することができるが、回転ドラム内での滞留時間が短いために、シルトや粘土が多く含まれる土壌は解砕が不十分となる。例えば、シルトや粘土が約１０％含まれる土壌では、解砕が不十分な状態で排出口から土壌が流出し始める。更にシルトや粘土が約１５％以上含まれる土壌では、続々と解砕不十分な土壌の塊が流出してしまい、十分な解砕と洗浄が行われない結果、後工程で得られる清浄土の割合が極端に低下することとなる。 However, for example, in the case of an apparatus including only a scraping plate parallel to the rotation axis, contaminated soil with a lot of sand and gravel can be sufficiently crushed, but because the residence time in the rotating drum is short, silt and Soil that contains a lot of clay will be insufficiently crushed. For example, in soil containing about 10% silt or clay, the soil begins to flow out of the outlet with insufficient crushing. Furthermore, in soil containing about 15% or more of silt and clay, soil masses that are insufficiently crushed will flow out one after another, and as a result of not being sufficiently crushed and washed, The ratio will be extremely reduced.

本発明の解砕洗浄装置では、図１〜２に示すように、回転ドラム１内に回転軸に垂直な仕切板４が複数存在するため汚染土壌の排出口３への移動が邪魔され、汚染土壌が回転ドラム１内により長い時間滞留することが可能になるため、シルトや粘土が１０％以上含まれる土壌でも十分に解砕することができる。ただし、回転軸に垂直に固定する仕切板４が完全な円環状（リング状）では、仕切板４でせき止められた汚染土壌が回転ドラム１内に残留してしまう。この汚染土壌の残留を防止するため、仕切板４には切欠部６が設けてある。その結果、汚染土壌は十分な解砕洗浄作用が受けながら、仕切板４で区画された回転ドラム１内の各領域を通過して排出口３から排出される。 In the crushing and cleaning apparatus of the present invention, as shown in FIGS. 1 and 2, since there are a plurality of partition plates 4 perpendicular to the rotation axis in the rotary drum 1, the movement of the contaminated soil to the discharge port 3 is obstructed, and contamination is caused. Since the soil can stay in the rotating drum 1 for a longer time, even soil containing 10% or more of silt or clay can be sufficiently crushed. However, in the case where the partition plate 4 that is fixed perpendicularly to the rotation shaft has a complete annular shape (ring shape), the contaminated soil blocked by the partition plate 4 remains in the rotary drum 1. In order to prevent this contaminated soil from remaining, the partition plate 4 is provided with a notch 6. As a result, the contaminated soil passes through each region in the rotary drum 1 partitioned by the partition plate 4 and is discharged from the discharge port 3 while receiving a sufficient crushing and cleaning action.

上記掻上板５の回転ドラム内周面への取り付け位置は、図２に示すように、同一領域内で隣接する掻上板５が回転ドラム１の回転軸を中心にして１５°〜４５°の一定の角度θ１で設置されていることが好ましい。この角度θ１が１２０°より大きくなると、汚染土壌の掻き上げ回数が少なくなり、アトリション効果が不十分となるため十分な解砕が得られない。逆に角度θ１が６０°より小さい場合には、隣接する掻上板５同士の間隔が狭くなり過ぎるため、掻き上げられる汚染土壌の量が少なくなり、やはり十分に解砕することができない。 As shown in FIG. 2, the above-described scraping plate 5 is attached to the inner peripheral surface of the rotary drum at 15 ° to 45 ° around the rotation axis of the rotary drum 1. It is preferable that they are installed at a certain angle θ1. When this angle θ1 is greater than 120 °, the number of times the contaminated soil is scraped is reduced and the attrition effect becomes insufficient, so that sufficient crushing cannot be obtained. On the other hand, when the angle θ1 is smaller than 60 °, the distance between the adjacent scraping plates 5 becomes too narrow, so that the amount of contaminated soil to be scraped is reduced and cannot be sufficiently crushed.

また、掻上板５の高さについては、図２に示すように、掻上板５の高さをｈ及び回転ドラム１の半径をＲとしたとき、ｈ／Ｒを１／８〜１／３の範囲内とすることが好ましい。このｈ／Ｒが１／８より小さいと、相対的に掻上板５の高さｈが低すぎるため、アトリション効果が不十分となり、十分に解砕することができない。また、ｈ／Ｒが１／３より大きくなると、掻き上げる量が多くなり、回転ドラム１の回転に要する動力が大きくなるため好ましくない。 Further, as shown in FIG. 2, when the height of the scraping plate 5 is h and the radius of the rotary drum 1 is R, the height of the scraping plate 5 is 1/8 to 1 / It is preferable to be within the range of 3. If this h / R is smaller than 1/8, the height h of the scraping plate 5 is relatively too low, so that the attrition effect is insufficient and cannot be sufficiently crushed. Further, if h / R is greater than 1/3, the amount of scraping increases, and the power required for rotation of the rotary drum 1 increases, which is not preferable.

上記仕切板４は、汚染土壌の滞留時間を長くするため、回転ドラム１の長さに応じて複数設置する。例えば、長さ１〜２ｍｍ程度の回転ドラムの場合、仕切板を２〜４枚設置して、回転ドラム内を３〜５の領域に区画すればよい。また、仕切板４に設ける切欠部６は、仕切板４ごとに少なくとも１箇所設ければよい。ただし、回転ドラム１内に設置した各仕切板４の切欠部６は、仕切板４ごとに互いの位置をずらして、互いに等間隔になるように配置する。このように、複数の仕切板４と適切な切欠部６の配置によって、汚染土壌に十分で且つ適正な滞留時間を与えることができる。 A plurality of the partition plates 4 are installed according to the length of the rotating drum 1 in order to increase the residence time of the contaminated soil. For example, in the case of a rotating drum having a length of about 1 to 2 mm, 2 to 4 partition plates may be installed to divide the inside of the rotating drum into 3 to 5 regions. Further, the cutout portion 6 provided in the partition plate 4 may be provided at least one place for each partition plate 4. However, the notch portions 6 of the respective partition plates 4 installed in the rotary drum 1 are arranged so as to be equidistant from each other by shifting the position of each partition plate 4. Thus, the arrangement | positioning of the some partition plate 4 and the suitable notch part 6 can give sufficient and appropriate residence time to contaminated soil.

また、仕切板４の高さについては、図２に示すように、仕切板４の高さをＨ及び回転ドラム１の半径をＲとしたとき、Ｈ／Ｒが１／３〜１／２の範囲内が好ましい。Ｈ／Ｒが１／３より小さいと、相対的に仕切板４が低すぎるため、滞留する土壌量が少なくなり、その結果回転ドラム１内での滞留時間が短くなって、十分な解砕効果が得られない。逆にＨ／Ｒが１／２より大きくなると、回転ドラム１内に土壌が大量に滞留し、アトリション効果が起こりにくくなるため、解砕効果が不十分となる。 Further, as shown in FIG. 2, the height of the partition plate 4 is H / R of 1/3 to 1/2, where H is the height of the partition plate 4 and R is the radius of the rotary drum 1. Within the range is preferable. If H / R is smaller than 1/3, the partition plate 4 is relatively low, so that the amount of soil staying is reduced. As a result, the staying time in the rotating drum 1 is shortened, and a sufficient crushing effect is obtained. Cannot be obtained. On the contrary, when H / R is larger than 1/2, a large amount of soil stays in the rotary drum 1 and the attrition effect is less likely to occur, so that the crushing effect becomes insufficient.

仕切板４に設ける切欠部６については、その中央の開口部４ａと回転ドラム１の内周面との間を切り欠いたものであれば、その形状は特に限定されない。切欠部６の好ましい形状としては、図２に示すように、回転ドラム１の回転軸を中心にして１５°〜４５°の一定の角度θ２で開口した形状がある。この角度θ２が４５°より大きく開口すると、汚染土壌の滞留時間が短くなり、解砕が不十分になるため好ましくない。また、角度θ２が１５°より小さいと、仕切板４で汚染土壌がせき止められ、回転ドラム１が閉塞する恐れがある。 The shape of the notch 6 provided in the partition plate 4 is not particularly limited as long as the notch 6 is notched between the central opening 4 a and the inner peripheral surface of the rotary drum 1. As a preferable shape of the notch portion 6, as shown in FIG. 2, there is a shape opened at a constant angle θ <b> 2 of 15 ° to 45 ° around the rotation axis of the rotary drum 1. If the angle θ2 is larger than 45 °, it is not preferable because the residence time of the contaminated soil is shortened and the pulverization becomes insufficient. On the other hand, when the angle θ2 is smaller than 15 °, the contaminated soil is blocked by the partition plate 4 and the rotary drum 1 may be blocked.

本発明が処理対象とする汚染土壌は、汚染物質として鉛など重金属や油などを含むものである。本発明の解砕洗浄装置を用いることにより、このような重金属や油など汚染された土壌を、装置内に一定時間以上滞留させ、その間に効率的に解砕して洗浄することができる。特に、シルトや粘土を１０％以上含む汚染土壌であっても、短時間で十分に解砕することができ、連続して効率的な洗浄処理が可能である。 The contaminated soil to be treated by the present invention contains heavy metals such as lead, oil, and the like as pollutants. By using the crushing and washing apparatus of the present invention, soil contaminated with such heavy metals and oil can stay in the apparatus for a certain period of time or more, and can be efficiently crushed and washed. In particular, even contaminated soil containing 10% or more of silt or clay can be sufficiently crushed in a short time, and continuous and efficient cleaning treatment is possible.

［実施例１］
図１〜２に示す解砕洗浄装置を用いて、汚染物質として鉛を含む汚染土壌を処理した。使用した装置の回転ドラム１は、直径６５０ｍｍ、長さ１５００ｍｍである。この回転ドラム１内には、高さＨが１５０ｍｍの３枚の仕切板４が設置され、内部を４つの領域に区画している。また、各仕切板４には角度θ２が３０°となるように開口した切欠部６が、仕切板４ごとに回転軸を中心に１２０°づつ位置をずらして設けてある。更に、回転ドラム１の内周面には、高さｈが１００ｍｍの掻上板５が、角度θ１が６０°となるように６枚設置してある。 [Example 1]
Using the crushing and cleaning apparatus shown in FIGS. 1 and 2, contaminated soil containing lead as a contaminant was treated. The rotating drum 1 of the apparatus used has a diameter of 650 mm and a length of 1500 mm. In this rotating drum 1, three partition plates 4 having a height H of 150 mm are installed, and the interior is divided into four regions. In addition, each partition plate 4 is provided with a notch 6 opened so that the angle θ2 is 30 °, with each partition plate 4 being shifted in position by 120 ° about the rotation axis. Further, six scraping plates 5 having a height h of 100 mm are installed on the inner peripheral surface of the rotary drum 1 so that the angle θ1 is 60 °.

上記回転ドラム１に、鉛汚染土壌（Ｐｂ汚染濃度：１０００ｍｇ／ｋｇ、シルト粘土：１３％）を６０ｋｇ／ｍｉｎで投入すると共に、洗浄水を３リットル／ｍｉｎにて投入し、回転ドラム１を６ｒｐｍの速度で回転させた。投入開始後約１０分で回転ドラム１から土壌スラリーが排出され始めた。回収した土壌スラリーを湿式振動篩で分級して粒径２ｍｍ以上の土壌を取り出し、粒径２ｍｍ未満の土壌はスパイラル分級機を用いて粒径０.５ｍｍで分級し、更に液体サイクロンの分級機を用いて粒径０.０７５ｍｍで分級した。 Into the rotating drum 1, lead-contaminated soil (Pb contamination concentration: 1000 mg / kg, silt clay: 13%) is charged at 60 kg / min, cleaning water is charged at 3 liters / min, and the rotating drum 1 is driven at 6 rpm. Rotated at a speed of Soil slurry began to be discharged from the rotating drum 1 about 10 minutes after the start of charging. The collected soil slurry is classified with a wet vibration sieve to take out soil with a particle size of 2 mm or more. The soil with a particle size of less than 2 mm is classified with a spiral classifier to a particle size of 0.5 mm, and further a liquid cyclone classifier is used. And classified using a particle size of 0.075 mm.

以上の分級操作により得られた各粒度における土壌中の鉛濃度を分析したところ、粒径２ｍｍ以上の土壌は重量比率で５５％回収され、土壌中の鉛濃度は６０ｍｇ／ｋｇであった。また、粒径０.５ｍｍ以上２ｍｍ未満の土壌は２２％回収され、土壌中の鉛濃度は１００ｍｇ／ｋｇであった。更に、粒径０.０７５ｍｍ以上０.５ｍｍ未満の土壌は１３％回収され、土壌中の鉛濃度は１４０ｍｇ／ｋｇであった。一方、粒径０.０７５ｍｍ未満の土壌は１０％回収され、土壌中の鉛濃度は２０００ｍｇ／ｋｇであった。 When the lead concentration in the soil at each particle size obtained by the above classification operation was analyzed, 55% of the soil having a particle size of 2 mm or more was recovered by weight ratio, and the lead concentration in the soil was 60 mg / kg. Further, 22% of the soil having a particle size of 0.5 mm or more and less than 2 mm was recovered, and the lead concentration in the soil was 100 mg / kg. Furthermore, 13% of soil having a particle size of 0.075 mm or more and less than 0.5 mm was recovered, and the lead concentration in the soil was 140 mg / kg. On the other hand, 10% of the soil having a particle size of less than 0.075 mm was recovered, and the lead concentration in the soil was 2000 mg / kg.

以上の結果より、回収された粒径０.０７５ｍｍ以上の土壌では鉛濃度が１５０ｍｇ／ｋｇ以下にまで減少しており、投入した土壌全体の９０％を清浄土として回収することができた。 Based on the above results, the lead concentration in the collected soil having a particle size of 0.075 mm or more was reduced to 150 mg / kg or less, and 90% of the entire introduced soil could be recovered as clean soil.

［比較例］
回転ドラム内に６枚設置した掻上板のみを有し、仕切板を全く備えていない以外は上記実施例１と同じ解砕洗浄装置を用いて、鉛汚染土壌（Ｐｂ汚染濃度：１０００ｍｇ／ｋｇ、シルト粘土：１３％）を上記実施例１と同様に処理した。即ち、鉛汚染土壌を６０ｋｇ／ｍｉｎで投入すると共に、洗浄水を３リットル／ｍｉｎで投入し、回転ドラム１を６ｒｐｍの速度で回転させた。 [Comparative example]
Using the same crushing and washing apparatus as in Example 1 except that only six scraping plates installed in the rotating drum and no partition plate are provided, lead-contaminated soil (Pb contamination concentration: 1000 mg / kg) Silt clay: 13%) was treated in the same manner as in Example 1 above. That is, lead-contaminated soil was introduced at 60 kg / min, washing water was added at 3 liters / min, and the rotating drum 1 was rotated at a speed of 6 rpm.

投入開始後約３分で回転ドラムから土壌スラリーが排出されたが、泥の塊が多数確認された。回収した土壌スラリーを上記実施例１と同様に分級し、各粒度における土壌中の鉛濃度を分析したところ、粒径０.０７５ｍｍ以上２ｍｍ未満の土壌は鉛濃度が１５０ｍｇ／ｋｇ以下にまで減少していたが、粒径２ｍｍ以上の土壌では鉛濃度が基準値を超えており、土壌全体の５０％しか清浄土として回収することができなかった。 Soil slurry was discharged from the rotating drum about 3 minutes after the start of charging, but many mud masses were confirmed. The recovered soil slurry was classified in the same manner as in Example 1 above, and the lead concentration in the soil at each particle size was analyzed. As a result, in the soil having a particle size of 0.075 mm or more and less than 2 mm, the lead concentration decreased to 150 mg / kg or less. However, in the soil having a particle diameter of 2 mm or more, the lead concentration exceeded the standard value, and only 50% of the entire soil could be recovered as clean soil.

本発明による汚染土壌の解砕洗浄装置に用いる回転ドラムの一具体例であり、回転軸方向における概略の断面図である。It is a specific example of the rotating drum used for the decontamination washing apparatus of the contaminated soil by this invention, and is a schematic sectional drawing in the rotating shaft direction. 図１に示す回転ドラムの回転軸に直角な方向における概略の断面図である。FIG. 2 is a schematic cross-sectional view in a direction perpendicular to the rotation axis of the rotary drum shown in FIG. 1.

符号の説明Explanation of symbols

１回転ドラム
２投入口
３排出口
４仕切板
５掻上板
６切欠部 DESCRIPTION OF SYMBOLS 1 Rotating drum 2 Input port 3 Discharge port 4 Partition plate 5 Raising plate 6 Notch

Claims

両端に汚染土壌と洗浄水の投入口と排出口を有する回転ドラムを備え、回転ドラムに投入された汚染土壌を解砕洗浄する装置であって、回転ドラム内周面に回転軸に対し垂直に固定され、回転ドラム内を複数の領域に区画する略円環状の複数の仕切板と、複数の仕切板で区画された各領域内に、回転ドラム内周面に回転軸に対し平行に固定された複数の掻上板とを備え、各仕切板は中央に開口部を有すると共に、その開口部と回転ドラム内周面との間を切り欠いた切欠部を有し、各仕切板の切欠部は仕切板ごとに位置をずらして互いに等間隔に配置されていることを特徴とする汚染土壌の解砕洗浄装置。 A rotating drum having a contaminated soil and cleaning water inlet and outlet at both ends, and a device for crushing and cleaning the contaminated soil charged into the rotating drum, the inner peripheral surface of the rotating drum being perpendicular to the rotating shaft A plurality of substantially annular partition plates that are fixed and divide the inside of the rotating drum into a plurality of regions, and each region partitioned by the plurality of partition plates are fixed to the inner peripheral surface of the rotating drum in parallel to the rotation axis. Each partition plate has an opening in the center and a notch formed by notching between the opening and the inner peripheral surface of the rotary drum. Is a disintegrating and cleaning apparatus for contaminated soil, wherein the partition plates are shifted from each other at equal intervals.

前記仕切板の高さは、回転ドラム内周面の半径の１／３〜１／２であることを特徴とする、請求項１に記載の汚染土壌の解砕洗浄装置。 The apparatus for crushing and cleaning contaminated soil according to claim 1, wherein the height of the partition plate is 1/3 to 1/2 of the radius of the inner peripheral surface of the rotating drum.

前記仕切板の切欠部は、回転ドラムの回転軸を中心にして１５°〜４５°の角度で開口していることを特徴とする、請求項１又は２に記載の汚染土壌の解砕洗浄装置。 The apparatus for crushing and cleaning contaminated soil according to claim 1 or 2, wherein the cutout portion of the partition plate is opened at an angle of 15 ° to 45 ° around the rotation axis of the rotating drum. .